锂离子电池硅/石墨复合负极材料的制备及性能研究

    Preparation and Properties of Silicon/Graphite Composites as Anode Materials for Lithium Batteries

    • 摘要: 锂离子电池发展的重要目标之一是高容量的负极材料,而硅材料以其高达4 200 mAh/g的理论比容量成为研究热点;但是硅负极材料有较大的体积效应,从而造成其电化学循环性能的快速下降,限制了其在生产中的应用.本研究以纳米硅与石墨不同比例的掺杂,通过高能球磨与退火处理,表明当硅与石墨比例为2:1时,首次放电比容量可达2 136.4 mAh/g,同时首次的充放电效率为85.5%; 经过35次循环之后,其可逆容量的保持率85.3%,具有良好的电化学性能.硅/石墨复合材料良好的电化学性能,使其在锂离子电池负极材料的生产及应用中具有重要研究价值.

       

      Abstract: One of the most important goals of the development of lithium ion battery is to get cathode materials with high capacity,and silicon materials with up to 4 200 mAh/g theoretical specific capacity have attracted researchers interest. However, the volume effects of silicon anode materials result in the rapid decline in the electrochemical cycling performance and limit its application in production. It researched Si and graphite doped through different proportions, with the method of high-energy ball milling and annealing. The results show that at the ratio of 2:1,the first specific discharge capacity can reach 2136.4 mAh/g. The capacity decays more slowly when silicon is doped with graphite, and 85.3% capacity is retained after 35 cycles. The silicon and graphite hybrid material presents a promising direction,and plays an important role in the production and application for anode materials for lithium ion batteries.

       

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