Nickel metal hydride storage battery and battery pack

摘要

Provided is a nickel-metal hydride storage battery in which an increase in battery internal pressure is suppressed and leakage of an alkaline electrolyte can be suppressed even when a plurality of batteries are used. The nickel-metal hydride storage battery includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an alkaline electrolyte, and the negative electrode includes a hydrogen storage alloy powder capable of electrochemically storing and releasing hydrogen. A main layer having a mixture layer and a water repellent layer containing a first polymer containing tetrafluoroethylene as a monomer unit, formed on the surface of the negative electrode mixture layer, and the separator has a nonwoven fabric structure of fibers; A composite layer formed on the surface of the main layer and in contact with the water repellent layer, wherein the composite layer includes a fiber that is continuous with the nonwoven fabric structure, and a second polymer that includes tetrafluoroethylene as a monomer unit; The contact angle of the surface with respect to water is 10 to 80 °.