Elucidating and Mitigating High-Voltage Interfacial Chemomechanical Degradation of Nickel-Rich Lithium-Ion Battery Cathodes via Conformal Graphene Coating

Norman S. Luu, Jin Myoung Lim, Carlos G. Torres-Castanedo, Kyu Young Park, Elahe Moazzen, Kun He, Patricia E. Meza, Wenyun Li, Julia R. Downing, Xiaobing Hu, Vinayak P. Dravid, Scott A. Barnett, Michael J. Bedzyk, Mark C. Hersam*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Lithium nickel manganese cobalt oxides (NMCs) are promising cathode materials for high-performance lithium-ion batteries. Although these materials are commonly cycled within mild voltage windows (up to 4.3 V vs Li/Li+), operation at high voltages (>4.7 V vs Li/Li+) to access additional capacity is generally avoided due to severe interfacial and chemomechanical degradation. At these high potentials, NMC degradation is caused by exacerbated electrolyte decomposition reactions and non-uniform buildup of chemomechanical strains that result in particle fracture. By applying a conformal graphene coating on the surface of NMC primary particles, we find significant enhancements in the high-voltage cycle life and Coulombic efficiency upon electrochemical cycling. Postmortem X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy suggest that the graphene coating mitigates electrolyte decomposition reactions and reduces particle fracture and electrochemical creep. We propose a relationship between the spatial uniformity of lithium flux and particle-level mechanical degradation and show that a conformal graphene coating is well-suited to address these issues. Overall, these results delineate a pathway for rationally mitigating high-voltage chemomechanical degradation of nickel-rich cathodes that can be applied to existing and emerging classes of battery materials.

Original languageEnglish (US)
Pages (from-to)11069-11079
Number of pages11
JournalACS Applied Energy Materials
Volume4
Issue number10
DOIs
StatePublished - Oct 25 2021

Keywords

  • Coulombic efficiency
  • battery cathode
  • chemomechanical degradation
  • cycle life
  • electrochemical creep
  • high voltage
  • lithium nickel manganese cobalt oxide

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Energy Engineering and Power Technology
  • Electrochemistry
  • Electrical and Electronic Engineering
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Elucidating and Mitigating High-Voltage Interfacial Chemomechanical Degradation of Nickel-Rich Lithium-Ion Battery Cathodes via Conformal Graphene Coating'. Together they form a unique fingerprint.

Cite this