Patent Publication Number: US-2010124702-A1

Title: High Energy Composite Cathodes for Lithium Ion Batteries

Description:
GOVERNMENT RIGHTS 
     This invention was made with government support under Contract No. F33615-03-C-2369 awarded by the United States Air Force. The government may have certain rights in the invention. 
    
    
     FIELD OF THE INVENTION 
     In general, the invention relates to materials for use as battery cathodes. In particular, the invention relates to composite materials and methods of making and using the composite materials in batteries. 
     BACKGROUND OF THE INVENTION 
     Lithium ion batteries are a type of rechargeable battery commonly used in consumer electronics. They are currently one of the most popular types of battery, with one of the best energy-to-weight ratios, minimal memory effect and a slow loss of charge when not in use. Lithium ion batteries are significantly lighter than equivalents in other chemistries such as, for example, lead-acid, nickel-metal hydride, and nickel cadmium. 
     However, lithium ion batteries show limited applications in certain space and terrestrial applications due to the limited performance at the cathode. This limited performance is due to the limited specific energies and capacities of the cathode material. A variety of metals, metal oxides and metal complexes can be used as cathode materials for lithium ion batteries. Vanadium pentoxide (V 2 O 5 ), in particular, exhibits a high theoretical capacity of 600 Ah/kg and theoretical energy of 1600 Wh/kg because of its ability to intercalate four electrons per formula unit. However, it has not yet been implemented in commercial rechargeable batteries because its available capacity is limited to two electrons per formula unit and its reversible capacity to one electron per formula unit. Without wishing to be bound by theory, concentration polarization driven by poor electronic conductivity and irreversible phase changes upon intercalation past LiV 2 O 5  may be the reasons for this drawback. 
     SUMMARY OF THE INVENTION 
     The invention features a composite material including a plurality of particulates for use in battery cathodes. The invention also features methods of making and using the composite material. 
     In one aspect, the invention features a battery cathode including carbon particulates, micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) (PPPS), and a polymer binder. The carbon particulates and the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) are disposed within the polymer binder. 
     In another aspect, the invention features a battery cathode including carbon particulates, micron-sized particles of vanadium pentoxide, a conducting polymer and a polymer binder. The micron-sized particles of vanadium pentoxide are modified with the conducting polymer to form a bi-layer ribbon structure having a bi-layer spacing of about 13.5 to about 15 Angstroms. The carbon particulates and the micron-sized particles of vanadium pentoxide modified with the conducting polymer are disposed within the polymer binder. 
     In yet another aspect, the invention features a method of making a cathode composite by forming a xerogel of poly(pyrrole propanesulphonate) modified vanadium pentoxide. The xerogel is processed to form micron-sized particles of poly(pyrrole propanesulphonate) modified vanadium pentoxide. The micron-sized particles of poly(pyrrole propanesulphonate) modified vanadium pentoxide are mixed with carbon particulates and a polymer binder to form the cathode composite. 
     In another aspect, the invention features a method of making a battery cathode. An adhesion layer is applied to an aluminum foil current collector. A slurry is deposited on the adhesion layer. The slurry includes particulates of carbon, micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate), and a polymer binder. The deposited slurry is dried to form the battery cathode. 
     In yet another aspect, the invention features a battery including a cathode, an anode, a porous separator, and an electrolytic solution. The cathode includes a layer of composite material formed from (i) particulates of carbon, (ii) micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate), and (iii) a polymer binder. The anode includes lithium ions. The porous separator and the electrolytic solution are disposed between the cathode and the anode. 
     In another aspect, the invention features a method of making composite particulates. A xerogel of poly(pyrrole propanesulphonate) modified vanadium pentoxide, is formed. The xerogel is milled to form micron-sized particulates of poly(pyrrole propanesulphonate) modified vanadium pentoxide. 
     In other examples, any of the aspects above can include one or more of the following features. The micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include at most 400 ppm of poly(pyrrole propanesulphonate). In certain embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include between 150 ppm and 300 ppm poly(pyrrole propanesulphonate). In certain embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can make up about 75 weight percent to 90 weight percent of the total weight. 
     The carbon particulates can make up about 7 weight percent to 15 weight percent of the total weight. In certain embodiments, the polymer binder can make up about 3 weight percent to 10 weight percent of the total weight. 
