Patent ID: 6593031
Filing Date: 2003-07-15
Classification: H01M,Y02E,Y02P,Y10S

Abstract:
A nickel metal-hydride cell comprising:a paste type nickel positive electrode containing nickel hydroxide and a cobalt conducting aid selected from the group consisting of metal cobalt and cobalt compounds, a negative electrode which comprises a hydrogen absorbing alloy having a composition of the formula: â€ƒMmNi5âˆ’x+yMx wherein Mm is a rare earth element containing at least La, M is a metal element containing at least Mn, x is a number larger than 0 and smaller than 2, and y is a number larger than âˆ’0.2 and smaller than 0.6, a separator interposed between the positive and the negative electrodes, and an electrolytic solution comprising an aqueous alkaline solution, in which a ratio of Câ€”H to Câ€”Co(II) is 1.3 or less, wherein Câ€”H is a quantity of electricity of a discharge reserve formed in the negative electrode, and Câ€”Co(II) is a quantity of electricity necessary for reducing cobalt oxide with a higher oxidation state in the positive electrode to cobalt(II) oxide.