Abstract

Commercial adoption of lithium-ion batteries (LIB) to power consumer electronics, transportation, and utility-grid applications is accelerating at a remarkable pace. State-of-the-art methods for managing LIB work well, but fall short in terms of being able to maximize a tradeoff between performance and aging. To unlock the full capability of LIB, existing empirical models must be replaced with physics-based models (PBMs) that describe the internal electrochemical variables that are predictors of future aging. A roadblock to using PBMs is the difficulty of estimating the model parameter values to fit the dynamics of a specific cell. Two primary approaches exist: one disassembles the cell and uses specialized equipment and experiments to measure parameter values directly; the second subjects an intact cell to different input-current stimuli and uses measured output voltage to regress estimates of model parameter values. This talk presents tradeoffs between these two approaches and focuses on methods that can produce estimates of all PBM parameter values without requiring cell disassembly.

Bio

Gregory L. Plett is a professor of electrical and computer engineering at the University of Colorado Colorado Springs (UCCS). His research focuses on applications of control-systems theory to the management of high-capacity battery systems such as found in hybrid and electric vehicles. Current investigations include physics-based reduced-order modeling of ideal lithium-ion and lithium-metal dynamics, system identification of physics-based model parameters using only current–voltage input–output data, physics-based reduced-order modeling of degradation mechanisms in electrochemical cells, estimation of cell internal state and degradation state, state-of-charge, state-of-health and state-of-life estimation. He offers courses in control systems and in battery modeling and management to support this research. Dr. Plett holds a bachelor of engineering degree in computer systems engineering from Carleton University (Ontario, Canada) and master of science and Ph.D. degrees in electrical engineering from Stanford University (Stanford, California). He is a senior member of the Institute of Electrical and Electronic Engineers and life member of the Electrochemical Society.