Abstract:

The AB_5 alloy powders prepared by gas-atomization have many advantages: spherical particles convenient for packing. high press and wear resistance, enhanced corrosion and dispersion resistance. But lack of electrochemical activity is a barrier for use in Ni-MH battery. An activation method have been carried out in our laboratory. The gas-atomized powder was treated by an oxidizer (a solution of copper salt) to form a Cu and Ni-rich layer on the surface of the particles. The activity of the gas-atomized powder was greatly improved. For the treated powder MINi3.8Co0.5Mn0.3Al0.4, it was found that the discharge capacity after 3 cycles of charge-discharge reached an ideal value 240mA.h.g- 1, but only 103 mA•h•g- 1 for the non-treated powder.

Key words: Surface treatment, Metal hydride electrode