成分配比对RuO2-Ta2O5二元氧化物电容性能的影响

Effect of Composition on the Structure and Capacitive Performance

摘要:

采用热分解法制备了不同Ru/Ta配比的Ti/RuO2-Ta2O5二元混合氧化物电极材料。采用X射线衍射 (XRD)、循环伏安 (CV) 及恒流充放电测试分析了Ti/RuO2-Ta2O5电极的组织结构、伏安特性和恒流充放电性能。结果表明，随氧化钽含量的升高，RuO2-Ta2O5涂层的结晶程度逐渐下降，当Ta2O5含量≥70 mol%时，RuO2-Ta2O5混合氧化物完全以非晶态结构存在。Ti/RuO2-Ta2O5电极的比电容随Ta2O5含量的增加呈现先增后减的变化趋势。在Ta2O5含量为70 mol%时，电极具有较好的超电容性能，比电容达到621.2 F·g-1

Abstract:

A series of binary RuO2-Ta2O5 oxide composites with different Ru/Ta molar ratios were deposited on titanium substrate by a thermal decomposition method. The structure, voltametrical characteristics and capacitive properties as a function of the Ru/Ta molar ratios were investigated by X-ray diffraction (XRD), cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The results show that the degree of crystallization of the Ti/RuO2-Ta2O5 electrodes decreases with the increase of Ta2O5 content in the RuO2-Ta2O5 oxide coatings. A completely amorphous structure exists as the proportion of Ta2O5 is up to 70 mol% or higher. The electrochemical performance of the Ti/RuO2-Ta2O5 electrodes is closely related with the composition and structure. The specific capacitance increases firstly and then decreases with the ratio of Ta to Ru in oxide coatings, and a maximum specific capacitance of 621.2 F·g-1(RuO2) is obtained when the Ta2O5 content is 70 mol%.