Lithium battery diaphragm with toughened modified polyvinylidene fluoride matrix and preparation method thereof

A polyvinylidene fluoride, lithium battery separator technology, applied in battery pack parts, circuits, electrical components, etc., can solve the problems of low liquid absorption rate and hard texture, and achieve the effect of cost reduction

Active Publication Date: 2019-01-01
HAIAN INST OF HIGH TECH RES NANJING UNIV +2
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of hard texture and low liquid absorption rate in the process of using PVDF as a lithium battery diaphragm, the present invention uses acrylate rubber with excellent heat resistance and solvent resistance as a flexible segment to modify PVDF, thereby reducing the PVDF Brittleness, improve the liquid absorption rate of PVDF, after the acrylate is vulcanized at high temperature in the later stage, the solvent resistance and strength of the film will be further improved

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Embodiment 1: (the proportions are all mass ratios).

[0028] Step 1: Mix PVP:DMAc:PVDF=3:40:20 and dissolve slowly at 25°C to prepare polyvinylidene fluoride polyvinylidene fluoride solution (solution 1).

[0029] Step 2: Mix difluoropropane: azobisisobutyronitrile: acrylate rubber (glass transition temperature -15°C, Mooney viscosity 30) = 10:1:0.05, dissolve slowly at 30°C to prepare acrylate rubber solution (Solution 2).

[0030] Step 3: Solution 1: Solution 2 = 1:1, slowly add solution 2 to solution 1, stir slowly at a speed of 30r / min, mix the two and continue stirring for 3h until the solution is clear and free of particles or flocs .

[0031] Step 4: Disperse the fumed silica in the water-ethanol mixed solvent, slowly add KH-550 dropwise, where fumed silica: water: ethanol: KH-550=10:30:20:0.5, at 50-70 °C for constant temperature hydrolysis and modification for 3 hours, the mixed solvent was distilled off by vacuum distillation, and the prepared modified sil...

Embodiment 2

[0035] Embodiment 2: (the proportions are all mass ratios).

[0036] Step 1: Mix PVP:DMAc:PVDF=4:50:20 and slowly dissolve at 35°C to prepare a polyvinylidene fluoride solution (solution 1).

[0037] Step 2: Mix difluoropropane: azobisisobutyronitrile: acrylate rubber (glass transition temperature -25°C, Mooney viscosity 40) = 15:2:0.08, dissolve slowly at 35°C to prepare acrylate rubber solution (Solution 2).

[0038] Step 3: Solution 1: Solution 2=2:1.5, slowly add solution 2 to solution 1, stir slowly at a speed of 30r / min, mix the two and continue stirring for 3h until the solution is clear without particles or flocs .

[0039] Step 4: Disperse the fumed silica in the water-ethanol mixed solvent, slowly add KH-550 dropwise, where fumed silica: water: ethanol: KH-550=10:30:20:0.5, at 50-70 °C for constant temperature hydrolysis and modification for 3 hours, the mixed solvent was distilled off by vacuum distillation, and the prepared modified silica was pulverized into na...

Embodiment 3

[0043] Embodiment 3: (the proportions are all mass ratios).

[0044] Step 1: Mix PVP:DMAc:PVDF=4:50:30 and slowly dissolve at 35°C to prepare a polyvinylidene fluoride solution (solution 1).

[0045] Step 2: Mix trifluoropropane: benzoyl peroxide: acrylate rubber (glass transition temperature -30°C, Mooney viscosity 30) = 15:3:0.2, slowly dissolve at 30°C to prepare acrylate rubber solution (solution 2).

[0046] Step 3: Solution 1: Solution 2 = 2:1, slowly add solution 2 to solution 1, stir slowly at a speed of 30r / min, mix the two and continue stirring for 4h until the solution is clear and free of particles or flocs .

[0047] Step 4: Disperse the fumed silica in the water-ethanol mixed solvent, slowly add KH-550 dropwise, where fumed silica: water: ethanol: KH-550=10:30:20:0.5, at 50-70 °C for constant temperature hydrolysis and modification for 3 hours, the mixed solvent was distilled off by vacuum distillation, and the prepared modified silica was pulverized into nano...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
glass transition temperatureaaaaaaaaaa
heat deflection temperatureaaaaaaaaaa
heat deflection temperatureaaaaaaaaaa
Login to view more

Abstract

The invention discloses a toughened and modified polyvinylidene fluoride-based lithium-ion battery separator and a preparation method thereof. The preparation method comprises the following steps: 1) polyvinylidene fluoride (PVDF)-acrylate rubber (ACM ) Preparation of solution, 2) Preparation of modified nano-silica, 3) Preparation of polyvinylidene fluoride-modified nano-silica hybrid solution, 4) Film spraying, drying to form a film, 5) Film hot pressing deal with. The present invention uses acrylic rubber (ACM) to modify polyvinylidene fluoride (PVDF) to improve its toughness, thereby reducing the breakage rate in production and increasing the service life; at the same time, the surface energy of PVDF film is improved, so that the lithium battery electrolyte can be better Wetting film, improve battery performance.

Description

technical field [0001] The invention relates to the technical field of preparation of porous membrane materials, in particular to a lithium battery diaphragm and a preparation method thereof. Background technique [0002] PVDF film has good chemical stability, its heat distortion temperature is 112~145℃, and its long-term service temperature is -40~150℃, which is much higher than the normal use environment of batteries; It is corroded by halogens, and organic solvents such as aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, and aldehydes have no effect on it. Only a few chemicals such as oleum, strong alkali, ketones, and ethers can make it swell or partially dissolve. Compared with the traditional polyolefin lithium battery separator, PVDF film has more excellent heat resistance, deformation resistance and service life as a lithium battery separator. [0003] However, the PVDF film has a relatively hard texture, which is prone to film cracking during the production...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/14H01M2/16H01M50/403H01M50/411H01M50/417
CPCH01M50/403H01M50/446H01M50/411H01M50/449Y02E60/10
Inventor 陆洪彬孟祥康张秋香朱强高扬之吴培龙陈建国
Owner HAIAN INST OF HIGH TECH RES NANJING UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap