▎ 摘　　要

The reduced graphene oxide-supported copper (Cu@rGO) nanocomposite was introduced to improve the electrochemical properties of La0.7Mg0.3Ni2.8Co0.5 alloy electrodes. Experimental results show that adding Cu@rGO nanocomposite with mass fractions of x wt% (x = 0, 3, 6 and 9) to the alloy electrodes provides electrodes with maximum discharge capacities of 368.9 mAh/g (x = 0), 373.2 mAh/g (x = 3), 407.3 mAh/g (x = 6) and 398.6 mAh/g (x = 9), and high-rate dischargeabilities at a discharge current density of 1200 mA/g of 40.5% (x = 0), 64.0% (x = 3), 82.0% (x = 6) and 76.0% (x = 9). The addition of Cu@rGO nanocomposite also provides alloy electrodes with hydrogen diffusion coefficients of 3.7 x 10(-10) cm(2)/s (x = 0), 4.1 x 10(-10) cm(2)/s (x = 3), 4.2 x 10(-10) cm(2)/s (x = 6) and 4.0 x 10(-10) cm(2)/s (x = 9). Clearly, the addition of 6 wt%Cu@rGO nanocomposite not only increases the electrochemical capacity of La0.7Mg0.3Ni2.8Co0.5 alloy electrodes, but also improves their electrochemical kinetic properties. (C) 2019 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.