Patent ID: 12261289

DETAILED DESCRIPTION OF THE INVENTION

Lithium-ion batteries are used in a variety of devices and electric vehicles due to the high energy and power densities lithium-ion batteries provide. As performance and power output for these devices and electric vehicles continuously improve, the demand for batteries with higher energy densities is rapidly growing. However, a few issues, including low capacity of the anode and limited charging speed, have become bottlenecks in the development of improved lithium-ion batteries.

Graphite, which is the most commonly used material for anode found in currently available lithium-ion batteries, has a relatively low capacity per unit volume and/or per unit weight, which limits the potential for increasing power capacity within a confined space of battery cells. Over the last several years, silicon, which exhibits about five to ten times the capacity per unit volume and/or per unit weight of graphite, has been used as an additive to graphite to improve the capacity of the anode in lithium ion batteries. However, silicon in these currently available lithium-ion batteries expands significantly when the batteries are charged, resulting in a need for extra volume in lithium-ion batteries and creating safety concerns caused by silicon expansion in the batteries. The present invention provides a solution to at least some of the above-described problems associated with currently available lithium-ion batteries. The disclosed solution is premised on a lithium-ion battery that include an anode comprising more than 30 wt. %, preferably more than 40 wt. %, and as high as 85 wt. %, silicon configured to exhibit limited or negligible volume expansions when during charging, thereby mitigating safety concerns and reducing the need for extra space to accommodate silicon expansion in lithium-ion batteries.

These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.

A. Lithium-Ion Battery

In embodiments of the invention, the lithium-ion battery comprises an anode, a cathode, and an electrolyte. The lithium ion battery can have significantly improved energy density compared to conventional lithium-ion batteries. With reference toFIG.1, a schematic diagram is shown for lithium-ion battery100.

According to embodiments of the invention, lithium-ion battery100includes anode101. Anode101can include anode active layer102comprising a silicon-based material. Non-limiting examples of the silicon-based material can include silicon, and silicon oxide (SiOx). In some instances, anode101comprises more than 30 wt. % of the silicon-based material. In some instances, anode101can include 30 to 85 wt. % of the silicon based material, and all ranges and values there between including ranges of 30 to 35 wt. %, 35 to 40 wt. %, 40 to 45 wt. %, 45 to 50 wt. %, 50 to 55 wt. %, 55 to 60 wt. %, 60 to 65 wt. %, 65 to 70 wt. %, 70 to 75 wt. %, 75 to 80 wt. %, and 80 to 85 wt. %. In some other aspects, anode101can include 75 to 85 wt. % of the silicon based material. The silicon based material of anode101can be configured to expand less than 50 vol. % when lithium-ion battery100is charging or charged. In some aspects, anode101including silicon may expand by 50 to 100 vol. % during entire charging process, depending on type(s) of silicon material used in anode101In embodiments of the invention, anode101comprising 30 to 85 wt. % of the silicon based material can be configured to have up to 10 times anode capacity compared to a graphite anode that does not include silicon, and up to 5 times the anode capacity compared to a graphite anode that has a silicon concentration of 30 wt. %. In some instances, anode101with 30 wt. % silicon can have up to 700 mAh/g capacity and anode101with 85 wt. % silicon can have 3400 mAh/g capacity, which is 10 times higher than the capacity of graphite.

In some aspects, the silicon based material of anode101can include silicon nanowires (as shown inFIG.2), silicon encapsulated in carbon (as shown inFIGS.4A and4B), a silicon and graphene blend, a silicon and elastic polymer mixture, silicon oxide, or any combination thereof. Silicon nanowires of anode101can further include a dopant deposited there over. Non-limiting examples of the dopant can include Tin, Germanium, Iron, Aluminum, Magnesium, or any combination thereof. The passivation agent may be in a form of nanoparticles. In some aspects, the silicon nanowires can have an average diameter in a range of 100 to 1000 nm and all ranges and values there between. In some instances, the silicon nanowires of anode101can be produced via etching, chemical vapor deposition, physical vapor deposition, precipitation, and/or ablation.

