Effect of reduced graphene oxide-supported copper addition on electrochemical properties of La0.7Mg0.3Ni2.8Co0.5 electrodes

The reduced graphene oxide-supported copper (email protected]) nanocomposite was introduced to improve the electrochemical properties of La_0.7Mg_0.3Ni_2.8Co_0.5 alloy electrodes. Experimental results show that adding email protected] 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 email protected] nanocomposite also provides alloy electrodes with hydrogen diffusion coefficients of 3.7 × 10^?10 cm²/s (x = 0), 4.1 × 10^?10 cm²/s (x = 3), 4.2 × 10^?10 cm²/s (x = 6) and 4.0 × 10^?10 cm²/s (x = 9). Clearly, the addition of 6 wt%email protected] nanocomposite not only increases the electrochemical capacity of La_0.7Mg_0.3Ni_2.8Co_0.5 alloy electrodes, but also improves their electrochemical kinetic properties.