Red phosphorus@graphyne composite material, and preparation method and application thereof

Abstract

The application discloses a red phosphorus-graphdiyne composite material and a preparation method and application thereof, and belongs to the technical field of battery materials. The preparation method comprises the following steps: placing carbon paper and red phosphorus in a vacuum sealed reactor and performing heat treatment; in the process of heat treatment, sublimation and desublimation of the red phosphorus occur, and red phosphorus nanoparticles after desublimation are covered on the surface of the carbon paper; electrochemical deposition is performed on the obtained carbon paper covered with red phosphorus, so that the surface of the carbon paper is covered with copper elements, which are used as catalysts for growth of graphdiyne; the obtained carbon paper is added into a hexaalkynylbenzene solution, and reaction is performed in a dark environment; and unreacted copper elements are washed away by using an acidic iron salt mixed solution, so that the red phosphorus-graphdiyne composite material is obtained. The composite material has wide application prospects in lithium ion batteries and other ion battery negative materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery materials, in particular to a red phosphorus@graphdiyne composite material and a preparation method and application thereof. BACKGROUND

[0002] In 2010, the Li Yuliang research group of the Institute of Chemistry, Chinese Academy of Sciences successfully synthesized graphdiyne (GDY) for the first time. Copper was used as a growth substrate and catalyst, and hexaheptylbenzene was used for coupling reaction on the surface of copper foil to prepare a large-area graphdiyne film. Graphdiyne is a two-dimensional carbon allotrope with sp and sp 2 co-hybridization, and the extremely uneven charge distribution on its surface can bring unlimited active sites. Meanwhile, the natural band gap and porous structure also give GDY natural advantages in photocatalysis, energy conversion, electrochemical reduction and storage.

[0003] Red phosphorus has a high theoretical specific capacity (2596 mAh / g) as a negative electrode material in lithium-ion batteries, which is much higher than that of traditional graphite materials (372 mAh / g). It is also low in price and environmentally friendly. It shows great application advantages, especially in the era of high-capacity battery development. However, the low intrinsic conductivity of red phosphorus and the large volume effect during charging and discharging limit its capacity utilization, long-term cycle stability and rate performance. These defects result in low utilization of active materials, serious electrode pulverization and poor cycle stability of the electrode.

[0004] In view of this, the present application aims to provide a method for in-situ preparation of red phosphorus@graphdiyne composite material on carbon paper to better solve the above problems. SUMMARY

[0005] To solve the above technical problems, the present application provides a red phosphorus@graphdiyne composite material and a preparation method and application thereof. In the present application, red phosphorus is evaporated and condensed on carbon paper, so that nanoscale red phosphorus particles are uniformly distributed on the carbon paper. Nanosizing improves the electrochemical activity and long-term cycle stability of red phosphorus. In addition, by growing graphdiyne on red phosphorus, the red phosphorus is coated, which further inhibits the volume expansion of red phosphorus during charging and discharging of the lithium-ion battery negative electrode, and builds a layer of high-conductivity physical shielding layer to inhibit the shedding of nanometer red phosphorus. The carbon paper prepared by the method can be directly used as a lithium-ion battery negative electrode, which saves other additives and solvents used in the process of manufacturing lithium-ion battery negative electrodes, and has good performance and economic benefits.

[0006] The first object of the present application is to provide a method for preparing a red phosphorus@graphdiyne composite material, which comprises the following steps:

[0007] S1, carbon paper and red phosphorus are placed in a vacuum sealed reactor for heat treatment, in the process of heat treatment, red phosphorus sublimation and desublimation phenomenon occurs, the red phosphorus nanoparticles after desublimation evenly cover the surface of the carbon paper;

[0008] S2, the obtained carbon paper with red phosphorus surface is subjected to electrochemical deposition, and copper element is uniformly grown on the surface of red phosphorus;

[0009] S3, the carbon paper obtained in step S2 is added to a hexaalkynylbenzene (HEB) solution, and the carbon paper is used as the substrate for the growth of graphdiyne, and the reaction is carried out at room temperature in a dark environment, and then the unreacted copper element is washed away with an acidic iron salt mixed solution to obtain a red phosphorus@graphdiyne composite material.

[0010] In some embodiments of the present application, in step S1, the carbon paper is a hydrophilic carbon paper.

[0011] In some embodiments of the present application, in step S1, the vacuum sealed reactor is a quartz tube.

