HYDROGEN STORAGE ELECTRODE AND NICKEL HYDROGEN BATTERY

摘要

A nickel hydrogen battery having excellent cycle characteristics, high-rate discharge characteristics and output characteristics can be obtained by forming a hydrogen storage electrode using a hydrogen storage alloy powder as the active material into an electrode which is excellent in corrosion resistance to an electrolyte solution and high-rate discharge characteristics. Specifically disclosed is a hydrogen storage electrode characterized by containing 0.3-1.5 parts by weight of an oxide or hydroxide of a rare earth element per 100 parts by weight of a hydrogen storage alloy powder mainly containing a rare earth element and a transition metal element and having a saturation magnetization per unit mass of 1.0-6.5 emu/g. The hydrogen storage electrode is also characterized in that the oxide or hydroxide of a rare earth element is a powder mainly containing one or more rare earth elements selected from Dy, Ho, Er, Tm, Yb and Lu and having an average particle diameter of not more than 5 µm. Also specifically disclosed is a nickel hydrogen battery wherein a nickel electrode is used as the positive electrode and the above-described hydrogen storage electrode is used as the negative electrode.