Electrochemical–Thermal Model of a Lithium-Ion Battery

Lithium-ion batteries are a promising type of energy storage for renewable energy applications owing to their high energy density. Extensive research has therefore been carried out, utilizing both experimental and computational methods to aid in a deeper understanding of these types of batteries. This research work presents an electrochemical–thermal computational model for lithium-ion battery cells that analyzes electrical behavior, chemical behavior and thermal behavior. This computational model is developed by implementing a finite volume solution of a set of partial differential equations that describe this behavior in the anode, separator and cathode. These differential equations are mass conservation, charge conservation and energy conversion. In addition, the Butler Volmer equation is used to describe the exchange of lithium ions between the solid electrodes and the electrolyte and empirical relationships are used to describe the equilibrium electrical potentials. The results obtained by the developed MATLAB program are validated against those published in the literature. On top of the comparisons, a number of additional results are generated using the developed computational tool such as profiles of the lithium-ion concentrations, profiles of the voltage and profiles of the temperature across the battery. In addition, the voltage output and temperature as a function of time for specified current flows are given. The effect of including a temperature simulating routine in the battery model is assessed. This work contributes toward the advancement of renewable and clean energy by providing a tool and results that can be used to better understand battery energy storage.