| abstract |
An object of the present application is to provide a secondary battery which uses a sulfur-based active material as a negative electrode active material, suppresses the reaction of eluted polysulfides with a positive electrode phase, and has excellent cycle characteristics. The solution of the present application lies in a metal ion secondary battery, which comprises a negative electrode having a sulfur-containing compound as a negative electrode active material, a positive electrode and an electrolyte, and a polymer gel layer is provided on the surface of the positive electrode. |