Localized High-Salt-Concentration Electrolytes Containing Longer-Sidechain Glyme-Based Solvents and Fluorinated Diluents, and Uses Thereof

Localized high-salt-concentration electrolytes each containing a salt, a glyme as a solvent, and a fluorinated diluent. In some embodiments, the glyme has a chemical formula R—(O—CH—CH)—O—R, wherein n=1 to 4 and at least one of Rand Ris a hydrocarbon sidechain having at least 2 carbon atoms and wherein the salt is soluble in the glyme. In some embodiments, the fluorinated diluent is selected from the group consisting of a fluorinated glyme and a fluorinated ether. In some embodiments, the salt includes an alkali-metal salt. In some embodiments, the salt includes an alkali-earth-metal salt. The salt may include a perfluorinated sulfonimide salt. Electrochemical devices that include localized high-salt-concentration electrolytes of the present disclosure are also disclosed.