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A kind of refractory membrane used in lithium-sulfur battery and preparation method thereof

A lithium-sulfur battery and diaphragm technology, which is applied in the field of high-performance lithium-sulfur battery fire-resistant diaphragm and its preparation, can solve the problems of ineffective adsorption of polysulfides, inapplicability of Li-S batteries, battery short circuit, etc., and achieve good high temperature Effects of shape stability, broadened application range, and improved fire resistance

Active Publication Date: 2020-03-27
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, most of the separators used in commercial batteries are polypropylene (PP) separators. This type of separator has good ion conductivity. However, PP separators made of polymer plastics are very flammable and easily deformed at high temperatures. short circuit inside the battery
In view of the disadvantages of PP separators, the preparation of electrospun separators by adding refractory materials (such as TPP) has been reported (Sci.Adv.2017, 3, e1601978), however, since this type of separator does not contain polar functional groups , cannot effectively adsorb polysulfides, so it is not suitable for Li-S batteries

Method used

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  • A kind of refractory membrane used in lithium-sulfur battery and preparation method thereof
  • A kind of refractory membrane used in lithium-sulfur battery and preparation method thereof
  • A kind of refractory membrane used in lithium-sulfur battery and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Step 1: Dissolve 1g APP in 5mL DMF, heat and stir under the condition of ambient humidity 30%, the stirring temperature is 50°C, and obtain a homogeneous polymer solution A after stirring for 15 minutes; among them, the mass of APP in polymer solution A The percentage is 10%;

[0025] Step 2: Dissolve 1 g of PAN in 5 mL of DMF, heat and stir under the condition of an ambient humidity of 30%, the stirring temperature is 50°C, and obtain a uniform polymer solution B after stirring for 15 minutes; wherein, the mass percentage of PAN in the polymer solution B 10%;

[0026] Step 3: Mix solution A and solution B, keep the ambient humidity constant, heat and stir at 70°C for 30 minutes, and obtain a uniform polymer PAN@APP electrospinning solution; wherein, the mass ratio of APP:PAN is 1: 1;

[0027] Step 4: Use a medical injection needle to absorb 10mL of PAN@APP solution, use aluminum foil as a receiving substrate, and use an electrospinning instrument model Ucalery SS-253...

Embodiment 2

[0030] Step 1: Dissolve 3g APP in 5mL DMF, heat and stir under the condition of ambient humidity 30%, the stirring temperature is 50°C, and obtain a homogeneous polymer solution A after stirring for 15 minutes; among them, the mass of APP in polymer solution A The percentage is 30%;

[0031] Step 2: Dissolve 1g of PAN in 5mL of DMF, heat and stir under the condition of 30% ambient humidity, the stirring temperature is 50°C, and obtain a uniform polymer solution B after stirring for 15 minutes; among them, the mass of PAN in the polymer solution B The percentage is 10%;

[0032] Step 3: Mix solution A and solution B, keep the ambient humidity constant, heat and stir at 70°C for 30 minutes, and obtain a uniform polymer PAN@APP electrospinning solution; wherein, the mass ratio of APP:PAN is 3: 1;

[0033] Other steps are the same as in Example 1. This method can obtain a PAN@APP fire-resistant diaphragm with better fire resistance and more abundant functional groups.

Embodiment 3

[0035] Prepare the PAN@APP fire-resistant diaphragm according to the steps in Example 1, only adjust the diameter of the spinning nozzle in step 4 to 0.7mm, adjust the spinning temperature to 45°C, adjust the distance from the needle to the receiving substrate to 40cm, and adjust the spinning negative voltage Adjusted to 10kV, the positive spinning voltage was adjusted to 10kV, and other parameters and steps remained unchanged. The thickness of the PAN@APP fire-resistant diaphragm prepared in Example 3 is 100 μm.

[0036] figure 1 SEM image of the PAN@APP fire-resistant diaphragm prepared in Example 1 of the present invention. The nanofiber-like spatial structure can provide more transmission channels for lithium ions, and at the same time, APP can also adsorb polysulfides dissolved in the battery reaction process to improve battery stability.

[0037] figure 2It is the experimental observation diagram of the contact angle of the PAN@APP refractory membrane prepared in Exa...

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Abstract

The invention provides a fire-resistant diaphragm used in a lithium-sulfur battery and a preparation method thereof, belonging to the technical field of energy materials. The invention utilizes electrospinning technology to dissolve the refractory material ammonium polyphosphate (APP) containing nitrogen and phosphorus polar groups and the polymer material polyacrylonitrile (PAN) through dimethylformamide (DMF) Under a high voltage, a fibrous mesh-like refractory polymer separator was prepared by spinning. This separator has the functions of inhibiting the dissolution of polysulfides, flame retardancy and high temperature resistance, and finally plays a role in improving the electrochemical performance and performance of lithium-sulfur batteries. safety effect.

Description

Technical field: [0001] The invention belongs to the technical field of energy materials, and in particular relates to a fire-resistant diaphragm for a high-performance lithium-sulfur battery and a preparation method thereof. Background technique: [0002] The vigorous development of new energy vehicles has put forward higher and higher requirements for the energy density and stability of lithium-ion batteries. Traditional lithium-ion batteries have been difficult to meet people's needs. Therefore, the development of high-performance lithium-ion batteries is the key to the development of new energy vehicles. necessary way. Among many new lithium batteries, the theoretical specific capacity of lithium-sulfur battery (Li-S) is as high as 1675mAh / g, and the theoretical specific energy reaches 2600Wh / kg, which is five to ten times that of traditional lithium iron phosphate batteries, and sulfur itself has no pollution. , low-cost characteristics, making Li-S battery has become ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525H01M10/42H01M50/403H01M50/414H01M50/44
CPCH01M10/0525H01M10/4235H01M50/411H01M50/44H01M50/403Y02E60/10
Inventor 熊杰吕晓雪雷天宇陈伟闫裔超胡音李政翰邬春阳
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA