Abstract
Lithium-oxygen (Li-O2) batteries have attracted much attention owing to the high theoretical energy density afforded by the two-electron reduction of O2 to lithium peroxide (Li2O2). We report an inorganic-electrolyte Li-O2 cell that cycles at an elevated temperature via highly reversible four-electron redox to form crystalline lithium oxide (Li2O). It relies on a bifunctional metal oxide host that catalyzes O–O bond cleavage on discharge, yielding a high capacity of 11 milliampere-hours per square centimeter, and O2 evolution on charge with very low overpotential. Online mass spectrometry and chemical quantification confirm that oxidation of Li2O involves transfer of exactly 4 e–/O2. This work shows that Li-O2 electrochemistry is not intrinsically limited once problems of electrolyte, superoxide, and cathode host are overcome and that coulombic efficiency close to 100% can be achieved.
| Original language | English |
|---|---|
| Pages (from-to) | 777-781 |
| Number of pages | 5 |
| Journal | Science |
| Volume | 361 |
| Issue number | 6404 |
| DOIs | |
| State | Published - Aug 24 2018 |
| Externally published | Yes |
Funding
The authors thank V. Goodfellow and R. Smith at the University of Waterloo Mass Spectrometry Facility for their scientific input in the gas chromatography–mass spectrometry measurements. We also thank S. H. Vajargah for performing the TEM measurements. Research was supported by the Natural Sciences and Engineering Council of Canada through their Discovery and Canada Research Chair programs (L.F.N.), and a doctoral scholarship to C.Y.K. Partial funding for this work (C.Y.K.) was also provided by the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy Office of Science Basic Energy
| Funders | Funder number |
|---|---|
| Natural Sciences and Engineering Research Council of Canada |
