Binder compositions for batteries

Abstract

Provided are battery binder compositions. In embodiments, a battery binder composition comprises cellulose in the form of nanocellulose or microcellulose, the cellulose comprising electrode binding groups and solvent dispersing groups; and a non-aqueous solvent system. Battery electrodes and batteries comprising the battery binder compositions are also provided.

Description

BINDER COMPOSITIONS FOR BATTERIESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. provisional patent application number 63 / 627,256 that was filed January 31, 2024, the entire contents of which are incorporated herein by reference.REFERENCE TO GOVERNMENT RIGHTS

[0002] This invention was made with government support under 2037026 awarded by the National Science Foundation. The government has certain rights in the invention.BACKGROUND

[0003] Binders are used in batteries in order to bind active materials and conductors onto current collectors. Choices of binders for the cathodes of lithium-ion batteries (LIBs) are limited, which generally make use of poly vinylidene difluoride (PVDF) and a strong solvent such as N-methyl-2-pyrroridone (NMP). Some aqueous binder compositions have been developed as an alternative to PVDF / NMP.SUMMARY

[0004] Provided are battery binder compositions. Battery electrodes and batteries comprising the battery binder compositions are also provided.

[0005] In embodiments, a battery binder composition comprises cellulose in the form of nanocellulose or microcellulose, the cellulose comprising electrode binding groups and solvent dispersing groups; and a non-aqueous solvent system.

[0006] Other principal features and advantages of the disclosure will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Illustrative embodiments of the disclosure will hereafter be described with reference to the accompanying drawings.

[0008] FIG. 1 shows the cyclic performance of a LiNi0.83Mn0.1Co0.07O2 (Ni83) cathode using a C6CNC in DMSO binder composition. The results show that the charge / discharge curves for Cell 1 and Cell 2 substantially overlap.

[0009] FIG. 2 shows the cyclic performance of a LiFePO4 cathode using a C6CNC in DMSO binder composition. The results show that the charge / discharge curves for Cell 1 and Cell 2 substantially overlap. In addition, the Coulombic efficiency curves for Cell 1 and Cell 2 also substantially overlap.

[0010] FIG. 3 shows the cyclic performance of Ni83 cathodes using a C2CNC in DMSO binder composition and C4CNC in DMSO binder composition. Also shown are Ni83 cathodes using a comparative PVDF in NMP binder composition and a comparative CNCA in water binder composition. The curve for Cell 2, C2CNC is substantially underneath the curve for Cell 2, C4CNC.

[0011] FIG. 4A shows the cyclic performance of aNMC811 cathode using a C4CNC in DMSO binder composition. Also shown are NMC811 cathodes using a comparative PVDF in NMP binder composition and a comparative CNCA in water binder composition. The curves for PVDF and C4CNC are substantially overlapping. FIG. 4B shows images of the electrodes after 100 cycles. Images ofNMC811 electrode sheets coated using C4CNC / DMSO binder composition and comparative PVDF / NMP and CNCA / water binder compositions, respectively, were also obtained (not shown).

[0012] FIG. 5 A shows the charge / discharge curves of aNMC811 (using a C4CNC in DMSO binder composition)||graphite full cell. FIG. 5B shows the cyclic performance for the cell. The charge / discharge curves substantially overlap.

[0013] FIG. 6 shows the cyclic performance of aNMC811 cathode using a C4CNC in Cyrene binder composition. The charge / discharge curves substantially overlap.

[0014] FIG. 7 shows the cyclic performance of aNMC811 cathode using a C4CNC in hexanol binder. The charge / discharge curves substantially overlap.DETAILED DESCRIPTION

[0015] Provided are battery binder compositions based on cellulose. Battery electrodes and batteries comprising the battery binder compositions are also provided.

[0016] The present battery binder compositions comprise (or consist of) cellulose and a non-aqueous solvent system. The cellulose is in the form of bundles of individual cellulose molecules. The cellulose bundles may be characterized by their dimensions (including length, diameter, and aspect ratio), crystallinity, source from which the cellulose bundles are extracted, as well as processing technique used to extract the cellulose bundles, none of which are particularly limited. Thus, the term “cellulose” encompasses various types of cellulose in the form of bundles, including microcellulose, nanocellulose, cellulose nanocrystals (CNCs), cellulose nanofibers, and cellulose microfibrils. A single type of cellulose may be used (e.g., only CNCs), or multiple, different types of cellulose may be used. Using CNCs as an example, depending upon the natural source of the cellulose and the extraction technique, the crystallinity index of the CNCs can range from 70% to 95%, the width can range from 5 nm to 30 nm, the length can range from hundreds of nanometers to a few micrometers, and the aspect ratio can range from 10-100. These characteristics distinguish CNCs from other types of cellulose.

[0017] The cellulose of the present battery binder compositions is functionalized to include both electrode binding groups and solvent dispersing groups, both of which are covalently bound to individual cellulose molecules from which the cellulose bundles are composed. An electrode binding group refers to a chemical group capable of facilitating adhesion between materials of a battery electrode (e.g., the functionalized cellulose, electrode active material, conductive agent, current collector). This may occur due to the electrode binding group being capable of covalent and / or non-covalent (e.g., ionic, hydrogen bonds, hydrophobic, van der Waals) associations with one or more of the materials from which a battery electrode is composed. The electrode binding group may be a group capable of binding (covalently and / or non-covalently) to a metal. The metal may refer to a neutral atom or to an ion thereof. The metal may be a metal of the electrode active material. Thus, the particular metal depends upon the electrode active material, which is further described below. However, illustrative metals include alkali metals (e.g., Li, etc.) and transition metals (e.g., Co, Ni, Mn, Al, Fe, etc.). Electrode binding groups capable of binding to metals include hydroxy ( — OH), carbonyl ( — C(O) — ), carboxyl ( — C(O)OH), and ether ( — O — ). The “ — ” represents a covalent bond, at least one of which in the electrode binding group is a covalent linkage to the cellulose of the battery binder composition. This covalent linkage may be direct or indirect, i.e., via a linking group. Other illustrative electrode binding groups capable of binding to metals include nitrogen-containing groups, sulfate half ester groups ( —0S(0)20H), and phosphate groups ( — 0P(0)(0H)2). Illustrative nitrogen-containing groups include amidine, amines, urethanes, pyridine, pyrrole, imides, and urea. A single type (same chemical formula) of electrode binding group (e.g., only hydroxy groups) or multiple, different types (different chemical formulas) of electrode binding groups may be used.

[0018] A solvent dispersing group refers to a chemical group capable of facilitating dispersion of the cellulose into the non-aqueous solvent system. This may occur due to the solvent dispersing group being at least partially miscible (including fully miscible) with the non-aqueous solvent system. Thus, the particular solvent dispersing group depends upon the non-aqueous solvent system, which is further described below. However, illustrative groups include alkyl, aryl, carbonyl, and ether. The alkyl group may be a linear, branched, or cyclic alkyl group. A linear alkyl group may be represented by — CnH2n+i. The “ — ” represents a covalent bond, at least one of which in the solvent dispersing group is a covalent linkage to the cellulose of the battery binder composition. This covalent linkage may be direct or indirect, i.e., via a linking group. The number of carbons (n) may be, e.g., in a range from 1 to 20. This includes from 2 to 18, from 4 to 16, and from 6 to 14. An aryl group refers to a monocyclic aryl group having one aromatic ring (e.g., phenyl) or a polycyclic group having more than one aromatic ring (e.g., naphthalene, pyrene). Carbonyl and ether groups have been defined above. The solvent dispersing group may be a polymeric group, e.g., polyethylene glycol (PEG). The polymeric group may have a molecular weight of at least 500 g / mol. As with the electrode binding group, there is at least one covalent linkage (direct or indirect) of the solvent dispersing group to the cellulose of the battery binder composition. In embodiments, this covalent linkage is indirect involving an amide bond as a linking group between the cellulose and the solvent dispersing group. A single type (same chemical formula) of solvent dispersing group (e.g., only alkyl groups) or multiple, different types (different chemical formulas) of solvent dispersing groups may be used. Although there is some overlap between the types of chemical groups provided above for electrode binding groups and solvent dispersing groups, the selected solvent dispersing group(s) and the selected electrode binding group(s) being used to functionalize the cellulose of the battery binding composition are different chemical species from one another.

[0019] The type of electrode binding group, the type of solvent dispersing group, and the relative amount of these groups on the cellulose of the battery binding composition may be adjusted based on desired battery properties, e.g., maximum capacity retention.

