ADJUSTING METHOD OF NON-AQUEOUS ELECTROLYTIC SOLUTION AND PRODUCING METHOD OF LITHIUM-ION SECONDARY BATTERY WITH REUSED ELECTRODE PLATE

There is provided a method of adjusting non-aqueous electrolytic solution achieving reduction in an amount of hydrofluoric acid included in the non-aqueous electrolytic solution and a method of producing a lithium-ion secondary battery with a reused electrode plate by producing a lithium-ion secondary battery having less IV resistance with a reused electrode plate. Nonaqueous electrolytic solution includes Li salt containing element fluorine. This non-aqueous electrolytic solution is brought into contact with a basic Li compound to form a pH-level-adjusted non-aqueous electrolytic solution which has been adjusted its pH level within a range of 6 to 8 inclusive.