In some aspects, silicon based material of anode101can be configured in an “egg-yolk” configuration that follows an “egg-yolk” model as shown inFIGS.3A and3B. As shown inFIG.3A, the silicon based material having the “egg-yolk” configuration can have a cavity in an inner portion thereof. When lithium-ion battery100is charged, the cavity can shrink to accommodate the expansion of silicon while keep the overall volume substantially unchanged (e.g., the overall diameter R1of the silicon may be substantially the same when it is charged and discharged, as shown inFIGS.3A and3B). When lithium-ion battery100is discharged, the expansion of the silicon maybe substantially reversed and the cavity may recover substantially to its original size.

In some aspects, the silicon based material of anode101can include silicon encapsulated in carbon and the silicon encapsulated in carbon can include silicon particles (silicon bulk material) with an average diameter of 0.5 to 10 μm and all ranges and values there between including ranges of 0.5 to 1 μm, 1 to 1.5 μm, 1.5 to 2.0 μm, 2.0 to 2.5 μm, 2.5 to 3.0 μm, 3.0 to 3.5 μm, 3.5 to 4.0 μm, 4.0 to 4.5 μm, 4.5 to 5.0 μm, 5.0 to 5.5 μm, 5.5 to 6.0 μm, 6.0 to 6.5 μm, 6.5 to 7.0 μm, 7.0 to 7.5 μm, 7.5 to 8.0 μm, 8.0 to 8.5 μm, 8.5 to 9.0 μm, 9.0 to 9.5 μm, 9.5 to 10 μm. The silicon encapsulated in carbon can have an overall silicon to carbon weight ratio in a range of 0.1 to 4 and all ranges and values there between including ranges of 0.1 to 0.4, 0.4 to 0.8, 0.8 to 1.2, 1.2 to 1.6, 1.6 to 2.0, 2.0 to 2.4, 2.4 to 2.8, 2.8 to 3.2, 3.2 to 3.6, and 3.6 to 4.0. The carbon that encapsulates silicon can include graphite, graphene, carbon ash, or any combination thereof. In embodiments of the invention, the silicon encapsulated in carbon is produced via etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), precipitation, and ablation. As shown inFIGS.4A and4B, when lithium-ion battery100is charged, the graphene and/or polymer encapsulation layer may be configured to constrain expansion of silicon, resulting in mitigated silicon expansion in lithium-ion battery100. When lithium-ion battery100is discharged, the silicon particles and the graphene and/or polymer encapsulation layer may recover substantially to their original shapes.

In some aspects, the silicon based material of anode101can include a silicon-graphene blend, and the silicon-graphene blend can have a silicon to graphene weight ratio in a range of 0.1 to 4 and all ranges and values there between including ranges of 0.1 to 0.4, 0.4 to 0.7, 0.7 to 1, 1 to 1.3, 1.3 to 1.6, 1.6 to 1.9, 1.9 to 2.2, 2.2 to 2.5 to 2.8, 2.8 to 3.1, 3.1 to 3.4, 3.4 to 3.7, and 3.7 to 4.0. In some instances, the silicon-graphene blend may have an average particle size of 0.5 to 10 μm and all ranges and values there between including ranges of 0.5 to 1.0 μm, 1.0 to 2.0 μm, 2.0 to 3.0 μm, 3.0 to 4.0 μm, 4.0 to 5.0 μm, 5.0 to 6.0 μm, 6.0 to 7.0 μm, 7.0 to 8.0 μm, 8.0 to 9.0 μm, and 9.0 to 10 μm. The silicon particles of the silicon-graphene blend can be unimodal or bimodal in nature. The silicon particles of the silicon-graphene blend can be spherical, ellipsoid, cylindrical, orthogonal, or a combinations thereof.

In some aspects, the silicon based material of anode101can include a silicon and elastic polymer mixture having a silicon to polymer weight ratio in a range of 0.5 to 6 and all ranges and values there between including ranges of 0.5 to 1, 1 to 1.5, 1.5 to 2.0, 2.0 to 2.5, 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, and 5.5 to 6.0. Non-limiting examples for the elastic polymer can include polyacrylic acid, carboxymethyl cellulose, and combinations thereof. In some instances, the silicon and elastic polymer mixture is in powder form with spherical and/or ellipsoid particles. In embodiments of the invention, the silicon and elastic polymer mixture is produced via precipitation, mixing, baking, and/or any combination thereof. In embodiments of the invention, encapsulation of silicon particles may not change the shape of the silicon nanoparticles.

