Silicon air battery with silicon conductive metal organic framework composite and preparation method

Abstract

The application provides a silicon conductive metal organic framework composite silicon air battery and a preparation method, the application Co3(HITP)2 is used as an intrinsic conductive pi-d conjugated two-dimensional conductive MOF, has a good porous network, and the Co3(HITP)2 has higher electrical conductivity. The porous structure and the high electrical conductivity characteristics can effectively improve the performance of the silicon air battery. Compared with a Si anode and a Si@Co3(HITP)2 composite anode, the electrical conductivity of the Si@Co3(HITP)2 composite is about one order of magnitude higher than that of the Si. The conductive MOF is combined with the silicon wafer by a coating method to obtain a composite anode of the silicon air battery. In the combination process, the thickness of the Co3(HITP)2 coating can be effectively controlled by controlling the distance between the scraper and the silicon wafer.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a silicon-conductive metal-organic framework composite silicon-air battery and its manufacturing method. Background Technology

[0002] In an air battery, the anode is located inside the battery, and the air cathode is in close contact with the inside of the battery casing. Moreover, the active material of the cathode comes from oxygen in the air, so the air electrode occupies very little space in the battery. Therefore, with the same volume and weight, an air battery can hold more negative electrode reactants, thus having a higher capacity compared to a traditional battery.

[0003] Metal-air batteries possess high energy density, and currently, the main types include lithium-air batteries, magnesium-air batteries, aluminum-air batteries, and zinc-air batteries. However, all of these metal-air batteries still have some unresolved issues, such as dendrite formation during discharge causing short circuits, and corrosion of the metal anode and slow oxygen reduction reactions leading to low coulombic efficiency. Compared to metal-air batteries, research on silicon-air batteries using semiconductor silicon as the anode is still in its early stages.

[0004] Silicon, as one of the most abundant elements on Earth, has a wide range of raw material sources and boasts high energy density, making its advantages as an electrode material obvious. Furthermore, silicon-air batteries offer advantages such as low cost and environmental friendliness. The passivation and corrosion rate of the silicon anode in a silicon-air battery directly impacts the battery's performance. Simultaneously, silicon, as a semiconductor material, has lower conductivity than metallic materials. Therefore, finding a method to protect the silicon anode to reduce passivation and corrosion while improving its conductivity is crucial.

[0005] Metal-organic frameworks (MOFs) are coordination polymers that use inorganic metal ions or metal clusters as bonding points and organic ligands as connecting bridges. They possess characteristics such as corrosion resistance, large specific surface area, permanent porosity, tunable pore size, and customizable functionality. However, the poor conductivity of MOFs limits their application in energy storage. To address the low conductivity of MOFs, conductive MOFs have been developed based on MOFs, exhibiting significantly improved conductivity compared to traditional MOFs.

[0006] Therefore, conductive MOFs are expected to play a role in improving the efficiency of silicon-air batteries. Currently, conductive MOFs are already used in lithium-ion and potassium-ion batteries, and their excellent conductivity, large specific area, and porous structure have made significant contributions to improving battery performance. How to combine conductive MOFs with silicon anodes to effectively improve the performance of silicon-air batteries has become an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to provide a silicon-conductive metal-organic framework composite silicon-air battery and its preparation method. By utilizing its porous structure and high conductivity, the performance of silicon-air batteries can be effectively improved.

[0008] According to one objective of the present invention, the present invention provides a method for preparing a silicon-air battery using a silicon conductive metal-organic framework composite material, comprising the following steps:

[0009] 1. Preparation of conductive metal-organic framework materials

[0010] 101) 2,3,6,7,10,11-hexaaminotriphenylhexahydrochloride (HITP·6HCl) and anhydrous cobalt chloride (CoCl2) were separately dispersed in aqueous solutions, and the two solutions were mixed to carry out the reaction.

[0011] 102) Add ammonia water dropwise to the mixed solution obtained in step 1) to promote the reaction. The reaction conditions are 16-25℃ for 3-4 hours. After the reaction is completed, wash with water and ethanol 3-5 times. Finally, dry under vacuum at 60-80℃ for 18-24 hours to obtain Co3(HITP)2 powder.

[0012] 2. Preparation of silicon-conductive metal-organic framework composite anode

[0013] The conductive MOF powder and polyvinylidene fluoride powder are mixed and ground in a mortar to make them uniformly mixed. Then the mixture is dissolved in N-methylpyrrolidone solution. The mixed solution is coated onto the surface of a silicon wafer using a scraper. The silicon wafer is then dried in a vacuum oven to obtain the silicon-conductive metal-organic framework composite anode.

