Metalloporphyrin covalent organic framework material and application thereof, composite solid electrolyte and preparation method thereof, and solid lithium battery

Abstract

The invention relates to the technical field of lithium ion batteries, and particularly provides a metalloporphyrin covalent organic framework material, a preparation method and application thereof, a composite solid electrolyte and a solid lithium battery. The invention aims to solve the problems that a polymer solid electrolyte in the prior art cannot stably work at room temperature due to low ionic conductivity, and the risk of generating lithium dendrites in the cycle process of a battery is increased due to high ion activation energy (0.3-0.5 eV) and low lithium ion mobility. According to the metalloporphyrin covalent organic framework material and the composite solid electrolyte based on the metalloporphyrin covalent organic framework material provided by the invention, on one hand, the ionic conductivity of a polymer solid electrolyte under a room temperature condition is improved; therefore, the problem that the lithium battery based on the polymer solid electrolyte cannot stably work at room temperature is solved; on the other hand, the activation energy of lithium ions is remarkably reduced, and the risk of generating lithium dendrites in the circulation process is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and specifically provides a metal porphyrin covalent organic framework material and its application, a composite solid electrolyte, a preparation method thereof, and a solid-state lithium battery. Background Art

[0002] Traditional liquid electrolyte lithium-ion batteries can no longer meet the market's pursuit of high energy density, wide operating temperature range, and high safety batteries. Solid electrolytes have a high electrochemical stability window and can match high-voltage cathode materials and lithium metal anodes. They are ideal electrolyte materials for the next generation of high-energy density batteries. The non-fluidity of solid electrolytes avoids the safety risks caused by leakage in traditional batteries, and their strong mechanical properties and thermal stability can inhibit the micro-short circuits caused by lithium dendrites and broaden the operating temperature range of the batteries.

[0003] Polymer solid electrolytes are an important electrolyte system for achieving high-safety and high-energy density solid-state batteries due to their good contact and compatibility with electrode materials. The conductivity of polymer solid electrolytes at room temperature is 10 -8 ~10 -7 S·cm -1 , however, the room-temperature ionic conductivity of solid electrolytes generally needs to reach 10 -4 S·cm -1 to meet commercial requirements and enable normal charging and discharging of the battery. In addition, the high ionic activation energy (0.3 - 0.5 eV) and low lithium-ion mobility of polymer solid electrolytes will increase the risk of lithium dendrite formation during battery cycling. Therefore, improving the ionic conductivity and mobility of polymer solid electrolytes at room temperature is the focus of research.

[0004] Covalent Organic Frameworks (COFs) are crystalline porous polymer materials composed of light atoms such as carbon, hydrogen, oxygen, and nitrogen, with an ordered arrangement and periodic structure. The highly ordered pore structure of COF materials can provide continuous ion transport channels, thereby improving ion mobility. Moreover, the designability of their chemical structure and topological structure allows the introduction of functional groups into the material to further improve its ionic conductivity and interfacial stability. In recent years, COF-based solid electrolyte materials for lithium batteries have received extensive attention and research.

[0005] For example, CN115312966A provides a preparation method for a covalent organic framework-based semi-solid electrolyte composite separator. However, this invention only describes the means of coating and modifying the separator with covalent organic frameworks, and the electrolyte for assembling the battery still appears in the form of an electrolyte solution, failing to achieve the purpose of improving the main problems of polymer solid electrolytes.

[0006] Shan et al. developed a series of COF-NUST-based solid electrolyte materials (Chem. Mater. 2021, 33, 5058), but their ionic conductivity was low. Even at a high temperature of 40 °C, the conductivity was only about 10 -5 S·cm -1 , and the activation energy was high (0.395 eV), resulting in difficult lithium ion migration and prone to the generation of lithium dendrite problems during cycling.

[0007] Correspondingly, a new technical solution is needed in this field to solve the above technical problems. Summary of the Invention

[0008] The present invention aims to solve the above technical problems, that is, to solve the problems that the polymer solid electrolyte in the prior art cannot work stably at room temperature due to low ionic conductivity, and the risk of lithium dendrite generation during battery cycling increases due to high ionic activation energy (0.3 - 0.5 eV) and low lithium ion mobility.

[0009] In a first aspect, the present invention provides a metal porphyrin covalent organic framework material, and the metal porphyrin covalent organic framework material has the following structure:

[0010] The wavy line indicates the connection site where the building unit extends periodically;

[0011] M1 and M2 are each independently one of transition metals.

[0012] In a preferred technical solution of the above metal porphyrin covalent organic framework material, M1 and M2 are each independently one of copper, zinc, nickel, cobalt, and iron.

[0013] In a preferred technical solution of the above metal porphyrin covalent organic framework material, at least one of M1 and M2 is cobalt or copper.

[0014] In a preferred technical solution of the above metal porphyrin covalent organic framework material, M1 and M2 are the same.

[0015] In a preferred technical solution of the above metal porphyrin covalent organic framework material, both M1 and M2 are cobalt.

[0016] In a second aspect, the present invention provides the application of the metal porphyrin covalent organic framework material as a solid electrolyte material.

[0017] In a third aspect, the present invention provides a composite solid electrolyte, wherein the composite solid electrolyte includes a solid electrolyte, PEG, and a lithium salt, and the solid electrolyte is the metal porphyrin covalent organic framework material.

[0018] In the preferred technical solution of the above composite solid electrolyte, the composite solid electrolyte is formed by introducing the PEG and the lithium salt into the pores of the metal porphyrin covalent organic framework material together.

[0019] In the preferred technical solution of the above composite solid electrolyte, the mass ratio of the metal porphyrin covalent organic framework material, PEG and the lithium salt is 1:1:(0.2 - 0.5), preferably 1:1:0.3.

