Method of forming protective coating on cell safety valve element, cell safety valve element coated with protective film, cell sealing plate using the element, and enclosed cell using the plate

• Main Authors: SAIJO KINJI, SUGIMOTO YOSHIYUKI, OKAMOTO HIROAKI, KAWAMURA HIROAKI
• Format: Patent
• Language: English
• Published: 16.11.2004
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

A method of forming a protective coating on a cell safety valve element by coating the cell safety valve element with a protective film to protect metal portions thereof against corrosion, a cell safety valve element coated with a protective film, a cell sealing plate using the element, and an enclosed cell using the plate. The safety valve element comprises a coating (3) obtained by applying an organic paint onto at least one surface of the cell safety valve element (10) consisting of a metal base plate (1) having a through hole (4) drilled therein and a metal foil (2) laminated on the metal base plate (1) so as to block the through hole (4). The sealing plate is formed by bringing the cell safety valve element (10), on which a protective coating (3) comprising an organic resin film is formed, into contact with a cell exterior can sealing plate (6), in which the through hole (4) acting as a safety valve port is drilled so that the through hole (4) in the metal base plate of the cell safety valve element (10) and the through hole (7) in the sealing plate face each other and bonding the both at a portion around the through hole (7) in the sealing plate to form the cell sealing plate. The enclosed cell is formed by fitting and supporting the cell sealing plate at the inner periphery of an opening of the cell exterior can in which are housed an electrode body consisting of a positive electrode, a negative electrode and a separator together with an electrolyte to block the opening in the cell exterior can.