采用溶胶凝胶法、高温固相合成法和高能球磨法制备了Si/Li2TiO3复合材料,并研究了最优化制备条件.结果表明,以摩尔比为2/1的硅/钛酸四丁酯和摩尔比为9/1的水/葡萄糖的混合物为起始原料,在700℃下焙烧24h后再球磨6h即可制备电化学性能优良的Si/Li2TiO3复合材料.XRD结果显示,该复合材料中除含有少量C外,主要为Si和Li2TiO3相.恒流电化学充放电结果表明,该复合材料首周吸锂容量和放锂容量分别为1 497.9和1 199.3mAh/g,首周效率80.1%,循环50周后容量仍可以保持在471.0mAh/g.
Si/Li2TiO3 composite anode material is prepared by a sol-gel method combined with a high-temperature solid-phase synthesis process followed by a ball milling process,and the optimized preparation conditions are investigated.The results show that the Si/Li2TiO3 composite material with the promising electrochemical performance can be prepared with a mixture of Si/Ti(OC4H9)4(molar ratio 2/1) and H2O/C6H12O6(molar ratio 11/1) as the starting materials after sintering at 700 ℃ for 24 h followed by ball milling for 6 h.The XRD results show that the composite material mainly contains Si and Li2TiO3 phases besides a C phase.Electrochemical galvanostatic charge and discharge results indicate that the Si/Li2TiO3 anode delivers an initial lithiation and delithiation capacity of 1 497.9 mAh/g and 1 199.3 mAh/g,respectively,with a coulombic efficiency of 80.1%.After 50 cycles,the retained capacity reaches 471.0 mAh/g.