Quasi-solid-state alkali ion battery super-crosslinked polymer-based electrolyte and preparation method and application thereof

Abstract

The invention relates to and provides a quasi-solid-state alkali ion battery super-crosslinked polymer-based electrolyte. The electrolyte comprises 100 parts by weight of a super-crosslinked polymer and 50-200 parts by weight of an alkali ion battery electrolyte, wherein the alkali ion battery electrolyte is dispersed in the super-crosslinked polymer; the monomers of the super-crosslinked polymer are selected from benzene, methylbenzene, dimethylbenzene, chloromethyl benzene, biphenyl, 4, 4 '-dimethyl biphenyl and 4, 4'-dichloromethyl biphenyl; the average pore size of the super-crosslinked polymer is 1-10 nm, and the thickness of the super-crosslinked polymer is 100-300 [mu] m. The super-crosslinked polymer-based electrolyte for the quasi-solid alkali ion battery prepared by the invention has the advantages of wide use conditions, high mechanical strength, good cycle performance, stable electrochemical performance and the like.

Description

Technical Field

[0001] The present invention belongs to the field of battery materials, and particularly relates to a quasi-solid-state alkali-ion battery super-crosslinked polymer-based electrolyte, a preparation method thereof, and an application thereof. Background Art

[0002] The over-exploitation and utilization of non-renewable resources such as petroleum, coal, and natural gas will lead to their rapid depletion. Ultimately, it will affect the survival and development of humanity. The extensive use of these fossil energies will also exacerbate environmental pollution and damage the living environment of humanity. However, today with the rapid economic development, the demand for energy by humanity is getting higher and higher, and the utilization of these non-renewable resources is also increasing year by year. Therefore, in order to achieve the sustainable development of society, finding substitutes for these non-renewable resources has become a problem that humanity must solve at present. Currently, energy storage methods that have been developed by humanity include flywheel energy storage, compressed air energy storage, pumped-storage energy storage, supercapacitor energy storage, and battery energy storage, etc. Among them, battery energy storage mainly uses the redox reaction between the positive and negative electrode materials to achieve the mutual conversion of chemical energy and electrical energy. Due to its high conversion efficiency and the ability to better meet the applications under different environments and different size requirements, it has received extensive attention at present. Energy storage batteries mainly include nickel-metal hydride batteries, lead-acid batteries, flow batteries, and alkali metal ion batteries, etc. Among them, alkali metal ion batteries including lithium-ion batteries and sodium-ion batteries have shown obvious advantages among many energy storage batteries due to their high energy density, good cycling performance, no memory effect, and environmental friendliness, etc.

[0003] As a medium for ion transport between the positive and negative electrodes, the electrolyte plays an important role in the battery system. Currently, in alkali metal ion batteries, liquid electrolytes are mainly used. Non-aqueous liquid electrolytes are mainly composed of organic solvents and potassium salts. Although organic solvents have strong ion conductivity, they are volatile and flammable, resulting in safety hazards such as easy ignition and explosion during the use of the battery. Therefore, there is an urgent need to develop new solid electrolytes. An ideal solid electrolyte should have high room temperature ionic conductivity, a wide electrochemical stability window, excellent stability, and excellent mechanical properties. The core of a solid-state battery is a solid electrolyte. In recent years, the research on solid-state batteries has mainly focused on the development of solid electrolytes with excellent performance. Summary of the Invention

[0004] In view of this, the present invention aims to provide a quasi-solid-state alkali-ion battery super-crosslinked polymer-based electrolyte, a preparation method thereof, and an application thereof.

[0005] The first aspect of the present invention relates to providing a quasi-solid-state alkali-ion battery super-crosslinked polymer-based electrolyte, comprising 100 parts by weight of super-crosslinked polymer, and 50 to 200 parts by weight, preferably 50 to 150 parts by weight, more preferably 70 to 150 parts by weight, even more preferably 100 to 150 parts by weight of an alkali ion battery electrolyte; wherein, the alkali ion battery electrolyte is dispersed in a hypercrosslinked polymer; the monomers of the hypercrosslinked polymer are selected from benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl, and 4,4'-dichloromethylbiphenyl, preferably selected from benzene, toluene, xylene, biphenyl, and 4,4'-dimethylbiphenyl, more preferably selected from benzene and biphenyl; the average pore size of the hypercrosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, more preferably 2 to 5 nm, the thickness of the hypercrosslinked polymer is 100 - 300 μm, preferably 150 - 300 μm, more preferably 150 - 250 μm.