[0012] The process of heat treatment is as follows: the temperature is raised from room temperature to 550-800 DEG C at a rate of 3-5 DEG C / min, and then the temperature is kept for 2-6 hours; then the temperature is lowered to 240-260 DEG C at a rate of 1-3 DEG C / min, and then the temperature is kept for 12-30 hours, and then the temperature is naturally cooled down.

[0013] In some embodiments of the present application, in step S2, the current density of electrochemical deposition is 50-100 mA, and the time is 5-10 min.

[0014] In some embodiments of the present application, in step S3, the concentration of the hexaalkynylbenzene (HEB) solution is 0.2-5 mg / mL.

[0015] The solvent of the hexaalkynylbenzene (HEB) solution is an organic solvent.

[0016] In some embodiments of the present application, in step S3, the temperature of the graphdiyne growth reaction is 20-30 DEG C, and the reaction time is 48-60 h.

[0017] In some embodiments of the present application, in step S3, the acidic iron salt mixed solution includes an acid and an iron salt, the concentration of the acid is 0.1-1-mol / L, and the concentration of the iron salt is 0.5-2 mol / L.

[0018] The second object of the present application is to provide a red phosphorus@graphdiyne composite material, which takes carbon paper as a substrate material, the surface of the substrate material is covered with red phosphorus, and the surface of the red phosphorus is in situ wrapped with graphdiyne.

[0019] The third object of the present application is to provide an electrode sheet, and the negative electrode sheet is the red phosphorus@graphdiyne composite material.

[0020] A fourth object of the present application is to provide a battery including the electrode sheet.

[0021] The above technical solution of the present application has the following advantages compared with the prior art:

[0022] 1. The preparation method provided by the present application realizes in-situ preparation of red phosphorus@graphdiyne composite material on carbon paper by simple vapor deposition of red phosphorus on carbon paper and growth of graphdiyne. Carbon paper can be used as a current collector of a battery electrode sheet as a good conductor, so that the prepared CP / RP@GDY can be directly used as a lithium ion battery negative electrode or other battery negative electrode, thereby eliminating the use of other additives and solvents in the battery negative electrode manufacturing process and reducing the cost.

[0023] 2. The composite material prepared by the present application is attached to the surface of carbon paper by simple vapor deposition of uniform nano red phosphorus, and then graphdiyne is grown on the surface of red phosphorus to coat the red phosphorus. Nanocrystallization improves the electrochemical activity and long-term cycle stability of red phosphorus, and the coated graphdiyne further inhibits the volume expansion of red phosphorus during the charging and discharging process of the lithium ion battery negative electrode, and constructs a high-conductivity physical shielding layer to inhibit the shedding of nano red phosphorus, effectively improving the electrochemical performance of red phosphorus, and having a wide application prospect in lithium ion battery and other battery negative electrode materials. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, wherein,

[0025] Figure 1 SEM image of the CP / RP electrode prepared in Comparative Example 1 of the present application;

[0026] Figure 2 SEM image of the CP / RP@GDY composite electrode prepared in Example 1 of the present application;

[0027] Figure 3 Raman image of the Raman characterization test image of the material obtained in the present application and the comparative example;

[0028] Figure 4 Battery impedance performance test image;

[0029] Figure 5 Battery cycle performance image. DETAILED DESCRIPTION

[0030] In order to solve the technical problems pointed out in the background art, the present application proposes the following technical solutions to achieve the purpose of the present application:

[0031] The present invention provides a method for preparing a red phosphorus@graphene composite material, which comprises the following steps:

[0032] S1. placing carbon paper and red phosphorus in a vacuum-sealed reactor for heat treatment. During the heat treatment, the red phosphorus undergoes sublimation and desublimation, and the desublimated red phosphorus nanoparticles are evenly covered on the surface of the carbon paper.

[0033] S2. Electrochemically depositing the obtained carbon paper with the surface covered with red phosphorus to uniformly grow copper on the red phosphorus;

[0034] S3. Add the carbon paper obtained in step S2 to the hexynylbenzene (HEB) solution, use the carbon paper as a substrate for graphyne growth, react in a dark environment at room temperature, and then wash away unreacted copper with an acidic iron salt mixed solution to obtain a red phosphorus@graphyne composite material.

[0035] In a specific embodiment of the present invention, in step S1, the carbon paper is hydrophilic carbon paper.