     In some embodiments, the carbon particulates can be acetylene black particles, graphite flakes, or combinations thereof. The polymer binder can be polyvinylidene fluoride. In certain embodiments, the composite material can be included in a slurry. 
     In some embodiments, the xerogel of poly(pyrrole propanesulphonate) modified vanadium pentoxide can be formed by mixing vanadium(V)oxytrialkoxides and water to form vanadium pentoxide hydrogel having a bi-layer ribbon structure with a bi-layer spacing of about 9 Angstroms to about 13 Angstroms. Poly(pyrrole propanesulphonate) in monomer form can be added to the water used to form the vanadium pentoxide hydrogel. Triisopropoxy vanadium oxide can be introduced dropwise into the water solution, and excess water can be removed. 
     In certain embodiments, the xerogel can include at most 400 ppm of poly(pyrrole propanesulphonate). In some embodiments, the xerogel can be processed by milling. An attritor mill can be used to produce particles having an average size of about 5 to about 10 microns. 
     In certain embodiments, the adhesion layer can include a mixture of graphite flakes and a hydrophilic binder. The adhesion layer can have a thickness of about 10 microns to about 12 microns. In some embodiments, the slurry can be deposited using draw casting. The slurry can be dried to form a layer having a thickness of about 5 microns to about 500 microns. 
     In some embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can have an average size of about 5 to 10 microns. The micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include about 400 ppm of poly(pyrrole propanesulphonate). The micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include between about 75 weight percent and about 90 weight percent of the composite material. The carbon particulates can include between about 7 weight percent and about 15 weight percent of the composite material. The polymer binder can include between about 3 weight percent and 10 weight percent of the composite material. 
     The xerogel of poly(pyrrole propanesulphonate) modified vanadium pentoxide can be formed by mixing vanadium(V)oxytrialkoxides and water to the water used to form the vanadium pentoxide hydrogel. Poly(pyrrole propanesulphonate) in monomer form can be added to the hydrogel to form a solution. Triisopropoxy vanadium oxide can be introduced dropwise into the water solution. Excess water can be removed to form the xerogel. The vanadium pentoxide hydrogel can have a bi-layer ribbon structure with a bi-layer spacing of about 9 Angstroms to about 13 Angstroms. An attritor mill can be used to produce particulates of the xerogel. The particulates can have an average size of about 5 to about 10 microns. 
     A composite V 2 O 5  cathode material can improve rechargeable lithium ion battery performance. A V 2 O 5 /PPPS material can be inherently more resistive than a typical rechargeable cell based on LiCoO 2 . A high performance cathode can enhance the applicability of lithium ion batteries in certain space and terrestrial applications. 
     The details of one or more examples are set forth in the accompanying drawings and description. Further features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The advantages of the invention described above, together with further advantages, may be better understood by referring to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. 
         FIG. 1  shows an exemplary high energy lithium ion battery 
         FIG. 2  shows an exemplary battery cathode. 
         FIG. 3  shows an example of the V 2 O 5 /conducting polymer interaction. 
         FIG. 4  shows the relative resistance of V 2 O 5  as a function of oxidation state. 
         FIG. 5  shows the  1 H NMR of PPPS monomer, 3-(pyrrol-1-yl)-propanesulphonate. 
         FIG. 6  shows the  13 C NMR of PPPS monomer, 3-(pyrrol-1-yl)-propanesulphonate. 
         FIG. 7  shows the  1 H-NMR spectrum of EDOPPS. 
         FIG. 8  shows the mass spectrum of EDOPPS. 
         FIG. 9  shows the FESEM image of the milled composite cathode material. 
         FIG. 10  shows the FESEM Image of a prepared cathode at 500 and 5000× magnification. 
         FIG. 11  shows the XRD data for V 2 O 5 /PPPS composites. 
         FIG. 12  shows the XRD data for 3 loadings of PEDOPPS in V 2 O 5 . The inset shows angles from 2° to 6° 2Θ. 
         FIGS. 13   a - 13   c  show the electron diffraction patterns and indexing data for the V 2 O 5  samples. 
         FIG. 14  shows the particle size distribution for the milled composite cathode material—d 10 =0.47 μm, d 50 =1.6 μm, d 90 =8 μm. 
         FIG. 15  shows the discharge curves at the 3rd cycle for three cells including V 2 O 5  composite cathode and lithium metal anode at three discharge rates. 
         FIG. 16  shows the discharge performance of two cells at the C/8 rate—V 2 O 5  vs. lithium. 
         FIG. 17  shows the discharge interrupt testing showing the difference in polarization between a commercial 18650 lithium-ion and a V 2 O 5 /PPPS battery. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a battery  10  including a cathode  12  separated from an anode  14  by a porous separator  16 . In one embodiment, the battery  10  is a high energy lithium ion battery. The anode  14  can be a lithium ion anode. The cathode  12  includes a terminal  18 , and the anode  14  includes a terminal  19 . The battery  10  includes an electrolytic solution  20  capable of passing through the porous separator  16 . The battery  10  include a casing  22 . The cathode  12  can include a composite material  24 . 
