Preparation method for in-situ growth of conductive Cu-based MOF on copper current collector and application thereof

Abstract

The invention discloses a preparation method for in-situ growth of a conductive Cu-based MOF on a copper current collector and application thereof, and the preparation method comprises the following steps: mixing a sodium hydroxide solution and an ammonium persulfate solution, placing the copper current collector in the obtained mixed solution to obtain the copper current collector with a copper hydroxide nanowire grown on the surface, and carrying out in-situ growth of the conductive Cu-based MOF on the copper current collector to obtain the conductive Cu-based MOF. The preparation method comprises the following steps: preparing a copper current collector, placing the copper current collector in a ligand solution obtained by dissolving HHTP or HITP.6HCl in a solvent, reacting at 60-70 DEG C, cleaning and drying the copper current collector after the reaction is completed, and then activating at 100-200 DEG C to obtain the copper current collector on which the conductive Cu-based MOF grows in situ. The conductive Cu-MOFs constructed on the surface of the copper current collector in situ are generated through reaction in the solution, the reaction condition is mild, the preparation process is simple, coating after slurry preparation is not needed, the preparation period is short, the problem that large-scale preparation cannot be carried out can be solved, and commercialization is expected to be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal organic framework material preparation, and in particular to a preparation method for in-situ growing a conductive Cu-based MOF on a copper current collector and its application. Background Art

[0002] With the continuous advancement of science and technology, society's demand for energy is growing. Traditional non-renewable energy sources, such as oil and natural gas, can cause serious environmental pollution through overexploitation and utilization. While environmentally friendly, renewable energy sources like wind and solar power have limitations that prevent direct utilization. Therefore, the development of reliable energy storage devices has become a key issue in the energy sector.

[0003] Currently, lithium metal batteries with graphite as the negative electrode and lithium iron phosphate and ternary materials as the positive electrode have encountered a bottleneck in performance improvement due to the low theoretical specific capacity (372mAh / g) of the graphite negative electrode. In recent years, lithium metal has been widely used due to its low redox potential (-3.04V vs. SHE) and high theoretical energy (3860mAh g -1 ), has received widespread attention in the energy storage field. However, its commercialization faces numerous obstacles, particularly the high nucleation barrier of lithium metal anodes, which can cause the growth of lithium dendrites, piercing the separator and causing battery short circuits, as well as serious safety issues such as volume expansion. Therefore, the development of lithium-philic three-dimensional current collectors has become a research focus in the lithium metal battery field.

[0004] At present, most commercial current collectors use copper foil, which is due to the good ductility, electronic conductivity, and excellent thermal stability of copper at low voltage. In addition, its preparation process is mature and the cost is low. However, the existing commercial copper current collectors with (111) and (110) crystal planes have a high lithium deposition barrier, which will cause lithium to be deposited unevenly on its surface, forming an uneven solid electrolyte interface layer and lithium dendrites during the deposition process. This will not only increase the battery impedance, but may also cause the battery to short-circuit due to lithium dendrites piercing the diaphragm. At the same time, the "dead" lithium formed after the lithium dendrites fall off will reduce the battery coulombic efficiency, seriously hindering the large-scale application of lithium metal negative electrodes. The lithium-philic three-dimensional copper current collector can effectively reduce the nucleation overpotential of lithium, uniform lithium flux, reduce the formation of dendrites and "dead" lithium, and thus improve the electrochemical performance of the battery.

[0005] To alleviate the problem of uneven lithium deposition, the use of porous three-dimensional host frameworks has become a research direction. Metal-organic framework materials have been widely studied in the field of lithium batteries due to their porous structure. However, there are currently many problems with this type of material: First, the synthesis cycle of most metal-organic framework materials is long, and the material uniformity is poor during large-scale preparation. The preparation process requires synthesizing sufficient materials in a short period of time, then preparing slurry for coating, and drying in a vacuum environment. This has high requirements for equipment and environment, and mechanical stirring or ball milling is time-consuming. Second, most metal-organic framework materials used in copper current collectors are not conductive and require the addition of conductive agents such as Ketjen black or carbon black, which will reduce the energy density of lithium metal batteries. In addition, although some carbon materials and inorganic materials are also used for current collector modification, the preparation conditions of carbon materials are harsh, the specific surface area is small, the pore structure is difficult to control, and there is a lack of lithium-philic sites, which is not conducive to reducing the nucleation sites of lithium ions. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a preparation method and application of in-situ growth of a conductive Cu-based MOF on a copper current collector.

