Thermal modelling of cylindrical Lithium-Ion batteries to study the impact of structural components

Temperature has a profound impact on the performance of lithium-ion batteries. The temperature distribution in the cylindrical cell during charging and discharging cycles is governed by physical features of materials such as thermal conductivity and specific heat capacity. The cells must operate at their optimal temperature. The eight thermal models were build by finite element analysis on the COMSOL Multiphysics 5.6 software. With inputs and average characteristics such as open-circuit voltage (OCV), state of charge (SOC), thermal conductivities, specific heat capacities, and density of the materials employed, the software develops a two-dimensional thermal model. The thermal model is designed to work with a cylindrical 18 650 lithium-ion battery. The cell's initial temperature is 298.15 K. After the simulation, the results are interpolated to the 1500s. The thermal distribution in the axial and radial directions is investigated, with the conclusion that certain elements have a greater impact on the cell temperature distribution. The results show that the temperature distributions of the cell are greatly influenced by the steel case around the cylindrical structure, steel needle, electrolyte filled in between the cavities, and relief valve.