[0020] The cellulose of the present battery binding compositions may be functionalized using known chemical synthetic techniques. The Example below describes an illustrative technique for functionalizing cellulose with carboxyl groups (via TEMPO oxidation) and alkyl groups (by reacting some of the carboxyl groups with primary alkylamines via carbodiimide crosslinking to form amide bond linking groups).

[0021] In addition to the functionalized cellulose, the present battery binder compositions comprise the non-aqueous solvent system. “Non-aqueous” refers to the use of solvents other than water. In embodiments, the non-solvent system and the battery binder composition may be characterized as being free of water. However, due to the inherent nature of chemical synthesis, “free” does not require a perfect absence of water in the solvent or the battery binder composition. One or more solvents may be used to form the non-aqueous solvent system, including dimethyl sulfoxide, Cyrene (dihydrolevoglucosenone), an alcohol (e.g., butanol, pentanol, hexanol), a ketone (e.g., cyclopentanone), or an ester (e.g., ethyl acetoacetate). In addition to being free of water, the solvent system and the battery binder composition may be free of certain solvents, e.g., N-methyl-2-pyrrolidone (NMP). This does not preclude the presence of a small amount of NMP in the solvent system and the battery binder composition, e.g., no more than 5%, no more than 4%, no more than 3%, no more than 2%, or no more than 1%. The particular selection of solvents for the non-aqueous solvent system may depend upon the selected electrode binding groups as well as the desired battery in which the battery binding composition is to be used. The relative amount of the functionalized cellulose and the non-aqueous solvent system (as well as the relative amount of solvents therein) may be selected based on desired battery properties, e.g., maximum capacity retention.

[0022] The present battery binder compositions may further include other components, such as those generally used to form battery electrodes, e.g., an electrode active material and a conductive agent. In embodiments, the battery binder composition comprises (or consists of) the functionalized cellulose, the non-aqueous solvent system, the electrode active material, and optionally, the conductive agent. The electrode active material may be a cathode electrode material or an anode electrode material. Otherwise, the composition of the electrode active material depends upon the type of battery. The battery may be a metal (or a metal -ion) battery, e.g., a lithium metal battery or a lithium-ion battery'. Illustrative cathode electrode materials suitable for lithium metal (or lithium-ion) batteries and thus, which may be included in any of the disclosed battery binder compositions, include LiCoO2 (LCO),LiNii-x-yMnxCoyCh (NMC), LiNii-x-yCoxAlyCh (NCA), and LiFePCk Various values of x and y may be used, including the illustrative compositions provided in the Example, below. The battery electrode active materials may be modified (e.g., doped or coated) to enhance the battery performance. A variety of conductive agents may be used, e.g., carbon black. The relative amounts of the “binding” component of the battery binder composition (i.e., the functionalized cellulose dispersed in its non-aqueous solvent system), the electrode active material, and if present, the conductive agent, may be selected based on desired battery properties, e.g., maximum capacity retention.

[0023] To form the battery electrode (which may be an anode or a cathode), the battery binder composition comprising (or consisting of) the functionalized cellulose, the nonaqueous solvent system, the electrode active material, and if present, the conductive agent, is placed in contact with (e.g., by coating) a current collector (e.g., a conductive metal). The battery is formed by further including a counter electrode (the other of the anode or the cathode) in electrical communication with the battery electrode, and an electrolyte composition therebetween. Any suitable counter electrode and electrolyte composition may be used, depending upon the desired battery. Other components generally used in the battery may be used, e.g., a separator.

[0024] Illustrative battery binding compositions, battery cathodes, and lithium-ion batteries are described in the Example below. The excellent adhesion exhibited by battery cathodes incorporating the present battery binding compositions is illustrated in FIG. 4B. Similarly, the excellent cyclic performance of the battery' cathodes and lithium-ion batteries incorporating the battery cathodes is illustrated in FIGS. 1, 2, 3, 4A, 5A-5B, 6, and 7.EXAMPLE

[0025] This Example describes the synthesis of functionalized cellulose nanocrystals and binder compositions made therefrom. Fabrication and testing of electrodes and batteries formed using the binder compositions are also described.

