Battery cell and method for producing the same, battery device, electric device, energy storage device

Abstract

This invention provides a battery cell, its preparation method, a battery device, an electrical device, and an energy storage device. The battery cell includes a gel polymer electrolyte layer located between a positive electrode and a negative electrode. The gel polymer electrolyte comprises a metal propeller complex, a nitrogen-terminated polyether polymer, a lithium salt, and a plasticizer; wherein the metal propeller complex has a D... 4h A symmetrical binuclear metal carboxylic acid complex, with the general chemical formula M2(O2CR)4, wherein M is zinc and / or copper, -O(O)CR is a bridging carboxylate ligand, and R includes an oligomeric ether oxygen segment; the end groups of the nitrogen-terminated polyether polymer are nitrogen-containing heterocyclic groups; and the axial sites of M in the binuclear metal carboxylic acid complex are connected to the nitrogen-containing heterocyclic groups of the nitrogen-terminated polyether polymer through coordinate bonds, thus solving the problem in the prior art that polymer electrolytes are difficult to possess both excellent mechanical properties and ion conduction properties.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage technology, and more specifically, to a battery cell and its preparation method, a battery device, an electrical device, and an energy storage device. Background Technology

[0002] Lithium-ion batteries, as the most important electrochemical energy storage technology today, have been widely used in consumer electronics, electric vehicles, and large-scale energy storage. With the rapid development of the energy storage market, the requirements for battery safety, cycle life, and cost are constantly increasing. As one of the core components of a battery, technological advancements in the electrolyte are crucial to meeting these requirements.

[0003] While traditional liquid electrolytes possess high ionic conductivity and good electrode wettability, they also have inherent drawbacks such as flammability, leakage susceptibility, and a limited electrochemical window, which pose significant safety risks, especially in large-capacity energy storage applications. Polymer electrolytes, as a crucial alternative to liquid electrolytes, offer advantages such as non-flammability, leak resistance, and high design flexibility, and are considered an important technological approach for improving the intrinsic safety of batteries.

[0004] The development of polymer electrolytes has evolved from pure solid polymer electrolytes to gel polymer electrolytes. Pure solid polymer electrolytes, represented by polyethylene oxide, rely on the movement of polymer chain segments for ion conduction and typically exhibit low conductivity at room temperature. Gel polymer electrolytes, by introducing plasticizers or liquid electrolytes, significantly improve ionic conductivity while retaining the structural support function of the polymer, making them a promising technology for engineering applications.

[0005] However, further development of polymer electrolytes faces a fundamental contradiction between mechanical properties and ion conductivity. To improve mechanical strength and suppress lithium dendrite growth, polymer cross-linking is typically required, but cross-linking restricts chain segment movement and reduces ion conductivity. Maintaining high ion conductivity while preserving good mechanical properties has become a core challenge in the field of polymer electrolytes. In recent years, metal-organic frameworks have attracted widespread attention in the field of solid-state electrolytes, but their rigid crystalline structure and the resulting processing difficulties and interface problems limit their practical applications.

[0006] Therefore, there is an urgent need to develop a novel polymer electrolyte that combines rigid structural support with flexible ion transport properties, in order to solve the problem that existing polymer electrolytes cannot simultaneously possess excellent mechanical properties and ion conduction performance. Summary of the Invention

[0007] The main objective of this invention is to provide a battery cell and its preparation method, battery device, power supply device, and energy storage device, so as to solve the problem that polymer electrolytes in the prior art are difficult to have both excellent mechanical properties and ion conduction properties.

[0008] To achieve the above objectives, according to one aspect of the present invention, a battery cell is provided, comprising a positive electrode, a negative electrode, and a gel polymer electrolyte layer located between the positive and negative electrode. The gel polymer electrolyte layer comprises a gel polymer electrolyte, which includes a metal propeller complex, a nitrogen-terminated polyether polymer, a lithium salt, and a plasticizer; wherein the metal propeller complex is a polymer with a D... 4h A symmetrical binuclear metal carboxylic acid complex, the general chemical formula of which is M2(O2CR)4, wherein M is zinc and / or copper, -O(O)CR is a bridged carboxylate ligand, and R includes an oligomeric ether oxygen segment; the end group of the nitrogen-terminated polyether polymer is a nitrogen-containing heterocyclic group; and the axial site of M in the binuclear metal carboxylic acid complex is connected to the nitrogen-containing heterocyclic group of the nitrogen-terminated polyether polymer through a coordinate bond.

[0009] Furthermore, the aforementioned -O(O)CR is CH3O(CH2CH2O). n CH2C(O)O-, where n is the number of repeats of the ether oxygen unit, and n is any integer from 1 to 6.

[0010] Furthermore, the aforementioned nitrogen-terminated polyether polymer is a polyoxyethylene containing a nitrogen-containing heterocyclic group, wherein the nitrogen-containing heterocyclic group is selected from any one of pyridinyl, imidazolyl, and triazolyl.

[0011] Furthermore, the number-average molecular weight of the aforementioned polyethylene oxide is between 400 g / mol and 10,000 g / mol.

[0012] Furthermore, the lithium salt is selected from any one or more of lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, and lithium perchlorate.

[0013] Furthermore, the molar ratio of lithium ions in the lithium salt to ether radical groups in the polyethylene oxide is 1:8 to 1:20.

[0014] Furthermore, the mass percentage of the aforementioned metal propeller complex in the gel polymer electrolyte is 1% to 30%.

[0015] Furthermore, the plasticizer is selected from any one or more of ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, ionic liquids and polyethers; and / or, the content of the plasticizer is 5% to 30% of the total mass of the gel polymer electrolyte.

[0016] Furthermore, the thickness of the aforementioned gel polymer electrolyte layer is 10 to 100 micrometers.

[0017] According to another aspect of the present invention, a battery device is provided, the battery device comprising the aforementioned battery cell, and the battery device comprising one or more of the following: battery module, battery pack, and energy storage battery.

[0018] According to another aspect of the present invention, an electrical device is provided, which includes the aforementioned battery device for providing electrical energy.

[0019] According to another aspect of the present invention, an energy storage device is provided, the energy storage device including the aforementioned battery device, the battery device being used to store electrical energy.

[0020] Applying the technical solution of this application, the gel polymer electrolyte layer in this application adopts a D-type... 4h The unique molecular geometry of the symmetrical binuclear metal carboxylic acid complex serves as a rigid molecular-level cross-linking node. Simultaneously, the bridging carboxylic acid ligands of the metal propeller complex employ a functionalized monocarboxylic acid structure with oligoether oxygen side chains, ensuring that each carboxylic acid molecule coordinates only with a metal atom in one propeller unit, avoiding the formation of an infinitely extended coordination network. This allows the propeller to maintain a discrete molecular state while enhancing the local ion solubilization environment through the ether oxygen groups in the side chains, improving the continuity of lithium-ion transport. Therefore, the nitrogen-terminated polyethylene oxide and the axial coordination sites of the metal propeller complex form a controllable three-dimensional coordination cross-linking network, achieving topological integration of rigid inorganic nodes and flexible organic segments. This provides mechanical stability while maintaining the mobility of polymer segments, overcoming the technical bottleneck of traditional polymer electrolytes that struggle to balance high toughness and high ionic conductivity. This provides an electrolyte solution for energy storage lithium-ion batteries with synergistically optimized mechanical and electrochemical performance. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A process flow diagram for preparing a gel polymer electrolyte membrane according to Embodiment 1 of the present invention is shown. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] As analyzed in the background section of this application, there is a problem that polymer electrolytes in the prior art cannot simultaneously possess excellent mechanical properties and ion conduction properties. In order to solve this problem, this application provides a battery cell and its preparation method, a battery device, an electrical device, and an energy storage device.

