Self-supported SnO₂ nanowire electrodes for high-power lithium-ion batteries

We propose a promising synthetic technique, which we term 'self-supported nanostructuring', for the direct growth of one-dimensional, SnO₂ nanowires on the current collector. The technique is based on a vapor-liquid-solid (VLS) mechanism via thermal evaporation at low synthetic temperature (600 °C). The as-synthesized SnO₂ nanowire electrode did not have any buffer layer prior to the nanowire evolution, and exhibited a single crystalline phase with highly uniform morphology and a thin diameter ranging from 40 to 50nm with a length of more than 1 μm. The SnO₂ nanowire electrode demonstrated stable cycling behaviors and delivered a high specific discharge capacity of 510mAhg^-1, even at the 50th cycle, which exceeded that of SnO₂ nanopowder and Sn nanopowder electrodes. Furthermore, the SnO₂ nanowire electrode displayed superior rate capabilities with a rechargeable discharge capacity of 600mAhg^-1 at 3C (where 1C = 782mAg^-1), 530mAhg^-1 at 5C, and 440mAhg^-1 at 10C. Our results support the potential opportunity for developing high-performance Li-ion batteries based on Li-alloying anode materials in terms of high-power density and high-energy density.