ENERGY CONVERSION AND BALANCE OF LI-ION BATTERY CELL WITH EMPHASIS ON HEAT GENERATION

The demand for clean energy storage has increased worldwide due to its intermittent nature. The heart of energy storage applications is the lithium (Li)-ion battery, especially for portable applications. However, high heat generation of Li-ion battery packs while cycling significantly affects overall performance, life, and safety. Therefore, maintaining battery temperature within the desired limits is essential. The primary goal of the current investigation is to analyze the process of energy conversion and quantify the heat generation in the Li-ion battery cell. The energy balance results give insight into possible areas for minimizing energy loss, which leads to improvement in performance. The Li-ion battery cell was tested at various rates of discharge to examine energy loss of the charge-discharge cycle. The findings show that energy loss rises as discharge rate increases, with heat generation accounting for the majority of energy loss. At 1C discharge rate, the energy loss as heat is 93.6%, while at 3C discharge rate energy loss as heat was estimated to be 60.0%. The results reveal that at lower discharge rates, the maximum energy loss is in the form of heat; however, at higher discharge rates, energy loss occurs as heat as well as other losses.