Yongquan Sun1,2, Saurabh Saxena2, and Michael Pecht2
1 Institute of Sensor and Reliability Engineering (ISRE), Harbin University of Science and Technology, Harbin 150080, China
2 CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
Derating is widely applied to electronic components and products to ensure or extend their
operational life for the targeted application. However, there are currently no derating guidelines
for Li-ion batteries. This paper presents derating methodology and guidelines for Li-ion batteries
using temperature, discharge C-rate, charge C-rate, charge cut-off current, charge cut-off voltage, and
state of charge (SOC) stress factors to reduce the rate of capacity loss and extend battery calendar life
and cycle life. Experimental battery degradation data from our testing and the literature have been
reviewed to demonstrate the role of stress factors in battery degradation and derating for two widely
used Li-ion batteries: graphite/LiCoO2 (LCO) and graphite/LiFePO4 (LFP). Derating factors have
been computed based on the battery capacity loss to quantitatively evaluate the derating effects of
the stress factors and identify the significant factors for battery derating.
This article is available online here and to CALCE Consortium Members for personal review.