Preparation method of porous imino polymer in-situ coated sulfenyl polymer positive electrode material

Abstract

The invention discloses a preparation method of a porous imino polymer in-situ coated sulfenyl polymer positive electrode material, and relates to the technical field of chemical power sources. The method specifically comprises the following steps: dispersing an aldehyde group structure-containing compound, an amino structure-containing compound and a sulfenyl polymer positive electrode material in an organic solvent to prepare a mixed solution; and adding acid into the prepared mixed solution to initiate polymerization of the aldehyde group and the amino group so as to form the porous imine polymerized and coated sulfenyl polymer positive electrode material. The electrochemical performance of the sulfur-based polymer positive electrode material is improved, and the transmission efficiency of electrolyte and lithium ions is improved; the porous imino polymer film formed on the surface of the positive electrode material not only has elasticity, but also can effectively restrain the volume expansion problem of the positive electrode in the charging and discharging process, so that the service life of the battery is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of chemical power sources, in particular to a method for preparing a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material. Background Art

[0002] In the past few decades, porous imine polymers have attracted extensive attention in many fields of science and technology as a new class of two-dimensional (2D) or three-dimensional crystalline polymers with multifunctional properties, originating from the presence of a small number of uniform pores at the nanometer scale. In particular, 2D porous imine polymers are considered to be a source of diverse and stable new layered materials because they consist of atomically thin layers covalently bonded in the lateral direction, which can be bound together in the vertical direction through out-of-plane van der Waals interactions. Due to the anisotropy of surface energy in the vertical and lateral crystallographic directions, they are also expected to be isolated or formed into individual atomically thin 2D materials, similar to other representative layered materials such as graphite (to graphene), hexagonal boron nitride, and transition metal dichalcogenides. Such 2D porous imine polymers can improve the density of redox active sites; increase or decrease the voltage platform of the positive and negative electrodes; increase the electronic conductivity to fully utilize their redox active sites; balance the density and porosity through structural optimization to effectively utilize their pores and active sites, etc.

[0003] Based on this, the present invention innovatively utilizes the optimization properties of porous imine-based polymers for ionic conductivity and covers them on the surface of sulfur-based polymer positive electrodes through in-situ coating technology. This method significantly improves the conduction efficiency of lithium ions in positive electrode materials and improves the ion diffusion capacity of materials, providing a new solution for the development of high-performance batteries. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material, comprising the following steps:

[0006] S1, taking an aldehyde-containing structural compound, an amino-containing structural compound and a sulfur-based polymer positive electrode material, dispersing them in an organic solvent to prepare a mixed solution;

[0007] S2, adding acid to the mixed solution prepared in step S1 to initiate polymerization of aldehyde groups and amino groups to form a porous imine-polymer-coated sulfur-based polymer positive electrode material.

[0008] Preferably, the sulfur-based polymer positive electrode material is one of sulfided polyacrylic acid, sulfided polyaniline, sulfided polyacrylonitrile, sulfided polytetravinylpyridine, sulfided 1,3-diisopropenylbenzene, sulfided poly(3-hexylthiophene-2,5-diyl), sulfided 1,3-diethynylbenzene, sulfided aminophenol-formaldehyde resin, and sulfided poly(1,2,4,5-4 amino)benzene;

[0009] The organic solvent is NMP, DMF, chloroform, tetrachloroethane, dichloromethane and ethylene glycol dimethyl ether; the acid is one of hydrochloric acid, sulfuric acid, nitric acid and acetic acid;

[0010] The molar ratio of the compound containing an aldehyde structure to the compound containing an amino structure is 1:10-10:1;

[0011] The mass ratio of the positive electrode material of the porous imine polymer and the sulfur-based polymer is (0.01-3):10.

[0012] The present invention also provides a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material.

[0013] Preferably, the positive electrode material is used to assemble a battery.

[0014] Preferably, the negative electrode of the assembled battery is lithium metal, sodium metal and potassium metal;

[0015] The diaphragms are PP, PE, PP / PE / PP / , PETE and PEO diaphragms.

[0016] Preferably, the assembled battery is used in lithium metal batteries, lithium ion batteries, sodium ion batteries, sodium metal batteries, potassium ion batteries, and potassium metal batteries.

[0017] Beneficial effects of the invention: Efficient selective ion transport: Through the unique in-situ porous coating technology of porous imine-based polymers, the invention significantly improves the transmission efficiency of electrolytes and lithium ions. This design allows lithium ions to be selectively transported through pores of specific sizes, thereby effectively confining the lithium ion flow and promoting its efficient conduction in the positive electrode sheet;

[0018] Excellent volume expansion inhibition ability: The porous imine-based polymer film formed on the surface of the positive electrode material not only has excellent elasticity, but also can effectively inhibit the volume expansion problem that may occur in the positive electrode during the charging and discharging process. This feature is crucial to improving the stability and cycle life of the battery;

[0019] Economical, recyclable and easy to mass produce: The porous imine-based polymer-coated sulfur-based polymer positive electrode material prepared by this method is not only economical and efficient, but also conforms to the concept of green production. The present invention also has the potential to be easily mass-produced, providing new possibilities for the sustainable development of the battery industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the aldehyde-containing structural compound of the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the amino-containing structure compound of the present invention.

[0022] Figure 3 It is a schematic diagram of the structure of the porous imine-based polymer of the present invention.

