Patent ID: 7758994
Filing Date: 2010-07-20
Classification: H01M,Y02E

Abstract:
1. A nickel-metal hydride storage battery comprising: a battery main part; and a case which houses the battery main part and forms a gas release hole through which gas in the case can be released from the case; and a safety valve device including further comprising: a valve member having a sealing surface, a flange, a top wall, and a cylindrical peripheral wall, the flange extending radially outward from a bottom portion of the cylindrical peripheral wall, the top wall and the cylindrical peripheral wall defining a space in-between the top wall and the case, and the valve member having a closed position wherein the sealing surface contacts a portion of the case around the gas release hole to close the hole, and an open position wherein when an inner pressure in the case exceeds a predetermined value, the sealing surface of the valve member separates from the portion around the hole to release gas from the case; and a valve cap having an outer peripheral wall and covering the valve member, and an aperture in the valve cap; wherein the valve member is made of a hydrogen gas permeable rubber, allowing hydrogen gas in the case to permeate through the valve member and leak out of the battery at a hydrogen leak rate V wherein the hydrogen leak rate V