Remarkable Enhancement in Electrochemical Performances of La-Mg-Ni-based Alloy Decorated with the Reduced Graphene Oxide Supported Cobalt

• Published in: International journal of electrochemical science 2020-08, Vol.15 (8), p.7483-7492
• Main Authors: Huang, Dongyuan, Wei, Bing, Qing, Peilin, Zhou, Wenzheng, Liu, Haizhen, Guo, Jin, Lan, Zhiqiang
• Format: Article
• Language: English
• Subjects: Battery; Dynamics; Electrochemical performance; Graphene; Rare earths
• ISSN: 1452-3981; 1452-3981
• DOI: 10.20964/2020.08.26

A reduced graphene oxide supported cobalt (Co@G) was synthesized via a wet-chemical method and was then introduced into a La0.7Mg0.3 (Ni0.85Co0.15) 3.5 alloy (designated as La-Mg-Ni) by means of mechanical alloying. Experimental results indicated that the La-Mg-Ni alloy electrodes decorated with Co@G nanocomposites exhibited excellent electrochemical performance. At a discharge current density of 1200 mA/g, the high rate dischargeability (HRD1200) of the undecorated alloy electrode was 59.8%. This value increased to 82.3%, 84.7%, and 70.7%, respectively, when the alloy electrode was decorated with x wt.% (x=3,6,9) Co@G nanocomposites, respectively. The exchange current density (I0) and the limiting current density (Il) were also enhanced under the catalytic action of the Co@G nacocomposites. The electrode decorated with the 6.0 wt.% Co@G nanocomposite exhibited the best electrochemical performance. The improvements in electrochemical performance of the La-Mg-Ni alloy electrodes are attributed to the synergistic catalytic action of graphene and Co, thereby facilitating the electron transport and shortening the ion transportation paths in the alloy electrodes.