Nonequilibrium Electrical Double Layer Effects on Unilateral Peak Suppression in Cyclic Voltammetry

ACS electrochemistry., vol. 2, pp. 1148–1160

Abstract

High Resolution Image Download MS PowerPoint Slide While equilibrium electrical double layer (EDL) effects on steady-state voltammetry have been studied, nonequilibrium transient EDL effects on cyclic voltammetry (CV) remain less understood. Herein, we report a combined theoretical and experimental study of nonequilibrium EDL effects on CV, focusing on their unequal influence over the cathodic and anodic peaks. The experiments are analyzed with the aid of a theoretical model coupling the Poisson–Nernst–Planck (PNP) theory and various electrode kinetic theories that can describe interfacial electron transfer reaction, EDL formation, and macroscopic mass transport in a unified framework. Consistent with experiments, the model predicts suppressed cathodic peaks for the CV of the [Fe(CN) 6 ] 3–/4– redox reaction and correlates them with the spatiotemporal distributions of electrical potential and reactant concentration in the EDL. The model is then utilized as an efficient computational tool for exploration in the vast parametric space, identifying parametric regions where pronounced nonequilibrium EDL effects could be observed in CV. A regime diagram of nonequilibrium EDL effects on CV is calculated and validated partly with experiments. In general, the unilateral suppression of CV peaks is more pronounced when the reactive ion is repelled from the like-charged electrode surface at a higher scanning rate.

Authors 3

1. Yupeng Qin

   Chinese Academy of Sciences · University of Chinese Academy of Sciences · Dalian Institute of Chemical Physics

   Affiliation as printed

   Dalian Institute of Chemical Physics, Chinese Academy of Sciences

   Laboratory of Advanced Spectro-electrochemistry and Li-Ion Batteries

   University of the Chinese Academy of Sciences

2. Zhangquan Peng corresponding

   Chinese Academy of Sciences · Dalian Institute of Chemical Physics

   Affiliation as printed

   Dalian Institute of Chemical Physics, Chinese Academy of Sciences

   Laboratory of Advanced Spectro-electrochemistry and Li-Ion Batteries

3. Jun Zh. Huang corresponding Aachen

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

   Faculty of Georesources and Materials Engineering

   Forschungszentrum Jülich GmbH

   Institute of Energy Technologies, IET-3: Theory and Computation of Energy Materials

   RWTH Aachen University