a positive electrode and a negative electrode arranged opposite to each other;

a separator interposed between the positive electrode and the negative electrode; and

an electrolyte solution which is impregnated in the positive electrode, the negative electrode and the separator,

wherein the electrolyte solution has ion conductivity, and

wherein the electrolyte solution comprises:

a lithium polysulfide;

a non-aqueous solvent consisting of an ether solvent, which is a mixture of a linear ether and a cyclic ether, wherein the cyclic ether comprises at least one selected from the group consisting of dioxolane, methyldioxolane, dimethyldioxolane, vinyldioxolane, methoxydioxolane, ethylmethyldioxolane, dioxane, and trioxane; and

a lithium salt, wherein the lithium salt consists of LiBr,

wherein the concentration of the lithium salt is in a range of 1M to 4M,

wherein the electrolyte comprises dissolved lithium polysulfide that is obtained by the reaction of sulfur and lithium sulfide prior to the operation of the battery.