Fluorine-substituted graphdiyne-protected zinc negative electrode of zinc ion secondary battery as well as preparation method and application of zinc negative electrode

Abstract

The invention provides a fluorine-substituted graphdiyne-protected zinc negative electrode of a zinc ion secondary battery as well as a preparation method and application of the zinc negative electrode. The preparation method comprises the following steps: (1) preparing a reaction solution which comprises 1, 3, 5-trifluoro-2, 4, 6-trialkynyl benzene, cuprous iodide, pyridine, tetrahydrofuran and N, N, N ', N'-tetramethylethylenediamine; and (2) taking a zinc foil as a substrate, carrying out a cross-coupling reaction on 1, 3, 5-trifluoro-2, 4, 6-trialkynyl benzene in a reaction solution, and preparing the fluorine-substituted graphdiyne-protected zinc ion secondary battery zinc negative electrode on the surface of the zinc foil in situ. According to the preparation method provided by the invention, the fluorine-substituted graphdiyne is controllably grown on the surface of the zinc foil through an in-situ preparation method, and the preparation method is mild in condition, simple to operate and suitable for large-scale preparation. Moreover, the prepared fluorine-substituted graphdiyne-protected zinc negative electrode of the zinc ion secondary battery can be used as a new negative electrode material of the zinc ion secondary battery, the growth of zinc dendrites is inhibited, and the hydrogen evolution reaction is relieved, so that the cycle life of the zinc ion secondary battery is remarkably prolonged.

Description

Technical Field

[0001] The present invention belongs to the field of nanomaterials and preparation technology, and specifically relates to a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, a preparation method thereof and an application thereof. More specifically, the present invention relates to a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, a preparation method thereof and a zinc ion secondary battery using the same. Background Art

[0002] At present, the development of new secondary batteries has become an important means for mankind to deal with energy and environmental problems. Among the many new secondary battery systems, zinc-ion secondary batteries have attracted widespread attention due to their abundant reserves, low prices, high specific capacity, environmental friendliness, safety and stability, and have brought new opportunities and challenges to the development of new secondary batteries.

[0003] The negative electrode material of zinc ion secondary batteries generally uses zinc metal, which can be directly used in the negative electrode assembly of zinc ion secondary batteries due to its convenient processing, low cost, good conductivity, safety and environmental protection. In recent years, a series of studies on negative electrode materials for zinc ion secondary batteries have been reported (Zheng, J.;Zhao, Q.;Tang, T.;Yin, J.;Quilty, CD;Renderos, GD;Liu, X.;Deng, Y.;Wang, L.;Bock, DC;Jaye, C.;Zhang, D.;Takeuchi, ES;Takeuchi, KJ;Marschilok, AC;Archer, LA, Reversible epitaxial electrodeposition of metals in battery anodes. Science 2019, 366(6465), 645-648; Zhao, Z.;Zhao, J.;Hu, Z.;Li, J.;Li, J.;Zhang, Y.;Wang, C.;Cui, G., Long-life and deeply rechargeable aqueous Zn anodes enabled by amultifunctional brightener-inspired interphase. Energy Environ. Sci. 2019, 366(6465), 645-648). 12(6), 1938-1949; Zeng, Y.;Zhang, X.;Qin, R.;Liu, X.;Fang, P.;Zheng, D.;Tong,Y.;Lu, 31(36),1903675; Yu, M.;Chandrasekhar, N.;Raghupathy, RKM;Ly, KH;Zhang, H.;Dmitrieva, E.;Liang, C.;Lu, X.;Kühne, TD;Mirhosseini, H.;Weidinger, IM;Feng, X., A High-Rate Two-Dimensional Polyarylimide Covalent OrganicFramework Anode for Aqueous Zn-Ion Energy Storage Devices. J. Am. Chem. Soc.2020, 142(46), 19570-19578; Wang, C.;Wang, D.;Lv, D.;Peng, H.;Song, X.;Yang,J.;Qian, Y., Interface Engineering by Hydrophilic and Zincophilic AluminumHydroxide Fluoride for Anode-Free Zinc Metal Batteries at Low Temperature.Adv. Energy Mater. 2023, 13(20), 2204388; Luo, J.;Xu, L.;Zhou, Y.;Yan, T.;Shao, Y.;Yang, D.;Zhang, L.;Xia, Z.;Wang, T.;Zhang, L.;Cheng, T.;Shao, Y.,Regulating the Inner Helmholtz Plane with a High Donor Additive for EfficientAnode Reversibility in Aqueous Zn-Ion Batteries. Angew. Chem. Int. Ed. 2023,62(21), e202302302.), These studies provide a lot of experience for the development of negative electrodes for zinc-ion secondary batteries. .

