基于表面改性纳米硅复合负极材料的制备及其性能

Preparation and Performance of Silicon Nanoparticles Composite Anode Material Based on Surface Modification

基于简单易操作的湿法包覆制备了以纳米硅粉体和石墨(G)为主要原料,添加表面活性剂脂肪醇聚氧乙烯醚和石墨烯(GR)的Si/C@GR/G复合材料。研究了不同组分配比对复合材料的成分、形貌及电化学性能的影响。结果表明:制得的复合材料具有良好的循环稳定性,体积膨胀得到缓解。当复合材料中硅质量分数为10%,首次放电比容量约为730 mA·h/g,在电流密度为100 mA/g经100次循环后,其放电比容量稳定维持在500 mA·h/g左右,也展现了良好的倍率性能,首次Coulombic效率达到87.27%,相比纯硅不足70%的效率有了大幅度提高。

Si/C@graphene(GR)/graphite(G)composite anode materials were prepared by a simple and easy-to-operate wet coating method with silicon nanoparticles and graphite as main raw materials,fatty alcohol polyoxyethylene ether as a surfactant and graphene.The effect of allocation ratio on the composition,morphology and electrochemical performance of the composite materials was investigated.The results show that the prepared composite materials exhibit a superior cycling stability,and the volume expansion alleviates.When the silicon nanoparticles content is 10%,the initial discharge capacity is approximately 730 m A·h/g.After 100 cycles at a current density of 100 m A/g,the discharge capacity can stably maintain at 500 m A·h/g.The initial coulomb efficiency reaches 87.27%,revealing a great improvement in comparison with the efficiency of pure silicon material(i.e.,less than 70%).