Patent Publication Number: US-2023133537-A1

Title: Prelithiation material and preparation method and use thereof

Description:
TECHNICAL FIELD 
     The present invention belongs to the technical field of energy storage. 
     Specifically, the present invention relates to a prelithiation material and a preparation method and use thereof. 
     Background Art 
     The irreversible capacity loss is caused by the formation of the solid electrolyte interface (SEI) at the negative electrode interface during the first cycle of lithium ion energy storage device, and the reduction of active lithium content will lead to a decrease in the energy density of the lithium ion energy storage device. Negative electrode materials in high specific energy storage devices often need to choose materials with higher specific capacities to increase energy density, such as alloy negative electrodes with high specific capacity. The alloy negative electrode needs to consume more active lithium than the graphite negative electrode during the first charge, which reduces the coulombic efficiency of the battery, resulting in a limited increase in the actual energy density. Therefore, the appropriate active prelithiation method has an important significance for the application of alloy negative electrodes and the improvement of the energy density of the lithium ion energy storage device. 
     Chinese Patent Publication No. CN1290209C discloses a method for compensating lithium in the negative electrode by adding lithium powder to compensate the loss of active lithium in a battery. However, this method requires a strict environmental control method in actual operations, otherwise it is easy to cause fire and explosion risk. 
     Chinese Patent Application No. CN201810282994 discloses a prelithiation material for a positive electrode, wherein a slurry prepared by using a Li 2 S-based material is coated on the surface of the positive electrode to provide active lithium. However, such a method is still limited by the problem that the prelithiation material reacts with moisture in the environment. 
     Application No. CN201310070202.9 has developed a prelithiation method for a positive electrode using an inorganic lithium salt modified by a silane coupling agent as a prelithiation agent. The battery containing the prelithiation material prepared by the method needs to be baked in an oven at 80-110° C. for 0.5-10 h after the first charging to realize the prelithiation performance. It is limited by the battery system and practical process compatibility. 
     Therefore, there is still a need in the industry to develop a lithium ion energy storage device with good air stability and practical ease of operation. 
     CONTENTS OF THE INVENTION 
     In order to compensate for the deficiencies of the prelithiation materials of the prior art, such as air stability and practical operability, the present invention provides a prelithiation material having air stability. The prelithiation material provided by the present invention is compatible with the preparation process of existing lithium ion energy storage devices, has low cost and is suitable for mass production. It can be widely used in industrial production. 
     The aforesaid object of the present invention is achieved by the following technical solutions: 
     In a first aspect, the present invention provides a prelithiation material comprising a lithium-containing compound and an inorganic non-metallic reductive agent. 
     Preferably, in the prelithiation material of the present invention, the prelithiation material further comprises a conductive agent. 
     Preferably, in the prelithiation material of the present invention, the conductive agent is coated on surfaces of the lithium-containing compound and the inorganic non-metallic reductive agent to form a conductive layer, or the conductive agent forms a uniform dispersion with the lithium-containing compound and the inorganic non-metallic reductive agent. 
     Preferably, in the prelithiation material of the present invention, the lithium-containing compound is one or more of lithium peroxide, lithium oxide, lithium carbonate, lithium metasilicate, lithium orthosilicate, and lithium phosphate; preferably, the lithium-containing compound is lithium phosphate and/or lithium orthosilicate. 
     Preferably, in the prelithiation material of the present invention, the inorganic non-metallic reductive agent is a substance capable of reducing a lithium-containing compound. 
     Preferably, in the prelithiation material of the present invention, the inorganic non-metallic reductive agent is one or more of elemental phosphorus, iron phosphide, boron phosphide, nickel phosphide, lithium phosphide, zinc phosphide, elemental boron, cobalt boride, molybdenum boride, calcium boride, magnesium boride, lanthanum boride, aluminum boride, tungsten boride, titanium boride, zirconium boride, chromium boride, elemental sulfur, titanium sulfide, zinc sulfide, lithium sulfide, iron sulfide, molybdenum sulfide, tungsten sulfide, cobalt sulfide, molybdenum nitride, niobium nitride, molybdenum carbide, indium iodide, lithium iodide, and nickel selenide; more preferably, the inorganic non-metallic reductive agent is one or more of boron phosphide, zinc phosphide, elemental boron, cobalt boride, molybdenum boride, lanthanum boride, calcium boride, aluminum boride, elemental sulfur, lithium sulfide, and titanium sulfide; further preferably, the inorganic non-metallic reductive agent is one or more of boron phosphide, elemental boron, lanthanum boride, calcium boride, lithium sulfide, elemental sulfur and titanium sulfide. 