[0014] 3. Preparation of Pt / C catalyst air cathode

[0015] Place the Pt / C catalyst in a beaker, add Nafion solution and isopropanol to the beaker in sequence, ultrasonically disperse the mixed solution to make a slurry, then coat the slurry on the surface of carbon cloth and let it air dry to obtain an air cathode.

[0016] 4. Silicon-air battery assembly

[0017] From left to right, place the anode shell, copper sheet, silicon-conductive metal-organic framework composite material, electrolyte shell, air cathode, copper sheet, and cathode shell in sequence, and finally fix them with screws to complete the assembly of the silicon-air battery.

[0018] Further, in step 101), the concentration of the HITP·6HCl aqueous solution is 1.6 × 10⁻⁶. -3 ~2.0×10 -3 The concentration of the CoCl2 aqueous solution was 2.8 × 10 mol / L. -2~3.2×10 -2 mol / L.

[0019] Further, in step 102), the concentration of ammonia water is 14 mol / L, and the volume ratio of ammonia water to the mixed solution is 1:20 to 1:25.

[0020] Further, in step 2, the conductive MOF is Co3(HITP)2, and the mass of a single silicon wafer used is 1-20 mg; the amount of polyvinylidene fluoride powder used is 0.1-15 mg, which acts as a binder, and the mass ratio of Co3(HITP)2 to polyvinylidene fluoride is 1-10; the amount of N-methylpyrrolidone solution used is 10-200 μL; the coating thickness is 1-30 μm; the particle size of Co3(HITP)2 on the coating is 3-100 nm; the temperature of the vacuum oven is 60-80 °C, and the drying time is 6-24 h.

[0021] Further, in step 3, the amount of Pt / C catalyst used is 1-6 mg; the amount of Nafion solution used is 200-1200 μL; and the amount of isopropanol solution used is 100-800 μL.

[0022] Furthermore, in step 4, the copper sheet serves to conduct electricity, facilitating connection to external testing equipment; the electrolyte tank has a capacity of 1–30 mL; and the electrolyte used is KOH with a concentration of 1–6 mol / L.

[0023] According to another objective of the present invention, the present invention provides a silicon-conductive metal-organic framework composite silicon-air battery, which is prepared by the above method.

[0024] Beneficial effects

[0025] This invention utilizes Co3(HITP)2, an intrinsically conductive π-d conjugate two-dimensional conductive MOF, which possesses a well-developed porous network and high electrical conductivity. By leveraging its porous structure and high conductivity, the performance of silicon-air batteries can be effectively improved. Compared to Si@Co3(HITP)2 composite anodes, the Si@Co3(HITP)2 composite anode exhibits approximately an order of magnitude higher conductivity. The composite anode for silicon-air batteries is obtained by coating the conductive MOF with a silicon wafer. During the coating process, the thickness of the Co3(HITP)2 coating can be effectively controlled by adjusting the distance between the squeegee and the silicon wafer. Attached Figure Description

[0026] Figure 1 XPS image of Co3(HITP)2 according to an embodiment of the present invention;

[0027] Figure 2Here is a planar SEM image of the silicon conductive metal-organic framework composite material prepared in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of a silicon-air battery prepared according to an embodiment of the present invention;

[0029] Figure 4 In this embodiment of the invention, the current density is 0.03 mA / cm². 2 A comparison of the discharge times of a Si@Co3(HITP)2 air battery synthesized with Co3(HITP)2 and polyvinylidene fluoride in a ratio of 8:2 and a blank silicon air battery.

[0030] Figure 5 In this embodiment of the invention, the current density is 0.03 mA / cm². 2 The graph shows a comparison of the discharge times of a Si@Co3(HITP)2 air battery synthesized with a Co3(HITP)2 and polyvinylidene fluoride ratio of 9:1 and a blank silicon air battery. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Example 1

[0035] A method for preparing a silicon-conductive metal-organic framework composite silicon-air battery includes the following steps:

[0036] 1. Preparation of conductive metal-organic framework materials

[0037] 1) 2,3,6,7,10,11-hexaaminotriphenylhexahydrochloride (HITP·6HCl) and anhydrous cobalt chloride (CoCl2) were separately dispersed in aqueous solutions, and the two solutions were mixed for reaction; the concentration of the HITP·6HCl aqueous solution was 1.6 × 10⁻⁶. 3 ~2.0×10 -3 The concentration of the CoCl2 aqueous solution was 2.8 × 10 mol / L. -2 ~3.2×10 -2 mol / L.

