阅读说明：本技术 一种ptcda改性树脂基炭材料及其制备方法和应用 (PTCDA modified resin-based carbon material and preparation method and application thereof ) 是由 徐斌 周环宇 孙宁 朱奇珍 常夏青 于 2021-06-30 设计创作，主要内容包括：本发明提供了一种PTCDA改性树脂基炭材料及其制备方法和应用,属于复合材料技术领域。本发明以碱溶液作为溶解PTCDA的溶剂,浓硫酸能够使PTCDA转化为PTCA有机酸；在浓硫酸的催化作用下,PTCA有机酸与树脂通过酯化反应进行充分交联复合；对交联产物进行碳化处理时,PTCDA相可有效抑制树脂基炭材料石墨化畴的形成和增长,提高炭材料的无序度和石墨微晶层间距,从而制备得到一种石墨畴结构无序、缺陷少的PTCDA改性树脂基炭材料。与树脂直接热解制备的炭材料相比,本发明制备的PTCDA改性树脂基炭材料作为钠离子电池的负极材料时,不仅拥有高的比容量和高的首次库伦效率,还表现出优异的循环和倍率性能。(The invention provides a PTCDA modified resin-based carbon material and a preparation method and application thereof, belonging to the technical field of composite materials. According to the invention, an alkali solution is used as a solvent for dissolving PTCDA, and the PTCDA can be converted into PTCA organic acid by concentrated sulfuric acid; under the catalytic action of concentrated sulfuric acid, PTCA organic acid and resin are fully crosslinked and compounded through esterification reaction; when the cross-linked product is carbonized, the PTCDA phase can effectively inhibit the formation and growth of graphitized domains of the resin-based carbon material, and improve the disorder degree of the carbon material and the graphite microcrystal interlamellar spacing, so that the PTCDA modified resin-based carbon material with disordered graphite domain structure and few defects is prepared. Compared with the carbon material prepared by direct pyrolysis of resin, the PTCDA modified resin-based carbon material prepared by the invention has high specific capacity and high first coulombic efficiency and also shows excellent cycle and rate performance when being used as the cathode material of the sodium ion battery.)

1. A preparation method of PTCDA modified resin-based carbon material comprises the following steps:

(1) mixing PTCDA, an alkaline solution, resin and concentrated sulfuric acid, and carrying out esterification reaction to obtain a cross-linked product;

(2) carbonizing the cross-linked product obtained in the step (1) to obtain a PTCDA modified resin-based carbon material; the carbonization is carried out under the protection of inert atmosphere.

2. The method according to claim 1, wherein the concentration of the alkaline solution in the step (1) is 0.3 to 1M.

3. The method according to claim 1, wherein the resin in the step (1) comprises a phenolic resin, an epoxy resin or a hydroxyl polyester.

4. The production method according to claim 1 or 3, wherein the mass ratio of PTCDA to resin in the step (1) is 1:1 to 1: 10.

5. The preparation method according to claim 1, wherein the temperature of the esterification reaction in the step (1) is 100 to 120 ℃ and the time of the esterification reaction is 6 to 10 hours.

6. The method according to claim 1, wherein the carbonization in step (2) is carried out at a temperature of 800 to 1400 ℃ for 1 to 10 hours.

7. The production method according to claim 1 or 6, wherein the temperature increase rate of the temperature increase to the carbonization temperature in the step (2) is 2 to 10 ℃/min.

8. The PTCDA modified resin-based carbon material prepared by the preparation method of any one of claims 1 to 7, wherein the PTCDA modified resin-based carbon material is soft/hard composite carbon formed by combining PTCDA-based soft carbon and resin-based hard carbon.

9. The PTCDA modified resin-based carbon material according to claim 8, wherein the (002) crystal face interlayer distance in the PTCDA modified resin-based carbon material is 0.39-0.40 nm, and the specific surface area of the PTCDA modified resin-based carbon material is 3-5 m²/g。

10. Use of the PTCDA modified resin-based carbon material according to claim 8 or 9 in the negative electrode material of sodium-ion batteries.

Technical Field

The invention relates to the technical field of composite materials, in particular to a PTCDA modified resin-based carbon material and a preparation method and application thereof.

Background

The sodium element has similar properties with the lithium element, and compared with the lithium ion battery, the sodium element has rich sodium reserves and low cost, so the sodium ion battery is considered as a novel secondary battery oriented to large-scale energy storage. The hard carbon has stable structure, low cost, abundant resources and simple preparation process, and is the sodium ion battery cathode material with the most practical prospect. The resin has low cost and high carbon content, and is a typical hard carbon precursor. However, the resin-based hard carbon has relatively ordered structure, long graphite domain, small interlayer spacing and many defects, and when the resin-based hard carbon is used as a negative electrode material of a sodium ion battery, the resin-based hard carbon has low capacity and large first irreversible capacity, and cannot meet the practical application of the sodium ion battery.

