Lithium ion battery anode functional coating and preparation method thereof

Abstract

The invention provides a lithium ion battery anode functional coating and a preparation method thereof. A dispersing agent NMP (N-methyl-pyrrolidone) is stirred by a planetary stirrer at a high speed till the temperature reaches 40 to 50 DEG C; a certain proportion of a binding agent PVDF (Polyvinylidene Fluoride) is added to enable the solid content of a binding agent solution to be 1.2 to 3.5 percent; low-speed revolution is performed and then high-speed rotation is started; cold circulating water is received to control the temperature of the slurry below 50 DEG C; stirring is preformed for 2 to 6 h; a carbon black conductive agent (conductive carbon) is added to enable the solid contend of the slurry to be 20 to 30 percent; stirring is performed for 2 to 4 h; the slurry is transferred into a high-efficiency dynaflow ultrasonic slurry mixer to be subjected to ultrasonic dispersion for 1 to 2 h; after the preparation is finished, the slurry passes through a 200-mesh screen stencil and is sprayed through a spraying machine, wherein the spraying thickness is controlled within 3 to 5 Mum; and after the spraying is finished, a coated pole piece is baked for 12 to 14 h at 110 plus or minus 3 DEG C, wherein dry nitrogen is filled for replacement once each two hours, so as to obtain the lithium ion battery anode functional coating. The replacement of a current collector with an anode aluminium foil material by a current collector with the functional coating can greatly improve the electrochemical properties of lithium ion batteries.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery cathodes, and relates to a lithium-ion battery cathode functional coating and a preparation method thereof. Background technique [0002] Due to the advantages of high voltage, high specific energy, long cycle life, no memory effect, good safety performance and less environmental pollution, lithium-ion batteries have great potential in portable electronic equipment, electric vehicles, space technology, defense industry and other fields. Wide application prospects. With the stringent demand for high power density of lithium-ion batteries put forward by electric tools and small power equipment, higher-quality power lithium-ion batteries are required. At present, whether it is lithium iron phosphate positive electrode system, nickel cobalt lithium manganese oxide positive electrode system or lithium manganese oxide positive electrode system, the lithium ion battery manufacturing process ...

AI Technical Summary

Problems solved by technology

At present, the 18650-rate lithium iron phosphate lithium-ion battery at home and abroad has a nominal capacity of 1300mAh, and the 30C continuous discharge capacity is less than 90% of the 0.5C discharge capacity, and the high-rate cycle performance is poor, and the 5C charge-discharge cycle life is less than 1000 times

18650 rate type nickel-cobalt lithium manganese oxide battery, nominal capacity 1300mAh, 3C charge 10C discharge cycle life is poor, less than 1000 times, the inside of the battery that has been cycled for a long time is severely damaged and cannot be recovered, and the lithium-ion batteries of each positive electrode system All performance needs to be further improved

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