A porous carbon composite material, a preparation method and application thereof

Abstract

The application provides a porous carbon composite material and a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing a coordination agent A, at least one A(OR1)4 and a solvent A, and heating to obtain a mixed solution A; mixing the coordination agent A, at least one B(OR2)5 and a solvent B, and heating to obtain a mixed solution B; (2) mixing the mixed solution A and the mixed solution B, adding a node agent solution into the mixed solution A and the mixed solution B, and reacting to obtain a reaction solution; (3) drying and solidifying the reaction solution obtained in the step (2) to obtain a porous nanorod; and (4) crushing the porous nanorod, calcining, depositing carbon, and obtaining the porous carbon composite material. The metal polymer method is used to prepare the porous carbon composite material without removing the template and with excellent performance by using a transition metal oxide as a template agent, and the transition metal oxide is used as the template agent to improve the electrochemical performance of the porous carbon composite material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of carbon materials, and particularly relates to a porous carbon composite material and a preparation method and application thereof. BACKGROUND

[0002] Nowadays, porous carbon materials play an irreplaceable role in the fields of catalysis, adsorption, gas storage, etc. The rich pore structure, large specific surface area and low cost of the porous carbon materials are the main reasons why they have advantages in various fields. However, the above industries do not have very fine requirements for the pore structure of the porous carbon, so the porous carbon materials have a high production capacity, but lack the technical reserves for fine control of the pore structure. With the rapid development of the energy industry, the preparation of multi-mesoporous carbon with pores of 1nm to 20nm is considered to be a crucial step to help the silicon-carbon negative electrode to break through the existing performance. For this reason, researchers at home and abroad have invested a lot of effort to study the preparation method of multi-mesoporous carbon.

[0003] The preparation method of multi-mesoporous carbon often tends to use etching or activation methods to produce pores on the surface and inside of the carbon material. "Highly thermal conductive metal / carbon composites by pulsed electric current sintering [J]. Synthetic Metals, 2009, 159(21-22): 2170-2172." prepared an activated carbon material with a large specific surface area (2150m 2 ·g -1 ) and high micropore content (1.17cm 3 ·g -1 ) by KOH activation. Various templates with specific morphologies can also be coated or deposited to obtain porous carbon materials. For example, the document "Munoz-Torrico M, Salazar M A, Millán, Miriam de Jesús Mohedano, et al. Eligibility for the shorter regimen for multidrug-resistant tuberculosis in Mexico [J]. European Respiratory Journal, 2018, 51(3): 1702267." prepared hollow nanocarbon spheres by using a soft template method, and the specific surface area of the hollow nanocarbon spheres was 1129.8m 2 ·g -1 , and the pore size distribution was 1nm to 2nm.

[0004] The prior art commonly uses a preparation method of a reverse template to prepare a porous carbon material, but the preparation method of the reverse template uses a reverse template agent which is often not conducive to the final performance of the product and needs to be removed or converted additionally. Therefore, how to provide a new preparation method without using a reverse template agent to prepare a porous carbon material with excellent performance has become a technical problem to be solved at present. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a porous carbon composite material and a preparation method and application thereof. The present application uses a metal polymer method to prepare a porous carbon composite material with excellent performance by using a transition metal oxide as a template agent.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a preparation method of a porous carbon composite material, which comprises the following steps:

[0008] (1) mixing a coordination agent A, at least one A(OR1)4 and a solvent A, heating to obtain a mixed solution A;

[0009] mixing the coordination agent A, at least one B(OR2)5 and a solvent B, heating to obtain a mixed solution B;

[0010] wherein A represents an element of group IVB and B represents an element of group VB;

[0011] R1 and R2 each independently represent a C1-C5 alkyl group;

[0012] (2) mixing the mixed solution A and the mixed solution B, adding a node agent solution thereto, and reacting to obtain a reaction solution;

[0013] (3) drying and solidifying the reaction solution obtained in step (2) to obtain a porous nanorod;

[0014] (4) crushing and calcining the porous nanorod, depositing carbon to obtain a porous carbon composite material.

[0015] In the present application, the porous carbon composite material comprises a transition metal oxide template agent and a porous carbon material.

[0016] In the present application, the metal polymer method is used to prepare a porous carbon composite material with excellent performance without removing the template by using a transition metal oxide as a template agent, and the transition metal oxide as a template agent can increase the electrochemical performance of the material. At the same time, the transition metal oxide can be removed by acid washing to obtain a low-density porous carbon material.

[0017] In the present application, by using the node agent, the crystal growth behavior and site of the transition metal oxide template are controlled, and the pore size and particle size of the porous carbon composite material are effectively controlled.

[0018] In the present application, R1 and R2 each independently represent C1-C5 (for example, can be C1, C2, C3, C4 or C5) alkyl.

[0019] In step (1) of the present application, by using a specific complexing agent, A(OR1)4, B(OR2)5 is stabilized, and at the same time, part of the functional groups (-OR1, OR2) in A(OR1)4, B(OR2)5 can be consumed, so that the reaction proceeds in the designed direction.

[0020] Taking acetylacetone (Hacac) as a complexing agent, step (1) involves the following reaction:

[0021] A(OR1)4+n Hacac→A(OR1) 4-n (acac) n +n R1OH Formula 1;

[0022] B(OR2)5+m Hacac→B(OR2) 5-m (acac) m +m R2OH Formula 2;

[0023] Wherein, n is a positive integer of 1-4 (for example, can be 1, 2, 3 or 4), and m is a positive integer of 1-5 (for example, can be 1, 2, 3, 4 or 5).

[0024] In step (2) of the present application, during the reaction process, it is beneficial to the uniform dispersion of metal elements at the atomic level, reduces the subsequent sintering temperature, and also ensures the stability of the material. The node agent is used to intentionally control the morphology of the reaction product. After the synthesis of the conventional metal polymer precursor, the particle size is too large, the particle size is not uniform, and the morphology is irregular. After adding the node agent, the product occurs self-assembly locally, so that the material morphology is regular, and the product of nanoscale can be obtained. The water in the node agent mixed solution is added to the reaction as a catalyst for the reaction, to promote the occurrence of the reaction, and finally the reactant is a clear and uniform liquid.

[0025] The reaction involved in step (2) is as follows:

[0026] …A-OR1+H2O→…A-OH+R1OH Formula 3-1;

[0027] …B-OR2+H2O→…B-OH+R2OH Formula 3-2;

[0028] …A-OH+…B-OH→…A-O-B…+H2O Formula 4;

[0029] …A-OR1+…B-OH→…A-O-B…+R1OH Formula 5;

[0030] …A-OH+…B-OR2→…A-O-B…+R2OH Formula 6;

[0031] …A-OR1+…B-OR2→…A-O-B…+R1OR2 Formula 7;

[0032]

[0033] wherein n represents an integer ≥ 1, for example 1, 2, 5, 7, 10, 15, 18, 20, 25, 30, etc.

[0034] In step (2) of the present application, during the solvent evaporation process, the metal polymer molecules gradually crystallize, and under the action of the node agent, the crystals gradually produce the porous nanorods with a diameter of tens of nanometers, and multiple nanorods orderly agglomerate into a regular cuboid.

[0035] The reaction involved in step (2) is as follows:

[0036]

[0037] Taking the trimesic acid as the node agent, the reaction involved in step (2) is as follows:

[0038]

[0039] The following is a preferred technical solution of the present application, but not as a limitation on the technical solutions provided by the present application, through the following preferred technical solutions, the purpose and beneficial effects of the present application can be better achieved and realized.

