A method for manufacturing a power lithium-ion battery separator by a wet papermaking process

Abstract

The invention relates to a method for manufacturing a power lithium-ion battery diaphragm by a wet papermaking process. The method comprises the preparation of PE-Copet sea-island short fibers, the preparation of hollow PP short fibers, and the preparation of surface layer non-woven fabrics from PE-Copet sea-island short fibers, consisting of 70-80wt% PP short fibers and 30-20wt% PE-Copet short fibers are used to prepare the middle layer of composite non-woven fabrics, and then bonded by hot rollers, at a temperature of 120-135°C and a pressure of 3-7 MPa to form a PE / PP / PP with a thickness of 20-35µm PE three-layer composite non-woven fabric film. Then the PE / PP / PE three-layer composite non-woven fabric membrane is put into the alkali subtraction method to dissolve and precipitate the Copet in the island to form pores with a pore size of 0.25-0.5µm. After washing, it is dried and shaped to obtain a power lithium-ion battery separator. . In the present invention, the middle PP layer is a high-strength hollow FDY wire, which forms a skeleton layer and a porosity layer. When the PE is closed at high temperature in the lithium battery, the skeleton layer keeps the diaphragm dimensionally stable and prevents lithium ion short circuit from causing explosion.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery diaphragms, and in particular relates to a method for manufacturing power lithium-ion battery diaphragms through a wet papermaking process. Background technique [0002] The separator is a key material in the structure of the power lithium battery, and its performance must have high porosity, good strength, uniform and controllable pore size within a certain area. Thermal dimensional stability, thermal shutdown temperature and thermal melting temperature wettability and other properties. At present, the production of lithium-ion separators usually adopts two methods: dry method and wet method; the performance of the separator produced by the dry method is low, which cannot meet the needs of high-power power lithium batteries. Therefore, people are constantly developing the polyolefin non-woven lithium battery separator produced by the wet papermaking process. High strength, high poro...

AI Technical Summary

Problems solved by technology

At present, the production of lithium-ion separators usually adopts two methods: dry method and wet method; the performance of the separator produced by the dry method is low, which cannot meet the needs of high-power lithium-ion batteries.