On the Efficacy of Electrocatalysis in Nonaqueous Li-O2 Batteries

Authors
Bryan D. McCloskey,
Rouven Scheffler,
Angela Speidel,
Donald S. Bethune,
Robert M. Shelby,
Alan C. Luntz
Year of publication
2011
Journal
Journal of the American Chemical Society
Issue
45
Volume
133
Starting page
18038
Ending page
18041
Heterogeneous electrocatalysis has become a focal point in rechargeable Li–air battery research to reduce overpotentials in both the oxygen reduction (discharge) and especially oxygen evolution (charge) reactions. In this study, we show that past reports of traditional cathode electrocatalysis in nonaqueous Li–O2 batteries were indeed true, but that gas evolution related to electrolyte solvent decomposition was the dominant process being catalyzed. In dimethoxyethane, where Li2O2 formation is the dominant product of the electrochemistry, no catalytic activity (compared to pure carbon) is observed using the same (Au, Pt, MnO2) nanoparticles. Nevertheless, the onset potential of oxygen evolution is only slightly higher than the open circuit potential of the cell, indicating conventional oxygen evolution electrocatalysis may be unnecessary.
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