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Title: Nanostructured metal carbides for aprotic Li-O 2 batteries. New insights into interfacial reactions and cathode stability

The development of nonaqueous Li–oxygen batteries, which relies on the reversible reaction of Li + O 2 to give lithium peroxide (Li 2O 2), is challenged by several factors, not the least being the high charging voltage that results when carbon is typically employed as the cathode host. We report here on the remarkably low 3.2 V potential for Li 2O 2 oxidation on a passivated nanostructured metallic carbide (Mo 2C), carbon-free cathode host. Furthermore, online mass spectrometry coupled with X-ray photoelectron spectroscopy unequivocally demonstrates that lithium peroxide is simultaneously oxidized together with the Li xMoO 3-passivated conductive interface formed on the carbide, owing to their close redox potentials. We found that the process rejuvenates the surface on each cycle upon electrochemical charge by releasing Li xMoO 3 into the electrolyte, explaining the low charging potential.
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1]
  1. Univ. of Waterloo, ON (Canada)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1948-7185; 590459
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 6; Journal Issue: 12; Journal ID: ISSN 1948-7185
American Chemical Society
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
25 ENERGY STORAGE; lithium-air; oxygen reduction; aprotic medial online mass spectrometry