Conformal Coating of Heterogeneous CoO/Co Nanocomposites on Carbon Nanotubes as Efficient Bifunctional Electrocatalyst for Li-Air Batteries. (20th November 2016)

• Record Type: Journal Article
• Authors: Liu, Ying; Liu, Yan; Cheng, Samson Ho-Sum; Yu, Sichen; Nan, Bo; Bian, Haidong; Md, Kamruzzaman; Wang, Man; Chung, C.Y.; Lu, Zhou-Guang
• Is Part Of: Electrochimica acta. Volume 219(2016)
• Page Start: 560
• Page End: 567
• Publication Date: 2016-11-20
• Subjects: Cobalt oxide -- Carbon nanotube -- Oxygen reduction reaction -- Oxygen evolution reaction -- Li-air battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.10.064
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Heterogeneous CoO/Co nanocomposites supported on CNTs electrocatalyst are synthesized. CNTs@CoO/Co electrode exhibits higher catalytic activity in a simulated air environment (80%Ar: 20% O2 ). CNTs@CoO/Co electrode shows a dramatic reduction of charge voltage overpotentials (0.39 V) and good cycling stability (110 cycles). The enhanced electrochemical performance is ascribed to the synergistic effect of CTNs and CoO/Co. Abstract: The effective design of noble-metal-free electrocatalysts is critical for improving the stability and cyclability of Li-air batteries. In this report, CoO/Co nanoparticles are conformally decorated on the surface of CNTs by a facile chemical bath deposition followed by thermal annealing. In a simulated air environment, Li-air battery with the CNTs@CoO/Co electrocatalyst exhibits a dramatic reduction of charge voltage overpotentials (0.39 V) and good cycling stability (110 cycles) as compared with that made with bare CNTs. The superior electrochemical performances are ascribed to the prior and strong absorption of LiO2 on the surface of CoO/Co, which can alleviate the formation of side-products, then leading to a decreased overpotential. The synergistic effect between CoO/Co and CNTs can also provide more catalytic sites for the ORR/OER, promoting the formation/decomposition reversibility of Li2 O2 . These results confirm that the CNTs@CoO/Co electrode can be a promising electrocatalyst for Li-air batteries.