       FIG. 2  shows an enlarged view of the composite material  24  including micron-sized particles  26  of vanadium pentoxide modified with a conducting polymer, carbon particulates  28 , and a polymer binder  30 . The cathode  12  can be prepared by coating an aluminum foil current collector with an adhesion layer. A slurry of composite material  24  can be deposited over the adhesion layer. In general, the slurry can be a mixture of the composite material  24  and a suitable solvent, for example, N-methylpyrrolidone (NMP) an electronic conductor such as acetylene black and a polymeric binder. 
     The composite material  24  can be prepared by forming a gel of vanadium pentoxide modified with a conducting polymer. A monomer of a conducting material such as pyrrole propanesulphonate (PPS) can be mixed with a vanadium trialkoxide and water. The resulting hydrolysis and polymerization reactions can lead to the formation of a gel in which the vanadium oxide self-assembles into a bi-layer ribbon-like structure and the PPS polymerizes to the corresponding conducting polymer poly(pyrrole propanesulphonate) (PPPS). 
     As shown in  FIG. 3 , conducting polymer chains  32  can grow between bi-layers  34  to form an interpenetrating polymer network having intimate contact with the bi-layers  34 . In some embodiments, the gel can have a significant amount of water (e.g., as much as 99% by weight) entrapped in the bi-layers and is called a hydrogel. In certain embodiments, the gel does not have a significant amount of water and is called a xerogel. The hydrogel can be further dried to form the corresponding xerogel. The xerogel can be milled to form micron-sized particles which can be mixed with carbon particulates and/or polymer binders. 
     Vanadium pentoxide (V 2 O 5 ) has a high theoretical capacity of 600 Ah/kg and theoretical energy of 1600 Wh/kg. This is because of its unique ability to intercalate four electrons per formula unit. In general, it is a poor conductor in which the thermally activated electron transport occurs through the hopping of vanadium&#39;s d electrons between V 4+  and V 5+  centers and between V 3+  and V 4+  centers on further reduction.  FIG. 4  represents this concept graphically. 
     A variety of carbon particulates can be used in the composite material  24 . For example, elemental carbon black, acetylene black, or graphite flakes can be used. A variety of polymer binders are commercially available and can be used in the composite material  24 . For example, polyvinylidene fluoride (PVF) can be used. 
     The anode  14  can be prepared by using commercially available graphite anode material for example, material available from Lithion Inc., Connecticut. The anode  14  can be electrochemically lithiated. In certain embodiments, a graphite based material can be coated, covered or electroplated with lithium metal. 
     The porous separator  16  can be prepared using commercially available material, for example, Celgard® 2400 available from Celgard LLC, North Carolina. In certain embodiments, a polymer membrane such as, for example, polyethylene membrane can be used. 
     The electrolytic solution  20  can be prepared using commercially available material, for example, an electrolytic solution available from Sigma-Aldrich, Missouri. In some embodiments, solid lithium salts such as, for example, LiPF 6 , LiBF 4 , or LiClO 4  can be used. In certain embodiments, commercially available organic liquids such as for example ether can be used. In various embodiments, solid materials such as organic carbonates, for example, ethylene carbonate, and dimethyl carbonate can be used. In some embodiments, mixtures of solids and liquids in different proportions can be used. 
     The outer shell casing  22  of the battery  10 , can be prepared using commercially available material. In some embodiments, the casing can be a polymer. In certain embodiments, the casing can be made of metal alloys, such as for example, stainless steel. 
     Preparation of Conducting Polymers 
     The synthesis of included polymers can be characterized by the preparation of the corresponding monomers. The syntheses described below are for illustration and should not be construed as limiting the scope of the invention. 
     Pyrrole Propanesulphonate (PPS) Synthesis 
     Scheme 1 depicts a synthesis of PPS. Freshly distilled pyrrole (1.3 mL) in DMSO (18 mL) at 60° C. can be added to a suspension of NaH (60% in mineral oil) (0.8 g) in dry DMSO (10 mL) under constant stirring and an argon atmosphere over ˜1 hour. 1,3-propane sultone (2.45 g) can be melted with a heat gun and added dropwise to the reaction mixture. Following the addition, the solution can be allowed to stir at 60° C. for an additional 2 hours. The reaction mixture can be then poured into acetone (300 mL), and CHCl 3  can be added causing a white solid to precipitate. The solid can be filtered, washed with hot THF (3×100 mL), washed with hexanes (100 mL), and dried under vacuum at room temperature to give 2.7 g (64% yield) of an off-white solid. 
     