[0040] As a preferred technical solution of the present application, the coordination agent A and the coordination agent B are each independently selected from any one or a combination of at least two of acetylacetone, ethylenediaminetetraacetic acid (EDTA) or hydroxyethylidene diphosphonic acid (HEDP).

[0041] Preferably, the A is selected from Zr, Hf or Ti, further preferably Ti.

[0042] Preferably, the B is selected from Ta or Nb.

[0043] Preferably, the R1 and R2 each independently represent any one of n-propyl, isopropyl, n-butyl or isobutyl, further preferably isopropyl or isobutyl.

[0044] Preferably, the A(OR1)4 is selected from Zr(OPr i )4, Hf(OBui )4 or Ti(OPr i )4.

[0045] Preferably, the B(OR2)5 is selected from Ta(OPr i )5 or Nb(OPr i )5.

[0046] wherein Pr i is isopropyl and Bu i is isobutyl.

[0047] Preferably, the solvent A and the solvent B are each independently selected from any one or a combination of at least two of ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether, ethylene glycol methyl ether, tetrahydrofuran or methyl tert-butyl ether.

[0048] As a preferred technical solution of the present application, the molar ratio of the complexing agent A and the substance A(OR1)4 is (0.1-2):1, which can be 0.1:1, 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, etc.

[0049] Preferably, the molar ratio of the solvent A and the substance A(OR1)4 is (0.5-2):1, which can be 0.5:1, 0.7:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, etc.

[0050] Preferably, the molar ratio of the complexing agent B and the substance B(OR2)5 is (0.1-2):1, which can be 0.1:1, 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, etc.

[0051] Preferably, the molar ratio of the solvent B and the substance B(OR2)5 is (0.5-2):1, which can be 0.5:1, 0.7:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1 or 2:1, etc.

[0052] Preferably, the temperature of the heating in step (1) is 45-85℃, which can be 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃ or 85℃, etc.

[0053] As a preferred technical solution of the present application, the temperature of mixing the mixed solution A and the mixed solution B is 40-90℃, for example, it can be 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃, etc.

[0054] Preferably, the node agent is selected from any one or a combination of at least two of trimesic acid, trimesic acid, methyl trimesate, ethyl trimesate, methyl trimesate, ethyl trimesate, terephthalic acid.

[0055] Preferably, the mass percentage of the node agent solution is 10-50%, for example, it can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%, etc.

[0056] Preferably, the solvent of the node agent solution is a combination including water and an alcohol compound.

[0057] Preferably, the alcohol compound is selected from any one or a combination of at least two of n-propanol, isopropanol or isobutanol.

[0058] Preferably, the mass ratio of water and alcohol compound is 1:(3-5), for example, it can be 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8 or 1:5, etc.

[0059] Preferably, the molar ratio of the node agent and A(OR1)4 added in step (2) is (0.2-1.33):1, for example, it can be 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1 or 1.33:1, etc.

[0060] Preferably, the temperature for adding the node agent solution is 70-95℃, for example, it can be 75℃, 77℃, 80℃, 81℃, 84℃, 86℃, 88℃, 90℃, 91℃, 94℃ or 95℃, etc.

[0061] Preferably, the method for adding the node agent solution includes dropwise adding.

[0062] Preferably, the dropwise adding rate is 0.25-1 drop / s, for example, it can be 1 drop / 4s, 1 drop / 3s, 1 drop / 2s or 1 drop / s, etc.

[0063] Preferably, the temperature of the reaction in step (2) is 105-125℃, for example, it can be 105℃, 108℃, 110℃, 112℃, 115℃, 118℃, 120℃, 123℃ or 125℃, etc.

[0064] Preferably, the reaction time of step (2) is 2-4h, for example, it can be 2h, 2.5h, 3h, 3.5h or 4h, etc.

[0065] As a preferred technical solution of the present application, the drying method of step (3) comprises vacuum drying.

[0066] Preferably, the temperature of the vacuum drying is 45-55℃, for example, it can be 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃ or 55℃, etc.

[0067] Preferably, the time of the vacuum drying is 10-15h, for example, it can be 10h, 11h, 12h, 13h, 14h or 15h, etc.

[0068] Preferably, the viscosity of the product obtained after drying is ≥10Pa·s, for example, it can be 10Pa·s, 12Pa·s, 14Pa·s, 16Pa·s, 18Pa·s, 20Pa·s, 22Pa·s, 25Pa·s or 25Pa·s, etc.

[0069] Preferably, the temperature of the curing reaction is 110-130℃, for example, it can be 110℃, 112℃, 114℃, 116℃, 118℃, 120℃, 122℃, 124℃, 126℃, 128℃ or 130℃, etc.

[0070] Preferably, the time of the curing reaction is 10-15h, for example, it can be 10h, 11h, 12h, 13h, 14h or 15h, etc.

[0071] As a preferred technical solution of the present application, after the crushing of step (3), the average particle size of the porous nanorods is 200-700nm, for example, it can be 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm or 700nm, etc.

[0072] Preferably, the temperature of the calcination is 600-1200℃, for example, it can be 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, etc.

[0073] Preferably, the time of the calcination is 1-8h, for example, it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h.

[0074] Preferably, the calcination is performed in an air atmosphere.

[0075] Preferably, the method of depositing carbon comprises: placing the calcined porous nanorods into a CVD deposition furnace, introducing a carbon source, and depositing carbon.

[0076] Preferably, the deposition is performed in an inert gas atmosphere.

[0077] Preferably, the inert gas comprises nitrogen.

[0078] Preferably, the nitrogen gas flow rate is 100-600 mL / min, for example, it can be 100 mL / min, 150 mL / min, 200 mL / min, 250 mL / min, 300 mL / min, 350 mL / min, 400 mL / min, 450 mL / min, 500 mL / min, 550 mL / min, or 600 mL / min, etc.

[0079] Preferably, the carbon source is selected from any one of C2H2, CH4, C2H4, toluene, or benzene, or a combination of at least two thereof.

[0080] Preferably, the carbon source gas flow rate is 30-200 mL / min, for example, it can be 30 mL / min, 50 mL / min, 70 mL / min, 80 mL / min, 100 mL / min, 120 mL / min, 140 mL / min, 160 mL / min, 180 mL / min, or 200 mL / min, etc.

[0081] Preferably, the deposition temperature is 500-1300℃, for example, it can be 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, 1100℃, 1200℃, or 1300℃, etc.

[0082] Preferably, the deposition time is 2-8 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, or 8 h, etc.

[0083] As a preferred technical solution of the present application, the preparation method of the porous carbon composite material specifically comprises the following steps:

[0084] (1) Mix the complexing agent A, at least one A(OR1)4, and the solvent A, heat and mix uniformly at 45-85℃ to obtain a mixed solution A;

[0085] Mix the complexing agent A, at least one B(OR2)5, and the solvent B, heat and mix uniformly to obtain a mixed solution B;

[0086] Wherein, A represents Zr, Hf or Ti, and B represents Ta or Nb.

