A Three-dimensional thermal model for a commercial lithium-ion capacitor battery pack with non-uniform temperature distribution

Electrical energy storage is widely used not only in the mobile applications but also in stationary applications as like uninterruptable power supply. An energy storage system with the high energy density and high-power capability is very important for some specific applications like electric vehicles (EV). Lithiumion-batteries are well known for their high energy density while super-capacitors have high power capability. Lithium-ion capacitors (LiCs) which are a hybrid energy storage technology consisting of the lithium-ion batteries (LIBs) and super capacitors (SCs), combine the advantages of LIB and SC and eliminate their negative properties. However, the reliability of all types of energy storage technologies including LiCs can be drastically affected by overheating issues. These issues are more likely to happen in the closed casing battery pack. In this research, many experiments are performed to investigate the effect of current magnitude on the temperature distribution pattern in a module of 12 LiC cells. Then, in the COMSOL Multiphysics environment, a numerical solution is designed for a brief study of temperature distribution. The presented model accounts for different heat sources without getting into an electrochemical model. The simulation result shows a good agreement with the experimental results with an error of less than 5%. The presented model can be used to design a thermal management system with the focus on the hottest parts of the module.