[0006] The second aspect of the present invention relates to providing a method for preparing a quasi-solid-state alkali ion battery hypercrosslinked polymer-based electrolyte of the present invention, comprising the following steps: i) subjecting an aromatic compound and a crosslinking agent to a crosslinking reaction in the presence of a catalyst to obtain a hypercrosslinked polymer; ii) shaping and drying the hypercrosslinked polymer to obtain a hypercrosslinked polymer-based film; iii) dispersing the alkali ion battery electrolyte into the hypercrosslinked polymer-based film by infiltration to obtain a quasi-solid-state alkali ion battery hypercrosslinked polymer-based electrolyte; wherein, the weight ratio of the hypercrosslinked polymer-based film to the alkali ion battery electrolyte dispersed in the film is 1:(0.5 - 2), preferably 1:(0.5 - 1.5), more preferably 1:(0.7 - 1.5), even more preferably 1:(1 - 1.5); the aromatic compound is selected from benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl, and 4,4'-dichloromethylbiphenyl, preferably selected from benzene, toluene, xylene, biphenyl, and 4,4'-dimethylbiphenyl, more preferably selected from benzene and biphenyl; the average pore size of the hypercrosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, more preferably 2 to 5 nm; the thickness of the hypercrosslinked polymer film is 100 - 300 μm, preferably 150 - 300 μm, more preferably 150 - 250 μm.

[0007] The third aspect of the present invention relates to providing the application of the quasi-solid-state alkali ion battery hypercrosslinked polymer-based electrolyte of the present invention in a secondary battery.

[0008] The beneficial effects of the present invention are as follows: The present invention provides a quasi-solid-state alkali ion battery ultra-crosslinked polymer-based electrolyte. This electrolyte combines the advantages of solid-state electrolytes and liquid electrolytes, improving the comprehensive performance. The raw materials of the quasi-solid-state alkali ion battery ultra-crosslinked polymer-based electrolyte prepared by the present invention are easily available and have low toxicity. Moreover, the preparation process of the present invention is simple, with low cost and easy to implement. The quasi-solid-state alkali ion battery ultra-crosslinked polymer-based electrolyte prepared by the present invention has the advantages of wide operating conditions, high mechanical strength, good cycling performance, and stable electrochemical performance. Description of the Drawings

[0009] Figure 1 Schematic diagram of the microscopic morphology of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 2 Graph of the specific surface area test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 3 Graph of the average pore size test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 4 Graph of the linear voltammetry scan test and cyclic voltammetry test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 5 Graph of the constant current charge and discharge test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 6 Schematic diagram of the microscopic morphology of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 7 Graph of the specific surface area test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 8 Graph of the average pore size test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 9 Graph of the linear voltammetry scan test and cyclic voltammetry test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 10 Graph of the constant current charge and discharge test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state sodium ion batteries; Figure 11 Schematic diagram of the microscopic morphology of the ultra-crosslinked polymer-based electrolyte membrane for quasi-solid-state potassium ion batteries; Figure 12 Graph of the constant current charge and discharge test results of the ultra-crosslinked polymer-based electrolyte for quasi-solid-state potassium ion batteries. Detailed Embodiments

[0010] In the following, the present invention will be described in more detail.

[0011] As used herein, the term "comprising" and its synonyms "including" and "containing" mean "including but not limited to", and are not intended to exclude, for example, other additives, components, integers or steps.

[0012] The "ranges" disclosed in this application are defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include the end values or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are understood to be contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed herein, and "0-5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0013] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0014] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0015] If there is no special instruction, all steps of this application can be carried out sequentially, randomly, or simultaneously. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out sequentially, or can include steps (b) and (a) carried out sequentially, or can include steps (a) and (b) carried out simultaneously. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b) and (c), or can include steps (a), (c) and (b), or can include steps (c), (a) and (b), etc.

[0016] If there is no special instruction, the meanings of the terms mentioned in this application are the same as those generally understood by those skilled in the art.

