Electrochemical-mechanical modeling of solid polymer electrolytes: Stress development and non-uniform electric current density in trench geometry microbatteries

Davide Grazioli, Vahur Zadin, Daniel Brandell, Angelo Simone

Research output: Contribution to journalArticleScientificpeer-review

11 Citations (Scopus)
111 Downloads (Pure)

Abstract

We study the effect of mechanical stresses arising in solid polymer electrolytes (SPEs) on the electrochemical performance of lithium-ion (Li-ion) solid-state batteries. Time-dependent finite element analyses of interdigitated plate cells during a discharge process are performed with a constitutive model that couples ionic conduction within the SPE with its deformation field. Due to the coupled nature of the processes taking place in the SPE, the non-uniform ionic concentration profiles that develop during the discharge process induce stresses and deformations within the SPE; at the same time the mechanical loads applied to the cell affect the charge conduction path. Results of a parametric study show that stresses induced by ionic redistribution favor ionic transport and enhance cell conductivity—up to a 15% increase compared to the solution obtained with a purely electrochemical model. We observe that, when the contribution of the mechanical stresses is included in the simulations, the localization of the electric current density at the top of the electrode plates is more pronounced compared to the purely electrochemical model. This suggests that electrode utilization, a limiting factor for the design of three-dimensional battery architectures, depends on the stress field that develops in the SPE. The stress level is indeed significant, and mechanical failure of the polymer might occur during service.
Original languageEnglish
Pages (from-to)1142-1162
Number of pages21
JournalElectrochimica Acta
Volume296
DOIs
Publication statusPublished - 2019

Keywords

  • Battery performance
  • Electrochemical-mechanical coupling
  • Non-uniform electric current density
  • Solid polymer electrolytes
  • Trench geometry microbattery

Fingerprint Dive into the research topics of 'Electrochemical-mechanical modeling of solid polymer electrolytes: Stress development and non-uniform electric current density in trench geometry microbatteries'. Together they form a unique fingerprint.

  • Cite this