▎ 摘　　要

NOVELTY - Recycling cathode pole piece waste of lithium ion battery involves mixing leftover material and solvent in water bath or oil bath pot with temperature of 60-90 degrees C, stirring for 0.5-10 hours, where graphite is peeled off from copper foil, then filtering by ultrasonic vibration sieve to obtain graphite A, drying graphite A in drying box with temperature of 100-120 degrees C; drying until water content is less than 8%, obtaining graphite B', crushing and grading graphite B' according to size of grain diameter; adding concentrated sulfuric acid, graphite B4 and potassium permanganate in ratio of 40:1:0.5-6 to beaker and stir to mix, and then placing beaker in water bath with at 35 degrees C, stirring reaction in pot or oil bath for 4-6 hours, then taking beaker out of water bath or oil bath and stirring for 2-3 hours at room temperature to obtain graphite mixture. USE - Method for recycling lithium ion battery cathode pole piece waste. ADVANTAGE - The method enables to fully realizes recycling of graphite material on corner waste, avoids waste of resource and reduces production cost of enterprise; has good conductivity; improves performance of graphite charging and discharging; and improves multiplying power performance of cathode material. DETAILED DESCRIPTION - Recycling cathode pole piece waste of lithium ion battery involves mixing leftover material and solvent in water bath or oil bath pot with temperature of 60-90 degrees C, stirring for 0.5-10 hours, where graphite is peeled off from copper foil, then filtering by ultrasonic vibration sieve to obtain graphite A, drying graphite A in drying box with temperature of 100-120 degrees C; drying until water content is less than 8%, obtaining graphite B', crushing and grading graphite B' according to size of grain diameter; adding concentrated sulfuric acid, graphite B4 and potassium permanganate in ratio of 40:1:0.5-6 to beaker and stir to mix, and then placing beaker in water bath with at 35 degrees C, stirring reaction in pot or oil bath for 4-6 hours, then taking beaker out of water bath or oil bath and stirring for 2-3 hours at room temperature to obtain graphite mixture; combining graphite mixture to carry out centrifugal separation, washing obtained solid with deionized water until pH value is 7, and then centrifuging with pH value of 7 and separated solid is in vacuum environment at 80-130 degrees C, drying to moisture less than or equal to 6%; after drying, sending to microwave oven for microwave treatment for 3-15 minutes to obtain graphite with expanded interlayer spacing which is expanded graphite; expanding graphite which is mixed with N-Methyl-2-pyrrolidone (NMP) solvent to obtain mixed solution and above-mentioned mixed solution is mechanically stripped using nano sand mill to obtain pseudo-graphene solution with specific particle size distribution; adding graphite solution to homogenizer for homogenization to obtain graphene slurry with uniform particle size and thickness; mixing graphite B1 and graphite B2 according to 1:1 to obtain graphite C'; mixing graphite C', graphene slurry and graphite B3 in ratio of 0.5-2:7.5-9:0.5-1, then grinding and dispersed with high-speed disperser; adding polyvinylidene difluoride (PVDF) for mixing and granulation to obtain mixed material; placing mixed material in high-pressure filter press with pressure of 0.2-0.6 MegaPascal for filtration, and then passing filtered sieve through high-speed fusion shaping machine performs fusion shaping to obtain graphite-graphene composite material; placing graphite-graphene composite material in pusher type, roller type or rotating type at 1150-1500 degrees C in tunnel furnace, in high-purity nitrogen atmosphere, providing heat preservation for 1-19 hours to obtain negative electrode material.