Toward Quantitative Phase-field Modeling of Dendritic Electrodeposition

TL;DR

This paper introduces a quantitative phase-field model for dendritic electrodeposition based on Marcus kinetics, enabling simulation of dendrite growth with experimental relevance and suggesting strategies for dendrite control in batteries.

Contribution

A novel phase-field model based on Marcus kinetics for concentrated solutions is developed, allowing for realistic simulation of dendritic growth during electrodeposition.

Findings

Model achieves quantitative agreement with zinc electrochemical kinetics.

Reducing exchange current density suppresses dendrite growth.

Screening electrolytes by exchange currents can control dendrite formation.

Abstract

A thin-interface phase-field model of electrochemical interfaces is developed based on Marcus kinetics for concentrated solutions, and used to simulate dendrite growth during electrodeposition of metals. The model is derived in the grand electrochemical potential to permit the interface to be widened to reach experimental length and time scales, and electroneutrality is formulated to eliminate the Debye length. Quantitative agreement is achieved with zinc Faradaic reaction kinetics, fractal growth dimension, tip velocity, and radius of curvature. Reducing the exchange current density is found to suppress the growth of dendrites, and screening electrolytes by their exchange currents is suggested as a strategy for controlling dendrite growth in batteries.