[0007] The present invention is achieved through the following technical solutions:

[0008] The first aspect of the present invention provides a preparation method for in-situ growing a conductive Cu-based MOF on a copper current collector, comprising the following steps:

[0009] (1) mixing a sodium hydroxide (NaOH) solution and an ammonium persulfate ((NH4)2S2O8) solution to obtain a mixed solution; placing a copper current collector in the mixed solution to obtain a copper current collector having copper hydroxide nanowires grown on the surface;

[0010] (2) dissolving 2,3,6,7,10,11-hexahydroxytriphenylenebenzene (HHTP) or 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride (HITP·6HCl) in a solvent to obtain a ligand solution; placing the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) in the ligand solution, reacting at 60-70° C., washing and drying the copper current collector after the reaction, and then activating it at 100-200° C. to obtain a copper current collector with in-situ growth of a conductive Cu-based MOF.

[0011] The conductive Cu-MOFs (CuHHTP or CuHITP) constructed in situ on the surface of the copper current collector of the present invention are generated by reaction in solution. By the impregnation method, copper hydroxide is converted into Cu-MOFs in a relatively short time. It has good uniformity, mild reaction conditions and simple preparation process, which can solve the problem of large-scale preparation and is expected to be commercialized.

[0012] Furthermore, in step (1), the copper current collector is treated to remove surface impurities and to be dried.

[0013] Specifically, in step (1), the copper current collector is cleaned with acetone, ethanol, and water to remove impurities such as grease and oxides on the surface and then dried.

[0014] Furthermore, in step (1), the concentration of sodium hydroxide in the sodium hydroxide solution is 3-4 mol / L, the concentration of ammonium persulfate in the ammonium persulfate solution is 0.1-0.2 mol / L, and the volume ratio of the sodium hydroxide solution to the ammonium persulfate solution is 1:(0.8-1.2).

[0015] Specifically, in step (1), sodium hydroxide is dissolved in water to obtain a sodium hydroxide aqueous solution, ammonium persulfate is dissolved in water to obtain an ammonium persulfate aqueous solution, the sodium hydroxide aqueous solution and the ammonium persulfate aqueous solution are mixed, and stirred in a closed container for 1.5-2.5 hours to obtain a mixed solution.

[0016] Furthermore, in step (1), the copper current collector is placed in the mixed solution for 10-30 minutes.

[0017] Specifically, in step (1), the copper current collector is placed in the mixed solution for 10-30 minutes, taken out, cleaned and dried to obtain a copper current collector with copper hydroxide nanowires grown on the surface.

[0018] The present invention uses copper hydroxide as Cu 2+ source, and copper hydroxide also exists as a three-dimensional host framework, which can alleviate the volume expansion.

[0019] The growth density and length of the copper hydroxide nanowires prepared in the present invention depend on the concentrations of the sodium hydroxide solution and ammonium persulfate solution, as well as the immersion time of the copper current collector in the mixed solution. When the mixed solution concentration is too high, the reaction produces a spherical structure, which is not conducive to the growth of a nanowire structure. When the mixed solution concentration is too low, the reaction time is too long. The growth density and length of the copper hydroxide nanowires further affect the density of the conductive Cu-MOFs (CuHHTP or CuHITP). Therefore, in commercialization, the density of the conductive Cu-MOFs (CuHHTP or CuHITP) can be further adjusted by adjusting the copper hydroxide nanowires.

[0020] Furthermore, in step (2), the solvent is a mixed solvent of N,N-dimethylformamide (DMF) and water or a mixed solvent of N,N-dimethylacetamide (DMA) and water.