Many studies have been conducted around improving the sodium storage performance of resin-based carbon materials. Such as: the patent 'sodium ion battery hard carbon negative electrode material based on phenolic resin and preparation method and application thereof' discloses a preparation method of spherical phenolic resin-based hard carbon; phenolic resin is dissolved in ethanol, is subjected to hydrothermal pre-carbonization and is subjected to high-temperature carbonization under protective gas to obtain spherical hard carbon which shows excellent sodium storage performance when used as a negative electrode material of a sodium ion battery. However, the hydrothermal method is troublesome in process, relatively harsh in implementation conditions, high in cost and not easy for industrial production. Qiu et al (adv. energy mater.2018,8,1702434) ball-mill phenolic resin, asphalt and NaCl by wet method, mix them, and carbonize them at high temperature to obtain a three-dimensional porous hard carbon, 5Ag, with high specific capacity and excellent rate capability^-1Still has 97mAh g under high current density^-1However, the large specific surface area of the lithium ion battery leads to excessive electrolyte consumption in the first charge and discharge process, the first coulombic efficiency is only 60%, and industrial application is difficult to realize. Therefore, in the existing technology for modifying the resin-based carbon negative electrode material of the sodium-ion battery, although the spherical structure is constructed by a hydrothermal method, the electrochemistry of the resin-based carbon material can be improved to a certain extentChemical properties, but the process is complicated and industrial production is difficult. The doping method and other methods can improve the sodium storage capacity and simultaneously lead to the reduction of the first coulombic efficiency. Therefore, it is urgently needed to develop a preparation method of a resin-based carbon material which is simple in process and easy to industrialize, so that the prepared carbon material has high sodium storage capacity, high first coulombic efficiency, and good cycle performance and rate capability.

Disclosure of Invention

The PTCDA modified resin-based carbon material provided by the invention is simple in process and easy to industrially apply, and has higher sodium storage capacity, first coulombic efficiency, better cycle performance and rate capability when being used as a negative electrode material of a sodium-ion battery.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of a PTCDA modified resin-based carbon material, which comprises the following steps:

(1) mixing PTCDA, an alkaline solution, resin and concentrated sulfuric acid, and carrying out esterification reaction to obtain a cross-linked product;

(2) carbonizing the cross-linked product obtained in the step (1) to obtain a PTCDA modified resin-based carbon material; the carbonization is carried out under the protection of inert atmosphere.

Preferably, the concentration of the alkaline solution in the step (1) is 0.3-1M.

Preferably, the resin in step (1) comprises phenolic resin, epoxy resin or hydroxy polyester.

Preferably, the mass ratio of PTCDA to resin in the step (1) is 1: 1-1: 10.

Preferably, the temperature of the esterification reaction in the step (1) is 100-120 ℃, and the time of the esterification reaction is 6-10 h.

Preferably, the carbonization temperature in the step (2) is 800-1400 ℃, and the carbonization time is 1-10 h.

Preferably, the temperature rise rate of the temperature rise to the carbonization temperature in the step (2) is 2-10 ℃/min.

The invention also provides the PTCDA modified resin-based carbon material prepared by the preparation method in the technical scheme, wherein the PTCDA modified resin-based carbon material is soft/hard composite carbon formed by combining PTCDA-based soft carbon and resin-based hard carbon.

Preferably, the (002) crystal face interlayer spacing in the PTCDA modified resin-based carbon material is 0.39-0.40 nm, and the specific surface area of the PTCDA modified resin-based carbon material is 3-5 m²/g。

The invention also provides application of the PTCDA modified resin-based carbon material in the technical scheme in a negative electrode material of a sodium-ion battery.

