Electro-Thermal Modeling of a Hollow Structure Design of Cylindrical Lithium-Ion Battery

Thermal management of the lithium-ion battery is important for battery performance and safety. The traditional cylindrical lithium-ion battery has temperature unevenness problem, especially when operating at high rate. The difference between measurable surface temperature and maximum temperature of the battery may be large. A hollow structure design of the cylindrical lithium-ion battery is proposed. The hollow cylinder structure has the advantages of better cooling performance and the convenience of putting temperature sensors inside of the battery. The battery model coupled with electrochemical model and thermal model is established. Thermal states of the hollow battery and the solid battery under air cooling condition are simulated for comparison. Results show that the maximum temperature of charging hollow battery is lower and the temperature unevenness problem is also improved. At higher charge rate, the advantages of the hollow cylinder structure become more significant. When the inner diameter increases, the total volume of the hollow battery becomes larger quickly, leading to lower volume energy density. The conflict between this drawback and advantages of lower maximum temperature and better temperature unevenness is analyzed.