[0021] Furthermore, in step (2), HHTP is dissolved in a mixed solvent of DMF and water to obtain a ligand solution; the concentration of HHTP in the ligand solution is 0.4-1 mg / mL, preferably 0.4-0.6 mg / mL, preferably 0.5 mg / mL.

[0022] Furthermore, the volume ratio of DMF to water is 1:(8-12), preferably 1:10.

[0023] Furthermore, in step (2), HITP·6HCl is dissolved in a mixed solvent of DMA and water to obtain a ligand solution; the concentration of HITP·6HCl in the ligand solution is 0.4-1 mg / mL, preferably 0.4-0.6 mg / mL, and more preferably 0.5 mg / mL.

[0024] Furthermore, the volume ratio of DMA to water is 1:(0.5-1.5), preferably 1:1.

[0025] The preparation method provided by the present invention is universal, and the structure of the conductive metal-organic framework material formed is variable. Using the same method, one-dimensional rod-shaped CuHHTP can be in situ grown on copper hydroxide nanowires using HHTP, and two-dimensional sheet-like CuHITP can be in situ grown on copper hydroxide nanowires using HITP·6HCl. This can effectively solve the problem of the material's small specific surface area and its disadvantage for the storage of metallic lithium.

[0026] Furthermore, in step (2), the copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) is placed in the ligand solution and reacted in an oil bath at 60-70° C. for 10-30 minutes, preferably 10-20 minutes.

[0027] Specifically, in step (2), the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) is placed in the ligand solution, reacted in an oil bath at 60-70°C for 10-20 minutes, the copper current collector after the reaction is completed is cleaned and dried, and then placed in a tube furnace for activation treatment at 100-200°C for 1.5-2.5 hours to obtain a copper current collector with in-situ growth of a conductive Cu-based MOF.

[0028] The second aspect of the present invention provides a copper current collector having a conductive Cu-based MOF grown in situ, which is prepared by the preparation method described in the first aspect.

[0029] The third aspect of the present invention provides the use of the copper current collector with in-situ growth of a conductive Cu-based MOF as described in the second aspect in a lithium metal battery.

[0030] Furthermore, the copper current collector with the in-situ growth of the conductive Cu-based MOF is made into an electrode sheet for assembling a lithium metal battery.

[0031] The ether electrolyte has a good wetting effect on the electrode sheet prepared by the present invention, which is mainly due to the fact that the in-situ converted CuHHTP@Cu(OH)2 and CuHITP@Cu(OH)2 have a larger space.

[0032] The beneficial effects of the present invention are:

[0033] 1. The conductive Cu-MOFs (CuHHTP or CuHITP) constructed in situ on the surface of the copper current collector of the present invention are generated by reaction in solution. The reaction conditions are mild, the preparation process is simple, and no slurry preparation and subsequent coating are required. The preparation cycle is short, which can solve the problem of large-scale preparation and is expected to be commercialized.

[0034] 2. The conductive Cu-MOFs grown in situ on the surface of the copper current collector in the present invention have better conductivity than most metal-organic framework materials, and the electrochemical performance proves that this structure can more effectively achieve lithium deposition / stripping behavior without dendrite generation.

[0035] 3. The present invention uses an in-situ preparation method and utilizes the inherent conductive properties of conductive Cu-MOFs (CuHHTP or CuHITP) to reduce the use of conductive agents and binders when assembling lithium metal batteries, which is beneficial to improving the energy density of the negative electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the preparation method of the present invention for in-situ growth of a conductive Cu-based MOF on a copper current collector.

[0037] Figure 2 Schematic diagrams of the contact angles of ether electrolyte on commercial copper current collector and CuHHTP@Cu prepared in Example 1, respectively; wherein, a) is commercial copper current collector, and b) is CuHHTP@Cu.

[0038] Figure 3 These are SEM images of CuHHTP prepared in Example 1 and CuHITP prepared in Example 2; wherein a) is the SEM image of CuHHTP, and b) is the SEM image of CuHITP.

[0039] Figure 4 These are the XRD patterns of CuHHTP@Cu prepared in Example 1 and CuHITP@Cu prepared in Example 2; wherein, a) is the XRD pattern of CuHHTP@Cu, and b) is the XRD pattern of CuHITP@Cu.

