Understanding LiOH Chemistry in a Ruthenium-Catalyzed Li-O2 Battery.
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Peer-reviewed
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Non-aqueous Li-O2 batteries are promising for next-generation energy storage. New battery chemistries based on LiOH, rather than Li2 O2 , have been recently reported in systems with added water, one using a soluble additive LiI and the other using solid Ru catalysts. Here, the focus is on the mechanism of Ru-catalyzed LiOH chemistry. Using nuclear magnetic resonance, operando electrochemical pressure measurements, and mass spectrometry, it is shown that on discharging LiOH forms via a 4 e- oxygen reduction reaction, the H in LiOH coming solely from added H2 O and the O from both O2 and H2 O. On charging, quantitative LiOH oxidation occurs at 3.1 V, with O being trapped in a form of dimethyl sulfone in the electrolyte. Compared to Li2 O2 , LiOH formation over Ru incurs few side reactions, a critical advantage for developing a long-lived battery. An optimized metal-catalyst-electrolyte couple needs to be sought that aids LiOH oxidation and is stable towards attack by hydroxyl radicals.
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1521-3773
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European Commission (604391)
Engineering and Physical Sciences Research Council (EP/K01711X/1)
European Research Council (247411)
United States Department of Energy (DOE) (via University of California) (7057154)
Engineering and Physical Sciences Research Council (EP/L019469/1)
Technology Strategy Board (132220)
Engineering and Physical Sciences Research Council (EP/M009521/1)
Engineering and Physical Sciences Research Council (EP/K017144/1)