[0038] 2) Add ammonia water dropwise to the mixed solution obtained in step 1) to promote the reaction. The reaction conditions are 16-25℃ for 3-4 hours. After the reaction is completed, wash with water and ethanol 3-5 times. Finally, dry under vacuum at 60-80℃ for 18-24 hours to obtain Co3(HITP)2 powder. The concentration of ammonia water is 14mol / L, and the volume ratio of ammonia water to the mixed solution is 1:20-1:25.

[0039] 3) Place the silicon wafer in methanol and anhydrous ethanol in sequence for ultrasonic cleaning for 5-10 minutes to remove oil and organic matter from its surface.

[0040] 4) After rinsing the silicon wafers processed in step 3) with water, immerse them in a solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 3:1 for 1 to 2 hours.

[0041] 5) After rinsing the silicon wafers processed in step 4) with water, immerse them in a solution of hydrofluoric acid and deionized water at a ratio of 1:3 (volume ratio) for 5-10 minutes to remove the oxide layer.

[0042] 6) After rinsing the silicon wafer processed in step 5) with water, repeat step 3) to obtain a clean silicon wafer ready for use.

[0043] 7) After mixing conductive MOF powder and polyvinylidene fluoride powder, grind them in a mortar to make them uniformly mixed. Then, dissolve the mixture in N-methylpyrrolidone solution. Coat the mixed solution onto the surface of a silicon wafer using a doctor blade. Then, dry the silicon wafer in a vacuum oven to obtain silicon-conductive metal-organic framework composite material.

[0044] The conductive MOF is Co3(HITP)2, and the mass of a single silicon wafer is 1-20 mg.

[0045] The amount of polyvinylidene fluoride powder used is 0.1-15 mg, and its function is as a binder. The mass ratio of Co3(HITP)2 to polyvinylidene fluoride is 1-10.

[0046] The volume of N-methylpyrrolidone solution used is 10–200 μL;

[0047] The coating thickness is 1–30 μm;

[0048] The Co3(HITP)2 particles on the coating have a size of 3–100 nm;

[0049] The vacuum oven temperature is 60–80℃, and the drying time is 6–24 hours;

[0050] Silicon wafer dimensions: thickness 100–800 μm, diameter 10–80 mm. They can be arsenic-doped, phosphorus-doped, or boron-doped silicon wafers.

[0051] The silicon-air battery composite anode material prepared by the method described above.

[0052] 2. Cathode material preparation

[0053] The method for preparing a Pt / C catalyst air cathode includes the following steps:

[0054] Place the Pt / C catalyst in a beaker, add Nafion solution and isopropanol to the beaker in sequence, ultrasonically disperse the mixed solution to make a slurry, and then coat the slurry on the surface of carbon cloth and let it air dry to obtain an air cathode.

[0055] The amount of Pt / C catalyst used is 1–6 mg;

[0056] The volume of Nafion solution used is 200–1200 μL;

[0057] The volume of isopropanol solution used is 100–800 μL.

[0058] 3. Battery assembly

[0059] Silicon-air battery assembly includes the following steps:

[0060] From left to right, place the anode shell, copper sheet, silicon-conductive metal-organic framework composite material, electrolyte shell, air cathode, copper sheet, and cathode shell in sequence, and finally fix them with screws to complete the assembly of the silicon-air battery.

[0061] The copper sheet serves to conduct electricity, facilitating the connection of external testing equipment.

[0062] The electrolyte tank capacity is 1–30 mL;

[0063] The electrolyte is KOH with a concentration of 1–6 mol / L.

[0064] Example 2

[0065] A method for preparing a silicon-conductive metal-organic framework composite silicon-air battery includes the following steps:

[0066] 1. Preparation of conductive metal-organic framework materials

[0067] 1) 2,3,6,7,10,11-hexaaminotriphenylhexahydrochloride (HITP·6HCl) and anhydrous cobalt chloride (CoCl2) were separately dispersed in aqueous solutions, and the two solutions were mixed for reaction; the concentration of the HITP·6HCl aqueous solution was 1.86 × 10⁻⁶. -3 The concentration of the CoCl2 aqueous solution was 3.08 × 10 mol / L. -2 mol / L.

