Preparation method of ion complex and supramolecular skeleton assembly, artificial solid electrolyte interface phase and zinc metal anode

Abstract

The application provides a preparation method of an ion complex and a supramolecular framework assembly, an artificial solid electrolyte interface phase and a zinc metal anode, and belongs to the field of supramolecular framework assemblies. The ion complex is prepared through ion interaction of a polyoxometalate cluster, coordination of zinc ions and cationic terpyridine and hydrogen bonding of grafted carboxyl groups, so that the three-dimensional SF is constructed in a good crystalline state. The three-dimensional growth of the framework of the ion complex is beneficial to improving the structural stability, while the unique performance is maintained. The ion complex can grow in situ on the zinc surface and further extend laterally to form a defect-free full coverage layer. Through dissolution and post-coordination effect, the 3D SF layer is used as an artificial solid electrolyte interface to improve the performance of the zinc anode. The clusters uniformly distributed in the nanopores of the ion complex form negatively charged nanochannels, which can accelerate the transfer of zinc ions and make the zinc deposition uniform.

Description

Technical Field

[0001] This invention relates to the field of supramolecular framework assembly technology, and particularly to a method for preparing an ionic complex and a supramolecular framework assembly, an artificial solid electrolyte interface phase, and a zinc metal anode. Background Technology

[0002] Framework structures with uniform nanopores have been found suitable for energy storage, particularly battery systems, because the ordered pores within the framework can provide ion transport channels without large volume changes. Aqueous zinc-ion batteries have generally attracted increasing attention due to their significant advantages such as high capacity, good safety, eco-friendliness, and low cost, showing great potential for large-scale energy storage and wearable devices. However, the poor reversibility of the zinc anode limits its practicality. Therefore, finding effective methods to improve reversibility in a simple way has become a key aspect. Artificial solid electrolyte interphase (ASEI) has proven particularly effective in regulating dendrite growth and preventing side reactions by isolating the electrolyte from Zn corrosion and inducing uniform Zn deposition. Porous materials have shown advantages in addressing related problems, and framework structures may be an excellent candidate. Many porous structures, such as metal-organic frameworks and covalent organic frameworks, have uniform and open channel structures with customizable properties, showing practical applicability as protective layers by coating their composites. However, the interaction between the coating and the substrate is often not constant during charge and discharge, making polymer doping inevitable. While some molecular frameworks can be grown directly in situ, their crystallinity often leads to uneven growth surfaces or harsh growth conditions, resulting in low protective capabilities. Therefore, achieving seamless and uniform porous layer coverage with additives under mild conditions remains highly desirable.

[0003] Compared to framework materials formed by covalent and coordination bonds, supramolecular frameworks (SFs) driven by intermolecular interactions exhibit greater structural flexibility and adaptability during interfacial growth. The utilization of various intermolecular forces enables SFs to grow in three dimensions, and the dynamic nature of these interactions not only provides structural tunability but also self-healing properties that can reduce defects. The search for SF assembly building blocks is less restrictive, thus expanding the range of functional groups available for improving battery performance. For example, polyoxometalates (POMs), as negatively charged clusters, can serve as basic building blocks for frameworks driven by electrostatic forces and covalent bonds. Due to their multiple charges, clusters with readily redox capabilities can organize into 3D SFs through strong ionic interactions with cationic ligands, thereby enhancing self-healing performance during electrochemical cycling. The added polyoxometalates also provide negatively charged diffusion channels. Simultaneously, the reduction of uniformly distributed polyoxometalates during electrochemical processes further enhances the negativeness of ion channels, accelerates zinc ion transfer, and homogenizes zinc deposition. However, existing 3D SF assemblies suffer from poor stability. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for preparing ionic complexes and supramolecular framework assemblies, an artificial solid electrolyte interface phase, and a zinc metal anode. This invention utilizes the prepared ionic complex to achieve in-situ growth of 3D SF on a zinc surface, enabling the construction of an artificial solid electrolyte interface in a well-crystallized state and improving stability.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing an ionic complex, comprising the following steps:

[0007] A bromination reaction was carried out by mixing p-hydroxybenzaldehyde, 1,2-dibromoethane and an organic solvent to obtain 4-(2-bromoethoxy)benzaldehyde;

[0008] The 4-(2-bromoethoxy)benzaldehyde, 2-acetylpyridine, ammonia, an inorganic alkaline substance, and an organic solvent were mixed and subjected to a condensation reaction to obtain 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine;

[0009] The 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine and pyridine were mixed and subjected to a quaternization reaction to obtain 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)bromopyridine;

[0010] An amide reaction was carried out by mixing an Anderson-type polyoxometalate, succinic anhydride, and an organic solvent to obtain an amide product. The Anderson-type polyoxometalate is [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6);

[0011] The amide product, a soluble inorganic metal salt, and an organic solvent are mixed to carry out a first ion substitution reaction to obtain the first ion substitution product.

[0012] The first ion-substitution product, 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide, and solvent were mixed to carry out a second ion-substitution reaction to obtain the ion complex.

[0013] Preferably, the molar equivalent ratio of the Anderson-type polyoxometalate to succinic anhydride is 1:20.

[0014] Preferably, the soluble inorganic metal salt is an alkali metal inorganic salt, and the molar ratio of the amide product to the alkali metal inorganic salt is 1:50.

[0015] Preferably, the molar ratio of the first ion-substituted product to 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide is 1:3.

[0016] The present invention also provides an ionic complex prepared by the preparation method described in the above technical solution.

[0017] The present invention also provides the application of the ion complex described in the above technical solution in zinc metal anodic protection.

[0018] This invention provides an artificial solid electrolyte interface phase, which is prepared by a method including the following steps: immersing a zinc sheet in a solution for in-situ growth to form a three-dimensional supramolecular framework assembly, wherein the solute in the solution is the ionic complex described in the above technical solution.

[0019] The present invention also provides a zinc metal anode, comprising a zinc anode substrate and an artificial solid electrolyte interface phase loaded on the surface of the zinc anode substrate, wherein the artificial solid electrolyte interface phase is the artificial solid electrolyte interface phase described in the above technical solution.

[0020] This invention also provides the application of the ionic complex described in the above technical solution in the preparation of supramolecular framework assemblies.

[0021] This invention provides a supramolecular framework assembly obtained by coordination of the ionic complex and zinc ions as described in the above technical solution.

[0022] This invention provides a method for preparing an ionic complex, comprising the following steps: a bromination reaction is carried out by mixing p-hydroxybenzaldehyde, 1,2-dibromoethane, and an organic solvent to obtain 4-(2-bromoethoxy)benzaldehyde; a condensation reaction is carried out by mixing the 4-(2-bromoethoxy)benzaldehyde, 2-acetylpyridine, ammonia, an inorganic basic substance, and an organic solvent to obtain 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine; the 4′-[4- [2-Bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine and pyridine are mixed and subjected to a quaternization reaction to give 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide; Anderson-type polyoxometalate, succinic anhydride and organic solvent are mixed and subjected to an amide reaction to give an amide product, wherein the Anderson-type polyoxometalate is [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6); The amide product, a soluble inorganic metal salt, and an organic solvent are mixed to carry out a first ion substitution reaction to obtain a first ion substitution product; The first ion substitution product, 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide, and a solvent are mixed to carry out a second ion substitution reaction to obtain the ion complex.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] Based on the principle that dynamic reversible non-covalent interactions enable supramolecular framework structures to possess flexibility and designability, this invention prepares the aforementioned ionic complex. Through the ionic interactions of polyoxometalate clusters, coordination between zinc ions and cation terpyridine, and hydrogen bonding of grafted carboxyl groups, the construction of three-dimensional SF in a well-crystallized state is achieved. The three-dimensional growth of the framework of the ionic complex is beneficial to improving structural stability while maintaining its unique properties. The ionic complex of this invention can grow in situ on the zinc surface and further extend laterally to form a defect-free full-coverage layer. Utilizing the dissolution and post-coordination effects, and using the 3D SF layer as an artificial solid electrolyte interface, the performance of the zinc anode is improved. The uniformly distributed clusters within the nanopores of the ionic complex form negatively charged nanochannels, which can accelerate zinc ion transfer and homogenize zinc deposition.

