A network organic polymer and its preparation method, a battery cathode and an aqueous zinc-organic battery

Abstract

The application provides a reticular organic polymer, a preparation method, a battery positive electrode and a water-based zinc-organic battery, and belongs to the technical field of chemical power sources. The preparation method of the reticular organic polymer comprises the following steps: uniformly mixing 2,6-diaminoanthraquinone and 2,4,6-triformylphloroglucinol in N-methylpyrrolidone (mass ratio 1:(0.1-5.9):(10-100)) and reacting at a preset temperature, and then filtering, washing and vacuum drying to obtain the reticular organic polymer. The battery positive electrode and the water-based zinc-organic battery are prepared by using the above reticular organic polymer. In the process of the electrochemical reaction of the battery, the reticular organic polymer can promote the high-kinetic H + coordination redox reaction with ultra-low activation energy, thereby overcoming the slow interfacial charge transfer of Zn 2+ ions due to high desolvation energy barrier, and being beneficial to the comprehensive improvement of the battery performance.

Description

Technical Field

[0001] This invention belongs to the field of chemical power source technology, specifically relating to a network organic polymer and its preparation method, a battery positive electrode, and an aqueous zinc-organic battery. Background Technology

[0002] Aqueous zinc-organic batteries, due to their environmental friendliness, inherent safety, and the diversity of organic material structures, show great promise for large-scale energy storage. Metallic Zn 2+ Zinc ions are the most widely studied charge carriers in zinc-organic batteries, but their large ionic radius often leads to large solvation structures and high desolvation energy barriers, inevitably reducing ion diffusion kinetics and the structural stability of the organic cathode, ultimately resulting in a rapid decline in the battery device's capacity and cycle performance. In contrast, nonmetallic protons (H... + Charge carriers offer new possibilities for improving the electrochemical performance of batteries. + The ions possess the smallest ionic size and lightest weight, enabling rapid reaction kinetics to address Zn. 2+ The problem of slow charge transfer at the ion interface. Furthermore, H... + Ion coordination can significantly reduce the mass burden and structural expansion of organic cathodes, thus avoiding irreversible structural damage. Therefore, protons hold promise as ideal charge carriers for developing advanced zinc-organic batteries.

[0003] Despite the numerous advantages of proton storage, the design of matching cathode materials is still necessary to fully realize its potential. Organic materials with multiple proton-loving active sites and a robust framework are crucial for efficient proton storage. In recent years, various organic cathode materials with different active sites (such as imine, azo, and carbonyl) have been reported, among which carbonyl compounds stand out due to their high reactivity and H+. + The coordination sensitivity of carbonyl molecules has attracted much attention. However, the high solubility of small carbonyl molecules in aqueous electrolytes can lead to irreversible capacity loss during battery cycling. To overcome this obstacle, researchers often use the polymerization of soluble carbonyl monomers to construct stable organic cathodes. However, the twisted molecular chains and random cross-linking of polymers often result in disordered stacking structures, thereby reducing the utilization rate of redox-active carbonyl sites and limiting the battery's capacity storage. Therefore, there is an urgent need to develop organic polymers that possess abundant proton-loving carbonyl active sites, continuous and rapid electron delocalization pathways, and stable and ordered topologies to further improve the specific capacity and cycle life of proton storage. Summary of the Invention

[0004] This invention is made to solve the above-mentioned problems, and aims to provide a network organic polymer and its preparation method, a battery positive electrode, and an aqueous zinc-organic battery.

[0005] This invention provides a method for preparing a network organic polymer, characterized by the following steps: dissolving 2,6-diaminoanthraquinone and 2,4,6-tricarboxymethylresorcinol in N-methylpyrrolidone and mixing them evenly, reacting them at a preset temperature, and then filtering, washing, and vacuum drying to obtain the network organic polymer, wherein the mass ratio of 2,6-diaminoanthraquinone, 2,4,6-tricarboxymethylresorcinol, and N-methylpyrrolidone is 1:(0.1-5.9):(10-100).

[0006] The method for preparing the network organic polymer provided by the present invention may also have the following characteristics: wherein the preset temperature is 10℃~160℃, and the reaction is carried out at the preset temperature for 6h~24h.

[0007] The method for preparing the network organic polymer provided by the present invention may also have the following characteristics: ethanol or deionized water is used for washing, and vacuum drying is carried out at 80°C for 10-12 hours.

