A porous carbon supported tin phosphide composite material and a preparation method thereof

Abstract

The present application relates to a kind of porous carbon supported tin phosphide composite material and its preparation method, and the preparation method includes: (1) metal Zn source is dissolved in solvent solution with organic ligand and co-precipitation porous metal organic complex MET-6;(2) porous MET-6 is placed into tube furnace, under the protection of inert gas, after high-temperature calcination, porous carbon nitride NPCF is obtained;(3) NPCF is mixed with tin source and phosphorus source according to certain ratio, and high-temperature reaction is generated under inert gas condition to form porous carbon supported tin phosphide.The porous carbon supported tin phosphide synthesized in the present application shows excellent performance as lithium battery negative electrode and sodium battery negative electrode.The method is simple to prepare, process controllable, synthesis cycle is short, suitable for mass production, has significant practical value and good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium ion and sodium ion battery negative electrode materials, and particularly relates to a porous carbon loaded tin phosphide composite material and a preparation method thereof. BACKGROUND

[0002] Since the reserves of fuel type energy such as coal and oil are limited and the combustion process has a certain impact on the environment, clean energy is increasingly needed. Common new energy includes solar energy, tidal energy and wind energy, etc. However, these energies have the characteristics of discontinuity and instability, and in order to solve this problem, these energies need to be stored first before being used.

[0003] As a new type of negative electrode material for lithium ion batteries, tin phosphide mainly undergoes conversion-alloying reaction in the charging and discharging process. Part of the elements can undergo conversion reaction with lithium ions to realize energy storage, and part of the elements can undergo alloying reaction with lithium ions to realize energy storage. The conversion-alloying electrode has a high theoretical specific capacity, usually 700-1000 mAh g -1 , and the specific capacity of individual materials reaches ~2000 mAh g -1 (e.g. the theoretical specific capacity of GeP is as high as 1914 mAh g -1 ). The alloying reaction component and the conversion reaction component usually have a large difference in the reaction voltage with lithium. When the alloying component participates in the reaction, the delithiation component acts as a "hard core" buffer, and when the conversion reaction participates in the reaction, the alloying component acts as a "hard core" buffer. Conversion-alloying reaction materials and alloying reaction and conversion reaction materials face the same scientific problem: the volume change during the charging and discharging process of the material leads to electrode coating cracking and capacity decay. Therefore, the key problems to be solved for tin phosphide as a new type of negative electrode material for lithium ion batteries are volume expansion, low electronic conductivity, slow diffusion kinetics, etc. The existence of these problems makes the cycle stability and coulombic efficiency of the material low, which cannot meet the market demand. SUMMARY

[0004] The technical problem to be solved by the present application is the low cycle stability and coulombic efficiency of the tin phosphide negative electrode material. A negative electrode material is designed and synthesized by using high-energy MOF as a precursor, a nitrogen-rich porous N-C structure formed after high-temperature carbonization of the MOF as a carrier, and Sn4P3 embedded in the porous structure. The material can solve the following problems: 1. The conductive porous carbon formed after high-temperature carbonization of the MOF can improve the electronic conductivity of the negative electrode; 2. The porous carbon can also alleviate the problems of electrode coating cracking and capacity decay caused by the volume expansion of Sn4P3; 3. In the nitrogen-rich N-C after carbonization of the high-energy MOF, the reaction efficiency and reversibility of the conversion reaction in the charging and discharging process are improved through catalysis, thereby improving the cycle stability and coulombic efficiency of the material.

[0005] To solve the above technical problems, the specific schemes of the present application are as follows:

[0006] A porous carbon loaded tin phosphide composite is prepared by the following steps:

[0007] (1) obtaining a metal organic ligand MET-6;

[0008] (2) placing MET-6 into a tube furnace, calcining the product under inert gas protection, washing and drying the calcined product to obtain a carbon nitride carrier NPCF;

[0009] (3) mixing NPCF with a tin source and a solvent, heating, the mass ratio of NPCF to the tin source being 1:5-9, to obtain a NPCF / SnO2 composite; mixing the NPCF / SnO2 composite with a phosphorus source in a certain proportion, calcining under inert gas protection to obtain the final product NPCF@Sn4P3.