[0004] However, zinc metal anodes still have problems such as zinc dendrites piercing the separator and causing battery short circuits during battery cycling, and hydrogen evolution side reactions causing electrolyte loss. These problems seriously affect the cycle life of zinc ion secondary batteries.

[0005] Therefore, the negative electrode materials of zinc ion secondary batteries still need to be improved at this stage. Summary of the invention

[0006] In view of the problems of dendrites and side reactions in the negative electrode materials of zinc ion batteries at this stage, the inventors found in the research process that fluorine-substituted graphyne forms a conjugated structure by connecting fluorine-substituted benzene rings with diyne bonds, and has zinc-philic fluorine atoms and uniformly distributed macropores. Based on this, the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne obtained by the in-situ preparation method of the present invention is used as the negative electrode material of the zinc ion battery, which can simultaneously inhibit the growth of zinc dendrites and the side reaction of hydrogen evolution, thereby significantly improving the cycle life of the zinc ion secondary battery.

[0007] In view of this, an object of the present invention is to provide a method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne in a simple and easy-to-mass production manner.

[0008] The method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne proposed in the present invention comprises the following steps: (1) preparing a reaction solution, wherein the reaction solution includes 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine; (2) Using zinc foil as a substrate, cuprous iodide as a catalyst, tetrahydrofuran as a solvent, N,N,N',N'-tetramethylethylenediamine as both a solvent and a base, and pyridine as a base, 1,3,5-trifluoro-2,4,6-triynylbenzene undergoes a cross-coupling reaction in the reaction solution to in-situ prepare the fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode on the zinc foil surface.

[0009] The inventors have found through research that fluorine-substituted graphyne can be controllably grown on the surface of zinc foil by an in-situ preparation method. The preparation method has mild conditions, simple operation and is suitable for large-scale preparation. In addition, the zinc negative electrode of the zinc ion secondary battery protected by the prepared fluorine-substituted graphyne can be used as a new negative electrode material for zinc ion secondary batteries, inhibiting the growth of zinc dendrites and slowing down the dehydrogenation reaction, thereby significantly improving the cycle life of zinc ion secondary batteries.

[0010] In step (1) of the above method, in the reaction solution, the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine can be 10:(1-2):(197-393):(8900-17800):(7750-15500) respectively.

[0011] In one embodiment of the present invention, in the reaction solution, the weight ratios of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine are 10:1:197:13350:11625 respectively; In one embodiment of the present invention, in the reaction solution, the weight ratios of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine are 10:1:197:8900:7750 respectively; In one embodiment of the present invention, in the reaction solution, the weight ratios of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine are 10:2:393:13350:11625 respectively.

[0012] In step (2), the reaction temperature of the in-situ preparation is 50±10 degrees Celsius; In one embodiment of the present invention, the reaction temperature of the in-situ preparation is 50 degrees Celsius; The reaction time of the in-situ preparation is 36 to 60 hours; In one embodiment of the present invention, the reaction time of the in-situ preparation is 48 hours; In one embodiment of the present invention, the reaction time of the in-situ preparation is 36 hours; In one embodiment of the present invention, the reaction time of the in-situ preparation is 60 hours.

[0013] Another object of the present invention is to provide a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0014] The fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode is prepared by the above method.

[0015] The inventors have found through research that the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in the present invention can be used as a new negative electrode material for the zinc ion secondary battery, inhibiting the growth of zinc dendrites and slowing down the hydrogen separation reaction, thereby significantly improving the cycle life of the zinc ion secondary battery.

[0016] Those skilled in the art will appreciate that the features and advantages described above for the method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne are still applicable to the zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, and will not be described in detail here.