     Preferably, in the prelithiation material of the present invention, the lithium-containing compound has a particle size of 10 nm-20 μm; more preferably, the lithium-containing compound has a particle size of 20 nm-200 nm. 
     Preferably, in the prelithiation material of the present invention, the inorganic non-metallic reductive agent has a particle size of from 10 nm-20 μm; more preferably, the inorganic non-metallic reductive agent has a particle size of nm-200 nm. 
     Preferably, in the prelithiation material of the present invention, the conductive agent is a material capable of transporting electrons. 
     Preferably, in the prelithiation material of the present invention, the conductive agent is an organic conductive polymer, a conductive carbon, or an inorganic conductive compound. 
     Preferably, in the prelithiation material of the present invention, the organic conductive polymer is polyaniline, polypyrrole, or polythiophene; the inorganic conductive compound is titanium nitride or indium tin oxide; the conductive carbon is graphene, carbon nanotubes, acetylene black, or Ketjen black. 
     Preferably, in the prelithiation material of the present invention, when the conductive agent is coated on surfaces of the lithium-containing compound and the inorganic non-metallic reductive agent to form the conductive layer, based on the total mass of the prelithiation material, the mass fraction of the lithium-containing compound is 50-90%, more preferably 60-80%; the mass fraction of the inorganic non-metallic reductive agent is 10-40%, more preferably 15-25%; and the mass fraction of the conductive agent is 0.05-20%, more preferably 2-10%. 
     Preferably, in the prelithiation material of the present invention, when the conductive agent is coated on surfaces of the lithium-containing compound and the inorganic non-metallic reductive agent to form the conductive layer, the conductive layer has a thickness of 2 nm-200 nm; more preferably, the conductive layer has a thickness of 2-50 nm. 
     Preferably, in the prelithiation material of the present invention, when the conductive agent forms a homogeneous dispersion with the lithium-containing compound and the inorganic non-metallic reductive agent, based on the total mass of the prelithiation material, the mass fraction of the conductive agent is 5-50%, preferably 10-30%, further preferably 15-20%. 
     In a second aspect, the present invention provides a method for preparing the prelithiation material of the present invention, comprising the steps of: 
     uniformly mixing a lithium-containing compound, an inorganic non-metallic reductive agent, and optionally a conductive agent to prepare the prelithiation material; or 
     uniformly mixing a lithium-containing compound and an inorganic non-metallic reductive agent, then introducing a conductive agent precursor and reacting the same on surfaces of the lithium-containing compound and the inorganic non-metallic reductive agent to form a conductive layer to prepare the prelithiation material. 
     Preferably, in the method of the present invention, the conductive agent precursor is a conductive polymer monomer, a saccharide, a pitch, a coke, an alkane gas, or an alkene gas. 
     Preferably, in the method of the present invention, the conductive agent precursor is aniline monomer, sucrose, glucose, paraffin oil, methane, acetylene, or ethylene. 
     In the method of the present invention, the method of coating a conductive agent on surfaces of a lithium-containing compound and an inorganic non-metallic reductive agent to form a conductive layer is not exclusive, and common methods known in the art may be used, for example, thermal cracking of carbon-containing compounds, chemical vapor deposition, ball-milled carbon coating, liquid-phase solvent thermal coating, in-situ chemical polymerization, and the like. 
     In the method of the present invention, the method of forming a uniform dispersion of the conductive agent with the lithium-containing compound and the inorganic non-metallic reductive agent is not exclusive, and a method commonly used in the art such as dry ball milling or wet ball milling may be used. 
     In a third aspect, the present invention also provides the use of the prelithiation material of the present invention or the prelithiation material prepared by the method of the present invention in a lithium ion battery. 
     Preferably, in the use of the present invention, the prelithiation material is used in the positive electrode of a lithium ion battery and/or in the positive electrode-facing surface of a separator of a lithium ion battery. 