[0017] Unless otherwise specified, the operations mentioned in this application are carried out at room temperature and normal pressure.

[0018] Unless otherwise specified, the operations mentioned in this application can be implemented by means known to those skilled in the art.

[0019] Unless otherwise specified, the devices, apparatuses, instruments, parts, materials, medicaments, etc. mentioned in this application can be obtained by means known to those skilled in the art.

[0020] Unless otherwise specified, the indicators mentioned in this application, such as specific surface area, pore size, etc., can be measured by means known to those skilled in the art.

[0021] The term "quasi-solid state" mentioned in the present invention refers to a special physical state of the electrolyte, which is between the traditional liquid electrolyte and the all-solid-state electrolyte. Specifically, it means that the main body of the electrolyte is composed of solid materials (such as hypercrosslinked polymers), but may contain a small amount of liquid components (such as liquid electrolytes). These liquid components are "locked" in the three-dimensional network of the polymer and do not flow freely. The overall electrolyte macroscopically appears as a solid (non-fluid), but microscopically there may be a local liquid-like ion transport environment, combining the stability of the solid state and the high ionic conductivity of the liquid state. The quasi-solid state electrolyte of the present invention is easier to form a tight contact with the electrode compared to the all-solid-state electrolyte, reducing the interfacial impedance; compared to the liquid electrolyte, it avoids the risk of leakage and improves safety.

[0022] According to one aspect of the present invention, the present invention provides a quasi-solid state alkali ion battery hypercrosslinked polymer-based electrolyte, comprising 100 parts by weight of hypercrosslinked polymer and 50 - 200 parts by weight of alkali ion battery electrolyte. Among them, the alkali ion battery electrolyte is dispersed in the hypercrosslinked polymer.

[0023] Without being bound by any theory, the inventors unexpectedly found that the alkali ion battery electrolyte is adsorbed within the framework of the porous hypercrosslinked polymer (i.e., the solid electrolyte) through nanoscale pores. By utilizing intermolecular forces such as hydrogen bonds and dipole-dipole interactions, solvent molecules and anion groups are anchored on the pore channels inside the hypercrosslinked polymer material, thereby restricting their movement. This behavior not only reduces the erosion of the solvent on the electrode material, but also allows alkali metal ions in the solid electrolyte to migrate rapidly in a pseudo-liquid environment. At the same time, the rigid hypercrosslinked polymer ensures the overall stability of the electrolyte in extreme environments, which can not only inhibit the growth of dendrites, but also improve the antioxidant ability and service life of the solid electrolyte.

[0024] In one embodiment of the present invention, the hyper-crosslinked polymer-based electrolyte of the quasi-solid-state alkali-ion battery of the present invention comprises 50 to 200 parts by weight of an alkali-ion battery electrolyte, preferably 50 to 170 parts by weight, more preferably 50 to 160 parts by weight, more preferably 50 to 150, or preferably 70 to 200 parts by weight, more preferably 70 to 170 parts by weight, more preferably 70 to 160 parts by weight, more preferably 70 to 150 parts by weight, more preferably 90 to 150 parts by weight, more preferably 100 to 150 parts by weight, more preferably 120 to 150 parts by weight, more preferably 120 to 135 parts by weight, or 135 to 150 parts by weight of an alkali-ion battery electrolyte. Thus, better and balanced forming properties, mechanical strength, cycling performance and electrochemical performance can be obtained.

[0025] The specific surface area of the hyper-crosslinked polymer is 600 to 1400 cm 2 / g, preferably 700 to 1300 cm 2 / g, more preferably 800 to 1200 cm 2 / g, more preferably 900 to 1100 cm 2 / g. Thus, better and balanced forming properties, mechanical strength, cycling performance and electrochemical performance can be obtained.

[0026] The average pore size of the hyper-crosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, more preferably 2 to 5 nm, more preferably 2.5 to 4.5 nm. Without being bound by any theory, the inventors unexpectedly found that the above specific surface area and / or pore size provide sufficient free movement space for ions, reduce the steric hindrance during ion migration, and its continuous pore channels are conducive to maintaining the high activity of ions and improving the ionic conductivity. Thus, better and balanced forming properties, mechanical strength, cycling performance and electrochemical performance can be obtained.