[0025] In one typical embodiment of this application, a battery cell is provided, including a positive electrode, a negative electrode, and a gel polymer electrolyte layer located between the positive and negative electrode. The gel polymer electrolyte layer includes a gel polymer electrolyte comprising a metal propeller complex, a nitrogen-terminated polyether polymer, a lithium salt, and a plasticizer; wherein the metal propeller complex is a D-type polymer. 4h A symmetrical binuclear metal carboxylic acid complex, the general chemical formula of which is M2(O2CR)4, wherein M is zinc and / or copper, -O(O)CR is a bridged carboxylate ligand, and R includes an oligomeric ether oxygen segment; the end group of the nitrogen-terminated polyether polymer is a nitrogen-containing heterocyclic group; and the axial site of M in the binuclear metal carboxylic acid complex is connected to the nitrogen-containing heterocyclic group of the nitrogen-terminated polyether polymer through a coordinate bond.

[0026] In this application, the gel polymer electrolyte layer uses a D-type... 4h The unique molecular geometry of the symmetrical binuclear metal carboxylic acid complex serves as a rigid molecular-level cross-linking node. Simultaneously, the bridging carboxylic acid ligands of the metal propeller complex employ a functionalized monocarboxylic acid structure with oligoether oxygen side chains, ensuring that each carboxylic acid molecule coordinates only with a metal atom in one propeller unit, avoiding the formation of an infinitely extended coordination network. This allows the propeller to maintain a discrete molecular state while enhancing the local ion solubilization environment through the ether oxygen groups in the side chains, improving the continuity of lithium-ion transport. Furthermore, the nitrogen-terminated polyethylene oxide forms a controllable three-dimensional coordination cross-linking network with the axial coordination sites of the metal propeller complex, integrating rigid inorganic nodes with flexible organic segments. This provides mechanical stability while maintaining the mobility of polymer segments, overcoming the technical bottleneck of traditional polymer electrolytes that struggle to balance high toughness and high ionic conductivity. This provides an electrolyte solution for energy storage lithium-ion batteries with synergistically optimized mechanical and electrochemical performance.

[0027] In some embodiments of this application, the -O(O)CR mentioned above is CH3O(CH2CH2O). n CH2C(O)O-, where n is the number of repeats of the ether oxygen unit, and n is any integer from 1 to 6.

[0028] The etheroxy groups on the ligand side chains not only help provide a local solvation environment for lithium ions, reducing their migration activation energy, but also enhance the solubility and dispersibility of the metal propeller complex in the polymer matrix and plasticizer, forming a uniform cross-linked network. Preferably, the number of repeating etheroxy units, n, is within the above range, which is beneficial for the ligand to maintain stable coordination with the metal while providing sufficient etheroxy groups to improve the local ion transport environment, thus contributing to a better balance between the ligand's coordination stability and ion solvation function. Preferably, n is any integer from 2 to 4; more preferably, n is any integer from 2 to 3.

[0029] In some embodiments of this application, the nitrogen-terminated polyether polymer is a polyoxyethylene containing a nitrogen-containing heterocyclic group, which is selected from any one of pyridyl, imidazole and triazole groups.

[0030] The aforementioned nitrogen-terminated polyether polymers form a cross-linked network through coordination between the end groups and the axial sites of the propeller. The nitrogen-containing heterocycles have good coordination ability with the axial sites of zinc or copper, and the resulting coordination bonds have moderate strength, which can maintain the stability of the cross-linked network while retaining a certain degree of dynamism. The lone pair electrons of the pyridine nitrogen atom have good coordination ability, and the coordination bonds formed with zinc or copper are highly stable and reversibly controllable, which helps to form stable and reversible coordination bonds with the axial sites of zinc or copper in the metal propeller complex. This results in the construction of a uniform and dynamic cross-linked network inside the gel polymer electrolyte. At the same time, since the aforementioned nitrogen-containing heterocyclic groups have good thermal stability and chemical inertness, they help to reduce the side reactions or electrolyte decomposition problems that may be caused by other nitrogen-containing groups, thus improving the reliability of long-term cycling over a wide electrochemical window.

[0031] Furthermore, the nitrogen-terminated polyether polymer is an α,ω-bi-terminated nitrogen-containing heterocyclic polyether, meaning that both ends of the polyether chain have nitrogen-containing heterocyclic groups (such as pyridinyl or imidazole groups). The metal propeller complex has two axial coordination sites along the C4 axis (located at both ends of the binuclear M2 unit). The α,ω-bi-terminated nitrogen-containing heterocyclic polyether forms coordination bonds with the axial sites of two different metal propeller complexes through its nitrogen-containing heterocyclic groups at both ends, thereby connecting adjacent propeller nodes in a double-bridge manner. Multiple polyether chains and multiple metal propeller complexes extend stepwise through this bi-terminated coordination topological connection, thereby constructing a three-dimensional coordination crosslinking network.

[0032] In some embodiments of this application, the number average molecular weight of the above-mentioned polyethylene oxide is from 400 g / mol to 10000 g / mol.

[0033] When the number-average molecular weight of polyethylene oxide (PEO) is too low, the network density will be too high, restricting chain segment movement; while when the number-average molecular weight of PEO is too high, the spacing between crosslinking points may be too large, resulting in insignificant mechanical reinforcement. Preferably, the number-average molecular weight of PEO is within the above range, which helps to ensure sufficient mobility of polymer chains to maintain ion conduction, while also enabling the formation of an effective crosslinking network. Preferably, the number-average molecular weight of PEO is 1000 to 6000 g / mol; more preferably, the number-average molecular weight of PEO is 2000 to 4000 g / mol.

[0034] In some embodiments of this application, the number average molecular weight of polyethylene oxide is 400 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 2000 g / mol, 3000 g / mol, 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol, or 10000 g / mol, or of course, it can be any value between any two of the above.

[0035] In some embodiments of this application, the lithium salt is selected from any one or more of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPF6), and lithium perchlorate (LiClO4).

[0036] Preferring the above-mentioned lithium salts helps to make them compatible with D. 4h The synergistic effect of the coordination crosslinking network formed by the symmetrical binuclear metal carboxylic acid complex and the nitrogen-terminated polyether polymer enhances the dissociation ability and electrochemical window stability of lithium ions. Among them, LiFSI and LiTFSI have good dissociation degree and compatibility with polyethylene oxide, which can effectively suppress interfacial side reactions and promote rapid lithium ion transport, while LiPF6 and LiClO4 maintain good ionic conductivity and film-forming properties over a wide voltage range. The combined use of multiple lithium salts further optimizes the ion transference number and interfacial compatibility of the electrolyte system.

[0037] In some embodiments of this application, the molar ratio of lithium ions in the lithium salt to ether radical groups in the polyethylene oxide is 1:8 to 1:20.