       
         
         
             
             
         
       
     
       FIG. 5  shows a proton NMR of PPS.  1 H NMR (DMSO-d 6 , 300 MHz): δ 1.92-1.97 (2H, m), 2.33 (2H, t, J=7 Hz), 3.95 (2H, t, J=7 Hz), 5.96 (2H, t, J=2 Hz), 6.71 (2H, t, J=2 Hz).  FIG. 6  shows a carbon NMR of PPS.  13 C NMR (DMSO-d 6 , 75 MHz): δ 27.77, 47.67, 48.35, 107.37, 120.52. 
     Ethylenedioxypyrrole Propanesulphonate (EDOPPS) Synthesis 
     Sodium 3-(3,4-Ethylenedioxypyrrol-1-yl)propanesulfonate (EDOPPS) can be prepared using nine synthetic steps. 
     Bis-methoxycarbonylmethyl-ammonium; chloride 1 
     
       
         
         
             
             
         
       
     
     (Methoxycarbonylmethyl-amino)-acetic acid methyl ester 2 
     
       
         
         
             
             
         
       
     
     (Benzyl-methoxycarbonylmethyl-amino)-acetic acid methyl ester 3 
     
       
         
         
             
             
         
       
     
     1-Benzyl-3,4-dihydroxy-1H-pyrrole-2,5-dicarboxylic acid dimethyl ester 4 
     
       
         
         
             
             
         
       
     
     6-Benzyl-2,3-dihydro-6H-[1,4]dioxino[2,3-c]pyrrole-5,7-dicarboxylic acid dimethyl ester 5 
     
       
         
         
             
             
         
       
     
     2,3-Dihydro-6H-[1,4]dioxino[2,3-c]pyrrole-5,7-dicarboxylic acid dimethyl ester 6 
     
       
         
         
             
             
         
       
     
     2,3-Dihydro-6H-[1,4]dioxino[2,3-c]pyrrole-5,7-dicarboxylic acid 7 
     
       
         
         
             
             
         
       
     
     2,3-Dihydro-6H-[1,4]dioxino[2,3-c]pyrrole 8 (EDOP) 
     
       
         
         
             
             
         
       
     
     Sodium 3-(3,4-Ethylenedioxypyrrol-1-yl)propanesulfonate 9 
     
       
         
         
             
             
         
       
     
