Mechanistic Insights into Rechargeability and Capacity Limitations in Nonaqueous Li-O2 Batteries

Li-air batteries have received significant attention as a potential high specific energy alternative to current state-of-the-art rechargeable Li-ion batteries.^1-3 However, numerous scientific challenges remain unsolved in the pursuit of attaining a battery with high capacity and modest Coulombic efficiency.  This presentation will highlight efforts to improve Li-air battery cyclability and capacity through studies that elucidate the mechanism of Li₂O₂ electrochemical formation and oxidation at the positive electrode.  Results will be presented confirming that Li-O₂ battery capacity is limited by Li₂O₂-induced cathode electronic insulation and rechargeability is limited by electrolyte and electrode instabilities in the presence of Li₂O₂.^4-5 Strategies to circumvent both of these challenges will be discussed.⁶

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(2)  Girishkumar, G.; McCloskey, B.; Luntz, A. C.; Swanson, S.; Wilcke, W. Lithium−air battery: promise and challenges. J. Phys. Chem. Lett. 2010, 1, 2193-2203.

(3)  Christensen, J.; Albertus, P.; Sanchez-Carrera, R. S.; Lohmann, T.; Kozinsky, B.; Liedtke, R.; Ahmed, J.; Kojic, A. A critical review of Li/air batteries. J. Electrochem. Soc. 2012, 159, R1-R30.

(4)  McCloskey, B. D.; Valery, A.; Luntz, A. C.; Gowda, S. R.; Wallraff, G. M.; Garcia, J. M.; Mori, T.; Krupp, L. E. Combining accurate O₂ and Li₂O₂ assays to separate discharge and charge stability limitations in nonaqueous Li-O₂ batteries. Journal of Physical Chemistry Letters 2013, 4, 2989- 2993.

(5)  Viswanathan, V.; Thygesen, K. S.; Hummelshoj, J. S.; Norskov, J. K.; Girishkumar, G.; McCloskey, B. D.; Luntz, A. C. Electrical conductivity in Li₂O₂ and its role in determining capacity limitations in non-aqueous Li-O₂ batteries. J. Chem. Phys. 2011, 135, 214704.

(6)  Luntz, A. C.; McCloskey, B. D. Nonaqueous Li–air batteries: a status report. Chemical Reviews 2014, Article ASAP.