[0087] R1 and R2 each independently represent a C1-C5 alkyl group;

[0088] The mass ratio of the complexing agent A and A(OR1)4 is (0.1-2):1, and the mass ratio of the solvent A and A(OR1)4 is (0.5-2):1;

[0089] The mass ratio of the complexing agent B and B(OR2)5 is (0.1-2):1, and the mass ratio of the solvent B and B(OR2)5 is (0.5-2):1;

[0090] (2) Mixing the mixed solution A and the mixed solution B at 40-90℃, and then adding a node agent solution with a mass content of 10-50% dropwise into the mixture at a dropwise adding rate of 1 drop / s, and then reacting at 105-125℃ for 2-4h to obtain a reaction liquid;

[0091] The mass ratio of the added node agent and A(OR1)4 is (0.2-1.33):1;

[0092] The solvent of the node agent solution is a combination of water and an alcohol compound, and the mass ratio of water to the alcohol compound is 1:(2-4);

[0093] (3) Vacuum drying the reaction liquid obtained in step (2) at 45-55℃ for 10-15h, and then solidifying at 110-130℃ for 10-15h to obtain a porous nanorod;

[0094] (4) crushing the porous nanorod into particles with an average particle size of 200-700nm, calcining the crushed porous nanorod in an air atmosphere at 600-1200℃ for 1-8h, and then placing the calcined porous nanorod in a CVD deposition furnace, introducing a carbon source in a nitrogen atmosphere at 500-1300℃, and depositing carbon for 2-8h to obtain a porous carbon composite material;

[0095] The gas flow rate of the nitrogen is 100-600mL / min, and the gas flow rate of the carbon source is 30-200mL / min.

[0096] In a second aspect, the present application provides a porous carbon composite material, which is prepared by the preparation method as described in the first aspect.

[0097] Preferably, the specific surface area of the porous carbon composite material is 500-2000m 2 / g (for example, it can be 500m 2 / g, 700m 2 / g, 800m 2 / g, 1000 m 2 / g, 1200 m 2 / g, 1500 m 2 / g, 1600 m 2 / g, 1800 m 2 / g or 2000 m 2 / g, further preferably 1000-1800 m 2 / g, further preferably 1500-1800 m 2 / g.

[0098] Preferably, the total pore volume of the porous carbon composite material is 0.4-2 cm 3 / g (e.g. can be 0.4 cm 3 / g, 0.6 cm 3 / g, 0.7 cm 3 / g, 1.0 cm 3 / g, 1.1 cm 3 / g, 1.4 cm 3 / g, 1.6 cm 3 / g, 1.8 cm 3 / g or 2 cm 3 / g, further preferably 0.6-1.2 cm 3 / g, further preferably 0.7-1.1 cm 3 / g.

[0099] Preferably, the BJH mesopore volume of the porous carbon composite material is 0.10-0.45 cm 3 / g, e.g. can be 0.10 cm 3 / g, 0.15 cm 3 / g, 0.20 cm 3 / g, 0.25 cm 3 / g, 0.30 cm 3 / g, 0.35 cm 3 / g, 0.40 cm 3 / g or 0.45 cm 3 / g or more.

[0100] Preferably, the HK micropore volume of the porous carbon composite material is 0.50-0.75 cm 3 / g, e.g. can be 0.50 cm 3 / g, 0.52 cm 3 / g, 0.55 cm 3 / g, 0.57 cm 3 / g, 0.60 cm 3 / g, 0.63 cm 3 / g, 0.65 cm3 / g, 0.68 cm 3 / g, 0.70 cm 3 / g, 0.72 cm 3 / g or 0.75 cm 3 / g, etc.

[0101] Preferably, the microporosity of the porous carbon composite is 60-95%, for example it can be 60%, 63%, 66%, 68%, 70%, 72%, 75%, 78%, 81%, 84%, 88%, 90%, 93% or 95%, etc.

[0102] Preferably, the average pore size of the porous carbon composite is 0.5-10 nm (for example it can be 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, etc.), further preferably 1-10 nm, and still further preferably 2-8 nm.

[0103] Preferably, the D0 particle size of the porous carbon composite is > 0.2 μm, for example it can be 0.2 μm, 1 μm, 2 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm or 25 μm, etc.

[0104] Preferably, the D 10 particle size of the porous carbon composite is > 2 μm, for example it can be 2 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm or 25 μm, etc.

[0105] Preferably, the D 50 particle size of the porous carbon composite is 4.0-11 μm, for example it can be 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or 11 μm, etc.

[0106] Preferably, the D 90 particle size of the porous carbon composite is < 13 μm, for example it can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm or 13 μm, etc.

[0107] Preferably, the D 100 particle size of the porous carbon composite is < 25 μm, for example it can be 1 μm, 2 μm, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm or 25 μm, etc.

[0108] Preferably, the particle size distribution of the porous carbon composite is: (D 90 particle size - D 10Particle size) / D 50 Particle size ≤1.1, for example, can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1 or 1.1, etc.

[0109] Preferably, the bulk density of the porous carbon composite material is 0.1-0.3 g / cm 3 , for example, can be 0.1 g / cm 3 , 0.12 g / cm 3 , 0.14 g / cm 3 , 0.16 g / cm 3 , 0.18 g / cm 3 , 0.2 g / cm 3 , 0.22 g / cm 3 , 0.24 g / cm 3 , 0.26 g / cm 3 , 0.28 g / cm 3 or 0.3 g / cm 3 , etc.

[0110] Preferably, the tap density of the porous carbon composite material is 0.2-0.5 g / cm 3 , for example, can be 0.2 g / cm 3 , 0.22 g / cm 3 , 0.25 g / cm 3 , 0.27 g / cm 3 , 0.3 g / cm 3 , 0.33 g / cm 3 , 0.36 g / cm 3 , 0.39 g / cm 3 , 0.42 g / cm 3 , 0.46 g / cm 3 or 0.5 g / cm 3 , etc.

[0111] Preferably, the resistance of the porous carbon composite material at 20 MPa is 0-2 Ω, for example, can be 0 Ω, 0.2 Ω, 0.4 Ω, 0.6 Ω, 0.8 Ω, 1 Ω, 1.2 Ω, 1.4 Ω, 1.6 Ω, 1.8 Ω or 2 Ω, etc.

[0112] In a third aspect, the present application provides a porous carbon material, the raw material for preparing the porous carbon material comprising the porous carbon composite material according to the second aspect and an acid.

[0113] Preferably, the acid comprises HF.

[0114] Preferably, the porous carbon material is prepared by a method comprising the following steps:

[0115] The porous carbon composite material is subjected to acid washing to obtain the porous carbon material.

[0116] Preferably, the acid washing is performed at a temperature of 20-60℃ (for example, it can be 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ or 60℃, etc.) for 1-10h (for example, it can be 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, etc.).

[0117] In the present application, the transition metal oxide in the porous carbon composite material is removed by acid washing to obtain the porous carbon material.

[0118] In a fourth aspect, the present application provides a silicon-carbon composite material, which comprises a first silicon-carbon composite material and / or a second silicon-carbon composite material.

[0119] The preparation raw material of the first silicon-carbon composite material comprises the porous carbon composite material according to the second aspect.

[0120] The preparation raw material of the second silicon-carbon composite material comprises the porous carbon material according to the third aspect.

[0121] Preferably, the deposition amount of silicon in the first silicon-carbon composite material is 40%-90% (for example, it can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%, etc.) of the pore volume of the first silicon-carbon composite material, and more preferably 60%-80%.