[0026] Preparation of CNC-COOH: Cellulose nanocrystals (CNC) were isolated from Miscanthus x. Giganteus (MxG) stalks by NaOH washing, NaCICh bleaching, and HC1 hydrolysis, and then further oxidized by 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) oxidation to obtain carboxylic acid functionalized cellulose nanocrystals (CNC-COOH). (See Cudjoe, Elvis, et al. Carbohydrate polymers 155 (2017): 230-241.)

[0027] Synthesis of CNC-COOH-Ethyl (C2CNC) and CNC-COOH-Butyl (C4CNC):Preparation followed the protocol described in Zhang, Yefei, et al., Macromolecules 50.16 (2017): 6032-6042, except that Dimethylformamide (DMF) was not used. CNC-COOH (100 mg) was dispersed in 18 mL DI water via probe sonication, and then 2 mL of phosphate buffered saline (PBS) IX was added to the CNC dispersion. 0.20 g (1.04 mmol) of (1-ethyl- 3-(-3-dimethylaminopropyl) carbodiimide) EDC and 0.12 g (1.04 mmol) ofN- Hydroxysuccinimide (NHS) were added, then pH was adjusted to 4.0, and the reaction was stirred for 30 min. Next, a certain amount of ethylamine (Et-NH2) or butylamine (BU-NH2) (e.g., 3.6 mg (0.08 mmol) of Et-NH2 or 0.5 mL (370 mg) of BU-NH2) was added, pH was adjusted to 9.0, and the reaction was stirred at room temperature overnight. The reaction mixture was then centrifuged to yield C2CNC (or C4CNC) as a white precipitate. The product was then dispersed in deionized (DI) water and dialyzed against DI water for 3 days, and finally lyophilized to yield C2CNC (or C4CNC).

[0028] Synthesis of CNC-COOH-Hexyl (C6CNC) and CNC-COOH-Octyl (C8CNC): Preparation followed the protocol described above for C2CNC and C4CNC. CNC-COOH (100 mg) was dispersed in 18 mL DI water via probe sonication, 2 mL of PBS IX was then added to the CNC dispersion, and pH of the suspension was adjusted to 4.0. 20 mL of methanol was slowly added on top of the CNC solution, and the solution was shaken gently overnight. 0.20 g (1.04 mmol) of EDC and 0.12 g (1.04 mmol) of NHS were added, and the reaction was stirred for 30 min. Then a certain amount of hexylamine (Hex-NTH) or octylamine (Oct-NH2) (e.g., 0.26 g (2.0 mmol) of Oct-NTL) was added, pH was adjusted to 9.0, and the reaction was stirred at room temperature overnight. The reaction mixture was then centrifuged to yield C6CNC (or C8CNC) as a white precipitate. The product was then dispersed in DI water and dialyzed against DI water for 3 days, and finally lyophilized to yield C6CNC (or C8CNC).

[0029] Preparation of Electrodes and Coin Cells. The charge / discharge performance was characterized by using 2032-type coin cells that were assembled in an argon-filled glove box, with oxygen and moisture content below 1 ppm. Electrodes were prepared by mixing certain cathode materials as the active material (see below); the functionalized CNCs prepared above (i.e., either C2CNC, C4CNC, C6CNC, or C8CNC) in a selected solvent (DMSO, Cyrene, or hexanol) as the binder composition; and carbon black as the conductive agent with a weight ratio of 93:2:5 to form a slurry. The resulting slurries were coated onto an Al foil (18-pm in thickness) current collector using the doctor blade method. After drying andpressing, the Al foil was cut into disks (10 mm in diameter) with typical electrode material loadings of ca. 8 mg cm'2. A graphite anode was used as the anode for the full cells; the capacity ratio of anode to cathode (N / P ratio) was approximately 1.2. I M LiPFr, dissolved in ethylene carbonate / ethyl methyl carbonate (40:60, v / v) with additives of fluoroethylene carbonate (5 wt. %) and vinylene carbonate (2 wt. %) employed as an electrolyte.