[0008] The present invention also provides a network organic polymer, characterized in that it is prepared by the above-described method for preparing network organic polymers.

[0009] The network organic polymer provided by this invention may also have the following characteristics: the network organic polymer has abundant protophilic carbonyl active sites, continuous and rapid electron delocalization pathways, and a stable network organic framework structure.

[0010] The present invention also provides a battery positive electrode, characterized by being prepared using the above-mentioned network organic polymer.

[0011] The battery positive electrode provided by the present invention may also have the following features: the preparation method of the battery positive electrode is as follows: weigh the network organic polymer, acetylene black conductive agent and polytetrafluoroethylene binder, add N-methylpyrrolidone and grind evenly to obtain a slurry, then coat the slurry evenly on the current collector, and dry to obtain the battery positive electrode.

[0012] The positive electrode of the battery provided by the present invention may also have the following feature: wherein the current collector is one of titanium foil, nickel mesh, titanium mesh, stainless steel mesh or carbon paper.

[0013] The positive electrode of the battery provided by the present invention may also have the following feature: wherein the mass ratio of the network organic polymer, the acetylene black conductive agent and the polytetrafluoroethylene binder is 6:3:1.

[0014] This invention also provides an aqueous zinc-organic battery, characterized by comprising: a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode is the positive electrode of the battery described above, the negative electrode is a high-purity commercial zinc foil with a zinc content ≥99.99%, and the electrolyte is one or more of Zn(CF3SO3)2, ZnSO4, and ZnCl2 aqueous solutions, with a concentration of 1 mol / L. -1 ~10mol / L -1 The diaphragm is made of filter paper or glass fiber.

[0015] The role and effect of invention

[0016] The preparation method of the network organic polymer involved in this invention selects 2,6-diaminoanthraquinone and 2,4,6-tricarboxymethyl phloroglucinol as building blocks, and the two are prepared in N-methylpyrrolidone solvent through hydrogen bonding and π-π stacking to obtain the network organic polymer.

[0017] The network organic polymer prepared in this invention is composed of nanofibers. Its continuous and rapid electron delocalization pathways fully expose the built-in protophilic carbonyl active sites, which is beneficial for a significant improvement in battery capacity and rate performance. The extended, interconnected network structure enhances the organic material's resistance to dissolution in the electrolyte, thus improving battery cycle life. Furthermore, during the battery electrochemical reaction, the network organic polymer of this invention can promote high-kinetic H+ reactions with ultra-low activation energy. + Coordination redox reaction, thereby overcoming Zn 2+ The slow interfacial charge transfer caused by the high desolvation energy barrier of ions is beneficial to the overall improvement of battery performance.

[0018] Therefore, the network organic polymer prepared by the method of the present invention possesses abundant protophilic carbonyl active sites, continuous and rapid electron delocalization pathways, and a stable network organic framework structure. Furthermore, when used as the positive electrode active material in an aqueous zinc-organic battery, it can interact with highly kinetic H+. + Preferential ion coordination results in an assembled battery with excellent capacity storage and rate performance, as well as outstanding cycle stability. This work is significant for eliciting superior proton activity in a variety of redox organic compounds to construct advanced zinc-organic batteries.

[0019] In addition, the main raw materials used in this invention are widely available, inexpensive and environmentally friendly. The entire electrode and electrolyte preparation process is carried out at room temperature and pressure, which is simple to operate and safe and pollution-free. Attached Figure Description

[0020] Figure 1 This is a scanning electron microscope image of the network organic polymer in Embodiment 1 of the present invention;

[0021] Figure 2 This is the structural formula of the network organic polymer in Embodiment 1 of the present invention;

[0022] Figure 3 It is the band gap of the network organic polymer in Embodiment 1 of the present invention;

[0023] Figure 4 This is the UV-Vis absorption spectrum of the network organic polymer in an aqueous electrolyte as measured in Example 1 of the present invention;

[0024] Figure 5 This is a scanning electron microscope image of the network organic polymer in Embodiment 2 of the present invention;

[0025] Figure 6 This is a rate performance diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 aqueous electrolyte in Example 3 of the present invention.

[0026] Figure 7 This is a cycle stability diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 aqueous electrolyte in Example 3 of the present invention at a current density of 20 A / g.

[0027] Figure 8 This is a rate performance diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 / acetonitrile electrolyte in the comparative example of the present invention.

