A battery employing lithium-oxygen chemistry may include an anode comprising lithium, an electrolyte, and a porous cathode. The electrolyte may include a lithium-containing salt; a partially fluorinated ether, such as 2,2-bis(trifluoromethyl)-1,3-dioxolane; and a co-solvent selected from the group consisting of ethers, amides, nitriles, and combinations thereof. In some examples, the electrolyte does not include a cyclic carbonate ester, a sulfolane, or a sulfolane derivative. The porous cathode allows oxygen to come into contact with the electrolyte.