SiO_x/C复合材料的制备及电化学循环性能

Preparation and Electrochemical Cycle Performance of SiO_x/C Composite Anode Material

采用酸碱溶胶凝胶法、高温热解法以及高能球磨法,制备了SiOx/C复合材料,并探索了其最优化的制备条件.结果表明,在一定的盐酸与氨水浓度下,分别以摩尔比为4/1、4/1、30/1的水/正硅酸乙酯、葡萄糖/正硅酸乙酯、乙醇/正硅酸乙酯为原料,在氩气中850℃下焙烧30min后再球磨5h即可制备得到电化学循环性能良好的SiOx/C复合材料.XRD结果表明,该复合材料主要组成为低结晶度的SiO2和C.所制备的复合材料首周充、放电容量分别为653.5mAh/g和972.7mAh/g,循环20周后仍保持在671.4mAh/g,具有良好的循环稳定性.

SiOx/C anode material is prepared by an acid and alkali sol-gel method combined with a high temperature pyrolysis process and a high-energy ball-milling technique,and the optimized preparation conditions are investigated.The results show that the SiOx/C composite material with the promising electrochemical performance can be prepared with a mixture H2O/TEOS（molar ratio 4/1）and glucose/TEOS（molar ratio 4/1）and alcohol/TEOS（molar ratio 15/1）in certain concentrations of hydrochloric acid and ammonia as the starting materials after sintering at 850 ℃for 30 min in Ar atmosphere followed by ball milling for 5h.The XRD result indicates that the composites are composed of amorphous SiO2 and C.The initial charge/discharge capacity of the SiOx/C anode material is 653.5and 972.7 mAh/g,respectively.After 20 cycles,the reversible capacity still maintains above 671.4mAh/g,which shows a better cycle performance.