     The N-alkylation of EDOP with a pendant (propanesulfonate) can be achieved by reacting EDOP with propanesultone and NaH in THF at 0° C. By adapting the procedure used for the preparation of ProDOT-PS, it is possible to isolate EDOPPS 9 in 50% yield (98% purity by LC-MS).  FIGS. 7 and 8  highlight the NMR data and mass spectrum of compound 9 respectively. 
     Monomers of other conducting polymers known in the art such as poly(acetylene)s, poly(pyrrole)s, poly(thiophene)s, poly(aniline)s, poly(fluorene)s, poly(3-hexylthiophene), polynaphthalenes, poly(p-phenylene sulfide), and poly(para-phenylene vinylene)s can be prepared and characterized using the above synthetic protocol for the purposes of this invention. 
     Preparation of Hydrogel and Xerogel 
     A sol-gel method can be used to prepare a hydrogel and xerogel of the cathode material. Vanadium oxytrialkoxides can be mixed with water and made to undergo a hydrolysis reaction. Typically, a round bottom flask can be charged with water. To avoid pre-polymerization of introduced conducting polymer monomers, dissolved oxygen can be purged from the water in the flask by bubbling argon. The monomer for the desired conducting polymer can be introduced as a solution by syringe through a rubber septum. Usually, about 50-200 g of a vanadium trialkoxide such as triisopropoxy vanadium oxide (TIVO) per liter of water can be added dropwise by syringe through the rubber septum over the course of 15 minutes to 3 hours. The solution can be vigorously stirred. The resulting solution can be allowed to rest for 12-48 hours in which time gelation of V 2 O 5  occurs. Excess water can be removed by rotary evaporation to form a viscous gel. This resulting gel, known as hydrogel, can be allowed to further dry on the bench top for about 12-48 hours. Additional drying at about 50-250° C. can be done to form the corresponding dehydrated gel known as xerogel. 
     In some embodiments, the hydrogel can have a bi-layer ribbon structure with a bi-layer spacing of about 2 Angstroms to about 60 Angstroms. In certain embodiments, the hydrogel can have a bi-layer ribbon structure with a bi-layer spacing of about 5 Angstroms to about 30 Angstroms. In various embodiments, the hydrogel can have a bi-layer ribbon structure with a bi-layer spacing of about 9 Angstroms to about 13 Angstroms. 
     The xerogel can include significantly less water than the hydrogel. For example, the water content can be less than about 3.0 parts H 2 O per part V 2 O 5  Gels can be dried under ambient temperature conditions such as at room temperature and at atmospheric pressure. The temperature and pressure can be varied to get the desired amount of water in the interlayer space and thus a desired thickness of the bi-layers. In one embodiment, a xerogel can have a d-spacing of about 10 to 15 Å. In one embodiment, the d-spacing is about 11.5 to 13 Å. X-ray diffraction can be used to measure the d-spacing. In general, the xerogel can be described by the formula V 2 O 5 .xH 2 O, where x can have a value of about 0.8 to 3. More rigorous drying of the xerogel under mild vacuum at about 10 to 10 −4  torr (e.g., 10 −2  torr) and a temperature of about 150 to 350° C. (e.g., 250° C.) can yield a spacing of about 8.4 to 8.95 Å (e.g., 8.75 Å) and the formula V 2 O 5 .0.3H 2 O. 
     In some embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include 50-1000 ppm of poly(pyrrole propanesulphonate). In certain embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include 100-800 ppm of poly(pyrrole propanesulphonate). In various embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include 150-300 ppm of poly(pyrrole propanesulphonate). In some embodiments, the micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) can include at most 400 ppm of poly(pyrrole propanesulphonate). 
     In certain embodiments, the polymer can be in its conducting state from 4 to 1.5 V vs. Li/Li + . This is the range in which V 2 O 5  is active. Polymers such as, poly(ethylene dioxythiophene) (PEDOT) and poly(N-propane sulfonic acid aniline) (PSPAN), can both conduct below 3.0V vs. Li/Li +  and can increase performance during the first two reductions of V 2 O 5  (to the uniform V 4+  state). Poly(aniline) can be conductive down to 3.25 V vs. Li/Li + . Derivatives of PEDOP and PPPS can be used. 
     In some embodiments, the micron-sized particles of vanadium pentoxide modified with a conducting polymer such as poly(pyrrole propanesulphonate) can form a bi-layer ribbon structure having a bi-layer spacing of about 3 to about 50 Angstroms. In certain embodiments, the micron-sized particles of vanadium pentoxide modified with a conducting polymer such as poly(pyrrole propanesulphonate) can form a bi-layer ribbon structure having a bi-layer spacing of about 8 to about 30 Angstroms. In various embodiments, the micron-sized particles of vanadium pentoxide modified with a conducting polymer such as poly(pyrrole propanesulphonate) can form a bi-layer ribbon structure having a bi-layer spacing of about 13.5 to about 15 Angstroms. 
     Preparation and Characterization of Composite Material 
     V 2 O 5 /conducting polymer composite materials can be synthesized by using a sol-gel chemical method. A combination of vanadium(V)oxytrialkoxides and water can result in the hydrolysis of the alkoxy ligands and condensation of the vanadium(V)oxytrihydroxo species to V 2 O 5  moieties referred to as hydrogels. V 2 O 5  hydrogels can include ribbon like bi-layers of V 2 O 5  that can be 100 nm wide, and/or 1000 nm long. The bi-layers can be separated by inter-layer distance of 5 to 11 nanometers. This synthetic approach can provide the ability to cause species to be included between the two halves of the V 2 O 5  bi-layer thereby promoting molecular level mixing in a nano-structured material. 
