Three-dimensional self-supported CuCo2O4 nanowires@NiO nanosheets core/shell arrays as an oxygen electrode catalyst for Li-O-2 batteries

Abstract

Developing rechargeable Li-O-2 batteries is an effective way to relieve current energy stress and electricity shortage. Designing an oxygen electrode catalyst with superior bifunctional catalytic activity can significantly improve the performance of Li-O-2 batteries. In this study, unique CuCo2O4 nanowires@NiO nanosheets core/shell arrays are directly synthesized on carbon cloth (CC) through a facile hydrothermal and electrochemical deposition. The one-dimensional CuCo2O4 nanowires have good electrical conductivity and a short transmission path to overcome sluggish kinetic processes. The two-dimensional NiO nanosheets can promote the easier formation and decomposition of Li2O2. The CuCo2O4@NiO/CC electrode can run 181 cycles with the capacity limit of 500 mA h g(-1) at 0.2 mA cm(-2), much higher than the CuCo2O4 electrode (107 cycles) and can exhibit the discharge capacity of 10 843 mA h g(-1) at 0.1 mA cm(-2), as well as better rate performance than CuCo2O4 electrode. Thus, the three-dimensional self-supported CuCo2O4 nanowires@NiO nanosheets core/shell arrays can take full advantage of each chemical component, provide more effective space for Li+ and O-2 diffusion and Li2O2 storage, and possess better electrical conductivity.