Issue 3, 2022

Probing heat generation and release in a 57.5 A h high-energy-density Li-ion pouch cell with a nickel-rich cathode and SiOx/graphite anode

Abstract

The electrochemical performance, reliability, and safety of Li-ion cells depend on thermal management. However, the heat generation mechanisms and release characteristics of large-format high-energy-density (HED) Li-ion cells, a prerequisite for an efficient battery thermal management system (TMS), remain unclear. This study clarifies the heat issues of a 57.5 Ah HED (266.9 W h kg−1) Li-ion cell with a promising material couple of nickel-rich cathode and SiOx/graphite anode. Both reversible entropic heat and irreversible polarization heat at different discharge rates are unraveled. While charge transfer and mass transport dominate the total polarization heat, the contribution from the ohmic effect and surface impedance increases with discharge rates. Polarization heat also increases consistently with lowering SOCs because of the increasing mass transport overpotential. In particular, the abrupt increase of heat generation at a SOC below 25% may be due to the leveraged discharge rate of SiOx caused by the mismatch of the voltage windows of graphite and SiOx. Moreover, the isothermal calorimetry study uncovers the significant heat accumulation and delayed heat release effects of large-format cells, which could cause undetectable but dangerous internal temperature rise at high discharge rates. Findings obtained in this study could guide the rational design of HED cells and TMS optimization.

Graphical abstract: Probing heat generation and release in a 57.5 A h high-energy-density Li-ion pouch cell with a nickel-rich cathode and SiOx/graphite anode

Supplementary files

Article information

Article type
Communication
Submitted
05 Okt. 2021
Accepted
30 Nov. 2021
First published
07 Dec. 2021

J. Mater. Chem. A, 2022,10, 1227-1235

Probing heat generation and release in a 57.5 A h high-energy-density Li-ion pouch cell with a nickel-rich cathode and SiOx/graphite anode

X. Qi, B. Liu, F. Yun, C. Wang, R. Wang, J. Pang, H. Tang, W. Quan, Q. Zhang, M. Yang, S. Wu, J. Wang and X. Sun, J. Mater. Chem. A, 2022, 10, 1227 DOI: 10.1039/D1TA08597B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements