Understanding the limitations of lithium ion batteries at high rates

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Authors

Colleges, School and Institutes

External organisations

  • University of Warwick

Abstract

Commercial lithium ion cells with different power: energy ratios were disassembled, to allow the electrochemical performance of their electrodes to be evaluated. Tests on coin cell half cells included rate tests (continuous and pulsed), resistance measurements, and extended pulse tests. Pulse power tests at high rates typically showed three limiting processes within a 10 s pulse; an instantaneous resistance increase, a solid state diffusion limited stage, and then electrolyte depletion/saturation. On anodes, the third process can also be lithium plating. Most of the cells were rated for a 10 C continuous discharge, and the cathode charging voltage at 10 C was around 4.2 V. For anodes, the maximum charge current to avoid a negative voltage was 3–5 C. Negative anode voltages do not necessarily mean that lithium plating has occurred. However, lithium deposits were observed on all the anodes after 5000 pulse sequences with 10 s pulses at ± 20 C.

Bibliographic note

Funding Information: This work was undertaken as part of a contract with the Advanced Propulsion Centre (www.apcuk.co.uk). WMG gratefully acknowledge this funding from APC. Publisher Copyright: © 2021 The Authors

Details

Original languageEnglish
Article number229690
Number of pages9
JournalJournal of Power Sources
Volume493
Early online date11 Mar 2021
Publication statusPublished - 1 May 2021