[0038] The preferred molar ratio of lithium ions in the lithium salt to ether oxygen groups in the polyethylene oxide is within the above range, which helps to effectively optimize the solvation environment of lithium ions in the polymer matrix. This reduces the problem of ion transport path disruption caused by excessively low lithium ion concentration, and also reduces the risk of ion pair aggregation and local migration hindrance caused by excessively high concentration. Preferably, the molar ratio of lithium ions in the lithium salt to ether oxygen groups in the polyethylene oxide is 1:12 to 1:16.

[0039] In some embodiments of this application, the molar ratio of lithium ions in the lithium salt to ether radical groups in the polyethylene oxide is 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, or of course, it can be any two of the above values.

[0040] In some embodiments of this application, the mass percentage of the above-mentioned metal paddle wheel complex in the gel polymer electrolyte is 1% to 30%.

[0041] The content of the metal propeller complex in the gel polymer electrolyte determines the crosslinking density, which is a key parameter for controlling the balance between mechanical properties and ion conduction properties. Lower propeller content results in larger crosslinking point spacing and higher degrees of freedom for polymer chain movement, which is beneficial for ion conduction, but the improvement in mechanical strength is limited. Higher propeller content reduces the crosslinking point spacing, creating stronger constraints on chain segment movement, significantly improving mechanical strength, but limiting ion conduction. This application provides mechanical support through the rigid geometric constraints of the propeller rather than a dense covalent network, resulting in a lower degree of restriction on ion conduction at the same crosslinking density compared to traditional covalent crosslinking systems. Therefore, the above-mentioned mass percentage range is preferred, which helps to provide a significant mechanical enhancement effect to the crosslinking network while keeping the restriction on ion conduction within an acceptable range. More preferably, the mass percentage of the metal propeller complex in the gel polymer electrolyte is 5%~20%, and even more preferably, the mass percentage of the metal propeller complex in the gel polymer electrolyte is 8%~15%.

[0042] In some embodiments of this application, the mass percentage of the metal paddle wheel complex in the gel polymer electrolyte is 1%, 3%, 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, or 30%, or it can be any two of the above values.

[0043] In some embodiments of this application, the plasticizer is selected from any one or more of ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, ionic liquids and polyethers; and / or, the content of the plasticizer is 5% to 30% of the total mass of the gel polymer electrolyte.

[0044] The preferred types of plasticizers exhibit good compatibility with the coordination crosslinking network formed by the metal propeller complex and the nitrogen-terminated polyether polymer, which helps improve the ionic conductivity of the gel electrolyte. When ionic liquids or polyether plasticizers are used, the electrochemical window stability and interfacial wettability can be further enhanced, thereby improving battery cycle safety and rate performance. Preferably, the plasticizer content is within the above range, which helps to effectively regulate the swelling behavior and local free volume of the electrolyte system, promoting the rapid migration of lithium ions between polymer segments, thereby improving ionic conductivity. More preferably, the plasticizer content is 10% to 25% of the total mass of the gel polymer electrolyte.

[0045] In some embodiments of this application, the content of plasticizer is 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, or 30% of the total mass of the gel polymer electrolyte, or it can be any two of the above values.

[0046] In some embodiments of this application, the thickness of the gel polymer electrolyte layer is 10 to 100 micrometers.

[0047] The gel polymer electrolyte layer is located between the positive and negative electrodes, serving both ion conduction and isolating the electrodes to prevent short circuits. Preferably, the thickness of the gel polymer electrolyte layer is within the above-mentioned range, which helps improve the mechanical flexibility and structural stability of the electrolyte layer, effectively supporting the positive and negative electrode sheets and reducing the risk of breakage or interface delamination during assembly or cycling. It also maintains the continuity and low tortuosity of the ion transport channels, promoting efficient migration of lithium ions in the plasticizer solvation environment. More preferably, the thickness of the gel polymer electrolyte layer is 20-50 micrometers.

[0048] In some embodiments of this application, the thickness of the gel polymer electrolyte layer is 10 micrometers, 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, or 100 micrometers, or of course, it can be between any two of the above values.

[0049] In another typical embodiment of this application, a battery device is provided, which includes the aforementioned battery cell, and the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

[0050] The battery device of this application uses a battery cell containing a gel polymer electrolyte layer with metal propeller complex as molecular-level cross-linking nodes. This electrolyte layer maintains good mechanical strength and dimensional stability while maintaining high lithium-ion conductivity, effectively improving the cycle stability and safety of the battery under high-rate charge and discharge and wide temperature range conditions.

[0051] In yet another typical embodiment of this application, an electrical device is provided, which includes the aforementioned battery device for providing electrical energy.

[0052] The power supply unit of this application uses a battery cell containing a cross-linked gel polymer electrolyte with a metal propeller complex as the power supply unit. Since the electrolyte system has solution processability, excellent adhesion to the electrode interface and a non-brittle structure without a crystalline framework, the power supply unit does not require an additional wetting process during assembly, which reduces the manufacturing complexity and enhances the structural reliability of the system under conditions such as vibration and impact.

[0053] In yet another typical embodiment of this application, an energy storage device is provided, which includes the aforementioned battery device for storing electrical energy.

[0054] The energy storage device of this application uses a gel polymer electrolyte containing a metal propeller complex, a nitrogen-terminated polyether polymer, a lithium salt, and a plasticizer as its core component, which significantly improves the safety and cycle life of the energy storage device in large-scale energy storage scenarios.

[0055] Furthermore, the gel polymer electrolyte layer of this application not only significantly improves the electrochemical performance of lithium-ion batteries under high-rate and low-temperature environments, but is also more suitable for the needs of long-term energy storage systems. This gel polymer electrolyte layer helps improve the long-cycle stability and safety of lithium-ion batteries in large-scale energy storage scenarios, and can support the operation of large-scale energy storage power stations at the 4-hour (4h) and 8-hour (8h) levels, meeting the stringent requirements of high-capacity batteries for application scenarios such as grid peak shaving and smooth output of renewable energy.

[0056] The beneficial effects of this application will be explained below with reference to specific embodiments and comparative examples.

[0057] The raw materials are as follows:

[0058] The functionalized monocarboxylic acid ligand (ether oxygen chain number n=3) has the chemical name methoxytriethylene glycol acetic acid, molecular formula CH3O(CH2CH2O)3CH2COOH, molecular weight 222.24 g / mol, and purity not less than 99%. Before use, it should be dried in a vacuum drying oven at 60℃ for 12 h to ensure that the moisture content is less than 50 ppm. It can be purchased from commercial reagent suppliers or prepared by existing etherification / carboxymethylation methods.

[0059] The functionalized monocarboxylic acid ligand (ether oxygen chain number n=2) has the chemical name 2-[2-(2-methoxyethoxy)ethoxy]acetic acid, molecular formula CH3O(CH2CH2O)2CH2COOH, molecular weight 178.18 g / mol, and purity not less than 98%. Before use, it should be dried in a vacuum drying oven at 60℃ for 12 h to ensure that the moisture content is less than 50 ppm. It can be purchased from commercial reagent suppliers or prepared by existing methods.

[0060] The functionalized monocarboxylic acid ligand (ether oxygen chain number n=1) has the chemical name 2-(2-methoxyethoxy)acetic acid, molecular formula CH3O(CH2CH2O)CH2COOH, molecular weight 134.13 g / mol, and purity not less than 98%. Before use, it should be dried in a vacuum drying oven at 60℃ for 12 h to ensure that the moisture content is less than 50 ppm. It can be purchased from commercial reagent suppliers or prepared by existing methods.

