Mo Tangming, Zhou Jianguo, He Haoyu, Zhu Bingzheng
School of Mechanical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, Guangxi University, Nanning, Guangxi 530004, China.
ACS Appl Mater Interfaces. 2023 Nov 8;15(44):51274-51280. doi: 10.1021/acsami.3c12913. Epub 2023 Oct 25.
Nanopore electrodes have the potential to enhance the energy density of supercapacitors but tend to reduce charging dynamics, consequently impacting power density. A comprehensive understanding of their charging mechanisms can provide insights into how to boost charging dynamics. In this work, we conducted constant-potential-based molecular dynamics simulations to explore the charging mechanism of nanopore supercapacitors with organic electrolytes. Contrary to the traditional understanding associating larger pore sizes with faster charging, our results found a complex oscillatory behavior of the charging rate, correlating with nanopore size in organic electrolytes. An anomalously increased charging dynamics was found in the 0.9 nm pore. This anomalous enhancement can be attributed to the improved in-pore ion diffusion and reduced desolvation energy, owing to the orientation transition of the solvate molecules. These results pave a new way for innovative designs of nanoporous electrode supercapacitors that can enlarge both power and energy densities.
纳米孔电极有潜力提高超级电容器的能量密度，但往往会降低充电动力学，从而影响功率密度。全面了解其充电机制有助于深入了解如何提高充电动力学。在这项工作中，我们进行了基于恒电位的分子动力学模拟，以探索含有有机电解质的纳米孔超级电容器的充电机制。与传统观念认为较大孔径充电更快相反，我们的结果发现充电速率呈现复杂的振荡行为，这与有机电解质中纳米孔的大小相关。在0.9纳米孔径的纳米孔中发现充电动力学异常增加。这种异常增强可归因于溶剂化分子的取向转变导致孔内离子扩散改善和去溶剂化能降低。这些结果为纳米多孔电极超级电容器的创新设计开辟了一条新途径，这种设计可以同时提高功率和能量密度。