[0017] The invention also provides a zinc ion secondary battery.

[0018] The zinc ion secondary battery comprises a negative electrode, and the negative electrode is the zinc negative electrode of the zinc ion secondary battery protected by the fluorine-substituted graphyne.

[0019] The inventors have found through research that the zinc ion secondary battery of the embodiment of the present invention, whose negative electrode is formed by a zinc ion secondary battery zinc negative electrode protected by fluorine-substituted graphyne, can inhibit the growth of zinc dendrites and slow down the hydrogen separation reaction, thereby significantly improving the cycle life of the zinc ion secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of a method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne according to an embodiment of the present invention; Figure 2 is a schematic diagram of a chemical reaction involved in an embodiment of the present invention; Figure 3 is a photograph of a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne prepared in an embodiment of the present invention; Figure 4 This is a SEM photo of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in an embodiment of the present invention; Figure 5 This is a Raman spectrum of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in an embodiment of the present invention; Figure 6 This is a photoelectron spectrum analysis diagram of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in an embodiment of the present invention; Figure 7 This is a comparison chart of battery cycle performance tests of the comparative example and the embodiment of the present invention; Figure 8 The SEM photos of the comparative example and the embodiment of the present invention after battery cycling are compared; Fig. 9 It is a comparison chart of linear sweep voltammetry test of comparative example and embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0022] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0023] In one aspect of the present invention, the present invention provides a method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne. Figure 1 , the preparation method of the present invention is described in detail.

[0024] According to an embodiment of the present invention, referring to Figure 1 , the preparation method comprises: S100: preparing a reaction solution.

[0025] In this step, a reaction solution is prepared, wherein the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is 10:(1~2):(197~393):(8900~17800):(7750~15500). In this way, the reaction solution formed by the above ratio can obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne by in-situ reaction. According to an embodiment of the present invention, the specific method for forming the reaction solution is not particularly limited. For example, cuprous iodide can be first dispersed in a mixed solution of tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine, and then 1,3,5-trifluoro-2,4,6-triynylbenzene and pyridine are added after ultrasonic dissolution. Those skilled in the art can make corresponding adjustments according to the degree of dispersion of the reaction solution.

[0026] In some embodiments of the present invention, the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is 10:(1~2):(197~393):(8900~17800):(7750~15500, so that a fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode can be successfully prepared. In addition, after long-term research, the inventors also found that if the content of cuprous iodide and pyridine is lower than the above ratio, or the content of tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is higher than the above ratio, the reaction degree of 1,3,5-trifluoro-2,4,6-triynylbenzene is low, and it is difficult to form a dense fluorine-substituted graphyne protective layer; if the content of cuprous iodide and pyridine is higher than the above ratio, or the content of tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is lower than the above ratio, 1,3,5-trifluoro-2,4,6-triynylbenzene will preferentially react in the solution, and it is also difficult to form a dense fluorine-substituted graphyne protective layer, and it will cause waste of reactants. In some specific examples, the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is 10:1:197:13350:11625, so that a higher quality fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode can be efficiently obtained.

[0027] S200: Using zinc foil as the substrate, a zinc negative electrode for zinc ion secondary battery protected by fluorine-substituted graphyne was prepared in situ in the reaction solution.

[0028] In this step, a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne is prepared in situ in the reaction solution prepared in step S100, using zinc foil as a substrate.

[0029] According to an embodiment of the present invention, the specific size of the zinc foil and the specific conditions for in-situ preparation are not particularly limited, and those skilled in the art can make corresponding adjustments based on the specific electrical performance results of the prepared fluorine-substituted graphyne-protected zinc negative electrode of the zinc ion secondary battery. In some embodiments of the present invention, the zinc foil may be a square with a thickness of 0.1 mm and a side length of 23 mm, and the in-situ preparation may be carried out at 50 ± 10 degrees Celsius. In this way, the conditions for in-situ preparation of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne at a temperature of 50 ± 10 degrees Celsius are milder and have lower energy consumption, and the fluorine-substituted graphyne protective layer of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared under this size is of better quality.