The invention provides a preparation method of a PTCDA modified resin-based carbon material, which comprises the following steps: mixing PTCDA, an alkaline solution, resin and concentrated sulfuric acid, and carrying out esterification reaction to obtain a blending solution; carrying out solid-liquid separation on the obtained blending solution to obtain a cross-linked product; carbonizing the obtained cross-linked product to obtain a PTCDA modified resin-based carbon material; the carbonization is carried out under the protection of inert atmosphere. According to the invention, an alkali solution is used as a solvent for dissolving PTCDA, and concentrated sulfuric acid can introduce abundant carboxyl groups on the surface of PTCDA and convert the PTCA into PTCA organic acid; under the catalytic action of concentrated sulfuric acid, PTCA organic acid and resin are fully crosslinked and compounded through esterification reaction, so that the thermal stability of a resin molecular chain of a crosslinked product can be improved; when the crosslinked product is carbonized, the PTCDA phase can effectively inhibit the formation and growth of graphitized domains of the resin-based carbon material, improve the disorder degree of the carbon material and the graphite microcrystal layer spacing, and effectively avoid the defects generated in the molten state process, so that the PTCDA modified resin-based carbon material with disordered graphite domain structure and few defects is prepared. Compared with the carbon material prepared by direct pyrolysis of resin, the electrochemical performance of the PTCDA modified resin-based carbon material prepared by the invention is obviously improved.

Experimental results show that the PTCDA modified resin-based carbon material obtained by the modification preparation method provided by the invention can show 308.7mAh g at a current density of 0.1C when being used as a negative electrode of a sodium-ion battery^-1The first coulombic efficiency can reach 78 percent, and the high specific capacity shows excellent cycling stabilityThe capacity retention after 100 cycles at a current density of 0.2C was 98.9%. The 3,4,9, 10-perylene tetracarboxylic dianhydride (PTCDA) and the resin raw materials used in the invention are common raw materials in industry, are easy to obtain, have simple and easily-controlled preparation process, and are suitable for industrial large-scale production; the obtained carbon material has small specific surface area and high compactness, and when the carbon material is used as a negative electrode material of a sodium ion battery, the carbon material not only has high specific capacity and high first coulombic efficiency, but also shows excellent cycle and rate capability.

Drawings

FIG. 1 is an XRD pattern of a PTCDA modified resin-based carbon material prepared in example 1 of the present invention;

FIG. 2 is a TEM image of a PTCDA modified resin-based carbon material prepared in example 1 of the present invention;

FIG. 3 is a graph showing the isothermal adsorption curve of the PTCDA modified resin-based carbon material prepared in example 1 of the present invention;

FIG. 4 is an infrared spectrum of a phenolic resin, PTCDA organic acid and a crosslinked product used in example 1 of the present invention;

fig. 5 is a graph showing rate charge and discharge curves of the battery prepared in application example 1 of the present invention;

fig. 6 is a graph showing a cycle curve of a battery prepared in application example 1 of the present invention;

fig. 7 is a graph of rate performance of a battery prepared in application example 1 of the present invention;

FIG. 8 is an XRD pattern of a phenolic resin-based carbon material prepared according to comparative application example 1 of the present invention;

FIG. 9 is a TEM image of a phenolic resin-based carbon material prepared in comparative application example 1 of the present invention;

FIG. 10 is a graph showing isothermal adsorption of a phenolic resin-based carbon material prepared in comparative application example 1;

fig. 11 is a graph showing rate charge and discharge curves of a battery prepared in comparative application example 1 according to the present invention;

fig. 12 is a graph showing rate charge and discharge curves of a battery prepared in application example 2 of the present invention;

fig. 13 is a graph showing rate charge and discharge curves of the battery prepared in application example 3 of the present invention.

Detailed Description

The invention provides a preparation method of a PTCDA modified resin-based carbon material, which comprises the following steps:

(1) mixing PTCDA, an alkaline solution, resin and concentrated sulfuric acid, and carrying out esterification reaction to obtain a cross-linked product;

(2) carbonizing the cross-linked product obtained in the step (1) to obtain a PTCDA modified resin-based carbon material; the carbonization is carried out under the protection of inert atmosphere.

The invention mixes PTCDA, alkaline solution, resin and concentrated sulfuric acid to carry out esterification reaction, and obtains a cross-linked product.

In the invention, the PTCDA is 3,4,9, 10-perylenetetracarboxylic dianhydride, the PTCDA is introduced into the resin through an esterification reaction, the existence of the PTCDA phase can effectively inhibit the formation and growth of graphitized domains of the resin in the carbonization process, improve the disorder degree of the carbon material and the graphite microcrystal layer spacing, and effectively avoid the defects generated in the molten state process, thereby preparing the PTCDA modified resin-based carbon material with disordered graphite domain structure and few defects, and further improving the electrochemical performance of the PTCDA modified resin-based carbon material. The source of PTCDA is not particularly limited in the present invention and commercially available products well known to those skilled in the art may be used.

In the present invention, the alkaline solution is preferably a NaOH solution or a KOH solution. In the present invention, the alkaline solution functions to dissolve PTCDA.

