Electrode binder slurry composition for lithium ion electrical storage devices
The present invention provides a slurry composition comprising a binder comprising a polymer comprising a fluoropolymer dispersed in a liquid medium; an adhesion promoter; and at least one of an electrochemically active material or an electrically conductive agent. The present invention also provides electrodes and electrical storage devices.
1 . A slurry composition comprising:
(a) an electrochemically active material;
(b) a binder comprising a polymer comprising a fluoropolymer dispersed in an organic medium comprising a primary solvent and a co-solvent, wherein the primary solvent comprises butyl pyrrolidone, a trialkylphosphate, 3-methoxy-N,N-dimethylpropanamide, 1,2,3-triacetoxypropane, or combinations thereof, and the co-solvent comprises ethyl acetoacetate, gamma-butyrolactone, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol monopropyl ether, diethylene glycol monobutyl ether, ethylene glycol monohexyl ether, or combinations thereof; and
(c) an adhesion promoter.
2 . The slurry composition of claim 1 , wherein the adhesion promoter comprises a polyvinylidene fluoride copolymer.
3 . The slurry composition of claim 2 , wherein the polyvinylidene fluoride copolymer comprises constitutional units comprising the residue of vinylidene fluoride and at least one of:
(i) (meth)acrylic acid; or
(ii) hydroxyalkyl (meth)acrylate.
4 . The slurry composition of claim 3 , wherein the (meth)acrylic acid comprises acrylic acid.
5 . The slurry composition of claim 3 , wherein the hydroxyalkyl (meth)acrylate comprises a C 1 to C 5 hydroxyalkyl (meth)acrylate.
6 . The slurry composition of claim 5 , wherein the C 1 to C 5 hydroxyalkyl (meth)acrylate comprises hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, or combinations thereof.
7 . The slurry composition of claim 1 , wherein the primary solvent comprises triethylphosphate, and the co-solvent comprises ethyl acetoacetate.
8 . The slurry composition of claim 1 , wherein the organic medium has a temperature at which the fluoropolymer disperses and an evaporation rate less than 10 grams per square meter per minute, at that temperature.
9 . The slurry composition of claim 8 , wherein the organic medium has an evaporation rate greater than 80 grams per square meter per minute, at 180° C.
10 . The slurry composition of claim 1 , further comprising an electrically conductive agent.
11 . The slurry composition of claim 10 , wherein the electrically conductive agent comprises graphite, acetylene black, furnace black, graphene, carbon nanotubes, or combinations thereof.
12 . The slurry composition of claim 10 , wherein the electrically conductive agent comprises carbon nanotubes.
13 . The slurry composition of claim 10 , wherein the electrically conductive agent comprises conductive carbon material having a surface area of 100 m 2 /g to 1000 m 2 /g.
14 . The slurry composition of claim 1 , wherein the slurry is substantially free of isophorone.
15 . The slurry composition of claim 1 , wherein the slurry is substantially free of N-methyl-2-pyrrolidone.
16 . A slurry composition comprising:
(a) an electrically conductive agent;
(b) a binder comprising a polymer comprising a fluoropolymer dispersed in an organic medium comprising a primary solvent and a co-solvent, wherein the primary solvent comprises butyl pyrrolidone, a trialkylphosphate, 3-methoxy-N,N-dimethylpropanamide, 1,2,3-triacetoxypropane, or combinations thereof, and the co-solvent comprises ethyl acetoacetate, gamma-butyrolactone, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol monopropyl ether, diethylene glycol monobutyl ether, ethylene glycol monohexyl ether, or combinations thereof; and
(c) 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 1 .
18 . An electrical storage device comprising:
(a) the electrode of claim 17 ;
(b) a counter electrode; and
(c) an electrolyte.
19 . The electrical storage device of claim 18 , wherein the electrical storage device comprises a cell, a battery pack, a secondary battery, a capacitor, or a supercapacitor.