[0010] Further, the preparation method of the metal organic ligand MET-6 in step (1) comprises: dissolving zinc salt and 1H-1,2,3-triazole in a solvent composed of ethanol, water, ammonium hydroxide and N,N-dimethylformamide in a certain proportion, reacting at room temperature for a period of time to generate the metal organic ligand MET-6.

[0011] Further, the zinc salt is one of zinc chloride, zinc nitrate, zinc acetate and zinc acetylacetonate;

[0012] Optionally, the ratio of the zinc salt to 1H-1,2,3-triazole is 3-10 g:5-10 mL;

[0013] Optionally, the reaction time is 12-48 h.

[0014] Further, the inert gas in step (2) is nitrogen or argon;

[0015] Optionally, the calcination temperature in step (2) is 700-1000℃, preferably 800-900℃;

[0016] Optionally, the calcination time in step (2) is 1-10 h, preferably 2-5 h;

[0017] Optionally, the washing in step (2) comprises soaking washing with an acid washing solution, deionized water washing and ethanol washing, and drying at 50-100℃ for 10-20 h after washing.

[0018] Further, the mass ratio of NPCF to the tin source in step (3) is 1:5-6;

[0019] Optionally, the atomic molar ratio of Sn in the tin source and P in the phosphorus source is 1:5-15, preferably 1:7-9.

[0020] Further, the solvent in step (3) is an alcohol solution, preferably any one of ethanol, propanol, butanol;

[0021] Optionally, the heating temperature in step (3) is 100-200℃, preferably 120-150℃;

[0022] Optionally, the heating time in step (3) is 5-20h, preferably 8-12h;

[0023] Optionally, the inert gas in step (3) is nitrogen or argon;

[0024] Optionally, the calcination temperature in step (3) is 200-400℃, preferably 250-350℃;

[0025] Optionally, the calcination time in step (3) is 1-30min, preferably 10-20min.

[0026] Further, the composite material is a porous carbon nitride as a porous carrier, and the pore channel is embedded with Sn4P3.

[0027] The present application also protects the preparation method of the porous carbon loaded tin phosphide composite material, comprising the following steps:

[0028] (1) obtaining the metal organic ligand MET-6;

[0029] (2) putting MET-6 into a tube furnace, calcining the product after washing and drying under the protection of inert gas to obtain carbon nitride carrier NPCF;

[0030] (3) mixing NPCF with a tin source and a solvent, then heating to obtain NPCF / SnO2 composite; mixing the NPCF / SnO2 composite with a phosphorus source according to a certain proportion, then calcining under the protection of inert gas to obtain the final product NPCF@Sn4P3.

[0031] The present application also protects a battery negative electrode comprising the porous carbon loaded tin phosphide composite material.

[0032] The present application also protects a battery comprising the battery negative electrode, and the battery is a lithium battery or a sodium battery.

[0033] Beneficial effects: This invention uses carbon nitride as a support, which is mixed with tin and phosphorus sources and then heated to react. The support generates porous carbon nitride, in which nitrogen sites act as catalytic active sites to catalyze the conversion reaction of tin phosphide. At the same time, the tin loaded on the support combines with phosphorus to form Sn4P3 in the pores, thereby realizing the embedding of Sn4P3 in the porous channels. The resulting composite material has high stability.

[0034] Furthermore, the composite material provided by this invention, compared with traditional carbon-modified tin phosphide, improves the electronic conductivity of the composite material by introducing a nitrogen source and using the metal-organic ligand MET-6 as a precursor to form a nitrogen-rich porous NC structure after high-temperature carbonization, which serves as a Sn4P3 carrier.

[0035] Furthermore, the composite material provided by this invention can further improve the charge-discharge performance of the material by controlling the relative amounts of carbon nitride carrier NPCF and tin source. Attached Figure Description

[0036] To more clearly illustrate the technical solution of the present invention, the accompanying drawings will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0037] Figure 1 The NPCF@Sn4P3 prepared in Example 1 was used as a lithium battery material in a lithium-ion battery at 500 mA·g. -1 Cyclic performance at current density.

[0038] Figure 2 The NPCF@Sn4P3 prepared in Example 1 was used as a lithium battery material in a lithium-ion battery with a performance of 1000 mAg. -1 Cyclic performance at current density.

