Black phosphorus-carbon composite material and preparation method and application thereof

Abstract

The application provides a black phosphorus-carbon composite material and a preparation method and application thereof. The preparation method comprises the following steps: reacting black phosphorus and carbon material in an organic amine solvent at 80-200 DEG C to obtain the black phosphorus-carbon composite material. The black phosphorus-carbon composite material is prepared by using a solvothermal method. The reaction condition is mild, the operation is simple, the equipment is simple, and the scale-up is easy. When the black phosphorus-carbon composite material is used as a negative electrode material of a lithium ion battery, the black phosphorus-carbon composite material has good rate and cycle performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery negative electrode materials, and particularly relates to a black phosphorus-carbon composite material and a preparation method and application thereof. BACKGROUND

[0002] Lithium ion secondary batteries are widely used energy storage devices due to their environmental friendliness, high energy density, long cycle life and other advantages. In order to improve the performance indicators of lithium ion secondary batteries, including service life, fast charging and discharging capability, high and low temperature performance and use safety, the modification treatment of negative electrode materials is crucial. Among them, carbon materials such as graphite are studied more. However, the theoretical specific capacity of the current commercial graphite negative electrode is only 372 mAh / g, which is difficult to meet the growing demand.

[0003] Phosphorus is widely available and has abundant reserves, and the theoretical lithium storage specific capacity of elemental phosphorus is as high as 2596 mAh / g, about 7 times that of commercial graphite negative electrode materials. Black phosphorus, as an elemental phosphorus material, has a high Li + diffusion rate and is suitable as a negative electrode material for lithium ion batteries. Pure black phosphorus has been proven to be useful as a negative electrode material, but it has poor electrical conductivity and large volume change during charging and discharging. If black phosphorus is effectively compounded with carbon materials, the shortcomings of each as a battery negative electrode material can be improved. At present, the preparation of black phosphorus and carbon composite negative electrode materials is mostly achieved by ball milling, which is a cumbersome process and difficult to scale up. Therefore, it is urgent to develop a simple process for preparing black phosphorus and carbon composite negative electrode materials that can be easily scaled up.

[0004] CN115498165A discloses a black phosphorus-based composite electrode and a preparation method and application thereof. The black phosphorus-based composite electrode is composed of black phosphorus nanosheets, carbon materials and TiO x . In the preparation method, the covalent bonding of black phosphorus and carbon materials is achieved by the huge energy of the solvothermal reaction, and then TiO x is spin-coated on the surface of the phosphorus-carbon composite material by a sol-gel method, and then "zero strain" Li y TiO x is generated in situ during the first discharge process. In the above technical solution, water, ethanol, N,N-dimethylformamide, N-methylpyrrolidone, acetonitrile or dimethyl sulfoxide act as dispersants and do not directly participate in the covalent bonding reaction of black phosphorus and carbon materials; after the solvothermal reaction process, the final black phosphorus-based composite electrode can be obtained only after the sol-gel spin-coating step of TiO x , which is a cumbersome process and takes a long time to prepare. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a black phosphorus-carbon composite material, a preparation method and application thereof. The black phosphorus-carbon composite material is obtained by one-step solvothermal method, and has the advantages of mild reaction condition, simple operation, simple equipment and easy amplification. The prepared lithium ion battery has good rate and cycle performance.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is:

[0007] In one aspect, the present application provides a preparation method of a black phosphorus-carbon composite material, comprising the following steps:

[0008] The black phosphorus and the carbon material are reacted in an organic amine solvent at 80-200 DEG C to obtain the black phosphorus-carbon composite material.

[0009] In some specific embodiments, the reaction temperature of the black phosphorus and the carbon material in the organic amine solvent is 80 DEG C, 100 DEG C, 120 DEG C, 140 DEG C, 160 DEG C, 180 DEG C, 200 DEG C or any temperature therebetween.

[0010] As a preferred embodiment, the black phosphorus is selected from at least one of black phosphorus micro powder, black phosphorus nanosheet and black phosphorus quantum dot.

[0011] As a preferred embodiment, the carbon material is selected from at least one of graphene, graphene oxide, carbon nanotube, graphite and carbon black.

[0012] As a preferred embodiment, the organic amine is selected from at least one of 1,2-propylenediamine, N-ethylethylenediamine, N-aminoethylpiperazine and 1,3-bis(aminomethyl)cyclohexane.