[0028] Figure 9 This is a comparison diagram of the cycling stability of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 / acetonitrile electrolyte at a current density of 20 A / g. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the network organic polymer and its preparation method, the battery cathode and the aqueous zinc-organic battery of the present invention.

[0030] <Example 1>

[0031] Example 1 provides a network organic polymer and its preparation method.

[0032] The preparation method of the network organic polymer in this embodiment includes the following steps:

[0033] A network organic polymer was obtained by dissolving 2,6-diaminoanthraquinone, 2,4,6-tricarboxymethylresorcinol, and N-methylpyrrolidone in N-methylpyrrolidone at a mass ratio of 1:0.59:28.8. The mixture was homogeneous and reacted at 120°C for 12 h. After filtration and washing with deionized water, the polymer was dried under vacuum at 80°C for 12 h.

[0034] All raw materials used in this embodiment are commercially available reagent-grade products.

[0035] Figure 1 This is a scanning electron microscope image of the network organic polymer in Embodiment 1 of the present invention.

[0036] like Figure 1 As shown, the network organic polymer prepared in Example 1 is composed of basic nanofiber structural units.

[0037] Figure 2 This is the structural formula of the network organic polymer in Embodiment 1 of the present invention.

[0038] like Figure 2 As shown in Example 1, due to the electron-donating effect of the carbonyl group in the 2,4,6-tricarboxymethyl phloroglucinol molecule and the electron-withdrawing effect of the amine group in the 2,6-diaminoanthraquinone molecule, the two monomer molecules polymerize into nanofiber organic modules linked by -NH- bonds. Subsequently, driven by H bonds and π-π planar stacking, adjacent nanofiber networks further undergo longitudinal epitaxial growth and self-assemble into a regularly arranged network organic polymer.

[0039] Figure 3 It refers to the band gap of the network organic polymer in Embodiment 1 of the present invention.

[0040] like Figure 3 As shown, the network organic polymer prepared in this embodiment has an ultra-low band gap of 2.16 eV, which ensures high conductivity and efficient charge transfer, thereby driving redox reactions with lower kinetic resistance.

[0041] Figure 4 This is the UV-Vis absorption spectrum of the network organic polymer in an aqueous electrolyte as measured in Example 1 of the present invention.

[0042] like Figure 4 As shown, after UV-Vis absorption spectroscopy testing, no obvious absorption peak signal was observed in the electrolyte soaked in the network organic polymer, indicating that the structure of the network organic polymer is quite stable during the electrochemical reaction and is insoluble in the electrolyte. The anti-dissolution property of the network organic polymer in this embodiment mainly comes from its stable, interconnected network polymer structure.

[0043] <Example 2>

[0044] Example 2 provides a network organic polymer and its preparation method.

[0045] The preparation method of the network organic polymer in this embodiment includes the following steps:

[0046] A network organic polymer was obtained by dissolving 2,6-diaminoanthraquinone, 2,4,6-tricarboxymethylresorcinol, and N-methylpyrrolidone in N-methylpyrrolidone at a mass ratio of 1:1:28.8. The mixture was homogeneous and reacted at 100°C for 12 h. After filtration and washing with deionized water, the polymer was dried under vacuum at 80°C for 12 h.

[0047] All raw materials used in this embodiment are commercially available reagent-grade products.

[0048] Figure 5 This is a scanning electron microscope image of the network organic polymer in Embodiment 2 of the present invention.

[0049] like Figure 5 As shown, the network organic polymer prepared in this embodiment is composed of basic nanofiber structural units.

[0050] The structural formula of the network organic polymer in Example 2 is the same as that in Example 1.

[0051] <Example 3>

[0052] Example 3 provides a battery positive electrode and an aqueous zinc-organic battery, wherein the battery positive electrode uses the network organic polymer prepared in Example 1.

[0053] The preparation method of the battery positive electrode is as follows:

[0054] Weigh the network organic polymer, acetylene black conductive agent, and polytetrafluoroethylene binder prepared in Example 1 according to a mass ratio of 6:3:1. After adding N-methylpyrrolidone to a mortar, grind evenly for 30 minutes to obtain a slurry. Then, use a blade to evenly coat the slurry onto a titanium foil current collector with a diameter of 1.2 cm. After drying in an 80°C vacuum oven for 12 hours, the electrode sheet to be assembled is obtained as the positive electrode of the battery.

