  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.
