US Patent 7223496 Electrochemical element

An electrochemical element having a metal case for accommodating an element unit in which a positive electrode and a negative electrode are disposed to face each other with a separator between them, and an electrolyte; a sealing body for sealing an opening of the metal case; and a sealant provided between the metal case and the sealing body, wherein the sealant comprises an elastomer as a main component and an organic pigment and is colored in a color different from the metal case and sealing body. The present invention also includes an electrochemical element which further has a gasket interposed between the sealing body and the metal case, and in which the sealant is provided between the gasket and the sealing body or the metal case.