▎ 摘　　要

NOVELTY - Graphene quantum dot composite material is prepared by mixing carbon source and solid carrier particles uniformly, and reacting at 45-80degrees Celsius for 30 minutes, where solid carrier particles are selected from additives acceptable for lead-acid batteries, such as sodium sulfate, titanium dioxide, barium sulfate, silicon dioxide, activated carbon, lead sulfate, nickel sulfate, bismuth oxide, nickel oxide, glass fiber, talc, or wollastonite. The mixture is heated to 180-220degrees Celsius to continue the reaction, or microwave treatment is performed to continue the reaction to obtain graphene quantum dot composite material. USE - Graphene quantum dot composite material is used in the preparation of lead-acid battery additives, and electrode material for lead ADVANTAGE - The graphene quantum dot composite material is a nanocomposite material synthesized in situ, size of quantum dot is uniformly distributed, uniformity is better, performance is more stable and controllable, has a large specific surface area, excellent conductivity, which increases contact area between electrode material and electrolyte, improves electronic conductivity of material to improve active site of reaction, which is good for improving reaction dynamics characteristic, so that electrochemical performance of materials in lead-acid battery is improved, and long life of the lead-acid battery secondary battery is realized. The synthesis process of graphene quantum dots is simple, time is shortened to less than 1 hour, and does not require use of strong acids, strong oxidants, etc., and solvents used in synthesis process are simply recycled for secondary use, and complicated purification operations are omitted. The synthesis cost of composite material is low, synthesis process is green and eco-friendly, and easy to realize industrialized production. The graphene quantum dot composite material is easily added to lead-acid battery to significantly increase life of lead-acid battery. The cycle life exceeds 2000 times under high-rate partial state of charge, and highest value reaches 12000 times. The graphene quantum dots contain sulfur, which is firmly combined with lead in lead-acid electrode material matrix during use, and battery reaction sites are fixed and uniform, at the same time, portion of sulfur is transformed into nano-lead sulfate, which acts as a seed crystal in the battery reaction to play a role of refining lead sulfate. The performance of lead-acid batteries is further improved. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) an electrode material for lead acid battery, which is uniformly mixed with graphene quantum dot composite material, where electrode material is a positive electrode material or a negative electrode material; and (2) a lead-acid battery, which comprises electrode material uniformly mixed with graphene quantum dot composite material.