Side reactions of water decomposition and capacitive reactions occur concomitantly in aqueous supercapacitors. To improve the energy density, integrated design modifications to address the impact of these two aspects on the reaction kinetics are theoretically effective. Herein, a two-step modification strategy for introducing binary functional species is designed to regulate the chemical environment and electronic structure of the metal active sites and further optimize the electrochemical kinetics comprehensively. For promoting the capacitive reactions, Ag nanoparticles were loaded to decrease the corresponding energy barriers. For suppressing the oxygen evolution side reaction, preintercalation of K⁺ ions was realized to increase the corresponding energy barriers. The assembled supercapacitor device shows an ultrahigh energy density of 143.2 Wh kg^–1. Uniquely, in situ techniques, DFT calculations, and overpotential tests are combined to verify the suppression mechanism. This work provides valuable guidance for coordinating designs and studies on the electrochemical kinetics of transition-metal-based electrode materials.

中文翻译：

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二元官能团的可控整合为基于 CoNiSe2 的高性能超级电容器提供了方向优化的动力学


水分解和电容反应的副反应在水性超级电容器中同时发生。为了提高能量密度，理论上有效的集成设计修改来解决这两个方面对反应动力学的影响。在此，设计了一种引入二元官能团物种的两步修饰策略，以调节金属活性位点的化学环境和电子结构，并进一步全面优化电化学动力学。为了促进电容反应，加载了 Ag 纳米颗粒以减少相应的能量势垒。为了抑制析氧副反应，实现了 K⁺ 离子的预嵌入以增加相应的能垒。组装的超级电容器器件显示出 143.2 Wh kg^–1 的超高能量密度。独特的是，将原位技术、DFT 计算和过电位测试相结合，以验证抑制机制。这项工作为协调过渡金属基电极材料的电化学动力学设计和研究提供了有价值的指导。