Electrode slurry composition for lithium ion electrical storage devices
The present invention provides a slurry composition comprising (a) a binder comprising a polymer comprising a fluoropolymer dispersed in a liquid medium; and (b) at least one conductive carbon material having a BET surface area of greater than 100 m 2 /g. Also provided are electrodes and electrical storage devices.
1. A slurry composition comprising:
(a) a binder comprising a polymer comprising a fluoropolymer dispersed in an organic medium comprising a primary solvent and a co-solvent; and
(b) at least one conductive carbon material having a BET surface area of greater than 100 m 2 /g,
wherein the organic medium is substantially free of water.
2. The slurry composition of claim 1 , wherein the conductive carbon material has a BET surface area of 100.1 m 2 /g to 1,000 m 2 /g.
3. The slurry composition of claim 1 , wherein the conductive carbon material has a BET surface area of 200 m 2 /g.
4. The slurry composition of claim 1 , further comprising an electrochemically active material.
5. The slurry composition of claim 4 , wherein
(a) the binder is present in amounts of 2 to 20 percent by weight;
(b) the conductive carbon material is present in amounts of 2 to 20 percent by weight; and
(c) the electrochemically active material is present in amounts of 45 to 96 percent by weight; the percentages by weight being based on total solids weight.
6. The slurry composition of claim 4 , wherein the electrochemically active material comprises a material capable of incorporating lithium comprising LiCoO 2 , LiNiO 2 , LiFePO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAl)O 2 , carbon-coated LiFePO 4 , or a combination thereof.
7. The slurry composition of claim 4 , wherein the electrochemically active material comprises a material capable of lithium conversion comprising sulfur, LiO 2 , FeF 2 , FeF 3 , Si, aluminum, tin, SnCo, Fe 3 O 4 , or combinations thereof.
8. The slurry composition of claim 4 , wherein the electrochemically active material comprises graphite, silicon compounds, tin, tin compounds, sulfur, sulfur compounds, or a combination thereof.
9. The slurry composition of claim 1 , wherein the fluoropolymer comprises a polyvinylidene fluoride polymer.
10. The slurry composition of claim 1 , further comprising a dispersant comprising an addition polymer.
11. The slurry composition of claim 10 , wherein the addition polymer comprises a (meth)acrylic polymer comprising constitutional units comprising a residue of methyl methacrylate and constitutional units comprising a residue of ethylenically unsaturated monomer comprising a heterocyclic group.
12. The slurry composition of claim 10 , wherein the composition further comprises a cross-linker.
13. The slurry composition of claim 1 , wherein the organic medium has an evaporation rate less than 10 g/min m 2 , at the dissolution temperature of the fluoropolymer dispersed in the organic medium.
14. The slurry composition of claim 1 , wherein the primary solvent comprises butyl pyrrolidone, a trialkylphosphate, 3-methoxy-N,N-dimethylpropanamide, 1,2,3-triacetoxypropane, or a combination thereof, and the co-solvent comprises ethyl acetoacetate, gamma-butyrolactone, and/or glycol ethers.
15. The slurry composition of claim 1 , wherein the primary solvent comprises triethyl phosphate and the co-solvent comprises ethyl acetoacetate.
16. The slurry composition of claim 1 , further comprising an adhesion promoter.
17. An electrode comprising:
(a) an electrical current collector; and
(b) a film formed on the electrical current collector, wherein the film is deposited from the slurry composition of claim 4 .
18. The electrode of claim 17 , wherein the film is cross-linked.
19. An electrical storage device comprising:
(a) the electrode of claim 18 ;
(b) a counter electrode; and
(c) an electrolyte.
20. The electrical storage device of claim 19 , wherein the electrical storage device comprises a cell, a battery pack, a secondary battery, a capacitor, or a supercapacitor.