TiO2纳米管阵列制备及其电化学嵌锂性能研究

摘要

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-l, respectively.%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73.3 μAh·cm-2,100次循环后容量仍维持在65.5 μAh·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7.7x109cm2·s-1,嵌锂表观活化能为58.4KJ·tool-1.