US Patent 10461308 Sealed battery and method of manufacture

A sealed battery according to the disclosure includes: a case provided with a case body having an opening therein and a lid that is sized so as to be capable of closing the opening and that has an electrolyte fill port; an electrode assembly that is housed in the case; and an electrolyte solution. The lid is provided with a filler plug that is welded to the lid so as to close the fill port. The lid has an outside surface with a region thereon subjected to electrolyte-repelling treatment so as to surround the weld where the filler plug is welded.