Electrolyte composition

An electrolyte composition for a secondary battery, comprising:

• zinc chloride, an alkali metal chloride, acetonitrile, and water,
• wherein the acetonitrile is present in a molality ranging from 6 mol/kg to 12 mol/kg, the zinc chloride is present in a molality ranging from 19 mol/kg to 40 mol/kg, and the alkali metal chloride is present in a molality ranging from 1 mol/kg to 22 mol/kg, based on the total weight of the water,
• wherein the secondary battery includes a positive electrode and a negative electrode disposed at intervals, a separator disposed between the positive electrode and the negative electrode, and an electrolyte which is formed by the electrolyte composition and which contacts the positive electrode and the negative electrode,
• wherein the positive electrode is selected from the group consisting of stainless steel tungsten, zinc, copper, lead, indium, lithium iron phosphate, sodium vanadium phosphate, lithium vanadium phosphate, potassium vanadium phosphate, and lithium manganite, and
• wherein the negative electrode is selected from the group consisting of zinc, copper, lead, tungsten, and indium.