(1. 福州大学 材料科学与工程学院,福州 350108;
2. 厦门理工学院 材料科学与工程学院,厦门 361024)
摘 要: 采用热分解法在360 ℃制备了Ti/IrO2-SnO2-xCeO2(摩尔分数)电极,通过 X射线衍射(XRD)、交流阻抗(EIS)和循环稳定实验分析CeO2含量对 Ti/IrO2-SnO2-xCeO2涂层组织、电容性能、频率响应特性和循环稳定性的影响。结果表明:CeO2可抑制IrO2-SnO2晶化,随CeO2含量的增加,IrO2-SnO2的晶化程度逐渐下降。含20% CeO2电极比电容可达505.7 F/g,是同频率下Ti/IrO2-SnO2电极的3倍。CeO2含量不超过20%时,对电极的传荷电阻Rct及弛豫时间常数τ影响较小。经历6000次循环后,10% CeO2电极电容增加了34.39%,20% CeO2电极电容增加了3.45%,显示电极优良的抗电容衰减能力。
关键字: 超级电容器;电化学交流阻抗;频率特性;二氧化铱;二氧化铈
(1. College of Materials Science and Engineering, Fuzhou University,Fuzhou 350108, China;
2. College of Materials Science and Engineering, Xiamen University of Technology, Xiamen 361024, China)
Abstract:Ti/IrO2-SnO2-xCeO2 (mole fraction) electrodes with different mole fractions of CeO2 were obtained by thermal decomposition method at 360 ℃. The influences of the CeO2 content on microstructure and EIS properties of the prepared electrodes were investigated by XRD, EIS and stability test. The results show that the crystallization degree of the IrO2-SnO2 oxides decreases with increasing CeO2 content, which reveal that CeO2 can inhibit crystallization of IrO2-SnO2. The electrode with 20% CeO2 reaches maximum specific capacitance of 505.7 F/g, which is about three times than that of the IrO2-SnO2 binary oxides electrode. When the amount of CeO2 is less than 20%, the less effect on the transfer resistance (Rct) and relaxation time (τ) can be obtained. After 6000 times cycle, the specific capacitance of the electrode with 10%CeO2 increases by 34.39% and 20% CeO2 increases by 3.45%. The electrodes have good cyclic stability.
Key words: supercapacitor; electrochemical impedance spectroscopy; frequency-response characteristic; IrO2; CeO2