Electrode binder slurry composition for lithium ion electrical storage devices
The present invention provides a slurry composition comprising (a) an electrochemically active material and/or an electrically conductive agent; and (b) a binder comprising (i) a polymer comprising a fluoropolymer dispersed in a liquid medium; and (ii) a polymer comprising an addition polymer comprising constitutional units comprising the residue of a heterocyclic group-containing ethylenically unsaturated monomer. The present invention also provides electrodes and electrical storage devices.
1. A binder composition for use in an electrode slurry composition, wherein the binder composition comprises:
(i) a polymer comprising a fluoropolymer dispersed in an organic medium comprising at least 90% by weight of an organic solvent, based on the total weight of the organic medium; and
(ii) a dispersant comprising an addition polymer comprising constitutional units comprising the residue of a heterocyclic group-containing ethylenically unsaturated monomer comprising vinyl pyrrolidone.
2. The binder composition of claim 1 , wherein the addition polymer further comprises constitutional units comprising the residue of methyl (meth)acrylate.
3. The binder composition of claim 2 , wherein the addition polymer comprises constitutional units comprising 1% to 99% by weight of the residue of vinyl pyrrolidone and 1% to 99% by weight of the residue of methyl (meth)acrylate, the % by weight based on the total weight of the addition polymer.
4. The binder composition of claim 1 , wherein the binder composition further comprises a second addition polymer comprising the residue of a heterocyclic group-containing ethylenically unsaturated monomer comprising an epoxy functional ethylenically unsaturated monomer.
5. The binder composition of claim 1 , wherein the binder composition further comprises a second addition polymer comprising the residue of a heterocyclic group-containing ethylenically unsaturated monomer comprising an epoxy functional ethylenically unsaturated monomer and a compound having a functional group reactive with the epoxy functional group is grafted onto the second addition polymer by reaction with the epoxy functional group.
6. The binder composition of claim 1 , wherein the liquid medium comprises an organic medium having an evaporation rate of less than 10 g/min m 2 , at the dissolution temperature of the fluoropolymer dispersed in the organic medium.
7. The binder composition of claim 1 , wherein the organic medium has an evaporation rate greater than 80 g/min m 2 , at 180° C.
8. The binder composition of claim 1 , wherein the organic medium comprises butyl pyrrolidone, trialkylphosphate, 1,2,3-triacetoxypropane, 3-methoxy-N,N-dimethylpropanamide, ethyl acetoacetate, gamma-butyrolactone, propylene glycol methyl ether, or combinations thereof.
9. The binder composition of claim 1 , wherein the organic medium comprises a primary solvent comprising trialkylphosphate and a co-solvent.
10. The binder composition of claim 1 , wherein the organic medium comprises a primary solvent comprising triethyl phosphate and a co-solvent comprising ethyl acetoacetate.
11. The binder composition of claim 1 , further comprising a third addition polymer, wherein the third addition polymer is free of heterocyclic groups.
12. The binder composition of claim 1 , wherein the composition is substantially free of isophorone.
13. The binder composition of claim 1 , wherein the composition is substantially free of N-methyl-2-pyrrolidone.
14. A slurry composition comprising:
(a) an electrochemically active material and/or an electrically conductive agent; and
(b) the binder composition of claim 1 .
15. The slurry composition of claim 14 , wherein the electrically conductive agent is present and comprises graphite, acetylene black, furnace black, graphene, carbon nanotubes, or combinations thereof.
16. The slurry composition of claim 14 , wherein the electrically conductive agent is present and comprises carbon nanotubes.
17. The slurry composition of claim 14 , wherein the electrically conductive agent is present and comprises conductive carbon material having a surface area of 100 m 2 /g to 1,000 m 2 /g.
18. A slurry composition comprising:
(a) carbon nanotubes; and
(b) the binder composition of claim 1 .
19. 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 14 .
20. An electrical storage device comprising:
(a) the electrode of claim 19 ;
(b) a counter electrode; and
(c) an electrolyte.