Monitoring and modeling the variation of electrochemical current induced by dynamic strain at gold surfaces

Abstract

This study investigates the electrochemical charging and discharging processes at a strained gold surface using dynamic mechanical deformation. The electrocapillary coupling coefficient in our study, Λ, measures the response of the capacitive current to the mechanical elastic strain with a focus on the potential range of the double layer capacitive process of interest. The variation in the magnitude of Λ during the potential scan shows that the impact of surface strain on the capacitive current is strongly dependent on the electrode states. The positive sign of Λ implies that tensile strain can enhance the charging current on the electrode surface, whereas tensile strain has the opposite effect on the discharging current with the potential changing in the negative direction. Moreover, a simple equivalent circuit was used to further characterize the coupling between the capacitive process and mechanical strain at the gold surface for exploring the application in the field of electrochemical energy storage.