Current Distribution Measurements in Parallel-Connected Lithium-Ion Cylindrical Cells under Non-Uniform Temperature Conditions

  • Klein M
  • Park J
57Citations
Citations of this article
79Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

© The Author(s) 2017. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND). Understanding internal state non-uniformity that occurs across the electrodes in large-format Lithium-ion batteries, and among parallel-connected cells, is a critical part of the cell and battery module design process. Two separate groups of parallel-connected 18650 cells were tested using LiFePO 4 /C 6 (LFP), and LiNiMnCoO 2 /C 6 (NMC) chemistries. Pulse and full-capacity discharges were performed at various States of Charge (SOC), C-rates, average temperatures, and levels of temperature non-uniformity. Current nonuniformity for the pulse testing was always lower for the LFP group compared to the NMC group. The hottest cell in the LFP group produced up to 40% more current than average, while this was up to 80% for NMC. Conversely, under charge depleting conditions the NMC group experienced less current non-uniformity, and in certain cases provided a nearly uniform current distribution in the presence of non-uniform temperature. The results indicate that higher temperature sensitivity in the impedance of a cell will cause larger current non-uniformity under pulse conditions. However, due to the presence of non-uniform SOC for charge depleting, the Open Circuit Voltage (OCV) versus SOC gradient plays a significant role in dictating the current distribution behavior, where steeper OCVs provide a corrective action that minimizes the effect of the non-uniform impedance.

Cite

CITATION STYLE

APA

Klein, M. P., & Park, J. W. (2017). Current Distribution Measurements in Parallel-Connected Lithium-Ion Cylindrical Cells under Non-Uniform Temperature Conditions. Journal of The Electrochemical Society, 164(9), A1893–A1906. https://doi.org/10.1149/2.0011709jes

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free