In the present invention, the concentration of the alkaline solution is preferably 0.3 to 1M, and more preferably 0.5 to 1M. In the present invention, when the concentration of the alkaline solution is within the above range, it is more advantageous to sufficiently dissolve PTCDA, thereby facilitating the subsequent reaction to be sufficiently performed. In the present invention, the volume of the alkaline solution is not particularly limited, and the PTCDA can be sufficiently dissolved by adjusting the mass of PTCDA to be used. In the present invention, when the concentration of the alkaline solution is 0.3 to 1M, the ratio of the mass of PTCDA to the volume of the alkaline solution is preferably 1g (100 to 500) mL, more preferably 1g (100 to 300) mL.

In the present invention, the resin preferably includes a phenol resin, an epoxy resin or a hydroxyl polyester. In the present invention, the resin serves as a carbon source for the carbon material. The source of the resin is not particularly limited in the present invention, and commercially available products known to those skilled in the art may be used. In the present invention, when the resin is a phenol resin, the type of the phenol resin is preferably a thermoplastic phenol resin, and the type of the thermoplastic phenol resin preferably includes 217, 2123, or 2402; the thermoplastic phenolic resin of the type described above is preferably purchased from Jingnan resin Co., Jinghai county, Tianjin. When the resin is epoxy resin, the type of the epoxy resin preferably comprises E bisphenol epoxy resin E42, E44 or E51, and the type of the epoxy resin is preferably purchased from Qingdao Baichen New Material science and technology Co., Ltd; when the resin is a hydroxy polyester, the hydroxy polyester is preferably of a type including H10, H20, or H30, and the hydroxy polyester of the type described above is preferably purchased from santo moll chemical company, ltd. In the invention, when the type of the resin is the type, the PTCDA modified resin-based carbon material with disordered graphite domain structure and few defects can be obtained more conveniently.

In the invention, the mass ratio of PTCDA to resin is preferably 1: 1-1: 10, and more preferably 1: 5-1: 10. In the invention, when the mass ratio of the PTCDA to the resin is in the range, the PTCDA modified resin-based carbon material with disordered graphite domain structure and less defects can be obtained more favorably.

In the invention, the mass concentration of the concentrated sulfuric acid is preferably 70-98%, and more preferably 80-98%. In the invention, on one hand, the concentrated sulfuric acid can introduce abundant carboxyl groups on the surface of PTCDA to obtain PTCA organic acid, and on the other hand, the concentrated sulfuric acid can catalyze the PTCA organic acid to perform esterification reaction with resin to obtain a cross-linked product.

The using amount of the concentrated sulfuric acid is not specially limited, and the concentrated sulfuric acid can be adjusted according to the requirement. In the invention, the concentration of sulfuric acid in the mixed solution obtained by mixing PTCDA, the alkaline solution, the resin and concentrated sulfuric acid is preferably 3-6M, and more preferably 4-5M. In the present invention, when the concentration of sulfuric acid in the mixed solution obtained by mixing PTCDA, the alkaline solution, the resin, and concentrated sulfuric acid is in the above range, it is more advantageous to promote the reaction to be sufficiently performed.

The operation mode of mixing the PTCDA, the alkaline solution, the resin and the concentrated sulfuric acid is not particularly limited in the invention, and the components can be uniformly mixed by adopting a mixing mode well known by a person skilled in the art.

In the present invention, the mixing of PTCDA, alkaline solution, resin and concentrated sulfuric acid preferably comprises: dissolving PTCDA in an alkaline solution to obtain a PTCDA alkaline solution; slowly adding concentrated sulfuric acid into the PTCDA alkali solution to obtain an acid-treated PTCDA solution; mixing the acid treated PTCDA solution with a resin.

In the present invention, the method of dissolving PTCDA in an alkaline solution is not particularly limited, and PTCDA can be dissolved in an alkaline solution by a method known to those skilled in the art.

According to the invention, deionized water is preferably added to the PTCDA alkali solution before concentrated sulfuric acid is slowly added to the PTCDA alkali solution. In the present invention, the addition of deionized water to the PTCDA base solution can prevent excessive exotherms when the base solution reacts with concentrated sulfuric acid. The volume of the deionized water is not specially limited, and the deionized water can be adjusted according to the requirement.

In the present invention, during the process of slowly adding concentrated sulfuric acid into the PTCDA alkali solution, carboxylic acid groups can be introduced on the surface of PTCDA, so the present invention has no special limitation on the mixing time of the PTCDA alkali solution and concentrated sulfuric acid.

After PTCDA, alkaline solution, resin and concentrated sulfuric acid are mixed, the mixed solution obtained by mixing is subjected to esterification reaction to obtain a cross-linked product.