[0027] The thickness of the hyper-crosslinked polymer-based electrolyte of the quasi-solid-state alkali-ion battery of the present invention is 100 - 300 μm, preferably 150 - 300 μm, more preferably 150 - 250 μm, more preferably 150 - 220 μm, more preferably 180 - 220 μm, more preferably 200 μm. Without being bound by any theory, the inventors unexpectedly found that as the electrolyte thickness increases, the bulk resistance of the electrolyte itself increases, which will cause a decrease in ionic conductivity, thus being unfavorable for ion migration. Correspondingly, a decrease in the electrolyte thickness will cause an increase in ionic conductivity, but at the same time will lead to a decrease in the mechanical properties of the electrolyte, thus weakening the inhibitory effect on sodium dendrite growth and being unfavorable for achieving the long cycling performance of the battery. Based on the above findings, the inventors further found that better and balanced forming properties, mechanical strength, cycling performance and electrochemical performance can be obtained by using the above thickness.

[0028] The monomer of the hypercrosslinked polymer of the present invention is an aromatic compound, and the aromatic compound can be selected from, for example, benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl, 4,4'-dichloromethylbiphenyl, etc., preferably selected from benzene, toluene, xylene, biphenyl and 4,4'-dimethylbiphenyl, and more preferably selected from benzene and biphenyl.

[0029] In one embodiment of the present invention, the monomer of the hypercrosslinked polymer of the present invention is selected from benzene and biphenyl. Thus, better and balanced molding properties, mechanical strength, cycling performance and electrochemical performance can be obtained.

[0030] The alkali ion battery electrolyte used in the present invention can have various classifications. For example, according to the type of battery applied, the alkali ion battery electrolyte can include a lithium ion battery electrolyte, a sodium ion battery electrolyte and a potassium ion battery electrolyte. In one embodiment of the present invention, the alkali ion battery electrolyte of the present invention can be selected from a lithium ion battery electrolyte, a sodium ion battery electrolyte and a potassium ion battery electrolyte. Among them, the lithium ion battery electrolyte can be selected from, for example, lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solutions; the sodium ion battery electrolyte can be selected from, for example, sodium hexafluorophosphate (NaPF6), sodium perchlorate (NaClO4) and sodium bis(fluorosulfonyl)imide (NaFSI) solutions; the potassium ion battery electrolyte can be selected from, for example, potassium hexafluorophosphate (KPF6), potassium bis(fluorosulfonyl)imide (KFSI) and potassium bis(trifluoromethanesulfonyl)imide (KTFSI) solutions. The solvent of the alkali ion battery electrolyte of the present invention can be selected from, for example, carbonates, ethers and their mixtures. The carbonates can include, for example, ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), etc.; the ethers can include, for example, dimethoxyethane (DME) and diethylene glycol dimethyl ether (DEGDME), etc. The alkali ion battery electrolyte of the present invention can also include additives, such as film-forming aids, flame retardants and overcharge protection agents, etc.

[0031] In a preferred embodiment of the present invention, the alkaline ion battery electrolyte of the present invention is selected from sodium ion battery electrolytes and potassium ion battery electrolytes. Among them, the sodium ion battery electrolyte is preferably selected from sodium hexafluorophosphate solution, sodium perchlorate solution and mixtures thereof, and the solvent of the sodium ion battery electrolyte is preferably selected from ethylene carbonate, diethyl carbonate and mixtures thereof. The potassium ion battery electrolyte is preferably selected from potassium hexafluorophosphate, and the solvent of the potassium ion battery electrolyte is preferably selected from ethylene carbonate, diethyl carbonate and mixtures thereof. More preferably, the solvents of the sodium ion battery electrolyte and the potassium ion battery electrolyte are a mixture of ethylene carbonate and diethyl carbonate. Further preferably, the volume ratio of ethylene carbonate to diethyl carbonate in the mixture is 1:1. Thus, better cycle performance and electrochemical performance can be obtained, and further, the properties such as excellent forming performance, high mechanical strength, good cycle performance and stable electrochemical performance can be better balanced.

