Kim Jong Gyeong, Cho Young Hun, Yoo Seung Joon, Pak Chanho
Department of Chemistry and Graduate School of Energy Convergence, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea.
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, 61005, Republic of Korea.
Small. 2025 Jun;21(24):e2500946. doi: 10.1002/smll.202500946. Epub 2025 Apr 28.
In energy storage systems utilizing redox reactions in the electrolyte (redox-enhanced electrochemical capacitors; redox ECs), electrode materials play a critical role: pore size distribution, free volume, and internal surface area directly impact the adsorption and diffusion of redox-active species at the electrode/electrolyte interface, thereby influencing overall energy storage capacity and efficiency. Importantly, achieving optimal full-cell performance requires tailored hierarchical pore architectures capable of accommodating structurally distinct redox-active species (catholytes and anolytes). Here, a streamlined precursor engineering strategy is presented to fabricate hierarchical, multi-scale porous carbon structures, providing a simplified alternative to conventional acid etching or resource-intensive pre-treatments. The porous carbon is engineered through thermal oxidation of precursor composites at moderate temperatures, combined with precise modulation of KCO during activation. This approach yields a carbon material with a well-balanced pore structure, featuring a micropore volume of 0.74 cm g and a mesopore volume of 1.64 cm g, and a specific surface area of 3,309 m g. When applied in a pentyl viologen/bromide dual redox EC, this system achieves a record-high energy density of 125 Wh kg. These findings highlight the significant relationship between pore structure and redox EC performance, offering valuable insights for advanced carbon materials in energy storage systems.
在利用电解质中的氧化还原反应的储能系统（氧化还原增强型电化学电容器；氧化还原ECs）中，电极材料起着关键作用：孔径分布、自由体积和内表面积直接影响氧化还原活性物质在电极/电解质界面处的吸附和扩散，从而影响整体储能容量和效率。重要的是，要实现最佳的全电池性能，需要有能够容纳结构不同的氧化还原活性物质（阴极电解液和阳极电解液）的定制分级孔结构。在此，提出了一种简化的前驱体工程策略来制备分级多尺度多孔碳结构，为传统的酸蚀刻或资源密集型预处理提供了一种简化的替代方法。通过在中等温度下对前驱体复合材料进行热氧化，并结合活化过程中KCO的精确调节来设计多孔碳。这种方法得到一种具有平衡孔结构的碳材料，其微孔体积为0.74 cm³/g，中孔体积为1.64 cm³/g，比表面积为3309 m²/g。当应用于戊基紫精/溴化物双氧化还原EC中时，该系统实现了创纪录的125 Wh/kg的高能量密度。这些发现突出了孔结构与氧化还原EC性能之间的重要关系，为储能系统中的先进碳材料提供了有价值的见解。