[0030] In some embodiments of the present invention, the time for in-situ preparation can be 36 to 60 hours, so that the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in situ within the above time range has better electrochemical performance. In addition, the inventors have found through long-term research that if the time for in-situ preparation is less than 36 hours, the degree of reaction of 1,3,5-trifluoro-2,4,6-triynylbenzene is low, and fluorine-substituted graphyne can only form a loose structure; if the time for in-situ preparation is greater than 60 hours, the fluorine-substituted graphyne layer obtained by the reaction is too thick, and the electrochemical performance of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne decreases. In some specific examples, the time for in-situ preparation can be 48 hours, so that a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne with excellent electrochemical performance can be prepared in situ more efficiently.

[0031] In summary, according to the embodiments of the present invention, the present invention proposes a preparation method, by which a fluorine-substituted graphyne protective layer can be in-situ grown on the surface of zinc foil through an in-situ preparation method, and the preparation method has mild conditions, simple operation and is suitable for large-scale preparation. In addition, the prepared fluorine-substituted graphyne-protected zinc negative electrode of the zinc ion secondary battery can be used as a new negative electrode material for the zinc ion secondary battery, inhibiting the growth of zinc dendrites and slowing down the dehydrogenation reaction, thereby significantly improving the cycle life of the zinc ion secondary battery.

[0032] In another aspect of the present invention, the present invention provides a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0033] According to an embodiment of the present invention, the fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode is prepared by the above method.

[0034] In summary, according to an embodiment of the present invention, the present invention proposes a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, which is used as a negative electrode material of a zinc ion secondary battery, and can inhibit the growth of zinc dendrites and slow down the dehydrogenation reaction, thereby significantly improving the cycle life of the zinc ion secondary battery. It can be understood by those skilled in the art that the features and advantages described above for the method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne are still applicable to the zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, and will not be repeated here.

[0035] In another aspect of the present invention, the present invention provides a zinc ion secondary battery.

[0036] According to an embodiment of the present invention, the zinc ion secondary battery includes a negative electrode, and the negative electrode is formed by the above-mentioned zinc ion secondary battery zinc negative electrode protected by fluorine-substituted graphyne.

[0037] In summary, according to an embodiment of the present invention, the present invention proposes a zinc ion secondary battery, whose negative electrode is formed by a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, which can inhibit zinc dendrite growth and slow hydrogen separation reaction, thereby significantly improving the cycle life of the zinc ion secondary battery. It can be understood by those skilled in the art that the features and advantages described above for the zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne are still applicable to the zinc ion secondary battery, and will not be repeated here.

[0038] The 1,3,5-trifluoro-2,4,6-triynylbenzene used in the following examples can be synthesized by referring to the following literature: Wang, Y.; Wei, S.; Qi, Z.-H.; Chen, S.; Zhu, K.; Ding, H.; Cao, Y.; Zhou, Q.; Wang, C.; Zhang, P.; Guo, X.; Yang, X.; Wu, X.; Song, L., Intercalant-induced V t 2g Orbital occupation in vanadium oxide cathode toward fast-charging aqueouszinc-ion batteries. PNAS 2023, 120(13), e2217208120.

[0039] The ammonium-doped vanadium pentoxide used in the following examples can be synthesized with reference to the following literature: Xing, C.; Xue, Y.; Huang, B.; Yu, H.; Hui, L.; Fang, Y.; Liu, Y.; Zhao, Y.; Li, Z.; Li, Y., Fluorographdiyne: A Metal-Free Catalyst for Applications in Water Reduction and Oxidation. Angew. Chem. Int. Ed. 2019, 58(39), 13897-13903.

[0040] Example 1 In this embodiment, a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne is prepared.

[0041] The specific method is to ultrasonically dissolve 1.0 mg of cuprous iodide in a mixed solvent of 15 mL of tetrahydrofuran and 15 mL of N,N,N',N'-tetramethylethylenediamine, and then add 0.25 mL of pyridine and 10 mg of 1,3,5-trifluoro-2,4,6-triynylbenzene, that is, the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine is 10:1:197:13350:11625. After mixing evenly, a square zinc foil with a thickness of 0.1 mm and a side length of 23 mm is placed in the reaction solution, and reacted at 50 degrees Celsius for 48 hours to obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0042] The chemical reaction diagram involved in this embodiment is as follows Figure 2 As shown; the obtained fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode photo is shown Figure 3 .

