TiO_2纳米管阵列制备及其电化学嵌锂性能研究

Preparation and Electrochemical Lithium Insertion of TiO_2 Nanotube Arrays

本文研究了TiO2纳米管阵列制备及其嵌锂电化学性能。采用阳极氧化法制备了TiO2纳米管阵列。利用XRD、SEM、恒电流充放电、CV、EIS等手段,对所制备TiO2纳米管阵列的结构、形貌进行了分析表征及电化学性能测试。实验结果表明,制备出的TiO2纳米管阵列薄膜具有很好的循环性能,首次嵌锂容量达73.3μAh.cm-2,100次循环后容量仍维持在65.5μAh.cm-2,容量保持率为89.4%,库仑效率达95%以上;锂离子在TiO2纳米管阵列中的扩散系数为7.7×10-9 cm2.s-1,嵌锂表观活化能为58.4kJ.mol-1。

This paper reports on the preparation of TiO2 nanotube arrays and their electrochemical lithium insertion properties.Anodization method is used to prepare self-organized TiO2 nanotube arrays.The crystal structure,morphologies,and electrochemical properties of the as-prepared TiO2 nanotube arrays are characterized by X-ray diffraction（XRD）,sanning electron microscopy（SEM）,galvanostatic change/discharge,cyclic voltammetric（CV）,and electrochemical impedance spectra（EIS）.The results show that the TiO2 nanotube arrays exhibit good cycle performance,delivering an initial discharge capacity of 73.3 μAh·cm-2 and 65.5 μAh·cm-2 after 100 cycles（with the retention of 89.4%）.The diffusion coefficient and apparent activation energies of lithium insertion in the TiO2 nanotube arrays are calculated to be 7.7×10-9 cm2·s-1 and 58.4 kJ·mol-1,respectively.