[0036] In a specific embodiment of the present invention, in step S1, the vacuum sealed reactor is a quartz tube;

[0037] The heat treatment process is as follows: heating from room temperature to 550-800°C at a rate of 3-5°C / min, and then keeping the temperature for 2-6 hours. For example, the rate can be 3°C / min, 3.5°C / min, 4°C / min, 4.5°C / min, 5°C / min, etc., or any interval between any two values; the temperature can be: 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, etc., or any interval between any two values; the time can be 2h, 3h, 4h, 5h, 6h, etc., or any interval between any two values. any interval value; then cool to 240-260°C at a rate of 1-3°C / min, and keep warm for 12-30h, and then cool naturally; illustratively, the rate can be 1°C / min, 1.5°C / min, 2°C / min, 2.5°C / min, 3°C / min, etc., or any interval value between any two values; the temperature can be 240°C, 250°C, 260°C, etc., or any interval value between any two values; the time can be 12h, 15h, 20h, 25h, 30h, etc., or any interval value between any two values.

[0038] In a specific embodiment of the present invention, in step S2, the current density of the electrochemical deposition is 50-100 mA, and the time is 5-10 minutes.

[0039] In the embodiment of the present application, in step S3, the concentration of the hexaalkynylbenzene (HEB) solution is 0.2-5 mg / mL. For example, it can be 0.2 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL, 4 mg / mL, 4.5 mg / mL, 5 mg / mL, or any interval value between any two numerical values.

[0040] In the embodiment of the present application, in step S3, the reaction condition in the dark environment is that the temperature of the graphdiyne growth reaction is 20-30℃, and the reaction time is 48-60 h.

[0041] In the embodiment of the present application, in step S1, the solvent of the hexaalkynylbenzene (HEB) solution is an organic solvent.

[0042] Further, the organic solvent is selected from dichloromethane and / or pyridine; and the volume ratio of dichloromethane to pyridine is 2:1-5:3.

[0043] In the embodiment of the present application, in step S3, the acidic iron salt mixed solution comprises an acid and an iron salt, the concentration of the acid is 0.1-1 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, or any interval value between any two numerical values; and the concentration of the iron salt is 0.5-2 mol / L, for example, it can be 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, or any interval value between any two numerical values.

[0044] The present application also provides a red phosphorus@graphdiyne composite material, which comprises a carbon paper as a base material, red phosphorus covering the surface of the base material, and graphdiyne in situ wrapping the surface of the red phosphorus.

[0045] In the present application, the nanocrystallization improves the electrochemical activity and long-term cycle stability of red phosphorus, the coated graphdiyne further inhibits the volume expansion of red phosphorus during the charging and discharging process of the lithium ion battery negative electrode, at the same time, the graphdiyne has abundant pore channels for ion transmission, the use of graphdiyne to coat the red phosphorus not only limits the red phosphorus, but also enhances the conductivity of the material and improves the electronic conductivity, thereby effectively improving the electrochemical performance of the red phosphorus.

[0046] The application further provides an electrode sheet, which is the red phosphorus-graphdiyne composite material, namely a CP / RP@GDY composite electrode.

[0047] In the application, when the carbon paper material of the in-situ prepared red phosphorus-graphdiyne composite material is applied to a lithium ion battery negative electrode material, the carbon paper can be used as a current collector of the battery electrode sheet as a good conductor, so that the prepared CP / RP@GDY composite electrode can be directly used as a lithium ion battery negative electrode or other battery negative electrode, thereby eliminating other auxiliary agents and solvents used in the battery negative electrode manufacturing process, and thus being more environmentally friendly and improving economic benefits, and having a wide application prospect in lithium ion batteries and other batteries.

[0048] The application further provides a battery comprising the electrode sheet.

[0049] The application will be further described below in conjunction with the drawings and specific examples, so that those skilled in the art can better understand the application and implement it, but the examples are not intended to limit the application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for describing specific embodiments only and is not intended to be limiting of the application.

[0051] The numerical values disclosed in the embodiments of the application are approximate values, not definite values. Within the error or experimental conditions, all values within the error range can be included without being limited to the specific numerical values disclosed in the embodiments of the application.

