Preparation method for inorganic / organic multilayer composite separator

Abstract

The invention discloses a preparation method for an inorganic / organic multilayer composite separator. The method comprises: soaking a separator in an organic solvent, cleaning surface of the separator by using ultrasonic vibration for 15 ~ 30min, drying in an oven, and then cutting the separator into a square separator; placing the above square separator and a target material into a RF (radio frequency) sputtering device; adjusting the air pressure of the RF sputtering device to be 0.1 ~ 1.0Pa, and then feeding in reactant gas, the sputtering power being 5 ~ 80W and the sputtering time being 5 ~ 100min; running the device, so target material plasma bombards gas molecules to form inorganic matter / organic matter which deposit on both sides of the separator to obtain an inorganic / organic multilayer composite separator. By uniformly sputtering one layer or a plurality of layers of inorganic matter / organic matter on the porous separator surface, the dimensional stability of ordinary separators is effectively improved, and the heat resistance of the separator is improved.

Description

technical field [0001] The invention belongs to the technical field of high-performance diaphragm preparation, and in particular relates to a preparation method of an inorganic / organic multilayer composite diaphragm. Background technique [0002] As an important part of lithium-ion batteries, separators have attracted extensive attention from researchers. The high performance of lithium-ion batteries is closely related to the properties of separators. Especially in lithium batteries with high rate and fast charge and discharge, the performance requirements of separators are more obvious. In view of the fact that the separator has a crucial impact on the performance of the actual battery, it must have good chemical and electrochemical stability and maintain a high degree of wettability to the electrolyte during repeated charge and discharge. The interface between the separator material and the electrode The compatibility and the retention of the electrolyte by the separator h...

AI Technical Summary

Problems solved by technology

Some researchers consider using the method of ion sputtering to prepare multilayer composite films, such as patent CN 102427119A, CN 102709592A mentioned that the method of ion sputtering is used to plate an inorganic layer on the surface of the diaphragm, which can improve heat resistance and effectively control the thickness , but the coating is limited by the target material, especially the high-purity target material of nitride and oxide is expensive, difficult to prepare, and has great restrictions on the functionalization of the diaphragm, so it is difficult to popularize and use

[0005] At present, the thickness of the widely used coating method is difficult to control, and there are problems of uneven powder dispersion, agglomeration, and agglomeration in the slurry. At the same time, the storage of the slurry Poor stability, after standing for a period of time, there will be obvious precipitation and difficulty in secondary dispersion

Although the newly proposed ion sputtering method can effectively control the thickness, it is limited by the target material, especially the difficulty in the preparation of special targets, which hinders the preparation of high-performance diaphragms with controllable thickness.

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