Slurry composition for lithium ion electrical storage devices

Abstract

The present invention is directed to a lithium ion battery electrode slurry composition comprising: (a) an electrochemically active material capable of lithium intercalation and deintercalation; (b) a binder dispersed in an aqueous or organic medium and comprising a reaction product of a reaction mixture comprising one or more epoxy functional polymer(s) and one or more acid functional acrylic polymer(s); and (c) an electrically conductive agent. The present invention also provides an electrode comprising: (a) an electrical current collector; and (b) a cured film formed on the electrical current collector. The cured film is deposited from the slurry composition described above. Electrical storage devices prepared from the electrode are also provided.

What is claimed is: 
     
         1 . A lithium ion battery electrode slurry composition comprising:
 (a) an electrochemically active material capable of lithium intercalation and deintercalation;   (b) a binder comprising:
 (i) a crosslinking agent comprising an aminoplast, and 
 (ii) a reaction product of a reaction mixture comprising one or more epoxy functional polymer(s) and one or more acid functional acrylic polymer(s); and 
   (c) an electrically conductive agent.   
     
     
         2 . The electrode slurry composition of  claim 1 , further comprising a thickener. 
     
     
         3 . The electrode slurry composition of  claim 1 , wherein the binder (b) is dispersed in an aqueous medium. 
     
     
         4 . The electrode slurry composition of  claim 3 , further comprising an organic solvent. 
     
     
         5 . The electrode slurry composition of  claim 1 , wherein the binder (b) is dispersed in an organic medium. 
     
     
         6 . The electrode slurry composition of  claim 1 , wherein the crosslinking agent further comprises a polycarbodiimide, a polyepoxide, or a combination thereof. 
     
     
         7 . The electrode slurry composition of  claim 1 , wherein the electrochemically active material (a) comprises LiCoO 2 , LiNiO 2 , LeFePO 4 , LiCoPO 4 , LiMnO 2 , LiMn 2 O 4 , Li(NiMnCo)O 2 , Li(NiCoAl)O 2 , carbon-coated LiFePO 4 , graphite, silicon compounds, tin, tin compounds, or a combination thereof. 
     
     
         8 . The electrode slurry composition of  claim 1 , wherein the electrically conductive agent (c) comprises graphite, acetylene black, furnace black, graphene or a mixture or combination of any of the foregoing. 
     
     
         9 . The electrode slurry composition of  claim 1 , wherein the slurry is substantially free of N-methyl-2-pyrrolidone. 
     
     
         10 . The electrode slurry composition of  claim 1 , wherein the electrochemically active material (a) is present in amounts of 70 to 98 percent by weight; the binder is present in amounts of 1 to 10 percent by weight; and the electrically conductive agent (c) is present in amounts of 1 to 20 percent by weight, the percentages by weight being based on the total weight of solids in the slurry. 
     
     
         11 . The electrode slurry composition of  claim 1 , wherein the binder (b) is substantially free of a polyvinylidene fluoride polymer. 
     
     
         12 . The electrode slurry composition of  claim 1 , wherein the binder comprises a reaction mixture comprising one or more epoxy functional polymers and one or more acid functional polymers, wherein the one or more epoxy functional polymers are prepared by reacting together a polyepoxide and (i) a polyamine group-containing material and/or (ii) a polyhydroxyl group-containing material. 
     
     
         13 . An electrode comprising:
 (a) an electrical current collector; and   (b) a cured film formed on the electrical current collector, wherein the film is deposited for a slurry composition comprising:
 (i) an electrochemically active material capable of lithium intercalation and deintercalation; 
 (ii) a binder dispersed in an aqueous or organic medium and comprising a reaction product of a reaction mixture comprising one or more epoxy functional polymer(s) and one or more acid functional acrylic polymer(s); and 
 (iii) an electrically conductive agent. 
   
     
     
         14 . The electrode of  claim 13 , wherein the slurry composition further comprises a thickener. 
     
     
         15 . The electrode of  claim 13 , wherein the thickener comprises a carboxymethylcellulose. 
     
     
         16 . The electrode of  claim 13 , wherein the electrical current collector (a) comprises copper or aluminum in the form of a mesh, sheet or foil. 
     
     
         17 . The electrode of  claim 13 , wherein the electrically conductive agent (iii) comprises graphite, acetylene black, furnace black, graphene or a mixture or combination of any of the foregoing. 
     
     
         18 . An electrical storage device comprising:
 (a) the electrode of  claim 13 ,   (b) a counter electrode, and   (c) an electrolyte.   
     
     
         19 . The electrical storage device of  claim 18 , wherein the electrolyte (c) comprises a lithium salt dissolved in a solvent. 
     
     
         20 . The electrical storage device of  claim 20 , wherein the lithium salt is dissolved in an organic carbonate.