METHOD FOR MANUFACTURING NONAQUEOUS ELECTROLYTE FOR LITHIUM ION SECONDARY BATTERY AND METHOD FOR MANUFACTURING LITHIUM ION SECONDARY BATTERY USING THE NONAQUEOUS ELECTROLYTE

The present disclosure provides a method for manufacturing a nonaqueous electrolyte capable of reducing the increase in electric resistance of a lithium ion secondary battery reusing an electrode. The method for manufacturing a nonaqueous electrolyte for a lithium ion secondary battery herein disclosed includes the steps of: mixing a prescribed organic solvent and a support electrolyte; and immersing a positive electrode active material, which has been previously subjected to a charging treatment as a positive electrode active material of a lithium ion secondary battery, in a mixed solution obtained by such mixing.