Hydrogen storage and electrode properties of V-based solid solution type alloys prepared by a thermic process

A vanadium-based solid-solution-type alloy V4TiNi0.65Co0.05Nb0.047Ta0.047 with a large discharge capacity was obtained using a low-cost precursor of V4Ni0.65Nb0.047 produced by aluminothermic reduction from V2O5, Nb2O5, and Ni. The alloy was deoxidized to a low level by adding mischmetal as a reducing agent when the precursor was alloyed with Ti, Co, and Ta. The alloy showed a hydrogen absorption behavior similar to an alloy prepared from high-purity constituent metals. Moreover, the Mm-Ni-O phase was precipitated as spherical particles along the TiNi network phase in the alloy, remarkably improving the electrode rate capability because of enhanced catalytic ability of the network phase. (C) 2000 The Electrochemical Society. S0013-4651(00)03-055-X. All rights reserved.