In the invention, the temperature of the esterification reaction is preferably 100-120 ℃, and more preferably 110-115 ℃; the time of the esterification reaction is preferably 6-10 hours, and more preferably 8-10 hours. In the present invention, when the temperature and time of the esterification reaction are within the above ranges, the esterification reaction can be sufficiently completed. The apparatus for the esterification reaction is not particularly limited in the present invention, and a reaction apparatus known to those skilled in the art may be used. In the invention, as the PTCDA can modify the resin to inhibit the formation and growth of graphitized domains of the resin-based carbon material in the carbonization process, improve the disorder degree of the carbon material and the spacing of graphite microcrystalline layers, and effectively avoid the defects generated in the molten state process, the method does not need to adopt a hydrothermal reaction in the step, but only adopts a conventional reaction device for finishing esterification.

In the present invention, the esterification reaction is preferably carried out under stirring. In the present invention, the stirring can promote the esterification reaction. The stirring speed is not particularly limited, and all the components can be uniformly mixed during the esterification reaction.

According to the invention, preferably, after the esterification reaction, the system obtained by the esterification reaction is subjected to solid-liquid separation and drying in sequence to obtain a cross-linked product.

The operation mode of the solid-liquid separation and drying is not particularly limited in the present invention, and the operation mode of the solid-liquid separation and drying known to those skilled in the art can be adopted. In the present invention, the solid-liquid separation is preferably suction filtration. In the invention, the drying is preferably vacuum drying, and the temperature of the vacuum drying is preferably 60-100 ℃, and more preferably 80-100 ℃; the vacuum drying time is preferably 4-12 hours, and more preferably 6-10 hours. In the present invention, the solid-liquid separation and drying are of the above type, which enables to obtain a dried crosslinked product.

After a cross-linked product is obtained, the cross-linked product is carbonized to obtain the PTCDA modified resin-based carbon material.

In the present invention, the carbonization is performed under the protection of an inert atmosphere. The kind of the gas of the inert atmosphere is not particularly limited in the present invention, and it is sufficient to provide an inert atmosphere as well known to those skilled in the art. In the present invention, the gas of the inert atmosphere is preferably nitrogen, helium or argon. In the present invention, the inert atmosphere can prevent the crosslinking product from being oxidized during carbonization.

In the invention, the carbonization temperature is preferably 800-1400 ℃, and more preferably 1000-1200 ℃; the carbonization time is preferably 1-10 h, and more preferably 5-8 h. In the present invention, when the carbonization temperature and time are within the above ranges, the crosslinked product can be sufficiently carbonized to obtain the PTCDA modified resin-based carbon material.

In the present invention, the heating rate for heating to the carbonization temperature is preferably 2 to 10 ℃/min, and more preferably 5 to 10 ℃/min. In the invention, when the temperature rise rate is in the range, the structure collapse and the reduction of the mechanical property of the PTCDA modified resin-based carbon material caused by too high temperature rise rate can be prevented, and the insufficient carbonization of a cross-linked product caused by too low temperature rise rate can be prevented.

According to the invention, an alkali solution is used as a solvent for dissolving PTCDA, and concentrated sulfuric acid can introduce abundant carboxyl groups on the surface of PTCDA and convert the PTCA into PTCA organic acid; under the catalytic action of concentrated sulfuric acid, PTCA organic acid and resin are fully crosslinked and compounded through esterification reaction, so that the thermal stability of a resin molecular chain can be improved; when the red solid precipitate obtained by the esterification reaction is carbonized, the PTCDA phase can effectively inhibit the formation and growth of graphitized domains of the resin-based carbon material, improve the disorder degree of the carbon material and the spacing of graphite microcrystalline layers, and effectively avoid the defects generated in the molten state process, so that the PTCDA modified resin-based carbon material with disordered graphite domain structure and few defects is prepared.

The invention also provides the PTCDA modified resin-based carbon material prepared by the preparation method in the technical scheme, wherein the PTCDA modified resin-based carbon material is soft/hard composite carbon formed by combining PTCDA-based soft carbon and resin-based hard carbon.

In the invention, the mass ratio of the PTCDA and the resin determines the mass of the PTCDA-based soft carbon and the resin-based hard carbon of the PTCDA modified resin-based carbon material finally formed, so the invention has no special limitation on the mass ratio of the PTCDA-based soft carbon and the resin-based hard carbon in the PTCDA modified resin-based carbon material.