[0032] In an embodiment of the present invention, the alkaline ion battery electrolyte of the present invention can be obtained in a commercially available form. For example, it can be purchased from Suzhou Duoduo Chemical Technology Co., Ltd., and the trade name can be, for example, LB-002 (the composition is 1M LiPF6 in DMC:EC:EMC = 1:1:1 Vol%), LB-008 (the composition is 1M LiPF6 in DEC:EC = 1:1 Vol%), NP-001 (the composition is 1M NaPF6 in DEC:EC = 1:1 Vol%), NS-001 (the composition is 1M NaCF3SO3 in DIGLYME = 100Vol%), NC-008 (the composition is 1 M NaClO4 in DEC:EC = 1:1 Vol %), KP-001 (the composition is 0.8 M KPF6 in EC:PC = 1:1 Vol %) or KP-044 (the composition is 1M KFSI in DEC:EC = 1:1 Vol%).

[0033] The quasi-solid-state alkaline ion battery super-crosslinked polymer-based electrolyte of the present invention may further include a binder, and the binder may be known to those skilled in the art. The binder may be selected from, for example, polyethylene oxide (PEO), polyvinylidene chloride-hexafluoropropylene (PVDF-HFP), polyacrylonitrile (PAN), polyurethane (PU), polybutadiene (PB), polytetrafluoroethylene (PTFE) and mixtures thereof.

[0034] In an embodiment of the present invention, the binder is polytetrafluoroethylene. Thus, better forming performance and mechanical strength can be obtained, and further, the properties such as excellent forming performance, high mechanical strength, good cycle performance and stable electrochemical performance can be better balanced.

[0035] In one embodiment of the present invention, the hyper-crosslinked polymer-based electrolyte of the quasi-solid-state alkali ion battery of the present invention may further include 10 to 20 parts by weight, preferably 11 to 20 parts by weight, more preferably 11 to 15 parts by weight, and even more preferably 11 to 13 parts by weight of a binder. Thus, better molding performance and mechanical strength can be obtained, and further, the excellent molding performance, high mechanical strength, good cycling performance, stable electrochemical performance and other properties can be better balanced.

[0036] According to another aspect of the present invention, the present invention also provides a method for preparing the hyper-crosslinked polymer-based electrolyte of the quasi-solid-state alkali ion battery of the present invention, including the following steps: i) Subjecting an aromatic compound and a crosslinking agent to a crosslinking reaction in the presence of a catalyst to obtain a hyper-crosslinked polymer; ii) Molding and drying the hyper-crosslinked polymer to obtain a hyper-crosslinked polymer-based film; iii) Dispersing the alkali ion battery electrolyte into the hyper-crosslinked polymer-based film by infiltration to obtain the hyper-crosslinked polymer-based electrolyte of the quasi-solid-state alkali ion battery; wherein, the weight ratio of the hyper-crosslinked polymer-based film to the alkali ion battery electrolyte dispersed in the film is 1:(0.5 to 2), preferably 1:(0.5 to 1.5), more preferably 1:(0.7 to 1.5), and even more preferably 1:(1 to 1.5); the aromatic compound is selected from benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl and 4,4'-dichloromethylbiphenyl, preferably selected from benzene, toluene, xylene, biphenyl and 4,4'-dimethylbiphenyl, and more preferably selected from benzene and biphenyl; the average pore size of the hyper-crosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, and more preferably 2 to 5 nm; the thickness of the hyper-crosslinked polymer film is 100 - 300 μm, preferably 150 - 300 μm, and more preferably 150 - 250 μm.

[0037] The aromatic compound used in the method of the present invention is the monomer of the hyper-crosslinked polymer as defined herein.

[0038] The alkali ion battery electrolyte used in the method of the present invention is as defined herein.

[0039] The crosslinking agent used in the method of the present invention can be known to those skilled in the art. The crosslinking agent can be selected from, for example, trimethyl orthoformate (TMOF), trimethyl orthoacetate (TMOA), p-dimethoxybenzene (DMB), trichlorotriazine, triethyl orthoacetate (TEOA), triisopropyl orthoformate (TIPO), tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), and dimethoxymethane (FDA), preferably selected from tetramethoxysilane, tetraethoxysilane, and dimethoxymethane. In one embodiment of the present invention, the crosslinking agent is dimethoxymethane.