     In a specific embodiment, the method of adding the prelithiation material of the present invention to the positive electrode of the lithium ion battery includes coating on the surface of a positive electrode current collector, adding to a positive electrode pole piece, coating on the surface of the positive electrode pole piece, or coating on the side of the separator close to the positive electrode. 
     Preferably, in the use of the present invention, the prelithiation material is 0.5-20%, more preferably 2-10%, based on the total mass of the positive electrode active material, and the positive electrode active material is composed of the prelithiation material and the positive electrode material. 
     In a fourth aspect, the present invention provides a prelithiation slurry comprising the prelithiation material of the present invention, further comprising a solvent, a binder, and optionally a conductive additive. 
     Preferably, in the prelithiation slurry of the present invention, the solvent is one or more of N-methyl pyrrolidone, water and absolute ethanol; the content of the solvent is 20-80% by weight of the prelithiation slurry, more preferably 60-75% by weight of the prelithiation slurry. 
     Preferably, in the prelithiation slurry of the present invention, the binder is one or more of polyvinylidene fluoride, sodium carboxymethyl cellulose and styrene-butadiene rubber; the content of the binder is 0.5-5% by weight of the prelithiation slurry, more preferably 2-5% by weight of the prelithiation slurry. 
     Preferably, in the prelithiation slurry of the present invention, the conductive additive is one or more of conductive graphite, acetylene black, carbon nanotube, nano powder and graphene; the content of the conductive additive is 0-10% by weight of the prelithiation slurry, more preferably 2-5% by weight of the prelithiation slurry. 
     In a fifth aspect, the present invention provides a lithium ion energy storage device comprising a prelithiation material of the present invention and a prelithiation slurry of the present invention on the surface of a positive electrode and/or a separator facing the positive electrode. 
     The present invention provides a method for preparing a composite prelithiation material based on a method of blending a lithium-containing compound with an inorganic reductive agent, and coating carbon at the interface, and the use of the composite prelithiation material as a positive electrode prelithiation agent in a lithium ion energy storage device. In the present invention, the lithium-containing compound is blended with an inorganic non-metallic reductive agent, and on this basis, effective electronic conductivity and air stability are achieved through interfacial carbon coating, so that the composite positive electrode prelithiation material is jointly constructed. 
     The present invention has the following advantageous effects: 
     The prelithiation material provided by the present invention is compatible with lithium ion battery manufacturing processes. By mixing the prelithiation material provided by the present invention with a positive electrode material or coating the side of separator near the positive electrode with the same, a battery is assembled, and during battery charge and discharge cycles, active lithium can be released so as to compensate active lithium lost from a negative electrode. The prelithiation material provided by the present invention has good compatibility with currently commercially available positive and negative electrodes, and is very suitable for current secondary lithium ion batteries without the need to adjust the redesign of electrolyte and battery manufacturing processes. In addition, the prelithiation material provided by the present invention has good air stability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein: 
         FIG.  1    is a first-cycle charge-discharge curve graph of a prelithiation material according to an example of the present invention; wherein a1 is the first-cycle charge-discharge curve of the pole piece numbered a1, and b3 is the first-cycle charge-discharge curve of the pole piece numbered b3; 
         FIG.  2    is an electron microscope image of a “core-shell structure” of a prelithiation material when a b3 pole piece is prepared according to an example of the present invention; 
         FIG.  3    is an electron microscope image of the “three-component homogeneous blend” of the prelithiation material of Example 10; 
         FIG.  4    is an electron microscope image of “two-component homogeneous blend” of the prelithiation material of Example 9; 
         FIG.  5    is a graph comparing the first-cycle charge-discharge curves of a lithium iron phosphate-graphite full battery (e0) without prelithiation material and lithium iron phosphate+5% prelithiation material-graphite full battery (e2) of Example 4;  FIG.  5    shows that the first-cycle charge-discharge capacity of e2 is increased by 30 mAh/g compared with that of e0; and 
         FIG.  6    is a graph comparing the cyclic charge-discharge curves of the lithium iron phosphate-graphite full battery (e0) without prelithiation material and lithium iron phosphate+5% prelithiation material-graphite full battery (e2) of Example 4;  FIG.  6    shows that both the cycle stability and capacity retention of e2 are improved compared with that of e0. 
     
