Battery Stress Factor Ranking for Accelerated Degradation Test Planning Using Machine Learning

Abstract

Lithium-ion batteries power numerous systems from consumer electronics to electric vehicles, and thus undergo qualification testing for degradation assessment prior to deployment. Qualification testing involves repeated charge–discharge operation of the batteries, which can take more than three months if subjected to 500 cycles at a C-rate of 0.5C. Accelerated degradation testing can be used to reduce extensive test time, but its application requires a careful selection of stress factors. To address this challenge, this study identifies and ranks stress factors in terms of their effects on battery degradation (capacity fade) using half-fractional design of experiments and machine learning. Two case studies are presented involving 96 lithium-ion batteries from two different manufacturers, tested under five different stress factors. Results show that neither the individual (main) effects nor the two-way interaction effects of charge C-rate and depth of discharge rank in the top three significant stress factors for the capacity fade in lithium-ion batteries, while temperature in the form of either individual or interaction effect provides the maximum acceleration.

Effect of Ambient Temperature and Discharge Current on Thermo-Electrochemical Behaviour of Lithium-Ion Cells Using Surrogate Modelling and Analysis

“…The current rate and ambient temperature have been regarded to be the two major factors that have the most effect on the thermo-electrochemical performance of these cells. 27 Various researchers have conducted studies to understand the thermal response of the cells. Morali 28 performed thermal simulations to gain insights into the thermal dynamics of cells.…”

“…Also, it was reported that the discharge current has a major role in the rise in temperature of the cell, and the SOH is the least contributor to the rise in temperature compared to other considered design parameters. Saxena et al 27 studied the effect of different parameters such as charge current cutoff, discharge current rate, depth of discharge, ambient temperature and the combined effect of these parameters in the stress factor ranking of the cells using the data-driven modelling techniques. They reported that the individual and combined effect of z E-mail: agupta@mech.iitd.ac.in discharge current and ambient temperature causes maximum stress on the cell capacity compared to other reported stress factors.…”

Review of Battery Energy Storage Systems Modeling in Microgrids with Renewables Considering Battery Degradation

“…The effect of these stress factors on battery degradation, however, is not uniform, and some factors may have a disproportionately strong effect on degradation. A multi-factor experimental study [59] investigated the significance and ranking of the individual (main) and two-way interaction effects of all five stress factors (ambient temperature, discharge C-rate, charge C-rate C, DOD, and charge cut-off) that are necessary to compose a typical cyclic operation that is used in battery qualification tests. However, the stress-factor ranges in the experimental design were chosen with an emphasis on portable electronics.…”

“…The most significant factors affecting capacity fading in [59] were temperature, discharge rate, and constant charge voltage as either their separate effects or those of their interaction. The study notes that the charge cut-off during the constant-voltage charging phase, an important parameter during battery charging that is underrepresented in the published research on batteries, was more dominant for battery degradation compared to the charge cut-off that was used during the constant-current charging phase.…”

Development of an Informative Lithium-Ion Battery Datasheet

“…Commercial lithium-ion batteries have been the dominant power supply for today's consumer electronics and high-power and energy mobile systems [1,2]. A technical specification sheet (datasheet) is a document that prescribes technical requirements to be fulfilled by a product, process, or service [3], is needed to choose and use a lithium-ion battery.…”