Effect of Ni content on the electrochemical performance of the ball-milled La2Mg17−xNix + 200 wt.% Ni (x = 0, 1, 3, 5) composites

The effect of Ni content on the electrochemical properties of the ball-milled La2Mg17−xNix + 200 wt.% Ni (x = 0, 1, 3, 5) composites was investigated systematically. The electrochemical results reveal that the maximum discharge capacity decreases with the increase of x value, but the cycling stability is just on the contrary. The cycle life improves with the increase of x value, which can be confirmed by the XRD results of the ball-milled composite after 20 cycles. And the high-rate dischargeability of the composite electrodes first increases and then decreases with increasing Ni content, and the ball-milled La2Mg16Ni + 200 wt.% Ni composite electrode exhibits the best electrochemical kinetics. In addition, the electrochemical kinetic parameters study, including the polarization resistance Rp, the exchange current density I0 and the limiting current density Il, also confirm this result.