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     The present invention is described in further detail below in connection with specific embodiments, which are given for the purpose of illustration only and are not intended to limit the scope of the present invention. 
     Example 1 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6  was used as a reductive agent; C 6 H 12 O 6  and C 12 H 22 O 11  were used as a conductive agent precursors; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b0. 
     2. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.01 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 2 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b1. 
     3. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.01 g of C 12 H 22 O 11  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 2 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b2. 
     4. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b3. 
     5. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.095 g of C 12 H 22 O 11  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b4. 
     6. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.2 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 50 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b5. 
     7. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.19 g of C 12 H 22 O 11  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 50 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b6. 
     8. 0.63 g of Li 3 PO 4 , 0.17 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as b7. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Carbon Thickness (nm) 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Carbon Source 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 b0 
                  0 Null 
                 11 
               
               
                   
                 b1 
                  2 C 6 H 12 O 6   
                 324 
               
               
                   
                 b2 
                  2 C 12 H 22 O 11   
                 317 
               
               
                   
                 b3 
                 30 C 6 H 12 O 6   
                 528 
               
               
                   
                 b4 
                 30 C 12 H 22 O 11   
                 509 
               
               
                   
                 b5 
                 50 C 6 H 12 O 6   
                 519 
               
               
                   
                 b6 
                 50 C 12 H 22 O 11   
                 498 
               
               
                   
                 b7 
                 30 C 6 H 12 O 6   
                 503 
               
               
                   
                   
               
            
           
         
       
     
     Example 2 
     In this example, Li 4 SiO 4  was used as a lithium-containing compound; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 0.50 g of Li 4 SiO 4 , 0.3 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as c1. 
     2. 0.60 g of Li 4 SiO 4 , 0.2 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as c2. 
     3. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as c3. 
     4. 0.67 g of Li 4 SiO 4 , 0.13 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as c4. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Lithium-containing 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 compound:reductive agent 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 c1 
                   5:3 
                 452 
               
               
                   
                 c2 
                   3:1 
                 476 
               
               
                   
                 c3 
                 3.7:1 
                 528 
               
               
                   
                 c4 
                 5.2:1 
                 509 
               
               
                   
                   
               
            
           
         
       
     
     Example 3 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent; Super-P was used as a conductive additive to fabricate a positive electrode pole piece. 
     1. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 20 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as d1. 
     2. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 50 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as d2. 
     3. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as d3. 
     4. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 200 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as d4. 
     5. 0.63 g of Li 3 PO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as d5. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Particle 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Size (nm) 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 d1 
                 20 
                 512 
               
               
                   
                 d2 
                 50 
                 520 
               
               
                   
                 d3 
                 100 
                 528 
               
               
                   
                 d4 
                 200 
                 519 
               
               
                   
                 d5 
                 100 
                 509 
               
               
                   
                   
               
            
           
         
       
     
     Example 4 
     In this example, LiFePO 4  was used as a positive electrode material; Li 4 SiO 4  was used as a lithium-containing compound; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent; Super-P was used as a conductive additive to fabricate a positive electrode pole piece. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling after mixing to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.8 g of LiFePO 4  and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as e0. 
     2. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.784 g of LiFePO 4 , 0.016 g of prelithiation material, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as e1. 
     3. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as e2. 
     4. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.72 g of LiFePO 4 , 0.08 g of prelithiation material, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as e3. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Ratio (%) of prelithiation 
                   
               
               
                   
                 Battery 
                 material to positive 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 electrode active material 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 e0 
                 0 
                 152 
               
               
                   
                 e1 
                 2 
                 159 
               
               
                   
                 e2 
                 5 
                 182 
               
               
                   
                 e3 
                 10 
                 191 
               
               
                   
                   
               
            
           
         
       
     
     Example 5 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 1.04 g of Li 4 SiO 4  and 0.28 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.166 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.1 g of NMP was weighed and added to a stirring tank. 0.07 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as f0. 
     2. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as f1. 
     3. 0.4 g of Li 4 SiO 4  and 0.11 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.065 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.65 g of NMP was weighed and added to a stirring tank. 0.175 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as f2. 
     4. 0.63 g of Li 3 PO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as f3. 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                   
                 Prelithiation 
                   
                   
                 First-Cycle 
               
               
                 Battery 
                 material 
                 Binder 
                 Solvent 
                 Charge Capacity 
               
