Nonaqueous Li-air batteries suffer from rechargeability limitations associated with both electrode and electrolyte instabilities.1-2 These instabilities could arise from various possible reasons, including thermal chemistry of Li2O2 with the solvent or electrode during discharge, or Li2O2-induced parasitic electrochemistry with cell components during charging. This presentation will highlight our current efforts to quantify Li2O2 formation during discharge and Li2O2 oxidation during charge.3 This analysis is combined with quantitative measurements of O2 consumption and evolution using DEMS, thus allowing us to more completely understand the parasitic processes that lead to limited Li-O2 cell rechargeability. We find that a chemical decomposition reaction between the electrolyte and Li2O2 account for nearly all efficiency losses on discharge, whereas both cathode and electrolyte electrochemical instabilities are observed on charge. We also observe that the amount of Li2O2 lost to parasitic reactions is similar on both discharge and charge, indicating that eliminating Li2O2-induced chemical decomposition of battery components is crucial for the development of a rechargeable Li-O2 battery.(1) McCloskey, B. D.; Bethune, D. S.; Shelby, R. M.; Mori, T.; Scheffler, R.; Speidel, A.; Sherwood, M.; Luntz, A. C. Limitations in Rechargeability of Li-O2 Batteries and Possible Origins. J. Phys. Chem. Lett. 2012 , 3043-3047.(2) McCloskey, B. D.; Speidel, A.; Scheffler, R.; Miller, D. C.; Viswanathan, V.; Hummelsh�j, J. S.; N�rskov, J. K.; Luntz, A. C. Twin Problems of Interfacial Carbonate Formation in Nonaqueous Li�O2 Batteries. J. Phys. Chem. Lett. 2012,  3, 997-1001.(3) 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. J. Phys. Chem. Lett. 2013,  4, 2989-2993.

Quantifying rechargeability limitations in Li-O<sub>2</sub> batteries

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Quantifying rechargeability limitations in Li-O2 batteries

Quantifying rechargeability limitations in Li-O₂ batteries