[0039] Figure 3 The NPCF@Sn4P3 prepared in Example 1 was used as a lithium battery material in lithium-ion batteries, and the results were measured at 500 mA·g. -1 1000mA·g -1 Charge-discharge curves at current density.

[0040] Figure 4 The NPCF@Sn4P3 prepared in Example 1 was used as the sodium-ion battery anode material and assembled into a sodium-ion battery, respectively, at 100 mA·g -1 200mA·g -1 500mA·g -1 1000mA·g -1 2000mA·g -1 Rate performance at current density. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it is understood that the present application can be practiced with various modifications within the scope of the present application and the embodiments set forth herein should not be construed as limiting the present application. Unless otherwise indicated, technical or scientific terms used in the examples have the meanings commonly understood by one of ordinary skill in the art in the field of the application, or otherwise have the meanings given herein. Unless otherwise indicated, all reagents or ingredients were obtained from commercial suppliers and used without further purification. In the following examples, unless otherwise indicated, "%" means "weight percent".

[0042] The methods tested in the following examples include:

[0043] Lithium battery performance test: 2032 button cell was used for electrochemical performance test. 80% mass fraction of tin phosphide-based material obtained from the examples or comparative examples, 10% mass fraction of conductive carbon black (Super P) and 10% mass fraction of polyvinylidene fluoride (PVDF) were mixed and ground with an appropriate amount of N-methyl pyrrolidone (NMP) solvent to form a slurry, which was then coated on a copper foil by a doctor blade to obtain a working electrode. The counter electrode and the separator were lithium foil and polypropylene film (Celgard 2400), respectively. The electrolyte base liquid was a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) in a volume ratio of 1:1, with the addition of 5% mass fraction of fluoroethylene carbonate (FEC), and the electrolyte was lithium hexafluorophosphate (LiPF6) with a concentration of 1 mol / L. The battery charge and discharge performance test was carried out on a new Wei test system.

[0044] Sodium battery performance test: according to the mass ratio of negative electrode material, acetylene black, and PVDF in NMP, the mixture was stirred uniformly, then coated on an aluminum foil with a coating machine at a thickness of 0.1 mm, and then the aluminum foil was dried at 120 degrees Celsius under vacuum for 12 hours to obtain an electrode sheet coated with a negative electrode. The electrode sheet was cut to obtain a 12 mm diameter disc, which was compacted with a tablet press at a pressure of 10 MPa. Then, a CR2032 button cell was assembled in a glove box filled with high-purity argon, with the electrode sheet coated as the positive electrode, a 12 mm diameter sodium metal sheet with a thickness of 0.2 mm as the negative electrode, 0.1 mL of 1 mol / L sodium perchlorate / ethylene carbonate / dimethyl carbonate / fluoroethylene carbonate solution as the electrolyte, and a 19 mm diameter polypropylene film as the separator. The battery was charged and discharged on a battery test platform.

[0045] Example 1:

[0046] 1) In a typical synthesis, 5.0 g of zinc chloride was dissolved in a solvent consisting of ethanol (50 mL), water (75 mL), ammonium hydroxide (25-28%, 20 mL), and N,N-dimethylformamide (DMF, 50 mL). Then, 1H-1,2,3-triazole (6.26 mL) was added to the above solution. The whole reaction was stirred at room temperature for 24 h. The white product was filtered, washed with ethanol, and oven-dried at 80 °C for 12 h to obtain a white powder (MET-6).

[0047] 2) The MET-6 powder was transferred to a ceramic pot and heated to 900 °C at a heating rate of 5 °C / min in a tube furnace -1 , and naturally cooled to room temperature after being kept for 3 h under a flowing argon atmosphere. The obtained material was soaked in 3 M hydrochloric acid overnight and washed to remove the residual zinc component. The sample was washed with deionized water and anhydrous ethanol several times and dried in an oven at 60 °C for 24 h. The obtained sample was named NPCF.

