基于一阶RC模型的高频超级电容器电容成分分析

doi:10.19799/j.cnki.2095-4239.2025.0460

摘要/Abstract

摘要：

电化学阻抗谱(EIS)作为表征电极材料及电化学储能器件动力学行为的核心工具，可有效解析高频超级电容器中电荷转移与物质传输的耦合过程。为定量解析高频电容成分，本工作首先利用一阶RC模型提取电化学阻抗谱中能准确反映高频超级电容器性能的特征参数，随后将实测EIS数据作为特征输入参量，利用遗传算法对电容组分进行全局优化拟合，实现高频电容成分的定量解耦。为了验证该方法的普适性，选取石墨烯膜、碳纳米管膜、炭化三聚氰胺泡沫及商业化YP50F多孔炭为模型电极，开展高频EIS测试，并基于实测EIS数据开展电容成分分析。分析结果表明，高频电容呈现多弛豫特性——能量存储过程可解耦为C_Debye、C_HN和C_RBM弛豫过程，同时阐明弱短程离子相互作用是超级电容器优异高频响应性能的关键。本研究揭示了高频超级电容器电容成分的物理起源，所提出的分析方法为高频超级电容器材料筛选与界面工程提供了理论工具。

关键词: 超级电容器, 高频行为, 电化学阻抗谱, 遗传算法, 电容成分

Abstract:

Electrochemical impedance spectroscopy (EIS) is a fundamental technique for elucidating dynamic interactions within electrode materials and electrochemical energy storage systems, offering critical insights into the coupled mechanisms of charge transfer and ionic transport in high-frequency supercapacitors. To enable precise quantification of high-frequency capacitance components, this study utilizes a first-order RC equivalent circuit model to extract key electrochemical parameters from impedance spectra that directly correlate with device performance. These parameters are subsequently incorporated into a genetic algorithm-driven global optimization framework to achieve accurate decoupling of distinct capacitance contributions. To validate the robustness and universality of this approach, four representative electrode systems-graphene film, carbon nanotube film, carbonized melamine foam, and commercial YP50F porous carbon-were systematically investigated through high-frequency EIS characterization. Capacitance decomposition analysis based on the acquired impedance data revealed that high-frequency capacitance behavior involves multi-relaxation dynamics, which can be resolved into three distinct contributions: C_Debye, C_HN, and C_RBM relaxation processes. Importantly, the dominance of weak short-range ionic interactions was identified as the critical factor governing the superior high-frequency response characteristics of these supercapacitor systems. These findings clarify the fundamental physical origins underlying capacitance composition in high-frequency supercapacitors. The proposed integrated analysis methodology provides a robust theoretical framework for guiding material optimization and interface engineering strategies aimed at enhancing high-frequency supercapacitor performance.

Key words: supercapacitors, high-frequency behavior, electrochemical impedance spectroscopy, genetic algorithm, capacitor composition

中图分类号:

TM 53

范亚锋, 易宗琳, 谢莉婧, 李晓明, 苏方远. 基于一阶RC模型的高频超级电容器电容成分分析[J]. 储能科学与技术, 2025, 14(8): 2903-2912.

Yafeng FAN, Zonglin YI, Lijing XIE, Xiaoming LI, Fangyuan SU. Capacitor composition analysis of high-frequency supercapacitors based on first-order RC model[J]. Energy Storage Science and Technology, 2025, 14(8): 2903-2912.

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参数	石墨烯膜电极	碳纳米管膜电极	炭化泡沫电极
C_Debye/(μF/cm²)	0.91	1.54	98.17
C_HN/(μF/cm²)	29.90	84.58	284.61
C_RBM/(μF/cm²)	76.67	28.87	35.88
τ_Debye/s	1.74×10^-4	9.28×10^-6	8.84×10^-5
τ_HN/s	1.00×10^-2	1.00×10^-2	1.00×10^-2
τ_RBM/s	7.09×10^-2	9.56×10^-1	6.25×10^-1
α	0.88	0.35	0.25
β	0.40	3.00	2.81
γ	0.36	0.58	0.59