Anode slurry of high-rate lithium ion battery and fabrication method of anode slurry

Abstract

The invention discloses anode slurry of a high-rate lithium ion battery and a fabrication method of the anode slurry. The fabrication method comprises the steps of mixing a binder, a conductive agent and a lithium iron phosphate active substance uniformly at a mass ratio of 1:(0.8-1.2):(18-23) with a mixer at a rotating speed of 19-21r / min for 2-4h, adding the uniformly mixed raw materials into an air blowing oven for baking at 80-90 DEG C for 8-12h, turning off the air blowing oven, cooling the mixed raw materials naturally to below 45 DEG C for use, adding the raw materials into a stirring barrel containg NMP (N-Methyl Pyrrolidone) in three times, stirring with a planetary stirrer, controlling the solid content of the slurry to be 30%-40%, stirring for 5-10min at a low speed and 1-1.5h at a high speed when the mixed raw materials are added in the first time and the second time, stirring for 5-10min at the low speed and 2-3h at the high speed when the mixed raw materials are added in the third time, adding NMP to adjust viscosity, controlling the viscosity to be 5000-10000MPa*s, stirring at the low speed to conduct vacuum defoaming, and filtering the slurry with a screen with 200 meshes.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a high-rate lithium ion battery cathode slurry and a preparation method thereof. Background technique [0002] Lithium iron phosphate lithium-ion battery has a wide range of application prospects in the field of power technology due to its high power density, long cycle life, good safety performance and environmental friendliness. With the continuous improvement of the performance requirements of electric tools and small power equipment for lithium-ion batteries, the performance of lithium iron phosphate lithium-ion batteries has been continuously improved. The raw materials of high-rate lithium-ion batteries require good conductivity. People usually use conductive graphite and conductive carbon black with moderate specific surface area as the positive electrode conductive agent of the battery to improve the rate energy of the battery. For the conductive...

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Problems solved by technology

The conductive agent with excellent electrical conductivity has a large specific surface area, is not easy to disperse, and cannot improve the dispersibility of the material by reducing the solid content of the slurry, which will lead to low viscosity of the slurry, and the stirring speed is not easy to be too fast. If the stirring speed is high, the shear stress will be large. , will also reduce the viscosity of the slurry