[0122] Preferably, the deposition amount of silicon in the second silicon-carbon composite material is 40%-90% (for example, it can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%, etc.) of the pore volume of the second silicon-carbon composite material, and more preferably 60%-80%.

[0123] Preferably, the first silicon-carbon composite material and the second silicon-carbon composite material are each independently prepared by a method comprising the following steps:

[0124] The porous carbon composite material according to the third aspect or the porous carbon material according to the second aspect is placed in a deposition furnace, heated to 300-1000℃ (for example, it can be 300℃, 400℃, 500℃, 600℃, 700℃, 800℃, 900℃ or 1000℃, etc.), and a first mixed gas comprising a silicon source gas and an inert gas is introduced to perform silicon deposition to obtain the first silicon-carbon composite material or the second silicon-carbon composite material.

[0125] Preferably, the inert gas is selected from any one or a combination of at least two of nitrogen, neon, argon, krypton, xenon and radon.

[0126] Preferably, the silicon source gas is selected from any one or a combination of at least two of monosilane, disilane, dichlorodisilane or trichlorosilane.

[0127] Preferably, the volume percentage of the silicon source gas is 70% to 100% (for example, it can be 70%, 75%, 80%, 85%, 90%, 95% or 100%, etc.) and the volume percentage of the inert gas is 0% to 30% (for example, it can be 0%, 5%, 10%, 15%, 20%, 25% or 30%, etc.) based on 100% of the volume percentage of the first mixed gas.

[0128] Preferably, the flow rate of the first mixed gas is 0.1 to 50 L / min (for example, it can be 0.1 L / min, 1 L / min, 5 L / min, 10 L / min, 15 L / min, 20 L / min, 25 L / min, 30 L / min, 35 L / min, 40 L / min, 45 L / min or 50 L / min, etc.), and further preferably 5 to 20 L / min.

[0129] Preferably, the pressure of the silicon deposition is 5 to 10 kPa, for example, it can be 5 kPa, 5.5 kPa, 6 kPa, 6.5 kPa, 7 kPa, 7.5 kPa, 8 kPa, 8.5 kPa, 9 kPa, 9.5 kPa or 10 kPa, etc.

[0130] Preferably, after the silicon deposition, a post-processing step is further included.

[0131] Preferably, the method of post-processing includes: cooling to 400 to 600°C (for example, it can be 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, 520°C, 540°C, 560°C, 580°C or 600°C, etc.), and introducing a second mixed gas including a carbon source gas and an inert gas to perform surface carbon coating to obtain a carbon coating layer.

[0132] Preferably, the carbon source gas is selected from an alkane compound with a cracking temperature of 400 to 800°C (for example, it can be 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C or 800°C, etc.), and further preferably ethyne or ethylene.

[0133] Preferably, the volume percentage of the carbon source gas in the second mixed gas is 60% to 80% (for example, it can be 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, etc.), and the volume percentage of the inert gas is 20% to 40% (for example, it can be 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc.), based on 100% of the volume percentage of the second mixed gas.

[0134] Preferably, the flow rate of the second mixed gas is 0.1 to 50 L / min (for example, it can be 0.1 L / min, 1 L / min, 5 L / min, 10 L / min, 15 L / min, 20 L / min, 25 L / min, 30 L / min, 35 L / min, 40 L / min, 45 L / min, or 50 L / min, etc.), and further preferably 5 to 20 L / min.

[0135] Preferably, the surface carbon coating time is 1 to 2 hours, for example, it can be 1 hour, 1.5 hours, or 2 hours, etc.

[0136] Preferably, the mass percentage of the carbon coating layer is 0.5wt% to 10wt% (for example, it can be 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, or 10wt%, etc.), and further preferably 2wt% to 5wt%, based on 100% of the mass percentage of the first or second silicon-carbon composite material.

[0137] The first silicon-carbon composite material is prepared by a method comprising the following steps:

[0138] The porous carbon composite material as described in the second aspect is placed in a deposition furnace, heated to 300 to 1000°C, and a first mixed gas comprising a silicon source gas and an inert gas is introduced to deposit silicon at a pressure of 5 to 10 kPa, then cooled to 400 to 600°C, and a second mixed gas comprising a carbon source gas and an inert gas is introduced to perform surface carbon coating for 1 to 2 hours to obtain a carbon coating layer, thereby obtaining the first silicon-carbon composite material;

[0139] The volume percentage of the silicon source gas in the first mixed gas is 70% to 100%, and the volume percentage of the inert gas is 0% to 30%, based on 100% of the volume percentage of the first mixed gas.

[0140] The flow rate of the first mixed gas is 0.1 to 50 L / min.

[0141] The volume percentage of the carbon source gas is 60% to 80% and the volume percentage of the inert gas is 20% to 40% based on 100% of the volume percentage of the second mixed gas;

[0142] The flow rate of the second mixed gas is 0.1 to 50 L / min;

[0143] The mass percentage of the carbon coating layer is 0.5 wt% to 10 wt% based on 100% of the mass percentage of the first silicon-carbon composite material.

[0144] The second silicon-carbon composite material is prepared by the following method, which comprises the following steps:

[0145] The porous carbon composite material as described in the third aspect is placed in a deposition furnace, heated to 300 to 1000℃, and a first mixed gas comprising a silicon source gas and an inert gas is introduced to perform silicon deposition at a pressure of 5 to 10 kPa, and then cooled to 400 to 600℃, and a second mixed gas comprising a carbon source gas and an inert gas is introduced to perform surface carbon coating for 1 to 2 hours to obtain a carbon coating layer, thereby obtaining the second silicon-carbon composite material;

[0146] The volume percentage of the silicon source gas is 70% to 100% and the volume percentage of the inert gas is 0% to 30% based on 100% of the volume percentage of the first mixed gas;

[0147] The flow rate of the first mixed gas is 0.1 to 50 L / min;

[0148] The volume percentage of the carbon source gas is 60% to 80% and the volume percentage of the inert gas is 20% to 40% based on 100% of the volume percentage of the second mixed gas;

[0149] The flow rate of the second mixed gas is 0.1 to 50 L / min;

[0150] The mass percentage of the carbon coating layer is 0.5 wt% to 10 wt% based on 100% of the mass percentage of the second silicon-carbon composite material.

[0151] In a fifth aspect, the present application provides a lithium ion battery, wherein the raw materials for preparing the lithium ion battery comprise at least one of the porous carbon composite material as described in the second aspect, the porous carbon material as described in the third aspect, or the silicon-carbon composite material as described in the fourth aspect.

[0152] Preferably, at least one of the porous carbon composite material as described in the second aspect, the porous carbon material as described in the third aspect, or the silicon-carbon composite material as described in the fourth aspect is used for preparing a lithium ion battery anode.

[0153] Compared with the prior art, the present application has the following beneficial effects:

[0154] (1) In the present application, the metal polymer method is used to prepare the porous carbon composite material without removing the template, and the transition metal oxide is used as the template agent to improve the electrochemical performance of the porous carbon composite material; in the present application, the metal polymer method is a liquid phase reaction, which is easy to transfer and process materials, and compared with the MOF method, the metal polymer method in the present application does not need high-temperature and high-pressure equipment, and by virtue of its own electrostatic self-assembly ability, the metal elements can be uniformly mixed at the atomic level, which greatly reduces the energy required to form a solid solution and reduces the production energy consumption.

[0155] (2) The traditional metal polymer method is difficult to control the morphology of the final sample, and the formed particles are large and the pore structure is not obvious, and the use of the multi-function node agent in the present application successfully realizes the controllable sample morphology.

