Battery diaphragm, preparation method thereof and battery comprising battery diaphragm

A battery separator and electrolyte technology, applied in secondary batteries, battery pack parts, circuits, etc., can solve the problems of low electrical conductivity and easy breakage, and achieve the effects of improving elongation at break, low cost, and high ionic conductivity

Active Publication Date: 2019-12-20
SUZHOU QINGTAO NEW ENERGY TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the battery separator used is polyethylene film, polypropylene film or a composit

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] This embodiment provides a battery separator, including a first polymer electrolyte layer, a ceramic layer and a second polymer electrolyte layer stacked in sequence;

[0055] Among them, the materials of the first polymer electrolyte layer and the second polymer electrolyte layer are the same, including the following components in weight percentage: polymer (PVDF) 87%, ceramic powder (alumina) 2%, lithium salt (LiTFSI) 1 % and plasticizer (PC) 10%.

[0056] The preparation method of the above-mentioned battery diaphragm is as follows:

[0057] (1) Add PVDF, alumina (Weifang Zhongkai New Material Co., Ltd., particle size D50=500nm), LiTFSI and PC into DMF according to the mass ratio of 87:2:1:10, mix well to obtain polymer electrolyte slurry material;

[0058] (2) Coat the slurry obtained in step (1) on the copper foil substrate, and bake at 70°C for 20 minutes to form the first polymer electrolyte layer (thickness 4 μm);

[0059] (3) Cover the PE separator coated wi...

Embodiment 2

[0063] This embodiment provides a battery separator, including a first polymer electrolyte layer, a ceramic layer and a second polymer electrolyte layer stacked in sequence;

[0064] Wherein, the materials of the first polymer electrolyte layer and the second polymer electrolyte layer are the same, including the following components by weight percentage: polymer (PEC) 10%, ceramic powder (LLZTO) 30%, lithium salt (LiFSI) 30% , plasticizer (DMC) 15% and plasticizer (EC) 15%.

[0065] The preparation method of the above-mentioned battery diaphragm is as follows:

[0066] (1) Add PEC, LLZTO (Qingyuan New Material Technology Co., Ltd., particle size D50=500nm), LiFSI, DMC and EC in NMP according to the mass ratio of 10:30:30:15:15, mix well, and obtain polymerization Electrolyte slurry;

[0067] (2) Coat the slurry obtained in step (1) on an aluminum foil substrate, and bake at 110° C. for 1 min to form a first polymer electrolyte layer (thickness 6 μm);

[0068] (3) Cover the ...

Embodiment 3

[0072] This embodiment provides a battery separator, including a first polymer electrolyte layer, a ceramic layer and a second polymer electrolyte layer stacked in sequence;

[0073] Wherein, the materials of the first polymer electrolyte layer and the second polymer electrolyte layer are the same, including the following components by weight percentage: polymer (PVDF-HFP) 50%, ceramic powder (LLZO) 5%, ceramic powder (SiO 2 )5%, lithium salt (LiBF 4 ) 10% and plasticizer (DEC) 30%.

[0074] The preparation method of the above-mentioned battery diaphragm is as follows:

[0075] (1) Add PVDF-HFP, LLZO (Qingyuan New Material Technology Co., Ltd., particle size D50=500nm) and SiO in DMAc according to the mass ratio of 50:5:5:10:30 2 (Nanjing Haitai Nano Materials Co., Ltd., particle size D50=60nm), LiBF 4 and DEC, mixed evenly to obtain a polymer electrolyte slurry;

[0076] (2) Coating the slurry obtained in step (1) on the PET substrate, and baking at 50°C for 50min to form...

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Abstract

The invention provides a battery diaphragm, a preparation method thereof and a battery comprising the battery diaphragm. The battery diaphragm comprises a ceramic layer, and a first polymer electrolyte layer and a second polymer electrolyte layer which are arranged on two sides of the ceramic layer, wherein the first polymer electrolyte layer and the second polymer electrolyte layer respectively and independently comprise components in percentage by weight, 10-87% of polymer, 2-30% of ceramic powder, 1-30% of lithium salt and 10-30% of plasticizer. The battery diaphragm is prepared by dispersing materials of the first polymer electrolyte layer and the second polymer electrolyte layer in solvent to prepare the slurry, and then forming a film with the ceramic layer in sequence. The battery diaphragm is advantaged in that the battery diaphragm has a relatively high liquid absorption rate, ionic conductivity and elongation at break, can effectively reduce the risk of diaphragm rupture, andimproves the rate capability and cycle performance of the battery.

Description

technical field [0001] The invention belongs to the field of battery technology, and in particular relates to a battery diaphragm, a preparation method thereof and a battery comprising the same. Background technique [0002] Lithium-ion batteries have been recognized by the market due to their advantages such as large specific energy, high specific power, small self-discharge, no memory effect, good cycle performance, fast discharge and high efficiency, and no environmental pollution. Tools, energy storage and new energy vehicles have a wide range of applications. [0003] However, with the occurrence of lithium battery safety accidents, its safety has attracted increasing attention. The separator can effectively prevent the short circuit between the positive and negative electrodes, and is an important part that affects the safety of lithium batteries. Most of the current commercial separators use polyolefin separators or ceramic-coated polyolefin separators, such as PP (...

Claims

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Application Information

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IPC IPC(8): H01M2/16H01M2/14H01M10/0525
CPCH01M10/0525H01M50/403H01M50/431H01M50/446H01M50/449Y02E60/10
Inventor 李峥冯玉川何泓材刘京亮杨帆南策文
Owner SUZHOU QINGTAO NEW ENERGY TECH CO LTD
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