Method for producing slurry for nonaqueous battery electrodes

1. A method of producing a slurry for a nonaqueous battery electrode, wherein the slurry comprises

a binder composition comprising an aqueous medium and a binder for a nonaqueous battery electrode;

a conductive auxiliary agent; and

an active material,

the method comprising:

a dispersing step of dispersing the conductive auxiliary agent in the binder composition;

a mixing step of mixing the conductive auxiliary agent-containing binder composition obtained in the dispersing step with the active material,

wherein in the conductive auxiliary agent-containing binder composition, a particle diameter at which particles begin to appear, which is measured according to the degree of dispersion by the JIS K5600-2-5 grain gauge method, is 90 μm or less;

the binder for the nonaqueous battery electrode is a copolymer (P) of a monomer mixture (M) which comprises a water-soluble ethylenically unsaturated monomer (A) and a (meta)acrylate salt monomer (B);

an amount of structure derived from the water-soluble ethylenically unsaturated monomer (A) is 0.5 to 50.0% by mass in the copolymer (P);

an amount of structure derived from the monomer (B) is 50.0 to 99.5% by mass in the copolymer (P); and

the monomer mixture (M) comprises no ethylenically unsaturated monomer having an amino group.

2. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 ,

wherein the water-soluble ethylenically unsaturated monomer (A) has at least one hydrophilic substituent selected from the group consisting of an amide bond, a sulfo group and a salt thereof, a hydroxy group, a carboxy group, a phosphate group and a salt thereof, a glycidyl group, an alkoxysilyl group and a polyoxyalkylene group.

3. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 ,

wherein the water-soluble ethylenically unsaturated monomer (A) comprises an amide bond.

4. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein the water-soluble ethylenically unsaturated monomer (A) is a monomer represented by general formula (1),

wherein, R 1 and R 2 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; and

an amount of structure derived from the water-soluble ethylenically unsaturated monomer (A) based on the copolymer (P) is 0.5 to 20.0% by mass.

5. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein the water-soluble ethylenically unsaturated monomer (A) is N-vinylformamide or N-vinylacetamide.

6. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein in the copolymer (P),

an amount of structure derived from the water-soluble ethylenically unsaturated monomer (A) is 0.5 to 40.0% by mass; and

an amount of structure derived from the monomer (B) is 60.0% to 99.5% by mass.

7. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein a weight average molecular weight of the binder for a nonaqueous battery electrode is in the range of 1,000,000 to 20,000,000.

8. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein the active material is a negative electrode active material.

9. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein an amount of the binder in the slurry for the nonaqueous battery electrode is 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the active material.

10. The method of producing the slurry for the nonaqueous battery electrode according to claim 1 , wherein the nonaqueous battery is a lithium ion secondary battery.

11. A method for producing a nonaqueous battery electrode, the method comprising:

applying the slurry for the nonaqueous battery electrode obtained by the method according to claim 1 onto a surface of a current collector, and

drying the slurry for a nonaqueous battery electrode.

12. A method of producing a nonaqueous battery, the method comprising:

housing the nonaqueous battery electrode obtained by the method of claim 11 and an electrolyte solution in an exterior body.