Patent ID: 6699617
Filing Date: 2004-03-02
Classification: B22F,C01B,C22C,H01M,Y02E,Y02P,Y10S

Abstract:
A method for producing a hydrogen-absorbing alloy electrode, the hydrogen-absorbing alloy comprising hydrogen-absorbing alloy powders, the method comprising:a grinding step of grinding a hydrogen-absorbing alloy comprising at least one rare earth element, nickel and at least one transition metal element to produce said hydrogen-absorbing alloy powders, wherein surface portions of the hydrogen-absorbing alloy powders have an exposed nickel-condensed layer and are porous, and the content of the pores having a pore diameter of 1.5-2.0 nm in the surface portion of the alloy powders is 1.5Ã—10âˆ’3 to 4.0Ã—10âˆ’3 cc per 1 g of the alloy powders; a first treating step of treating the hydrogen-absorbing alloy powders with an alkaline aqueous solution; a second treating step of treating the hydrogen-absorbing alloy powders with an acidic aqueous solution in which the grinding step is wet grinding and the second treating step is carried out in succession to the first treating step, wherein the second treating step follows the first treating step, and the first treating step follows the grinding step; and forming a hydrogen-absorbing alloy electrode having said hydrogen-absorbing alloy powders therein.