Nickel-hydrogen storage battery

In a nickel-metal hydride storage cell, deterioration of a cell capacity at high temperature and degradation of a cycle characteristic are suppressed. The nickel-metal hydride storage cell of the invention comprises in a cell case, a positive electrode comprising a positive electrode active material composed mainly of nickel hydroxide powder, a negative electrode comprising a negative electrode active material composed mainly of hydrogen-absorbing alloy powder, and a separator interposed between the positive and negative electrodes and impregnated with an electrolyte, the nickel-metal hydride storage cell characterized in that the negative electrode active material comprises a copper compound, the positive electrode comprises an aggregate of coated particles each in which a coating layer comprising a sodium-containing cobalt compound is formed on a surface of a nickel hydroxide particle, and the positive electrode active material is such that an oxide or hydroxide of one of bismuth, calcium, ytterbium, manganese, copper, scandium, and zirconium, is added to the aggregate of coated particles.