Method for preparing ceramic membrane on surface of PE membrane by employing vacuum magnetron sputtering technology

Abstract

The invention discloses a method for preparing ceramic membrane on a surface of PE membrane by employing a vacuum magnetron sputtering technology. The method comprises the steps of cutting to-be-processed PE membrane into a required size in a purification room, and mounting the PE membrane on an unwinding roller of a device; starting the roll-roll vacuum magnetron sputtering coating device, and adjusting the device to a technological condition capable of coating; starting an ion source to bombard the PE membrane, and opening hydrocarbon accumulation macromolecule bonds; moreover, starting an intermediate frequency sputtering cathode, sputtering an Si target by utilization of intermediate frequency sputtering cathode reaction, thereby forming an SixNy-ceramic material, embedding the material into the locations of the opened hydrocarbon accumulation molecule bonds, thereby forming the ceramic membrane; carrying out annealing in a vacuum state, thereby eliminating the stress of the ceramic membrane; carrying out winding-unwinding continuous sputtering; finishing whole roll coating; breaking vacuum; taking a winding roller down; carrying out sampling and performance detection; and packaging the product and putting the product in storage. According to the method, a layer of ceramic membrane is deposited on the surface of the PE membrane for a lithium battery by employing the vacuum magnetron sputtering coating technology, the wettability of the PE membrane for electrolyte is improved, and the thermostability of the PE membrane is improved.

Description

technical field [0001] The invention relates to the technical field of manufacturing lithium battery devices and lithium battery materials, in particular to a method for preparing a ceramic film on the surface of a PE isolation film for a lithium battery using a vacuum magnetron sputtering technology. Background technique [0002] Because polyolefin materials have excellent properties such as high strength, water resistance and solvent corrosion resistance, and are low in price and simple in production process, they are ideal materials for lithium-ion battery separators. So far, the diaphragms that have been used in large quantities in the industry include polyethylene (PE) diaphragms, polypropylene (PP) diaphragms, and the like. [0003] Although polyolefin materials have many excellent properties, there are still many deficiencies as separator materials for lithium-ion batteries. For example, due to the high crystallinity and low polarity of the polyolefin polymer, the af...

AI Technical Summary

Problems solved by technology

Lithium battery cell manufacturers also found that when using PE separators coated with ceramic coatings, although the ceramic coatings improved the fusing temperature and thermal shrinkage of the separators, the through-porosity of the PE separators coated with ceramic coatings decreased. 10%, and the ceramic coating is easy to dissolve and delaminate when it encounters the electrolyte, thereby increasing the internal resistance of the battery. This is mainly because the thickness of the wet-coated ceramic coating is difficult to control, and the thinnest is only It can reach 3um, the greater the thickness of the coating, the more serious the impact on the through-porosity of the diaphragm; the wet coating is to use the adhesive to bond the ceramic layer to the diaphragm through mechanical extrusion, and the bonding force of the two materials is poor, so prone to dissolution and delamination