[0013] As a preferred embodiment, the mass ratio of the black phosphorus and the carbon material is 1:100-10:1.

[0014] In some specific embodiments, the mass ratio of the black phosphorus and the carbon material is 1:100, 1:90, 1:80, 1:50, 1:40, 1:10, 1:1, 10:1 or any ratio therebetween.

[0015] As a preferred embodiment, the mass ratio of the black phosphorus and the organic amine is 1:10-5:1.

[0016] In some specific embodiments, the mass ratio of the black phosphorus and the organic amine is 1:10, 1:5, 1:2, 1:1, 3:1, 5:1 or any ratio therebetween.

[0017] As a preferred embodiment, the reaction time is 3-100h.

[0018] In some specific embodiments, the reaction time is 3h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, 100h, or any time therebetween.

[0019] As a preferred embodiment, the method further comprises post-treatment; the post-treatment comprises washing and drying.

[0020] In another aspect, the present application provides the black phosphorus-carbon composite material prepared by the above method.

[0021] In another aspect, the present application provides the use of the above black phosphorus-carbon composite material in the preparation of lithium ion batteries, in particular, in the preparation of negative electrode materials of lithium ion batteries.

[0022] The above technical solution has the following advantages or beneficial effects:

[0023] (1) In the present application, the organic amine containing chemically active amino groups is used as the reaction solvent. In the solvothermal reaction process of black phosphorus and carbon material, the organic amine not only plays a dispersing role as a solvent, but also participates in the covalent bonding reaction of black phosphorus and carbon material, thereby accelerating the reaction rate of covalent bonding and improving the reaction degree of covalent bonding. In addition, the prepared black phosphorus-carbon composite material contains nitrogen element. Therefore, when the black phosphorus-carbon composite material provided by the present application is used as an electrode material to embed lithium, it reacts with lithium to form a lithium-nitrogen compound with high ionic conductivity and good wettability, thereby reducing the impedance and realizing stable contact between the material and the electrolyte.

[0024] (2) The black phosphorus-carbon composite material provided by the present application is prepared by one-step solvothermal method. Compared with the traditional ball milling process and the two-step process of “solvothermal → sol-gel spin coating”, the black phosphorus-carbon composite material has the advantages of mild reaction conditions, simple operation, simple equipment, short production cycle, and easy expansion.

[0025] (3) The phosphorus raw material and carbon material used in the present application are low in price and widely available, and the organic amine used can be recycled, thereby reducing the production cost.

[0026] (4) The black phosphorus-carbon composite material provided by the present application can significantly alleviate the volume change of phosphorus during the charging and discharging process of the battery, and has good electrical conductivity, excellent charge and discharge cycle performance, and rate performance. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a scanning electron microscope image of the black phosphorus-carbon composite material in Example 1 of the present application;

[0028] Figure 2 is an X-ray diffraction spectrum of the black phosphorus-carbon composite material in Example 1 of the present application;

[0029] Figure 3 Infrared spectrum of the black phosphorus-carbon composite material in Example 3 of the present application;

[0030] Figure 4 Electrochemical cycle performance of the black phosphorus-carbon composite material in Example 1 of the present application;

[0031] Figure 5 Electrochemical rate performance of the black phosphorus-carbon composite material in Example 1 of the present application;

[0032] Figure 6 Electrochemical impedance spectrum of the black phosphorus-carbon composite material in Example 7 and Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0033] The following examples are merely exemplary of some of the applications of the present application and therefore should not be considered to be limiting of its scope, as manifested by the appended claims. Based on the instant application, any and all modifications, variations or equivalent arrangements which do not depart from the spirit or scope of the application should be considered to be within the scope of the present application.

[0034] In the present application, all the equipment and raw materials, unless specified, can be purchased from the market or commonly used in the industry. The methods in the following examples, unless specified, are the conventional methods in the art.

[0035] Example 1

[0036] Black phosphorus nanosheets and graphite were added to N-ethyl ethylenediamine, wherein the mass ratio of black phosphorus nanosheets and graphite was 7:3, and the mass ratio of black phosphorus and N-ethyl ethylenediamine was 1:10. The reaction was carried out at 120°C for 24h, and after the reaction was completed, it was naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid was vacuum dried to obtain black phosphorus-carbon composite material 1.