               
                 No. 
                 (%) 
                 (%) 
                 (%) 
                 (mAh/g) 
               
               
                   
               
             
            
               
                 f0 
                 38 
                 2 
                 60 
                 410 
               
               
                 f1 
                 25 
                 4 
                 71 
                 528 
               
               
                 f2 
                 16 
                 7 
                 77 
                 482 
               
               
                 f3 
                 25 
                 4 
                 71 
                 509 
               
               
                   
               
            
           
         
       
     
     Example 6 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6 , MoB 2 , Li 2 S, BP, and B were used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 0.53 g of Li 4 SiO 4 , 0.1 g of Li 3 PO 4 , 0.1 g of CaB 6 , 0.07 g of MoB 2 , and 0.1 g of C 6 H 6 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as I1. 
     2. 0.42 g of Li 4 SiO 4 , 0.38 g of MoB 2 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 12. 
     3. 0.52 g of Li 4 SiO 4 , 0.28 g of Li 2 S, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 13. 
     4. 0.59 g of Li 4 SiO 4 , 0.21 g of BP, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 14. 
     5. 0.7 g of Li 4 SiO 4 , 0.1 g of B, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as I5. 
     6. 0.7 g of Li 4 SiO 4 , 0.1 g of S, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 16. 
     7. 0.7 g of Li 4 SiO 4 , 0.1 g of NbN, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 17. 
     8. 0.7 g of Li 4 SiO 4 , 0.1 g of LiI, and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as 18. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Type of reductive 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 agent 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 I1 
                 CaB 6  + MoB 2   
                 517 
               
               
                   
                 I2 
                 MoB 2   
                 509 
               
               
                   
                 I3 
                 Li 2 S 
                 511 
               
               
                   
                 I4 
                 BP 
                 498 
               
               
                   
                 I5 
                 B 
                 518 
               
               
                   
                 I6 
                 S 
                 521 
               
               
                   
                 I7 
                 NbN 
                 501 
               
               
                   
                 I8 
                 LiI 
                 512 
               
               
                   
                   
               
            
           
         
       
     
     Example 7 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (CMC), and styrene-butadiene copolymer (SBR) with a solids content of 25% by weight were used as a binder; and 1-methyl-2-pyrrolidone (NMP) and high purity deionized water were used as a solvent to fabricate a positive electrode pole piece. 
     1. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of high purity deionized water was weighed and added to a stirring tank. 0.015 g of CMC was added to the high purity deionized water, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material and 0.075 g of SBR were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as g1. 
     2. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as g2. 
     3. 0.63 g of Li 3 PO 4  and 0.17 g of CaB 6  were subjected to ball milling to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as g3. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Solvent 
                   
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Type 
                 Binder Type 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 g1 
                 water 
                 CMC + SBR 
                 417 
               
               
                   
                 g2 
                 NMP 
                 PVDF 
                 528 
               
               
                   
                 g3 
                 NMP 
                 PVDF 
                 509 
               
               
                   
                   
               
            
           
         
       
     
     Example 8 
     In this example, LiFePO 4  was used as a positive electrode material; Li 4 SiO 4  was used as a lithium-containing compound; CaB 6  was used as a reductive agent; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent; Super-P, DK, and KB were used as a conductive additive to fabricate a positive electrode pole piece. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling after mixing to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material, and 0.4 g of g DK were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as h1. 
     2. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material, and 0.4 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as h2. 
     3. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material, and 0.4 g of KB were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as h3. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Conductive 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Carbon Type 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 h1 
                 DK 
                 169 
               
               
                   
                 h2 
                 Super-P 
                 175 
               
               
                   
                 h3 
                 KB 
                 170 
               
               
                   
                   
               
            
           
         
       
     
     Example 9 
     In this example, LiFePO 4  was used as a positive electrode material; Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compound; CaB 6  was used as a reductive agent; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent; Super-P was used as a conductive additive to fabricate a positive electrode pole piece. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were mixed and subjected to ball milling to control the particle size at 100 nm, as the prelithiation material A. 0.63 g of Li 3 PO 4  and 0.17 g of CaB 6  were mixed and subjected to ball milling to control the particle size at 100 nm, as the prelithiation material B. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material A, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as J1. 
     2. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material B, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as J2. 
     3. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material A, and 0.4 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as J3. 
     4. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material B, and 0.4 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as J4. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Conductive Additive 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Content (g) 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 J1 
                 0.1 
                 158 
               