In embodiments of the invention, anode active layer102further includes a carbon based material. The carbon based material can be mixed with the silicon based material and/or coated over the silicon based material. The carbon-based material is configured to prevent expansion and/or improve conductivity of the silicon based material. Non-limiting examples of the carbon based material can include graphite, graphene, carbon ash, and combinations thereof. In some instances, the carbon-based material may be coated on the silicon via precipitation, mixing, baking, CVD, PVD, or any combination thereof. In some instances, coating of the carbon-based material over the silicon based material can have a thickness in a range of 5 to 1000 nm and all ranges and values there between including ranges of 5 to 10 nm, 10 to 20 nm, 20 to 30 nm, 30 to 40 nm, 40 to 50 nm, 50 to 60 nm, 60 to 70 nm, 70 to 80 nm, 80 to 90 nm, 90 to 100 nm, 100 to 200 nm, 200 to 300 nm, 300 to 400 nm, 400 to 500 nm, 500 to 600 nm, 600 to 700 nm, 700 to 800 nm, 800 to 900 nm, and 900 to 1000 nm. In embodiments of the invention, the silicon based material in anode101is further mixed with a secondary material. Non-limiting examples of the secondary material can include tin, antimony, germanium, and combinations thereof. The secondary material can be mixed with silicon at a silicon-to-secondary material weight ratio of 1:100 to 100:1 and all ranges and values there between.

In embodiments of the invention, anode101comprises first metal layer103. First metal layer103can include a metal sheet and/or a metal foil. In some instances, first metal layer103includes copper. In embodiments of the invention, anode active layer102comprising the silicon based material and/or the carbon based material is coated on one or both surfaces of first metal layer103. In some aspects, anode active layer102is coated on first metal layer103. The thickness of anode active layer102can be determined based on a target capacity for anode101. In some instances, the thickness of anode active layer102on first metal layer103can be in a range of 10 to 50 μm and all ranges and values there between including ranges of 10 to 12 μm, 12 to 14 μm, 14 to 16 μm, 16 to 18 μm, 18 to 20 μm, 20 to 22 μm, 22 to 24 μm, 24 to 26 μm, 26 to 28 μm, 28 to 30 μm, 30 to 32 μm, 32 to 34 μm, 34 to 36 μm, 36 to 38 μm, 38 to 40 μm, 40 to 42 μm, 42 to 44 μm, 44 to 46 μm, 46 to 48 μm, and 48 to 50 μm. In some aspects, anode active layer102is coated on first metal layer103via a process of doctor blade, slot die coater, comma coater, or any combinations thereof.

According to embodiments of the invention, lithium-ion battery100comprises cathode110. Cathode110, in embodiments of the invention, includes cathode active layer112comprising a lithium metal oxide. In some aspects, the lithium metal oxide of cathode110can have a formula of LiaNixAyBzO2where a≥1, x≥0.5, y+z=1−x. Non-limiting examples for A can include Manganese (Mn), Cobalt (Co), Aluminum (Al), and combinations thereof. Non-limiting examples for B can include Cobalt (Co), Manganese (Mg), Aluminum (Al), and combinations thereof. In some instances, the ratio of x:y:z can be 6:2:2, 8:1:1, or 9:0.5:0.5. It should be appreciated that the ratio of x:y:z is not limited to the aforementioned three examples, which have been provided for purposes of illustration, rather than by way of limitation. In some instances, cathode110includes Lithium, Nickel, Manganese, Cobalt oxide, or Lithium, Nickel, Cobalt, Aluminum oxide. In some other instances, cathode100includes Lithium Nickel oxide, or Lithium Manganese oxide.

In some aspects, the lithium metal oxide of cathode110is in a core-shell gradient structure with a concentration of Ni increasing from an outer shell to a core of the core-shell gradient structure, as shown inFIG.5. In some instances, as shown inFIG.5, a core portion of the core-shell structure of the lithium metal oxide of cathode110may include up to 80 wt. % Ni, and Ni concentration of a shell portion may decrease from up to about 80 wt. % in an inner layer of the shell portion to up to 33 wt. % in an outer layer of the shell portion. The core-shell gradient structure of the lithium metal oxide can be produced via a co-precipitation process. In some aspects, the lithium metal oxide may include dopants or a surface coating. Non-limiting examples for the dopants or the surface coating can include carbon, zirconium, aluminum, germanium, and combinations thereof.