[0020] In the preferred technical solution of the above composite solid electrolyte, the number average molecular weight of the PEG is 500 - 1000, preferably 600;

[0021] And / or, the lithium salt is one or more of LiTFSI, LiClO4, LiPF6, LiBF4, LiAsF6, LiBOB, LiCF3SO3, LiN(CF3SO2)2, preferably LiClO4.

[0022] In the fourth aspect, the present invention provides a preparation method of the above composite solid electrolyte, and the preparation method is as follows:

[0023] Add the metal porphyrin covalent organic framework material into an organic solution containing PEG and the lithium salt, stir and then remove the solvent, and press into tablets to obtain the product.

[0024] In the fifth aspect, the present invention provides a solid-state lithium battery, and the solid-state lithium battery includes the above composite solid electrolyte or the composite solid electrolyte prepared by the above preparation method.

[0025] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0026] 1. The metal porphyrin covalent organic framework material provided by the present invention not only has the general characteristics of crystals, shows a porous structural feature, and has a high specific surface area; but also shows a uniform and single pore structure and good stability, and the thermal stability is as high as 500 °C;

[0027] 2. The composite solid electrolyte provided by the present invention including the above metal porphyrin covalent organic framework material improves the ionic conductivity of the polymer solid electrolyte at room temperature, thereby solving the problem that the lithium battery based on the polymer solid electrolyte cannot work stably at room temperature;

[0028] 3. The composite solid electrolyte provided by the present invention including the above metal porphyrin covalent organic framework material significantly reduces the activation energy of lithium ions and greatly reduces the risk of generating lithium dendrites during the cycling process.

[0029] 4. The preparation method of the metal porphyrin covalent organic framework material of the present invention has a simple preparation process and is convenient for production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural diagram of the composite solid electrolyte based on the metal porphyrin covalent organic framework material of the present invention;

[0031] Figure 2 It is an XRD pattern of the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF obtained in Example 1;

[0032] Figure 3 It is a nitrogen adsorption diagram of the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF obtained in Example 1;

[0033] Figure 4 It is a pore size distribution diagram of the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF obtained in Example 1;

[0034] Figure 5 It is a thermogravimetric analysis diagram of the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF obtained in Example 1;

[0035] Figure 6 It is a lithium ion conduction diagram of the composite solid electrolyte based on the metal porphyrin covalent organic framework material obtained in Example 1';

[0036] Figure 7 It is an Arrhenius diagram of the composite solid electrolyte based on the metal porphyrin covalent organic framework material obtained in Example 1'. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The following describes the preferred embodiments of the present invention. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0038] In this application, the term "and / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0039] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can each be single or plural.

[0040] It should be understood that in various embodiments of this application, the magnitudes of the sequence numbers of the above processes do not imply the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0041] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0042] The weights of the relevant components mentioned in the specification of the embodiments of this application not only can refer to the specific contents of each component, but also can represent the proportional relationship of the weights between each component. Therefore, as long as the contents of the relevant components in the specification of the embodiments of this application are scaled up or down in proportion, they are within the scope disclosed in the specification of the embodiments of this application. Specifically, the mass described in the specification of the embodiments of this application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0043] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of this application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0044] The experimental methods in the following embodiments are all conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments can all be obtained from commercial channels unless otherwise specified.

[0045] Due to the problems in the prior art pointed out in the background art, the polymer solid electrolyte in the prior art cannot work stably at room temperature due to low ionic conductivity, and the risk of lithium dendrite formation increases during the cycling of the battery due to high ionic activation energy (0.3 - 0.5 eV) and low lithium ion mobility.

[0046] The present invention provides a metal porphyrin covalent organic framework material, a preparation method thereof, and a solid electrolyte. The composite solid electrolyte based on the metal porphyrin covalent organic framework material, on the one hand, improves the ionic conductivity of the polymer solid electrolyte under room temperature conditions, thereby solving the problem that the lithium battery based on the polymer solid electrolyte cannot work stably at room temperature; on the other hand, significantly reduces the activation energy of lithium ions and greatly reduces the risk of lithium dendrite formation during cycling.

[0047] Specifically, in the first aspect of the present invention, a metal porphyrin covalent organic framework material is provided, and the metal porphyrin covalent organic framework material has the following structure:

[0048] The wavy line represents the connection site where the building unit extends periodically;

[0049] M1 and M2 are each independently one of transition metals.

[0050] The metal porphyrin covalent organic framework material provided by the present invention is composed of repeating units with a quadrilateral topological structure and is formed by stacking two-dimensional planes extended by a covalent bond network through π-π interactions. The metal porphyrin covalent organic framework material has the general characteristics of crystals, exhibits a porous structural feature, and has a specific surface area as high as 860.3 m 2 ·g -1 ; at the same time, it exhibits a uniform and single pore structure, the pore structure diameter is about 1.2 nm, the pore volume is 0.36 cm 3 ·g -1 , and exhibits good thermal stability, with a thermal stability as high as 500 °C.

[0051] The composite solid electrolyte based on the metal porphyrin covalent organic framework material provided by the present invention can improve the ionic conductivity of the polymer solid electrolyte under room temperature conditions and reduce the ionic activation energy of the polymer solid electrolyte.

[0052] In the present invention, the metal porphyrin covalent organic framework material is denoted as: M1TAPP-M2TTPP-COF.

[0053] In some specific embodiments, M1 and M2 are each independently one of copper, zinc, nickel, cobalt, and iron.

[0054] It should be noted that M1 and M2 can be the same or different. For example, M1 is copper and M2 is zinc; M1 is cobalt and M2 is nickel; M1 and M2 are both copper, or any other combination.

