skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on August 29, 2018

Title: In situ stress measurements during electrochemical cycling of lithium-rich cathodes

Layered lithium transition metal oxides (Li 1+xM 1-xO 2, M= Ni, Mn, Co) are attractive cathode materials for lithium-ion batteries due to their high reversible capacity but suffer from structural changes and voltage fade. In this study, we use stress as a novel way to track irreversible changes in Li 1.2Mn 0.55Ni 0.125Co 0.125O 2 (LR-NMC) cathodes. A unique and unpredicted stress signature is observed during the first delithiation. Initially, a tensile stress is observed, consistent with volume contraction from lithium removal, however, the stress reverses and becomes compressive with continued charging beyond 4 V vs Li/Li +, indicating volume expansion; this phenomenon is present in the first cycle only. The origin of this irreversible stress during delithiation is likely oxygen loss and the resulting cation rearrangement. Here, Raman spectroscopy provides evidence of the layered-to-spinel phase transition after cycling in the LR-NMC films, as well as recovery of the original spectra upon re-annealing in an oxygen environment.
Authors:
ORCiD logo [1] ;  [2] ;  [3] ; ORCiD logo [3] ; ORCiD logo [2] ;  [1]
  1. Brown Univ., Providence, RI (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Michigan State Univ., East Lansing, MI (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of Power Sources
Additional Journal Information:
Journal Volume: 364; Journal Issue: C; Journal ID: ISSN 0378-7753
Publisher:
Elsevier
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; 36 MATERIALS SCIENCE; Battery; Layered lithium-rich oxide; Thin film stress; Oxygen loss
OSTI Identifier:
1407794