LITHIUM ION SECONDARY BATTERY AND METHOD FOR MANUFACTURING SAME

摘要

The purpose of the present invention is to provide: a lithium ion secondary battery which is capable of improving the battery capacity without lowering the reliability due to an electrode film that has a protective layer exhibiting high adhesion to the electrode film; and a method for manufacturing the lithium ion secondary battery. The present invention provides a lithium ion secondary battery which is characterized by comprising: an electrode film that is formed on the surface of a collector foil and contains a binder that bonds the electrode film to the collector foil; and a protective film that is formed on the surface of the electrode film and contains insulating particles and a binder that bonds the protective film to the electrode film. This lithium ion secondary battery is also characterized in that the electrode film-side binder concentration in the protective film is higher than the binder concentration on the reverse side of the electrode film.