[0048] 3) 0.2 g of NPCF obtained in step 2) was dispersed in 80 mL of an 80% ethanol solution, followed by the addition of 1000 mg of SnCl4·5H2O. The dispersion was stirred at 60 °C for 2 h and finally stirred in an oil bath at 120 °C for 8 h to obtain a NPCF / SnO2 composite. Then, 600 mg of the above product was uniformly mixed with sodium hypophosphite at a Sn:P atomic molar ratio of 1:7, and phosphidized by heating to 300 °C at a heating rate of 10 °C / min for 10 min under a nitrogen atmosphere. After washing with water and drying, the target product was obtained and was noted as NPCF@Sn4P3.

[0049] Example 2:

[0050] 1) In a typical synthesis, 5.0 g of zinc chloride was dissolved in a solvent consisting of ethanol (50 mL), water (75 mL), ammonium hydroxide (25-28%, 20 mL), and N,N-dimethylformamide (DMF, 50 mL). Then, 1H-1,2,3-triazole (6.26 mL) was added to the above solution. The whole reaction was stirred at room temperature for 24 h. The white product was filtered, washed with ethanol, and oven-dried at 80 °C for 12 h to obtain a white powder (MET-6).

[0051] 2) The MET-6 powder was transferred to a ceramic pot and heated to 900 °C at a heating rate of 5 °C / min in a tube furnace -1 , and naturally cooled to room temperature after being kept for 3 h under a flowing argon atmosphere. The obtained material was soaked in 3 M hydrochloric acid overnight and washed to remove the residual zinc component. The sample was washed with deionized water and anhydrous ethanol several times and dried in an oven at 60 °C for 24 h. The obtained sample was named NPCF.

[0052] 3) Take 0.1 g of NPCF obtained in step 2) and disperse it in 80 mL of 80% ethanol solution, then add 1000 mg of SnCl4·5H2O, stir and disperse at 60°C for 2 h, and finally stir in an oil bath at 120°C for 8 h to obtain a NPCF / SnO2 composite; then take 600 mg of the above product, mix it uniformly with sodium hypophosphite at a Sn:P ratio of 1:7 (atomic molar ratio), heat it to 300°C at a heating rate of 10°C / min under a nitrogen atmosphere, and keep it at 300°C for 10 min for phosphating treatment. After washing with water and drying, the target product, denoted as NPCF@Sn4P3, is obtained.

[0053] Example 3:

[0054] 1) In a typical synthesis, 5.0 g of zinc chloride was dissolved in a solvent composed of ethanol (50 mL), water (75 mL), ammonium hydroxide (25%-28%, 20 mL), and N,N-dimethylformamide (DMF, 50 mL). Then, 1H-1,2,3-triazole (6.26 mL) was added to the above solution. The entire reaction process was stirred at room temperature for 24 h. The white product obtained was filtered, washed with ethanol, and dried in an oven at 80°C for 12 h to obtain a white powder (MET-6).

[0055] 2) The MET-6 powder was transferred to a ceramic pot and placed in a tube furnace to heat the sample to 900°C at a heating rate of 5°C / min -1 , and kept at 900°C for 3 h under a flowing argon atmosphere, and then naturally cooled to room temperature. The obtained material was soaked in 3M hydrochloric acid overnight and then washed to remove residual zinc components. After washing with deionized water and anhydrous ethanol several times, the sample was dried in an oven at 60°C for 24 h. The obtained sample was named as NPCF.

[0056] 3) Take 0.1 g of NPCF obtained in step 2) and disperse it in 80 mL of 80% ethanol solution, then add 1000 mg of SnCl4·5H2O, stir and disperse at 60°C for 2 h, and finally stir in an oil bath at 120°C for 8 h to obtain a NPCF / SnO2 composite; then take 600 mg of the above product, mix it uniformly with sodium hypophosphite at a Sn:P ratio of 1:7 (atomic molar ratio), heat it to 300°C at a heating rate of 10°C / min under a nitrogen atmosphere, and keep it at 300°C for 10 min for phosphating treatment. After washing with water and drying, the target product, denoted as NPCF@Sn4P3, is obtained.

[0057] Example 4:

[0058] 1) In a typical synthesis, 5.0 g of zinc chloride was dissolved in a solvent consisting of ethanol (50 mL), water (75 mL), ammonium hydroxide (25-28%, 20 mL), and N,N-dimethylformamide (DMF, 50 mL). Then, 1H-1,2,3-triazole (6.26 mL) was added to the above solution. The whole reaction was stirred at room temperature for 24 h. The white product was filtered, washed with ethanol, and oven-dried at 80 °C for 12 h to obtain a white powder (MET-6).

[0059] 2) The MET-6 powder was transferred to a ceramic pot and heated to 900 °C at a heating rate of 5 °C / min in a tube furnace -1 , and then naturally cooled to room temperature under a flowing argon atmosphere for 3 h. The obtained material was soaked in 3 M hydrochloric acid overnight and then washed to remove the residual zinc component. The sample was washed with deionized water and anhydrous ethanol several times and then dried in an oven at 60 °C for 24 h. The obtained sample was named NPCF.

[0060] 3) 0.2 g of NPCF obtained in step 2) was dispersed in 80 mL of an 80% ethanol solution, followed by the addition of 1000 mg of SnCl4·5H2O. The dispersion was stirred at 60 °C for 2 h, and then stirred in an oil bath at 120 °C for 8 h to obtain a NPCF / SnO2 composite. Then, 600 mg of the above product was uniformly mixed with sodium hypophosphite at a Sn:P ratio of 1:7 (atomic molar ratio), and then phosphated by heating to 400 °C at a heating rate of 10 °C / min under a nitrogen atmosphere for 10 min. After washing with water and drying, the target product, denoted as NPCF@Sn4P3, was obtained.

[0061] Comparative Example 1

[0062] With reference to Example 1, the difference is that carbon nanotubes are used instead of NPCF, as follows:

[0063] 0.2 g of carbon nanotubes was dispersed in 80 mL of an 80% ethanol solution, followed by the addition of 1000 mg of SnCl4·5H2O. The dispersion was stirred at 60 °C for 2 h, and then stirred in an oil bath at 120 °C for 8 h to obtain a NPCF / SnO2 composite. Then, 600 mg of the above product was uniformly mixed with sodium hypophosphite at a Sn:P ratio of 1:7 (atomic molar ratio), and then phosphated by heating to 300 °C at a heating rate of 10 °C / min under a nitrogen atmosphere for 10 min. After washing with water and drying, the comparative composite material was obtained.

[0064] Comparative Example 2

[0065] With reference to Example 1, the difference is that graphene oxide is used instead of NPCF, as follows:

[0066] Take 0.2 g of graphene oxide and disperse it in 80 mL of 80% ethanol solution, then add 1000 mg of SnCl4·5H2O, stir and disperse at 60°C for 2 h, and finally stir in an oil bath at 120°C for 8 h to obtain the NPCF / SnO2 composite; then take 600 mg of the above product, mix it with sodium hypophosphite at a ratio of Sn:P=1:7 (atomic molar ratio), grind uniformly, heat to 300°C at a heating rate of 10°C / min under nitrogen atmosphere, and phosphorize for 10 min, and then wash with water and dry to obtain the comparative composite material.

[0067] Comparative Example 3

[0068] Referring to Example 1, the difference is that the mass ratio of the NPCF to the tin source is 1:4, and the specific process is as follows:

[0069] Take 0.2 g of the NPCF prepared in Example 1 and disperse it in 80 mL of 80% ethanol solution, then add 800 mg of SnCl4·5H2O, stir and disperse at 60°C for 2 h, and finally stir in an oil bath at 120°C for 8 h to obtain the NPCF / SnO2 composite; then take 600 mg of the above product, mix it with sodium hypophosphite at a ratio of Sn:P=1:7 (atomic molar ratio), grind uniformly, heat to 300°C at a heating rate of 10°C / min under nitrogen atmosphere, and phosphorize for 10 min, and then wash with water and dry to obtain the comparative composite material.

[0070] Performance detection

[0071] The materials prepared in the examples and comparative examples were respectively made into lithium batteries and subjected to charge-discharge test, and the results are shown in Table 1 and Figure 1 、 Figure 2 、 Figure 3 .

[0072] Table 1 Performance test results

[0073]

[0074] As can be seen from Table 1, the overall performance of Examples 1-4 is better, and the first circle capacity, rate performance, and capacity retention rate of the examples are all more advantageous compared to the comparative examples, which indicates that the DPCN catalyzes the conversion reaction of the phosphorized tin during the charge-discharge process, and promotes the improvement of the electrochemical performance.

