Correlated surface- charging behaviors of two electrodes in an electrochemical cell

It is revealed herein that surface-charging behaviors of the two electrodes constituting an electrochemical cell cannot be described independently by their respective electric double -layer (EDL) properties. Instead, they are correlated in such a way that the surface-charging behavior of each electrode is determined by the EDL and the reaction kinetics at both electrodes. Two fundamental equations describing the correlated surface-charging behaviors are derived, and approximate analytical solutions are obtained at low and high current densities, respectively, to facilitate transparent understanding. Important implications of the presented conceptual analysis for theoretical and computational electrochemistry are discussed. A strategy of modulating the activity of one electrode by tuning EDL parameters of the other in a two-electrode electrochemical cell is demonstrated.

Automated summary

This paper reveals that the surface-charging behaviors of the electrodes in an electrochemical cell are not independently described by their electric double-layer properties. Instead, they are correlated and determined by the electric double-layer and reaction kinetics of both electrodes. Two fundamental equations are derived to describe the correlated surface-charging behaviors, and approximate analytical solutions are provided for low and high current densities for better understanding. The implications of this conceptual analysis for theoretical and computational electrochemistry are discussed, and a strategy to modulate the activity of one electrode by tuning the electric double-layer parameters of the other electrode in a two-electrode electrochemical cell is demonstrated.