Patent ID: 8293419

Claim:
A method for preparing a hydrogen absorbing electrode, comprising the steps of: immersing a hydrogen absorbing alloy powder which contains a rare earth element as an alloy constituent and a transition metal element in an aqueous alkaline solution so that the saturation mass susceptibility is 1.0 to 6.5 emu/g of said hydrogen absorbing alloy thereby obtaining an immersion treatment solution, removing the immersion treatment solution from said hydrogen absorbing alloy powder through said immersing step by a filtration, peeling hydroxides of the rare earth elements deposited on a surface of said hydrogen absorbing alloy powder from said hydrogen absorbing alloy powder through said removing step, separating and removing said hydroxides of the rare earth elements from said hydrogen absorbing alloy powder through said peeling step by utilizing differences of sedimentation speeds of hydrogen oxides of the rare earth elements and said hydrogen absorbing alloy powder in the aqueous solution, mixing said hydrogen absorbing alloy powder through said separating and removing step with an oxide or hydroxide of a rare earth element wherein said oxide or hydroxide has as a main component at least one element selected from the group consisting of Dy, Ho, Er, Tm, Yb, and Lu, and applying a mixture of said hydrogen absorbing alloy powder and said oxide or hydroxide of said rare earth element in a form of powder whose average diameter is equal to or less than 5 μm to form a desired shape.