[0156] (3) In the present application, the transition metal oxide is coated by CVD to obtain the porous carbon composite material, wherein the high modulus and stability of the transition metal oxide serve as the support of the skeleton structure, and the carbon layer with low modulus serves as the buffer layer, which can ensure the stability of the skeleton in the mechanical structure; at the same time, the transition metal oxide has good lithium storage capacity, and after being combined with carbon, the conductivity of the material can be improved, and the transition metal oxide porous material is a good skeleton and can be used for the preparation of silicon-carbon negative electrode material.

[0157] (4) In the present application, the low-density porous carbon material is prepared from the porous carbon composite material, and the porous carbon composite material and the porous carbon material can be used for the preparation of silicon-carbon composite material, and the porous carbon composite material, the porous carbon material and the silicon-carbon composite material can be used for the preparation of lithium ion battery negative electrode, and the lithium ion battery prepared by the negative electrode has good electrical performance. BRIEF DESCRIPTION OF DRAWINGS

[0158] Figure 1 is the SEM image of the porous carbon composite material provided in Example 1 under 15000 magnification;

[0159] Figure 2 is the SEM image of the first silicon-carbon composite material provided in Application Example 1 under 3000 magnification;

[0160] Figure 3 is the specific capacity-voltage curve of the lithium ion battery prepared by using the first silicon-carbon composite material provided in Application Example 1 as the lithium ion battery negative electrode material. DETAILED DESCRIPTION

[0161] The technical solutions of the present application will be further illustrated below in combination with the drawings and through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0162] Embodiment 1

[0163] The present embodiment provides a porous carbon composite material and a preparation method thereof, and the preparation method is as follows:

[0164] (1) 2 mol of acetylacetone is added dropwise into a reaction container containing 1 mol of Ti(OPr i )4, 2 mol of ethylene glycol diethyl ether is added thereto, mixed uniformly, heated at 60℃, and mixed uniformly to obtain a mixed solution A;

[0165] 2 mol of acetylacetone is added dropwise into a reaction container containing 1 mol of Nb(OPr i )5, 2 mol of ethylene glycol diethyl ether is added thereto, mixed uniformly, heated at 60℃, and mixed uniformly to obtain a mixed solution B;

[0166] (2) The mixed solution A and the mixed solution B are mixed at 50℃, heated to 70℃, and then a solution of 30% by mass of trimesic acid is added dropwise at a dropwise rate of 1 drop / s, and then reacted at 105℃ for 3 h to obtain a reaction solution;

[0167] The molar ratio of the added trimesic acid to Ti(OPr i )4 is 0.33:1;

[0168] The solvent of the trimesic acid solution is composed of water and n-propanol at a mass ratio of 1:3;

[0169] (3) The reaction solution obtained in step (2) is vacuum dried at 50℃ for 2 h, and then solidified at 120℃ for 12 h to obtain a porous nanorod;

[0170] (4) The porous nanorod is crushed to particles with an average particle size of 500 nm, calcined at 800℃ for 5 h in an air atmosphere, and then the calcined porous nanorod is placed in a CVD deposition furnace, C2H2 is introduced at 700℃ in a nitrogen atmosphere, and carbon is deposited for 4 h to obtain a porous carbon composite material;

[0171] The gas flow rate of nitrogen is 300 mL / min; and the gas flow rate of C2H2 is 100 mL / min.

[0172] The microstructure of the porous carbon composite material provided in the present embodiment is characterized using an electron microscope (JSM-6700F) at a magnification of 15000, as shown inFigure 1 It can be known that the preparation method provided by the present application can regulate the micro-morphology of the porous carbon composite material. Figure 1 It can be known that the preparation method provided by the present application can regulate the micro-morphology of the porous carbon composite material.

[0173] Example 2

[0174] The present embodiment provides a porous carbon composite material and a preparation method thereof, and the preparation method is as follows:

[0175] (1) 1 mol of acetylacetone is added dropwise into a reaction container containing 1 mol of Ti(OPr i )4, 1.5 mol of ethylene glycol diethyl ether is added thereto, and the mixture is uniformly mixed and heated at 85℃ to obtain a mixed solution A;

[0176] 1 mol of acetylacetone is added dropwise into a reaction container containing 1 mol of Nb(OPr i )5, 1.5 mol of ethylene glycol diethyl ether is added thereto, and the mixture is uniformly mixed and heated at 85℃ to obtain a mixed solution B;

[0177] (2) The mixed solution A and the mixed solution B are mixed at 60℃, and the temperature is raised to 95℃, and then a solution of 20% of trimesic acid by mass is added dropwise at a dropwise adding rate of 1 drop / s, and then the reaction is carried out at 125℃ for 4h to obtain a reaction solution;

[0178] The molar ratio of the added trimesic acid to Ti(OPr i )4 is 1:1;

[0179] The solvent of the trimesic acid solution is composed of water and n-propanol at a mass ratio of 1:3;

[0180] (3) The reaction solution obtained in step (2) is vacuum dried at 50℃ for 5h, and then solidified at 120℃ for 12h to obtain a porous nanorod;

[0181] (4) The porous nanorod is crushed to particles with an average particle size of 500nm, calcined at 900℃ for 4h in an air atmosphere, and then the calcined porous nanorod is placed in a CVD deposition furnace, C2H2 is introduced in a nitrogen atmosphere at 650℃, and carbon is deposited for 8h to obtain a porous carbon composite material;

[0182] The gas flow rate of nitrogen is 600mL / min; and the gas flow rate of C2H2 is 200mL / min.

[0183] Example 3

[0184] The embodiment provides a porous carbon composite material and a preparation method thereof, and the preparation method is as follows:

[0185] (1) 0.1 mol of ethylenediaminetetraacetic acid is added into a reaction container containing 1 mol of Zr(OPr i )4, 0.5 mol of ethylene glycol dimethyl ether is added into the reaction container, the mixture is uniformly mixed, and the mixture is uniformly heated at 45 DEG C to obtain a mixed solution A;

[0186] 0.1 mol of ethylenediaminetetraacetic acid is added into a reaction container containing 1 mol of Ta(OPr i )5, 0.5 mol of ethylene glycol dimethyl ether is added into the reaction container, the mixture is uniformly mixed, and the mixture is uniformly heated at 45 DEG C to obtain a mixed solution B;

[0187] (2) The mixed solution A and the mixed solution B are mixed at 55 DEG C, and the temperature is raised to 80 DEG C; 10% of a methyl m-phenylenedimethylisocyanate solution is added dropwise into the mixed solution at a dropwise adding rate of 1 drop / s, and then the reaction is carried out at 120 DEG C for 2 h to obtain a reaction solution;

[0188] The molar ratio of the added methyl m-phenylenedimethylisocyanate and Zr(OPr i )4 is 1.33:1;

[0189] The solvent of the methyl m-phenylenedimethylisocyanate solution is composed of water and n-propanol at a mass ratio of 1:3;

[0190] (3) The reaction solution obtained in the step (2) is vacuum dried at 45 DEG C for 3 h, and then is solidified at 110 DEG C for 15 h to obtain a porous nanorod;

[0191] (4) The porous nanorod is crushed into particles with an average particle size of 300 nm, and then is calcined at 1200 DEG C for 4 h in an air atmosphere; then the calcined porous nanorod is placed in a CVD deposition furnace, C2H2 is introduced into the CVD deposition furnace at 500 DEG C in a nitrogen atmosphere, and carbon is deposited for 8 h to obtain a porous carbon composite material;

[0192] The gas flow rate of the nitrogen is 100 mL / min; and the gas flow rate of the C2H2 is 80 mL / min.