[0025] This invention also provides a supramolecular framework assembly obtained by coordination of the ionic complex and zinc ions as described in the above-mentioned technical solution. Through appropriate structural design and selection of building blocks, this invention precisely constructs 3D SF and can fully utilize the excellent electronegativity and redox properties of POM clusters through anion channels. Simultaneously, the porous SF structure can be in-situ assembled on the zinc anode surface as a protective layer through coordination with zinc ions. The resulting 3D SF is formed by hydrogen bonding, creating a stable crystalline structure layer adhered to the surface, ensuring the reliability of battery operation; ultra-large ordered pores penetrate the three-dimensional framework film to reach the anode surface, promoting Zn... 2+ Rapid and uniform migration of zinc ions induces dominant growth of the Zn(002) crystal plane, resulting in dendrite-free Zn deposition. Precisely designed POM clusters on the pore walls of 3D SF provide a negatively charged nanochannel, accelerating the transfer of zinc ions at the interface and shielding against SO42-. 2- Near the anode. Data from the examples show that the 3D SF / Zn anode performs well at 5 mA·cm⁻¹. -2 It exhibits excellent stability at current densities, sustaining over 4800 cycles with an average coulombic efficiency of 99.86%, and a cycle life of up to 3000 hours. This invention provides structural flexibility to avoid potential gaps and cracks, while the multiple intermolecular interactions are stable under operating conditions due to the dynamic nature of their reformation within the cross-linked framework structure. Therefore, this invention demonstrates a simple and effective strategy to combine the advantages of supramolecular frameworks based on polyanionic clusters for zinc anode protection layers, providing theoretical support for expansion into other advanced energy storage systems. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of PCMM fabrication using TAMM.

[0027] Figure 2 A schematic diagram for the fabrication of 2D SF;

[0028] Figure 3 The diagrams show the coordination interaction characteristics, where a is the XPS spectrum of the 2D SF assembly of PCMM and PCMM-ZnSO4, and b is the FT-IR spectrum of the 2D SF assembly of PCMM and PCMM-ZnSO4.

[0029] Figure 4 In [Zn], 'a' represents the value of 'a' in [Zn]. 2+ [PCMM] When the molar ratios are 0:1, 0.1:1, 0.2:1, 0.3:1, 0.6:1, 0.9:1, 1.2:1, 1.5:1, 1.8:1, 2.1:1, 2.4:1, and 2.7:1, the Zn content in DMF / H2O (volume ratio 1:1) 2+The UV-Vis titration spectra of PCMM, where b is the value of [Zn] 2+ [PCMM] The absorption Job plot at 340 nm corresponding to the increase in molar ratio;

[0030] Figure 5 The images are 2D SF characterization diagrams, where a and b are TEM images at different magnifications, c is an AFM image, and d is an XRD pattern.

[0031] Figure 6 The images are characterization diagrams of 3D SF, where a to c are TEM images and local magnification diagrams, d is an atomic force microscope image, e is a polarizing microscope image, f is an XRD pattern, g is a nitrogen adsorption isotherm at 77 K and a calculated pore size distribution diagram, h is the structure diagram of the corresponding crystal plane in the ab direction, and i is the structure diagram of the corresponding crystal plane in the ac direction.

[0032] Figure 7 The image shows the SAED pattern of 3D SF, where a to d are diffraction patterns of different crystal planes;

[0033] Figure 8 The graphs show the characterization of hydrogen bonds, where a and b are the FT-IR spectra of PCMM, 2D SF, and 3D SF at different wavenumbers, respectively.

[0034] Figure 9 A schematic diagram of hydrogen bond formation;

[0035] Figure 10 To illustrate the in-situ growth of 3D SF on a Zn anode, images a–c show the SEM morphology of 3D SF grown on a Zn plate for 1, 2, and 3 hours, images d and e show SEM cross-sectional images at different magnifications, image f shows the XPS image of 3D SF / Zn, image g shows the SEM image of 3D SF / Zn, image h shows the elemental distribution map of Mn, image i shows the elemental distribution map of Mo, and image j shows the elemental distribution map of C.

[0036] Figure 11 The powder XRD pattern of 3D SF grown in situ on a Zn anode prepared by DMF / H2O (volume ratio 1:1) at pH=3 is shown in the inset. The inset is an enlarged XRD pattern of the diffraction peaks of 3D SF.

[0037] Figure 12 The morphological evolution of bare zinc and 3D SF / Zn electrodes after repeated plating / stripping is shown, where a and b are bare Zn and 3D SF / Zn at 20 mA·cm⁻¹, respectively. -2 Optical microscope images taken under the deposition conditions from 0 to 60 min, with a scale bar of 50 μm and c and d at 10 mA·cm. -2 1mAh·cm -2SEM images of 3D SF / Zn and bare Zn anodes after the next cycle, e and f are X-ray diffraction results of Zn anodes after different cycles, and g is a schematic diagram of the reaction process and corresponding morphological evolution on the zinc anode with and without 3D SF.

[0038] Figure 13 In the range of a to c at 10 mA·cm -2 1mAh·cm -2 Scanning electron microscopy (SEM) images of the 3D SF semi-coated zinc anode in the symmetric cell after cycling reveal the zinc deposition morphology.

[0039] Figure 14 The images show the zinc deposition morphology at different cycles using scanning electron microscopy (SEM). Images a through f are SEM images of bare Zn at different magnifications in the 10th, 30th, and 100th cycles, respectively, while images g through l are SEM images of 3D SF / Zn at different magnifications in the 10th, 30th, and 100th cycles, respectively.

[0040] Figure 15 The results are X-ray diffraction results, where a and b are bare Zn and 3D SF / Zn anodes after different cycles, c is the intensity ratio of Zn(002) to Zn(100), and d is the intensity ratio of Zn(002) to Zn(101).

[0041] Figure 16 For the zinc affinity properties of 3D SF and enhanced Zn 2+ Migration performance characterization: a and b represent the water contact angles and corresponding wetting free energies of 3D SF / Zn and bare Zn, respectively; c represents the Zeta potential distribution of 3D SF in water; d represents the 3D SF / Zn electrode at 10 mA·cm⁻¹. -2 1mAh·cm -2 XPS after 100 cycles, e represents CAs of bare zinc and 3D SF / Zn cells at an overpotential of -150mV, and F represents the Zn content of bare zinc and 3D SF / Zn cells. 2+ For the migration number comparison, g is the calculated Zn 2+ Energy distribution along the migration path of the 3D SF anion channel, where h represents the calculation model of 3DSF adsorption of Zn (gray spheres represent adsorbed Zn) and the 3D SF charge density difference of adsorbed Zn.

[0042] Figure 17 The contact angles of 3D SF / Zn at different in-situ growth times are shown in Figure 1. a represents bare zinc, b to d represent 3D SF / Zn at 1, 2 and 3 h respectively, and 2M ZnSO4 aqueous solution is used as the electrolyte. e represents the absolute wetting free energy.

[0043] Figure 18 XRD patterns of bare zinc and 3D SF / Zn anodes after 100 cycles;

[0044] Figure 19 CVs for stripping zinc plating from bare Zn||Ti foil and 3D SF / Zn||Ti foil;

[0045] Figure 20 The current-time plot of the symmetrical zinc battery is shown, where a and b are the impedance spectra of bare zinc and 3D SF / Zn electrodes after polarization at a constant potential of 10mV for 20 min, and the inset shows the impedance spectra before and after polarization.

[0046] Figure 21 Zn for 3D SF / Zn components 2+ Migration performance graphs, where a is the LSV curve of 3D SF / Zn and bare Zn, and b is the ionic conductivity test graph of 3D SF / Zn and bare Zn;

[0047] Figure 22 The image shows the DFT plot of the adsorption energy of bare zinc.

