A kind of melt-blown polyphenylene sulfide non-woven lithium battery diaphragm and preparation method thereof

Abstract

The invention relates to a lithium battery diaphragm of melt-blown polyphenylene sulfide non-woven fabric and a preparation method thereof. Including the drying of polyphenylene sulfide pellets in the preparation process of melt-blown polyphenylene sulfide non-woven fabrics, melt extrusion, hot air drafting, cooling, and coagulation. The process conditions of treatment and heat setting treatment were optimized to prepare melt-blown polyphenylene sulfide non-woven lithium battery separator. The melt-blown polyphenylene sulfide nonwoven lithium battery separator prepared by the present invention has the advantages of high melting point, high membrane rupture temperature, good flame retardancy, thinner thickness, smooth surface, good chemical and dimensional stability, and the lithium The battery separator has good liquid absorption, small pore size and high porosity, which meets the requirements of the lithium battery separator, improves the safety of the lithium battery and prolongs its service life.

Description

technical field [0001] The invention relates to a preparation method of a lithium battery diaphragm, in particular to a melt-blown polyphenylene sulfide nonwoven lithium battery diaphragm and a preparation method thereof. Background technique [0002] Lithium batteries have developed rapidly in recent years because of their advantages such as high specific energy, long cycle life, and no memory effect, but the safety of lithium batteries has always been a key issue restricting their development. The separator is a key component of lithium battery safety. The separator is an electrically insulating film with a porous structure. Its main function is to isolate the positive and negative electrodes and prevent the electrons in the battery from freely passing through, while allowing ions (in the electrolyte) to pass freely between the positive and negative electrodes. Its performance determines the interface structure and internal resistance of the battery, which directly affect...

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Problems solved by technology

However, the process of this method is cumbersome, and most of the organic solvents used are toxic solvents, which are not environmentally friendly.

Chinese Patent No. CN101736418A, published on June 16, 2010, the name of the invention patent is "a method for manufacturing polyphenylene sulfide melt-blown fiber products". The polyphenylene sulfide resin melt-blown fiber material between 1.8 and 19 is used as the raw material. After high-speed mixing and mixing, the twin-screw extruder melts, granulates, slices and melts, and extrudes and spins to obtain polyphenylene sulfide melt-blown short fibers. Fiber, and rapidly cooled with nitrogen, the polyphenylene sulfide short fiber obtained by this method has good toughness, but, for the application development of polyphenylene sulfide melt-blown fiber for lithium battery diaphragm products, the patent does not involve specific process parameters and technical solutions

Chinese Patent No. CN103961939A, published on August 6, 2014, the patent name of the invention is "a preparation method of polyphenylene sulfide composite filter material". The short fiber web is compounded by the array embedding method, and then the composite filter material is heat-set by the temperature programming process to obtain a polyphenylene sulfide composite filter material. This method heat-sets the polyphenylene sulfide composite fiber web , to obtain a composite filter material with a high filtration rate, but for the hot rolling and heat setting treatment of the single-layer melt-blown polyphenylene sulfide fiber web, the patent does not involve specific process parameters and technical solutions

The PP material or PE material has a low melting point, resulting in a very low rupture temperature of the diaphragm, and its own poor flame retardancy, resulting in low safety of lithium batteries.