[0055] In some specific embodiments, at least one of M1 and M2 is cobalt or copper.

[0056] As a preferred embodiment, M1 and M2 are the same.

[0057] In the present invention, when M1 and M2 are the same, the charge density distribution in the framework material is relatively more uniform, which is beneficial to promoting the transport of lithium ions in all directions. Moreover, the central metal element will attract the anionic group in the lithium salt, promoting the release of more lithium ions and accelerating the lithium ion transport rate.

[0058] As a most preferred embodiment, both M1 and M2 are cobalt.

[0059] In the present invention, when M1 and M2 are both metallic cobalt, the material exhibits the charge state that is most favorable for lithium ion transport. And the results show that the highest ion transport rate of this material is up to 5.68×10 -4 S·cm -1 .

[0060] In the present invention, the preparation method of the metal porphyrin covalent organic framework material is as follows:

[0061] Under the action of a catalyst, the metallized tetraaminophenyl porphyrin monomer shown in formula (1) and the metallized tetraaldehyde phenyl porphyrin monomer shown in formula (2) are subjected to a condensation polymerization reaction in organic solvent A to obtain the product.

[0062] In the present invention, by subjecting two monomers containing metallized porphyrin structural units to a condensation polymerization reaction, a metal porphyrin-based covalent organic framework material with a quadrilateral topological structure connected by imine bonds (-C=N-) is formed. This metal porphyrin covalent organic framework material has the general characteristics of crystals, exhibits a porous structural feature, and has a high specific surface area; at the same time, it exhibits a uniform and single pore structure and good thermal stability.

[0063] In the present invention, the process of the condensation polymerization reaction between the metallized tetraaminophenyl porphyrin monomer shown in formula (1) and the metallized tetraaldehyde phenyl porphyrin monomer shown in formula (2) is as follows:

[0064] In some specific embodiments, the metallized tetraaminophenyl porphyrin monomer is selected from at least one of copper(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, cobalt(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, nickel(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, zinc(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, and iron 5,10,15,20-tetrakis(4-aminophenyl)porphyrin.

[0065] In some specific embodiments, the metallized tetraformylphenyl porphyrin monomer is selected from one or more of copper(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin, cobalt(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin, nickel(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin, zinc(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin, and iron 5,10,15,20-tetrakis(4-formylphenyl)porphyrin.

[0066] In the present invention, the metallized tetraaminophenyl porphyrin monomer can be directly purchased from the market, can also be prepared by existing methods, or can be prepared according to the method of the present invention; the metallized tetraformylphenyl porphyrin monomer can be prepared by existing methods or can be prepared according to the method of the present invention.

[0067] In some specific embodiments, both the metallized tetraaminophenyl porphyrin monomer and the metallized tetraformylphenyl porphyrin monomer are prepared by the following method:

[0068] 5,10,15,20-Tetrakis(4-aminophenyl)porphyrin and 5,10,15,20-tetrakis(4-formylphenyl)porphyrin are respectively added to organic solvent B, and then metal salts are respectively added to the solutions obtained thereby for reaction to obtain the product.

[0069] In the present invention, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 5,10,15,20-tetrakis(4-formylphenyl)porphyrin can be commercially purchased or can be prepared.

[0070] In this application, 5,10,15,20-tetra(4-aminophenyl)porphyrin and 5,10,15,20-tetra(4-formylphenyl)porphyrin are respectively added to organic solvent B first, so that the porphyrin monomers can be fully dissolved in organic solvent B. Then, a metal salt is added to the obtained solution respectively, and after stirring, a reaction is carried out. The purpose of stirring is to make the 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer or 5,10,15,20-tetra(4-formylphenyl)porphyrin monomer mix uniformly with the metal salt and the organic solvent, ensuring that the subsequent reaction is more complete. The stirring time can be adjusted according to the actual situation. For example, the stirring time can be 6 - 12 h, but it is not limited to this range.

[0071] In some specific embodiments, the molar ratio of the metal salt to 5,10,15,20-tetra(4-aminophenyl)porphyrin or 5,10,15,20-tetra(4-formylphenyl)porphyrin is (1 - 10):1. For example, it can be 1:1, 2:1, 4:1, 6:1, 8:1, 10:1 or any value within the range of the molar ratio.

[0072] In a preferred embodiment, the molar ratio of the metal salt to 5,10,15,20-tetra(4-aminophenyl)porphyrin or 5,10,15,20-tetra(4-formylphenyl)porphyrin is 8:1.

[0073] In some specific embodiments, the reaction is carried out under the conditions of light avoidance and heating under reflux;

[0074] In a preferred embodiment, the reaction temperature is 90 - 120 °C and the reaction time is 48 - 72 h.

[0075] In some specific embodiments, the organic solvent B is a mixed solution of dimethylformamide and methanol, and the volume ratio of dimethylformamide to methanol in the mixed solution is (10 - 20):1. For example, it can be 10:1, 12:1, 14:1, 16:1, 18:1, 20:1 or any value within the range.

[0076] In the present invention, a mixed solution of dimethylformamide and methanol is used. Methanol in the mixed solution is beneficial to the dissolution of the metal salt, and dimethylformamide in the mixed solution is beneficial to the dissolution of porphyrin. The mixed solution prepared by the two is helpful for the reaction of the present invention.

[0077] In a preferred embodiment, in the mixed solution, the volume ratio of dimethylformamide to methanol is 15:1.

[0078] It should be noted that the metal salts used in the present invention are common salts in the art, and those skilled in the art can select them according to actual situations without specific limitations in this application. For example, the metal salt can be selected from one or several of copper chloride, copper sulfate, copper carbonate, copper acetate, zinc chloride, zinc sulfate, zinc carbonate, zinc acetate, nickel chloride, nickel sulfate, nickel carbonate, nickel acetate, cobalt chloride, cobalt sulfate, cobalt carbonate, cobalt acetate, iron chloride, and iron sulfate, including but not limited to these.

[0079] It should be noted that in actual applications, some conventional post-treatments are also included after the reaction, and the purpose is to obtain metallized tetra-4-formylphenylporphyrin monomers with relatively higher purity. In the present invention, the post-treatment method is not specifically limited. For example, after the reaction, the reaction solution can be cooled to room temperature and filtered to obtain a crude product, and the metallized tetra-4-formylphenylporphyrin monomer can be purified by silica gel column chromatography.

[0080] In some specific embodiments, the temperature of the condensation polymerization reaction is 100-140°C, and the time of the condensation polymerization reaction is 3-7 days.

[0081] In some specific embodiments, the molar ratio of the metallized tetra-4-aminophenylporphyrin monomer to the metallized tetra-4-formylphenylporphyrin monomer is 1:1.

[0082] In some specific embodiments, the catalyst is acetic acid.

[0083] In actual applications, acetic acid with a certain concentration can be selected according to different situations. For example, acetic acid with a concentration of 1-10 M can be selected. As a preferred method, acetic acid with a concentration of 6 M is selected.

[0084] In some specific embodiments, the organic solvent A is selected from one or several of 1,4-dioxane, mesitylene, o-dichlorobenzene, dichloromethane, chloroform, n-butanol, n-propanol, ethanol, and methanol.

[0085] It should be noted that in actual applications, the method of carrying out the condensation polymerization reaction of the metallized tetra-4-aminophenylporphyrin monomer and the metallized tetra-4-formylphenylporphyrin monomer can be carried out by conventional methods, which can be specifically adjusted according to actual situations without specific limitations in this application. For example: the metallized tetra-4-aminophenylporphyrin monomer and the metallized tetra-4-formylphenylporphyrin monomer are added to an organic solvent containing acetic acid with a certain concentration according to the molar ratio, ultrasonically dispersed and then transferred to an ampoule bottle, and the steps of liquid nitrogen freezing, vacuum pumping, and degassing are cycled, and the ampoule bottle is sealed with a flame gun; then the ampoule bottle containing the reactants and the organic solvent is placed in an oven at 120±20°C for reaction for 3-7 days.

[0086] In practical applications, the number of cycles of the steps of liquid nitrogen freezing, vacuum pumping, and degassing can be adjusted according to the actual situation. However, to ensure more complete reactions, the number of cycles is at least more than 3 times.

[0087] It should be noted that in practical applications, after the above condensation polymerization reaction, some conventional post-treatments are also included, and the purpose is to obtain reaction products with relatively higher purity. In the present invention, the method of post-treatment is not specifically limited. Specifically in the present invention, after the condensation polymerization reaction is completed, the crude product can be obtained by filtration, and the crude product is rinsed successively with ethanol, tetrahydrofuran, dichloromethane, and acetone, and then filtered by suction. The obtained product is subjected to Soxhlet extraction with tetrahydrofuran for 24 to 48 hours, and then dried in a vacuum oven to obtain the metal porphyrin covalent organic framework material.

[0088] In practical applications, during the process of drying in a vacuum oven, the vacuum degree, drying temperature, and drying time of the oven can be adjusted according to the actual situation. For example, the vacuum degree of the oven can be set to 0.1 MPa, the drying temperature can be set to 60 - 100 °C, and the drying time can be set to 12 - 24 hours.

[0089] In a second aspect of the present invention, there is provided the use of the described metal porphyrin covalent organic framework material as a solid electrolyte material.

[0090] In a third aspect of the present invention, there is provided a composite solid electrolyte, wherein the composite solid electrolyte includes a solid electrolyte, PEG, and a lithium salt, and the solid electrolyte is the described metal porphyrin covalent organic framework material.

[0091] Compared with traditional polymer solid electrolytes, the composite solid electrolyte based on metal porphyrin covalent organic framework provided by the present invention, by compounding the metal porphyrin covalent organic framework with PEG and a lithium salt, increases the lithium ion conductivity by 3 to 4 orders of magnitude (~10 -4 ), which can meet the requirements of polymer solid electrolytes for operation at room temperature. In addition, compared with the high ion activation energy (0.3 - 0.5 eV) of traditional polymer solid electrolytes, the composite solid electrolyte of the present invention significantly reduces the ion activation energy (0.14 eV), greatly reducing the risk of lithium dendrite generation during cycling.

[0092] In some specific embodiments, the composite solid electrolyte is formed by introducing the PEG and the lithium salt together into the pores of the metal porphyrin covalent organic framework material. For the structure, please refer to Figure 1 .

[0093] In the present invention, by introducing the organic molecular chain of PEG and lithium salt into the pore structure of the metal porphyrin covalent organic framework material together, a one-dimensional ion transport channel is formed in the pores. Compared with the existing solid electrolytes of covalent organic framework materials, for the composite solid electrolyte based on the metal porphyrin covalent organic framework material provided by the present invention, while the metal porphyrin covalent organic framework material provides a continuous lithium ion transport channel, the interaction between the metal atom at the porphyrin center position and the anion in the lithium salt can help release more free lithium ions and accelerate the transport of lithium ions. In addition, introducing PEG into the one-dimensional pores of the metal porphyrin covalent organic framework material can not only reduce the crystalline region of the PEG material at room temperature, but also PEG serves as a transport path for lithium ions. Under the synergistic effect of the metal porphyrin covalent organic framework and PEG, the stable operation of the polymer solid-state battery at room temperature is achieved.

[0094] In some specific embodiments, the mass ratio of the metal porphyrin covalent organic framework material, PEG and lithium salt is 1:1:0.2 - 0.5.

[0095] In a preferred embodiment, the mass ratio of the metal porphyrin covalent organic framework material, PEG and lithium salt is 1:1:0.3.

[0096] In some specific embodiments, the number average molecular weight of the PEG is 500 - 1000.

[0097] In a preferred embodiment, the number average molecular weight of the PEG is 600.

[0098] In some specific embodiments, the lithium salt is selected from one or more of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium bis(oxalato)borate (LiBOB), lithium trifluoromethanesulfonate (LiCF3SO3) and lithium bis-(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2).

[0099] In a preferred embodiment, the lithium salt is lithium perchlorate (LiClO4).

[0100] It should be noted that the present invention does not impose any restrictions on the preparation method of the composite solid electrolyte. In practical applications, those skilled in the art can select conventional methods in the art according to actual needs to prepare the composite solid electrolyte. There are adjustments and changes to the preparation method, but as long as the composite solid electrolyte described in the present invention is obtained without deviating from the basic principle of the present invention, it should be limited within the protection scope of the present invention. However, as a preferred embodiment, the present invention preferably adopts the method of the present invention for preparation. Therefore, in the fourth aspect, the present invention provides a method for preparing the composite solid electrolyte, and the method is as follows:

[0101] Add the metal porphyrin covalent organic framework material into an organic solution containing PEG and a lithium salt, stir, remove the solvent, and press into tablets to obtain the product.

[0102] In some specific embodiments, the organic solution is acetonitrile or dimethylformamide. Those skilled in the art can select according to the actual situation in practical applications.

[0103] In some specific embodiments, the stirring time is 12 to 24 h. For example, it can be 12 h, 15 h, 18 h, 20 h, 22 h, 24 h or any value within the time range. Those skilled in the art can adjust according to the actual situation in practical applications.

[0104] In a preferred embodiment, the preparation method is as follows:

[0105] Add the prepared metal porphyrin covalent organic framework material into an acetonitrile solution containing polyethylene glycol (PEG) and a lithium salt, stir for 12 to 24 hours, and then evaporate the acetonitrile solvent under normal temperature and vacuum conditions; place the obtained product under high temperature and vacuum conditions to remove residual solvent molecules, and then transfer it to a tablet press for tableting to obtain the product.

[0106] It should be noted that the process conditions of normal temperature and vacuum conditions, high temperature and vacuum conditions, and tableting in the tablet press in the above method can be adjusted according to the actual situation. For example, the normal temperature and vacuum conditions are: vacuum degree 0.1 MPa, drying temperature 20 to 30 °C, drying time 12 to 24 hours; the high temperature and vacuum conditions are: vacuum degree 0.1 MPa, drying temperature 60 to 100 °C, drying time 12 to 24 hours; the process conditions of tableting in the tablet press are: tablet press pressure 2 MPa, pressing time 10 to 30 minutes.

[0107] In the fifth aspect, the present invention provides a solid-state lithium battery, and the solid-state lithium battery includes the aforementioned composite solid electrolyte.

[0108] The following describes in detail the metal porphyrin covalent organic framework material of the present invention, its preparation method and application, the composite solid electrolyte and the solid-state lithium battery, as well as the beneficial effects brought by them through several specific embodiments.

[0109] The raw materials 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin used in the following examples were all prepared according to the following method:

[0110] I. 5,10,15,20-tetrakis(4-aminophenyl)porphyrin

[0111] Its specific synthesis route is as follows:

[0112] Specifically, it includes the following steps:

[0113] (1) Dissolve compound 1b (0.1 mmol) and acetic anhydride (0.2 mmol) in propionic acid (500 ml), and stir vigorously under argon. Dropwise add a mixture of compound 1a (0.1 mol) and propionic acid (100 ml) to the reaction mixture, and control the temperature at 120 °C. Raise the reaction temperature to 140 °C and continue stirring for 2 hours.

[0114] (2) After reacting for 2 hours, cool the system to room temperature and cool it overnight in the refrigerator. Then collect the obtained precipitate by filtration, and wash it with methanol (100 ml × 5 times) and deionized water (100 ml × 5 times). Next, dissolve the obtained dark solid in pyridine (80 ml) and reflux for 1 hour. After cooling, cool the system overnight in the refrigerator. The required purple product, namely compound 1c, was obtained by filtration, washed with a methanol / acetone mixture, and then dried under vacuum.

[0115] (3) Under an argon atmosphere, mix compound 1c (2.2 mmol) in concentrated hydrochloric acid (75 mL), and dropwise add a solution of SnCl2 (30 mmol) dissolved in concentrated hydrochloric acid (20 mL) to it. After stirring at room temperature for 3 hours, heat the reaction mixture to 80 °C and maintain it for 5 hours. After the reaction cools to room temperature, cool it to 0 °C. Then neutralize the mixture with ammonium hydroxide at 0 °C, and after obtaining the solid by vacuum filtration, disperse it in an aqueous sodium hydroxide solution (200 mL, 5%). Finally, purify the crude product with chloroform using a Soxhlet extractor to obtain compound 1d, namely 5,10,15,20-tetrakis(4-aminophenyl)porphyrin.

[0116] II. 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin

[0117] Its specific synthesis route is as follows:

[0118] Specifically, it includes the following steps:

[0119] (1) Dissolve compound 1a pyrrole (5.00 mmol) and compound 2b (5.00 mmol) in dry dichloromethane (500 mL), and purge with argon for 30 minutes. Add trifluoroacetic acid (0.386 mL, 5.00 mmol) to this solution. Under an argon atmosphere, stir the reaction mixture (protected from light) at room temperature for 2 hours. Add p-chlorobenzoquinone (0.750 mmol) to the resulting black solution all at once, and stir in a preheated water bath (45 °C) for 1.5 hours. After the reaction is cooled to room temperature, concentrate the reaction mixture under reduced pressure to 1 / 4 of its original volume. Filter the concentrated solution through a layer of deactivated neutral alumina, and elute with dichloromethane until the purple filtrate disappears. Evaporate the combined organic phases to dryness, and purify the residue by column chromatography eluting with dichloromethane to obtain compound 2c.

[0120] (2) Dissolve compound 2c (0.5 mmol) in a cold solution of dichloromethane (50 mL) and water (50 mL), add trifluoroacetic acid (50 mL), and stir at room temperature for 14 hours (protected from light) under an argon atmosphere. Monitor the completion of the reaction by 1 1H NMR spectroscopy. After the reaction is complete, dilute the reaction mixture with dichloromethane (50 mL) and water (50 mL). Separate the organic layer, and wash it with saturated aqueous potassium carbonate solution (10 ml × 3 times) and water. Separate the organic layer, dry (anhydrous potassium carbonate), and then evaporate under reduced pressure. Purify the residue by column chromatography to obtain compound 2d, namely 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin.

[0121] [Metal-porphyrin covalent organic framework material]

[0122] Example 1

[0123] The metal-porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, which is obtained by dehydration condensation through a condensation polymerization reaction of cobalt(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and cobalt(II) 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin. The specific steps are as follows:

[0124] Step 1: Provide the metallized tetraaminophenylporphyrin monomer cobalt(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and the metallized tetraformylphenylporphyrin monomer cobalt(II) 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin respectively;

[0125] (1) Cobalt(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin

[0126] Add 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (1.5 mmol) to a 50 mL mixed solution of dimethylformamide / methanol (volume ratio of dimethylformamide to methanol is 15:1), and then add cobalt acetate (3 mmol) to this solution and stir for 12 hours. Transfer the above mixed solution to a round-bottom flask, reflux and react for 48 hours at 120 °C under dark conditions, cool to room temperature and filter, wash with methanol (100 ml × 3 times) to obtain a crude product, and purify it by column chromatography with dichloromethane elution to obtain cobalt(II) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin.

[0127] (2) Cobalt(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin

[0128] Add 5,10,15,20-tetrakis(4-formylphenyl)porphyrin (1.5 mmol) to a 50 mL mixed solution of dimethylformamide / methanol (volume ratio of dimethylformamide to methanol is 15:1), and then add cobalt acetate (3 mmol) to this solution and stir for 12 hours. Transfer the above mixed solution to a round-bottom flask, reflux and react for 48 hours at 120 °C under dark conditions, cool to room temperature and filter, wash with methanol (100 ml × 3 times) to obtain a crude product, and purify it by column chromatography with dichloromethane elution to obtain cobalt(II) 5,10,15,20-tetrakis(4-formylphenyl)porphyrin.

[0129] Step 2: Under the action of a catalyst, carry out a condensation polymerization reaction of metallized tetraaminophenylporphyrin monomer and metallized tetraformylphenylporphyrin monomer in organic solvent A to obtain CoTAPP-CoTTPP-COF; specifically as follows:

[0130] 5,10,15,20-Tetrakis(4-aminophenyl)porphyrin cobalt(II) (20 mmol) and 5,10,15,20-tetrakis(4-formylphenyl)porphyrin cobalt(II) (20 mmol) monomer materials were added to a mixed solution containing 0.1 ml of acetic acid (6 M), 0.5 ml of 1,4-dioxane and 0.5 ml of n-butanol. The above mixed solution was ultrasonically dispersed and then transferred to a 10-ml ampoule bottle. The steps of liquid nitrogen freezing, vacuum pumping and degassing were cycled, and the ampoule bottle was sealed with a flame gun. The ampoule bottle containing the reactants and solvents was placed in an oven at 120 °C for 3 days. After filtering to obtain the crude product, it was rinsed successively with ethanol, tetrahydrofuran, dichloromethane and acetone, and then filtered by suction. The obtained product was extracted with tetrahydrofuran in a Soxhlet extractor for 48 hours and dried in a vacuum oven to obtain the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF.

[0131] The prepared metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF was subjected to X-ray diffraction testing, and its XRD pattern is as shown in Figure 2 shown. Figure 2 The results show that the metal porphyrin covalent organic framework material presents an ordered crystal structure.

[0132] The prepared metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF was subjected to nitrogen adsorption testing, and its nitrogen adsorption graph is as shown in Figure 3 shown. Figure 3 The results show that the metal porphyrin covalent organic framework material exhibits porous structural characteristics, and the specific surface area is as high as 860.3 m 2 ·g -1 .

[0133] The prepared metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF was subjected to pore size testing, and its pore size distribution graph is as shown in Figure 4 shown. Figure 4 The results show that the metal porphyrin covalent organic framework material exhibits a uniform and single pore structure. The diameter of the pore structure is about 1.2 nm, and the pore volume is 0.36 cm 3 ·g -1 .

[0134] The prepared metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF was subjected to thermogravimetric analysis testing, and its thermogravimetric analysis graph is as shown in Figure 5 shown. Figure 5 The results show that the metal porphyrin covalent organic framework material exhibits good thermal stability, and the thermal stability is as high as 500 °C.

[0135] Example 2

[0136] The metal porphyrin covalent organic framework material provided in this example is CuTAPP-CuTTPP-COF. Its preparation method is basically the same as that of Example 1, except that:

[0137] In step 1, copper(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and copper(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided. The preparation method is to replace cobalt acetate used in Example 1 with copper acetate.

[0138] The reactants used in step 2 are copper(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and copper(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0139] Example 3

[0140] The metal porphyrin covalent organic framework material provided in this example is NiTAPP-NiTTPP-COF. Its preparation method is basically the same as that of Example 1, except that:

[0141] In step 1, nickel(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and nickel(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided. The preparation method is to replace cobalt acetate used in Example 1 with nickel acetate.

[0142] The reactants used in step 2 are nickel(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and nickel(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0143] Example 4

[0144] The metal porphyrin covalent organic framework material provided in this example is ZnTAPP-ZnTTPP-COF. Its preparation method is basically the same as that of Example 1, except that:

[0145] In step 1, zinc(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and zinc(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided. The preparation method is to replace cobalt acetate used in Example 1 with zinc acetate.

[0146] The reactants used in step 2 are zinc(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and zinc(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0147] Example 5

[0148] The metal porphyrin covalent organic framework material provided in this example is FeTAPP-FeTTPP-COF, and its preparation method is basically the same as that of Example 1, except that:

[0149] In step 1, iron(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and iron(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided, and the preparation method is to replace cobalt acetate used in Example 1 with iron chloride.

[0150] The reactants used in step 2 are iron(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and iron(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0151] Example 6

[0152] The metal porphyrin covalent organic framework material provided in this example is CuTAPP-ZnTTPP-COF, and its preparation method is basically the same as that of Example 1, except that:

[0153] In step 1, copper(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and zinc(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided, and the preparation method is to replace cobalt acetate used in step (1) of Example 1 with copper acetate, and replace cobalt acetate used in step (2) of Example 1 with zinc acetate.

[0154] The reactants used in step 2 are copper(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and zinc(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0155] Example 7

[0156] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-NiTTPP-COF, and its preparation method is basically the same as that of Example 1, except that:

[0157] In step 1, cobalt(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and nickel(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin are provided, and the preparation method is to replace cobalt acetate used in step (2) of Example 1 with nickel acetate.

[0158] The reactants used in step 2 are cobalt(II) 5,10,15,20-tetra(4-aminophenyl)porphyrin and nickel(II) 5,10,15,20-tetra(4-formylphenyl)porphyrin.

[0159] Example 8

[0160] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the molar ratio of cobalt acetate to 5,10,15,20-tetra(4-aminophenyl)porphyrin or 5,10,15,20-tetra(4-formylphenyl)porphyrin in Step 1 is 1:1.

[0161] Example 9

[0162] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the molar ratio of cobalt acetate to 5,10,15,20-tetra(4-aminophenyl)porphyrin or 5,10,15,20-tetra(4-formylphenyl)porphyrin in Step 1 is 10:1.

[0163] Example 10

[0164] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the reaction temperature in Step 1 is 90 °C and the reaction time is 72 h.

[0165] Example 11

[0166] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the volume ratio of dimethylformamide to methanol in Step 1 is 10:1.

[0167] Example 12

[0168] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the volume ratio of dimethylformamide to methanol in Step 1 is 20:1.

[0169] Example 13

[0170] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that in Example 1. The difference from Example 1 is that the oven temperature in Step 2 is 100 °C and the reaction time is 7 days.

[0171] Example 14

[0172] The metal porphyrin covalent organic framework material provided in this example is CoTAPP-CoTTPP-COF, and its preparation method is the same as that of Example 1. The difference from Example 1 is that in Step 2, the oven temperature is 140 °C and the reaction time is 4 days.

[0173] [Composite solid electrolyte]

[0174] Example 1'

[0175] 30 mg of the metal porphyrin covalent organic framework material CoTAPP-CoTTPP-COF prepared in Example 1 was added to 1 ml of acetonitrile solution containing 30 mg of PEG (number average molecular weight of 600) and 9 mg of LiClO4. After stirring for 24 hours, the solvent in the system was evaporated and removed under normal temperature and vacuum (0.1 MPa) conditions. The obtained product was placed under vacuum (0.1 MPa) conditions at 90 °C to remove residual solvent molecules. Then the material was transferred to a tablet press for tableting, and pressed for 30 minutes under a pressure of 2 MPa to obtain a self-supporting composite solid electrolyte membrane based on the metal porphyrin covalent organic framework material.

[0176] For the structure of the obtained composite solid electrolyte membrane, please refer to Figure 1 . As Figure 1 shown, the organic molecular chains of PEG and the lithium salt are jointly introduced into the pore structure of the metal porphyrin covalent organic framework material to form a one-dimensional ion transport channel in the pores.

[0177] The following are Examples 2' to 11' of the composite solid electrolyte. The preparation method refers to Example 1'. The difference from Example 1' is that the metal porphyrin covalent organic framework materials used in each example (denoted as: M1TAPP-M2TTPP-COF), the mass ratio of the metal porphyrin covalent organic framework material to PEG and lithium salt, and the number average molecular weight of the PEG used are different. The specific details are shown in Table 1. For the convenience of comparison with each other, the metal porphyrin covalent organic framework material, the mass ratio of the metal porphyrin covalent organic framework material to PEG and lithium salt, and the molecular weight of the PEG used in Example 1' are also listed in Table 1.

[0178] Table 1. Examples of Composite Solid Electrolytes

[0179] [Solid-state lithium battery]

[0180] The composite solid electrolytes obtained in the above examples can be used to prepare solid-state lithium batteries according to the following method:

[0181] First, prepare a negative electrode case, place a shrapnel, place a gasket, place a 14-mm lithium sheet, respectively place the composite solid electrolytes obtained in each embodiment, then place a 12-mm lithium iron phosphate (LFP), cover the positive electrode case, and put it into a button battery encapsulation machine to complete the encapsulation, thus obtaining the product.

[0182] Test Example 1

[0183] This test example investigated the performance of the composite solid electrolytes prepared in each embodiment.

[0184] 1. Ionic conductivity

[0185] The ionic conductivity of the composite solid electrolyte was tested by the alternating current impedance method. The instrument used was a Hioki model IM3570 impedance analyzer. The sample to be tested was assembled into a simulated button battery in the order of stainless steel electrode / composite solid electrolyte prepared in Example 1' / stainless steel electrode in a glove box filled with argon, and then the alternating current impedance test was carried out on this simulated battery at 25°C. Before the test, the simulated battery was kept at a constant temperature for 1 h at each temperature point, and the test was carried out under the conditions of a frequency range of 4 Hz to 5 MHz and an input voltage amplitude of 100 mV, and the EIS curve was recorded. The test results are shown in Figure 6 . The ionic conductivity of the composite solid electrolyte was obtained through calculation. The formula for ionic conductivity is as follows: σ = l / (R×A)

[0186] Where:

[0187] l - the thickness of the composite solid electrolyte membrane, in cm;

[0188] R - the resistance obtained from the impedance diagram, in Ω;

[0189] A - the contact area between the solid electrolyte and the electrode, in cm 2 .

[0190] From Figure 6 the test data, it can be calculated that the composite solid electrolyte exhibits a conductivity of 5.68×10 -4 S·cm -1 at 30°C. Compared with traditional polymer solid electrolyte materials (10 -8 ~10 -7 S·cm -1 ), it is improved by 3 to 4 orders of magnitude.

[0191] 2. Ionic activation energy

[0192] The ionic conductivity σ measured at different temperatures in "1. Ionic Conductivity" is used to calculate the activation energy Ea of the composite solid electrolyte in Example 1'. Plot ln(σ) against 1 / T, and perform linear regression by the least squares method to obtain a fitting line, as shown in Figure 7 shown. According to the Arrhenius equation:

[0193] where R is the gas constant, T is the temperature (unit: Kelvin), and A is the pre-exponential factor. It can be seen that the slope of this fitting curve is -Ea / R, and the activation energy of this composite solid electrolyte is calculated based on the slope.

[0194] From the Figure 7 test data, it can be calculated that this composite solid electrolyte exhibits an ionic activation energy of 0.14 eV, which is much lower than that of traditional polymer solid electrolyte materials (0.3 - 0.5 eV). The lower ionic activation energy is beneficial to the migration of lithium ions and reduces the lithium dendrites generated due to uneven current density distribution.

[0195] The above tests were also carried out on the composite solid electrolytes prepared in other examples, and the results are shown in Table 2.

[0196] Table 2

[0197] From the above test examples, it can be seen that for the composite solid electrolyte based on the metal porphyrin covalent organic framework material of the present invention, on the one hand, it improves the ionic conductivity of the polymer solid electrolyte at room temperature, thus solving the problem that lithium batteries based on polymer solid electrolytes cannot work stably at room temperature; on the other hand, it significantly reduces the activation energy of lithium ions and greatly reduces the risk of generating lithium dendrites during the cycling process.

[0198] So far, the technical solutions of the present invention have been described in combination with the preferred embodiments. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A metal porphyrin covalent organic framework material, characterized in that The metal porphyrin covalent organic framework material has the following structure: The wavy line represents the connection site for the periodic extension of the building unit; M1 and M2 are each independently one of the transition metals.

2. The metal porphyrin covalent organic framework material according to claim 1, wherein M1 and M2 are each independently one of copper, zinc, nickel, cobalt, and iron.

3. The metal porphyrin covalent organic framework material according to claim 2, characterized in that, At least one of M1 and M2 is cobalt or copper.

4. The metalloporphyrin covalent organic framework material according to any one of claims 1-3, characterized in that M1 and M2 are the same.

5. The metal porphyrin covalent organic framework material according to claim 4, characterized in that, Both M1 and M2 are cobalt.

6. Use of the metal porphyrin covalent organic framework material according to any one of claims 1-5 as a solid electrolyte material.

7. A composite solid electrolyte, characterized in that, The composite solid electrolyte includes a solid electrolyte, PEG, and a lithium salt, and the solid electrolyte is the metal porphyrin covalent organic framework material according to any one of claims 1-5.

8. The composite solid electrolyte according to claim 7, wherein The composite solid electrolyte is formed by introducing the PEG and the lithium salt together into the pores of the metal porphyrin covalent organic framework material.

9. The composite solid electrolyte according to claim 7 or 8, characterized in that, The mass ratio of the metal porphyrin covalent organic framework material, PEG, and the lithium salt is 1:1:(0.2-0.5), more preferably 1:1:0.

3.

10. The composite solid electrolyte according to claim 9, wherein The number average molecular weight of the PEG is 500-1000, preferably 600; And / or, the lithium salt is one or more of LiTFSI, LiClO4, LiPF6, LiBF4, LiAsF6, LiBOB, LiCF3SO3, LiN(CF3SO2)2, preferably LiClO4.

11. A method for preparing the composite solid electrolyte according to any one of claims 7-10, characterized in that, The preparation method is as follows: Add the metal porphyrin covalent organic framework material to an organic solution containing PEG and a lithium salt, stir, remove the solvent, and press into tablets to obtain the product.

12. A solid-state lithium battery, characterized in that, The solid-state lithium battery includes the composite solid electrolyte according to any one of claims 7-10 or the composite solid electrolyte prepared by the preparation method according to claim 11.

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