[0061] Polyethylene glycol diacrylate (PEGDA, number average molecular weight approximately 700 g / mol) and photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (Irgacure 2959);

[0062] Zinc acetate dihydrate (Zn(CH3COO)2·2H2O), analytical grade, purity not less than 99.5%, is used to synthesize zinc-based propeller complexes;

[0063] Copper acetate monohydrate (Cu(CH3COO)2·H2O), analytical grade, with a purity of not less than 99%, is used to synthesize copper-based propeller complexes;

[0064] Pyridine-terminated polyethylene oxide: number average molecular weight approximately 3000 g / mol, nitrogen-terminated functionalization degree approximately 92 mol%, dried in a vacuum drying oven at 60 ℃ for 24 h before use, with moisture content controlled below 30 ppm; pyridine-terminated polyethylene oxide can be prepared from hydroxyl-terminated polyethylene oxide via pyridine group terminalization reaction, or obtained from commercial custom synthesis channels. The sample used in this example is designated as PEO-Py-3000;

[0065] Methoxylated end-capped polyethylene oxide: number average molecular weight approximately 3000 g / mol. Before use, it should be dried in a vacuum drying oven at 60 °C for 24 h to control the moisture content to below 30 ppm. The sample used in this example is MPEG-3000, which can be purchased from commercial polyether reagent suppliers.

[0066] Anhydrous acetic acid (glacial acetic acid, analytical grade, purity not less than 99.5%).

[0067] Terephthalic acid (analytical grade, purity not less than 99%)

[0068] Lithium bisfluorosulfonyl imide (LiFSI): Battery grade, purity not less than 99.9%, moisture content less than 10 ppm;

[0069] Ethylene carbonate (EC) and dimethyl carbonate (DMC) are both battery-grade reagents with a moisture content of less than 20 ppm. They are mixed at a volume ratio of 1:1 to prepare a carbonate plasticizer mixture for later use.

[0070] Regarding the battery cell materials: the positive electrode uses carbon-coated lithium iron phosphate active material with a D50 particle size of approximately 1.5 μm; the negative electrode uses artificial graphite active material with a D50 particle size of approximately 15 μm; the conductive agent is Super P with a specific surface area of ​​approximately 62 m². 2 / g; the positive electrode uses PVDF as a binder (weight average molecular weight of about 300,000 g / mol), and the negative electrode uses a CMC / SBR composite system as a binder; the current collectors are 15μm thick aluminum foil (positive electrode) and 8μm thick copper foil (negative electrode); the aluminum-plastic composite film is used for soft pack packaging, and all the above materials are battery grade.

[0071] Example 1

[0072] Reference Figure 1 The process flow diagram shown below illustrates the preparation of the gel polymer electrolyte membrane. The following preparation steps are performed:

[0073] Synthesis of zinc-based propeller complexes:

[0074] At room temperature, functionalized monocarboxylic acid ligands and zinc acetate dihydrate were dissolved in anhydrous methanol at a molar ratio of approximately 2:1 to prepare a mixed solution with a zinc salt concentration of approximately 0.1 mol / L. Triethylamine (at a molar ratio of approximately 1:1 with the functionalized monocarboxylic acid ligands) was added to neutralize the carboxylic acid and promote carboxylate formation. The reaction was carried out at 25 °C for 12 h under magnetic stirring. After the reaction was completed, the product was concentrated by rotary evaporation, and an appropriate amount of diethyl ether was added to precipitate the product. The product was filtered, washed with a small amount of anhydrous methanol, and dried in a vacuum drying oven at 60 °C for 24 h to obtain a white powdery product, namely the zinc-based propeller complex, which has D 4h A symmetrical binuclear metal carboxylic acid complex with the general chemical formula M2(O2CR)4, wherein M is zinc, -OC(O)R is a bridged carboxylic acid ligand, and R is CH3O(CH2CH2O)3CH2-, with a yield of approximately 80%.

[0075] Preparation of gel polymer electrolyte membrane:

[0076] In an argon glove box with moisture and oxygen content below 0.5 ppm, using a mixed solvent of N-methylpyrrolidone and tetrahydrofuran at a volume ratio of 1:3 as the dispersion medium, 10 wt% of a zinc-based paddle wheel complex and pyridine-terminated polyethylene oxide (based on the mass of the gel polymer electrolyte) were first added to the solvent. The mixture was magnetically stirred in a 35°C water bath for 2 hours until a homogeneous and transparent solution was obtained. LiFSI was then added to achieve a molar ratio of lithium ions in the lithium salt to ether groups in the pyridine-terminated polyethylene oxide of 1:14. Stirring continued for 1 hour until the lithium salt was completely dissolved. Finally, 20 wt% of an EC / DMC mixed plasticizer (EC to DMC mass ratio of 1:1) was added, and the mixture was stirred for 30 minutes until homogeneous, yielding the precursor solution. The precursor solution was coated onto a polytetrafluoroethylene plate with a wet film thickness of approximately 400 μm by a scraping method. After standing in a glove box at 25°C for 12 hours to evaporate most of the solvent, it was transferred to a vacuum drying oven at 45°C for another 12 hours to obtain a gel polymer electrolyte layer film.

[0077] Cell fabrication and assembly:

[0078] Electrochemical performance was verified using 3 to 5 Ah lithium iron phosphate / artificial graphite stacked small pouch cells.

[0079] The positive electrode uses carbon-coated lithium iron phosphate material, with an active material content of 93 wt%, a conductive agent content of 4 wt% Super P, and a binder content of 3 wt%. A positive electrode slurry (solid content of 55 wt%) is prepared using N-methylpyrrolidone as a solvent, coated onto a 15-micron thick aluminum foil current collector, and then dried and rolled to achieve an areal density of approximately 20 mg / cm². 2 The positive electrode is made of artificial graphite material, with an active material content of 95 wt% and a binder CMC / SBR composite system content of 5 wt%. A negative electrode slurry (solid content of 48 wt%) is prepared using deionized water as a solvent, coated onto an 8-micron thick copper foil current collector, and then dried and rolled to achieve an areal density of approximately 10 mg / cm². 2 The negative electrode is used. Battery assembly is carried out in an argon glove box. The gel polymer electrolyte membrane is cut to the size to match the electrode and placed between the positive and negative electrodes. The electrodes are stacked in the order of positive electrode / gel polymer electrolyte membrane / negative electrode. A pressure of 0.3 MPa is applied and hot-pressed at 60°C for 5 minutes to ensure good interfacial contact between the layers. The stacked cells are placed in an aluminum-plastic composite film shell, vacuum sealed, and then left to stand at 25°C for 24 hours to complete the initial wetting. Subsequently, formation and aging are completed to finally obtain the battery cell. Formation: The cells are charged at 0.05C at 25°C to 3.65 V with constant current, then charged at constant voltage until the current drops to 0.01C cutoff. After standing for 30 minutes, the cells are discharged at 0.05C with constant current to 2.5 V. This cycle is repeated 3 times. The cells after formation are used for subsequent performance testing.

[0080] Example 2

[0081] The difference from Example 1 is that the zinc-based propeller complex has a mass percentage of 5% in the gel polymer electrolyte to obtain a gel polymer electrolyte film, and finally obtain a battery cell.