[0055] In this embodiment, the prepared battery positive electrode is further used to assemble an aqueous zinc-organic battery, as detailed below:

[0056] Using the prepared battery as the positive electrode and high-purity commercial zinc foil (zinc content ≥99.99%) as the negative electrode, a GE-Whatman glass fiber separator is placed between the positive and negative electrodes. After being arranged, the battery is placed in a CR2032 button cell battery case, and then 3M Zn(CF3SO3)2 electrolyte is added to assemble an aqueous zinc battery.

[0057] All raw materials used in this embodiment are commercially available reagent-grade products.

[0058] In this embodiment, the electrochemical performance of the prepared aqueous zinc-organic battery was also tested, including testing the energy storage performance of the device using a CHI660E electrochemical workstation. Cycle and rate performance tests were performed on a LAND CT2001A battery testing system. The voltage window was 0.35–1.75V.

[0059] Figure 6 This is a rate performance diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 aqueous electrolyte in Example 3 of the present invention.

[0060] like Figure 6 As shown, the zinc-organic battery prepared in this embodiment has a specific capacity of 350 mAh g when charged and discharged at 1 A / g. -1 Above, the rate capacity reaches 190mAh g when charged and discharged at 100A / g. -1 The above demonstrates high specific capacity storage performance.

[0061] Figure 7 This is a cycle stability diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 aqueous electrolyte in Example 3 of the present invention at a current density of 20 A / g.

[0062] like Figure 7 As shown, the zinc-organic battery assembled in this embodiment retains 83.3% of its capacity after 60,000 charge-discharge cycles, demonstrating excellent cycle stability.

[0063] <Comparative Example>

[0064] This comparative example provides a battery cathode and an aqueous zinc-organic battery, wherein the battery cathode uses the network organic polymer prepared in Example 1.

[0065] In this comparative example, the preparation method of the battery positive electrode is as follows:

[0066] Weigh the mesh organic polymer positive electrode, graphite conductive agent and polytetrafluoroethylene binder prepared in Example 1 according to a mass ratio of 6:3:1. After adding N-methylpyrrolidone to the mortar, grind evenly for 30 minutes to obtain a slurry. Then, use a blade to evenly coat the slurry onto a titanium foil current collector with a diameter of 1.2 cm. After drying in an 80°C vacuum oven for 12 hours, the electrode sheet to be assembled is obtained as the positive electrode of the battery.

[0067] In this comparative example, the prepared battery cathode was further used to assemble an aqueous zinc-organic battery, as detailed below:

[0068] Using the prepared battery as the positive electrode and high-purity commercial zinc foil (zinc content ≥99.99%) as the negative electrode, a GE-Whatman glass fiber separator is placed between the positive and negative electrodes. After arranging the battery, it is placed in a CR2032 button cell battery case, and then 0.5M Zn(CF3SO3)2 / acetonitrile electrolyte is added to assemble the zinc-organic battery.

[0069] In this comparative example, the electrochemical performance of the prepared zinc-organic battery was also tested, including testing the energy storage performance of the device using a CHI660E electrochemical workstation. Cycle and rate performance tests were performed on a LAND CT2001A battery testing system. The voltage window was 0.35–1.75V.

[0070] Figure 8 This is a rate performance diagram of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 / acetonitrile electrolyte, as shown in the comparative example of this invention.

[0071] like Figure 8 As shown, the zinc-organic battery prepared in this comparative example has a specific capacity of 83 mAh g when charged and discharged at 1 A / g. -1 The rate capability is 19 mAh g when charged and discharged at 100 A / g. -1 It exhibits poor specific capacity storage performance.

[0072] Figure 9 This is a comparison diagram of the cycling stability of a zinc-organic battery assembled with a mesh organic polymer positive electrode, a zinc foil negative electrode, and a Zn(CF3SO3)2 / acetonitrile electrolyte at a current density of 20 A / g.

[0073] like Figure 9 As shown, the zinc-organic battery assembled in this comparative example retains only 40.1% of its capacity after 10,000 charge-discharge cycles, indicating poor cycle stability.

[0074] A comparison of the performance test results of zinc-organic batteries prepared using different electrolytes in the comparative example and Example 3 shows that the cycle stability of the network organic polymer cathode in the Zn(CF3SO3)2 / H2O electrolyte (capacity retention of 83.3% after 60,000 cycles) is significantly better than that in the Zn(CF3SO3)2 / acetonitrile electrolyte (capacity retention of 40.1% after 10,000 cycles). Clearly, due to the solvated Zn... 2+ High ionic reaction energy barrier and sluggish interfacial charge transfer kinetics hinder the storage of Zn in the positive electrode of the network organic polymer.2+ It exhibits poor cycling stability when in the presence of ions.

