Fabrication of all-solid-state lithium polymer secondary batteries using Al2O3-coated LiCoO2

A method to fabricate all solid-state lithium polymer secondary batteries (LPB) using Al2O3-coated LiCoO2 was discussed. The constant voltage impedance measuring method was used to determine the degradation magnitude of batteries at high voltage where the cell maintains required voltage. The method enabled interfacial resistance separation in the LPB. It was observed that the intervening alumina might have prevented interfacial degradation, resulting in the stability of both electrolyte and cathode active material.