Patent ID: 9543559
Date: 2017-01-10
CPC Classifications: H01M,Y02E

Claim:
1. A square secondary battery which stores an electrode group in a battery case thereof, with the electrode group soaked with an electrolyte, the square secondary battery comprising: a case surface portion in which an injection opening for injecting the electrolyte into the battery case is opened; a sealing cap disposed in facing relation to the case surface portion at a position to close the injection opening, the sealing cap being welded at an outer circumferential edge thereof to the case surface portion, thereby sealing the injection opening; a pressure sensitive adhesive member interposed between the sealing cap and the case surface portion for securing the sealing cap to the case surface portion; and a gas passage formed between the case surface portion and the sealing cap, the gas passage communicating the injection opening with a gap in a gas permeable manner, the gap is positioned between the battery case and the sealing cap and downstream of the pressure sensitive adhesive member, wherein the pressure sensitive adhesive member is formed of double-sided tape adhered on both surfaces of a substrate wherein the substrate comprises a gas permeable layer that forms the gas passage.