In embodiments of the invention, cathode110includes second metal layer113and cathode active layer112is coated on one or both side of second metal layer113(It should be appreciated that second metal layer113refers to the metal layer used in cathode110, with the term “second” being used to differentiate the metal layer113of the cathode from the first metal layer of the anode. Thus the term “second” should not be understood to require the cathode110to include two metal layers). In some aspects, second metal layer113includes aluminum. Cathode active layer112can be coated on second metal layer113at a thickness of 20 to 100 micron (per side of second metal layer113) and all ranges and values there between. Cathode active layer112may be coated on second metal layer113via a comma coater, a slot die coater, or a doctor blade.

According to embodiments of the invention, lithium-ion battery100comprises an electrolyte disposed between anode101and cathode110. The electrolyte can be a non-flammable electrolyte. In some aspects, the non-flammable electrolyte comprises an ionic liquid. The ionic liquid can be protic or aprotic. The ionic liquid includes a cation and an anion. Non-limiting examples of the cation can include imidazolium, pyridinium, pyrrolidinium, piperidinium, and combinations thereof. Non-limiting examples of the anon can include bromides, chlorides, iodides, phosphates, BF4−, PF6−, TFSI−, FSI−, and combinations thereof.

In embodiments of the invention, in response to temperature increases, certain ionic compounds become liquids as a result of a thermal activation. A salt in this state is generally denoted as “molten salt” some of which remain liquid at ambient temperature even at a very low temperature. In some aspects, such molten salts are called as “ambient temperature ionic liquid” or “ionic liquid”. The ionic liquid of the electrolyte is configured to improve thermal stability and mitigating safety issues including, but not limited to, short-circuit, overcharge, crush leading to fire or explosion.

According to embodiments of the invention, lithium-ion battery100further includes separator120disposed between anode101and cathode110, and configured to prevent contact between anode101and cathode110. Separator120can include polyethylene (PE), and/or polypropylene (PP). Separator120may be coated with ceramics including aluminum oxide, and/or zirconium oxide configured to improve mechanical strength thereof. According to embodiments of the invention, lithium-ion battery100includes housing121configured to enclose anode101, cathode110, separator120, and the electrolyte. In some aspects, housing121can comprise polyethylene coated aluminum, nickel coated steel, aluminum, steel, or any combination thereof.

In embodiments of the invention, compared to the highest energy density of 550 to 600 Wh/L achieved by currently available lithium-ion batteries, lithium-ion battery100is configured to have an energy density in a range of 750 to 900 Wh/L and all ranges and values there between including ranges of 750 to 760 Wh/L, 760 to 770 Wh/L, 770 to 780 Wh/L, 780 to 790 Wh/L, 790 to 800 Wh/L, 800 to 810 Wh/L, 810 to 820 Wh/L, 820 to 830 Wh/L, 830 to 840 Wh/L, 840 to 850 Wh/L, 850 to 860 Wh/L, 860 to 870 Wh/L, 870 to 880 Wh/L, 880 to 890 Wh/L, and 890 to 900 Wh/L. With respect to energy per kilogram, lithium-ion battery100is configured to have an energy density of 250 to 450 Wh/kg and all ranges and values there between including ranges of 250 to 260 Wh/kg, 260 to 270 Wh/kg, 270 to 280 Wh/kg, 280 to 290 Wh/kg, 290 to 300 Wh/kg, 300 to 310 Wh/kg, 310 to 320 Wh/kg, 320 to 330 Wh/kg, 330 to 340 Wh/kg, 340 to 350 Wh/kg, 350 to 360 Wh/kg, 360 to 370 Wh/kg, 370 to 380 Wh/kg, and 380 to 390 Wh/kg, 390 to 400 Wh/kg, 400 to 410 Wh/kg, 410 to 420 Wh/kg, 420 to 430 Wh/kg, 430 to 440 Wh/kg, and 440 to 450 Wh/kg.

In embodiments of the invention, lithium-ion battery100can have an N:P ratio (i.e., the ratio of a negative electrode (anode101) capacity to a positive electrode (cathode110) capacity) in a range of 1.2 to 4 and all ranges and values there between including ranges of 1.2 to 1.6, 1.6 to 2.0, 2.0 to 2.4, 2.4 to 2.8, 2.8 to 3.2, 3.2 to 3.6, and 3.6 to 4.0. The high N:P ratio is configured to facilitate fast charging of lithium-ion battery100. In some aspects, fast charging of lithium-ion battery is conducted at a 4 to 10 C-rate, which corresponds to 15 to 6 minutes for charge, respectively and is up to 5 times faster than currently available batteries (e.g., currently available 21700 batteries). In some aspects, the high N:P ratio for lithium-ion battery is further configured to facilitate charging of lithium-ion battery100at a low temperature range of −20 to 0° C. with 50% charging rate of at 25° C.

