一种新型硅碳复合薄膜材料作为锂离子二次电池负极材料的研究

利用气相沉积技术,制备了SixCy层和C层相间的硅碳复合薄膜材料。XRD测试和Raman光谱测试表明,该硅碳复合薄膜材料具有纳米微晶结构。电化学性能测试表明,该SixCy/C复合薄膜材料,具有较低的充放电平台(0·5V以下),对应的首次放电容量达1200mAh/g以上,经过200次循环,容量保持率高于85%。SixCy/C复合薄膜材料性能的改善,主要原因可能源于活性材料Si中的缓冲骨架以及碳的共同作用,它们的存在改善了复合材料的导电性能,也有效缓冲了在充放电过程中活性组分Si所导致的体积变化。

A Novel Silicon/Carbon Composite Film as Anode Material for Lithium-Ion Secondary Battery

Silicon-carbon composite film was prepared with vapor deposition technology. The measurements of XRD and Raman spectroscopy indicate that the Si_xC_y/C composite film has nano-microcrystalline structure. The results of electrochemical test indicate that the Si_xC_y/C composite film deposited on Cu foil has low plateau during charge and discharge (below 0.5V vs.Li~ /Li), the corresponding discharge capacity reaches 1200mAh/g, and the capacity retention is 85% after 200 cycles. The improvement of the electrochemical performance of the Si_xC_y/C composite film contributes to the buffer framework and doping C element, which improves the conductivity of the composite and effectively buffer the volume change induced by Li insertion/extraction.