PRODUCING METHOD FOR LITHIUM-ION SECONDARY BATTERY

A producing method for a lithium-ion secondary battery includes a positive-electrode-plate producing step of producing a positive electrode plate having a positive active material layer on a surface of a positive current collecting foil, an electrode-body producing step of producing an electrode body provided with the positive electrode plate and a negative electrode plate, a housing step of housing the electrode body inside a battery case, an injecting step of injecting non-aqueous electrolytic solution into the battery case housed with the electrode body to produce an injection-completed battery, and an initial charging step of initially charging the injection-completed battery. The injecting step is to inject the non-aqueous electrolytic solution into the battery case housed with the electrode body in which a water content of the positive active material layer is 100 ppm or more.