Electrochemical performance of Ni (–220) composites prepared by mechanical grinding

The effect of Ni amount on the overall electrochemical performance of CeMg 12 + x wt % Ni ( x = 180 – 220 ) composites has been investigated systematically. The results show that Ni amount introduced during ball-milling has a striking effect on the overall electrochemical properties. The maximum discharge capacity increases first and then decreases again with the increment of Ni amount, and the cycling stability generally improves with the Ni amount increment except for CeMg 12 + 200 wt % Ni composite, whose cycling retention rate is the lowest. And the high rate dischargeability increases with increasing Ni amount, which may be under a mixed control of charge transfer reaction on the surface and hydrogen diffusion in the alloy bulk.