Phase-field modeling of chemo-mechanical relaxation effect on the fracture tolerance of a tin-based electrode

Xinlei Cao, Yongjun Lu, Hanqing Jiang, Fenghui Wang

Research output: Contribution to journalArticle

Abstract

The fracture phenomenon of high-capacity electrode materials during electrochemical cycles poses a major limitation on further advancements in Li-ion batteries. In this paper, a diffusion-creep-stress-fracture coupling model using the phase-field method is established to explore the chemo-mechanical relaxation effect on the fracture tolerance in a tin-based cylindrical electrode during lithiation. The results show that the creep relaxation mechanisms have twofold influence on the evolution of the multi-field system by altering the distribution of stresses. On the one hand, the relaxation mechanism which is crack size-dependent can improve the mechanical stability and fracture resistance of a tin-based electrode; on the other hand, the Li distributions accounting for creep are more uneven than those without creep, which may result in a reduction in usable capacity. Furthermore, the critical state of charge and its improvement for safe state due to creep relaxation are found to be size-dependent with regard to crack size. It can be associated to the stress concentration effect of flaws which can result in the earlier crack propagation and insufficient creep accumulation for a sharper (or longer) crack with large stress concentration.

Original languageEnglish (US)
Article number103502
JournalMechanics of Materials
Volume148
DOIs
StatePublished - Sep 2020

Keywords

  • Creep relaxation
  • Electrode fracture
  • Li-ion batteries
  • Phase-field method
  • Sn-based cylindrical electrode

ASJC Scopus subject areas

  • Materials Science(all)
  • Instrumentation
  • Mechanics of Materials

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