[0193] Embodiment 4

[0194] The embodiment provides a porous carbon composite material and a preparation method thereof, and the preparation method is as follows:

[0195] (1) 0.5 mol of hydroxyethylidene diphosphonic acid is added into a reaction container containing 1 mol of Hf(OBu i)4 into a reaction vessel, 1 mol ethylene glycol ethyl ether is added thereto, mixed uniformly, heated at 75°C, mixed uniformly, to obtain a mixed solution A;

[0196] 0.5 mol hydroxyethylidene diphosphonic acid is added dropwise into a reaction vessel containing 1 mol Nb(OPr i )5, 1 mol ethylene glycol ethyl ether is added thereto, mixed uniformly, heated at 75°C, mixed uniformly, to obtain a mixed solution B;

[0197] (2) At 70°C, the mixed solution A and the mixed solution B are mixed, warmed to 80°C, 25% mass content of a trimesic acid solution is added dropwise thereto at a dropwise adding rate of 1 drop / s, and then reacted at 125°C for 24 h to obtain a reaction liquid;

[0198] The mass ratio of the trimesic acid and Hf(OBu i )4 added is 0.8:1;

[0199] The solvent of the trimesic acid solution is composed of water and n-propanol at a mass ratio of 1:3;

[0200] (3) The reaction liquid obtained in step (2) is vacuum dried at 55°C for 6 h, and then solidified at 130°C for 10 h to obtain a porous nanorod;

[0201] (4) The porous nanorod is crushed to an average particle size of 350 nm, calcined at 600°C for 2 h in an air atmosphere, and then the calcined porous nanorod is placed in a CVD deposition furnace, C2H2 is introduced at 1300°C in a nitrogen atmosphere, and carbon is deposited for 3 h to obtain a porous carbon composite material;

[0202] The gas flow rate of the nitrogen is 300 mL / min; and the gas flow rate of the C2H2 is 30 mL / min.

[0203] Example 5

[0204] The present embodiment provides a porous carbon composite material and a preparation method thereof, which are different from those of example 1 only in that the mass ratio of the trimesic acid and Ti(OPr i )4 added in step (2) is 0.2:1, and other conditions are the same as those of example 1.

[0205] Example 6

[0206] The present embodiment provides a porous carbon composite material and a preparation method thereof, which are different from those of example 1 only in that the mass ratio of the trimesic acid and Ti(OPr i )4 added in step (2) is 1.33:1, and other conditions are the same as those of example 1.

[0207] Example 7

[0208] This embodiment provides a porous carbon composite material and its preparation method. The only difference from Example 1 is that, in step (2), pyromellitic acid and Ti(OPr) are added. i The molar ratio of 4 was 0.1:1, and other conditions were the same as in Example 1.

[0209] Example 8

[0210] This embodiment provides a porous carbon composite material and its preparation method. The only difference from Example 1 is that, in step (2), pyromellitic acid and Ti(OPr) are added. i The molar ratio of 4 was 1.6:1, and other conditions were the same as in Example 1.

[0211] Example 9

[0212] This embodiment provides a porous carbon composite material and its preparation method. The only difference from Example 1 is that the pyromellitic acid used in step (2) is replaced with terephthalic acid, and the other conditions are the same as in Example 1.

[0213] Comparative Example 1

[0214] This comparative example provides a porous carbon composite material and its preparation method. The only difference from Example 1 is that acetylacetone was not added to either mixture A or mixture B in step (1), and the other conditions were the same as in Example 1.

[0215] Comparative Example 2

[0216] This comparative example provides a porous carbon composite material and its preparation method. The only difference from Example 1 is that in step (2), the pyromellitic acid solution is replaced with 1 / 4 volume of water, and the other conditions are the same as in Example 1.

[0217] The properties of the porous carbon composite materials provided in the above embodiments and comparative examples were tested, and the specific test methods are as follows:

[0218] Scanning Electron Microscopy (SEM) Testing: The surface morphology, particle size, and other characteristics of the samples were observed using a Rigaku JSM-6700F scanning electron microscope from Japan. The emission voltage was 5KV, and the powder surface was vacuum sputtered with gold for 2 minutes. The samples were analyzed by receiving, amplifying, and displaying the physical signals such as secondary electrons, double-scattered electrons, transmitted electrons, absorbed electrons, visible light, and X-rays generated by scanning the sample with a high-energy electron beam, thereby obtaining various information about the sample morphology.

[0219] Specific surface area, single-point adsorption total pore volume, BJH mesopore volume, HK micropore volume, average pore size detection, micropore rate: JW-BK300C according to GB / T 1958-2017, respectively, the adsorption field number C value is greater than 0, the linear fitting degree is greater than 0.999, NLDFT model. Particle size detection: laser method and MASTERSIZER 3000 measuring instrument are selected to measure the particle size of the material.

[0220] Loose bulk density: according to GB / T 31057.1-2014.

[0221] Tap density: according to GB / T 21354-2008 and GB / T 31057.2-2018.

[0222] Resistance at 20MPa: four-probe method, by semiconductor powder resistivity instrument, the resistivity of the sample under 20MPa pressure.

[0223] The performance test results are shown in the following table 1 and table 2:

[0224] Table 1

[0225]

[0226] Table 2

[0227]

[0228] From the above, the present application uses metal polymer method, uses transition metal oxide as template agent, realizes coating of transition metal oxide by CVD, and prepares porous carbon composite material without removing template and with excellent performance, the specific surface area is 500-2000m 2 / g, the single-point adsorption total pore volume is 0.4-2cm 3 / g, the BJH mesopore volume is 0.10-0.45cm 3 / g, the HK micropore volume is 0.50-0.75cm 3 / g, the micropore rate is 60-95%, the D0 particle size is greater than or equal to 0.2μm, the D 10 particle size is greater than or equal to 2μm, the D 50 particle size is 4.0-11μm, the D 90 particle size is less than or equal to 13μm, the D 100 particle size is less than or equal to 25μm, the D 90 particle size-D 10 particle size) / D 50 particle size is less than or equal to 1.1, the loose bulk density is 0.1-0.3g / cm 3 , the tap density is 0.2-0.5g / cm 3The resistance at 20 MPa is 0-2 ohms.

[0229] The present application further improves the performance of the porous carbon composite material by using specific node agents and complexing agents, and further controlling the amount of the node agent in a specific range, and the specific surface area of the porous carbon composite material is 1400-1800 m 2 / g, the total pore volume of single-point adsorption is 0.8-1.1 cm 3 / g, the BJH mesopore volume is 0.20-0.40 cm 3 / g, the HK micropore volume is 0.50-0.70 cm 3 / g, the micropore rate is 63-78%, and the resistance at 20 MPa is 0.03-0.12 ohms.

[0230] As can be seen from the contents of Examples 7-8, if the amount of the node agent is too small or too large, the comprehensive performance of the porous carbon composite material prepared is poor.

[0231] As can be seen from the contents of Example 9, if a difunctional node agent is selected, compared with Example 1, the comprehensive performance of the porous carbon composite material prepared is poor.

