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Title: Structure evolution and thermal stability of high-energy density Li-ion battery cathode Li 2VO 2F

Lithium-ion batteries (LIBs) provide high-energy-density electrochemical energy storage, which plays a central role in advancing technologies ranging from portable electronics to electric vehicles (EVs). However, a demand for lighter, more compact devices and for extended range EVs continues to fuel the need for higher energy density storage systems. Li 2VO 2F, which is synthesized in its lithiated state, allows two-electron transfer per formula during the electrochemical reaction providing a high theoretical capacity of 462 mAh/g. Herein, the synthesis and electrochemical performance of Li 2VO 2F are optimized. The thermal stability of Li 2VO 2F, which is related to the safety of a battery is studied by thermal gravimetric analysis. The structure and vanadium oxidation state evolution along Li cycling are studied by ex-situ X-ray diffraction and absorption techniques. It is shown that the rock-salt structure of pristine Li 2VO 2F is stable up to at least 250°C, and is preserved upon Li cycling, which proceeds by the solid-solution mechanism. However, not all Li can be removed from the structure upon charge to 4.5 V, limiting the experimentally obtained capacity.
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [4] ;  [5] ;  [5] ;  [1] ;  [6]
  1. Binghamton Univ., NY (United States). NorthEast Center for Chemical Energy Storage (NECCES)
  2. Binghamton Univ., NY (United States). Dept. of Chemistry and Materials
  3. Binghamton Univ., NY (United States). NorthEast Center for Chemical Energy Storage (NECCES); Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
  4. Binghamton Univ., NY (United States). NorthEast Center for Chemical Energy Storage (NECCES); Binghamton Univ., NY (United States). Dept. of Physics, Applied Physics and Astronomy
  5. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
  6. Binghamton Univ., NY (United States). NorthEast Center for Chemical Energy Storage (NECCES); Binghamton Univ., NY (United States). Dept. of Chemistry and Materials
Publication Date:
Grant/Contract Number:
AC02-06CH11357; SC0012583; SC0012704
Type:
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 164; Journal Issue: 7; Journal ID: ISSN 0013-4651
Publisher:
The Electrochemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (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; Cathode materials; Li-ion battries; Reaction mechanism; Thermal stability
OSTI Identifier:
1367893