▎ 摘　　要

NOVELTY - The preparation method of graphene quantum dots involves: adding graphite powder into a concentrated nitric acid-concentrated sulfuric acid mixed acid according to the solid-liquid ratio of 1 g: 60-90 ml, stirring, and performing ultrasonic treatment to obtain a graphite dispersion liquid; placing the graphite dispersion liquid into a polytetrafluoroethylene high-pressure reaction kettle, sealing, carrying out hydrothermal reaction at 60-120 degrees Celsius for 6-24 hours, and standing for cooling; diluting the reaction liquid with deionized water, adding alkali to neutralize the reaction liquid to be neutral, and then standing the reaction liquid; filtering the reaction solution, and dialyzing the filtrate for 2-5 days using a dialysis bag; and freezing the dialyzed solution and drying in a freeze dryer. USE - Method for preparing graphene quantum dots used as electrolyte additive of a zinc ion battery (all claimed) ADVANTAGE - The graphene quantum dot additive has easily available raw materials, low cost, low toxicity, safety, and simple operation. The aqueous zinc ion battery electrolyte has higher large conductivity, can promote charge transfer of zinc ions, can effectively inhibit dissolution of a positive electrode material, reduce corrosion and hydrogen evolution rate of a zinc negative electrode, and effectively inhibit formation and growth of zinc dendrites, thus greatly improving the safety performance and cycle performance of the battery. The aqueous zinc ion battery containing the aqueous zinc ion battery electrolyte has excellent performance, can meet the technical requirement of electrochemical energy storage, and has wide application prospect. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) the graphene quantum dot prepared by the above method; (2) use of the graphene quantum dots as electrolyte additive of a zinc ion battery; (3) a zinc ion battery electrolyte comprising deionized water, a soluble zinc salt, and the graphene quantum dots; and (4) a zinc ion battery comprising a battery case, a positive electrode, a negative electrode, a diaphragm and the zinc ion battery electrolyte. DESCRIPTION OF DRAWING(S) - The drawing shows a rate performance curve obtained by performing charge and discharge cycles under different conditions in an aqueous zinc ion symmetric battery. (Drawing includes non-English language text).