[0232] As can be seen from the contents of Comparative Examples 1-2, if no complexing agent or node agent is used in the preparation of the porous carbon composite material, the morphology of the porous carbon composite material prepared is uncontrollable, and the comprehensive performance is poor.

[0233] Application Examples 1-9 and Comparative Application Examples 1-2

[0234] The application examples 1-9 and comparative application examples 1-2 respectively provide a first silicon-carbon composite material and a preparation method thereof, and the preparation method of the silicon-carbon composite material is as follows:

[0235] The porous carbon composite material is placed in a deposition furnace, heated to 800 DEG C, and a first mixed gas comprising a silicon source gas and an inert gas is introduced, and silicon deposition is carried out at a pressure of 8 kPa, and then the temperature is lowered to 500 DEG C, and a second mixed gas comprising a carbon source gas and an inert gas is introduced, and surface carbon coating is carried out for 2 hours to obtain a carbon coating layer, thereby obtaining the first silicon-carbon composite material;

[0236] The volume percentage of the silicon source gas is 80% and the volume percentage of the inert gas is 20% based on 100% of the volume percentage of the first mixed gas;

[0237] The flow rate of the first mixed gas is 20 L / min;

[0238] The volume percentage of the carbon source gas is 70% and the volume percentage of the inert gas is 30% based on 100% of the volume percentage of the second mixed gas;

[0239] The flow rate of the second mixed gas is 25 L / min;

[0240] The mass percentage content of the carbon-coated layer is shown in the following table, taking the mass percentage content of the first silicon-carbon composite material as 100%.

[0241] The microstructure of the first silicon-carbon composite material provided in Application Example 1 was characterized using an electron microscope (JSM-6700F) under a magnification of 3000, as shown in Figure 2 Figure 2 It can be seen from the above that the preparation method provided by the present application produces a first silicon-carbon composite material with regular microstructure.

[0242] The performance of the first silicon-carbon composite materials provided in the above application examples and comparative application examples was tested, and the specific test methods are as follows:

[0243] The charge-discharge performance test was performed on the simulated battery using a LAND CT2001A battery test system, and the voltage test range was 0-1.8 V. The preparation of the simulated battery included the following steps: according to the mass ratio of silicon-carbon composite material: conductive carbon black: polyvinylidene fluoride (PVDF) being 85:5:10, the required silicon-carbon composite material, conductive carbon black and PVDF were weighed, the silicon-carbon composite material and conductive carbon black were ground in a mortar to mix uniformly, and were added to the N-methyl pyrrolidone (NMP) solution of PVDF, stirred uniformly, to prepare a slurry, and then the slurry was coated on a copper foil, dried, and roll-pressed to form a pole piece. A metal lithium sheet was used as the counter electrode, Celgard2400 was used as the separator, 1 mol / L LiPF6 / EC (ethylene carbonate) + DMC (dimethyl carbonate) + EMC (methyl ethyl carbonate) (volume ratio 1:1:1) was used as the electrolyte, and the simulated battery was assembled in an argon glove box, and tested after standing for 12 h.

[0244] Mass percentage content of carbon-coated layer: mass percentage content of carbon-coated layer = (mass of first silicon-carbon composite material x carbon content in composite material - mass of porous carbon composite x carbon content in porous carbon) ÷ mass of first silicon-carbon composite material x 100%;

[0245] Delithiation capacity: specific capacity corresponding to the first discharge process in the constant current charge-discharge test;

[0246] Lithium intercalation capacity: specific capacity corresponding to the first charge process in the constant current charge-discharge test;

[0247] Initial efficiency: initial efficiency = delithiation capacity ÷ lithium intercalation capacity x 100%.

[0248] The above test data is shown in Table 3 below:

[0249] Table 3​

[0250]

[0251] The first silicon-carbon composite material provided in application example 1 is used as a negative electrode material of a lithium ion battery, and the specific capacity-voltage curve of the lithium ion battery prepared is shown in Figure 3 It can be known from Figure 3 that the delithiation capacity of the negative electrode is 1976.6 mAh / g, the lithium intercalation capacity is 2228.4 mAh / g, the initial efficiency is 88.7%, and the material exhibits excellent energy storage performance and stability.

[0252] From the above, it can be known that the raw material of the porous carbon composite material prepared by the specific preparation method in the application, and the first silicon-carbon composite material prepared are suitable for being used as a negative electrode material of a lithium ion battery, and the lithium ion battery prepared therefrom has excellent electrical performance, the delithiation capacity is 1500-2100 mAh / g, the lithium intercalation capacity is 1700-2300 mAh / g, the initial efficiency is greater than 85%, and the mass percentage content of the carbon coating layer is 3%-6%.

[0253] From the contents of application examples 7-8, it can be known that if the amount of the node agent is too small or too large when the porous carbon composite material is prepared, the comprehensive performance of the porous carbon composite material prepared is poor, the performance of the first silicon-carbon composite material prepared therefrom is also poor, and further the performance of the lithium ion battery prepared by using the first silicon-carbon composite material as a negative electrode material of a lithium ion battery is also poor.

[0254] From the content of example 9, it can be known that if a difunctional node agent is selected, the morphology of the porous carbon composite material cannot be controlled, the comprehensive performance of the porous carbon composite material prepared is poor, the performance of the first silicon-carbon composite material prepared therefrom is also poor, and further the performance of the lithium ion battery prepared by using the first silicon-carbon composite material as a negative electrode material of a lithium ion battery is also poor.

[0255] From the contents of comparative examples 1-2, it can be known that if no coordination agent or node agent is used in the process of preparing the porous carbon composite material, the morphology of the porous carbon composite material prepared is uncontrollable, and the comprehensive performance is poor, the performance of the first silicon-carbon composite material prepared therefrom is also poor, and further the performance of the lithium ion battery prepared by using the first silicon-carbon composite material as a negative electrode material of a lithium ion battery is also poor.

[0256] In summary, the application uses a metal polymer method, uses a transition metal oxide as a template agent, and realizes coating of the transition metal oxide through CVD to prepare a porous carbon composite material without removing the template and with excellent performance. The porous carbon composite material can be used to prepare a porous carbon material, and the porous carbon composite material and the porous carbon material can be used to prepare a silicon-carbon composite material, which can be used to prepare a lithium ion battery negative electrode, thereby improving the electrical performance of the lithium ion battery.

[0257] The applicant declares that the detailed process flow of the application is illustrated by the above-mentioned embodiments, but the application is not limited to the above-mentioned detailed process flow, that is, it does not mean that the application must rely on the above-mentioned detailed process flow to be implemented. It should be understood by those skilled in the art that any improvement of the application, equivalent replacement of each raw material of the product of the application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the application.

