Ultrasonic stirring apparatus for lithium ion battery electrode slurry

Abstract

Stirring homogenate is a key process during manufacture of a lithium ion secondary battery, and aims at homogenizing a slurry as much as possible. A present widely-known technology employs a motor for driving a stirring paddle for stirring the slurry, the stirring intensity generated by the stirring manner is not uniform in different positions in a slurry barrel, especially when the slurry viscosity is relatively high and the slurry is adhered to barrel walls, barrel corners and other places with relatively large curvature, and additionally, after a solid material is just added into the material barrel, the solid material is inclined to float at the surface of the wetted slurry or attach to barrel walls. During production, the solution is that the slurry or the solid material adhered to barrel walls is artificially stripped off, otherwise the stirring time is prolonged. According to the technical scheme, a spherical slurry stirring barrel is employed, a stirring paddle rotates at the sphere center, the periphery of the spherical material barrel is uniformly provided with ultrasonic transducers which give ultrasonic waves at the same time at the same phase, so that the ultrasonic superposed amplitude at the geometric center position of the spherical material barrel is increased, and violently cavitation mixing effect is generated at the center of the slurry stirring barrel. At the same time, the ultrasonic transducers attaching to the slurry stirring barrel enable the barrel walls to generate high-frequency mechanical oscillation, and the oscillation generates violent acting force at the interface between the metal barrel walls and the slurry because of abrupt change of density and elastic modulus. The comprehensive effect is that the solid material is easily wetted, and the wetted slurry is easy to homogenize.

Description

technical field [0001] The invention relates to a slurry stirring mode, in particular to a stirring mode for positive and negative electrode slurry of a lithium ion battery. Background technique [0002] Currently, known electrode pastes for lithium ion secondary batteries are composed of electrode active materials, conductive agents, binders and solvents. The positive electrode active material is usually lithium cobaltate, lithium manganate and lithium iron phosphate, the negative electrode active material is usually graphite, the positive electrode binder and solvent are generally organic systems composed of PVDF and NMP, and the negative electrode binder and solvent are generally Aqueous system composed of SBR and water respectively. Through beating, the liquid that makes up the electrode slurry and various solid materials are mixed, dissolved, dispersed, and finally homogenized as much as possible. Slurry stirring plays an important role in lithium battery manufacturin...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the problem that the stirring intensity of the existing slurry mixing tank is not uniform enough at different positions in the tank and requires too much manual intervention, and at the same time, the solid material is easy to adhere to the tank wall after being added and is not easy to wet.

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