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

• Published in: Journal of rare earths Vol. 37; no. 12; pp. 1312 - 1319
• Main Authors: Huang, Xiantun, Lan, Zhiqiang, Li, Jiacheng, Zhang, Hao, Guo, Jin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2019
• Subjects: Alloy electrode; Electrochemical properties; Graphene; Kinetic properties; Rare earths; Kinetic properties; Electrochemical properties; Graphene; Rare earths; Alloy electrode
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/j.jre.2019.06.003

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 × 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%Cu@rGO nanocomposite not only increases the electrochemical capacity of La0.7Mg0.3Ni2.8Co0.5 alloy electrodes, but also improves their electrochemical kinetic properties. The electrochemical kinetics of the La0.7Mg0.3Ni2.8Co0.5 alloy electrodes can be enhanced by adding Cu@rGO nanocomposite, and the La0.7Mg0.3-Ni2.8Co0.5+6 wt%Cu@rGO electrode shows an excellent comprehensive electrochemical properties. [Display omitted]