Electro-thermal modeling of Lithium-ion cell for higher discharge rate applications

Lithium-ion batteries are most preferable energy storage devices for its higher energy density, flexible form factor and light weight design than comparable battery technologies. Considerations of thermal effects in Lithium-ion cells (related to cycle and calendar life) are important for the safety issues because higher temperature may leads to the thermal runaway. Electro-thermal modeling enables us to understand the thermal behaviour of cells, quantification of heat generation inside the cell and changes in cell chemistry at the time of battery operation. The various electro-thermal models of Lithium-ion cells have been investigated using methods like control volume, finite elementary, differential method. Substantial diagnostic and practical modeling efforts are required to fully understand the thermal and electrical characteristics of the Lithium-ion cells across various operating conditions for higher discharge rate. Higher discharge rate (approximately 10C) is preferred for some particular application like Torpedo, underwater vehicles etc. Several factors associated with cell fabrications, such as electrode thickness, compactness, electronic conductivity etc, need to be optimized to achieve better cell performance at higher discharge rate. Thermal behaviour of the cell at high discharge rate is another important issue that must be address properly to mitigate safety related concerns.