Education

B.S., Chemical Engineering (2010)
Brigham Young University

Research Project:Capacity fade in lithium ion batteries

Research Summary:

Capacity and power fade in lithium-ion batteries are big concerns in applications requiring long-term use, such as electric vehicles (EVs) and satellites. These applications may require a battery life of 15 or more years. Experimental testing for such a long period of time is generally not viable due to the development of new materials with improved chemistry replacing the older materials used in batteries. With a physics-based degradation model, life prediction of lithium-ion batteries can be done with reasonable accuracy and experimental time can be reduced significantly using accelerated testing. Different degradation mechanisms including solvent reduction and interfacial film formation, active material dissolution, loss of contact between current collector and electrode, etc., are responsible for the decrease in energy and power capabilities of lithium-ion batteries. A better understanding of the degradation mechanisms is essential to incorporate into advanced lithium-ion battery models. We will use experimental techniques to understand and quantify the losses in capacity and power due to different failure mechanisms. We will develop a robust model to simulate and predict the performance of a typical lithium-ion battery used in a hybrid EV. Simulation results will be verified with experimental results obtained from tests performed on lithium-ion cells consisting of nickel cobalt manganese (NCM) cathode and graphite anode.