[0068] 2) Add ammonia water dropwise to the mixed solution obtained in step 1) to promote the reaction. The reaction conditions are 16℃ for 3h. After the reaction is completed, wash with water and ethanol 3 times. Finally, dry under vacuum at 60℃ for 18h to obtain Co3(HITP)2 powder. The concentration of ammonia water is 14mol / L and the volume ratio of ammonia water to the mixed solution is 1:25.

[0069] 3) Place the silicon wafer in methanol and anhydrous ethanol in sequence for ultrasonic cleaning for 5 minutes to remove oil and organic matter from its surface.

[0070] 4) After rinsing the silicon wafers processed in step 3) with water, immerse them in a solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 3:1 for 2 hours.

[0071] 5) After rinsing the silicon wafers processed in step 4) with water, immerse them in a solution of hydrofluoric acid and deionized water at a ratio of 1:3 (volume ratio) for 5 minutes to remove the oxide layer.

[0072] 6) After rinsing the silicon wafer processed in step 5) with water, repeat step 3) to obtain a clean silicon wafer ready for use.

[0073] 7) After mixing conductive MOF powder and polyvinylidene fluoride powder, grind them in a mortar to make them uniformly mixed. Then, dissolve the mixture in N-methylpyrrolidone solution. Coat the mixed solution onto the surface of a silicon wafer using a doctor blade. Then, dry the silicon wafer in a vacuum oven to obtain silicon-conductive metal-organic framework composite material.

[0074] The conductive MOF is Co3(HITP)2, and the mass of a single silicon wafer is 2mg.

[0075] The amount of polyvinylidene fluoride powder used is 0.5 mg, and its function is as a binder. The mass ratio of Co3(HITP)2 to polyvinylidene fluoride is 8:2.

[0076] The volume of N-methylpyrrolidone solution used was 20 μL;

[0077] The coating thickness is 5μm;

[0078] The vacuum oven temperature is 60℃, and the drying time is 10 hours;

[0079] Silicon wafer dimensions: 500μm thick, 40mm in diameter. It is a phosphorus-doped silicon wafer.

[0080] The silicon-air battery composite anode material prepared by the method described above.

[0081] 2. Cathode material preparation

[0082] The method for preparing a Pt / C catalyst air cathode includes the following steps:

[0083] Place the Pt / C catalyst in a beaker, add Nafion solution and isopropanol to the beaker in sequence, ultrasonically disperse the mixed solution to make a slurry, and then coat the slurry on the surface of carbon cloth and let it air dry to obtain an air cathode.

[0084] The amount of Pt / C catalyst used is 2.8 mg;

[0085] The volume of the Nafion solution used was 700 μL;

[0086] The volume of the isopropanol solution used is 300 μL.

[0087] 3. Battery assembly

[0088] Silicon-air battery assembly includes the following steps:

[0089] From left to right, arrange the anode shell, copper sheet, silicon-conductive metal-organic framework composite material, electrolyte shell, air cathode, copper sheet, and cathode shell in that order, and finally secure them with screws. This completes the assembly of the silicon-air battery. Figure 3 As shown.

[0090] The copper sheet serves to conduct electricity, facilitating the connection of external testing equipment.

[0091] The electrolyte tank capacity is 12.1 mL;

[0092] The electrolyte used is KOH with a concentration of 6 mol / L.

[0093] like Figure 1 As shown, Figure 1 XPS plot of Co3(HITP)2 Figure 2 This is a planar SEM image of the silicon-conductive metal-organic framework composite material prepared in this embodiment. Figure 1 As shown, XPS analysis reveals the coordination environment of Co, thus proving the synthesis of Co3(HITP)2. Figure 2 As shown, the surface of the silicon-conductive metal-organic framework composite material exhibits numerous porous structures. The conductivity of bare silicon, measured using a four-probe array, is 5.16 × 10⁻⁶. -3 The conductivity of the silicon-conductive metal-organic framework composite material is 5.24 × 10⁻⁶ S / m. -2 With a current of S / m, its conductivity is increased by approximately one order of magnitude. Figure 4 To achieve a current density of 0.03 mA / cm² 2 The comparison of discharge times between Si@Co3(HITP)2 air batteries and blank silicon air batteries shows that the discharge time of the Si@Co3(HITP)2 composite anode is significantly improved compared with that of the blank silicon wafer anode.

