Computatonal Modeling of Nucleation at the Anode-Electrolyte Interface in Lithium Batteries

The Lithium (Li) Metal Battery (LMB), which possesses a Li Metal anode has come to the forefront of many researchers’ efforts to combat the energy storage limitations of the Li-Ion Battery (LIB). This is due to the large theoretical capacity that the Li metal anode (~3860 mA h g^-1) possesses in comparison with the graphite anode (~372 mA h g^-1) of the LIB. However, a main hindrance to the commercialization of these batteries is an unstable interface and uncontrolled dendrite growth, which pose serious safety concerns. While the growth process has been extensively studied, little is known about the nucleation process and how early nucleation effects dendrite growth throughout cycling. Due to the nature of the anode-electrolyte interface, it is difficult to study experimentally so we can use computational methods to resolve this interface and track the complex chemical and physical phenomena at this location. In this work we propose a computational model that uses a nucleation rate equation, stemming from Classical Nucleation Theory, to study how the electrochemical nucleation rate is impacted by varying parameters at the anode-electrolyte interface. The rate equation is then coupled with an extended, concentration dependent, Butler-Volmer equation to solve for the flux at the interface. Finally, the model is used to evaluate how surface energy impacts Li dendrite nucleation and growth.