Nickel/metal hydride storage battery

摘要

The present invention provides a nickel/metal hydride storage battery using improved nickel hydroxide with an increased energy density as the active material. This invention is characterized in that the nickel hydroxide as the active material of the positive electrode constituting the battery indispensably contains as a solid solution at least one transition metal selected from the group consisting of Mn, Cr and Co in a proportion of 2 to 20 atomic % based on the amount of the nickel hydroxide in terms of metallic nickel, and that the crystal structure of the nickel hydroxide at charged state is a hexagonal or tetragonal system which has a diffraction peak of 2&thetas; on (00 l ) plane of beta -NiOOH at an angle of approximately 15 DEG to 19 DEG in X-ray diffraction using CuK alpha as a source and has a regular array with a NaCl type structure.