Wanchan Waritnan, Yeetsorn Rungsima, Kuboon Sanchai, Yogesh Gaurav Kumar
Materials and Production Engineering, The Sirindhorn International Thai-German Graduate School of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand.
Materials and Production Engineering, The Sirindhorn International Thai-German Graduate School of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand.
Bioresour Technol. 2025 Sep 9;439:133303. doi: 10.1016/j.biortech.2025.133303.
Understanding the influence of electrolyte composition on charge storage behavior is essential for optimizing supercapacitor performance. This study explores how electrolyte type and concentration affect the electrochemical properties and storage mechanisms of porous activated carbon derived from sugarcane leaves (SLAC). With a high surface area (2006.91 m g) and hierarchical porosity, SLAC was evaluated in three aqueous electrolytes, HSO, NaSO, and KOH, at concentrations of 1, 3, and 6 M. Results revealed that SLAC predominantly exhibited electrical double-layer capacitance in acidic and neutral media. In contrast, under alkaline conditions, especially with 6 M KOH, a significant pseudocapacitive contribution emerged, attributed to enhanced OH ion adsorption and surface redox reactions. Notably, the 6 M KOH system achieved a maximum specific capacitance of 254 F g at 0.5 A g and excellent cycling stability with 94.48 % retention over 5,000 cycles. Kinetic analysis showed a transition from surface-controlled to diffusion-controlled charge storage with increasing KOH concentration. This work addresses a key knowledge gap by systematically correlating electrolyte characteristics with charge storage mechanisms in biomass-derived carbons. The study demonstrates that optimizing electrolyte identity and concentration, in conjunction with a well-designed hierarchical pore structure, can significantly enhance ion transport and capacitance. The findings provide a novel strategy for tuning electrochemical behavior in sustainable carbon-based supercapacitors, offering valuable insights for the development of high-performance energy storage devices.
了解电解质组成对电荷存储行为的影响对于优化超级电容器性能至关重要。本研究探讨了电解质类型和浓度如何影响源自甘蔗叶的多孔活性炭（SLAC）的电化学性质和存储机制。SLAC具有高比表面积（2006.91 m²/g）和分级孔隙率，在1 M、3 M和6 M浓度的三种水性电解质H₂SO₄、Na₂SO₄和KOH中进行了评估。结果表明，SLAC在酸性和中性介质中主要表现出双电层电容。相比之下，在碱性条件下，特别是使用6 M KOH时，出现了显著的赝电容贡献，这归因于OH⁻离子吸附增强和表面氧化还原反应。值得注意的是，6 M KOH体系在0.5 A/g时实现了254 F/g的最大比电容，并具有出色的循环稳定性，在5000次循环中保留率为94.48%。动力学分析表明，随着KOH浓度的增加，电荷存储从表面控制转变为扩散控制。这项工作通过系统地将电解质特性与生物质衍生碳中的电荷存储机制相关联，填补了关键的知识空白。该研究表明，优化电解质种类和浓度，结合精心设计的分级孔隙结构，可以显著增强离子传输和电容。这些发现为调节可持续碳基超级电容器中的电化学行为提供了一种新策略，为高性能储能装置的开发提供了有价值的见解。