[0082] Example 3

[0083] The difference from Example 1 is that the zinc-based propeller complex has a mass percentage of 8% in the gel polymer electrolyte to obtain a gel polymer electrolyte film, and finally obtain a battery cell.

[0084] Example 4

[0085] The difference from Example 1 is that the zinc-based propeller complex has a mass percentage of 15% in the gel polymer electrolyte to obtain a gel polymer electrolyte film, and finally obtain a battery cell.

[0086] Example 5

[0087] The difference from Example 1 is that the zinc-based propeller complex has a mass percentage of 20% in the gel polymer electrolyte to obtain a gel polymer electrolyte layer film, and finally obtain a battery cell.

[0088] Example 6

[0089] The difference from Example 1 is that the functionalized monocarboxylic acid ligand (ether oxygen chain number n=2) is 2-[2-(2-methoxyethoxy)ethoxy]acetic acid, with the molecular formula CH3O(CH2CH2O)2CH2COOH. Before use, it is dried in a vacuum drying oven at 60°C for 12 h to ensure a moisture content below 50 ppm. A zinc-based paddlewheel complex is obtained from this ligand, which has D... 4h A symmetrical binuclear metal carboxylic acid complex with the general chemical formula M2(O2CR)4, wherein M is zinc, -O(O)CR is a bridged carboxylic acid ligand, and R is CH3O(CH2CH2O)2CH2-; the remaining steps are the same as in Example 1, and finally a battery cell is obtained.

[0090] Example 7

[0091] The difference from Example 1 is that LiFSI is added to make the molar ratio of lithium ions in lithium salt to ether oxygen groups in polyethylene oxide 1:12, so as to obtain a gel polymer electrolyte layer film and finally obtain a battery cell.

[0092] Example 8

[0093] The difference from Example 1 is that the nitrogen-containing heterocyclic polyethylene oxide is an imidazole-terminated polyethylene oxide, which yields a gel polymer electrolyte layer membrane and ultimately a battery cell.

[0094] Example 9

[0095] The difference from Example 1 is that the functionalized monocarboxylic acid ligand (ether oxygen chain number n=1) is 2-(2-methoxyethoxy)acetic acid, with the molecular formula CH3O(CH2CH2O)CH2COOH; from this ligand, a zinc-based propeller complex is obtained, which has D 4h A symmetrical binuclear metal carboxylic acid complex with the general chemical formula M2(O2CR)4, wherein M is zinc, -O(O)CR is a bridged carboxylic acid ligand, and R is CH3O(CH2CH2O)CH2-; the remaining steps are the same as in Example 1, and the battery cell is finally obtained.

[0096] Example 10

[0097] The difference from Example 1 is that LiFSI is added to make the molar ratio of lithium ions in the lithium salt to ether oxygen groups in the pyridine-terminated polyethylene oxide 1:16, thereby obtaining a gel polymer electrolyte layer film and finally obtaining a battery cell.

[0098] Example 11

[0099] The difference from Example 1 is that LiFSI is added to make the molar ratio of lithium ions in the lithium salt to ether oxygen groups in pyridine-terminated polyethylene oxide 1:20, thereby obtaining a gel polymer electrolyte layer film and finally obtaining a battery cell.

[0100] Example 12

[0101] The difference from Example 1 is that LiFSI is added to make the molar ratio of lithium ions in the lithium salt to ether oxygen groups in pyridine-terminated polyethylene oxide 1:8, thereby obtaining a gel polymer electrolyte layer film and finally obtaining a battery cell.

[0102] Example 13

[0103] The difference from Example 1 is that 10 wt% of EC / DMC mixed plasticizer (EC to DMC mass ratio of 1:1) based on the total mass of electrolyte is added to obtain a gel polymer electrolyte layer film, and finally obtain the battery cell.

[0104] Example 14

[0105] The difference from Example 1 is that 8 wt% of EC / DMC mixed plasticizer (EC to DMC mass ratio of 1:1) based on the total mass of electrolyte is added to obtain a gel polymer electrolyte layer film, and finally obtain the battery cell.

[0106] Example 15

[0107] The difference from Example 1 is that the metal in the metal propeller complex is copper. Synthesis of the copper-based propeller complex: At room temperature, a functionalized monocarboxylic acid ligand (methoxytriethylene glycol acetic acid, CH3O(CH2CH2O)3CH2COOH) and copper acetate monohydrate were dissolved in anhydrous methanol at a molar ratio of approximately 2:1 to prepare a mixed solution with a copper salt concentration of approximately 0.1 mol / L. Triethylamine (with a molar ratio of approximately 1:1 to the functionalized monocarboxylic acid ligand) was added to neutralize the carboxylic acid and promote carboxylate formation. The reaction was carried out at 25°C for 12 h under magnetic stirring. After the reaction was completed, the product was concentrated by rotary evaporation, and an appropriate amount of diethyl ether was added to precipitate the product. After filtration and washing with a small amount of anhydrous methanol, the product was dried in a vacuum drying oven at 60°C for 24 h to obtain a blue-green powdery product, i.e., the copper-based propeller complex, which has a D... 4h A symmetrical binuclear metal carboxylic acid complex with the general chemical formula M2(O2CR)4, wherein M is copper, -O(O)CR is a bridged carboxylic acid ligand, and R is CH3O(CH2CH2O)3CH2-, with a yield of approximately 82%. The remaining steps, including film formation, cell preparation and assembly, and formation, are the same as in Example 1. The copper-based propeller complex comprises 10 wt% of the gel polymer electrolyte, the molar ratio of lithium ions in the lithium salt to the ether oxygen groups in the pyridine-terminated polyethylene oxide is 1:14, and the plasticizer is 20 wt% of an EC / DMC mixed plasticizer (EC to DMC mass ratio of 1:1) based on the total electrolyte mass. The final battery cell is obtained.

[0108] Comparative Example 1

[0109] The difference from Example 1 is that no zinc-based propeller complex was added during the preparation of the gel polymer electrolyte, and pyridine-terminated polyethylene oxide was replaced with methoxy-terminated polyethylene oxide, ultimately yielding the battery cell.

[0110] Comparative Example 2

[0111] The difference from Example 1 is that, in the process of preparing the gel polymer electrolyte, the zinc-based propeller complex was replaced with polyethylene glycol diacrylate (PEGDA) and the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone. At the same time, in the process of preparing the gel polymer electrolyte, the pyridine-terminated polyethylene oxide was replaced with methoxy-terminated polyethylene oxide, and finally the battery cell was obtained.

[0112] Comparative Example 3

[0113] The difference from Example 1 is that, in the process of preparing the gel polymer electrolyte, methoxy-terminated polyethylene oxide was used instead of pyridine-terminated polyethylene oxide, and the final battery cell was obtained.

[0114] Comparative Example 4

[0115] The difference from Example 1 is that anhydrous acetic acid was used to replace the functionalized monocarboxylic acid ligand CH3O(CH2CH2O)3CH2COOH (i.e., methoxytriethylene glycol acetic acid) in Example 1, and the battery cell was finally obtained.

[0116] Comparative Example 5

[0117] The difference from Example 1 is that terephthalic acid was used to replace the functionalized monocarboxylic acid ligand CH3O(CH2CH2O)3CH2COOH in Example 1, and the mixture was reacted in N,N-dimethylformamide at 100°C for 24 hours with terephthalic acid and zinc acetate dihydrate in an equimolar ratio. The resulting solid was filtered, dried and used for subsequent preparations to finally obtain the battery cell.