[0030] Results

[0031] C6CNC inDMSO

[0032] C6CNC was dispersed in dimethyl sulfoxide (DMSO) to form a binder composition for a LiNi0.83Mn0.1Co007O2 (Ni83) cathode. The capacity of the Ni83 cathode at 24 mA / g was approximately 196 mAh / g, and the reversible capacity at 120 mA / g was approximately 179 mAh / g. The capacity retention was 92.5%, 85.4%, and 67.2% after 100, 200, and 500 cycles, respectively (FIG. 1). When the C6CNC in DMSO binder composition was used for a LiFePO4 (LFP) cathode, the initial capacity at 17 mA / g (C / 10) was 150.2 mAh / g with an initial Coulombic efficiency of 94.5%. The reversible capacity of the LFP electrode at 85 mA / g (C / 2) was approximately 146 mAh / g which only reduced to 143 mAh / g after 500 cycles, corresponding to a capacity retention of 98% (FIG. 2).

[0033] C2CNC and C4CNC in DMSO

[0034] Both C2CNC and C4CNC were dispersed in DMSO to form a binder composition for Ni83 cathodes. Polyvinylidene difluoride in N-methyl-2-pyrroridone (PVDF in NMP) and CNC-COOH in water (aqueous CNCA) were used as two separate comparative binder compositions. As shown in FIG. 3, the capacities of the Ni83 cathodes at 24 mA / g (0.1C) were approximately 195 mAh / g for all the binder compositions. At 240 mA / g (1C), the reversible capacity for comparative Ni83 with aqueous CNCA was 168 mAh / g and the capacity retention was 48% after 500 cycles. In contrast, the Ni83 cathodes with either C2CNC or C4CNC in DMSO showed a reversible capacity of 171 ± 2 mAh / g at 240 mA / g and the capacity retention was 72% after 500 cycles. At 240 mA / g, the reversible capacity for comparative Ni83 with PVDF in NMP was 166 mAh / g which reduced to 108 mAh / g for cell 1, corresponding to 65% of capacity retention after 500 cycles. Note that cell 2 for comparative Ni83 with PVDF in NMP exhibited fast capacity decay after around 400 cycles, possibly due to decay from the Li electrode.

[0035] C4CNC inDMSO

[0036] C4CNC dispersed in DMSO was used as the binder composition for a LiNio.8Mno.1Coo.1O2 (NMC811) cathode. Aqueous CNCA and PVDF in NMP were used as separate comparative binder compositions. As shown in FIG. 4A, the capacities of the NMC811 cathode at 20 mA / g (C / 10) were approximately 189 mAh / g for all the binder compositions. The NMC811 with either C4CNC in DMSO or comparative PVDF in NMP showed very similar cyclic performance, both exhibiting a reversible capacity of approximately 168 mAh / g, reducing to 156 mAh / g after 100 cycles. In contrast, the NMC811 with comparative aqueous CNCA exhibited a reversible capacity of 162 mAh / g which reduced to 144 mAh / g after 100 cycles.

[0037] After 100 cycles, the com cells with comparative aqueous CNCA and with C4CNC in DMSO were dissembled. As shown in FIG. 4B, while the cathode with C4CNC in DMSO remained intact, some of the electrode material detached from the substrates. In addition, other images were obtained (not shown) for the electrodes coated with the three binder compositions: PVDF in NMP, C4CNC in DMSO, and aqueous CNCA (FIG 4E), indicating that the cathodes with PVDF in NMP and C4CNC in DMSO were uniformly coated, while the cathode with aqueous CNCA was not uniform.

[0038] The NMC811 with C4CNC in DMSO was assembled with a graphite anode to form a NMC811||graphite full cell, which delivered 189.6 mAh / g at 20 mA / g (C / 10) and a reversible capacity of approximately 165 mAh / g (FIG. 5 A). After 1,000 cycles, the capacity remained at 131.9 mAh / g, corresponding to a capacity retention of 79.9% (FIG. 5B).

[0039] C4CNC in Cyrene

[0040] C4CNC was dispersed in Cyrene to form a binder composition for a NMC811 cathode. As shown FIG. 6, the capacity of NMC811 with C4CNC in Cyrene at 20 mA / g (C / 10) was approximately 187 mAh / g. At 200 mAh / g (1C), the capacity was 163 mAh / g which reduced to 128 mAh / g after 400 cycles.

[0041] C4CNC in hexanol

[0042] C4CNC was dispersed in hexanol to form a binder composition for a NMC811 cathode. As shown in FIG. 7, the NMC811 cathode delivered an initial capacity of 189.5 mAh / g at 20 mA / g with an initial Coulombic efficiency of 88%. The reversible capacity at 200 mA / g was approximately 170 mAh / g and the capacity retention was 86% after 100 cycles.

