Perfluorocarbon compounds (PFC) are known for their high O-2 dissolution capability and have been investigated as additives/electrolyte solvents to improve Li-O-2 batteries performance. Nevertheless, systematic studies that go beyond the proof of concept that fluorocarbon additives enhance the performance of Li-O-2 batteries have not been carried out yet. In this work, we investigate 1-methoxyheptafluoropropane additive (1-PFC), a fluorocarbon with an ether functional group that has been considered as one of the candidates as additives in the Li-O-2 battery. Using electrochemical methods and physical characterization of discharge products, we found that the enhancement of the discharge capacity of Li-O-2 cells with 1-PFC additive is most likely correlated with instability of the 1-PFC additive against superoxide radicals, rather than the improvement in O2 solubility. (C) 2016 The Electrochemical Society. All rights reserved.