Boundary conditions for electrochemical interfaces
- Landstorfer, Manuel
2010 Mathematics Subject Classification
- 78A57 35Q35 34B15
2010 Physics and Astronomy Classification Scheme
- 82.45.Fk, 82.45.Gj, 68.43.Mn, 82.45.-h
- Boundary conditions, double layer charging, charge transfer, current voltage relation, mixture theory, electrode/electrolyte interface
Consistent boundary conditions for electrochemical interfaces, which cover double layer charging, pseudo-capacitive effects and transfer reactions, are of high demand in electrochemistry and adjacent disciplines. Mathematical modeling and optimization of electrochemical systems is a strongly emerging approach to reduce cost and increase efficiency of super-capacitors, batteries, fuel cells, and electrocatalysis. However, many mathematical models which are used to describe such systems lack a real predictive value. Origin of this shortcoming is the usage of oversimplified boundary conditions. In this work we derive the boundary conditions for some general electrode-electrolyte interface based on non-equilibrium thermodynamics for volumes and surfaces. The resulting equations are widely applicable and cover also tangential transport. The general framework is then applied to a specific material model which allows the deduction of a current-voltage relation and thus a comparison to experimental data. Some simplified 1D examples show the range of applicability of the new approach.
- J. Electrochem. Soc., 164 (2017) pp. 3671--3685.