Peyrow Hedayati Davood, Singh Gita, Kucher Michael, Keene Tony D, Böhm Robert
Faculty of Engineering, Leipzig University of Applied Sciences, 04277 Leipzig, Germany.
School of Chemistry, University College Dublin, Belfield, 4 Dublin, Ireland.
Materials (Basel). 2023 Jan 31;16(3):1232. doi: 10.3390/ma16031232.
Solid-state supercapacitors (SSCs) consist of porous carbon electrodes and gel-polymer electrolytes and are used in novel energy storage applications. The current study aims to simulate the impedance of SSCs using a clearly defined equivalent circuit (EC) model with the ultimate goal of improving their performance. To this end, a conventional mathematical and a physicochemical model were adapted. The impedance was measured by electrochemical impedance spectroscopy (EIS). An EC consisting of electrical elements was introduced for each modeling approach. The mathematical model was purely based on a best-fit method and utilized an EC with intuitive elements. In contrast, the physicochemical model was motivated by advanced theories and allowed meaningful associations with properties at the electrode, the electrolyte, and their interface. The physicochemical model showed a higher approximation ability (relative error of 3.7%) due to the interface impedance integration in a more complex circuit design. However, this model required more modeling and optimization effort. Moreover, the fitted parameters differed from the analytically calculated ones due to uncertainties in the SSC's microscale configuration, which need further investigations. Nevertheless, the results show that the proposed physicochemical model is promising in simulating EIS data of SSCs with the additional advantage of utilizing well-reasoned property-based EC elements.
固态超级电容器（SSCs）由多孔碳电极和凝胶聚合物电解质组成，用于新型储能应用。当前的研究旨在使用明确定义的等效电路（EC）模型模拟SSCs的阻抗，最终目标是提高其性能。为此，采用了传统的数学模型和物理化学模型。通过电化学阻抗谱（EIS）测量阻抗。针对每种建模方法引入了一个由电气元件组成的等效电路。数学模型纯粹基于最佳拟合方法，并使用了具有直观元件的等效电路。相比之下，物理化学模型则基于先进理论，能够与电极、电解质及其界面处的性质建立有意义的关联。由于在更复杂的电路设计中集成了界面阻抗，物理化学模型显示出更高的近似能力（相对误差为3.7%）。然而，该模型需要更多的建模和优化工作。此外，由于SSCs微观结构的不确定性，拟合参数与分析计算的参数不同，这需要进一步研究。尽管如此，结果表明，所提出的物理化学模型在模拟SSCs的EIS数据方面很有前景，其额外优势在于使用了基于合理性质的等效电路元件。