[0037] Example 2

[0038] Black phosphorus micro powder and carbon nanotubes were added to 1,2-propylenediamine, wherein the mass ratio of black phosphorus micro powder and carbon nanotubes was 1:100, and the mass ratio of black phosphorus micro powder and 1,2-propylenediamine was 1:5. The reaction was carried out at 80°C for 100h, and after the reaction was completed, it was naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid was vacuum dried to obtain black phosphorus-carbon composite material 2.

[0039] Example 3

[0040] The black phosphorus quantum dots and graphene are added into 1,3-bis(aminomethyl)cyclohexane, wherein the mass ratio of the black phosphorus quantum dots and graphene is 1:1, the mass ratio of the black phosphorus quantum dots and 1,3-bis(aminomethyl)cyclohexane is 5:1, the reaction is carried out at 150°C for 48h, after the reaction is completed, the reaction system is naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid is vacuum dried to obtain the black phosphorus-carbon composite material 3.

[0041] Example 4

[0042] The black phosphorus micro powder and carbon black are added into N-aminoethyl piperazine, wherein the mass ratio of the black phosphorus micro powder and carbon black is 10:1, the mass ratio of the black phosphorus micro powder and N-aminoethyl piperazine is 1:1, the reaction is carried out at 200°C for 3h, after the reaction is completed, the reaction system is naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid is vacuum dried to obtain the black phosphorus-carbon composite material 4.

[0043] Example 5

[0044] The black phosphorus quantum dots, black phosphorus nanosheets and graphene oxide are added into 1,3-bis(aminomethyl)cyclohexane, wherein the mass ratio of the black phosphorus quantum dots, black phosphorus nanosheets and graphene oxide is 2:3:1, the mass ratio of the black phosphorus and 1,3-bis(aminomethyl)cyclohexane is 2:1, the reaction is carried out at 100°C for 72h, after the reaction is completed, the reaction system is naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid is vacuum dried to obtain the black phosphorus-carbon composite material 5.

[0045] Example 6

[0046] The black phosphorus micro powder and graphene are added into 1,2-propanediamine, 1,3-bis(aminomethyl)cyclohexane, wherein the mass ratio of the black phosphorus micro powder and graphene is 5:1, the mass ratio of the black phosphorus micro powder and 1,2-propanediamine, 1,3-bis(aminomethyl)cyclohexane is 1:4:1, the reaction is carried out at 180°C for 24h, after the reaction is completed, the reaction system is naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid is vacuum dried to obtain the black phosphorus-carbon composite material 6.

[0047] Example 7

[0048] The black phosphorus nanosheets and carbon nanotubes are added into N-ethyl ethylenediamine, wherein the mass ratio of the black phosphorus nanosheets and carbon nanotubes is 1:20, the mass ratio of the black phosphorus nanosheets and N-ethyl ethylenediamine is 2:1, the reaction is carried out at 100°C for 90h, after the reaction is completed, the reaction system is naturally cooled to room temperature, washed with anhydrous ethanol, and the residual solid is vacuum dried to obtain the black phosphorus-carbon composite material 7.

[0049] Example 8

[0050] The black phosphorus quantum dots and the carbon black were added into 1,2-propylenediamine, wherein the mass ratio of the black phosphorus quantum dots and the carbon black was 1:10, and the mass ratio of the black phosphorus quantum dots and the 1,2-propylenediamine was 1:2, and the reaction was carried out at 200℃ for 12h, and after the reaction was completed, the reaction was naturally cooled to room temperature, and the residual solid was washed with anhydrous ethanol, and the black phosphorus-carbon composite material 8 was obtained after the residual solid was dried in vacuum.

[0051] Example 9

[0052] The black phosphorus micro powder and the graphene were added into N-aminoethylpiperazine, wherein the mass ratio of the black phosphorus micro powder and the graphene was 1:50, and the mass ratio of the black phosphorus micro powder and the N-aminoethylpiperazine was 1:1, and the reaction was carried out at 80℃ for 24h, and after the reaction was completed, the reaction was naturally cooled to room temperature, and the residual solid was washed with anhydrous ethanol, and the black phosphorus-carbon composite material 9 was obtained after the residual solid was dried in vacuum.

