Stress evolution in elastic-plastic electrodes during electrochemical processes: A numerical method and its applications

Jici Wen, Yujie Wei, Yang Tse Cheng

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

Monitoring in real time the stress state in high capacity electrodes during charge-discharge processes is pivotal to the performance assessment and structural optimization of advanced batteries. The wafer curvature measurement technique broadly employed in thin-film industry, together with stress analysis using the Stoney equation, has been successfully adopted to measure in situ the stress in thin film electrodes. How large plastic deformation or interfacial delamination during electrochemical cycles in such electrodes affects the applicability of Stoney equation remains unclear. Here we develop a robust electrochemical-mechanical coupled numerical procedure to investigate the influence of large plastic deformation and interfacial failure on the measured stress in thin film electrodes. We identify how the constitutive behavior of electrode materials and film-substrate interfacial properties affect the measured stress-capacity curves of electrodes, and hence establish the relationship of electrode material parameters with the characteristics of stress-capacity curves. Using Li-ions batteries as examples, we show that plastic deformation and interfacial delamination account for the asymmetric stress-capacity loops seen in in situ stress measurements. The methods used here, along with the finite-element code in the supplementary material, may be used to model the electrode behavior as a function of the state of charge.

Original languageEnglish
Pages (from-to)403-415
Number of pages13
JournalJournal of the Mechanics and Physics of Solids
Volume116
DOIs
StatePublished - Jul 2018

Bibliographical note

Publisher Copyright:
© 2018 Elsevier Ltd

Keywords

  • Battery mechanics
  • Electrochemical-mechanical coupling
  • Finite element method
  • In situ stress measurement
  • Interfacial delamination

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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