SHEET TYPE SECONDARY BATTERY

摘要

PURPOSE:To prevent the leakage of the electrolyte to elongate the life time of a secondary battery using an overcoating material made of a metal foil not making alloy with alkaline metals such as lithium coated with synthetic resin for at least the negative electrode. CONSTITUTION:An overcoating foil of a metal not making alloy with alkaline metals such as lithium e.g. stainless steel foil 1, instead of aluminum foil, is coated with an adhesive polypropylene layer 2 on the outside surface and an adhesive low density polyethylene base layer 3 on the inside surface and pressed and formed to a multilayer foil for the overcoating material A of the negative electrode. Thereby the leakage of the electrolyte of a sheet type secondary battery using an alkaline metal for the negative electrode can be prevented to elongate the life time.