Understanding Side Reactions in K–O ₂ Batteries for Improved Cycle Life

Journal Article · Mon Oct 20 04:00:00 EDT 2014 · ACS Applied Materials and Interfaces

DOI:https://doi.org/10.1021/am505351s· OSTI ID:1392086

Ren, Xiaodi ^[1]; Lau, Kah Chun; Yu, Mingzhe ^[1]; Bi, Xuanxuan ^[1]; Kreidler, Eric ^[2]; Curtiss, Larry A.; Wu, Yiying ^[1]

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1. Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
2. Honda Research Institute USA, Inc., 1381 Kinnear Road, Columbus, Ohio 43212, United States

Superoxide based metal-air (or metal-oxygen) batteries, including potassium and sodium-oxygen batteries, have emerged as promising alternative chemistries in the metal-air battery family because of much improved round-trip efficiencies (>90%). In order to improve the cycle life of these batteries, it is crucial to understand and control the side reactions between the electrodes and the electrolyte. For potassium-oxygen batteries using ether-based electrolytes, the side reactions on the potassium anode have been identified as the main cause of battery failure. The composition of the side products formed on the anode, including some reaction intermediates, have been identified and quantified. Combined experimental studies and density functional theory (DFT) calculations show the side reactions are likely driven by the interaction of potassium with ether molecules and the crossover of oxygen from the cathode. To inhibit these side reactions, the incorporation of a polymeric potassium ion selective membrane (Nafion-K+) as a battery separator is demonstrated that significantly improves the battery cycle life. The K-O-2 battery with the Nafion-K+ separator can be discharged and charged for more than 40 cycles without increases in charging overpotential.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; USDOE Office of Science - Office of Basic Energy Sciences - Joint Center for Energy Storage Research (JCESR)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1392086
• Journal Information: ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 21 Vol. 6; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English