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

Abstract

The invention relates to a method for manufacturing a separator of a power lithium ion battery by a wet papermaking process. The method comprises the preparation of PE-Copet island-type staple fiber,preparation of hollow PP staple fiber, preparation of surface layer non-woven fabric from PE-Copet island-type staple fiber, the intermediate layer composite non-woven fabric is prepared from 70-80 wt% of PP staple fiber and 30-20 wt% by PE-Copet staple fiber, and then hot-pressed by hot roll, the temperature is 120-135 DEG C, and the pressure is 3-7 MPa to form PE / PP / with thickness of 20-35 [mu]m PE three-layer composite non-woven film. Then the PE / PP / PE three-layer composite non-woven membrane adopts the alkali reduction method to dissolve the Copet in the island to form a pore with a porediameter of 0.25-0.5[mu]m. After ishing, the material subjected to drying and setting treatment to obtain power lithium ion battery separator. In the present invention, the intermediate PP layer is ahigh-strength hollow FDY wire, forming a skeleton layer and a porosity layer. When the PE is closed at a high temperature of the lithium battery, the skeleton layer keeps the size of the separator stable and prevents the lithium ion short circuit from causing an 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.