Understanding and Improving Lithium Ion Battery Degradation: Modeling and Experiments

2^nd International Conference and Exhibition on Materials Science & Engineering

October 07-09, 2013 Hampton Inn Tropicana, Las Vegas, NV, USA

Rutooj D Deshpande

Accepted Abstracts: J Material Sci

Abstract :

Lithium ion batteries are under intense, worldwide research for improvement in durability and energy density for a wide range of applications, including electric and hybrid electric vehicles. Clear understanding of the battery capacity fading can lead to precise cycle-life prediction of batteries. For advanced lithium ion batteries with high energy and power performance, different aspects of lithium ion batteries such as novel electrode materials, improved electrode designs, Stabilizing electrolyte additives etc. are under high attention. When lithium is inserted in either the positive or negative electrode, the electrode material experiences mechanical stresses. Diffusion- induced stresses (DISs) can therefore cause the nucleation and growth of cracks leading to mechanical degradation of electrodes. We develop several mathematical models to study the behavior of diffusion induces stresses and effects of electrode shape, size, concentration dependent material properties, pre-existing cracks, phase transformations, operating conditions etc. on the diffusion induced stresses. Instability of commonly used electrolytes at the operating potentials leads to chemical degradation at the electrode surface. We study coupled chemical-mechanical degradation of electrode materials to understand the capacity fading of the battery with cycling. Chemical degradation can be decreased using electrolyte additives. We study the effect of electrolyte additive VC on parasitic reactions in Graphite/Lithium Nickel Manganese Cobalt Oxide (NMC) cells. Mechanical degradation can be avoided by use of novel electrode material such as liquid metal electrodes. We demonstrate that liquid metal electrodes can act as self-healing electrodes.

Biography :

Rutooj Deshpande has completed his Ph.D at the age of 25 years from University of Kentucky and is currently an electrochemical engineer postdoctoral fellow at Lawrence Berkeley National Laboratory, Berkley. His research focus is lithium ion battery degradation and improvement. He was the recipient of Graduate Excellence Material Science Diamond Award offered by American Ceramic Society (2011). He is on the reviewer panel of several journals Including Proceedings of National Academy of Science, Journal of Applies Physics, journal of Electrochemical Society.