Porous film and preparation method thereof, and lithium battery

A technology of porous membrane and para-aramid fiber, which is applied in the field of porous membrane, can solve the problems that the content of coating binder cannot be too high, affect the thermal stability of the coated separator, and cannot match the aramid fiber, etc. The effect of good support and good safety

Active Publication Date: 2019-10-29
微宏先进膜公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to ensure that the coating has a certain lithium ion passing rate, the content of the coating binder should not be too high. Due to the poor thermal stability of the existing binder, it will decompose at a higher temperature, resulting in the separation of the separator at a higher temperature. The coating becomes loose which affects the thermal stability of the coated separator
Therefore, the existing binder cannot match the aramid fiber, and cannot fully exert its true function

Method used

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  • Porous film and preparation method thereof, and lithium battery
  • Porous film and preparation method thereof, and lithium battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0088] 100g poly-p-phenylene terephthalamide pulp, 15.0g sodium hydroxide and 500g DMSO are mixed, react 4h at 50 ℃, form poly-p-phenylene terephthalamide nanofiber solution (fiber diameter is 400nm with a length of 2μm). Add 20.0 g of NaH to the poly-p-phenylene terephthalamide nanofiber solution, stir at 70° C. for 1 h to completely react the two, and obtain solution A. With 10g ethylene dichloride and 83g meta-aramid slurry (wherein the meta-aramid slurry is made of meta-aramid, the solvent is DMAC and the cosolvent is CaCl 2 Mix to obtain, the quality of meta-aramid fiber is 25g), join in the above-mentioned solution A, react at 70 ℃ for 2h to form coating slurry, the coating slurry is coated on PE base film (the thickness of base film is 16 μm, porosity 54%) surface film formation; Described film passes through coagulation bath, obtains described porous film; Described coagulation bath is DMAC and H 2 O, wherein the mass ratio of DMAC to water is 3:7, the temperature of...

Embodiment 2

[0093] With embodiment 1, difference is that 10g dichloroethane, 83g meta-aramid slurry (wherein meta-aramid slurry is made of meta-aramid, solvent is DMAC and auxiliary solvent is CaCl 2 Mix and obtain, the quality of meta-aramid fiber is 25g) and 12.5g SiO 2 (particle size of 30nm) was added to the above A solution. A porous film was obtained; the air permeability of the porous film was 206s / 100mL; the porous film was treated at 150°C for 30 minutes, and its longitudinal shrinkage rate was 0.3%, and its transverse shrinkage rate was 0.3%; the battery production and performance test were the same as in Example 1; Battery test results: After 1899 cycles, the capacity retention rate is 86.5%.

Embodiment 3

[0095] 100g poly-p-phenylene terephthalamide pulp, 15.0g sodium hydroxide and 500g DMSO are mixed, react 4h at 50 ℃, form poly-p-phenylene terephthalamide nanofiber solution (fiber diameter is 400nm with a length of 2μm). Add 33.3g KH into the poly-p-phenylene terephthalamide nanofiber solution, stir at 70°C for 1 hour, and make the two completely react to obtain solution A. With 1.0g ethylene dichloride and 220g meta-aramid slurry (wherein the meta-aramid slurry is made of meta-aramid, the solvent is DMAC and the cosolvent is CaCl 2 Mix to obtain, the quality of meta-aramid fiber is 11g), join in the above-mentioned solution A, react at 70 ℃ for 2h to form coating slurry, the coating slurry is coated on PE base film (the thickness of base film is 16 μm, porosity 54%) surface film formation; Described film passes through coagulation bath, obtains described porous film; Described coagulation bath is DMAC and H 2 O, wherein the mass ratio of DMAC to water is 3:7, the temperatu...

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Abstract

The invention provides a porous film. The porous film includes a base material and a coating layer, and raw materials of the coating layer include para-aramid, meta-aramid, and polyhalogenated compounds. The porous film obtained by the invention is provided with good air permeability, high temperature resistance and lithium ion conductivity, and the lithium battery obtained by using the porous film of the invention has good safety, cycle life and rate performance.

Description

technical field [0001] The invention relates to a porous film, its preparation method and lithium battery. Background technique [0002] With the gradual popularization of electric vehicles, lithium-ion batteries as a power source are also developing in the direction of high energy density, high capacity and high safety, which puts forward higher requirements for electrode materials and separators in lithium-ion batteries. [0003] In lithium-ion batteries, the separator plays a very important role in the entire battery system as a component that isolates the positive and negative electrodes. First of all, the separator itself must be light and thin and maintain good strength, occupying little space in the battery, which is conducive to the battery having a high energy density, and can prevent particles on the positive or negative electrode from passing through the separator to cause a short circuit of the battery, especially It is to prevent short circuit caused by lithium...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M2/14H01M10/052
CPCH01M10/052H01M50/403H01M50/411H01M50/44H01M50/449Y02E60/10
Inventor 罗建海孙庆津何庆一
Owner 微宏先进膜公司
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