[0052] Example 1

[0053] The preparation method of the graphite diyne / red phosphorus composite electrode material prepared in-situ on the carbon paper provided in the embodiment comprises the following preparation steps:

[0054] S1, evaporating and condensing red phosphorus on the carbon paper

[0055] A 10 cm long, 1.1 cm wide and 0.19 mm thick carbon paper is placed in a quartz tube with 150 mg of commercial red phosphorus, the quartz tube is vacuum sealed, and then the vacuum quartz tube is heat treated. The heat treatment process is as follows: from 30 DEG C to 550 DEG C at a heating rate of 3 DEG C / min, holding for 4 hours, then cooling to 260 DEG C at a rate of 1 DEG C / min, holding for 24 hours, and then naturally cooling to room temperature. The cooled quartz tube is knocked to take out the carbon paper, which is treated with carbon disulfide and ethanol ultrasonically in sequence, the ultrasonic power is 4 whz, the time is 5 minutes, and finally vacuum drying at 60 DEG C for 8 hours to obtain the carbon paper loaded with red phosphorus (CP / RP).

[0056] S2, depositing copper on carbon paper by electrochemical deposition

[0057] S2, depositing copper on carbon paper by electrochemical deposition

[0058] S3, growing graphdiyne on carbon paper

[0059] S3, growing graphdiyne on carbon paper

[0060] The CP / RP@GDY composite material is obtained by depositing nanoscale red phosphorus on carbon paper and growing graphdiyne in situ, and the obtained CP / RP@GDY composite material is directly used as a composite electrode.

[0061] The materials prepared in Example 1 and Comparative Example 1 are subjected to structural characterization, and the characterization results are shown in Figure 1 、 Figure 2 and Figure 3 .

[0062] Figure 1 The carbon paper / red phosphorus (CP / RP) electrode prepared in Comparative Example 1 can be seen to be uniformly loaded with red phosphorus nanoparticles on the skeleton of the carbon paper after evaporation and condensation. Figure 2 The carbon paper / red phosphorus@graphdiyne composite electrode prepared in Example 1 can be seen to be well coated with graphdiyne by in-situ growth of graphdiyne. Figure 3 The Raman characterization of Example 1 and Comparative Example 1 can be seen to show that the characteristic peaks of red phosphorus at 300-500 cm -1 have disappeared after coating with graphdiyne, further proving that the red phosphorus is well coated with graphdiyne.

[0063] Example 2

[0064] The preparation method of the carbon paper in-situ prepared graphdiyne / red phosphorus composite electrode material provided in this embodiment comprises the following preparation steps:

[0065] S1, evaporating and condensing red phosphorus on carbon paper

[0066] A piece of carbon paper with a length of 10 cm, a width of 1.1 cm, and a thickness of 0.19 mm was placed in a quartz tube with 200 mg of commercial red phosphorus. The quartz tube was vacuum-sealed, and then the vacuum quartz tube was subjected to heat treatment. The heat treatment process was as follows: the temperature was raised from 30°C to 650°C at a rate of 3°C / min, held for 4 h, then lowered to 260°C at a rate of 1°C / min, held for 24 h, and then naturally cooled to room temperature. The cooled quartz tube was knocked to take out the carbon paper, which was treated with carbon disulfide and ethanol ultrasonically, with an ultrasonic power of 4 wHz and a time of 5 min, and finally vacuum dried at 60°C for 8 h to obtain the carbon paper loaded with red phosphorus (CP / RP).

[0067] S2, electrochemical deposition of copper on the carbon paper

[0068] The carbon paper obtained in S1 was subjected to electrochemical deposition using a two-electrode system, with a deposition current of 120 mA and a deposition time of 10 min, so that copper was uniformly grown on the surface of the carbon paper.

[0069] S3, growth of graphdiyne on the carbon paper

[0070] 6 mg of hexaethynylbenzene (HEB) powder was dissolved in a mixed solution of 5 mL of pyridine and 3 mL of dichloromethane to obtain a 0.75 mg / mL hexaethynylbenzene (HEB) solution, and the carbon paper obtained in S2 was added, with copper as the substrate for the growth of graphdiyne, and the reaction was carried out in a dark environment at 25°C for 54 h. After the reaction was completed, the carbon paper was washed with ethanol for 3 times, and then washed with a mixed solution of 0.5 mol / L hydrochloric acid and ferric chloride to remove the unreacted copper, and finally washed with water and alcohol, and dried to obtain the carbon paper with the red phosphorus@graphdiyne composite material grown on the surface of the carbon paper, i.e., the CP / RP@GDY composite material.

