Dynamic imaging of metastable reaction pathways in lithiated cobalt oxide electrodes

Qianqian Li, Jinsong Wu*, Zhenpeng Yao, Yaobin Xu, Michael M. Thackeray, Chris Wolverton, Vinayak P. Dravid

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Understanding how lithium-ion batteries function down to the atomic level during charge and discharge cycling can provide valuable guidance to optimize structure-property relationships and to design and understand new electrode materials. Lithium insertion and reactions with the electrodes during charge and discharge cycling can occur via metastable structures with complex ordering and related non-equilibrium phenomena. Remarkably, these processes remain still poorly understood despite their significance in the operation of lithium battery systems in critical technologies. In this communication, we present the dynamics of lithium insertion into Co3O4 and the evolution of metastable phases as probed by in-situ transmission electron microscopy, in concert with first principles density functional theory calculations. We show that the initial lithium intercalation reaction occurs with the formation of several metastable and intermediate phases, followed by a sequence of conversion reactions that perturb and expand the cubic-close-packed oxygen array, ultimately generating an end-product of finely dispersed cobalt metal clusters within a Li2O matrix. The calculated non-equilibrium lithiation pathways corroborate with the experimental lithiation voltages, and explain the significant hysteresis that occurs during electrochemical cycling. The data provide new insights into the complexity of solid state lithium electrochemistry in metal oxides that are relevant to advancing lithium battery technology.

Original languageEnglish (US)
Pages (from-to)15-22
Number of pages8
JournalNano Energy
Volume44
DOIs
StatePublished - Feb 2018

Keywords

  • Conversion reaction electrode
  • DFT calculation
  • In-situ lithiation
  • In-situ transmission electron microscopy
  • Lithium-ion battery
  • Metastable phase transformations

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Dynamic imaging of metastable reaction pathways in lithiated cobalt oxide electrodes'. Together they form a unique fingerprint.

Cite this