PERFORMANCE OF AB, ALLOYS FOR HYDROGEN STORAGE AND HYDRIDE ELECTRODES

Two types of hydride electxodes are potential candidates to replace the Cd elecsode in NilCd batteries, One is of the A type where A is a rare earth metal or mixture thereof, and B is the transition metal. The other is commonly referred to as A type. A , type alloys with partial substitution of the B element in A type hydride material (Ovonic) with Co, Mn, Al, and Fe were studied (A components were Ti and Zr, the major B components were V, Ni, and Ck), The materials were prepared by arc melting and characterized using X-ray diffraction and SEM techniques. The hydrogen absorptionldesorption presswe-composition isothems for the alloys were determined, Partial substitution of the B element changes the initial, multiphase structure of the basic composition. Mn increases the plateau pressure, while addition of small amounts of A1 and Fe have positive influence. Generally, the addition of described elements does not improve the characteristics of the basic material (Ovonic). The electrochemical storage capacities of based system were in the range of 300-400 mAh/g.