In the invention, the (002) crystal plane interlayer spacing in the PTCDA modified resin-based carbon material is preferably 0.39-0.40 nm. In the present invention, the interlamellar spacing of the graphite crystallites in the PTCDA-modified resin-based carbon material has a large value relative to the interlamellar spacing of the graphite crystallites of conventional resin-based carbon materials.

In the present invention, the PTCDA is modifiedThe specific surface area of the resin-based charcoal material is preferably 3-5 m²A concentration of 4 to 5m²(ii) in terms of/g. And PTCDA modified resin-based carbon material has a small specific surface area.

The PTCDA modified resin-based carbon material provided by the invention has larger interlayer spacing of graphite microcrystals, and when the PTCDA modified resin-based carbon material is used as a negative electrode material of a sodium-ion battery, the PTCDA modified resin-based carbon material has high sodium storage capacity and high first coulombic efficiency due to the larger interlayer spacing of the graphite microcrystals. The PTCDA modified resin-based carbon material has a small specific surface area, and when the PTCDA modified resin-based carbon material is used as a negative electrode material of a sodium-ion battery, the PTCDA modified resin-based carbon material shows high sodium storage capacity and high first coulombic efficiency due to the large interlayer spacing of graphite microcrystals.

The invention also provides application of the PTCDA modified resin-based carbon material in the technical scheme in a negative electrode material of a sodium-ion battery.

The application method of the PTCDA modified resin-based carbon material in the negative electrode material of the sodium-ion battery is not particularly limited, and the carbon material known by the technical personnel in the field can be used as the application method in the negative electrode material of the sodium-ion battery.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

0.8g of PTCDA was dissolved in 100mL of a 0.5M NaOH solution, 65mL of deionized water was added thereto, 85mL of a 98% concentrated sulfuric acid solution was slowly added thereto so that the concentration of sulfuric acid in the resulting mixed solution was 6M, and after stirring uniformly, 4.8g of 217 type phenol novolac resin powder was added thereto. Heating the blending solution at 110 ℃ and stirring for 8h, carrying out suction filtration and collection on the precipitate, and drying the precipitate at 80 ℃ in vacuum for 6h to obtain a red solid precipitate (namely a crosslinked product). And under the protection of inert atmosphere formed by argon, heating the crosslinked product to 1200 ℃ at the heating rate of 5 ℃/min, and preserving the heat for 3h to obtain the PTCDA modified resin-based carbon material. (the mass ratio of PTCDA to the phenolic resin is 1: 6).

An X-ray diffractometer is used for testing the PTCDA modified resin-based carbon material prepared in the example 1, and the XRD pattern of the PTCDA modified resin-based carbon material prepared in the example 1 is shown in figure 1. The interlayer spacing of the (002) crystal face of the modified resin-based carbon material is larger and is 0.392nm as calculated from the XRD pattern of figure 1.

The PTCDA modified resin-based carbon material prepared in example 1 is observed by a high-resolution transmission electron microscope, and a TEM image of the PTCDA modified resin-based carbon material prepared in example 1 is shown in FIG. 2. As can be seen from FIG. 2, the graphite lattice stripes of the PTCDA modified phenolic resin based carbon material are disordered, the lattice stripes are short, and the spacing is large.

The PTCDA modified resin-based carbon material prepared in example 1 was tested with a nitrogen adsorption specific surface tester, and the isothermal adsorption curve of the PTCDA modified resin-based carbon material prepared in example 1 was obtained as shown in fig. 3. As can be seen from FIG. 3, the PTCDA modified phenolic resin based carbon material has a smaller specific surface area of 4.86m²/g。

The phenolic resin, the PTCDA organic acid and the crosslinked product in the mixed solution prepared in example 1 were tested using a fourier infrared spectrometer to obtain an infrared spectrum as shown in fig. 4.

As can be seen from FIG. 4, the phenolic resin is at 1367cm^-1And 3332cm^-1Two absorption peaks exist, which correspond to free-OH and stretching and bending vibration peaks of-OH on the inner side of a benzene ring respectively. PTCA at 1778cm^-1And 3453cm^-1Two absorption peaks corresponding to the stretching and bending vibration peaks of-C ═ O-and-OH, respectively, are present. 1367cm of phenolic resin in the mixture after esterification^-1The absorption peak disappears, 3000-3600 cm^-1The absorption peak of the corresponding-OH is greatly shifted, which indicates that the PTCA organic acid and the phenolic resin are subjected to esterification and crosslinking reaction during heating and stirring.