[0048] Figure 23 The graph shows the electrochemical performance of 3D SF / Zn and bare Zn electrodes, where a represents the symmetric cell at 5 mA·cm⁻¹. -2 1mAh·cm -2 Long-cycle performance at 10 mA·cm -2 1mAh·cm -2 Under the given conditions, the coulombic efficiency of zinc-plated / stripped zinc in bare Zn||Cu and 3D SF / Zn||Cu asymmetric cells, c is the efficiency at 1 A·g -1 The long-term performance is shown in Figure d, which is the EIS curve of the full cell of 3D SF / Zn and bare Zn. The SEM images of bare Zn and 3D SF / Zn after the full cell test of Zn||MnO2 and 3D SF / Zn||MnO2 are shown in Figure d, respectively.

[0049] Figure 24 Symmetric cells of 3D SF / Zn and bare Zn at 10 mA·cm -2 and 1mAh·cm -2 The following is a graph showing the long-cycle performance of a symmetrical battery.

[0050] Figure 25 For 5mA·cm -2 1mAh·cm -2 Coulombic efficiency plots of zinc plating / stripping in bare Zn||Cu and 3D SF / Zn||Cu asymmetric cells;

[0051] Figure 26 The voltage distribution diagram shows that a and b are bare Zn||Cu and 3D SF / Zn||Cu cells, respectively, with a voltage of 10 mA·cm⁻¹. -2 and 1mAh·cm-2 ;

[0052] Figure 27 For 3D SF / Zn symmetric cells at different current densities from 5 to 50 mA·cm -2 Performance chart at various rates;

[0053] Figure 28 The performance of zinc metal anodes is compared, where a and b are the performance comparisons of organic, inorganic, and organic / inorganic hybrid SEI protective layers in asymmetric and symmetric cells, respectively.

[0054] Figure 29 The results are for the full cell, where a is 0.1 mV·s. -1 The CV curve at time b is 0.2–3 A·g. -1 Rate performance;

[0055] Figure 30 This document describes the preparation of SF assemblies and their negatively charged ion channels. Figure a shows the structural diagrams of the prepared carboxyl-grafted cluster SCMM, the cationic ligand Py-TPY, and its ion complex PCMM. Figure b shows the process of passing Zn through DMF / H2O (volume ratio 1:1) at pH 3 (or 7). 2+ A schematic diagram of in-situ growth of 3D SF on a Zn anode in DMF / H2O (volume ratio 1:1) at pH 3 for coordination preparation of 3D (or 2D) SF, and an ordered POM cluster providing zinc ion transfer channels. Detailed Implementation

[0056] This invention provides a method for preparing an ionic complex, comprising the following steps:

[0057] A bromination reaction was carried out by mixing p-hydroxybenzaldehyde (PHBA), 1,2-dibromoethane and an organic solvent to obtain 4-(2-bromoethoxy)benzaldehyde (Br-PHBA);

[0058] The 4-(2-bromoethoxy)benzaldehyde, 2-acetylpyridine, ammonia, an inorganic alkaline substance, and an organic solvent were mixed and subjected to a condensation reaction to obtain 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine (Br-TPY);

[0059] The 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine and pyridine were mixed and subjected to a quaternization reaction to obtain 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide (Py-TPY·Br);

[0060] An amide reaction was carried out by mixing an Anderson-type polyoxometalate, succinic anhydride, and an organic solvent to obtain the amide product (TCMM). The Anderson-type polyoxometalate is [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6)(TAMM);

[0061] The amide product, a soluble inorganic metal salt, and an organic solvent are mixed and subjected to a first ion substitution reaction to obtain the first ion substitution product (SCMM).

[0062] The first ion-substitution product, 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide, and solvent were mixed to carry out a second ion-substitution reaction to obtain the ion complex (PCMM).

[0063] In this invention, unless otherwise specified, all raw materials used are commercially available products or can be prepared using methods well known to those skilled in the art.

[0064] In this invention, the principle for preparing 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide (Py-TPY·Br) is shown in the following formula:

[0065]

[0066] In this invention, p-hydroxybenzaldehyde, 1,2-dibromoethane and an organic solvent are mixed and subjected to a bromination reaction to obtain 4-(2-bromoethoxy)benzaldehyde.

[0067] In this invention, the molar ratio of p-hydroxybenzaldehyde to 1,2-dibromoethane is preferably 1:2.

[0068] In this invention, the bromination reaction is preferably carried out under reflux conditions for a time of 4 to 8 hours.

[0069] In this invention, the organic solvent is preferably acetone.

[0070] In this invention, the mixture of p-hydroxybenzaldehyde and 1,2-dibromoethane is refluxed in dry acetone for 5 hours to carry out the bromination reaction. The resulting reaction mixture is then poured into water, extracted with dichloromethane, dried on sodium sulfate, and the solvent is removed under reduced pressure. The residue is then purified on silica gel using a mixed eluent of chloroform and petroleum ether (volume ratio 1:4) to obtain the 4-(2-bromoethoxy)benzaldehyde.

[0071] After obtaining 4-(2-bromoethoxy)benzaldehyde, the present invention mixes the 4-(2-bromoethoxy)benzaldehyde, 2-acetylpyridine, ammonia, an inorganic alkaline substance and an organic solvent to carry out a condensation reaction to obtain 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine.

[0072] In this invention, the molar ratio of 2-acetylpyridine to 4-(2-bromoethoxy)benzaldehyde is preferably 2:1.

[0073] In this invention, the condensation reaction is preferably carried out at a temperature of 50°C and for a time of 24 hours.

[0074] In this invention, the organic solvent is preferably methanol; the inorganic alkaline substance is preferably KOH.

[0075] In this invention, 2-acetylpyridine is added to a methanol solution of 4-(2-bromoethoxy)benzaldehyde, and ammonia and KOH solid are added to the resulting solution simultaneously to carry out the condensation reaction.

[0076] After the condensation reaction is completed, the present invention preferably filters the solid, then washes it with H2O and CH3OH, adds CHCl3, evaporates the solvent, and performs column chromatography on silica gel with a mixed eluent of CH2Cl2 / MeOH / Et3N (volume ratio 100 / 1 / 0.1) to obtain the 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine.

[0077] After obtaining 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine, the present invention mixes the 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine with pyridine and carries out a quaternization reaction to obtain 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)bromopyridine.

[0078] In this invention, the preferred ratio of 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine to pyridine is 2.3 mmol: 50 mL.

[0079] In this invention, the quaternization reaction is preferably carried out at a temperature of 90°C and for a time of 48 hours.

[0080] In this invention, the quaternization reaction is preferably carried out by dissolving the 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine in a pyridine solution.

[0081] After the quaternization reaction, the present invention preferably cools the obtained product to room temperature naturally and then adds diethyl ether to obtain a gray solid. The gray solid is then subjected to pressure filtration, washing with diethyl ether and drying to obtain 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)bromopyridine.

[0082] In this invention, the principle of preparing the PCMM from the TAMM is as follows: Figure 1 As shown.

[0083] This invention involves mixing an Anderson-type polyoxometalate, succinic anhydride, and an organic solvent to perform an amide reaction, yielding an amide product (TCMM). The Anderson-type polyoxometalate is [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6)(TAMM).

[0084] In this invention, the preferred molar equivalent ratio of the Anderson-type polyoxometalate to succinic anhydride is 1:20.

[0085] In this invention, the organic solvent is preferably CH3CN.

[0086] In this invention, the amide reaction is preferably carried out under reflux conditions for a period of 24 hours.

[0087] After the amide reaction is completed, the present invention preferably uses the amide reaction product obtained by diffusion with diethyl ether.

[0088] After obtaining the amide product, the present invention mixes the amide product, a soluble inorganic metal salt and an organic solvent to carry out a first ion substitution reaction to obtain a first ion substitution product.

[0089] In this invention, the soluble inorganic metal salt is an alkali metal inorganic salt, and the molar ratio of the amide product to the alkali metal inorganic salt is preferably 1:50.

[0090] In this invention, the alkali metal inorganic salt is preferably NaClO4.

[0091] In this invention, the organic solvent is preferably CH3CN.

[0092] In this invention, the temperature of the first ion substitution reaction is preferably room temperature, and the time is preferably 24 hours.

