Capacitor composition analysis of high-frequency supercapacitors based on first-order RC model

doi:10.19799/j.cnki.2095-4239.2025.0460

Abstract

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

CLC Number:

TM 53

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.

Figures/Tables 8

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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