[0023] Figure 4 It is a cycle data diagram of the battery of the present invention. DETAILED DESCRIPTION

[0024] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0025] Embodiment 1,

[0026] Reference Figure 1 and Figure 2 , respectively, the structures of the aldehyde-containing structure compound and the amino-containing structure compound. Take 0.3 mol of terephthalaldehyde and 0.2 mol of 1,3,5-tri(4-aminophenyl)benzene, dissolve them in NMP solution, then take 10 g of sulfide polyacrylic acid and disperse it in the above NMP organic solvent. Add 1.5 mol of acetic acid as an initiator to promote the polymerization reaction between the aldehyde group and the amino group to generate Figure 3 The porous imine polymer was in situ coated on the sulfide polyacrylic acid positive electrode material. The prepared porous imine-coated sulfide polyacrylic acid material was used as the positive electrode material. Lithium metal was selected as the negative electrode, and the PP diaphragm was used as the battery diaphragm. According to the conventional battery assembly process, the positive electrode, the negative electrode and the diaphragm were assembled into a lithium metal battery. The charge and discharge test was carried out in the voltage range of 1-3V. At 0.2C, the reversible discharge specific capacity was as high as 1597mAh / g. Figure 4 After 200 cycles, the reversible discharge capacity is 1327 mAh / g, and the capacity retention rate is as high as 83%.

[0027] Embodiment 2,

[0028] Take 0.3 mol of 2,3,5,6-tetrafluorobenzaldehyde and 0.2 mol of tetramethyl-p-phenylenediamine, dissolve them in DMF solution, then take 10g of sulfide polyacrylic acid and disperse them in the above DMF organic solvent. Add 1.3 mol of hydrochloric acid as an initiator to promote the polymerization reaction between aldehyde groups and amino groups to generate porous imine polymers and in situ coat them on the sulfide polyacrylic acid positive electrode material. The prepared porous imine-coated sulfide polyacrylic acid material is used as the positive electrode material. Lithium metal is selected as the negative electrode and PP diaphragm is used as the battery diaphragm. According to the conventional battery assembly process, the positive electrode, negative electrode and diaphragm are assembled into a lithium metal battery. The charge and discharge test was carried out in the voltage range of 1-3V. At 0.2C, the reversible discharge specific capacity was as high as 1588mAh / g. After 200 cycles, the reversible discharge specific capacity was 1356mAh / g, and the capacity retention rate was as high as 85%.

[0029] Embodiment 3,

[0030] Take 0.3 mol of 3,3,5,5-tetraaldehyde biphenyl and 0.2 mol of tetrafluoro-p-phenylenediamine, dissolve them in chloroform solution, then take 10 g of sulfide polyacrylic acid and disperse them in the above chloroform organic solvent. Add 1.2 mol of sulfuric acid as an initiator to promote the polymerization reaction between aldehyde groups and amino groups to generate porous imine polymers and in situ coat them on the sulfide polyacrylic acid positive electrode material. The prepared porous imine-coated sulfide polyacrylic acid material is used as the positive electrode material. Lithium metal is selected as the negative electrode and PP diaphragm is used as the battery diaphragm. According to the conventional battery assembly process, the positive electrode, negative electrode and diaphragm are assembled into a lithium metal battery. The charge and discharge test was carried out in the voltage range of 1-3V. At 0.2C, the reversible discharge specific capacity was as high as 1456mAh / g. After 200 cycles, the reversible discharge specific capacity was 1244mAh / g, and the capacity retention rate was as high as 85%.

[0031] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A method for preparing a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material, characterized in that: The following steps are involved: S1, taking an aldehyde-containing structural compound, an amino-containing structural compound and a sulfur-based polymer positive electrode material, dispersing them in an organic solvent to prepare a mixed solution; S2, adding acid to the mixed solution prepared in step S1 to initiate polymerization of aldehyde groups and amino groups to form a porous imine-polymer-coated sulfur-based polymer positive electrode material.

2. The method for preparing a porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material according to claim 1, characterized in that: The sulfur-based polymer positive electrode material is one of sulfided polyacrylic acid, sulfided polyaniline, sulfided polyacrylonitrile, sulfided polytetravinylpyridine, sulfided-1,3-diisopropenylbenzene, sulfided poly(3-hexylthiophene-2,5-diyl), sulfided-1,3-diethynylbenzene, sulfided aminophenol-formaldehyde resin, and sulfided poly(1,2,4,5-4-amino)benzene; The organic solvent is NMP, DMF, chloroform, tetrachloroethane, dichloromethane and ethylene glycol dimethyl ether; the acid is one of hydrochloric acid, sulfuric acid, nitric acid and acetic acid; The molar ratio of the compound containing an aldehyde structure to the compound containing an amino structure is 1:10-10:1; The mass ratio of the positive electrode material of the porous imine polymer and the sulfur-based polymer is (0.01-3):

10.

3. A porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material, characterized in that: The preparation method is described in any one of claims 1 to 2.

4. The porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material according to claim 3, characterized in that: Assemble the battery as the positive electrode material.

5. The porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material according to claim 3, characterized in that: The negative electrode of the assembled battery is lithium metal, sodium metal and potassium metal; The diaphragms are PP, PE, PP / PE / PP / , PETE and PEO diaphragms.

6. The porous imine-based polymer in-situ coated sulfur-based polymer positive electrode material according to claim 3, characterized in that: The assembled battery is applied to lithium metal batteries, lithium ion batteries, sodium ion batteries, sodium metal batteries, potassium ion batteries, and potassium metal batteries.

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