Rate-based degradation modeling of lithium-ion cells

Rate-based degradation modeling of lithium-ion cells

TitleRate-based degradation modeling of lithium-ion cells
Publication TypeJournal Article
Year of Publication2012
AuthorsEdward V Thomas, Ira Bloom, Jon P Christophersen, Vincent S Battaglia
JournalJournal of Power Sources
Volume206
378
Pagination378-382
Date Published05/2012
KeywordsAccelerated degradation testing, Life prediction, Non-isothermal stress
Abstract

Accelerated degradation testing is commonly used as the basis to characterize battery cell performance over a range of stress conditions (e.g., temperatures). Performance is measured by some response that is assumed to be related to the state of health of the cell (e.g., discharge resistance). Often, the ultimate goal of such testing is to predict cell life at some reference stress condition, where cell life is defined to be the point in time where performance has degraded to some critical level. These predictions are based on a degradation model that expresses the expected performance level versus the time and conditions under which a cell has been aged. Usually, the degradation model relates the accumulated degradation to the time at a constant stress level. The purpose of this article is to present an alternative framework for constructing a degradation model that focuses on the degradation rate rather than the accumulated degradation. One benefit of this alternative approach is that prediction of cell life is greatly facilitated in situations where the temperature exposure is not isothermal. This alternative modeling framework is illustrated via a family of rate-based models and experimental data acquired during calendar-life testing of high-power lithium-ion cells.

DOI10.1016/j.jpowsour.2012.01.106