     When the included species is a monomer that can be oxidatively polymerized, V 2 O 5  can act as an electron acceptor and can cause oxidative polymerization of the material. Conducting polymer chains can grow between the V 2 O 5  bi-layers to form an interpenetrating polymer network having intimate contact with the V 2 O 5  active material. The composites such as PPPS/V 2 O 5  and PEDOPPS/V 2 O 5  can be characterized by X-ray diffraction, conductivity measurement and/or electron diffraction techniques. The X-ray diffraction studies can be used to detect and measure any structural changes that can occur upon formation of the composite material. Finally, electron diffraction techniques can be used to detect and measure any molecular level changes brought on by polymer inclusion in the V 2 O 5  matrix. Additional characterization by infrared spectroscopy or UV-visible spectroscopy can be employed when necessary. 
     Preparation of the Battery Cathode 
     The composite material can be milled to form micron sized particulates. A slurry including the particulates can be formed. An aluminum foil can be treated with an adhesion layer and the slurry. 
     (i) V 2 O 5  Composite Particulate Formation 
     The xerogel including the V 2 O 5 /conducting polymer composite materials can be milled to micron sized particulates using an attritor mill. Attritor milling is a ball milling technique in which the grinding media can be stirred through the target material rather than the shaking action of typical ball mills. An attritor mill can have a central rotating shaft, equipped with several horizontal arms that exert sufficient stirring action to force the grinding media to tumble randomly throughout the whole tank volume, causing irregular movement instead of group movement. The result can be a grinding process that imparts shear and impact forces to the target material (rather than shear forces alone as in ball milling). This action can promote the formation of spherical particulates. The technique can be suited for producing particulate in the sub 10 micron size range. 
     In some embodiments, milling is used to produce particles having an average size of about 1 to about 100 microns. In certain embodiments, milling is used to produce particles having an average size of about 3 to about 30 microns. In various embodiments, milling is used to produce particles having an average size of about 5 to about 10 microns. 
     As used herein, micro-sized particles or micron-sized particulates can be defined as the majority of the particles having a dimension between about 0.1 microns and about 100 microns. Thus, while a majority (e.g., about 85 weight percent) of the particles have a dimension between about 0.1 microns and about 100 microns, some of the particles can be outside of this range. For example, while most of the particles as determined by weight percent will have a dimension between about 0.1 microns and about 100 microns, a small portion (e.g., less than about 10 weight percent of the particles) can be smaller than micron-sized and a small portion (e.g., less than 10 weight percent of the particles) can be larger than micron-sized. 
       FIG. 9  shows FESEM images of a milled cathode material. The particle size distribution can be comparable to mortar and pestle ground material with the largest particles being less than 10 μm and a median particle size of approximately 5 μm. 
     (ii) Slurry Formation 
     Slurry formation can be the next step in the preparation of the battery cathode. Carbon particulates such as elemental carbon black, acetylene black or graphite flakes can be mixed with the micron sized particulates of the xerogel. In some embodiments, a combination of the above mentioned carbon particulates can be used. A polymer binder such as polyvinylidene fluoride (PVDF) can be added along with a solvent such as N-methyl-2-pyrrolidone (NMP). A homogeneous slurry of the ingredients can be obtained by mixing processes such as high speed shear mixing or ultrasonic mixing or both. The slurry can be optionally subjected to a vacuum to remove any bubbles formed during the mixing step. 
     In some embodiments, drying the slurry can form a layer having a thickness of about 1 microns to about 1500 microns. In certain embodiments, drying the slurry can form a layer having a thickness of about 3 microns to about 1000 microns. In various embodiments, drying the slurry can form a layer having a thickness of about 5 microns to about 500 microns. 
     (iii) Electrode Preparation 
     Standard methods to prepare cathodes of lithium ion batteries can be used for the composite electrode preparation. A commercially available aluminum foil current collector can be treated with an adhesion layer. A cathode slurry can be applied. Drying and optional calendaring of the slurry can result in the desired cathode. 
     (iv) Adhesion Layer 
     The adhesion layer can include a hydrophilic binder, water and high conductivity graphite flakes. The desired thickness or consistency of the adhesion layer can be controlled by the amounts of water and solids. The adhesion layer can be applied to the aluminum foil current collector. An automatic drawdown doctor blade apparatus can be used to apply the adhesion layer. The layer can be dried under heat and/or reduced pressure. 
     In some embodiments, the adhesion layer has about a 3 microns to about 50 microns thickness. In certain embodiments, the adhesion layer has about a 6 microns to about 20 microns thickness. In various embodiments, the adhesion layer has about a 10 microns to about 12 microns thickness. 
     (v) Slurry Deposition 
     The slurry can be deposited by draw casting, which involves an automatic drawdown doctor blade machine. Such a device can ensure repeatable constant velocity of the doctor blade. 