Application example 1

PTCDA modified phenolic Tree prepared in example 1The lipo-carbon material was ground thoroughly and mixed with sodium carboxymethyl cellulose in a ratio of 95: 5, evenly mixing in a refiner to form slurry, then evenly scraping and coating the slurry on a current collector copper foil, drying and cutting into (10 multiplied by 10) mm²The pole piece of (2). The pole piece is dried for 10 hours at 120 ℃ under the vacuum condition and then transferred to a glove box for standby. The cell was assembled in a glove box under Ar atmosphere, with sodium metal as the counter electrode and 1 mole of NaClO₄And dissolving the solution of ethylene carbonate and diethyl carbonate in 1L volume ratio of 1:1 as electrolyte to assemble the CR2025 button cell.

Test example 1

The battery prepared in application example 1 was subjected to a charge and discharge performance test under the following test conditions: the charging and discharging mode is multiplying power charging; the current density is 0.1C; the discharge cutoff voltage is 0.001V, and the charge cutoff voltage is 3V; the rate charge/discharge curve of the battery prepared in application example 1 is shown in fig. 5. As can be seen from FIG. 5, the reversible specific capacity of the battery prepared in application example 1 was 308.7mAh g^-1The first coulombic efficiency was 78%.

The cycle performance of the battery prepared in corresponding example 1 was tested under the following conditions: the charging mode is multiplying power charging, the current density is 0.2C, the discharging cutoff voltage is 0.001V, and the charging cutoff voltage is 3V. The cycle profile of the battery prepared in application example 1 was shown in fig. 6. As can be seen from FIG. 6, the capacity of the battery prepared in application example 1 was 279.8mAh g after 100 cycles^-1The capacity retention rate is 98.9%, and capacity fading basically does not exist, so that the material is good in cycling stability.

The rate performance of the battery prepared in corresponding example 1 was tested under the following conditions: the charging mode is multiplying power charging, the current density of 0.1C, 0.2C, 0.5C, 1C, 2C and 0.1C is respectively circulated for 5 circles, the discharging cut-off voltage is 0.001V, and the charging cut-off voltage is 3V. The rate performance of the battery prepared in application example 1 was obtained as shown in fig. 7. As can be seen from FIG. 7, the specific capacities of the batteries manufactured in application example 1 at 0.1C, 0.2C, 0.5C, 1C, 2C and 0.1C were 308.5mAh g^-1，287.8mAh g^-1，223.1mAh g^-1，138.3mAh g^-1，84.3mAh g^-1，300.2mAh g^-1Has better rate capability.

Comparative application example 1

Heating 5g of phenolic resin to 1200 ℃ at a heating rate of 5 ℃/min under the protection of argon, and then preserving heat for 3h to obtain the phenolic resin-based carbon material. And fully grinding the prepared carbon material powder, and mixing with sodium carboxymethyl cellulose according to a ratio of 95: 5, evenly mixing in a refiner to form slurry, then evenly scraping and coating the slurry on a current collector copper foil, drying and cutting into (10 multiplied by 10) mm²The pole piece of (2). The pole piece is dried for 10 hours at 120 ℃ under the vacuum condition and then transferred to a glove box for standby. The cell was assembled in a glove box under Ar atmosphere, with sodium metal as the counter electrode and 1 mole of NaClO₄And dissolving the solution of ethylene carbonate and diethyl carbonate in 1L volume ratio of 1:1 as electrolyte to assemble the CR2025 button cell.

Test example 2

The X-ray diffraction was performed on the phenolic resin-based carbon material prepared in comparative application example 1, and the XRD pattern of the phenolic resin-based carbon material prepared in comparative application example 1 is shown in fig. 8. The interlayer spacing of the (002) crystal face of the phenolic resin-based carbon material is smaller and is 0.348nm as calculated from the XRD spectrum of figure 8.

A high-resolution transmission electron microscope test is performed on the phenolic resin-based carbon material prepared in comparative application example 1, and a TEM image of the phenolic resin-based carbon material prepared in comparative application example 1 is shown in fig. 9. As can be seen from FIG. 9, the graphite domains of the phenolic resin-based carbon material are longer, the spacing is smaller, and the graphite domains are relatively ordered.

The nitrogen adsorption specific surface test was performed on the phenolic resin-based carbon material prepared in comparative application example 1, and the isothermal adsorption curve of the phenolic resin-based carbon material prepared in comparative application example 1 was obtained as shown in fig. 10. As can be seen from FIG. 10, the PTCDA modified phenolic resin based carbon material has a large specific surface area of 100.67m²/g。

The battery prepared in comparative application example 1 was subjected to a charge and discharge performance test under the following test conditions: the charging and discharging mode is multiplying power charging; the current density is 0.1C; the discharge cutoff voltage was 0.001V and the charge cutoff voltage was 3V. Comparative application example 1 preparationThe rate charge-discharge curve of the battery of (3) is shown in fig. 11. As can be seen from FIG. 11, the reversible specific capacity of the battery prepared in comparative application example 1 was 150.1mAh g^-1The first coulombic efficiency was 70.9%.