[0040] Figure 5 These are SEM images of CuHITP prepared in Examples 2-7; wherein a is Example 2, b is Example 3, c is Example 4, d is Example 5, e is Example 6, and f is Example 7.

[0041] Figure 6 This is a graph showing the long cycle performance test results of a half-cell assembled with a commercial copper current collector and CuHHTP@Cu prepared in Example 1 and lithium foil.

[0042] Figure 7 This is a graph showing the long cycle performance test results of the button battery assembled with CuHITP@Cu and lithium foil prepared in Example 2-7. DETAILED DESCRIPTION

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] The present invention provides a preparation method for in-situ growing a conductive Cu-based MOF on a copper current collector, comprising the following steps:

[0045] (1) mixing a sodium hydroxide (NaOH) solution and an ammonium persulfate ((NH4)2S2O8) solution to obtain a mixed solution; placing a copper current collector in the mixed solution to obtain a copper current collector having copper hydroxide nanowires grown on the surface;

[0046] (2) dissolving 2,3,6,7,10,11-hexahydroxytriphenylenebenzene (HHTP) or 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride (HITP·6HCl) in a solvent to obtain a ligand solution; placing the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) in the ligand solution, reacting at 60-70° C., washing and drying the copper current collector after the reaction, and then activating it at 100-200° C. to obtain a copper current collector with in-situ growth of a conductive Cu-based MOF.

[0047] Figure 1 Schematic diagram of the preparation method of the present invention for in-situ growth of a conductive Cu-based MOF on a copper current collector.

[0048] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0049] The following examples utilize conventional instruments and equipment in the art. Experimental procedures in the following examples, where specific conditions are not specified, generally follow conventional conditions or those recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, are conventional commercially available products, with specifications conventional in the art.

[0050] Example 1

[0051] A preparation method for in-situ growth of a conductive Cu-based MOF (CuHHTP) on a copper current collector comprises the following steps:

[0052] (1) Weigh 28.442 g of sodium hydroxide and dissolve it in 200 mL of deionized water to obtain a sodium hydroxide solution with a concentration of 3.555 mol / L. Weigh 8.1136 g of ammonium persulfate and dissolve it in 200 mL of deionized water to obtain an ammonium persulfate solution with a concentration of 0.1778 mol / L. The sodium hydroxide solution and the ammonium persulfate solution are mixed and stirred in a closed container for 2 h to obtain a mixed solution.

[0053] A 40 μm thick copper current collector was placed in acetone, ethanol, and deionized water in turn, and ultrasonicated for 2 minutes each to wash away impurities such as grease and oxide layer on the surface, and then placed in a vacuum oven at 60°C for drying.

[0054] The treated copper current collector was placed in the mixed solution for 20 minutes, taken out and washed with a large amount of deionized water, and then dried in a vacuum oven at 60° C. to obtain a copper current collector with copper hydroxide nanowires grown on the surface.

[0055] (2) DMF and water were mixed at a volume ratio of 1:10 to obtain a mixed solvent. 5 mg of HHTP was dissolved in 10 mL of the mixed solvent and stirred for 30 min to obtain a HHTP solution with a concentration of 0.5 mg / mL.

[0056] The copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) is placed in a HHTP solution, the above solution is placed in an oil bath at 65°C, and reacted for 10 minutes under magnetic stirring. After taking it out, the residual solution on the surface of the copper current collector is rinsed with deionized water, and it is placed in a vacuum oven at 60°C for drying. Then, it is placed in a tube furnace and heated at 150°C for 2 hours to discharge the solution, gas, etc. in the pores to obtain a copper current collector (CuHHTP@Cu) with in situ growth of a conductive Cu-based MOF (CuHHTP).