[0071] Example 3

[0072] The preparation method of the graphdiyne / red phosphorus composite electrode material prepared in situ on the carbon paper provided by the embodiment comprises the following preparation steps:

[0073] S1, evaporation and condensation treatment of red phosphorus on the carbon paper

[0074] A piece of carbon paper with a length of 10 cm, a width of 1.1 cm, and a thickness of 0.19 mm was placed in a quartz tube with 200 mg of commercial red phosphorus. The quartz tube was vacuum-sealed, and then the vacuum quartz tube was subjected to heat treatment. The heat treatment process was as follows: the temperature was raised from 30°C to 650°C at a rate of 3°C / min, held for 4 h, then lowered to 260°C at a rate of 1°C / min, held for 24 h, and then naturally cooled to room temperature. The cooled quartz tube was knocked to take out the carbon paper, which was treated with carbon disulfide and ethanol ultrasonically, with an ultrasonic power of 4 wHz and a time of 5 min, and finally vacuum dried at 60°C for 8 h to obtain the carbon paper loaded with red phosphorus (CP / RP).

[0075] S2, electrochemical deposition of copper on carbon paper

[0076] The carbon paper obtained in S1 was electrochemically deposited using a two-electrode system, with a deposition current of 80 mA and a deposition time of 10 min, to make the copper grow uniformly on the surface of the carbon paper.

[0077] S3, growth of graphdiyne on carbon paper

[0078] 8 mg of hexa-ethynyl benzene (HEB) powder was dissolved in 5 mL of pyridine and 3 mL of dichloromethane to obtain a 1 mg / mL solution of hexa-ethynyl benzene (HEB), which was added to the carbon paper obtained in S2, with copper as the substrate for the growth of graphdiyne, and reacted at 25°C in the dark for 60 h. After the reaction, the carbon paper was washed with ethanol three times, and then washed with a mixed solution of 0.5 mol / L hydrochloric acid and ferric chloride to remove the unreacted copper, and finally washed with water and alcohol, and dried, to obtain a carbon paper with red phosphorus-graphdiyne composite material grown on the surface of the carbon paper, i.e., a CP / RP@GDY composite material.

[0079] Comparative Example 1

[0080] This comparative example prepared an electrode with red phosphorus deposited on carbon paper but without growth of graphdiyne, including the following steps:

[0081] A carbon paper with a length of 10 cm, a width of 1.1 cm, and a thickness of 0.19 mm was placed in a quartz tube with a certain amount of 150 mg of commercial red phosphorus, and the quartz tube was vacuum-sealed and then heat-treated in a vacuum. During the heat treatment, the red phosphorus in the quartz tube sublimed and then condensed, and the condensed red phosphorus nanoparticles uniformly covered the surface of the carbon paper. The heat treatment process was as follows: the temperature was raised from 30°C to 550°C at a rate of 3°C / min, held for 4 h, then lowered to 260°C at a rate of 1°C / min, held for 24 h, and then naturally cooled to room temperature. The carbon paper was taken out by knocking the cooled quartz tube, and was treated with carbon disulfide and ethanol by ultrasonic treatment, with an ultrasonic power of 4 wHz and a treatment time of 5 min, and finally vacuum-dried at 60°C for 8 h, to obtain a carbon paper loaded with red phosphorus (CP / RP).

[0082] Comparative Example 2

[0083] This comparative example prepared an electrode of ordinary commercial red phosphorus using the traditional method of making electrode sheets from powder materials, including the following steps:

[0084] 16 mg of commercial red phosphorus, 2 mg of polyvinylidene fluoride, and 2 mg of conductive carbon black were dispersed and stirred in an appropriate amount of N-methyl pyrrolidone solution to prepare electrode slurry, which was coated on a circular carbon paper with a diameter of 8 mm using a glass rod, and was placed in a vacuum drying oven at 80°C for 12 h to obtain an electrode.

[0085] Application Example

[0086] The CP / RP@GDY composite electrode prepared in Example 1 was directly applied to a lithium ion battery negative material, and the specific steps were as follows:

[0087] The CP / RP@GDY composite electrode was cut into a direct 8 mm round piece and transferred to an Ar-filled glove box. A button cell was assembled with the CP / RP@GDY composite electrode as the positive electrode, lithium metal as the negative electrode, Whatman glass fiber as the separator, and a 1M LiPF6 solution of EC-DMC-DEC (the volume ratio of EC, DMC and DEC was 1:1:1, and 5wt.% FEC was added) as the electrolyte, and the battery cycle performance was measured on a LAND CT2001A system.

[0088] The comparative example 1 and comparative example 2 were cut into 8 mm round electrodes, and the battery assembly and test were carried out in the same steps as Example 1.

