Mechanical and Electrochemical Modeling and Simulation of Lithium-Ion Batteries

• Developed an electrochemical reduced order model (ROM) in MATLAB to simulate the battery voltage and heat generation rate, and achieved good accuracy and dramatically reduced computational cost in comparison with full order model• Wrote finite difference and finite volume codes in MATLAB to solve the solid diffusion and electrolyte transport equations• Created a thermo-electrochemical model in COMSOL to simulate the temperature, current collector potential and current density distributions in the cylindrical cells, and validated the model using experimentally measured voltages and temperatures

Thermal Modeling and Design of Lithium-Ion Batteries for Electric Vehicles• Estimated the specific heat capacity and anisotropic thermal conductivities of a pouch-type lithium-ion battery based on inverse heat transfer (IHT)• Created a 3D thermo-electrical model for a pouch-type lithium-ion battery to simulate the distributions of temperature, voltage, state of charge and current density inside the battery• Validated the model using measured temperatures and voltages for various discharge rates and environmental thermal conditions• Conducted sensitivity analysis to investigate relative importance of factors leading to non-uniform temperature distribution inside the battery, and clarified that the external heating or cooling from the tab is the dominating factor• Deduced a 2D analytical solution to the planar temperature distribution in the pouch-type battery using the integral transform technique, based on assumptions justified by the numerical model• Optimized the battery design (e. g. cell dimensions and tab position) to minimize the temperature rise and temperature non-uniformity using the 3D thermo-electrical model and multiple-objective genetic algorithm