[0057] Figure 2Schematic diagrams of the contact angles of an ether electrolyte on a commercial copper current collector (40 μm thick) and the CuHHTP@Cu prepared in Example 1. (a) shows the commercial copper current collector, and (b) shows the CuHHTP@Cu. The ether electrolyte solvents are 1,3-dioxolane (DOL) and ethylene glycol dimethyl ether (DME), with a DOL:DME volume ratio of 1:1. The ether electrolyte contains 1 M lithium bis(trifluoromethanesulfonyl imide) (LiTFSI) and 5 wt% of the electrolyte additive LiNO3.

[0058] Example 2

[0059] A preparation method for in-situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector comprises the following steps:

[0060] (1) Weigh 28.442 g of sodium hydroxide and dissolve it in 200 mL of deionized water to obtain a sodium hydroxide solution with a concentration of 3.555 mol / L. Weigh 8.1136 g of ammonium persulfate and dissolve it in 200 mL of deionized water to obtain an ammonium persulfate solution with a concentration of 0.1778 mol / L. The sodium hydroxide solution and the ammonium persulfate solution are mixed and stirred in a closed container for 2 h to obtain a mixed solution.

[0061] A 40 μm thick copper current collector was placed in acetone, ethanol, and deionized water in turn, and ultrasonicated for 2 minutes each to wash away impurities such as grease and oxide layer on the surface, and then placed in a vacuum oven at 60°C for drying.

[0062] The treated copper current collector was placed in the mixed solution for 20 minutes, taken out and washed with a large amount of deionized water, and then dried in a vacuum oven at 60° C. to obtain a copper current collector with copper hydroxide nanowires grown on the surface.

[0063] (2) DMA and water were mixed in a volume ratio of 1:1 to obtain a mixed solvent. 5 mg of HITP·6HCl was dissolved in 10 mL of the mixed solvent and stirred for 10 min to obtain a HITP·6HCl solution with a concentration of 0.5 mg / mL.

[0064] The copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) is placed in a HITP·6HCl solution, the above solution is placed in an oil bath at 65°C, and reacted for 10 minutes under magnetic stirring. After being taken out, the residual solution on the surface of the copper current collector is rinsed off with deionized water, and the copper current collector is placed in a vacuum oven at 60°C for drying. Then, it is placed in a tube furnace and heated at 150°C for 2 hours to discharge the solution, gas, etc. in the pores to obtain a copper current collector (CuHITP@Cu) with in situ growth of a conductive Cu-based MOF (CuHITP).

[0065] Figure 3 The following are scanning electron microscope (SEM) images of CuHHTP prepared in Example 1 and CuHITP prepared in Example 2; wherein a) is the SEM image of CuHHTP, and b) is the SEM image of CuHITP. Figure 3 It can be seen that CuHHTP has a nanorod structure and CuHITP has a nanosheet structure.

[0066] Figure 4 X-ray diffractometer (XRD) patterns of CuHHTP@Cu prepared in Example 1 and CuHITP@Cu prepared in Example 2; wherein, a) is the XRD pattern of CuHHTP@Cu, and b) is the XRD pattern of CuHITP@Cu.

[0067] Example 3

[0068] A preparation method for in-situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector is basically the same as Example 2, except that: in step (2), the copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) is placed in a HITP·6HCl solution, the solution is placed in an oil bath at 65°C, and a magnetic stirrer is added to react for 20 minutes.

[0069] Example 4

[0070] A preparation method for in-situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector is basically the same as Example 2, except that: in step (2), the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) is placed in a HITP·6HCl solution, the solution is placed in an oil bath at 65°C, and a magnetic stirrer is added to react for 30 minutes.

[0071] Example 5

[0072] A preparation method for in situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector is substantially the same as that of Example 2, except that in step (2), DMA and water are mixed in a volume ratio of 1:1 to obtain a mixed solvent, 10 mg of HITP·6HCl is dissolved in 10 mL of the mixed solvent, and the mixture is stirred for 10 min to obtain a HITP·6HCl solution with a concentration of 1 mg / mL.

[0073] Example 6

[0074] A preparation method for in situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector is substantially the same as that of Example 2, except that in step (2), DMA and water are mixed in a volume ratio of 1:1 to obtain a mixed solvent, 10 mg of HITP·6HCl is dissolved in 10 mL of the mixed solvent, and the mixture is stirred for 10 min to obtain a HITP·6HCl solution with a concentration of 1 mg / mL.