[0093] After the first ion substitution reaction is completed, the present invention preferably filters the obtained product to obtain a solid, and washes the solid with acetonitrile to obtain the first ion substitution product.

[0094] After obtaining the first ion-substitution product, the present invention mixes the first ion-substitution product, 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide and solvent to carry out a second ion-substitution reaction to obtain the ion complex.

[0095] In this invention, the solvent is preferably a CH3OH-H2O mixture, and the volume ratio of CH3OH to H2O in the CH3OH-H2O mixture is preferably 1:1.

[0096] In this invention, the molar ratio of the first ion-substituted product to 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide is preferably 1:3.

[0097] In this invention, the temperature of the second ion substitution reaction is preferably room temperature, and the time is preferably 24 hours.

[0098] After the second ion substitution reaction is completed, the present invention preferably washes the obtained product twice with CH3OH to obtain the ion complex.

[0099] The present invention also provides an ionic complex prepared by the preparation method described in the above technical solution.

[0100] The present invention also provides the application of the ion complex described in the above technical solution in zinc metal anodic protection.

[0101] This invention provides an artificial solid electrolyte interface phase, which is prepared by a method including the following steps: immersing a zinc sheet in a solution for in-situ growth to form a three-dimensional supramolecular framework assembly, wherein the solute in the solution is the ionic complex described in the above technical solution.

[0102] The present invention also provides a zinc metal anode, comprising a zinc anode substrate and an artificial solid electrolyte interface phase loaded on the surface of the zinc anode substrate, wherein the artificial solid electrolyte interface phase is the artificial solid electrolyte interface phase described in the above technical solution.

[0103] This invention also provides the application of the ionic complex described above in the preparation of supramolecular framework assemblies.

[0104] This invention provides a supramolecular framework assembly obtained by coordination of the ionic complex and zinc ions as described in the above technical solution.

[0105] In this invention, the supramolecular framework assembly includes 2D SF and 3D SF.

[0106] The present invention also provides a method for preparing the 2D SF described in the above technical solution, comprising the following steps:

[0107] The ionic complex, soluble zinc salt, and solvent are mixed to obtain the 2D SF.

[0108] In this invention, the molar ratio of the ionic complex to the soluble zinc salt is preferably 2:3.

[0109] In this invention, the soluble zinc salt is preferably ZnSO4.

[0110] In this invention, the solvent is preferably a DMF-H2O mixture, and the volume ratio of DMF to H2O in the DMF-H2O mixture is preferably 1:1. Preferably, the 2D SF is prepared at a pH of 7.

[0111] Preferably, the ionic complex and the soluble zinc salt are dissolved in a solvent separately and then mixed.

[0112] The present invention also provides a method for preparing the 3D SF described in the above technical solution, comprising the following steps:

[0113] The ionic complex, soluble zinc salt, and solvent are mixed and the pH is adjusted to 3-4 to obtain the 3D SF.

[0114] The present invention preferably adjusts the pH value by adding sulfuric acid, wherein the concentration of the sulfuric acid is preferably 1M.

[0115] In this invention, the other parameters in the process of preparing 3D SF are the same as those in the process of preparing 2D SF, and will not be repeated here.

[0116] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0117] The testing method in this embodiment of the invention includes:

[0118] Using tetramethylsilane (TMS) as an internal reference (s = singlet, br = broad-weighted state, d = doublet, t = triplet, q = quartet, m = multiplyt), data were recorded on a Bruker Avance 500MHz spectrometer. 1 H NMR and 13 C10 NMR spectra. FT-IR spectra (KBr particles) were acquired (32 scans) on a Bruker apex 80V spectrometer equipped with a DTGS detector, with a resolution of 4 cm⁻¹. -1Organic elemental analysis (C, H, N) was performed on the Vario microcubes from Elementar. Transmission electron microscopy (TEM) images were obtained on a field emission electron microscope (JEOL JEM-2100F) with an accelerating voltage of 200 kV and without staining. Scanning electron microscopy (SEM) measurements were performed on a JEOL JSM-6700F field emission scanning electron microscope. Atomic force microscopy (AFM) images were taken under ambient conditions using a Bruker Dimension FastScan™ atomic force microscope. The wavelength was [not specified in the original text]. The Cu Kα1 radiation was recorded by X-ray diffraction (XRD) on a Rigaku SmartLab 3 X-ray diffractometer. Static water contact angle (CA) measurements were analyzed using a DSA10-MK2 system. X-ray photoelectron spectroscopy analysis was performed using a monochromatic X-ray source (Al-Ka line, 1486.6 eV) on a Thermo ESCALAB 250 spectrometer, and the charge displacement was corrected using the binding energy of C(1s) at 285.0 eV.

[0119] Electrochemical testing methods

[0120] Symmetric zinc-ion batteries consist of two identical three-dimensional SF / Zn electrodes or two bare Zn electrodes with a diameter of 10 mm. Asymmetric batteries use two different electrode assemblies, one of which is bare Cu, and the other is either 3D SF / Zn or bare Zn. Glass fiber is used as the separator, and 2M ZnSO4 aqueous solution is used as the electrolyte for both symmetric and asymmetric batteries. The full-cell cathode electrode was prepared by mixing CNT-MnO2 powder, Super P, and polyvinylidene fluoride (PVDF) in N-methylpyridine at a mass ratio of 7:2:1. The mixture was ground for 20 minutes to ensure uniform dispersion of the active material. The slurry mixture was then coated onto Ti foil with a doctor's blade and dried in a vacuum oven at 60 °C for 24 h. The mass loading of the CNT-MnO2 cathode was 1 mg·cm⁻¹. 2 The electrolyte is a 2M ZnSO4 / 0.2M MnSO4 aqueous solution.

[0121] All batteries were assembled in CR2032-tpye coin cells at room temperature. Constant current charge-discharge and cycle performance tests were performed on a LANHE CT3002AU automated battery tester. Electrochemical impedance spectroscopy (EIS) measurements were conducted at 10... -1 ~10 6 The tests were conducted within a constant frequency range of Hz. Cyclic voltammetry (CV), corrosion, and hydrogen evolution curves were recorded using a VSP electrochemical workstation (Biologic SAS, France). The scan rate was 0.1 mV·s within the voltage range of 0.8–1.8 V. -1The CV curves of the battery at full charge were obtained. Chronoamperometry (CA) measurements of three-dimensional SF / Zn or bare Zn symmetric cells assembled at a fixed overpotential of -150 mV were studied on an electrochemical workstation. LSV curves validating the electrochemical window were recorded using three-dimensional SF / Ti and bare Ti asymmetric cells. Corrosion tests were conducted in a three-electrode system using three-dimensional SF / Zn (or bare Zn) as the working and counter electrodes, and Ag / AgCl as the reference electrode.

[0122] Linear sweep voltammetry (LSV) was performed on the same instrument for zinc symmetric cells. The aqueous electrolyte was a 2M ZnSO4 aqueous solution, and the cell was charged at 1 mA·cm⁻¹. -2 The current discharge deposits a certain amount of zinc on the working electrode, and then strips it off until the charging voltage reaches 0.5V (Zn). 2+ / Zn). The ionic conductivity of the zinc foil||electrolyte||diaphragm||electrolyte|| structure was tested at room temperature. The ionic conductivity was calculated using the formula σ=L / Rs·S, where L is the separator thickness, Rs is the volume resistivity, and S is the zinc foil area.

[0123] DFT calculation method

[0124] DFT simulations were performed using the available CP2K / Quickstep package. Periodic supercells were applied. The size of the cluster system was [size missing]. The size of Zn(002) is set to The 2s and 2p electrons of C, O, and N, and the 3d and 4s electrons of Zn, are used as valence electrons, and the remaining core electrons are represented by the Goedecker-Teter-Hutter (GTH) pseudopotential. The Gausky set is double-ζ with a set of polarization functions (dzpv-molopt-sr-gth), and the plane wave cutoff is set to 400Ry. The Perdew-Burke-Ernzerhof (PBE) density functional with Grime D3 dispersion correction is used. The geometry is optimized using the BFGS minimization algorithm. The Climb Image Push Elasticity (CI-NEB) method implemented in CP2K is used to calculate Zn. 2+ A diffusion barrier.

