Patent ID: 8916289

Claim:
An electrochemical element, comprising: a container including a side wall defining a cavity and an outer surface, wherein the side wall has an upper end portion, where the upper end portion defines an opening, a metal film is formed on the upper end portion, a pair of external terminals are formed on the outer surface and the metal film is electrically connected to one of the pair of external terminals; a sealing plate sealing the cavity of the container along the upper end portion of the side wall, where a brazing material is placed on the sealing plate, and the container is sealed with the sealing plate by welding a portion of the brazing material on the sealing plate and a portion of the metal film of the container which make contact with each other together in a state where a first electrode active material, a separator, a second electrode active material and an electrolyte are contained in the container; and an electricity collector sheet placed to close the opening defined by the container, which is formed integrally with the second electrode active material, where the electricity collector sheet includes an extending portion that extends onto the upper end portion of the side wall of the container so that the container and the sealing plate are welded together with the extending portion with the extending portion held between the sealing plate and the metal film on the upper end portion, wherein the electricity collector sheet is configured to be separated from the sealing plate before the container and the sealing plate are welded.