Theoretical background of electron tunneling in electrochemical double layer

The electron tunneling or overflow in the electrochemical double layer has been mentioned in many previous reports, but its detailed influence mechanism is often neglected. In this work, we combined quantum chemistry and electrochemical double layer theory mathematically to investigate the reason for the nonlinear distribution of potential. By analyzing the electron transfer theory, we determined the condition and criterion for electron tunneling. We derived a formula for the relation between diffusion layer potential and electrode potential and compared it with the traditional model. The resulting curve exhibits a widened, sloped platform near the zero potential point. In addition, we analyzed the effects of the electrochemical double layer on input system signals using signal simulation. These results provide a foundation for further research in this area.