[0094] Example 3

[0095] A method for preparing a silicon-conductive metal-organic framework composite silicon-air battery includes the following steps:

[0096] 1. Preparation of conductive metal-organic framework materials

[0097] 1) 2,3,6,7,10,11-hexaaminotriphenylhexahydrochloride (HITP·6HCl) and anhydrous cobalt chloride (CoCl2) were separately dispersed in aqueous solutions, and the two solutions were mixed for reaction; the concentration of the HITP·6HCl aqueous solution was 1.86 × 10⁻⁶. -3 The concentration of the CoCl2 aqueous solution was 3.08 × 10 mol / L. -2 mol / L.

[0098] 2) Add ammonia water dropwise to the mixed solution obtained in step 1) to promote the reaction. The reaction conditions are 16℃ for 3h. After the reaction is completed, wash with water and ethanol 3 times. Finally, dry under vacuum at 60℃ for 18h to obtain Co3(HITP)2 powder. The concentration of ammonia water is 14mol / L and the volume ratio of ammonia water to the mixed solution is 1:25.

[0099] 3) Place the silicon wafer in methanol and anhydrous ethanol in sequence for ultrasonic cleaning for 5 minutes to remove oil and organic matter from its surface.

[0100] 4) After rinsing the silicon wafers processed in step 3) with water, immerse them in a solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 3:1 for 2 hours.

[0101] 5) After rinsing the silicon wafers processed in step 4) with water, immerse them in a solution of hydrofluoric acid and deionized water at a ratio of 1:3 (volume ratio) for 5 minutes to remove the oxide layer.

[0102] 6) After rinsing the silicon wafer processed in step 5) with water, repeat step 3) to obtain a clean silicon wafer ready for use.

[0103] 7) After mixing conductive MOF powder and polyvinylidene fluoride powder, grind them in a mortar to make them uniformly mixed. Then, dissolve the mixture in N-methylpyrrolidone solution. Coat the mixed solution onto the surface of a silicon wafer using a doctor blade. Then, dry the silicon wafer in a vacuum oven to obtain silicon-conductive metal-organic framework composite material.

[0104] The conductive MOF is Co3(HITP)2, and the mass of a single silicon wafer is 2mg.

[0105] The amount of polyvinylidene fluoride powder used is 0.22 mg, and its function is as a binder. The mass ratio of Co3(HITP)2 to polyvinylidene fluoride is 9:1.

[0106] The volume of N-methylpyrrolidone solution used was 20 μL;

[0107] The coating thickness is 5μm;

[0108] The vacuum oven temperature is 60℃, and the drying time is 10 hours;

[0109] Silicon wafer dimensions: 500μm thick, 40mm in diameter. It is a phosphorus-doped silicon wafer.

[0110] The silicon-air battery composite anode material prepared by the method described above.

[0111] 2. Cathode material preparation

[0112] The method for preparing a Pt / C catalyst air cathode includes the following steps:

[0113] Place the Pt / C catalyst in a beaker, add Nafion solution and isopropanol to the beaker in sequence, ultrasonically disperse the mixed solution to make a slurry, and then coat the slurry on the surface of carbon cloth and let it air dry to obtain an air cathode.

[0114] The amount of Pt / C catalyst used is 2.8 mg;

[0115] The volume of the Nafion solution used was 700 μL;

[0116] The volume of the isopropanol solution used is 300 μL.

[0117] 3. Battery assembly

[0118] Silicon-air battery assembly includes the following steps:

[0119] From left to right, arrange the anode shell, copper sheet, silicon-conductive metal-organic framework composite material, electrolyte shell, air cathode, copper sheet, and cathode shell in that order, and finally secure them with screws. This completes the assembly of the silicon-air battery (e.g., ...). Figure 3 (As shown).

[0120] The copper sheet serves to conduct electricity, facilitating the connection of external testing equipment.

[0121] The electrolyte tank has a capacity of 12.1 mL;

[0122] The electrolyte used is KOH with a concentration of 6 mol / L.

[0123] Figure 5 The current density is 0.03 mA / cm². 2 The comparison chart of discharge time between Si@Co3(HITP)2 air battery and blank silicon air battery shows that there is no significant difference in voltage between the Si@Co3(HITP)2 composite anode and the blank silicon wafer anode, but the discharge time of the battery assembled with the Si@Co3(HITP)2 composite anode is significantly improved.

