The redox-active electrolyte supercapacitor (RAES) is a relatively new type of energy storage device. Simple addition of selected redox species in the electrolyte can greatly enhance the energy density of supercapacitors relative to traditional electric double layer capacitors (EDLCs) owing to redox reactions. Studies on the kinetics at the interface of the electrode and redox mediator are important when developing RAESs. In this work, we employ highly accurate scanning electrochemical microscopy (SECM) to extract the kinetic constants at carbon/hydroquinone interfaces. The charge transfer rate constants are 1.2 × 10^–2 and 1.3 × 10^–2 cm s^–1 for the carbon nanotube/hydroquinone and reduced graphene oxide/hydroquinone interfaces, respectively. These values are higher than those obtained by the conventional cyclic voltammetry method, approximately by an order of magnitude. The evaluation of heterogeneous rate constants with SECM would be the cornerstone for understanding and developing high performance RAESs.

中文翻译：

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氧化还原-活性-电解质超级电容器在碳/氢醌界面的电荷转移动力学研究

氧化还原活性电解质超级电容器（RAES）是一种相对新型的能量存储设备。由于氧化还原反应，相对于传统的双电层电容器（EDLC），在电解质中简单添加选定的氧化还原物质可大大提高超级电容器的能量密度。在开发RAES时，对电极和氧化还原介体界面的动力学进行研究非常重要。在这项工作中，我们采用高精度扫描电化学显微镜（SECM）提取碳/氢醌界面的动力学常数。电荷传输速率常数为1.2×10 ^–2和1.3×10 ^–2 cm s ^–1分别用于碳纳米管/对苯二酚和还原的氧化石墨烯/对苯二酚界面。这些值比通过常规循环伏安法获得的值高大约一个数量级。用SECM评估异构速率常数将成为理解和开发高性能RAES的基石。