METHOD FOR PRODUCING POSITIVE ELECTRODE ACTIVE MATERIAL LAYER FOR LITHIUM ION BATTERY, AND POSITIVE ELECTRODE ACTIVE MATERIAL LAYER FOR LITHIUM ION BATTERY

[PURPOSE] To provide a method for producing a positive electrode active material layer for a lithium ion battery that can improve the durability and internal resistance of a lithium ion battery, and particularly a lithium ion battery that operates at high voltage. [SOLUTION MEANS] The method for producing a positive electrode active material layer for a lithium ion battery according to the invention comprises coating a substrate with a positive electrode mixture slurry containing a positive electrode active material, a first lithium salt, a second lithium salt and a solvent, and drying off the solvent. In the present invention, the first lithium salt is lithium phosphate, the second lithium salt is selected from the group consisting of lithium carbonate, lithium hydroxide, lithium nitrate, lithium acetate, lithium sulfate and combinations thereof, and the proportion of the second lithium salt with respect to the first lithium salt is 1 to 50 mol% based on the number of lithium atoms.