Waterborne slurry used for coating lithium ion battery diaphragm and preparation method for waterborne slurry

Abstract

The invention provides waterborne slurry used for coating a lithium ion battery diaphragm and a preparation method for the waterborne slurry. The waterborne slurry is prepared from the components of 20-35 parts of inorganic ceramic powder, 0.2-3 parts of dispersing agent, 2-10 parts of binder, 20-50 parts of adhesive dispersion liquid, 0.3-2 parts of surfactant, 0.1-2 parts of anti-settling agent and 30-60 parts of deionized water. The preparation method comprises the steps of adding the inorganic ceramic powder, the dispersing agent, the anti-settling agent and the deionized water into a dispersing machine based on proportion to be subjected to high-speed dispersion for 1-3h, and then adding the binder, the adhesive dispersion liquid and the surfactant to be subjected to low-speed dispersion for 0.5-2h and then enabling the obtained mixture to be sieved by a 200-mesh screen to obtain slurry; and finally uniformly coating the surface of a base diaphragm of the diaphragm with the slurry by using a coating machine, and drying the diaphragm. The waterborne slurry can be manufactured favorably, and also has the dual advantages of reduction of thermal shrinkage by virtue of the ceramic diaphragm, improvement of electrolyte wettability, and improvement of lithium ion battery interface and cycling performance due to the gummed diaphragm, and the like.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a new material for lithium-ion battery separators and a preparation method thereof. Background technique [0002] In lithium batteries, the main function of the separator is to keep the positive and negative electrodes separated to prevent short circuits, while allowing the rapid transfer of ions, which is a more important component in lithium-ion batteries. The performance of the separator will directly affect the characteristics of the battery, such as the capacity, internal resistance, rate, cycle and self-discharge of the battery. At present, the material of lithium-ion battery diaphragm is usually polyolefin material, which has poor heat resistance. When the battery temperature reaches the fusing temperature of the diaphragm, the diaphragm will be fused, and the positive and negative electrodes will directly contact, resulting in an internal short c...

AI Technical Summary

Problems solved by technology

At present, the material of lithium-ion battery diaphragm is usually polyolefin material, which has poor heat resistance. When the battery temperature reaches the fusing temperature of the diaphragm, the diaphragm will be fused, and the positive and negative electrodes will directly contact and produce an internal short circuit.

Although there is a multi-layer composite diaphragm with higher safety, it still cannot meet the safety requirements of the power battery for the diaphragm

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