Computational Analysis of Battery Performance Working at Low Temperature

A demand for lithium ion batteries which able to operate under harsh condition (e.g. low temperature) is increasing due to its application for the electric vehicles. However, there are still technical bottlenecks for fabrication of a battery cell operating at low temperature. To solve this problem, various parameters and its effects for the kinetic mechanism during battery charge/discharge should be clarified. Computational approach is exploited to understand the relationship between performance of battery and kinetic parameters. In this study, we choose three independent parameters which affects to capacity and operating potential of the battery: the diffusion coefficient of lithium ion in active material, the lithiation constant at the surface of the active material and the particle radius of the active material. Based on pseudo-2D model, the capacity and the operating potential are calculated by varying diffusion coefficient, rate constant, and particle radius. Because diffusion coefficient and rate constant is dependent on temperature, the performance of battery drastically decline at certain temperature. From this theoretical basis, we calculate the particle radius of active material for maximizing the capacity and the optimal operating voltage at low temperature.