[0089] (1) Battery impedance test

[0090] The battery impedance performance test results are shown in Figure 4 , and the curve is composed of a semicircle in the high frequency region and a straight line in the low frequency region. By comparing the diameter of the semicircle in the high frequency region for evaluating the electrode resistance, it can be seen that the diameter of the semicircle of Example 1 is smaller than that of Comparative Example 1, that is, the electrode resistance of Example 1 is smaller than that of Comparative Example 1, which proves that the graphite yne coating effectively improves the conductivity of red phosphorus.

[0091] (2) Battery cycle test: first activate the battery (charge and discharge activation for 4 times), then test the electrochemical performance under the current density of 1A / g and the voltage window of 0.01-3.00V, and the specific results are shown in Table 1 and Figure 5 . (The same size of carbon paper was used as the current collector in the example and the comparative example, and the specific capacity was calculated according to the mass of the active material.)

[0092] Table 1

[0093]

[0094]

[0095] From Table 1 and Figure 5 , it can be seen that during the battery cycle test, the discharge specific capacity of Example 1 is higher than that of the comparative example, and by comparing the discharge specific capacity of the 70th cycle, Example 1 can still maintain a specific capacity of 2012.3mAh / g, has better cycle stability and electrochemical performance, which proves that the present application effectively improves the problem of volume expansion of red phosphorus during charging and discharging, and the prepared carbon paper / red phosphorus@graphite yne composite material is a good lithium ion battery negative electrode.

[0096] As can be seen from the above specific examples and experimental characterization results, the carbon paper is used as a matrix to evaporate and condense red phosphorus, and the carbon paper is uniformly loaded with nano red phosphorus, and then the graphite diyne is grown in situ to coat the red phosphorus. The graphite diyne has rich pores for ion transmission, and the use of graphite diyne to coat the red phosphorus can not only confine the red phosphorus, but also enhance the conductivity of the material, improve the rate performance and cycle stability of the battery. In addition, the carbon paper / red phosphorus@graphite diyne composite electrode prepared by the present application can be directly used as a negative electrode of a lithium ion battery, saving the additives and solvents used in the electrode preparation process, being more environmentally friendly and improving economic benefits, and having a broad application prospect in lithium ion batteries and other batteries.

[0097] Obviously, the above examples are only examples for clearly illustrating, and are not limited to the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing a red phosphorus@graphene composite material, characterized in that: The following steps are involved: S1. placing carbon paper and red phosphorus in a vacuum-sealed reactor for heat treatment. During the heat treatment, the red phosphorus undergoes sublimation and desublimation, and the desublimated red phosphorus nanoparticles are evenly covered on the surface of the carbon paper. S2. electrochemically depositing the obtained carbon paper with the surface covered with red phosphorus to uniformly grow copper on the surface of the red phosphorus; S3. Add the carbon paper obtained in step S2 to the hexynylbenzene solution, use the carbon paper as a substrate for graphyne growth, react in a dark environment at room temperature, and then wash away unreacted copper with an acidic iron salt mixed solution to obtain a red phosphorus@graphyne composite material.

2. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S1, the carbon paper is hydrophilic carbon paper.

3. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S1, the vacuum sealed reactor is a quartz tube; The heat treatment process is as follows: heating from room temperature to 550-800°C at a rate of 3-5°C / min, then keeping warm for 2-6 hours; then cooling to 240-260°C at a rate of 1-3°C / min, keeping warm for 12-30 hours, and then cooling naturally.

4. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S2, the current density of the electrochemical deposition is 50-150 mA, and the time is 5-15 minutes.

5. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S3, the temperature of the graphyne growth reaction is 20-30° C., and the reaction time is 48-60 h.

6. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S3, the concentration of the hexaynylbenzene solution is 0.2-5 mg / mL; The solvent of the hexaynylbenzene solution is an organic solvent.

7. The method for preparing a red phosphorus@graphene composite material according to claim 1, wherein: In step S3, the acidic iron salt mixed solution includes acid and iron salt, the concentration of the acid is 0.1-1 mol / L; the concentration of the iron salt is 0.5-2 mol / L.

8. A red phosphorus@graphene composite material obtained by the preparation method according to any one of claims 1 to 7, characterized in that: Carbon paper is used as a base material, the surface of the base material is covered with red phosphorus, and the surface of the red phosphorus is in-situ wrapped with graphyne.

9. An electrode sheet, characterized in that: The electrode sheet is the red phosphorus@graphene composite material described in claim 8.

10. A battery, characterized in that: Comprising the electrode sheet as claimed in claim 9.

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