文献类型：期刊文献

英文题名：Microscopic Model for Cyclic Voltammetry of Porous Electrodes

作者：Lin, Yiting[1];Lian, Cheng[1];Berrueta, Mikel Unibaso[2];Liu, Honglai[1];van Roij, Rene[2]

机构：[1]East China Univ Sci & Technol, Shanghai Engn Res Ctr Hierarch Nanomat, Sch Chem & Mol Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Utrecht, Inst Theoret Phys, Ctr Extreme Matter & Emergent Phenomena, Princetonpl 5, NL-3584 CC Utrecht, Netherlands

年份：2022

卷号：128

期号：20

外文期刊名：PHYSICAL REVIEW LETTERS

收录：;EI(收录号：20222412212455);WOS:【SCI-EXPANDED(收录号:WOS:000804734100002)】；

基金：This work is part of the D-ITP consortium, a program of the Netherlands Organisation for Scientific Research (NWO) that is funded by the Dutch Ministry of Education, Culture and Science (OCW). C. L. and R. v. R. acknowledge the EU-FET Project No. NANOPHLOW (REP-766972-1), and C. L. and H. L. acknowledge NSFC (91834301, 22078088). We thank Dr. Mathijs Janssen for enlightening discussions, Dr. Yongfeng Bu for access to the experimental data of Ref. [40], and the Referees for their helpful comments and suggestions.

语种：英文

外文关键词：Capacitance - Electrodes - Equivalent circuits - Pore size - Supercapacitor

摘要：Cyclic voltammetry (CV) is a widespread experimental technique for characterizing electrochemical devices such as supercapacitors. Despite its wide use, a quantitative relation between CV and microscopic properties of supercapacitors is still lacking. In this Letter, we use both the microscopic "stack-electrode" model and its equivalent circuit for predicting the cyclic voltammetry of electric double-layer formation in porous electrodes. We find that the dimensionless combination omega tau(n), with omega the scan frequency of the time-dependent potential and tau(n) the relaxation timescale of the stack-electrode model, governs the CV curves and capacitance: the capacitance is scan-rate independent for omega tau(n) << 1 and scan-rate dependent for omega tau(n) >> 1. With a single fit parameter and all other model parameters dictated by experiments, our model reproduces experimental CV curves over a wide range of omega. Meanwhile, the influence of the pore size distribution on the charging dynamics is investigated to explain the experimental data.