Analysis of precipitation effects in Li-S Batteries: Modeling, simulation, and experimental perspectives

In this article we analyze the precipitation effects in Li-S batteries using a novel mathematical model, finite-element simulations, and experimental measurements. The mathematical model describes the nucleation and growth of lithium sulfide in the cathode in terms of the local species concentration, which depend on the discharge rate of the battery. The model is written in the form of a differential system of equations that can be implemented in standard commercial or open-source finite element simulators. Sample simulation results for the discharge curves are presented and compared with experimental data for a Li-S battery, in which the cathode is made of freestanding carbon nanotubes and the active material (solid sulfur) is deposited more or less uniformly on the surface of the nanotubes. A good qualitative agreement is obtained between the simulation results and experimental data for the discharge rates between 0.1 C and 1 C.