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

Abstract

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 degrees 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 50 nm with a length of more than 1 mu m. The SnO2 nanowire electrode demonstrated stable cycling behaviors and delivered a high specific discharge capacity of 510 mA h g(-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 600 mA h g(-1) at 3 C (where 1 C = 782 mA g(-1)), 530 mA h g(-1) at 5 C, and 440 mA h g(-1) at 10 C. 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.