Influence of carbon on electrode properties of V–Ti–Ni type hydrogen storage alloy

Influences of carbon on microstructure and electrode properties were investigated for battery alloy V 4 TiNi 0.65 Co 0.05 Nb 0.047 Ta 0.047 . With increasing carbon concentration, the cycle-life of charge/discharge became longer. One of main factors that affected the cycle-life was the expansion and reduction of the (Ti,V)-based solid solution phase. Cracks yielded in TiNi phase more easily than in other phases. V-based battery alloys were more hardly pulverized than AB 5 and AB 2 intermetallic compound type materials.