Preparation method of PA/PP porous battery separator material

Abstract

The invention relates to a preparation method of a PA / PP porous battery separator material. The preparation method comprises the following steps of selecting PA / PP bi-component composite fiber and single-component synthetic fiber, and cutting the PA / PP bi-component composite fiber and the single-component synthetic fiber to short fibers for use by a disc-type fiber cutting machine; carrying out pulping and defibering processing on the cut short fibers, cellulose fiber and inorganic fiber to prepare high-concentration fiber paste; taking water as a dispersing medium and alkyl sulfonate as a dispersing agent; carrying out hydraulic single-net dual-layer inclined-net formation by a central pulp distributor; drying the product to form the porous battery separator material after dehydration and squeezing. The material has excellent performance, and can be taken as a battery separator, a capacitor separator, a high-temperature insulation film and a high-temperature filtering material after processing such as sulfonation, grafting, high-temperature pressing and coating.

Description

technical field [0001] The invention relates to the technical field of preparation of porous battery separator materials, in particular to a preparation method of PA / PP porous battery separator materials. Background technique [0002] With the rapid development of the IT electronics industry, new energy vehicles, and energy storage industries, the secondary power supply is showing a vigorous development trend. As one of the key materials of secondary power supply, the battery diaphragm plays an increasingly important role, so the manufacture of battery diaphragm materials has attracted more and more attention. [0003] At present, the preparation methods of secondary battery separator materials mainly include phase inversion method, dissolution method, stretching method, fiber dry carding, fiber wet papermaking molding, etc., among which phase inversion method, dissolution method and stretching method are mainly used to prepare lithium ion Battery diaphragm, this type of ba...

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Problems solved by technology

[0003] At present, the preparation methods of secondary battery separator materials mainly include phase inversion method, dissolution method, stretching method, fiber dry carding, fiber wet papermaking molding, etc., among which phase inversion method, dissolution method and stretching method are mainly used to prepare lithium ion Battery diaphragm, this type of battery diaphragm has a two-dimensional structure, poor temperature resistance, large thermal shrinkage, poor safety, low porosity, poor electrolyte permeability and other defects, which have their own defects in ensuring the safety and service life of lithium-ion batteries

Dry carding molding is mainly used to prepare alkaline secondary battery separators. This type of battery separator has poor fiber dispersion and uneven distribution, which cannot meet the requirements of power type, high capacity, and high rate alkaline batteries, and may easily cause poor battery consistency. , high short circuit rate and other issues

Wet papermaking technology is used to produce porous battery diaphragm materials. The diaphragm materials produced by this method can meet the application requirements of alkaline batteries, lithium-ion batteries, super capacitors, high-temperature insulating electronic components and high-temperature filtration, but due to material selection and other issues , although wet papermaking technology is currently used to produce porous battery separator materials, most of them use single-net single-layer forming, and then multi-layer compounding, or double-net double-layer forming, which will cause many problems such as equipment investment and comprehensive production costs.