Unified kinetic description of bulk and interfacial electrochemical processes from the perspective of ion-vacancy coupled transfer

The conventional electrochemical kinetic theories describe multiphase mass transport and interfacial charge transfer individually by different equations, which are weakly coupled with each other at boundaries. This minireview aims at generalizing the kinetic description of various processes involved in electrochemical energy systems by treating them microscopically in terms of random ion hopping with a dynamic lattice-gas model. The unified kinetic equation thus obtained can be reduced to the continuum equation for ion transport in the bulk and the Butler-Volmer equation at the solid-electrolyte interfaces. Particularly, the standard reaction rate constant in the unified kinetic equation is extracted as a generalized kinetic descriptor of these processes. The application of the generalized theory is also discussed.