AlthoughFIG.1shows a lithium-ion battery in a cylindrical cell format, it should be appreciated that lithium-ion battery100can be in various cell configurations including, but not limited to, cylindrical cell, a prismatic cell, and a pouch cell. In some instances, lithium-ion battery100can be configured in a cylindrical 21700 cell format, which has a diameter of about 21 mm and a length about 70 mm. In some aspects, lithium-ion battery100in cylindrical 21700 cell format can have a power capacity of 6 Ah. A higher limit of power capacity for currently available 21700 cell format is 4 Ah, and it would require significant research work for currently available 21700 cell to reach 5 Ah power capacity. Therefore, lithium-ion battery100of the invention provide significant technical achievement over currently available lithium-ion batteries.

The lithium-ion battery100in cylindrical 21700 cell format can have an Alternating Current Internal Resistance (ACIR) of less than 15 mOhms, and a Direct Current Internal Resistance (DCIR) of less than 25 mOhms. In some aspects, the cylindrical 21700 cell of lithium-ion battery100that has 6 Ah power capacity has a discharge rate capability of up to about 30 A continuous power and a pulse power capability of 100 A for 2 seconds. This represents significant improvement over currently available 21700 lithium-ion batteries, which are at best capable of providing 3 A continuous power and a pulse power of 8 A for 2 seconds.

In some instances, lithium-ion battery100can be configured in a cylindrical 18650 cell format, which has a diameter of about 18 mm and a length of about 65 mm. Lithium-ion battery of the cylindrical 18650 cell format can have an ACIR of less than 20 mOhms, and a DCIR of less than 30 mOhms. Although the characteristics of lithium-ion battery100in 21700 and 18650 cell formats have been described, it should be appreciated that embodiments may also be implemented in other cell formats to provide similar improvements although the specific numerical values of the continuous discharge rate, pulse discharge rate, power capacity (Ah), DCIR, and/or ACIR may change depending on the specific cell format. In some aspects, the cylindrical 18650 cell of lithium-ion battery100that has 4 Ah power capacity has a discharge rate capability of up to 5 C continuous without hitting voltage or temperature cut-off limit and a pulse power of up to 16 C without hitting any of the voltage or temperature cut-off limit.

In some aspects, lithium-ion battery100is configured to be used in a power tool. Non-limiting examples of the power tool can include a drill, a saw, a grass trimmer, a blower, and a sander. It should be appreciated that use of lithium-ion battery100is not so limited. Batteries configured to provide high power and high energy density in accordance with concepts herein may, for example, be utilized in powering such devices as portable smart devices, portable computational devices, electric vehicles, backup/uninterruptable power supplies, etc. In embodiments of the invention, lithium-ion battery100meets safety standards required for being used in the aforementioned devices. Non-limiting examples of the safety standards can include UN/DOT 38.3, 5thEdition, Amendment 1-Recommendations on the Transport of Dangerous Goods, IEC 62133-2:2017-Safety requirements for portable sealed secondary lithium cells, and for batteries made from them, for use in portable applications—Part2: Lithium systems, and UL 2054 2ndEdition—Household and Commercial Batteries.

B. Method of Producing Lithium-ion Battery

In embodiments of the invention, there are provided methods of producing aforementioned lithium-ion battery100, which can comprise anode101having 30 to 85 wt. % the silicon based material. According to embodiments of the invention, method200(as shown inFIG.6) for producing lithium-ion battery100can include, as shown in block201, producing the silicon based material of anode101lithium-ion battery100.

In some aspects, the silicon based material comprises silicon nanowires and the producing step at block201includes fabricating silicon nanowires via etching, chemical vapor deposition, physical vapor deposition, precipitation, and/or ablation. In some instances, surfaces of the silicon nanowires are further functionalized with a functional group. The functional group can include oxide, nitrides groups, or any combinations thereof. The silicon nanowires can further includes a dopant such as Magnesium (Mg).

