A STUDY ON THE THERMAL BEHAVIOUR AND CAPACITY RECOVERY OF LITHIUM-ION BATTERIES AND THEIR THERMAL MANAGEMENT USING HEAT PIPES

Abstract

This thesis focuses on the modeling of lithium-ion batteries and their thermal management using heat pipes. A lumped-scale electrochemical-thermal cycle life model for lithium-ion battery is developed to predict open circuit voltages of cycled batteries and to evaluate the effect of temperature on the battery capacity loss. Later, a local-scale electrochemical-thermal model is developed to investigate the edge effect of cylindrical batteries and the feasibility of a proposed capacity recovery method for used/cycled batteries. The model is also employed to study the thermal performance of batteries highlighting the effect of thermal contact resistance. Suggestions on battery geometry optimizations are proposed to reduce the temperature gradient and the maximum temperature. Finally, experimental and numerical efforts are made to optimize a heat pipe thermal management system through sensitivity studies. The empirical study together with the modeling shows that the proposed system is capable for thermal management of batteries during fast charging.