[0075] The role and effect of the embodiments

[0076] As shown in Examples 1 and 2, the method for preparing a network organic polymer according to the present invention uses 2,6-diaminoanthraquinone and 2,4,6-tricarboxymethyl phloroglucinol as building blocks, which are then reacted in an N-methylpyrrolidone solvent via hydrogen bonding and π-π stacking to obtain a network organic polymer. This network organic polymer is composed of nanofibers, and its continuous and rapid electron delocalization pathways fully expose the built-in protophilic carbonyl active sites. The extended, interconnected network structure improves electron transport efficiency and enhances the organic material's resistance to dissolution in the electrolyte.

[0077] As shown in Example 3, when the network organic polymer prepared by this invention is used as the positive electrode active material of an aqueous zinc-organic battery, it can react with highly kinetic H+. + With preferential ion coordination, the assembled battery achieves a specific capacity of 350 mAh g at a charge / discharge rate of 1 A / g. -1 Above, the rate capacity reaches 190mAh g when charged and discharged at 100A / g. -1 The above demonstrates high specific capacity storage performance, and the capacity retention rate is over 80% after 60,000 charge-discharge cycles, exhibiting high specific capacity, energy density and superior cycle stability.

[0078] As can be seen from the comparative examples, during the battery electrochemical reaction process, the network organic polymer of the present invention can promote high-kinetic H2O with ultra-low activation energy. + Coordination redox reaction, thereby overcoming Zn 2+ The slow interfacial charge transfer caused by the high desolvation energy barrier of ions is beneficial to the overall improvement of battery performance.

[0079] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing a networked organic polymer, characterized by, The method comprises the following steps: 2,6-diaminoanthraquinone and 2,4,6-triformylphloroglucinol are dissolved in N-methylpyrrolidone, mixed uniformly, and reacted at a preset temperature, and then filtered, washed, and vacuum dried to obtain a reticular organic polymer, The mass ratio of 2,6-diaminoanthraquinone, 2,4,6-triformylphloroglucinol, and N-methylpyrrolidone is 1:(0.1-5.9):(10-100).

2. The method of claim 1, wherein the preset temperature is 10-160°C, and the reaction is performed at the preset temperature for 6-24 hours. wherein 3. The method of claim 1 or 2, wherein the washing is performed using ethanol or deionized water, and the vacuum drying is performed at 80°C for 10-12 hours. The reticular organic polymer is prepared by the method of any one of claims 1-3. wherein 5. The reticular organic polymer of claim 4, wherein the reticular organic polymer has abundant protonophilic carbonyl active sites, a continuous and rapid electron delocalization path, and a stable reticular organic skeleton structure. The reticular organic polymer is prepared by the method of claim 4 or 5.

4. A networked organic polymer, characterized by, 7. The battery positive electrode of claim 6, wherein the battery positive electrode is prepared by the following method: The reticular organic polymer, acetylene black conductive agent, and polytetrafluoroethylene binder are weighed, uniformly ground in N-methylpyrrolidone to obtain a slurry, and then the slurry is uniformly coated on a current collector to obtain the battery positive electrode after drying. wherein, 8. The battery positive electrode of claim 7, wherein the current collector is one of titanium foil, nickel mesh, titanium mesh, stainless steel mesh, or carbon paper.

6. A battery positive electrode, characterized by, 9. The battery positive electrode of claim 7 or 8, wherein the mass ratio of the reticular organic polymer, the acetylene black conductive agent, and the polytetrafluoroethylene binder is 6:3:

1. The battery comprises: wherein a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode is the battery positive electrode of any one of claims 6-9, the negative electrode is a high-purity commercial zinc foil with a zinc content of ≥99.99%, wherein the separator is filter paper or glass fiber. ​ wherein ​ 10. An aqueous zinc-organic battery, characterized in that ​ ​ ​ ​ The electrolyte is one or several of Zn(CF3SO3)2, ZnSO4, ZnCl2 aqueous solution, and the concentration of the electrolyte is 1 mol L -1 ~ 10 mol L -1 , ​

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