               
                   
                 J2 
                 0.1 
                 156 
               
               
                   
                 J3 
                 0.4 
                 175 
               
               
                   
                 J4 
                 0.4 
                 169 
               
               
                   
                   
               
            
           
         
       
     
     Example 10 
     In this example, Li 4 SiO 4  and Li 3 PO 4  were used as a lithium-containing compounds; CaB 6  was used as a reductive agent; polyaniline, polypyrrole, titanium nitride, indium tin oxide, graphene, carbon nanotubes, and acetylene black were used as a conductive agent; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.08 g of polyaniline were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K1. 
     2. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.01 g of PPY were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K2. 
     3. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.49 g of titanium nitride were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K3. 
     4. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.12 g of indium tin oxid (ITO) were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K4. 
     5. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.227 g of graphene were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K5. 
     6. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.21 g of carbon nano tube (CNT) were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K6. 
     7. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.02 g of acetylene black were subjected to ball milling to control the particle size at 100 nm and mixed evenly. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the ball-milled prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as K7. 
     
       
         
           
               
               
               
             
               
                   
               
               
                   
                   
                 First-Cycle 
               
               
                 Battery 
                   
                 Charge Capacity 
               
               
                 No. 
                 Conductive agent 
                 (mAh/g) 
               
               
                   
               
             
            
               
                 K1 
                 Organic conductive polymer: polyaniline 
                 509 
               
               
                 K2 
                 Organic conductive polymer: polypyrrole 
                 525 
               
               
                 K3 
                 Inorganic conductive compound: titanium 
                 503 
               
               
                   
                 nitride 
               
               
                 K4 
                 Inorganic conductive compound: indium tin 
                 498 
               
               
                   
                 oxide 
               
               
                 K5 
                 Conductive carbon: graphene 
                 489 
               
               
                 K6 
                 Conductive carbon: carbon nanotube 
                 499 
               
               
                 K7 
                 Conductive carbon: acetylene black 
                 512 
               
               
                   
               
            
           
         
       
     
     Example 11 
     In this example, Li 4 SiO 4  was used as a lithium-containing compound; CaB 6  was used as a reductive agent; C 6 H 12 O 6 , C 2 H2, and petroleum asphalt were used as a conductive agent precursors; ethanol and ethylene glycol were used as hydrothermal solvents; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent to fabricate a positive electrode pole piece. 
     1. 0.63 g of Li 4 SiO 4 , 0.17 g of CaB 6 , and 0.1 g of C 6 H 12 O 6  were mixed and placed into a tube furnace. The mixture was fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as L1. 
     2. 0.2 g of petroleum asphalt was taken, and added to 20 ml of kerosene to be dissolved. The obtained solution was filtered multiple times. 0.63 g of Li 4 SiO 4 , and 0.17 g of CaB 6  were added and stirred uniformly. The solvent remaining in the mixture was evaporated. The mixture was placed in a tube furnace and subjected to a high-temperature carbonization treatment at 600° C. for 4 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as L2. 
     3. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were mixed and placed in a tube furnace. The mixture was fired at a high temperature of 450° C. under nitrogen gas for 2 h. The residual oxygen in the tube was removed. Then, the temperature was raised to 800° C. The mixture was fired at 800° C. under C 2 H 2  for 1 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as L3. 
     4. 0.1 g of C 6 H 12 O 6  was added to a mixed solution of 30 ml of ethanol and 20 ml of ethylene glycol. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were added to the above solution and stirred fully to mix evenly. The obtained solution was placed into a hydrothermal kettle and heated at 200° C. for 12 h. The thickness of the coated carbon layer was controlled at 30 nm. A prelithiation material was obtained by suction filtration and washing. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, the prelithiation material was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as L4. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                   
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Carbon Coating Process 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 L1 
                 High-temperature 
                 528 
               
               
                   
                   
                 decomposition C 6 H 12 O 6   
               
               
                   
                   
                 coating 
               
               
                   
                 L2 
                 Asphalt carbonization 
                 519 
               
               
                   
                   
                 coating 
               
               
                   
