SECONDARY BATTERY, ELECTRONIC DEVICE, AND POWER TOOL

Provided is a battery capable of maintaining electrical insulation between a battery lid and a battery can when exposed to an aqueous solution such as sea water. Disclosed is a secondary battery including an electrode winding body in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked with a separator interposed between the electrodes and wound, an electrolytic solution, and a battery can that houses the electrode winding body and the electrolytic solution, the battery can having an opening hermetically sealed by a safety valve mechanism and a battery lid with a gasket interposed therebetween, in which the battery lid includes a terminal portion and a flange portion, and a metal layer is included between an outer main surface of among main surfaces of the flange portion and the gasket.