[0124] This invention addresses the limitation of most existing MOFs in battery applications due to their poor conductivity. Co3(HITP)2, an intrinsically conductive π-d conjugate two-dimensional conductive MOF, possesses a well-developed porous network and exhibits high conductivity. Utilizing its porous structure and high conductivity, the performance of silicon-air batteries can be effectively improved. Compared to Si@Co3(HITP)2 composite anodes, the conductivity of the Si@Co3(HITP)2 composite anode is approximately an order of magnitude higher.

[0125] This invention utilizes a coating method to composite a conductive MOF with a silicon wafer to obtain a composite anode for silicon-air batteries. During the composite process, the thickness of the Co3(HITP)2 coating can be effectively controlled by adjusting the distance between the scraper and the silicon wafer.

[0126] This invention controls the amount of Co3(HITP)2 on a silicon wafer by controlling the mass ratio of Co3(HITP)2 to polyvinylidene fluoride.

[0127] Examples in this invention show that a silicon-air battery assembled with a Si@Co3(HITP)2 composite anode achieves a speed of 0.03 mA / cm². 2 At a current density of [insert current density here], it can sustain discharge for nearly 480 hours, a significant improvement in discharge time compared to silicon-air batteries assembled with Si anodes. The method provided by this invention is simple, reliable, and suitable for large-scale industrial production.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a silicon-conductive metal-organic framework composite silicon-air battery, characterized in that, Includes the following steps:

1. Preparation of conductive metal-organic framework materials 101) 2,3,6,7,10,11-hexaaminotriphenylhexahydrochloride (HITP·6HCl) and anhydrous cobalt chloride (CoCl2) were separately dispersed in aqueous solutions, and the two solutions were mixed for reaction; the concentration of the HITP·6HCl aqueous solution was 1.6 × 10⁻⁶. -3 ~2.0 × 10 -3 The concentration of the CoCl2 aqueous solution was 2.8 × 10 mol / L. -2 ~ 3.2 × 10 -2 mol / L; 102) Add ammonia water dropwise to the mixed solution obtained in step 1) to promote the reaction. The reaction conditions are 16-25 °C for 3-4 h. After the reaction is complete, wash with water and ethanol 3-5 times. Finally, dry under vacuum at 60-80 °C for 18-24 h to obtain Co3(HITP)2 powder. The concentration of ammonia water is 14 mol / L, and the volume ratio of ammonia water to the mixed solution is 1:20-1:

25.

2. Preparation of silicon-conductive metal-organic framework composite anode The conductive MOF powder and polyvinylidene fluoride powder are mixed and ground in a mortar to make them uniformly mixed. Then the mixture is dissolved in N-methylpyrrolidone solution. The mixed solution is coated onto the surface of a silicon wafer using a scraper. The silicon wafer is then dried in a vacuum oven to obtain the silicon-conductive metal-organic framework composite anode. The conductive MOF is Co3(HITP)2, with a mass of 1-20 mg per silicon wafer; the polyvinylidene fluoride powder is used in an amount of 0.1-15 mg, serving as a binder, with a mass ratio of Co3(HITP)2 to polyvinylidene fluoride of 1-10; the N-methylpyrrolidone solution is used in an amount of 10-200 μL; the coating thickness is 1-30 μm; the Co3(HITP)2 particle size on the coating is 3-100 nm; the vacuum oven temperature is 60-80 ℃, and the drying time is 6-24 h.

3. Preparation of Pt / C catalyst air cathode Place the Pt / C catalyst in a beaker, add Nafion solution and isopropanol to the beaker in sequence, ultrasonically disperse the mixed solution to make a slurry, then coat the slurry on the surface of carbon cloth and let it air dry to obtain an air cathode. The amount of Pt / C catalyst used is 1 ~ 6 mg; the amount of Nafion solution used is 200 ~ 1200 μL; the amount of isopropanol solution used is 100 ~ 800 μL; 4. Silicon-air battery assembly From left to right, place the anode shell, copper sheet, silicon-conductive metal-organic framework composite material, electrolyte shell, air cathode, copper sheet, and cathode shell in sequence, and finally fix them with screws to complete the assembly of the silicon-air battery.

2. The method for preparing a silicon-air battery using a silicon conductive metal-organic framework composite material according to claim 1, characterized in that, In step 4, the copper sheet serves to conduct electricity, facilitating connection to external testing equipment; the electrolyte tank has a capacity of 1 to 30 mL; and the electrolyte used is KOH with a concentration of 1 to 6 mol / L.

3. A silicon-conductive metal-organic framework composite silicon-air battery, characterized in that, The silicon-air battery is prepared according to the method described in any one of claims 1-2.

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