In some aspects, the silicon based material comprises silicon encapsulated in carbon and the producing step at block201includes encapsulating silicon with carbon via thermal baking, physical vapor deposition, chemical vapor deposition. In embodiments of the invention, the silicon to be encapsulated at block201is produced via etching, chemical vapor deposition, physical vapor deposition, precipitation, or ablation.

In some aspects, the silicon based material comprises silicon mixed with elastic polymer and the producing step at block201includes mixing an elastic polymer with a silicon bulk material to form a substantially uniform mixture of silicon and the elastic polymer. In some instances, the elastic polymer includes etching, chemical vapor deposition, physical vapor deposition, precipitation, ablation. or any combination thereof. The mixing can include physical mixing, and heating.

According to embodiments of the invention, as shown in block202, method200includes producing the lithium metal oxide of cathode110. In some aspects, producing at block202can include solid state reaction between manganese oxide, nickel oxide, cobalt oxide and lithium carbonate. The solid state reaction for producing lithium metal oxide can be conducted at a temperature of 450 to 800° C. The produced lithium metal oxide can be in powder form.

According to embodiments of the invention, as shown in block203, method200includes mixing the silicon based material and/or the carbon based material of anode101with a conductive agent and a binder to form an anode mixture. As shown in block204, method200can include mixing the lithium metal oxide with a conductive binder to form a cathode mixture. The anode mixture and/or the cathode mixture can be in form of slurry. In some aspects, at block203, the anode mixture is formed with a weight ratio of the silicon based material to the conductive agent and binder in a range of 0.8 to 0.95. In some aspects, at block204, the cathode mixture is formed with a weight ratio of the lithium metal oxide to conductive agent and binder in a range of 0.88 to 0.97. In embodiments of the invention, anode mixture comprises no less than 30 wt. % silicon. Non-limiting examples of the conductive agent can include carbon black, acetylene black, ketjan black, Super P, carbon nanotubes, and combinations thereof. Non-limiting examples of the binder can include polyvinylidene fluoride (PVDF), carboxymethyl cellulose/styrene-butadiene rubber (CMC/SBR), polyacrylic acid (PAA), and combinations thereof.

According to embodiments of the invention, as shown in block205, method200includes coating anode active layer102on first metal layer103using the anode mixture. As shown in block206, method200can include coating cathode active layer112on second metal layer113using the cathode mixture. In some aspects, at block205, the coating step can include spreading anode mixture on first metal layer103. At block206, the coating step can include spreading cathode mixture on second metal layer113. The coating step at block205can further include compressing the anode mixture on first metal layer103. At block206, the coating step can include compressing the cathode mixture on second metal layer113to adjust thickness thereof. The coating steps at blocks205and206can further include drying the anode mixture on first metal layer103and drying the cathode mixture on second metal layer113after the compressing step, respectively. The coating steps at blocks205and206can further still include cutting the dried anode mixture along with first metal layer103and cutting the dried cathode mixture along with second metal layer113into desired shape and/or size, thereby forming anode101and cathode110, respectively. Anode101produced at block205can include 30 to 85 wt. % silicon, preferably 40 to 85 wt. % silicon and all ranges and values there between including ranges of 40 to 45 wt. %, 45 to 50 wt. %, 50 to 55 wt. %, 55 to 60 wt. %, 60 to 65 wt. %, 65 to 70 wt. %, 70 to 75 wt. %, 75 to 80 wt. %, and 80 to 85 wt. %.

According to embodiments of the invention, as shown in block207, method200includes assembling anode101, cathode110, separator120, in housing121to form an unfinished cell. In some aspects, the assembling step at block207includes laminating anode101, separator120, cathode110to form an electrode structure, connecting anode101and cathode110of the electrode structure to corresponding terminals. In some aspects, safety devices and/or vents may be connected and/or disposed on the electrode structure and/or terminals to form an subassembly. Assembling at block207can include inserting the subassembly into housing121, and sealing housing121. In some aspects, at least one opening is left on housing121after it is sealed.

According to embodiments of the invention, as shown in block208, method200includes adding the electrolyte into sealed housing121to form lithium-ion battery100. In some aspects, the adding electrolyte step at block206can include drying sealed housing121obtained from block205in vacuum, filling electrolyte into dried sealed housing121through the at least one opening in vacuum, and sealing the at least one opening of housing121to form lithium-ion battery100.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification.