Production technology for novel high-porosity lithium ion battery membrane

Abstract

The invention provides a production technology for a novel high-porosity lithium ion battery membrane, which belongs to the field of battery membranes, and solves the problem that the porosity of the conventional membrane in the market is low. Due to the adoption of the high-porosity membrane obtained by the production technology disclosed by the invention, the performance of a lithium ion battery can be obviously improved. The production technology comprises the steps of feeding polyethylene and white oil mixture into a double-screw extruder to obtain an oil-containing cast sheet through a metering, filtering and extruding die head and a cooling device; then putting the oil-containing cast sheet into an extraction tank, and extracting white oil in the cast sheet; volatilizing to remove a dichloromethane extracting agent on the surface and in the extracted cast sheet to obtain a dry cast sheet; performing bidirectional stretching on the dry cast sheet to obtain the membrane; finally coiling the membrane subjected to the bidirectional stretching after the membrane is subjected to thermal sizing treatment to obtain a finished membrane product. According to the membrane preparation technology, the cast sheet is extracted, then is subjected bidirectional stretching and is subjected to thermal sizing to obtain the lithium battery membrane with the porosity being over 60 percent.

Description

technical field [0001] The invention belongs to the field of battery diaphragms, and in particular relates to a production process of a novel high-porosity lithium-ion battery diaphragm. Background technique [0002] As a high-energy power source, lithium-ion batteries have been widely used in fields such as portable electronic devices, electric tools, electric vehicles, and energy storage power stations. The separator is one of the important raw materials for batteries. Therefore, the safety of lithium-ion batteries Sexuality has always been a concern. As an important part of the lithium-ion battery, the diaphragm is used to separate the positive electrode from the negative electrode material, allowing ions to pass through and preventing electrons from passing through. The performance of the lithium battery diaphragm determines the interface structure and internal resistance of the battery, which directly affects the capacity of the battery. , cycle and safety performance,...

AI Technical Summary

Problems solved by technology

[0003] In order to improve the high temperature resistance of lithium battery separators, nano-ceramic coated separators have gradually become the focus of development, but the increase of ceramic coatings will reduce the porosity of the separators, and the reduction of porosity will directly lead to the performance of lithium batteries. , the purpose of the present invention is to prepare a high-porosity raw material diaphragm for the coating process

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