[0118] Performance testing:

[0119] Regarding membrane-level performance testing:

[0120] Ionic conductivity (T1): Measured by AC impedance spectroscopy on a stainless steel blocked electrode symmetric cell (SS / GPE / SS), with a test frequency range of 100 kHz to 0.01 Hz, AC amplitude of 10 mV, and test temperatures of 25℃ and 45℃ (the same set of samples was heated to 45℃ and then equilibrated for 1 h before repeated testing). Ionic conductivity σ was calculated using the formula σ=L / (R×S), where L is the actual average film thickness of each sample, R is the volume resistance corresponding to the intersection of the high-frequency end of the Nyquist plot with the real axis, and S is the effective area of ​​the stainless steel electrode (2.0 cm²). Three parallel samples were prepared for each formulation, and the average value was taken.

[0121] Tensile properties (T2): Determined on a universal tensile testing machine. The specimen specifications refer to GB / T 1040.3-2006, with a gauge length of 50 mm, a tensile rate of 5 mm / min, and a test temperature of 25℃. Tensile strength (MPa), Young's modulus (MPa), and elongation at break (%) are extracted simultaneously from the same stress-strain curve. The average value of 5 parallel samples in each group is taken.

[0122] Thermal dimensional stability (T3) was characterized by thermal shrinkage rate: each sample was cut into a standard square of 50 mm × 50 mm, the initial area A0 was recorded, and the sample was placed in a 100℃ forced-air oven for 1 hour. After being taken out and cooled to 25℃, the remaining area A1 was measured. The thermal shrinkage rate was calculated as (A0-A1) / A0×100%, and the average value of 3 parallel samples in each group was taken.

[0123] Meanwhile, a simplified bending evaluation was performed on each electrolyte membrane: the membrane sample was manually bent 180 degrees along the same straight line and held for 5 seconds, and it was observed whether any visible cracks or breaks appeared, which was used to help evaluate the flexibility and integrity of the membrane.

[0124] Electrochemical stability window (T4): determined by linear sweep voltammetry in SS / GPE / Li coin cells, from the open-circuit voltage forward to 6.0 V (vs. Li / Li). + The scan rate was 0.5 mV / s, and the starting potential at which the current density increased sharply was taken as the oxidation decomposition potential. The test temperature was 25℃.

[0125] Regarding cell-level performance testing:

[0126] Full cell interface impedance after formation (T5): After the cell formation is completed, the cell is adjusted to 50% SOC by charging and discharging at 0.1C. After standing for 2 hours, AC impedance spectrum test is performed (frequency range 100 kHz to 0.01 Hz, amplitude 10 mV). The total interface impedance is extracted by equivalent circuit fitting and normalized to Ω·cm² according to the effective electrode area. The test temperature is 25 degrees Celsius.

[0127] First-week coulomb efficiency (T6): Calculated from the first charge and discharge data during the formation stage. CE1 is equal to the first discharge capacity divided by the first charge capacity and then multiplied by 100%. The charge and discharge rate is 0.05C and the test temperature is 25 degrees Celsius.

[0128] 25°C Cyclic Capacity Retention Rate (T7): Constant current charge-discharge cycles were performed at 25°C with a 1C / 1C rate. The charging cutoff condition was a constant voltage of 3.65 V until the current dropped to 0.05C, and the discharge cutoff voltage was 2.5 V. The discharge capacity was recorded for the 100th and 200th cycles, and the capacity retention rate (%) was calculated based on the first discharge capacity under these test conditions.

[0129] 45°C High Temperature Cycling Capacity Retention Rate (T8): Using the same charge and discharge regime as T7, the test temperature was raised to 45°C, and the capacity retention rate was recorded after the 100th cycle.

[0130] Rate performance (T9): Measured at 25°C: A fixed charge rate of 0.5C (constant current to 3.65 V, constant voltage to 0.05C cutoff) was applied, followed by discharge rates of 0.2C, 0.5C, 1C, and 2C. Each rate was cycled 5 times. The capacity retention rate (%) under 1C and 2C conditions was calculated using the discharge capacity at 0.2C as the baseline (100%). All cell-level tests were conducted using a battery testing system. At least two parallel cells were assembled for each formulation, and the average value was reported.

[0131] The test results of each embodiment and comparative example are listed in Tables 1 to 3.

[0132] Table 1

[0133]

[0134]

[0135] Table 2

[0136]

[0137] Table 3

[0138]

[0139] The specific analysis of the above data is as follows:

[0140] The following analysis, based on the performance test prediction data in Tables 1 to 3, systematically examines the experimental results of each embodiment and comparative example of the present invention. The discussion revolves around the verification of five core technical features, the optimization principles of propeller content, and the influence of key parameters.

[0141] The necessity of molecular-level crosslinking nodes in the metal propeller can be directly quantified by comparing the data from Example 1 and Comparative Example 1. Comparative Example 1 (a non-crosslinked system without the metal propeller complex) has a room-temperature ionic conductivity of 1.25 mS / cm, slightly higher than the 1.05 mS / cm of Example 1, indicating that the unconstrained polymer segments have higher degrees of freedom of movement. However, in terms of mechanical properties, Comparative Example 1 has a tensile strength of only 2.2 MPa, a Young's modulus of only 11 MPa, and a thermal shrinkage rate as high as 22.0%, representing decreases of 74% and 76% respectively compared to Example 1 (8.5 MPa, 46 MPa, 3.8%), while the thermal shrinkage rate increases by approximately 4.8 times. Significant deformation of the membrane occurred during bending tests, indicating that the gel polymer electrolyte membrane without a crosslinked network has almost no effective structural support and dimensional stability. Cell-level testing further amplified this gap: the interfacial impedance after formation in Comparative Example 1 reached as high as 68 Ω·cm² (compared to 25 Ω·cm² in Example 1), and the capacity retention rate after 200 cycles at 25°C was only 73.8% (compared to 88.5% in Example 1), while the capacity retention rate after 100 cycles at 45°C dropped to 69.5% (compared to 86.5% in Example 1). This result indicates that a gel electrolyte membrane lacking mechanical support cannot maintain stable electrode interface contact during battery cycling. As the volumetric deformation of the electrode gradually accumulates due to charge and discharge, interface failure intensifies, ultimately leading to rapid capacity decay. These data fully demonstrate the indispensability of the molecular-level crosslinking nodes of the metal propeller for simultaneously satisfying the mechanical integrity of the electrolyte and long-term interfacial stability.

