高比能量Ti/(Ir_(0.3)Sn_(0.7-x)Ce_x)O_2电极材料的制备及其电化学性能

Preparation and electrochemical performance of Ti/(Ir_(0.3)Sn_(0.7-x)Ce_x)O_2 electrode materials with high specific energy

采用热分解法在360℃制备Ti/(Ir0.3Sn(0.7-x)Cex)O2三元氧化物电极材料(0<x<0.5)。采用X射线衍射(XRD)、交流阻抗和循环伏安法分析成分对Ti/(Ir0.3Sn(0.7-x)Cex)O2电极材料的晶体结构和电化学性能的影响。结果表明:适量的Ce可降低氧化物涂层中金红石相的晶化程度,优化氧化物涂层的结构,并提高Ti/(Ir0.3Sn(0.7-x)Cex)O2电极材料的电容性能。当x=0.2时,Ti/(Ir0.3Sn0.5Ce0.2)O2电极的比电容达到414 F/g,约为Ti/Ir O2-Sn O2二元氧化物电极的3倍;该电容材料表现出很高的比能量特性,在4.97 k W/kg的高功率密度放电时,对应的能量密度达到82.88 W·h/kg。当x≥0.3时,随着Ce含量增大,氧化物涂层的导电性能和频率响应特性会遭到恶化,对电极的电容性能不利。因此,Ce的含量控制在0.2(摩尔分数)以内为宜。

(Ir0.3Sn(0.7-x)Cex)O2 ternary oxide electrode materials(0<x<0.5) were obtained by thermal decomposition method on Ti substrate at a moderate temperature of 360℃. The influence of the compositions on microstructure and capacitive performance of the Ti/(Ir0.3Sn(0.7-x)Cex)O2 electrodes was investigated by XRD, electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV). The results show that a certain amount of Ce can reduce the degree of crystallization of rutile phase oxide in coating, optimize the microstructure of the oxide coating, and therefore improve the capacitive properties of the electrode material. When x is 0.2, the ternary oxides electrode reaches its maximum specific capacitance of 414 F/g, which is about three times of that of the Ti/Ir O2-Sn O2 electrode. The electrode shows a high specific energy density, when the power density is 4.97 k W/kg, the corresponding energy density reaches 82.88 W·h/kg. When x is more than 0.3, the electronic/protonic conductivity, frequency response characteristics as well as capacitive property of the Ti/(Ir0.3Sn(0.7-x)Cex)O2 electrodes are seriously deteriorated with increasing the Ce content. Therefore, the Ce content should be controlled in less than 0.2(mole fraction).