Nickel-hydrogen storage battery and battery pack

摘要

There is provided a nickel-metal hydride storage battery with suppression of rise in internal pressure, allowing suppression of alkaline electrolyte leakage even when two or more of the batteries are used. The battery includes: positive and negative electrodes; a separator interposed therebetween; and an alkaline electrolyte. The negative electrode includes: a material mixture layer including hydrogen storage alloy powder capable of electrochemically absorbing and releasing hydrogen; and a water-repellent layer including a first polymer including tetrafluoroethylene as monomer units, formed on the material mixture layer. The separator includes: a primary layer having a non-woven fabric structure of fibers; and a composite layer formed on the primary layer and being in contact with the water-repellent layer. The composite layer includes: fibers in continuity with the non-woven fabric structure; and a second polymer including tetrafluoroethylene as monomer units. The composite layer has a water contact angle of 10 to 80°.