[0142] The superiority of coordination crosslinking over traditional covalent crosslinking is directly demonstrated by the comparison between Example 1 and Comparative Example 2. Comparative Example 2 (PEGDA covalent crosslinking system) exhibited a tensile strength of 14.5 MPa, a Young's modulus as high as 92 MPa, and a thermal shrinkage rate of 5.2%, all significantly better than Comparative Example 1, proving that covalent crosslinking can indeed effectively establish a mechanically constrained network. However, the room temperature ionic conductivity of Comparative Example 2 was only 0.62 mS / cm, a decrease of 41% compared to Example 1; the capacity retention rate at 2C rate was only 64.8%, a decrease of 17.7 percentage points compared to Example 1 (82.5%); and the capacity retention rate after 200 cycles at 25 degrees Celsius was 80.2%, lower than 88.5% of Example 1. Furthermore, the elongation at break of Comparative Example 2 was only 55% (182% in Example 1), and significant cracking occurred during bending tests, reflecting the severe constraint of the covalent crosslinking network on the flexibility of polymer segments. This typical negative correlation of "improved mechanical properties but lost transport performance" is precisely the inherent defect of traditional covalent crosslinking strategies. In contrast, Example 1 provides local spatial constraints through the regular geometry of the metal paddle wheel complex, rather than relying on a dense covalent network, allowing polymer segments to maintain greater mobility between crosslinking points. This results in the simultaneous maintenance of a room temperature ionic conductivity of 1.05 mS / cm and a 2C rate retention rate of 82.5% at mechanical support levels of 8.5 MPa tensile strength and 46 MPa young modulus, achieving synergistic optimization of the two core properties.

[0143] The necessity of coordination bonds between nitrogen-containing end groups and the axial sites of the propeller wheel was directly verified by the data from Comparative Example 3. Comparative Example 3 (where methoxy-terminated PEO replaced pyridine-terminated PEO, and the propeller wheel existed as a physical blend) exhibited a tensile strength of 2.8 MPa, a Young's modulus of 14 MPa, a thermal shrinkage rate of 18.5%, an interfacial impedance of 72 Ω·cm² after formation, and a capacity retention of only 72.5% after 200 cycles at 25°C. These mechanical and cell-level performance indicators were similar to those of Comparative Example 1 (the uncrosslinked system), but significantly lower than those of Example 1. This result indicates that when the PEO end groups do not contain coordinating nitrogen atoms, although the metal propeller wheel complex physically exists in the system, it cannot form effective axial coordination bonds with the polymer chain ends, degenerating into a simple physical blend, and its contribution to the mechanical network is negligible. It is worth noting that the room temperature ionic conductivity of Comparative Example 3 was 1.15 mS / cm, which is close to that of Comparative Example 1. This indicates that the physically blended impeller did not significantly hinder ion conduction, but it also could not provide the spatial topological guiding effect achieved through coordination crosslinking in Example 1. The high similarity between Comparative Example 3 and Comparative Example 1 in terms of mechanics and stability proves that "the formation of coordination bonds between the nitrogen-containing heterocyclic end group and the axial site of the impeller" is a necessary condition for the realization of the functionalized crosslinked network in the system of this invention, rather than an optional structural detail.

[0144] The substantial contribution of the oligoether oxygen-functionalized bridging ligand was quantified by comparing Comparative Example 4 (bridging ligand replaced with acetic acid, n=0) with Example 1. The room temperature ionic conductivity of Comparative Example 4 was 0.78 mS / cm, a 26% decrease compared to Example 1; the interfacial impedance after formation was 44 Ω·cm² (25 Ω·cm² in Example 1); the 2C rate retention was 74.2% (82.5% in Example 1); and the first-cycle coulombic efficiency was 90.8% (92.5% in Example 1). Mechanically, Comparative Example 4 exhibited a tensile strength of 7.2 MPa and a Young's modulus of 40 MPa, close to but slightly lower than that of Example 1, indicating that the coordination crosslinking between the nitrogen-containing end groups and the propeller still existed in Comparative Example 4, and the crosslinked backbone was preserved, but the overall performance was inferior to that of Example 1. The source of this performance difference can be analyzed from two aspects: the absence of the ether-oxygen side chain reduces the solubility and dispersibility of the metal propeller complex in the polymer matrix and plasticizer, resulting in poor film uniformity and a decrease in interfacial contact quality, manifested in higher interfacial impedance and slightly lower first-turn coulombic efficiency; simultaneously, it is speculated that the absence of the ether-oxygen side chain worsens the local lithium-ion solvation environment around the propeller node, increasing the ion migration activation energy, directly leading to a significant decrease in ionic conductivity and rate performance. The results of Comparative Example 4 demonstrate that the contribution of the oligomeric ether-oxygen segment in the functionalized monocarboxylic acid ligand to the regulation of the local ion transport environment has a substantial impact on the overall performance of the system; removing this functional structural element significantly impairs ion conduction and interfacial stability while maintaining the crosslinked backbone.

[0145] The inherent advantages of discrete molecular states relative to extended coordination frameworks are most clearly demonstrated by the data from Comparative Example 5. Comparative Example 5 exhibits the worst results in almost all performance dimensions: its room-temperature ionic conductivity is only 0.48 mS / cm, the lowest among all examples and comparative examples; its post-formation interfacial impedance is as high as 125 Ω·cm², five times that of Example 1; its first-cycle coulombic efficiency is only 84.8%, reflecting severe irreversible side reactions at the initial interface; its capacity retention after 200 cycles at 25°C is only 67.5%, and after 100 cycles at 45°C, it is only 61.8%; its electrochemical stability window is 4.3 V, lower than that of Example 1 (4.7 V). Film-forming performance evaluation shows that Comparative Example 5 exhibits "poor film-forming properties, uneven particle settling, and cracking upon bending," a stark contrast to Example 1, which is "uniform and transparent, self-supporting, and does not crack upon 180-degree bending." The above results indicate that after using dicarboxylic acid ligands to induce the formation of an extended coordination framework, a large number of framework particles settle in the solution, failing to form a uniform film; there is a significant interfacial discontinuity between the crystalline rigid particles and the polymer matrix, hindering lithium-ion transport at the phase interface; the brittle structure is prone to cracking under bending deformation, failing to form stable surface contact with the electrode surface, resulting in extremely high interfacial impedance and a sharp decline in cycle stability. The comprehensive degradation of Comparative Example 5 demonstrates from the opposite perspective that "discrete molecular states" are the key structural prerequisite for achieving excellent film formation, electrode interface compatibility, and long-term cycle stability, rather than a simple formal description.

[0146] The influence of the metal propeller compound content on the synergistic optimization window of mechanical and transmission performance was established using Examples 2 to 5 (propeller contents of 5 wt%, 8 wt%, 15 wt%, and 20 wt%, respectively) and Example 1 (10 wt%). Table 1 shows that as the propeller content increases from 5 wt% to 20 wt%, key indicators exhibit systematic changes: ionic conductivity monotonically decreases from 1.22 mS / cm (Example 2) to 0.75 mS / cm (Example 5); tensile strength monotonically increases from 5.2 MPa (Example 2) to 14.0 MPa (Example 5); Young's modulus increases from 26 MPa to 78 MPa; thermal shrinkage decreases from 9.5% to 1.8%; and interfacial impedance after formation decreases from 38 Ω·cm² to 18 Ω·cm². This trend reflects the continuous strengthening of structural support by increased crosslinking density, while simultaneously imposing gradual restrictions on chain segment movement. However, the 2C rate retention rate of Example 5 (20 wt%) decreased to 75.5%, significantly lower than that of Example 1 (82.5%), indicating that excessively high crosslinking density began to significantly suppress ion transport capability at high rates. Considering all indicators, Examples 3 (8 wt%) and 4 (15 wt%) showed good overall performance, with capacity retention rates of 87.8% and 89.5% respectively after 200 cycles at 25°C. Example 1 (10 wt%) achieved the best overall balance between mechanical support, ion conduction, long-cycle stability, and rate performance. These data collectively support the conclusion that "8% to 15% is a better range for the synergistic optimization of mechanical strength and ionic conductivity," and also indicate that the system can maintain reasonable performance within a wide range of 5% to 20%, demonstrating that the technical solution of this invention has a wide process tolerance window.

