Hierarchically Porous CuCo2O4 Microflowers: a Superior Anode Material for Li-ion Batteries and a Stable Cathode Electrocatalyst for Li-O2 Batteries

Hierarchical CuCo2O4 microflowers (CCFs) self-assembled by thin and porous nanosheets were synthesized by a simple solvothermal reaction followed by a low-temperature calcination. The porous nanosheets not only shorten the Li-ion diffusion distances and tolerate the volume variation upon cycling, but also enhance the transportation of oxygen and Li+ ions, and have abundance of active sites on the surface. Thus, it has been explored as the superior anode material in Li-ion batteries and as the cathode catalyst in Li-O-2 batteries. Both of applications exhibit the remarkable electrochemical properties. In lithium ion batteries, CuCo2O4 micro-flowers deliver a specific lithium storage capacity of 871 mA h g(-1), after 300 cycles at 100 mA g(-1). Even at a high rate of 1 A g(-1), the reversible capacity of the CuCo2O4 microflowers still remains at 612 mA h g(-1) after 500 cycles. In Li-O-2 batteries, CuCo2O4 microflowers as the cathode catalyst last 120 cycles, much longer than highly aggregated CuCo2O4 and pure carbon. (C) 2016 Elsevier Ltd. All rights reserved.