滴加速率对TiO_2/RGO复合材料结构和储钠性能的影响

Effect of Feeding Rate on the Structure and Storage Properties of TiO_2/RGO Composites

以钛酸丁酯为前驱物,无水乙醇为溶剂,采用溶胶-凝胶法和热处理法制备了钠离子电池TiO_2/还原氧化石墨烯复合负极材料(TiO_2/RGO),研究了溶胶-凝胶法过程中反应物钛酸丁酯滴加速率对TiO_2/RGO复合材料形貌结构及储钠性能的影响。结果表明,TiO_2/RGO复合材料由锐钛矿相TiO_2和还原氧化石墨烯组成,TiO_2富集在RGO片层边缘。电化学测试结果表明,随着滴加速率的增大,首次放电比容量和库伦效率呈现先增大后减小的趋势;当滴加速率为1.0mL/min时,TiO_2/RGO复合材料具有良好的储钠性能,在1C(1C=20mA·g^(-1))倍率下首次放电比容量和库伦效率分别为140.14mAh·g^(-1)和27.92%,具有良好的循环和倍率性能。

With ethanol as solvent and Ti（OBu）4as precursor,the process for preparing TiO2/reduced graphene oxide composite（TiO2/RGO）by sol-gel method and heat treatment was studied.The effect of Ti（OBu）4feeding rate on the morphology,structure and storage properties of TiO2/RGO in the sol-gel process was studied.Results showed that the TiO2/RGO composite was composed of anatase TiO2 and reduced graphene oxide,and TiO2 concentrated at the edge of the RGO layer.Electrochemical test results showed that the initial discharge capacity and coulombic efficiency increased first and then decreased with the increase of cycle times.When the feeding rate is 1.0mL/min,the TiO2/RGO composites possessed good performance of sodium storage,as the initial discharge capacity and initial coulombic efficiency were 140.14mAh·g^-1 and 27.92% at a current rate of 1C（1C=20 mA·g^-1）,as well as good cycle and rate performance.