Enhancing precision in two-dimensional lithium battery modeling using an improved discharge boundary condition setting within the lattice Boltzmann method framework for broad applications

To enhance the modeling accuracy of the two-dimensional lithium battery model and improve its precision in predicting the discharge process, this study proposes an approach based on a new discharge boundary condition setting. In this method, when a battery is connected to a load circuit, electrochemical reactions occurring at the interface between the electrode particles and the electrolyte induce uniform changes in the surface potentials of all electrode particles in the cathode and anode regions, rather than being confined to the battery terminals near the current collectors. These changes are quantified based on the load current using an optimization algorithm, instead of conductivity calculations. Leveraging this approach, a two-dimensional battery model is developed within an improved lattice Boltzmann method framework. Simulation results reveal that the model satisfies current and charge conservation principles, substantially improves computational accuracy, and demonstrates high stability. Furthermore, the two-dimensional local variations in lithium/lithium-ion concentrations predicted by the model align well with the general mechanism analysis. Notably, this model demonstrates versatility for broad applications, effectively predicting battery behavior under varied discharge conditions, such as constant-current and constant-resistance discharge modes, and can handle electrode particle size heterogeneity.