Hydrothermal synthesis of peony-like CuO micro/nanostructures for high-performance lithium-ion battery anodes

The peony-like CuO micro/nanostructures were fabricated by a facile hydrothermal approach. The peonylike CuO micro/nanostructures about 3 -5 μm in diameter were assembled by CuO nanoplates. These CuO nanoplates, as the building block, were self-assembled into multilayer structures under the action of ethidene diamine, and then grew into uniform peony-like CuO architecture. The novel peony-like CuO micro/nanostructures exhibit a high cycling stability and improved rate capability. The peony-like CuO micro/nanostructures electrodes show a high reversible capacity of 456 mAh/g after 200 cycles, much higher than that of the commercial CuO nanocrystals at a current 0.1 C. The excellent electrochemical performance of peony-like CuO micro/nanostructures might be ascribed to the unique assembly structure, which not only provide large electrode/electrolyte contact area to accelerate the lithiation reaction, but also the interval between the multilayer structures of CuO nanoplates electrode could provide enough interior space to accommodate the volume change during Li⁺ insertion and de-insertion process.