[0043] Then, the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne in the embodiment was analyzed by scanning electron microscopy (SEM), Raman spectroscopy and photoelectron spectroscopy. The SEM photo, Raman spectrum and spectral analysis diagram of the embodiment are shown in Figures 1 and 2. Figure 4~Figure 6 As shown, it is demonstrated that the preparation method successfully prepared the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne. Figure 4~Figure 6 Demonstrated the successful synthesis of fluorine-substituted graphyne materials.

[0044] Example 2 In this embodiment, according to the method and conditions substantially the same as those in Embodiment 1, 1.0 mg of cuprous iodide was ultrasonically dissolved in a mixed solvent of 10 mL of tetrahydrofuran and 10 mL of N,N,N',N'-tetramethylethylenediamine, and then 0.25 mL of pyridine and 10 mg of 1,3,5-trifluoro-2,4,6-triynylbenzene were added, i.e., the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine was 10:1:197:8900:7750. After uniform mixing, zinc foil was placed in the reaction solution and reacted at 50 degrees Celsius for 48 hours to obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0045] Example 3 In this embodiment, according to the method and conditions substantially the same as those in Embodiment 1, 2.0 mg of cuprous iodide was ultrasonically dissolved in a mixed solvent of 15 mL of tetrahydrofuran and 15 mL of N,N,N',N'-tetramethylethylenediamine, and then 0.50 mL of pyridine and 10 mg of 1,3,5-trifluoro-2,4,6-triynylbenzene were added, i.e., 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine in a weight ratio of 10:2:393:13350:11625. After uniform mixing, zinc foil was placed in the reaction solution and reacted at 50 degrees Celsius for 48 hours to obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0046] Example 4 In this embodiment, according to the method and conditions substantially the same as those in Embodiment 1, 1.0 mg of cuprous iodide was ultrasonically dissolved in a mixed solvent of 15 mL of tetrahydrofuran and 15 mL of N,N,N',N'-tetramethylethylenediamine, and then 0.25 mL of pyridine and 10 mg of 1,3,5-trifluoro-2,4,6-triynylbenzene were added, i.e., the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine was 10:1:197:13350:11625. After uniform mixing, zinc foil was placed in the reaction solution and reacted at 50 degrees Celsius for 36 hours to obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0047] Example 5 In this embodiment, according to the method and conditions substantially the same as those in Embodiment 1, 1.0 mg of cuprous iodide was ultrasonically dissolved in a mixed solvent of 15 mL of tetrahydrofuran and 15 mL of N,N,N',N'-tetramethylethylenediamine, and then 0.25 mL of pyridine and 10 mg of 1,3,5-trifluoro-2,4,6-triynylbenzene were added, i.e., the weight ratio of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine was 10:1:197:13350:11625. After uniform mixing, zinc foil was placed in the reaction solution and reacted at 50 degrees Celsius for 60 hours to obtain a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne.

[0048] Example 6 In this embodiment, the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in Example 1 was pressed into a circular negative electrode sheet with a diameter of 10 mm. A 2032-type button cell was assembled using ammonium-doped vanadium pentoxide as the positive electrode, qualitative filter paper as the diaphragm, and 3 M zinc trifluoromethanesulfonate aqueous solution as the electrolyte.

[0049] Comparative Example 1 In this comparative example, a 2032-type button cell was assembled using zinc foil as the negative electrode, ammonium-doped vanadium pentoxide as the positive electrode, qualitative filter paper as the separator, and a 3 M zinc trifluoromethanesulfonate aqueous solution as the electrolyte.

[0050] Example 7 In this embodiment, the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne prepared in Example 1 was cut into a square electrode sheet with a side length of 10 mm as the working electrode. A three-electrode system was assembled with a silver / silver chloride electrode as the reference electrode, a carbon rod as the counter electrode, and a 1 M zinc sulfate aqueous solution as the electrolyte.