[0147] The effects of the number of ether oxygen chain segments in the bridging ligand, lithium salt concentration, and plasticizer content were verified by Examples 1, 6, and 9, Examples 7, 10 to 12, and Examples 13 and 14, respectively. Regarding the number of ether oxygen chain segments, the room temperature ionic conductivity of Examples 1 (n=3), 6 (n=2), and 9 (n=1) were 1.05, 0.98, and 0.88 mS / cm, respectively, all higher than the 0.78 mS / cm of Comparative Example 4 (n=0). The combination of high conductivity and stable cycle retention between n=2 and n=3 demonstrates the rationale for selecting n=2 to n=3. Regarding lithium salt concentration, Examples 7 (Li / O=1:12) and 10 (Li / O=1:16) exhibited room temperature ionic conductivity of 1.18 and 1.02 mS / cm, respectively, and capacity retention of 87.8% and 88.6% at 25°C for 200 weeks, respectively. Their overall performance was superior to Examples 11 (Li / O=1:20) and 12 (Li / O=1:8), indicating that 1:12 to 1:16 is a more preferred salt concentration window. Regarding plasticizer content, Example 13 (10 wt%) maintained a room temperature conductivity of 0.88 mS / cm and a capacity retention of 89.0% at 25°C for 200 weeks, while the 2C rate retention of Example 14 (8 wt%) decreased to 73.8%, indicating that a plasticizer content of 10 wt% to 25 wt% is more beneficial for balancing ion transport and cycling stability.

[0148] The flexibility of nitrogen-containing end-group types was verified in Example 8 (imidazolium-terminated PEO). The room-temperature ionic conductivity of Example 8 was 1.08 mS / cm, close to that of Example 1 (1.05 mS / cm); the tensile strength of 9.2 MPa and Young's modulus of 50 MPa were comparable to Example 1; the capacity retention rate after 200 cycles at 25°C was 88.0%, after 100 cycles at 45°C it was 86.2%, and the 2C rate retention rate was 81.5%. All these indicators were similar to those of Example 1, demonstrating that the imidazolium group also has effective coordination ability to the axial coordination sites of zinc, forming a fully functional coordination crosslinking network. The minor performance differences between Example 8 and Example 1 are presumably related to slight differences in the coordination strength and geometry of the pyridinium and imidazolium groups to zinc, but these differences have a minimal impact on the overall performance.

[0149] The flexibility of metal type was verified by Example 15 (copper-based propeller complex). Example 15 exhibited a room temperature ionic conductivity of 1.02 mS / cm, tensile strength of 8.8 MPa, Young's modulus of 48 MPa, capacity retention of 88.2% after 200 cycles at 25°C, and 2C rate retention of 82.0%. All these indicators were similar to those of Example 1, which used a zinc-based propeller complex. This demonstrates that both copper and zinc dinuclear carboxylic acid propeller complexes can form effective coordination crosslinking networks with nitrogen-terminated polyethers through axial sites, exerting a considerable synergistic effect in mechanical reinforcement and ion conduction.

[0150] Based on the data from all experimental groups, the gel polymer electrolyte system of this invention, with metal paddle wheel complexes as molecular-level crosslinking nodes, achieves systematic performance improvements in several key technical dimensions. Regarding the synergistic optimization of mechanical and transport properties, Example 1 maintains a room-temperature ionic conductivity of 1.05 mS / cm while also achieving a tensile strength of 8.5 MPa and a Young's modulus of 46 MPa. Compared to the uncrosslinked Comparative Example 1, it significantly improves mechanical properties while only incurring a conductivity loss of approximately 16%. Compared to the covalently crosslinked Comparative Example 2, it maintains similar mechanical support while exhibiting 69% higher conductivity and a 17.7 percentage point higher 2C rate retention rate. In terms of processability and interface compatibility, Example 1 can form a uniform, transparent, and bendable self-supporting film through a solution coating process. After formation, the interfacial impedance is only 25 Ω·cm², while the interfacial impedance of the extended framework control Comparative Example 5 is as high as 125 Ω·cm², a difference of 5 times. Regarding long-term cycling stability, Example 1 maintained 88.5% capacity retention after 200 cycles at 25°C and 86.5% after 100 cycles at 45°C, both significantly better than the comparative examples. The performance improvements reflected in these data cover the three core objectives of this invention: synergistic optimization of mechanical and ion conduction properties, superiority of discrete molecular states over crystalline extended frameworks, and superiority of coordination crosslinking over traditional covalent crosslinking. The verification results of the examples are highly consistent with the design goals of the technical solution.

[0151] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A battery cell, characterized in that, The device includes a positive electrode, a negative electrode, and a gel polymer electrolyte layer located between the positive electrode and the negative electrode. The gel polymer electrolyte layer includes a gel polymer electrolyte, which includes a metal propeller complex, a nitrogen-terminated polyether polymer, a lithium salt, and a plasticizer. The metal propeller complex comprises 1% to 30% by mass in the gel polymer electrolyte; the metal propeller complex has a D... 4h A symmetrical binuclear metal carboxylic acid complex, the general chemical formula of which is M2(O2CR)4, wherein M is zinc and / or copper, -O(O)CR is a bridged carboxylate ligand, and R comprises an oligoether oxygen segment; wherein -O(O)CR is CH3O(CH2CH2O). n CH2C(O)O-, where n is the number of repeating ether oxygen units, and n is any integer from 1 to 6; The end groups of the nitrogen-terminated polyether polymer are nitrogen-containing heterocyclic groups; Furthermore, the axial site of M in the binuclear metal carboxylic acid complex is connected to the nitrogen-containing heterocyclic group of the nitrogen-terminated polyether polymer via a coordinate bond; The nitrogen-terminated polyether polymer is a polyoxyethylene containing nitrogen-containing heterocyclic groups, wherein the nitrogen-containing heterocyclic groups are selected from any one of pyridyl, imidazolyl, and triazolyl.

2. The battery cell according to claim 1, characterized in that, The number-average molecular weight of the polyoxyethylene is from 400 g / mol to 10000 g / mol.

3. The battery cell according to claim 2, characterized in that, The lithium salt is selected from any one or more of lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, and lithium perchlorate.

4. The battery cell according to claim 2, characterized in that, The molar ratio of lithium ions in the lithium salt to ether groups in the polyethylene oxide is 1:8 to 1:

20.

5. The battery cell according to claim 1, characterized in that, The plasticizer is selected from any one or more of ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, ionic liquids and polyethers; and / or, the content of the plasticizer is 5% to 30% of the total mass of the gel polymer electrolyte.

6. The battery cell according to claim 1, characterized in that, The thickness of the gel polymer electrolyte layer is 10~100 micrometers.

7. A battery device, characterized in that, The battery device includes the battery cell according to any one of claims 1 to 6, and the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

8. An electrical device, characterized in that, The electrical device includes the battery device of claim 7, the battery device being used to provide electrical energy.

9. An energy storage device, characterized in that, The energy storage device includes the battery device of claim 7, the battery device being used to store electrical energy.

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