Design-of-Experiments Analysis of Li-Ion Cell Capacity Fading in High Temperature Automotive Conditions

Stocker, Richard; Mumtaz, Asim; Lophitis, Neophytos

Abstract

This paper examines the evolution of performance degradation through capacity fade in Li-ion cells when subjected to 8 months of automotive drive cycles in high temperature conditions. This is done by combining a temperature controlled, highly transient cycling approach with a design-of-experiments matrix varying charge current magnitude and Depth-of-Discharge, two factors known to be influential in ageing rate. The subsequent results are then analyzed using design-of-experiments methodology and trend analysis, comparing the rates of capacity evolution at various points in cell lifetime. What was found is that the cell ageing evolved in 3 main phases dependent on the cycling timeduration rather than Ah throughput. In early life, charge current was influential, while in later life depth-of-discharge proved significant. It was also clear, that the factors could not be treated in isolation, with higher order and interaction effects observed. This implies that modeling of cell ageing cannot be uniform across lifetime and must consider the different ageing phases of the cell.

Citation

Stocker, R., Mumtaz, A., & Lophitis, N. (2019). Design-of-Experiments Analysis of Li-Ion Cell Capacity Fading in High Temperature Automotive Conditions. In 2019 Electric Vehicles International Conference (EV) (1-6). https://doi.org/10.1109/EV.2019.8893026

• Conference Name: 2019 Electric Vehicles International Conference (EV)
• Conference Location: Bucharest, Romania
• Start Date: Oct 3, 2019
• End Date: Oct 4, 2019
• Acceptance Date: May 8, 2019
• Online Publication Date: Nov 11, 2019
• Publication Date: 2019-10
• Deposit Date: May 5, 2020
• Publicly Available Date: May 14, 2020
• Publisher: Institute of Electrical and Electronics Engineers
• Pages: 1-6
• Book Title: 2019 Electric Vehicles International Conference (EV)
• ISBN: 9781728107929
• DOI: https://doi.org/10.1109/EV.2019.8893026
• Keywords: Lithium-ion, Battery cell, Equivalent circuit, Model, simulation
• Public URL: https://nottingham-repository.worktribe.com/output/4238082
• Publisher URL: https://ieeexplore.ieee.org/document/8893026
• Additional Information: © 2020 IEEE.Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.