Interpreting concentration and activation overpotentials in electrochemical systems: A critical discussion

Abstract

In electrochemical systems, it is often desirable to separately quantify the effect of mass transferand reaction kinetics on the cell potential. Respective concentration (mass transfer) and activation (reaction kinetics) overpotentials are frequently defined in different ways. In this work,we discuss the implications of these alternative definitions. In particular, we emphasize that thedifferent definitions for activation and concentration overpotential: (i) cannot be chosen independently to additively partition the cell potential, (ii) can lead to significantly different values,and (iii) result in different meanings of the respective overpotentials. If not applied carefully,they can thus easily result in misinterpretations.

Authors 3

1. J. Raphael Seidenberg Aachen Process Systems Engineering (AVT.SVT)

   RWTH Aachen University · KU Leuven

   Affiliation as printed

   Department of Chemical Engineering , KU Leuven , 3001 Leuven , Belgium

   Process Systems Engineering (AVT.SVT) , RWTH Aachen University , 52074 Aachen , Germany

2. Alexander Mitsos
3. Dominik Bongartz

   KU Leuven

   Affiliation as printed

   Department of Chemical Engineering , KU Leuven , 3001 Leuven , Belgium