PURPOSE: To make compact and lightweight a power supply for portable electronic equipment by using a carbonaceous material as a negative electrode active material allowing lithium ions to be doped and de-doped.

CONSTITUTION: A carbonaceous material as a negative electrode active material for a nonaqueous secondary battery is such that lithium ions can be doped and de-doped. For example, graphite, pyrocarbon, a baked body of organic polymer or the like is used as the carbonaceous material. A polyolefine single fine porous film such as polyethylene and polypropylene, or a film comprising one or more types of the materials as pasted is used as a separator. If necessary, positive and negative active material particles are applied to a metal foil collector, together with a binder and this collector is spirally wound about a cylindrical or elliptical body via the separator. This coil body is inserted in a battery can and fitted with a lead tap. Then, the body is impregnated with electrolytic solution and sealed. According to this construction, the battery can be made substantially compact.