Studies on electrochemical performance of transition metal boride alloys

Precursors of transition metal borides were synthesized by a chemical reduction method. The precursors were heat-treated at 50°C and 300°C, respectively to get Co-B, Ni-B, and Ni-Co-B alloys. The prepared samples showed good electrochemical performance in aqueous KOH solution. At constant current density of 30 mA/g, Co-B and Ni-B alloys which were heat-treated at 50°C could achieve discharge capacity of 310 mAh/g and 103 mAh/g, respectively. For Co doped Ni-Co-B alloys, not only B, but also Ni could be activated. Ni-Co-B alloys had much higher discharge capacity than Ni-B alloys. The Ni-Co-B alloy heat-treated at 300°C could achieve discharge capacity of 258 mAh/g, close to those of Co-B alloys.