Design and Synthesis of novel CuxGeOy/Cu/C nanowires by in situ chemical reduction process with highly reversible capacity for Lithium Batteries

The synthesis and use of ternary metal oxides/metal particles/carbon hybrids, especially 1D naowires composed of MGeO3/M/C hybrids for energy storage, remains very few reports. In this work, 1D CuxGeOy/Cu/C NWs (x < 1, y < 3) were successfully prepared by a simple method involving chemical reduction process and simultaneous carbon coating. It was found that through the polydopamine(PDA)-assisted chemical reduction process performed on the CuGeO3 NWs, the phase partially transformed to a mixture of crystalline Cu (∼70 nm) and amorphous CuxGeOy NWs with carbon coating, but the nanowire-shaped morphology was maintained. Electrochemical measurements showed that the CuxGeOy/Cu/C NWs exhibited a stable reversible capacity of ∼900 mA h g−1after 100 cycles. Even at 800 mA g−1, it also exhibited excellent high rate capacity of 350 mA h g−1. The newly generated CuxGeOy@Cu@CNWs exhibit enhanced cycle stability with high lithium-storage capability compared to that of the as-preparedCuGeO3NWs. (*) The in situ-synthesized Cu nanoparticles, amorphous state and carbon coating might play an important role in activating and enhancing the reversibility of the conversion reaction of CuxGeOy. In addition, this effective synthetic method might provide the methodology for the development of other ternary metal oxides/metal particles/carbon hybrids materials for energy storage.