▎ 摘　　要

NOVELTY - A zinc ion secondary battery (100) comprises a 1st electrode; 2nd electrode; and electrolyte (160) disposed between 1st electrode and 2nd electrode, where active material in 1st electrode is alkali metal-vanadium oxide/graphene oxide composite, where the alkali metal-vanadium oxide has a layered structure in which alkali metal layers and vanadium oxide layers are alternately laminated. USE - A zinc ion secondary battery. ADVANTAGE - The zinc ion battery system including metal-vanadium oxide/graphene oxide composite as electrode active material can exhibit excellent rechargeability and have high discharge capacity and an excellent capacity retention rate. The electrode active material of zinc ion secondary battery is ecofriendly and inexpensive and has high stability. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) electrode active material comprising vanadium oxide particles; and a graphene oxide sheet for fixing the vanadium oxide particles, where the vanadium oxide particles have an alkali metal-vanadium oxide including a layered structure in which alkali metal layers and vanadium oxide layers are alternately laminated; and (2) preparing the electrode active material which involves preparing a solution comprising a vanadium oxide, an alkali compound, and a solvent; adding a reduced graphene oxide to the solution to prepare a mixture; and performing solvothermal synthesis by feeding the mixture into a closed reactor and heat-treating at a temperature of a boiling point of the solvent or higher. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the secondary battery. Zinc ion secondary battery (100) 2nd electrode active material layer (120) Separator (130) 1st electrode active material layer (140) Electrolyte (160)