[0125] Example 1

[0126] Preparation of 4-(2-bromoethoxy)benzaldehyde (Br-PHBA). A mixture of p-hydroxybenzaldehyde (1.2 g, 10 mmol) and 1,2-dibromoethane (3.7 g, 20 mmol) was refluxed in dry acetone (20 mL) for 5 h to induce bromination. The reaction mixture was then poured into water and extracted with dichloromethane. After drying on sodium sulfate, the solvent was removed under reduced pressure, and the residue was purified on silica gel using a mixed eluent of chloroform and petroleum ether (1:4 v / v) to give 2.3 g of product, in 85.5% yield. 1 HNMR (500MHz, CDCl3) δ (ppm) = 9.88 (s, 1H), 7.82-7.85 (d, 2H), 6.99-7.02 (d, 2H), 4.35-4.39 (m, 2H), 3.67-3.69 (t, 2H).

[0127] Preparation of 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine (Br-TPY). 2-Acetylpyridine (1.0 mL, 9.2 mmol) was added to a solution of 4-(2-bromoethoxy)benzaldehyde (1.1 g, 4.6 mmol) and methanol (32 mL). Ammonia (29 wt%, 30 mL) and pulverized KOH solid (0.37 g, 9.21 mmol) were simultaneously added to the solution, and a white precipitate rapidly appeared via condensation. The mixture was then stirred at 50 °C for 24 h. The resulting orange suspension was filtered. The off-white solid was washed with H₂O and CH₃OH, and CHCl₃ was added. After solvent evaporation, column chromatography was performed on silica gel using a CH₂Cl₂ / MeOH / Et₃N (volume ratio 100 / 1 / 0.1) mixture as eluent, yielding 935 mg of a white solid in 46.3% yield. 1 HNMR (500MHz, CDCl3) δ (ppm) = 8.79 (d, 2H), 8.76 (s, 2H), 8.72 (dt, 2H), 7.95 ( d,2H),7.93(td,2H),7.41(ddd,2H),7.10(d,2H),4.42(t,2H),3.74(t,2H).

[0128] Preparation of 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide (Py-TPY·Br). Br-TPY (1.0 g, 2.3 mmol) was dissolved in a pyridine solution (50 mL), stirred at 90 °C for 48 h, and subjected to quaternization. After cooling to room temperature, diethyl ether (200 mL) was added to obtain a gray solid. The product was filtered under pressure and washed with diethyl ether, with a yield of 95.8% (1.15 g). 1H NMR (500MHz, DMSO) δ (ppm) = 9.70 (d, 2H), 8.73 (d, 2H), 8.66 (d, 2H), 8.63 (s, 2H), 8.54 (t, 1H), 8.15(t,2H), 7.89(t,2H), 7.80(d,2H), 7.37(ddd,2H), 7.01(d,2H), 5.66(t,2H), 4.70(t,2H)( Figure 3 ). 13 C NMR(DMSO,500MHz,298K)(ppm)=159.18,156.06,155.44,149.74,149.22,146.76,145 .97,137.94,131.06,128.99,128.47,124.97,121.48,117.71,115.91,66.77,60.44.

[0129] [N(C4H9)4]3{MnMo6O 18 Preparation of [(OCH2)3CNHCO(CH2)2COOH]2}(TCMM). Anderson-type polyoxometalate [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6) (1.0 g, 0.55 mmol, 1 eq) and succinic anhydride (1.2 g, 11.1 mmol, 20 eq) were stirred and refluxed in CH3CN (25 mL) for 24 h. After diffusion with diethyl ether, orange crystals (1.3 g) were generated within 24 h via an amide reaction, with a yield of 49%. 1 HNMR (500MHz, DMSO) δ (ppm) = 12.15 (s, 2H), 7.93 (s, 2H), 7.50 (s, 2H), 3.16 (t ,24H),2.71(s,4H),2.31(s,4H),1.57(m,24H),1.31(m,24H),0.94(m,36H).

[0130] (Na)3{MnMo6O 18 Preparation of [(OCH2)3CNHCO(CH2)2COOH]2} (SCMM). TCMM (1.2 g, 0.84 mmol) dissolved in CH3CN (5 mL) was added dropwise to a NaClO4 (5.1 g, 42 mmol) CH3CN (5 mL) solution with vigorous stirring. The solution was then stirred overnight via ion substitution reaction to obtain an orange precipitate. The precipitate was washed twice with acetonitrile to give 0.89 g of the product SCMM, with a yield of 96.9%. 1HNMR (500MHz, DMSO) δ (ppm) = 8.31 (s, 2H), 7.89 (s, 2H), 7.53 (s, 2H), 4.73 (s, 4H), 4.61-4.44 (m, 1 0H),4.29(s,4H),3.91(s,2H),3.78(s,2H),3.53(d,4H),3.06(s,2H),2.70(s,4H),2.31(s,4H).

[0131] (Py-TPY)3{MnMo6O 18 Preparation of [(OCH2)3CNHCO(CH2)2COOH]2} (PCMM). The obtained SCMM (0.8 g, 0.4 mmol) was dissolved in a 1:1 V / V mixed solvent (20 mL) of CH3OH / H2O, and then mixed with a solution of Py-TPY·Br (0.6 g, 1.2 mmol) (CH3OH / H2O 1:1 V / V, 10 mL). The mixture was stirred overnight by ion substitution reaction, resulting in an orange-gray precipitate. The precipitate was washed twice with CH3OH to give 1.3 g of product, with a PCMM yield of 93.4%. 1 H NMR (500MHz, DMSO) δ (ppm) = 9.19 (d, 6H), 8.76 (d, 6H), 8.67 (d, 16H), 8.31 ( s,2H),8.23(t,6H),8.05(t,6H),7.92(d,6H),7.91(s,2H),7.54(t,6H),7. 15(d,6H),5.11(t,6H),4.73(s,4H),4.64(t,6H),4.62-4.40(m,10H),4.2 9(s,4H),3.92(s,2H),3.62(s,2H),3.54(d,4H),2.72(s,4H),2.32(s,4H). 13 C NMR (DMSO, 500MHz, 298K) (ppm) = 173.44, 171.80, 159.05, 156.13, 155.45, 149.79, 149.31, 146.67, 146.03, 137.99, 130.95, 128.84, 128.5 7. 124.97, 123.85, 121.43, 117.83, 115.92, 100.31, 74.60, 71.33, 70 .48, 67.33, 66.84, 65.43, 61.62, 60.70, 49.81, 34.88, 31.75, 29.65.

[0132] Elemental analysis calculations for (C 28 H 23ON4)3MnMo6O 24 C 16 H 24 O6N2·3H2O(PCMM,2703.507g·mol -1 Theoretical values: C 44.43%; H 3.69%; N 7.25%; Mn 2.03%; Mo 21.29%; Experimental values: C 44.29%; H 3.81%; N 7.37%; Mn 1.98%; Mo 21.09%.

[0133] Preparation and characterization of SF.

[0134] The synthesized PCMM and ZnSO4 were dissolved separately in a DMF / H2O solution (volume ratio 1:1). Then, they were mixed at a molar ratio of 2:3 (PCMM:ZnSO4) to form 2D SF( Figure 2 The pH was adjusted to 3 by adding H2SO4 (1M), and the cells were further grown into 3D SF. The separated SF assemblies were allowed to stand at room temperature for 3.0 h, filtered, washed with H2O and dried. The coordination binding ratio and molar ratio of the 3D SF assemblies were consistent by inorganic and organic elemental analysis (Table 1).

[0135] Table 1 Inorganic and organic elemental analysis of 3D SF

[0136]

[0137] The coordination of zinc ions with terpyridine in the ionic complex was characterized by X-ray photoelectron spectroscopy (XPS). Figure 3 Image a shows the XPS spectrum of the 2D SF assembly of PCMM and PCMM-ZnSO4, and image b shows the FT-IR spectrum of the 2D SF assembly of PCMM and PCMM-ZnSO4, where Zn 2p is observed. 1 / 2 and 2p 3 / 2 The binding energy decreased by 1.2 eV, indicating that zinc ions participated in coordination. Figure 3 (a) Simultaneously adding Zn 2+ Later, at 1607 and 1443cm -1 The FT-IR spectral vibrational bands corresponding to the stretching of C=N and CN bonds shift to lower wavenumbers at 1601 and 1433 cm⁻¹. -1 This indicates the formation of N-Zn coordination ( Figure 3 (b)

[0138] Figure 4 For a complexometric titration experiment, where a is the ratio of the components in [Zn] to the total weight of the components. 2+[PCMM] When the molar ratios are 0:1, 0.1:1, 0.2:1, 0.3:1, 0.6:1, 0.9:1, 1.2:1, 1.5:1, 1.8:1, 2.1:1, 2.4:1, and 2.7:1, the Zn content in DMF / H2O (volume ratio 1:1) 2+ The UV-Vis titration spectra of PCMM, where b is the value of [Zn] 2+ [PCMM] The increase in the molar ratio corresponds to the absorption Job plot at 340 nm. It can be seen that an absorption band appears in the UV-Vis spectrum at 340 nm, corresponding to the charge transfer transition from metal to ligand, further confirming the interaction between the complex and Zn. 2+ Coordination relationship ( Figure 10 In section a), as the molar ratio increases, the absorption band at 340 nm increases until the molar ratio reaches 3:2, indicating that PCMM and Zn... 2+ Complete coordination ( Figure 10 (b)

[0139] Characterization and properties of 2D SF and 3D SF

[0140] Characterization of 2D SF

[0141] When the pH value is 7, transmission electron microscopy (TEM) images show that the formed supramolecular assemblies exist as nanoribbon-like structures with lengths of hundreds of micrometers and widths of tens of nanometers. Figure 5 (a-b). Atomic force microscopy (AFM) measurements show that the average height of the nanoribbons is approximately tens of nanometers ( Figure 5 (c) The X-ray diffraction (XRD) pattern shows multiple diffraction corresponding to different crystal planes, indicating that it has a hexagonal framework structure. The diffraction peaks with 2θ angles of 4.98, 5.80, 6.21, 7.66, 8.98, 9.86, 10.25, 12.58, and 17.48 coincide with a hexagonal aperture of approximately 6.0 nm, and the diffraction indices are (300), (220), (310), (410), (420), (600), (430), (620), and (840), respectively. Figure 5 (d). Since the carboxyl groups exist partially in a salt state at pH 7, there are very few hydrogen bond orientation arrays, and the assembly in the c-axis direction is disordered.

[0142] Characterization of 3D SF.

[0143] When the pH is adjusted to 3, the assemblies become more rigid due to the formation of hydrogen bonds between the carboxylic acid dimers, transforming from a nanoribbon structure to a nanorod structure, as shown in the TEM image. Figure 6 (a). The lattice fringes in the TEM image reveal a three-dimensional structure based on the (111) surface spacing, molecular model, and XRD indices. Figure 6(b) Diffraction indices (111), (222), and (333) were detected in the selected region by electron diffraction (SAED). Figure 6 (See inset b). The calculated d values ​​were 2.0, 1.0, and 0.7 nm, with a ratio of 1:1 / 2:1 / 3, further confirming the existence of the three-dimensional structure. Additional electron diffraction patterns were also observed on other crystal planes such as 300, 302, 402, and 410. In further magnified images, a dark region of heavy electron density with a size of approximately 0.8–1.0 nm was observed, which can be attributed to inorganic clusters (0.3 nm × 0.9 nm). Figure 6 (c) In the AFM images, the assembly height can be seen increasing from tens of nanometers to hundreds of nanometers. Figure 6 (d). Polarized light microscopy images further confirmed the nanorods and their excellent crystallinity ( Figure 6 (e). XRD data show additional diffraction peaks on different crystal planes such as (111), (222), (333), and (444), indicating that the three-dimensional stacked structure originates from a two-dimensional layered assembly. The calculated d values ​​are 20.2, 10.0, 6.8, and... The ratio is 1:1 / 2:1 / 3:1 / 3:1 / 4, further revealing the three-dimensional packing structure. Figure 6 (f). Nitrogen adsorption results showed that a distinct peak with a pore size of 3.5 nm represented the length of interlayer pores, and a shoulder peak with a pore size of 5.9 nm represented the inner hexagonal pores of the 3D SF module, consistent with XRD distribution. Figure 6 (g). Based on these results, schematic diagrams of the pore structure of 3D SF in the ab- and ac-plane directions are shown below. Figure 6 As shown in h and i. Furthermore, diffraction peaks (201), (601), (611), and (602) also verify the ordered nature of the 3D SF structure. Figure 7 At low pH, the FT-IR spectrum shows a peak at 1728 cm⁻¹. -1 The vibration band (attributed to the stretching vibration of -COOH) shifted to 1684 cm. -1 This indicates the formation of hydrogen-bonded dimers ( Figure 8 2D SF grows into 3D SF through the formation of hydrogen bonds. Figure 9 ).

[0144] Example 2

[0145] 3D SF was grown in situ on a Zn anode.

[0146] A dense and continuous ASEI protective layer 3D SF was assembled on a zinc sheet using a simple in-situ growth method. This protective layer adheres tightly to the zinc electrode surface by forming coordination bonds, ensuring the integrity of the interface during battery operation. The in-situ method was accomplished by directly immersing the zinc sheet in an ion complex (PCMM) solution at pH 3. The specific preparation method is as follows: 10 mg of PCMM molecules were dissolved in a 20 mL LMF and water (volume ratio 1:1) mixture, and 20 zinc sheets were partially inserted into the solution. SEM images showed that nanorods with a framework structure initially appeared and randomly stacked on the zinc sheet. Figure 10 (a) As reaction time increases, due to the adaptability and flexibility of the assembly, the nanorods gradually fuse into nanosheets. Figure 10 (b) Ultimately, all the nanorods fuse together to form a dense, continuous SF layer (called 3D SF / Zn) with a flat surface. Figure 10 (c) By controlling the assembly time, a smooth SF layer can achieve a thickness of 3μm. Figure 10 (d and e). XPS verified the composition of Mn, Mo, Zn, C, N and O elements within the protective layer ( Figure 10 (f). Energy dispersive X-ray spectroscopy (EDX) images show a uniform distribution of Mn, Mo, and C elements in this layer, further confirming the homogeneity of the three-dimensional SF heterostructure. Figure 10 (g~j). By comparing the XRD results of 3D SF in solution, the c-axis diffraction of 3D SF ASEI almost disappeared ( Figure 11 This indicates that the growth of the skeleton on the zinc sheet mainly occurs in a plane parallel to the ab plane of the zinc sheet.

[0147] SEI characterization of zinc anode.

[0148] To confirm the inhibitory effect of the 3D SF artificial layer on Zn dendrite growth, the Zn deposition morphology was monitored using in-situ optical microscopy. After 20 minutes, uneven zinc plating protrusions began to appear at the edges of the exposed zinc electrode. Figure 12 (a) and gradually transforms into zinc dendrites. In contrast, even after 60 min, the interface of the 3D SF / Zn electrode remained smooth, with no signs of protrusions or zinc dendrites observed. Figure 12 (b) To further reveal the effect of 3D SF on Zn deposition, a 3D SF semi-coated zinc anode was prepared. The specific preparation method is as follows: 10 mg of PCMM molecules were dissolved in a mixed solution of 20 mL of LDM and water (volume ratio 1:1), and 40 zinc sheets were added to the solution for semi-insertion. After zinc deposition, a rough dendritic surface appeared in the exposed Zn region, while the coated region remained smooth without obvious dendrite formation. Figure 12 c, d and Figure 13This indicates that the 3D SF module ensures uniform Zn deposition. SEM characterization was used to evaluate the surface morphology evolution of the electrode during battery cycling. After 10 and 30 cycles, the exposed Zn surface became rougher. Figure 14 (a~d). During 100 cycles, a large number of dendrites formed ( Figure 14 (e and f). Conversely, after 10, 30, and 100 cycles, the 3D SF / Zn surface remained flat and smooth, further demonstrating that 3D SF modulates the uniform nucleation and deposition of Zn. Figure 14 The crystal orientation on the cyclic electrode was detected using XRD patterns. The intensity ratio of the (002) peak to the (100) peak in 3D SF / Zn gradually increased from 3:1 after 10 cycles to 5:1 after 100 cycles, indicating that 3D SF dominated the preferential orientation of the Zn (002) plane. For bare Zn, the intensity ratio of (002) to (100) remained unchanged during cycling, leading to Zn dendrite elongation ( Figure 12 e, f and Figure 15 Based on the above analysis, the schematic diagram ( Figure 12 (g) depicts the crystallization process and corresponding morphological evolution of Zn anodes with and without three-dimensional SF layers.

