The effect of volume change and stack pressure on solid‐state battery cathodes

Boyang Liu, Shengda D. Pu, Christopher Doerrer, Dominic Spencer jolly, Robert A. House, Dominic L.R. Melvin, Paul Adamson, Patrick S. Grant, Xiangwen Gao*, Peter G. Bruce*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Downloads (Pure)

Abstract

Solid-state lithium batteries may provide increased energy density and improved safety compared with Li-ion technology. However, in a solid-state composite cathode, mechanical degradation due to repeated cathode volume changes during cycling may occur, which may be partially mitigated by applying a significant, but often impractical, uniaxial stack pressure. Herein, we compare the behavior of composite electrodes based on Li4Ti5O12 (LTO) (negligible volume change) and Nb2O5 (+4% expansion) cycled at different stack pressures. The initial LTO capacity and retention are not affected by pressure but for Nb2O5, they are significantly lower when a stack pressure of <2 MPa is applied, due to inter-particle cracking and solid-solid contact loss because of cyclic volume changes. This work confirms the importance of cathode mechanical stability and the stack pressures for long-term cyclability for solid-state batteries. This suggests that low volume-change cathode materials or a proper buffer layer are required for solid-state batteries, especially at low stack pressures.
Original languageEnglish
Pages (from-to)721-728
Number of pages8
JournalSusMat
Volume3
Issue number5
DOIs
Publication statusPublished - 8 Oct 2023

Bibliographical note

Acknowledgments:
Peter G. Bruce is indebted to the Henry Royce Institute SOLBAT (FIRG007 and FIRG008), as well as the Engineering and Physical Sciences Research Council, Enabling Next Generation Lithium Batteries (EP/M009521/1), and the Henry Royce Institute for Advanced Materials (EP/R0066X/1, EP/S019367/1, and EP/R010145/1) for financial support. Xiangwen Gao acknowledges financial support from the National Natural Science Foundation of China (22309110).

Keywords

  • cathode
  • interface
  • mechanical degradation
  • stack pressure
  • solid-state battery

Fingerprint

Dive into the research topics of 'The effect of volume change and stack pressure on solid‐state battery cathodes'. Together they form a unique fingerprint.

Cite this