Ti/Mn(0.8-x)SnxIr0.2O2电极的电容性能研究

Analysis of Capacitive Properties of Ti/Mn(0.8-x)SnxIr0.2O2 Electrodes

摘要:

采用热分解法制备了Ti/Mn_(0.8-x)Sn_xIr_0.2O₂三元氧化物电极材料。通过扫描电子显微镜,X 射线衍射、循环伏安和交流阻抗谱等分析了Ti/Mn_(0.8-x)Sn_xIr_0.2O₂电极材料的组织结构和电容性能。结果表明：SnO₂对涂层的组织结构有较大影响,随SnO₂含量增加,氧化物涂层中正方结构Mn₃O₄相逐渐减少,正方结构SnO₂相逐渐增加。与锰铱二元氧化物相比,SnO₂的加入可明显改善电极材料在0~0.5V区间的电流响应,并促进氧化锰活性的发挥,但在一定程度上也抑制了氧化铱的活性。SnO₂的加入也改变了电极材料的电荷转移电阻、弛豫时间常数、以及不同频率下的电容响应速度。相比其它电极材料,Ti/Ir_0.2Mn_0.6Sn_0.2O₂电极材料在低频范围(≤ 1Hz)有更好的电容响应和更高的活性,因而获得最高的比电容值。

Abstract:

An experimental set-up was designed for measuring the self-field losses of Bi2223/Ag HTS tapes using a transport current method. Ti/Mn_(0.8-x)Sn_xIr_0.2O₂ ternary oxide electrode materials were obtained by Pechini sol-gel method. The organizational structure and electrochemical performance of Ti/Mn_(0.8-x)Sn_xIr_0.2O₂ electrodeswas investigated by Scanning electron microscope (SEM), X ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that: SnO₂ has a great influence on the organization structure of coating. With the content of SnO₂ increasing, affirmative structure of Mn₃O₄ phase in Ti/Mn _(0.8-x) Sn_xIr_0.2O₂ electrodes oxide coating is gradually reduced, but affirmative structure of SnO₂ phase increased. Compared with the Mn-Ir-based binary oxides, the addition of SnO₂ can significantly improve the current response of electrodes in the range of 0~0.5V and enhance activity of manganese oxide, but suppress activity of iridium oxide. Impedance analysis indicated that the charge transfer resistance,the relaxation time constant and the capacity of different frequency response of electrode materials were changed after addition of SnO₂. In contrast, the Ti/Ir_0.2Mn_0.6Sn_0.2O₂ electrode with better capacitance response and higher activity in the low frequency range (≤ 1Hz), demonstrates the highest specific capacitance.