[0053] Comparative Example 1

[0054] The black phosphorus-carbon composite material in the present comparative example was prepared in the same manner as in Example 7, except that the N-ethyl ethylenediamine was replaced by N-methyl pyrrolidone.

[0055] The performance of the black phosphorus-carbon composite materials prepared in the above examples and comparative examples was tested and characterized, wherein the scanning electron microscope image of the black phosphorus-carbon composite material 1 was as shown in Figure 1 It can be seen that the black phosphorus nanosheets are uniformly dispersed on the surface of the graphite, and the planar size of the black phosphorus nanosheets is about 200nm. As shown in the X-ray diffraction spectrum of Figure 2 It can be seen that the crystallinity of the black phosphorus-carbon composite material 1 is poor, and the characteristic diffraction peaks of the black phosphorus and the graphite are weak. The infrared spectrum of the black phosphorus and carbon composite negative electrode material 3 shows a characteristic peak of P-N-C at 1030cm -1 nearby, indicating that the nitrogen element in the 1,3-bis(aminomethyl)cyclohexane participates in the covalent bonding reaction of the black phosphorus and the carbon material.

[0056] The application further assembles lithium ion half-batteries by using the black phosphorus-carbon negative electrode material prepared in the above examples and comparative examples and referring to the method in the reference (DOI: 10.1126 / science.aav5842), tests the cycle performance and rate performance, and finds that the specific capacity of the black phosphorus-carbon negative electrode material 1 is 1335 mAh / g after 70 cycles at a current density of 1 A / g, and the capacity retention rate reaches 92% (compared with the 3rd cycle, i.e. the 1st cycle at 1 A / g), indicating that it has good cycle performance. In addition, it can realize the charging and discharging process in the range of 0.2-50 A / g, and the specific capacity at 10 A / g is as high as 1260 mAh / g. Therefore, the black phosphorus-carbon composite negative electrode material 1 has excellent rate performance and can realize the fast charging and discharging process. The applicant believes that its good electrochemical performance benefits from the good composite between black phosphorus and graphite, which improves the conductivity of black phosphorus and to some extent inhibits the large volume expansion effect of black phosphorus in the charging and discharging process, showing the advantages of the technical solutions in the specification.

[0057] The application further determines the electrochemical impedance spectra of the black phosphorus-carbon composite materials prepared in the above examples and comparative examples, wherein the electrochemical impedance spectra of the black phosphorus-carbon composite material 7 and the black phosphorus-carbon composite material prepared in the comparative example are determined after 20 cycles at 1 A / g by referring to the method in the reference (DOI: 10.1126 / science.aav5842). Figure 6 It can be seen that the black phosphorus-carbon composite material 7 has smaller electrochemical impedance and faster lithium ion diffusion rate than the comparative example, indicating that the material derives lithium-nitrogen compounds in the electrochemical process, and its high ionic conductivity and good wettability reduce the impedance and realize stable contact with the electrolyte.

[0058] The above only describes the preferred embodiments of the application, and it should be noted that for ordinary skilled persons in the art, some improvements and refinements can be made without departing from the principles of the application, and these improvements and refinements should also be regarded as the protection scope of the application.

Claims

1. A method for producing a black phosphorus-carbon composite material, the black phosphorus-carbon composite material produced by the method containing nitrogen, characterized by, The method comprises the following steps: The black phosphorus and the carbon material are reacted in an organic amine solvent at 80-200 DEG C to obtain the black phosphorus and carbon composite material, the organic amine is selected from at least one of 1,2-propylenediamine, N-ethyl ethylenediamine, N-aminoethyl piperazine and 1,3-bis(amino methyl) cyclohexane, the mass ratio of the black phosphorus and the organic amine is 1:10-5:1, and the mass ratio of the black phosphorus and the carbon material is 1:100-10:

1.

2. The production method according to claim 1, characterized by, The black phosphorus is selected from at least one of black phosphorus micro powder, black phosphorus nanosheet and black phosphorus quantum dot.

3. The production method according to claim 1, characterized by, The carbon material is selected from at least one of graphene, graphene oxide, carbon nanotube, graphite and carbon black.

4. The preparation method according to claim 1, characterized in that, The reaction time is 3-100 h.

5. The preparation method according to claim 1, characterized in that, The method further comprises post-treatment, and the post-treatment comprises washing and drying.

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