     An aluminum foil can be fixed on the stage of the auto-drawdown machine and cleaned with methanol. The doctor blade assembly can be placed on the right side of the drawdown machine and excess cathode slurry can be placed in front of the doctor blade assembly. Electrodes can be cast at a drawdown velocity of 2 inches per second. The electrodes can be dried at 100° C. for 1 hour and then for 24 hours at 110° C. under vacuum to remove residual solvent. An SEM image of a typical draw cast electrode is shown in  FIG. 10 . 
     In some embodiments, the battery cathode can include micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) between about 50 weight percent and about 99 weight percent of the total weight. In certain embodiments, the battery cathode can include micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) between about 60 weight percent and about 94 weight percent of the total weight. In various embodiments, the battery cathode can include micron-sized particles of vanadium pentoxide modified with poly(pyrrole propanesulphonate) between about 75 weight percent and about 90 weight percent of the total weight. 
     In some embodiments, the battery cathode can include carbon particulates between about 1 weight percent and about 45 weight percent of the total weight. In certain embodiments, the battery cathode can include carbon particulates between about 3 weight percent and about 30 weight percent of the total weight. In various embodiments, the battery cathode can include carbon particulates between about 7 weight percent and about 15 weight percent of the total weight. 
     In some embodiments, the battery cathode can include polymer binder between about 1 weight percent and about 30 weight percent of the total weight. In certain embodiments, the battery cathode can include polymer binder between about 2 weight percent and about 20 weight percent of the total weight. In various embodiments, the battery cathode can include polymer binder between about 3 weight percent and about 10 weight percent of the total weight. 
     Preparation of the Battery Anode 
     A commercially available graphite anode material can be used. It can be electrochemically lithiated prior to assembly of the battery. For example, full size electrodes (44 cm 2 ) can be layered with Celgard 2400 separator and lithium metal foil for lithium intercalation. A constant current can be applied and voltage can be monitored to a cut off of 0.01 V vs. lithium to avoid damaging the graphite structure by over lithiation. The anodes can have a capacity in excess of 320 mAh/g. 
     Battery Design 
     A design model that works well with typical prismatic cell designs can be developed. A battery design spreadsheet can be used to evaluate the effect of material and electrode design changes on battery performance characteristics and can be implemented in this invention. The spreadsheet can be designed to calculate performance characteristics of prismatic lithium cells with a stacked electrode configuration. The spreadsheet can allow the user to input a variety of battery, material and electrode design properties. 
     The following examples illustrate further the invention but, of course, should not be construed in any way of limiting its scope. 
     Preparation of Hydrogel and Xerogel 
     A 3 liter round bottom flask can be charged with 1 liter of water. Dissolved oxygen can be purged from the water in the flask by bubbling argon. After purging, the monomer for the desired conducting polymer can be introduced as a solution by syringe through a rubber septum. 100 g of triisopropoxy vanadium oxide (TIVO) can be added dropwise by syringe through the rubber septum over the course of 1 hour while the solution can be vigorously stirred. The resulting solution can be allowed to rest for 24 hours in which time gelation of V 2 O 5  occurred. Excess water can be removed by rotary evaporation to yield a viscous gel. The hydrogel can be allowed to further dry on the bench top for 24 hours before final drying at 110° C. to arrive at the xerogel. 
     X-Ray Diffraction of Composite Material 
     Samples for X-Ray diffraction (XRD) were prepared by drop wise addition of the PPPS or PEDOPPS V 2 O 5  sol-gel composites to glass slides. The deposit areas were on the order of 3 cm 2 . All samples were dried on the bench top for 8 hours prior to drying under vacuum at 110° C. for 24 hours. XRD data was gathered on a Scintag X-2000 powder diffractometer at a rate of 2° Θ/min. between 2 and 70 2Θ with Cu Kα radiation. The results are depicted in  FIGS. 11 and 12 . 
     Trace  36  in  FIG. 11  shows the XRD data for V 2 O 5 . Traces  38 ,  40  and  42  show the corresponding XRD data of V 2 O 5 /PPPS composites with varying amounts of PPPS. The d-spacings for layer to layer distances in V 2 O 5  xerogels can be a function of the water content of the material. The range is reported to be from 13 to 8.5 Å for water contents from 3 to 0.8 molecules of water for each V 2 O 5  unit. Trace  36  in  FIG. 11  for an unmodified V 2 O 5  sample shows a reflection in the 001 plane at 6.8° 2Θ corresponding to a layer spacing of 13 Å. Traces  40  and  42  can be for PPPS modified samples and all show a 001 reflection 6.2° 2Θ corresponding to a layer spacing of 14.3 Å. The wider layer separation can be due to inclusion of PPPS chains between the vanadium layers. The trend with increasing PPPS concentration is a broadening of the 001 peak characteristic of a decrease in domain size. This trend indicates, that as the polymer is added to the system, the short range order of the xerogel matrix decreases, forcing the V 2 O 5  bi-layer ribbons to adopt a more amorphous morphology. 
     Trace  44  in  FIG. 12  at approximately 8° 2Θ shows a reflection in the 001 plane and corresponds to a layer spacing of 11.5 Å. Traces  46  and  48  in  FIG. 12  show a growth of a peak at 2.5 2Θ corresponding to a layer spacing of 35 Å with increasing concentration of PEDOPPS. 
     Electron Diffraction of Composite Material 