[0149] The study verified that uniform growth of 3D SF on the zinc anode surface is beneficial to the formation of ordered nanochannels, and that negatively charged POM nodes can modulate Zn. 2+ The diffusion behavior of ions was investigated using electrochemical tests. Due to the hydrophilicity of POM, 3D SF / Zn exhibited considerably high hydrophilicity, with a contact angle of 18.6°, significantly smaller than that of bare Zn (84.1°). Figure 16 a and Figure 17 (a to d). This high hydrophilicity allows for rapid electrolyte penetration and ion diffusion across the assembled layer. Based on a simple model established by Extrand, the wetting free energy of these two electrodes is calculated using the following equation:

[0150]

[0151] In the formula, R, T, and θ represent the ideal gas constant, absolute temperature, and contact angle, respectively. The calculated absolute value ΔG for the 3D SF / Zn anode is 5130 J·mol⁻¹. -1 It far exceeds that of bare Zn (710 J·mol⁻¹) -1 ()( Figure 16 b and Figure 17 (e). This indicates that the incorporated POM clusters improve wettability and enhance Zn. 2+ It plays a crucial role in diffusion at the electrolyte / electrode interface. The abundant POM and carboxyl groups on the 3D SF surface and internal channels provide an electronegative zeta potential of -12.9 mV. Figure 16 (c) This facilitates the passage of zinc ions. The reduced molybdenum in the POM further increases the electronegativity of the framework, as shown in XPS spectroscopy. Figure 16 (d) indicates that MnMo6O is present in 3D SF assembly. 19 Partial restoration, in which Mo 6+ After the cycle, it becomes Mo. 5+ Generating more net negative charge is beneficial for accelerating Zn production. 2+ The diffusion kinetics of the Zn anode were investigated. Time-current measurements revealed that the 3D SF / Zn anode underwent a two-dimensional diffusion process lasting 25 s, followed by a sustained three-dimensional diffusion process. This three-dimensional diffusion ultimately resulted in a smooth and dense zinc layer. In stark contrast, the current density of the bare zinc cell dropped sharply to around -48 mA after 400 s, indicating that the two-dimensional diffusion of Zn ions was uncontrollable, which contributed to the formation of Zn dendrites. Figure 16 (e). XRD results show that the 3D SF protective layer can effectively suppress the formation of 3DSF / Zn and Bare Zn byproduct energies (e). Figure 18 After cycling, zinc hydroxide sulfate (Zn4SO4(OH)6·4H2O) was observed on the bare Zn surface, while the diffraction peaks of this byproduct on the 3D SF / Zn surface were negligible. Cyclic voltammetry (CV) curves showed that 3D SF / Zn exhibited a higher response current density and a lower nucleation overpotential compared to bare Zn, confirming that the 3D SF / Zn electrode possesses superior reaction kinetics. Figure 19 Zn in 3D SF / Zn anodes 2+ The migration number was 0.86, significantly higher than the 0.39 of the bare zinc anode. Figure 16 f and Figure 20 This further proves the Zn content of the 3D SF / Zn component. 2+ Enhanced migration properties. Furthermore, 3DSF / Zn exhibits improved ionic conductivity compared to bare zinc in aqueous electrolytes. Figure 21 (a) The effect of three-dimensional SF on the surface limiting current was evaluated using the linear sweep voltammetry (LSV). The 148 mA value of 3D SF / Zn is significantly higher than that of bare Zn (99 mA). Figure 21 Figure b) shows that the surface negative charge of porous 3D SF enhances the limiting current on the Zn electrode, thereby effectively suppressing dendrite formation.

[0152] The 3D SF-accelerated Zn was investigated using density functional theory (DFT). 2+ The working mechanism of transportation. For example... Figure 16As shown in Figure g, the migration path between the two hydrogen-bonded POMs exhibits an energy barrier of approximately 1.37 eV, indicating that the continuous and ordered POMs in the 3D SF channel facilitate the rapid directional transport of Zn ions. The activation energy of Zn on the Zn(002) surface is only 0.19 eV, suggesting that the diffusion of Zn on the Zn(002) surface is essentially instantaneous, which is conducive to the formation of heterogeneous moss-like Zn deposits. Figure 22 In contrast, 3D SF has a higher activation energy (-1.89 eV). Figure 16 (middle h). 3D SF high Zn 2+ The diffusion barrier prevents Zn from spreading to some extent. 2+ The instantaneous diffusion and aggregation of Zn act as a regulating layer, which is more conducive to Zn. 2+ Uniform diffusion is achieved. Simultaneously, the high binding energy indicates a strong zinc affinity at the anode / electrolyte interface, which helps improve the redox kinetics of the anode. The combination of high adsorption energy and a surface diffusion barrier enables the 3D SF / Zn anode to suppress zinc dendrite formation.

[0153] Zinc ion transfer number (t) Zn 2+ ) Calculated by the following formula:

[0154]

[0155] In the formula, ΔV is the applied constant polarization voltage (10mV), the initial current I0 is 0.031mA for bare Zn and 0.038mA for 3D SF / Zn, the initial resistance R0 is 269Ω for bare Zn and 201Ω for 3D SF / Zn, and the steady-state current I... s The bare Zn current is 0.017 mA, the 3DSF / Zn ratio is 0.023 mA, and the steady-state resistance R0 is... s Bare Zn has an Ω rating of 474Ω, while 3D SF / Zn has an Ω rating of 354Ω.

[0156] Electrochemical performance of 3D SF / Zn anodes

[0157] Adding POM clusters to 3D SF can promote Zn 2+ The diffusion and uniform deposition of the 3D SF / Zn and bare Zn electrodes were investigated in symmetric cells at different current densities. Compared with the bare zinc symmetric cell, the 3D SF / Zn symmetric cell exhibited better diffusion and uniform deposition at 5 and 10 mA·cm⁻¹. -2 Both exhibited stronger long-term cycling stability. The 3D SF / Zn battery at 5 mA·cm⁻¹ showed... -2 Under these conditions, the battery exhibited stability and low overpotential after more than 7500 cycles within 3000 hours. In contrast, the bare zinc battery only experienced a sudden voltage drop after 470 hours, indicating a short circuit. Figure 23 (a) At 10 mA·cm-2 At higher current densities, 3D SF / Zn can cycle stably with minimal voltage fluctuations exceeding 1500 hours. Figure 24 To evaluate the impact of 3D SF ASEI on Zn reversibility, coulombic efficiency (CE) was tested by measuring bare Zn||Cu and 3D SF / Zn||Cu cells. The 3D SF / Zn||Cu cell achieved a CE of 5 mA·cm⁻¹. -2 The average CE was 99.86% during 4800 cycles, and the cycle capacity was 1 mAh·cm³. -2 ( Figure 25 The bare Zn||Cu battery exhibited poor performance after 700 cycles, with significant fluctuations in CE. (At 10 mA·cm⁻¹) -2 Below, the polarization voltage of the Zn||Cu cell decreases from 86mV ( Figure 26 The polarization voltage gradually increased from 144 mV (in the first cycle) to 144 mV (in the 400th cycle), indicating an increase in internal resistance caused by side reactions and Zn dendrites. In contrast, the polarization voltage of the 3D SF / Zn||Cu battery stabilized at 96 mV after more than 4500 cycles. Figure 26 (b) 3D SF / Zn||Cu cells maintain a high average CE of 99.91% after 4500 cycles. Figure 23 b). Conversely, at 10 mA·cm -2 The Zn||Cu cell failed only after 420 cycles, indicating uneven zinc plating / stripping without a 3DSF layer. Furthermore, the 3D SF / Zn anode exhibited poor performance at 5–50 mA·cm⁻¹. -2 The constant current cycling curves at current density show excellent rate performance. Typically, the constant current cycling is at 5 mA·cm⁻¹. -2 It maintains stability for more than 2500 hours at current density. Figure 27 ), superior to most reported zinc anodes ( Figure 28 ).