[0051] Comparative Example 2 In this comparative example, a three-electrode system was assembled using zinc foil as a working electrode, a silver / silver chloride electrode as a reference electrode, a carbon rod as a counter electrode, and a 1 M zinc sulfate aqueous solution as an electrolyte.

[0052] Example 8 In this embodiment, the button cell of Example 6 and the button cell of Comparative Example 1, and the three-electrode system of Example 7 and the three-electrode system of Comparative Example 2 were tested for electrochemical performance. Specifically, at 1 A g -1 The button cell of Example 6 and the button cell of Comparative Example 1 were subjected to a cycle performance test at a current density of 10 mV s -1 The three-electrode system of Example 7 and the three-electrode system of Comparative Example 2 were subjected to linear sweep voltammetry test at a scan rate of . The test results show that: refer to Figure 7 The button cell of comparative example 1 is 1 A g -1 The maximum battery specific capacity is 205.2 mAh g -1 The cycle life is 475 times and the capacity retention rate is 43.1%. -1 The maximum battery specific capacity is 214.3 mA h g -1 The cycle life is 2000 times and the capacity retention rate is 67.3%. The cycle performance test shows that the cycle life of the button battery of Example 6 is significantly improved compared with the button battery of Comparative Example 1.

[0053] refer to Figure 8 The negative electrode of comparative example 1 grew a lot of zinc dendrites after battery cycling; the negative electrode of example 6 still had a smooth morphology after battery cycling. The SEM photos show that the negative electrode of example 6 can effectively inhibit the growth of zinc dendrites.

[0054] refer to Fig. 9 , at 10 mV s -1 At a scan rate of -50 mA cm -2 The corresponding potential is -1.356 V; the current density of Example 7 reaches -50 mA cm -2 The corresponding potential is -1.395 V. The linear sweep voltammetry test results show that the working electrode of Example 7 has a larger hydrogen evolution potential than the working electrode of Comparative Example 2, and the working electrode of Example 7 has a stronger ability to inhibit the hydrogen evolution reaction than the working electrode of Comparative Example 2.

[0055] Based on Examples 1 to 8 and Comparative Examples 1 to 2, it can be concluded that the preparation method proposed by the present invention can controllably grow fluorine-substituted graphyne on the surface of zinc foil through an in-situ preparation method. The preparation method has mild conditions, simple operation and is suitable for large-scale preparation. In addition, the prepared zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne can be used as a new negative electrode material for zinc ion secondary batteries, which can improve the cycle life of zinc ion secondary batteries, inhibit zinc dendrite growth, and slow down hydrogen separation reactions.

[0056] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wide range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principles of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departure from the disclosed scope in the application, and changes made with conventional techniques known in the art.

Claims

1. A method for preparing a zinc negative electrode of a zinc ion secondary battery protected by fluorine-substituted graphyne, comprising the following steps: (1) preparing a reaction solution, wherein: The reaction solution includes 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine; (2) Using zinc foil as a substrate, 1,3,5-trifluoro-2,4,6-triynylbenzene undergoes a cross-coupling reaction in the reaction solution, and the fluorine-substituted graphyne-protected zinc ion secondary battery zinc negative electrode is prepared in situ on the surface of the zinc foil.

2. The method according to claim 1, characterized in that In step (1), in the reaction solution, the weight ratios of 1,3,5-trifluoro-2,4,6-triynylbenzene, cuprous iodide, pyridine, tetrahydrofuran and N,N,N',N'-tetramethylethylenediamine are 10:(1-2):(197-393):(8900-17800):(7750-15500).

3. The method according to claim 1, characterized in that In step (2), the reaction temperature of the in-situ preparation is 50±10 degrees Celsius; the reaction time of the in-situ preparation is 36-60 hours.

4. A zinc negative electrode for a zinc ion secondary battery protected by fluorine-substituted graphyne prepared by the method according to any one of claims 1 to 3.

5. Use of the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne as claimed in claim 4 as the negative electrode of the zinc ion secondary battery.

6. A zinc ion secondary battery, wherein the negative electrode of the zinc ion secondary battery is the zinc negative electrode of the zinc ion secondary battery protected by fluorine-substituted graphyne as claimed in claim 4.

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