[0040] The catalyst used in the method of the present invention can be known to those skilled in the art. The catalyst can be selected from, for example, sulfuric acid, p-toluenesulfonic acid (PTSA), molybdenum pentachloride (MoCl5), aluminum trichloride (AlCl3), iron trichloride (FeCl3), and zinc chloride (ZnCl2), preferably selected from molybdenum pentachloride, aluminum trichloride, iron trichloride, and zinc chloride. In one embodiment of the present invention, the catalyst is iron trichloride.

[0041] In one embodiment of the present invention, the weight ratio of the aromatic compound to the crosslinking agent is 1:(2.7 - 4.4), preferably 1:(3 - 4).

[0042] In one embodiment of the present invention, the weight ratio of the crosslinking agent to the catalyst is 1:(0.8 - 1.2), preferably 1:1.

[0043] In one embodiment of the present invention, the weight ratio of the aromatic compound to the catalyst is 1:(2.7 - 4.4), preferably 1:(3 - 4).

[0044] In one embodiment of the present invention, the weight ratio of the aromatic compound, the crosslinking agent, and the catalyst is 1:(2.7 - 4.4):(2.7 - 4.4), preferably 1:(3 - 4):(3 - 4). Thus, the specific surface area of the hypercrosslinked polymer of the present invention is 600 - 1400 cm 2 / g, preferably 700 - 1300 cm 2 / g, more preferably 800 - 1200 cm 2 / g, even more preferably 900 - 1100 cm 2 / g; the average pore diameter is 1 - 10 nm, preferably 1 - 8 nm, more preferably 2 - 5 nm, even more preferably 2.5 - 4.5 nm, in order to obtain better and balanced molding properties, mechanical strength, cycling performance, and electrochemical performance.

[0045] The reactants of the present invention can be dissolved in a solvent known to those skilled in the art to carry out the crosslinking reaction. The solvent can be selected from, for example, dichloromethane, dichloroethane, and nitromethane. In one embodiment of the present invention, the solvent is dichloroethane.

[0046] The cross-linking reaction of the present invention can be carried out under reaction conditions known to those skilled in the art. In one embodiment of the present invention, the reaction conditions for the cross-linking reaction are reacting under an inert gas (such as nitrogen, argon, etc.); the reaction temperature is 60-100 °C, preferably 70-90 °C, more preferably 75-85 °C, and even more preferably 80 °C; the reaction duration is 18-30 hours, preferably 20-28 hours, more preferably 22-26 hours, and even more preferably 24 hours. Thus, better and balanced molding properties, mechanical strength, cycling performance, and electrochemical performance can be obtained.

[0047] The molding and drying processes employed in the present invention can be carried out in a manner known to those skilled in the art. In one embodiment of the present invention, the molding can be, for example, roll pressing, so that the thickness of the hyper-crosslinked polymer-based film of the present invention reaches 100-300 μm, preferably 150-300 μm, more preferably 150-250 μm, even more preferably 150-220 μm, even more preferably 180-220 μm, and even more preferably 200 μm. Thus, better molding properties and mechanical strength can be obtained, and further, better balance among excellent molding properties, high mechanical strength, good cycling performance, and stable electrochemical performance and other properties can be achieved. The drying can be, for example, vacuum drying, and the vacuum drying is carried out, for example, at an absolute atmospheric pressure less than 0.012 Mpa, preferably less than 0.0115 Mpa, and more preferably less than 0.0114 Mpa; the drying temperature can be, for example, 80-95 °C, preferably 85-90 °C; the drying duration can be, for example, 18-30 hours, preferably 20-28 hours, more preferably 22-26 hours, and even more preferably 24 hours, so that sufficient drying can be achieved. Thus, better molding properties and mechanical strength can be obtained, and further, better balance among excellent molding properties, high mechanical strength, good cycling performance, and stable electrochemical performance and other properties can be achieved.

[0048] The infiltration process employed in the present invention can be carried out in a manner known to those skilled in the art. For example, the alkali-ion battery electrolyte is dropped onto the surface of the hyper-crosslinked polymer-based film of the present invention in small amounts and multiple times, and the alkali-ion battery electrolyte infiltrated on the film surface is sucked into the porous structure inside the film through capillary action.

