Development of a Detailed Nucleation and Growth Model for CANTERA Implemented in Li-Air Batteries

Abstract

Heterogenous nucleation and growth (HNG) is the process by which dissolved species precipitate and adsorb on solid surfaces. HNG occurs as a prominent method mechanism in several systems, such as water filtration and metal-air batteries. Though it has been included in some model studies, wider adoption has been inhibited by a lack of standardized tools. The development of an open source CANTERA model for HNG provides a standardized framework for researchers to incorporate HNG while developing their models to an examine the impact of different chemistries on their systems.This presentation will demonstrate the HNG model with electrochemical impacts by applying it to an Li-Air battery model. Li-Air batteries are an important area of research in the energy storage field, as their high energy density could increase the range of electric vehicles to be comparable with current ICE vehicles. Despite the increase in interest, most models of Li-air batteries have relied on simplifying assumptions to represent deposition of Li₂O₂ [1], [2]. Preliminary 1D Li-O₂ model results using standard surface reaction rate forms are shown in Figure 1, demonstrating surface-limited reactions with increasing discharge rate. These will be compared to novel simulations with rate capabilities calculated using HNG kinetics. Additional results will examine the impact of precipitate morphology and catalyst loading. Model results will be presented alongside and experimental validation data. Figure 1: Preliminary 1D model results showing Li-O2 battery discharge at varying currents. Results show surface-area-limited discharge with increasing current density. These standard model results will be compared and contrasted to those using novel simulations with rates predicted by classical heterogeneous nucleation and growth theory.