新型硅碳复合材料的制备及其电化学性能

Preparation of high capacity SiO/C/G material and its electrochemical properties

硅基负极材料由于具有高的比容量而获得较多关注。表面包覆碳层的氧化亚硅与人造石墨、胶黏剂在溶剂中高速分散后,用喷雾干燥的方式获得了复合材料颗粒。对比发现,喷雾复合制备的材料性能优于物理混合方式,并通过阻抗分析初步探明了喷雾复合方式具有优势的原因。在合成过程中加入质量分数1%的纳米碳纤维进一步优化了硅碳复合材料性能,用该材料制成试样电池,50周循环后容量保持率96%,具有较好的应用潜力。

Silicon-based anode materials have been widely concerned for its promising high specific capacity. SiO powders were firstly coated with a layer of conformal carbon, which significantly improved the conductive characteristic of the particles. The as-obtained SiO@C, artificial graphite and binders were dispersed in solvents at a high speed and composite particles were obtained by spray drying. It shows that the electrochemical performance of the materials obtained from spray drying is much better than that from physical mixture. To optimize the material, carbon nanofibers are incorporated during the dispersion process;over 96% capacity retention and about 25% capacity increase than graphite are obtained over 50 cycles, which makes it with a potential commercial value.