[0049] In one embodiment of the present invention, the weight ratio of the hypercrosslinked polymer-based thin film to the alkali ion battery electrolyte dispersed in the thin film is 1:(0.5 - 2), preferably 1:(0.5 - 1.7), more preferably 1:(0.5 - 1.6), still more preferably 1:(0.5 - 1.5), or preferably 1:(0.7 - 2), more preferably 1:(0.7 - 1.7), more preferably 1:(0.7 - 1.6), more preferably 1:(0.7 - 1.5), still more preferably 1:(0.9 - 1.5), still more preferably 1:(1 - 1.5), still more preferably 1:(1.2 - 1.5), still more preferably 1:(1.2 - 1.35), or 1:(1.35 - 1.5). Thereby, better and balanced forming properties, mechanical strength, cycling performance, and electrochemical performance can be obtained.

[0050] In one embodiment of the present invention, the method of the present invention further includes adding a binder to the hypercrosslinked polymer before forming. Wherein, the binder used is as defined herein. The weight ratio of the hypercrosslinked polymer to the binder is 1:(0.1 - 0.2), preferably 1:(0.11 - 0.2), more preferably 1:(0.11 - 0.15), still more preferably 1:(0.11 - 0.13). Thereby, excellent forming and performance and mechanical strength can be obtained, and further, better balance among excellent forming properties, high mechanical strength, good cycling performance, and stable electrochemical performance and other properties can be achieved.

[0051] According to another aspect of the present invention, the present invention also provides an application of the quasi-solid-state alkali ion battery hypercrosslinked polymer-based electrolyte of the present invention in a secondary battery.

[0052] Embodiment In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention.

[0053] For reagents or instruments whose manufacturers are not specified, they are all commercially available conventional products commonly used in the art, or can be prepared by those skilled in the art. In the embodiments of the present invention, unless otherwise specified, all operations are carried out at room temperature and normal pressure. Unless otherwise specified, the contents and percentages in the context of this application are based on weight.

[0054] Embodiment 1 The hypercrosslinked polymer is prepared by a one-step Friedel-Crafts reaction. A microporous hypercrosslinked polymer is formed by constructing a crosslinked network structure through an external crosslinking agent dimethoxymethane (FDA) and a benzene monomer building block.

[0055] The external cross-linking agent dimethoxymethane (FDA) and benzene monomer react under the catalysis of anhydrous FeCl3 and nitrogen protection. The ratio of benzene monomer: external cross-linking agent dimethoxymethane (FDA): anhydrous FeCl3 is 1 (0.03 mol; 2.34 g): 3 (0.09 mol; 6.85 g): 3 (0.09 mol; 14.60 g). All reactants are dissolved in 200 g of dichloroethane and heated to 80 °C for 24 hours to complete the condensation reaction. The obtained product solid is washed several times with methanol, water, dichloromethane, and acetone respectively. The obtained solid powder is dried in a vacuum drying oven at 70 °C for 24 h to obtain a hypercrosslinked polymer. 0.1 g of polytetrafluoroethylene concentrated dispersion is mixed evenly with 0.8 g of phenyl hypercrosslinked polymer and then physically roll-pressed to obtain a hypercrosslinked polymer-based electrolyte membrane with a thickness of 200 μm. It is dried in a vacuum drying oven at 85 - 90 °C for 24 h under a gauge pressure of -0.09 MPa (equivalent to an absolute atmospheric pressure of 0.011325 Mpa), cut into a film with a diameter of 16 mm, and weighed with a mass of 0.1 g. 0.12 g of a commercial sodium-ion battery electrolyte (1 M NaClO4 in DEC:EC = 1:1 Vol %, Suzhou Duoduo Chemical Technology Co., Ltd., trade name NC-008) is adsorbed in the porous structure of the hypercrosslinked polymer film by infiltration (i.e., dropping a small amount of electrolyte on the film surface multiple times) to obtain a quasi-solid-state sodium-ion battery hypercrosslinked polymer-based electrolyte membrane.

[0056] The microscopic morphology of the quasi-solid-state sodium-ion battery hypercrosslinked polymer-based electrolyte membrane (i.e., the hypercrosslinked polymer-based electrolyte membrane) is as Figure 1 shown. It can be seen from Figure 1 that the prepared quasi-solid-state sodium-ion battery hypercrosslinked polymer-based electrolyte has a porous structure. The rigid hypercrosslinked polymer network framework can improve the mechanical strength of the electrolyte. This porous structure can effectively adsorb organic solvent molecules in the electrolyte, restrict the movement of anionic groups in the electrolyte, and reduce the negative impact of interfering with the migration of sodium ions.

