A lithium battery including a negative electrode including a lithium metal or a lithium alloy; a positive electrode; and a polymer gel electrolyte contacting the negative electrode, wherein the polymer gel electrolyte has an ionic conductivity of about 10−3 S/cm or greater, a lithium ion transference number of about 0.15 or greater, and a lithium ion mobility of about 10−6 cm2/V×sec or greater, wherein the polymer gel electrolyte includes a lithium salt, a polymer capable of forming a complex with the lithium salt, an insulating inorganic filler, and an organic solvent, wherein the organic solvent is inert with respect to the lithium metal, wherein an anionic radius of the lithium salt is about 2.5 Angstroms or greater, and wherein a molecular weight of the lithium salt is about 145 or greater.