Example 2

0.8g of PTCDA was dissolved in 100mL of a 0.5M NaOH solution, 65mL of deionized water was added, 85mL of a 98% concentrated sulfuric acid solution was slowly added thereto so that the concentration of sulfuric acid in the mixed solution was 6M, and 4.8g of type 217 novolak resin powder was added thereto. Heating and stirring the blending solution at 110 ℃ for 8h, and filtering by suction to collect red solid precipitate. The red solid precipitate was dried at 80 ℃ for 6 h. Wherein the mass ratio of PTCDA to phenolic resin is 1: 6.

and (3) heating the esterification reaction product to 1300 ℃ at the heating rate of 5 ℃/min under the protection of inert gas, and then preserving heat for 3h to obtain the PTCDA modified resin-based carbon material.

Application example 2

The PTCDA modified resin based char material prepared in example 1 was ground thoroughly and mixed with sodium carboxymethylcellulose according to a 95: 5, evenly mixing in a refiner to form slurry, then evenly scraping and coating the slurry on a current collector copper foil, drying and cutting into (10 multiplied by 10) mm²The pole piece of (2). The pole piece is dried for 10 hours at 120 ℃ under the vacuum condition and then transferred to a glove box for standby. The cell was assembled in a glove box under Ar atmosphere, with sodium metal as the counter electrode and 1 mole of NaClO₄And dissolving the solution of ethylene carbonate and diethyl carbonate in 1L volume ratio of 1:1 as electrolyte to assemble the CR2025 button cell.

Test example 3

The battery prepared in the application example 2 was subjected to a charge and discharge performance test under the following test conditions: the charging and discharging mode is multiplying power charging; the current density is 0.1C; the discharge cutoff voltage was 0.001V and the charge cutoff voltage was 3V. The rate charge/discharge curve of the battery prepared in application example 2 is shown in fig. 12. As can be seen from FIG. 12, the reversible specific capacity of the battery prepared in application example 2 was 276mAh g^-1The first coulombic efficiency was 80.4%.

Example 3

0.5g of PTCDA was dissolved in 100mL of a 0.5M NaOH solution, 65mL of deionized water was added, 85mL of a 98% concentrated sulfuric acid solution was slowly added thereto so that the concentration of sulfuric acid in the mixed solution was 6M, and 5g of type 217 novolak resin powder was added thereto. Heating and stirring the blending solution at 110 ℃ for 8h, and filtering by suction to collect red solid precipitate. The red solid precipitate was dried at 80 ℃ for 6 h. Wherein the mass ratio of PTCDA to phenolic resin is 1: 10.

and (3) heating the esterification reaction product to 1200 ℃ at the heating rate of 5 ℃/min under the protection of inert gas, and then preserving heat for 3h to obtain the PTCDA modified resin-based carbon material.

Application example 3

The PTCDA modified resin based char material prepared in example 3 was ground thoroughly and mixed with sodium carboxymethylcellulose according to a 95: 5, evenly mixing in a refiner to form slurry, then evenly scraping and coating the slurry on a current collector copper foil, drying and cutting into (10 multiplied by 10) mm²The pole piece of (2). The pole piece is dried for 10 hours at 120 ℃ under the vacuum condition and then transferred to a glove box for standby. The cell was assembled in a glove box under Ar atmosphere, with sodium metal as the counter electrode and 1 mole of NaClO₄And dissolving the solution of ethylene carbonate and diethyl carbonate in 1L volume ratio of 1:1 as electrolyte to assemble the CR2025 button cell.

Test example 4

The battery prepared in application example 3 was subjected to a charge and discharge performance test under the following test conditions: the charging and discharging mode is multiplying power charging; the current density is 0.1C; the discharge cutoff voltage was 0.001V and the charge cutoff voltage was 3V. The rate charge and discharge curve of the battery prepared in application example 3 was obtained as shown in fig. 13. As can be seen from FIG. 13, the reversible specific capacity of the battery prepared in application example 3 was 287.3mAh g^-1The first coulombic efficiency is 76.2 percent

From the experimental results, the PTCDA modified resin-based carbon material prepared by the preparation method provided by the invention has higher sodium storage capacity, first coulombic efficiency, better cycle performance and rate capability when being used for a sodium ion battery cathode.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.