Device and method for removing magnetic foreign matter in lithium battery material

Abstract

The invention discloses a device and a method for removing a magnetic foreign matter in a lithium battery material. The device comprises a shell, a demagnetizing cavity, a plurality of cylinders and magnetic bars, wherein the demagnetizing cavity is formed by magnetic plates; the plurality of cylinders are arranged in the demagnetizing cavity; each magnetic bar is inserted into each cylinder; and a liquid inlet and a liquid outlet are formed in the top part and the bottom part of the demagnetizing cavity respectively. According to the method disclosed by the invention, the magnetic foreign matter in a liquid material or slurry is absorbed when entering from the liquid inlet of the device for removing the magnetic foreign matter and passing through the magnetic bars and the magnetic plates, does not enter the next procedure; and if the content of the magnetic foreign matter does not reach the index requirements, the magnetic foreign matter can be removed in cycle. According to the device and the method, the content of the magnetic foreign matter in the liquid material or slurry can be efficiently lowered.

Description

technical field [0001] The invention relates to the field of lithium battery preparation, in particular to a device and method for removing magnetic foreign matter in lithium ion battery materials. Background technique [0002] The existence of magnetic foreign matter has brought great hidden dangers to the safety performance of lithium-ion batteries. The product quality of lithium-ion battery materials, especially the control of magnetic foreign matter, is the key to solving the safety problem of lithium-ion batteries. At present, lithium-ion battery materials have very high requirements for magnetic foreign matter. Domestic battery manufacturers generally require about 100 ppb for the content of magnetic foreign matter in the positive electrode material of lithium batteries. High-end battery manufacturers generally require 50 ppb for the content of magnetic foreign matter in the positive electrode material of lithium-ion batteries. Around the world, foreign power battery c...

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Problems solved by technology

The existing demagnetization equipment is mainly electromagnetic demagnetization equipment. The principle is to absorb the magnetic foreign matter in the powder material or liquid by exciting the magnetic body, and then demagnetize the magnetic body to remove the magnetic foreign matter from the magnetic body. Flush on the top to discharge magnetic foreign matter, and the material of the magnetic body is mainly stainless steel. In the process of processing materials, as the properties of the material change, long-term use may cause corrosion to the material of the equipment, and it is difficult to guarantee the effect of removing magnetic foreign matter on the material. ;Secondly, the electromagnetic demagnetization equipment generates a lot of heat and consumes a lot of energy during the working process, and the selection of the type is limited due to the characteristics of some materials; finally, most powder materials use strong magnetic equipment to reduce the content of magnetic foreign matter. At present, the content of magnetic foreign matter Generally, it is best to control it at about 50ppb, and the direct yield of the product will not be very high by removing magnetic foreign matter by dry method

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