Method for manufacturing positive electrode of nonaqueous electrolyte secondary battery
View Patent ↗A method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery includes forming an inorganic particle slurry layer formed on a surface of a positive electrode active material layer. The method includes forming a positive electrode active material layer on a surface of a positive electrode collector, and coating an inorganic particle slurry containing inorganic particles and carboxymethyl cellulose on a surface of the positive electrode active material layer and thereafter drying the slurry to form a porous inorganic particle layer. The inorganic particle slurry contains carboxymethyl cellulose having an etherification degree of 0.8 or more and a viscosity of 800 mPa·s or more in a 1% aqueous solution at a ratio of 0.2% by mass or more and 1.0% by mass or less with respect to the inorganic particles.
1. A method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery, the method comprising:
forming a positive electrode active material layer on a surface of a positive electrode collector; and
coating an inorganic particle slurry containing inorganic particles, carboxymethyl cellulose, and a binder on a surface of the positive electrode active material layer and thereafter drying the slurry to form a porous inorganic particle layer,
the inorganic particle slurry containing carboxymethyl cellulose having an etherification degree of 0.8 or more and a viscosity of 800 mPa·s or more in a 1% aqueous solution at a ratio of 0.2% by mass or more and 1.0% by mass or less with respect to the inorganic particles.
2. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the inorganic particles include an insulating inorganic oxide.
3. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the inorganic particles include at least one of titanium oxide and aluminum oxide.
4. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the inorganic particle slurry includes a binder at a content of 5% by mass or less with respect to the inorganic particles.
5. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the porous inorganic particle layer has a thickness of 0.5 to 3.0 μm.
6. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the inorganic particle slurry is coated on the surface of the positive electrode active material layer by a gravure coating method.
7. The method for manufacturing a positive electrode for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the forming of the positive electrode active material layer on the surface of the positive electrode collector includes coating a positive electrode active material slurry on the surface of the positive electrode collector and thereafter drying the slurry, the positive electrode active material slurry is a dispersion slurry of a positive electrode active material in a nonaqueous solvent, and the inorganic particle slurry is a dispersion slurry of the inorganic particles in water.