[0043] The word "illustrative" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, "a" or "an" means "one or more.”

[0044] The foregoing description of illustrative embodiments of the disclosure has been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosure. The embodiments were chosen and described in order to explain the principles of the disclosure and as practical applications of the disclosure to enable one skilled in the art to utilize the disclosure in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the claims appended hereto and their equivalents.

[0045] If not already included, all numeric values of parameters in the present disclosure are proceeded by the term “about” which means approximately. This encompasses those variations inherent to the measurement of the relevant parameter as understood by those of ordinary skill in the art. This also encompasses the exact value of the disclosed numeric value and values that round to the disclosed numeric value. Terms such as “comprising” and the like may be replaced with terms such as “consisting” and the like.

Claims

WHAT IS CLAIMED IS:

1. A battery binder composition, the composition comprising cellulose in the form of nanocellulose or microcellulose, the cellulose comprising electrode binding groups and solvent dispersing groups; and a non-aqueous solvent system.

2. The battery binder composition of claim 1, wherein the cellulose is in the form of cellulose nanocrystals, cellulose nanofibers, cellulose microfibrils, or combinations thereof.

3. The battery binder composition of claim 1, wherein the electrode binding groups are capable of binding to a metal.

4. The battery binder composition of claim 1, wherein the electrode binding groups are selected from hydroxyl groups, ether groups, carbonyl groups, carboxyl groups, nitrogencontaining groups, sulfate half ester groups, phosphate groups, and combinations thereof.

5. The battery binder composition of claim 1, wherein the solvent dispersing groups is selected from alkyl groups, aryl groups, carbonyl groups, ether groups, and combinations thereof.

6. The battery binder composition of claim 1, wherein the electrode binding groups comprise hydroxyl groups and carboxyl groups and the solvent dispersing groups comprise alkyl groups.

7. The battery binder composition of claim 6, wherein the alkyl groups are selected from ethyl, butyl, hexyl, octyl, and combinations thereof.

8. The battery binder composition of claim 6, wherein the alkyl groups are covalently bound to the cellulose via amide bonds.

9. The battery binder composition of claim 1, wherein the non-aqueous solvent system comprises a solvent selected from dimethyl sulfoxide, Cyrene, an alcohol, a ketone, an ester, and a combination thereof.

10. The battery binder composition of claim 1, wherein the non-aqueous solvent system and the battery binder composition is free of N-methyl-2-pyrrolidone.

11. The batery binder composition of claim 1, further comprising an electrode active material, and optionally, a conductive agent.

12. The batery binder composition of claim 11, wherein the electrode active material is a cathode active material for a metal or a metal-ion batery.

13. The batery binder composition of claim 12, wherein the cathode active material is selected from LiCoCh (LCO), LiNii-x-yMmCoyCh (NMC), LiNii-x-yCoxAlyCh (NCA), LiFePCh. and combinations thereof.

14. The batery binder composition of claim 1, wherein the cellulose is in the form of cellulose nanocrystals; the electrode binding groups comprise hydroxyl groups and carboxyl groups and the solvent dispersing groups comprise alkyl groups covalently bound to the cellulose via amide bonds; and the battery binder composition is free of N-methyl-2- pyrrolidone.

15. The batery binder composition of claim 14, wherein the alky l groups are selected from ethyl, butyl, hexyl, octyl, and combinations thereof.

16. The batery binder composition of claim 15, wherein the non-aqueous solvent system comprises a solvent selected from dimethyl sulfoxide, Cyrene, hexanol, and combinations thereof.

17. The batery binder composition of claim 16, consisting of the cellulose, the nonaqueous solvent system, and optionally, one or more of a cathode active material and a conductive agent.

18. A batery comprising the batery binder composition of claim 1, an anode, a cathode, and an electrolyte composition.

19. The batery of claim 18, wherein the batery' binder composition is in contact with the cathode.

20. The batery of claim 19, wherein the cathode comprises a current collector and a cathode active material selected from LiCoCh (LCO), LiNii-x-yMnxCoyO2 (NMC), LiNii-x-yCoxAlyO2 (NCA), LiFePOr. and combinations thereof.

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