[0075] The copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) was placed in a HITP·6HCl solution, and the solution was placed in an oil bath at 65° C., and reacted for 20 minutes under stirring with a magnetic stirrer.

[0076] Example 7

[0077] A preparation method for in situ growth of a conductive Cu-based MOF (CuHITP) on a copper current collector is substantially the same as that of Example 2, except that in step (2), DMA and water are mixed in a volume ratio of 1:1 to obtain a mixed solvent, 10 mg of HITP·6HCl is dissolved in 10 mL of the mixed solvent, and the mixture is stirred for 10 min to obtain a HITP·6HCl solution with a concentration of 1 mg / mL.

[0078] The copper current collector with copper hydroxide nanowires grown on its surface obtained in step (1) was placed in a HITP·6HCl solution, and the solution was placed in an oil bath at 65° C., and reacted for 30 minutes under stirring with a magnetic stirrer.

[0079] Figure 5 The SEM images of CuHITP prepared in Examples 2-7 are shown; a is Example 2, b is Example 3, c is Example 4, d is Example 5, e is Example 6, and f is Example 7. Figure 5 It can be seen that different ligand concentrations and immersion time affect the morphology of CuHITP and the density of CuHITP nanosheets, and the nanosheets are easy to fall off after excessive reaction.

[0080] Test Example 1

[0081] The commercial copper current collector or the CuHHTP@Cu prepared in Example 1 was punched into a disc-shaped electrode sheet with a diameter of 13 mm as the positive electrode. 1,3-dioxolane (DOL) and ethylene glycol dimethyl ether (DME) with a volume ratio of 1:1 were used as solvents to prepare an ether electrolyte containing 1M electrolyte lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 5wt% electrolyte additive lithium nitrate (LiNO3). A half-cell was assembled with lithium foil as the negative electrode for electrochemical testing. The test method was as follows: the half-cell was left to rest for two hours, then activated with a small current of 0.05 mA, first discharged to 0 V at a constant current, then charged to 1 V, and cycled 4 times. At 1 mA·cm -2 The current density was 1mA·cm -2 The battery was charged to 1 V at a current density of 100 nm and cycled.

[0082] The test results are as follows Figure 6 As shown, Figure 6 The long cycle performance test results of the half-cell assembled with commercial copper current collector and CuHHTP@Cu prepared in Example 1 and lithium foil. -2 The current density and 1 mAh cm -2 Under the capacity of 1.5 MW, CuHHTP@Cu can stably cycle for 500 cycles with better cycling performance, which proves that CuHHTP can effectively improve the kinetics of Li deposition-stripping.

[0083] Test Example 2

[0084] The CuHITP@Cu prepared in Example 2-7 was punched into a disc-shaped electrode sheet with a diameter of 13 mm as the positive electrode, and an ether electrolyte containing 1M electrolyte lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 5wt% electrolyte additive lithium nitrate (LiNO3) was prepared using 1,3-dioxolane (DOL) and ethylene glycol dimethyl ether (DME) in a volume ratio of 1:1 as solvent. The button cell Cu-HITP@CC-0.5-10 (Example 2-7) was assembled with lithium foil as the negative electrode. 2), Cu-HITP@CC-0.5-20 (Example 3), Cu-HITP@CC-0.5-30 (Example 4), Cu-HITP@CC-1-10 (Example 5), Cu-HITP@CC-1-20 (Example 6), Cu-HITP@CC-1-30 (Example 7), electrochemical test, the test method is: the button battery is left to rest for two hours, then the button battery is activated with a small current of 0.05mA, first discharged to 0V at a constant current, then charged to 1V, and the cycle is repeated 4 times. At 1mA·cm -2 The current density was 1mA·cm -2The battery was charged to 1 V at a current density of 100 nm and cycled.