     In addition to the structural information obtained by the XRD experiments, electron diffraction was used to further clarify the molecular level changes brought on by polymer inclusion in the V 2 O 5  matrix. Samples were prepared by dipping gold coated transmission electron microscopy grids into V 2 O 5  and 300 ppm V 2 O 5 /PPPS hydrogels. The coated grids were dried on the bench top for 24 hours before additional drying at 10° C. under vacuum. One of two V 2 O 5 /PPPS coated grids was used as the working electrode in a typical 3 electrode cell and underwent a two electron reduction simulating discharge. 
       FIGS. 13   a - 13   c  show the electron diffraction patterns for V 2 O 5  and the 300 ppm V 2 O 5 /PPPS composite in the oxidized and reduced states. The parent material ( FIG. 13   a ) shows well defined spots that are characteristic of a crystalline material. Indexing of this diffraction pattern agrees well with values known in the art.  FIG. 13   b  shows the diffraction pattern for V 2 O 5  composite including 300 ppm PPPS. The diffraction pattern is less defined and is characteristic of a material that has a very small crystallite size. Indexing of this pattern shows that the atomic arrangements have not been altered. There has been a reduction in the domain size. 
       FIG. 13   c  is the diffraction pattern of a V 2 O 5  composite including 300 ppm PPPS after a two electron reduction. Several of the rings present in the prepared material ( FIG. 13   b ) are absent in  FIG. 13   c  suggesting that lithium intercalation causes a random rearrangement of the structure. The rings that do remain match indexing associated with both the parent and PPPS modified samples. These data suggest there are measurable changes occurring in the structure of V 2 O 5  both with polymer inclusion and lithium intercalation. 
     The electrochemical enhancement of V 2 O 5  due to PPPS inclusion can be because the polymer chains form a template that controls and directs the growth of V 2 O 5 . The templating can occur in the vicinity of the highly dispersed polymer chains and the pattern (or lack thereof) is then repeated through the growing V 2 O 5  matrix. In effect, the polymer is directing the disorder in structure of the V 2 O 5  on the bi-layer molecular level as is indicated by the electron diffraction results. 
     V 2 O 5 /Conducting Polymer Composite Micron Particulate Formation 
     V 2 O 5 /PPPS composite was milled to reduce particle size.  FIG. 14  shows the particle size distribution for milled composite cathode material. d 10 =0.47 μm, d 50 =1.6 μm, d 90 =8 μm. Trace  50  in  FIG. 14  corresponds to the “probability density function” and trace  52  corresponds to the “cumulative distribution function.” The particle size analysis shown in  FIG. 14  indicates a bimodal distribution with 90% of the particles under 8 μm. 
     Test Results 
     The cathode formulation was paired with both lithium metal and graphite anodes in several different cell configurations to ascertain the performance characteristics. In all cases the electrolyte used was 1.0 M LiPF 6  in a 1:1 mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC). The separator material used was Celgard 2800, a 21 μm thick polyethylene membrane with 43% porosity that is typically used in lithium-ion battery applications. Charge/discharge conditions were controlled with Maccor battery testers. 
     V 2 O 2  Composite Cathode Vs. Lithium Anode 
     Initial testing on the cathode was performed using a lithium metal anode to eliminate complications to the electrochemistry brought on by contributions from a graphite intercalation anode. The lithium used was 99.99% pure foil that was roll milled to a thickness of ˜100 μm prior to cleaning in an inert atmosphere with hexanes and acetone. Appropriate sizes based on the test vehicle being used were cut from the foil stock with punches. 
     Discharge curves at the third cycle for three puck cells including V 2 O 5  composite cathode and lithium metal anode at three discharge rates appear in  FIG. 15 . The capacity is reported as a function of the mass of the V 2 O 5  active material. The samples show a rate dependant capacity response. Over the discharge rate range of C/20 to C/5 the measured capacity decreases from 275 mAh/g to 210 mAh/g. These data clearly indicate that, at moderate rates, the V 2 O 5  composite shows very attractive capacity. 
       FIG. 16  shows the discharge capacities for two 2016 coin cells including V 2 O 5  composite cathode and lithium metal anode. The data points of trace  54  show fluctuations in capacity over 13 cycles with eventual deterioration due to lithium dendrite formation. On the other hand, the data points of trace  54  show excellent capacity, greater than 300 mAh/g, for the first eleven cycles. This suggests that the composite V 2 O 5  cathode material, when formulated and deposited as a typical industrially acceptable material, has the potential to drastically improve rechargeable lithium ion battery performance. 
       FIG. 17  compares the polarization of a typical LiCoO 2  based 18650 cell with one of the large format V 2 O 5 /PPPS cells. In this experiment a similar discharge current was applied to both of the cells and was then interrupted. The measured change in voltage upon switching from the load to no-load condition is a combination of the electrical and chemical polarization of the particular system and can be referred to as the recovery voltage. Examination of the plot shows that the polarization for the V 2 O 5 /PPPS cell is ˜0.4 volts while the same for the 18650 cell is approximately 0.10 V. This suggests that the V 2 O 5 /PPPS material is inherently more resistive than LiCoO 2 . 
     Variations, modifications, and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention. Accordingly, the invention is not to be limited only to the preceding illustrative descriptions.