Quantitative Phase Field Model for Electrochemical Systems

Abstract

Modeling microstructure evolution in electrochemical systems is vital for understanding the mechanism of various electrochemical processes. In this work, we propose a general phase field framework that is fully variational and thus guarantees that the energy decreases upon evolution in an isothermal system. The bulk and interface free energies are decoupled using a grand potential formulation to enhance numerical efficiency. The variational definition of the overpotential is used, and the reaction kinetics is incorporated into the evolution equation for the phase field to correctly capture capillary effects and eliminate additional model parameter calibrations. A higher-order kinetic correction is derived to accurately reproduce general reaction models such as the Butler-Volmer, Marcus, and Marcus-Hush-Chidsey models. Electrostatic potentials in the electrode and the electrolyte are considered separately as independent variables, providing additional freedom to capture the interfacial potential jump. To handle realistic materials and processing parameters for practical applications, a driving force extension method is used to enhance the grid size by three orders of magnitude. Finally, we comprehensively verify our phase field model using classical electrochemical theory.

References in corpus (5)

• Theory of Chemical Kinetics and Charge Transfer based on Nonequilibrium Thermodynamics
• Unified derivation of phase-field models for alloy solidification from a grand-potential functional
• Phase field modeling of electrochemistry I: Equilibrium
• Phase-field simulations of lithium dendrite growth with open-source software
• Phase field modeling of electrochemistry II: Kinetics

Cited by in corpus (2)

• Morphological Stability of Metal Anodes: Roles of Solid Electrolyte Interphases (SEIs) and Desolvation Kinetics
• Nonequilibrium thermodynamic foundation of the grand-potential phase field model