Chen Xu, Su Qiwei, Yu Jipan, Wei Mingrui, Guo Guanlun, Wang Yun
Hubei Key Laboratory of Advanced Technology for Automotive Components, Hubei Collaborative Innovation Center for Automotive Components Technology, Wuhan University of Technology Wuhan 430070 China
Hubei University of Arts and Science Xiangyang 441053 China
RSC Adv. 2021 Jul 20;11(41):25170-25178. doi: 10.1039/d1ra03362j. eCollection 2021 Jul 19.
In this paper, LaCoO powders were prepared by the urea combustion method and used as electrode materials for supercapacitors. The effect of the potential window and the current density on the performance degradation of LaCoO electrodes during the cycling test was analyzed. The degradation mechanism of LaCoO-based symmetric supercapacitors was discussed. The results of the cycling test show that: with the increase in potential window and current density, the performance degradation in the cycling test becomes more intense. The results of cyclic voltammetry tests, galvanostatic charge-discharge tests, X-ray photoelectron spectroscopy tests and KOH electrolyte concentration measurements before and after the cycling test show that the degradation of the supercapacitors is mainly caused by the occurrence and accumulation of irreversible redox reactions during the charge and discharge process, which reduces the ratio of Co/Co and the number of oxygen vacancies.
在本文中，采用尿素燃烧法制备了LaCoO粉末，并将其用作超级电容器的电极材料。分析了循环测试期间电位窗口和电流密度对LaCoO电极性能退化的影响。讨论了基于LaCoO的对称超级电容器的退化机制。循环测试结果表明：随着电位窗口和电流密度的增加，循环测试中的性能退化变得更加严重。循环伏安测试、恒电流充放电测试、X射线光电子能谱测试以及循环测试前后KOH电解液浓度测量结果表明，超级电容器的退化主要是由充放电过程中不可逆氧化还原反应的发生和积累引起的，这降低了Co/Co的比例和氧空位的数量。