[0075] The material prepared in Example 1 was made into a sodium battery and subjected to rate performance test, and the discharge capacity was respectively measured at 100 mA·g -1 , 200 mA·g -1 , 500 mA·g -1 , 1000 mA·g -1 , 2000 mA·g -1The results of the rate test at different current densities are shown in Table 1 Figure 4 From Table 1, it can be seen that the material has good rate performance. Figure 4 From Table 1, it can be seen that the material has good rate performance.

[0076] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details described in the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0077] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again by the present application.

[0078] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A method for preparing a porous carbon supported tin phosphide composite material, characterized in that: The method comprises the following steps: (1) obtaining a metal organic ligand MET-6; (2) placing the MET-6 into a tube furnace, washing and drying the calcined product under the protection of inert gas to obtain a carbon nitride carrier NPCF; (3) mixing the NPCF with a tin source and a solvent, and then heating, wherein the mass ratio of the NPCF to the tin source is 1:5-9, to obtain an NPCF / SnO2 composite; mixing the NPCF / SnO2 composite with a phosphorus source according to a certain proportion, and then calcining under the protection of inert gas to obtain a final product NPCF@Sn4P3.

2. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 1, characterized in that: The preparation method of the metal organic ligand MET-6 in step (1) comprises: dissolving a zinc salt and 1H-1,2,3-triazole in a solvent composed of ethanol, water, ammonium hydroxide and N,N-dimethylformamide according to a proportion, and reacting at room temperature for a period of time to generate the metal organic ligand MET-6.

3. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 2, characterized in that: The zinc salt is one of zinc chloride, zinc nitrate, zinc acetate and acetylacetone zinc.

4. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 3, characterized in that: In step (1), the proportion of the zinc salt to 1H-1,2,3-triazole is 3-10 g: 5-10 mL.

5. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 3, characterized in that: In step (1), the reaction time is 12-48 h.

6. The method for preparing the porous carbon supported tin phosphide composite material according to any one of claims 1-5, characterized in that: The inert gas in step (2) is nitrogen or argon.

7. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 6, characterized in that: The calcination temperature in step (2) is 700-1000 ℃.

8. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 7, characterized in that: The calcination temperature in step (2) is 800-900 ℃.

9. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 6, characterized in that: The calcination time in step (2) is 1-10 h.

10. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 9, characterized in that: The calcination time in step (2) is 2-5 h.

11. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 6, characterized in that: The washing in step (2) comprises soaking washing with an acid washing solution, deionized water washing and ethanol washing, and drying at 50-100 ℃ for 10-20 h after washing.

12. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 1, characterized in that: The mass ratio of the NPCF to the tin source in step (3) is 1:5-6.

13. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 12, characterized in that: The atomic molar ratio of Sn in the tin source to P in the phosphorus source is 1:5-15.

14. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 13, characterized in that: The atomic molar ratio of Sn in the tin source to P in the phosphorus source is 1:7-9.

15. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 12, characterized in that: The solvent in step (3) is an alcohol solution.

16. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 15, characterized in that: The solvent in step (3) is any one of ethanol, propanol and butanol.

17. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 15, characterized in that: The heating temperature in step (3) is 100-200 ℃.

18. The method of claim 17, wherein the porous carbon supported tin phosphide composite is prepared by: The heating temperature in step (3) is 120-150 ℃.

19. The method of claim 15, wherein the porous carbon supported tin phosphide composite is prepared by: The heating time in step (3) is 5-20 h.

20. The method of claim 19, wherein the porous carbon supported tin phosphide composite is prepared by: The heating time in step (3) is 8-12 h.

21. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 15, characterized in that: The inert gas in step (3) is nitrogen or argon.

22. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 15, characterized in that: The calcination temperature in step (3) is 200-400 ℃.

23. The method of claim 22, wherein the porous carbon supported tin phosphide composite is prepared by: The calcination temperature in step (3) is 250-350 ℃.

24. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 15, characterized in that: The calcination time in step (3) is 1-30 min.

25. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 24, characterized in that: The calcination time in step (3) is 10-20 min.

26. The method for preparing the porous carbon-supported tin phosphide composite material according to claim 1, characterized in that: The composite material is a porous carbon nitride as a porous carrier, and the pore channel is embedded with Sn4P3.

Images