                 L3 
                 Gas phase C 2 H 2  coating 
                 521 
               
               
                   
                 L4 
                 Liquid-phase hydrothermal 
                 523 
               
               
                   
                   
                 coating 
               
               
                   
                   
               
            
           
         
       
     
     Example 12 
     In this example, LiFePO 4  was used as a positive electrode material; Li 4 SiO 4  was used as a lithium-containing compound; CaB 6  was used as a reductive agent; C 6 H 12 O 6  was used as a conductive agent precursor; polyvinylidene fluoride (PVDF) was used as a binder; 1-methyl-2-pyrrolidone (NMP) was used as a solvent; Super-P was used as a conductive additive of positive electrode to fabricate a positive electrode pole piece. 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were subjected to ball milling after mixing to control the particle size at 100 nm, mixed with 0.1 g of C 6 H 12 O 6 , and then placed in a tube furnace and fired at a high temperature of 700° C. under argon gas for 6 h. The thickness of the coated carbon layer was controlled at 30 nm to obtain a prelithiation material. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.76 g of LiFePO 4 , 0.04 g of prelithiation material, and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as M1. 
     2. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.8 g of the prelithiation material and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. A pre-prepared lithium iron phosphate pole piece was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as M2. 
     3. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.8 g of the prelithiation material and 0.1 g of Super-P were added to the stirring tank, and the resultant was stirred again until evenly dispersed. A pre-prepared separator was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried separator was punched to a suitable size. The side coated with the slurry was facing the active material side of the positive electrode pole piece to assemble a battery, which was recorded as M3. 
     
       
         
           
               
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 Use Method of Prelithiation 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Agent 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
                 M1 
                 Pre-mixed with the positive 
                 182 
               
               
                   
                   
                 electrode material 
               
               
                   
                 M2 
                 Coated on the surface of 
                 179 
               
               
                   
                   
                 positive electrode material 
               
               
                   
                 M3 
                 Coated on the surface of the 
                 181 
               
               
                   
                   
                 separator near the positive 
               
               
                   
                   
                 electrode side 
               
               
                   
                   
               
            
           
         
       
     
     Comparative Example 1 
     In this example, Li 3 PO 4  and Li 4 SiO 4  were used as a lithium-containing compounds; CaB 6 , Co 3 B 2 , and MoB 2  were used as a reductive agents; PVDF was used as a binder; NMP was used as a solvent to fabricate a positive electrode pole piece. 
     1. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.8 g of Li 3 PO 4  was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a0. 
     2. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.8 g of Li 4 SiO 4  was added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a1. 
     3. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.63 g of Li 3 PO 4  and 0.17 g of CaB 6  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a2. 
     4. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.63 g of Li 4 SiO 4  and 0.17 g of CaB 6  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a3. 
     5. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.42 g of Li 3 PO 4  and 0.38 g of MoB 2  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a4. 
     6. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.42 g of Li 4 SiO 4  and 0.38 g of MoB 2  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a5. 
     7. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.4 g of Li 3 PO 4  and 0.4 g of Co 3 B 2  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a6. 
     8. 2.5 g of NMP was weighed and added to a stirring tank. 0.1 g of PVDF was added to the NMP, and the resultant was stirred sufficiently until evenly dispersed. Then, 0.4 g of Li 4 SiO 4  and 0.4 g of Co 3 B 2  were added to the stirring tank, and the resultant was stirred again until evenly dispersed. An aluminum foil was evenly coated with the obtained slurry on the surface, and placed in a 55° C. oven to be dried for 6 h. The dried pole piece was punched into a disc with a diameter of 12 mm and transferred into a vacuum oven at 120° C. for 6 h. After the temperature dropped to room temperature, the pole piece was quickly transferred into a glove box filled with argon gas for storage. The resulting pole piece was recorded as a7. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Battery 
                 First-Cycle Charge 
               
               
                   
                 No. 
                 Capacity (mAh/g) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 a0 
                 2 
               
               
                   
                 a1 
                 3 
               
               
                   
                 a2 
                 11 
               
               
                   
                 a3 
                 12 
               
               
                   
                 a4 
                 5 
               
               
                   
                 a5 
                 7 
               
               
                   
                 a6 
                 5 
               
               
                   
                 a7 
                 6