Understanding and Predicting Li Dendrite Formation in Li-Ion Batteries: Phase Field Model

Abstract

Lithium dendrite formation can lead the degradation and failure of Lithium ion battery, either because dendrite pieces lose electrical contract with the rest of the Li electrode (typically during Li stripping on discharge) or because growing dendrite can penetrate the separator and lead to internal short-circuiting. In this presentation, we will discuss a nonlinear phase-field model for the Li electrochemical deposition process to predict the conditions for dendrite formation along with their morphology. The model incorporates microstructure and evolution of the anode, the SEI (solid-electrolyte interphase layer) and the Li metal phase as functions of temperature, current density and history. It also describes the effect of electrode geometry on the nucleation and growth of Li-deposits. The simulation will suggest the optimum electrode geometry to prevent the Lithium dendrite formation. The 2D morphological evolution during Li deposition under different electrochemical conditions specified by charging current density, the ionic concentrations, reaction rate and applied potentials at the electrodes will be discussed.