Localized high salt concentration electrolyte

A battery includes an electrolyte comprised of a solvating solvent, diluent, and a lithium salt. The electrolyte is a solution having a saturation point, the lithium salt being at least 5 times more soluble in the solvating solvent than in the diluent. The diluent and the solvating solvent are immiscible at a molar ratio of diluent/solvating solvent of 2 or more, and the solvating solvent and diluent are present in the electrolyte at a diluent/solvating solvent molar ratio of 0.1 to less than 2.