[0085] The test results are as follows Figure 7 As shown, Figure 7 Figure 2 shows the long-cycle performance test results of the button cell assembled with CuHITP@Cu and lithium foil prepared in Example 2-7. Under the reaction conditions of a 0.5M HITP ligand solution, both Cu-HITP@CC-0.5-10 (330 cycles) and Cu-HITP@CC-0.5-20 (420 cycles) exhibited good cycling stability. In particular, Cu-HITP@CC-0.5-20 maintained a Coulombic efficiency of 97% after 420 cycles. However, after overreaction, the cycling stability of Cu-HITP@CC-0.5-30 was significantly reduced, lasting only 190 cycles. A large number of Cu-HITP nanosheets shed, reducing the cycling stability of the battery. A higher ligand concentration improves the reaction kinetics of HITP·6HCl with Cu(OH)2. Among them, Cu-HITP@CC-1-10 exhibits a cycling stability of 220 cycles, while the cycling performance of Cu-HITP@CC-1-20 (180 cycles) and Cu-HITP@CC-1-10 (150 cycles) is poor, which is due to similar reasons as the above-mentioned Cu-HITP@CC-0.5-30. The above results demonstrate the structure-activity relationship between structural integrity and electrochemical stability.

[0086] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a conductive Cu-based MOF by in-situ growth on a copper current collector, characterized in that: The following steps are involved: (1) mixing a sodium hydroxide solution and an ammonium persulfate solution to obtain a mixed solution; placing a copper current collector in the mixed solution to obtain a copper current collector having copper hydroxide nanowires grown on the surface; (2) dissolving 2,3,6,7,10,11-hexahydroxytriphenylenebenzene or 2,3,6,7,10,11-hexaaminotriphenylene hexahydrochloride in a solvent to obtain a ligand solution; placing the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) in the ligand solution, reacting at 60-70° C., washing and drying the copper current collector after the reaction, and then activating it at 100-200° C. to obtain a copper current collector with in-situ growth of a conductive Cu-based MOF.

2. The preparation method according to claim 1, characterized in that In step (1), the concentration of sodium hydroxide in the sodium hydroxide solution is 3-4 mol / L, the concentration of ammonium persulfate in the ammonium persulfate solution is 0.1-0.2 mol / L, and the volume ratio of the sodium hydroxide solution to the ammonium persulfate solution is 1:(0.8-1.2).

3. The preparation method according to claim 1, characterized in that In step (1), the copper current collector is placed in the mixed solution for 10-30 minutes.

4. The preparation method according to claim 1, characterized in that In step (2), the solvent is a mixed solvent of N,N-dimethylformamide and water or a mixed solvent of N,N-dimethylacetamide and water.

5. The preparation method according to claim 4, characterized in that In step (2), 2,3,6,7,10,11-hexahydroxytriphenylenebenzene is dissolved in a mixed solvent of DMF and water to obtain a ligand solution; the concentration of 2,3,6,7,10,11-hexahydroxytriphenylenebenzene in the ligand solution is 0.4-1 mg / mL.

6. The preparation method according to claim 4, characterized in that In step (2), 2,3,6,7,10,11-hexamidinitibenzenehexahydrochloride is dissolved in a mixed solvent of DMA and water to obtain a ligand solution; the concentration of 2,3,6,7,10,11-hexamidinitibenzenehexahydrochloride in the ligand solution is 0.4-1 mg / mL.

7. The preparation method according to claim 1, characterized in that In step (2), the copper current collector with copper hydroxide nanowires grown on the surface obtained in step (1) is placed in the ligand solution and reacted in an oil bath at 60-70°C for 10-20 minutes. The copper current collector after the reaction is cleaned and dried, and then placed in a tube furnace for activation treatment at 100-200°C for 1.5-2.5 hours to obtain a copper current collector with in-situ growth of a conductive Cu-based MOF.

8. A copper current collector with in-situ growth of a conductive Cu-based MOF prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the copper current collector with in-situ growth of a conductive Cu-based MOF according to claim 8 in a lithium metal battery.

10. The use according to claim 9, characterized in that The copper current collector with the in-situ grown conductive Cu-based MOF is made into an electrode sheet for assembling a lithium metal battery.

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