Claims

1. A method for producing a porous carbon composite material, characterized by, The preparation method comprises the following steps: (1) mixing the complexing agent A, at least one A(OR1)4, and a solvent A, heating and uniformly mixing at 45-85°C to obtain a mixed solution A; mixing the complexing agent A, at least one B(OR2)5, and a solvent B, heating and uniformly mixing to obtain a mixed solution B; wherein A in A(OR1)4 represents Zr, Hf or Ti, and B in B(OR2)5 represents Ta or Nb; R1 and R2 each independently represent C1-C5 alkyl; the molar ratio of the complexing agent A to A(OR1)4 is (0.1-2):1, and the molar ratio of the solvent A to A(OR1)4 is (0.5-2):1; the molar ratio of the complexing agent B to B(OR2)5 is (0.1-2):1, and the molar ratio of the solvent B to B(OR2)5 is (0.5-2):1; (2) mixing the mixed solution A and the mixed solution B at 40-90°C, heating to 70-95°C, and then adding a node agent solution with a mass content of 10-50% at a drop rate of 1 drop / s, and then reacting at 105-125°C for 2-4 h to obtain a reaction solution; wherein the molar ratio of the added node agent to A(OR1)4 is (0.2-1.33):1; the solvent of the node agent solution is a combination comprising water and an alcohol compound, and the mass ratio of water to the alcohol compound is 1:(2-4); (3) vacuum drying the reaction solution obtained in step (2) at 45-55°C for 10-15 h, and then solidifying at 110-130°C for 10-15 h to obtain porous nanorods; (4) crushing the porous nanorods, calcining, and then placing the calcined porous nanorods in a CVD deposition furnace, introducing a carbon source, depositing carbon, and obtaining a porous carbon composite material; wherein the gas flow rate of nitrogen is 100-600 mL / min, and the gas flow rate of the carbon source is 30-200 mL / min.

2. The production method according to claim 1, characterized by, The complexing agent A and the complexing agent B are each independently selected from any one or a combination of at least two of acetylacetone, ethylenediaminetetraacetic acid, or hydroxyethylidene diphosphonic acid.

3. The preparation method according to claim 1, characterized in that, A in A(OR1)4 is Ti.

4. The method of claim 1, wherein, R1 and R2 each independently represent any one of n-propyl, i-propyl, n-butyl, or i-butyl.

5. The preparation method according to claim 4, characterized in that, R1 and R2 each independently are i-propyl or i-butyl.

6. The method of claim 1, wherein, The A(OR1)4is selected from any one of Zr(OPr i )4, Hf(OBu i )4, or Ti(OPr i )4.

7. The preparation method according to claim 1, characterized in that, said B(OR2)5is selected from Ta(OPr i )5or Nb(OPr i )5.

8. The method of claim 1, wherein, The solvent A and the solvent B are each independently selected from any one or a combination of at least two of ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether, ethylene glycol methyl ether, tetrahydrofuran, or methyl tert-butyl ether.

9. The method of claim 1, wherein, The node agent is selected from any one or a combination of at least two of trimesic acid, trimesic acid methyl ester, trimesic acid ethyl ester, trimesic acid methyl ester, trimesic acid ethyl ester, trimesic acid methyl ester, trimesic acid ethyl ester, terephthalic acid.

10. The method of claim 1, wherein, The alcohol compound is selected from any one or a combination of at least two of n-propanol, i-propanol, or i-butanol.

11. A porous carbon composite material, characterized by, The porous carbon composite material is prepared by the preparation method according to any one of claims 1-10.

12. The porous carbon composite of claim 11, wherein, The specific surface area of the porous carbon composite is 500-2000 m 2 / g.

13. The porous carbon composite of claim 12, wherein, The specific surface area of the porous carbon composite is 1000-1800 m 2 / g.

14. The porous carbon composite of claim 13, wherein, The specific surface area of the porous carbon composite is 1500-1800 m 2 / g.

15. The porous carbon composite of claim 11, wherein, The total pore volume of the single-point adsorption of the porous carbon composite is 0.4-2 cm 3 / g.

16. The porous carbon composite of claim 15, wherein, The total pore volume of the single point adsorption of the porous carbon composite is 0.6-1.2 cm 3 / g.

17. The porous carbon composite of claim 16, wherein, The total pore volume of the single point adsorption of the porous carbon composite is 0.7~1.1 cm 3 / g.

18. The porous carbon composite of claim 11, wherein, The BJH mesopore volume of the porous carbon composite is 0.10 to 0.45 cm 3 / g.

19. The porous carbon composite of claim 11, wherein, The porous carbon composite has an HK micropore volume of 0.50 to 0.75 cm 3 / g.

20. The porous carbon composite of claim 11, wherein, The microporosity of the porous carbon composite material is 60-95%.

21. The porous carbon composite of claim 11, wherein, The average pore size of the porous carbon composite material is 0.5-10 nm.

22. The porous carbon composite of claim 21, wherein, The average pore size of the porous carbon composite material is 1-10 nm.

23. The porous carbon composite of claim 22, wherein, The average pore size of the porous carbon composite material is 2-8 nm.

24. The porous carbon composite of claim 11, wherein, The D0 particle size of the porous carbon composite material is ≥0.2 μm.

25. The porous carbon composite of claim 11, wherein, The D50 of the porous carbon composite is 0.1-10 μm. 10 Particle size ≥ 2 μm.

26. The porous carbon composite of claim 11, wherein, The D50 of the porous carbon composite material is 1.0 to 10 μm. 50 The particle size is 4.0 to 11 μm.

27. The porous carbon composite of claim 11, wherein, The D50 of the porous carbon composite material is 0.5-10 μm. 90 Particle size ≤ 13 μm.

28. The porous carbon composite of claim 11, wherein, The D50 of the porous carbon composite material is 0.5-5 μm. 100 Particle size ≤ 25 μm.

29. The porous carbon composite of any one of claims 25-27, wherein, The particle size distribution of the porous carbon composite: (D 90 Particle size - D 10 Particle size) / D 50 Particle size ≤ 1.

1.

30. The porous carbon composite of claim 11, wherein, The porous carbon composite has a loose bulk density of 0.1-0.3 g / cm 3 .

31. The porous carbon composite of claim 11, wherein, The tap density of the porous carbon composite is 0.2-0.5 g / cm 3 .

32. The porous carbon composite of claim 11, wherein, The resistance of the porous carbon composite material at 20 MPa is 0-2 Ω.

33. A porous carbon material, characterized in that, The raw material for preparing the porous carbon material comprises the porous carbon composite material according to any one of claims 11-32 and an acid.

34. The porous carbon material of claim 33, wherein, The porous carbon material is prepared by a method comprising the following steps: The porous carbon composite material is subjected to acid washing to obtain the porous carbon material.

35. A silicon-carbon composite material, characterized by, The silicon-carbon composite material comprises a first silicon-carbon composite material and / or a second silicon-carbon composite material; The raw material for preparing the first silicon-carbon composite material comprises the porous carbon composite material according to any one of claims 11-32. The raw material for preparing the second silicon-carbon composite material comprises the porous carbon material according to claim 33.

36. The silicon-carbon composite of claim 35, wherein, The deposition amount of silicon in the first silicon-carbon composite material is 40%-90% of the pore volume of the first silicon-carbon composite material.

37. The silicon-carbon composite of claim 36, wherein, The deposition amount of silicon in the first silicon-carbon composite material is 60%-80% of the pore volume of the first silicon-carbon composite material.

38. The silicon-carbon composite of claim 35, wherein, The deposition amount of silicon in the second silicon-carbon composite material is 40%-90% of the pore volume of the second silicon-carbon composite material.

39. The silicon-carbon composite of claim 38, wherein, The deposition amount of silicon in the second silicon-carbon composite material is 60%-80% of the pore volume of the second silicon-carbon composite material.

40. A lithium-ion battery, characterized by, The raw material for preparing the lithium ion battery comprises at least one of the porous carbon composite material according to any one of claims 11-32, the porous carbon material according to claim 33, or the silicon-carbon composite material according to any one of claims 35-39.

Images