[0158] The electrochemical performance of the 3D SF / Zn electrode in a Zn||MnO2 battery was further characterized. (0.1 mV·s) -1 Below, the CV curves of bare Zn||MnO2 and 3D SF / Zn||MnO2 show two pairs of redox peaks, corresponding to the influx and outflow of protons and Zn ions. Figure 29 (a) The 3D SF / Zn||MnO2 cell exhibits a higher peak current (0.66 mA) and a narrower redox peak gap than the bare Zn||MnO2 cell, indicating faster reaction kinetics and lower anodic polarization. The 3D SF / Zn full cell demonstrates better rate performance than the bare zinc cell. Figure 29 (b) In 0.2A·g -1At low current densities, the average capacity of the two batteries is similar, at ~300 mAh·g. -1 When the current density increases to 3 A·g -1 At that time, the specific capacity of the 3D SF / Zn battery reached 145.7 mAh·g. -1 The average specific capacity of bare Zn batteries is only 71.2 mAh·g. -1 For sustainability, the 3D SF / Zn full cell offers a high initial capacity (157.5 mAh·g). -1 It remained at 135.4 mAh·g after 1000 cycles. -1 , in 1A·g -1 The retention rate was 86%. On the other hand, due to dendrite formation and side reactions, the bare Zn||MnO2 cell at 1 A·g -1 The capacity decays rapidly, and after 1000 cycles, only 40% of the capacity remains. Figure 23 c). EIS spectrum of the initial full cell ( Figure 27 As shown in d), the resistance of a fully charged 3DSF / Zn cell is much lower than that of bare Zn, indicating that it is beneficial for rapid charge transfer. At 1 A·g -1 After 100 cycles, the 3D SF / Zn anode in the full cell remained smooth and intact. In contrast, the bare zinc anode became porous and composed of flakes. Figure 23 (e and f). These results further demonstrate the superior performance and stability of the 3D SF / Zn anode in full cells.

[0159] Figure 29 The results are for the full cell electrochemical calculation, where a is 0.1 mV·s. -1 The CV curve at time b is 0.2–3 A·g. -1 Rate performance.

[0160] Figure 30 This document describes the preparation of SF assemblies and their negatively charged ion channels. Figure a shows the structural diagrams of the prepared carboxyl-grafted cluster SCMM, the cationic ligand Py-TPY, and its ion complex PCMM. Figure b shows the process of passing Zn through DMF / H2O (volume ratio 1:1) at pH 3 (or 7). 2+ This invention provides a schematic diagram of in-situ growth of 3D SF on a Zn anode in DMF / H2O (volume ratio 1:1) at pH 3, with coordination to prepare 3D (or 2D) SF, and an ordered POM cluster providing zinc ion transfer channels. The invention utilizes the electrostatic and covalent modification of POM and the coordination between ligands and zinc ions to design a POM-functionalized 3D SF. Figure 30In section a), a uniform 3D SF ASEI layer was constructed on a Zn anode using an in-situ growth method. The 3D SF protective layer offers several advantages. The multiple interactions involved in constructing the 3D SF protective layer on the zinc anode, including coordination, hydrogen bonding, electrostatic interactions, and covalent bonds, contribute to the structural stability and integrity of the ASEI protective layer during battery operation. Forming a uniform, seamless 3D SF layer on the Zn anode surface isolates the Zn anode from direct contact with the aqueous electrolyte, thereby suppressing side reactions. The crystalline 3D SF possesses an ultra-large nanoscale ordered pore structure of 6 nm, which is beneficial for Zn... 2+ Rapid and uniform transport, and based on Zn 2+ The three-dimensional diffusion induces the dominant growth of the Zn(002) crystal plane, resulting in the uniform deposition of zinc ions. Figure 30 (b) In 3D SFs, the reduction of uniformly distributed POM established negatively charged ion diffusion nanochannels, which not only accelerated the diffusion of Zn... 2+ The diffusion kinetics of Zn are impeded, and the migration of sulfate ions is hindered. 2+ The migration number reached 0.86. DFT simulations showed that zinc ions have a good transport pathway along the three-dimensional orientation of the framework during deposition. Therefore, the 3D SF / Zn anode exhibited a migration rate exceeding 3000 h (5 mA·cm⁻¹). -2 1mAh·cm -2 Long-term cycling stability and more than 4800 cycles (5mA·cm) -2 1mAh·cm -2 Furthermore, it exhibits ultra-high reversibility with an average CE of 99.86%. This type of Zn exhibits rapid reversibility. 2+ The 3D SFs ASEI layer design for the transmission channel opens up new strategies for developing high-performance Zn anodes.

[0161] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an ionic complex, characterized in that, Includes the following steps: A bromination reaction was carried out by mixing p-hydroxybenzaldehyde, 1,2-dibromoethane and an organic solvent to obtain 4-(2-bromoethoxy)benzaldehyde; The 4-(2-bromoethoxy)benzaldehyde, 2-acetylpyridine, ammonia, an inorganic alkaline substance, and an organic solvent were mixed and subjected to a condensation reaction to obtain 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine; The 4′-[4-(2-bromoethoxy)phenyl]-2,2′:6′,2′-terpyridine and pyridine were mixed and subjected to a quaternization reaction to obtain 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)bromopyridine; An amide reaction was carried out by mixing an Anderson-type polyoxometalate, succinic anhydride, and an organic solvent to obtain an amide product. The Anderson-type polyoxometalate is [N(C4H9)4]3{MnMo6O 18 [(OCH2)3CNH2]2}(MnMo6); The amide product, a soluble inorganic metal salt, and an organic solvent are mixed to carry out a first ion substitution reaction to obtain the first ion substitution product. The first ion-substitution product, 1-(2-(4-([2,2':6',2'-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide, and solvent were mixed to carry out a second ion-substitution reaction to obtain the ion complex; The soluble inorganic metal salt is an alkali metal inorganic salt; The ionic complex is (Py-TPY)3{MnMo6O 18 [(OCH2)3CNHCO(CH2)2COOH]2}.

2. The preparation method according to claim 1, characterized in that, The molar equivalent ratio of the Anderson-type polyoxometalate to succinic anhydride is 1:

20.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the amide product to the alkali metal inorganic salt is 1:

50.

4. The preparation method according to claim 1, characterized in that, The molar ratio of the first ion-substituted product to 1-(2-(4-([2,2':6',2′-terpyridine]-4'-yl)phenoxy)ethyl)pyridine bromide is 1:

3.

5. The ionic complex prepared by the method according to any one of claims 1 to 4.

6. The application of the ionic complex according to claim 5 in zinc metal anodic protection.

7. An artificial solid electrolyte interface phase, characterized in that, It is prepared by a method including the following steps: immersing a zinc sheet in a solution for in-situ growth to form a three-dimensional supramolecular framework assembly, wherein the solute in the solution is the ionic complex of claim 5.

8. A zinc metal anode, characterized in that, It includes a zinc anode substrate and an artificial solid electrolyte interface phase loaded on the surface of the zinc anode substrate, wherein the artificial solid electrolyte interface phase is the artificial solid electrolyte interface phase as described in claim 7.

9. The application of the ionic complex according to claim 5 in the preparation of supramolecular framework assemblies.

10. A supramolecular framework assembly, characterized in that, It is obtained by coordination of the ionic complex described in claim 5 and zinc ions.

Images