[0057] The nitrogen adsorption and desorption test of the prepared hypercrosslinked polymer-based electrolyte membrane is carried out under the condition of liquid nitrogen at 77k. The test results are as Figure 2 and Figure 3 shown. It can be seen from Figure 2 and Figure 3 that the specific surface area of this sample is 921.62 cm 2 / g, and the average pore diameter is 4.47 nm.

[0058] For the test battery assembled with this quasi-solid electrolyte using stainless steel as the working electrode, linear voltammetry scanning test and cyclic voltammetry test of this battery are carried out at room temperature using a CHI600E electrochemical workstation. The results are asFigure 4 As shown by Figure 4 the LSV curve diagram, it can be seen that the plating / stripping potential in the curve is stable, and there is no oxidation peak except for the plating / stripping potential before 4.5 V, indicating that the prepared electrolyte has good electrochemical stability and can be adapted to the cathode material with a charging voltage below 4.5 V.

[0059] For the quasi-solid-state sodium-ion CR2032 button battery assembled with this quasi-solid-state electrolyte, a constant current charge-discharge test was carried out on this battery at room temperature using a LAND battery test system, and the test results are shown in Figure 5 . As shown by Figure 5 , the quasi-solid-state sodium-ion secondary battery assembled based on the electrolyte prepared in Example 1 has good cycle stability and can effectively improve the cycle life of the quasi-solid-state sodium-ion battery.

[0060] Embodiment 2 A hypercrosslinked polymer was prepared by a one-step Friedel-Crafts reaction. A microporous hypercrosslinked polymer was formed by constructing a crosslinked network structure through an external crosslinking agent dimethoxymethane (FDA) and a biphenyl monomer building block.

[0061] The external crosslinking agent dimethoxymethane (FDA) and the biphenyl monomer reacted under the catalysis of anhydrous FeCl3 and nitrogen protection. Biphenyl monomer: external crosslinking agent dimethoxymethane (FDA): anhydrous FeCl3 = 1 (0.03 mol; 4.63 g): 4 (0.12 mol; 9.13 g): 4 (0.12 mol; 19.46 g). All reactants were dissolved in 300 g of dichloroethane and heated to 80 °C for 24 hours to complete the condensation reaction. The obtained product solid was washed several times with methanol, water, dichloromethane, and acetone respectively. The obtained solid powder was dried in a vacuum drying oven at 70 °C for 24 h to obtain the hypercrosslinked polymer. 0.1 g of polytetrafluoroethylene concentrated dispersion was mixed evenly with 0.8 g of biphenyl-based hypercrosslinked polymer by grinding, and then a hypercrosslinked polymer-based electrolyte membrane with a thickness of 200 μm was obtained by physical roll pressing. It was dried in a vacuum drying oven at 85 - 90 °C for 24 h under a gauge pressure of -0.09 MPa (approximately equivalent to an absolute atmospheric pressure of 0.011325 Mpa), cut into a film with a diameter of 16 mm, and weighed with a mass of 0.09 g. 0.12 g of a commercial sodium-ion battery electrolyte (1 M NaPF6 in DEC:EC = 1:1 Vol %, Suzhou Duoduo Chemical Technology Co., Ltd., trade name NP-001) was adsorbed in the porous hypercrosslinked polymer film by infiltration (that is, the electrolyte was dropped on the film surface in small amounts multiple times) to obtain a hypercrosslinked polymer-based electrolyte membrane for the quasi-solid-state sodium-ion battery.

[0062] The microscopic morphology of the quasi-solid-state sodium-ion battery's hypercrosslinked polymer-based electrolyte membrane is as follows Figure 6 shown. It can be seen from Figure 6 that the prepared quasi-solid-state sodium-ion battery hypercrosslinked polymer-based electrolyte has a porous structure. The rigid hypercrosslinked polymer network framework can improve the mechanical strength of the electrolyte. This porous structure can effectively adsorb para- and organic solvent molecules in the electrolyte, restrict the movement of anion groups in the electrolyte, and reduce the negative impact interfering with sodium-ion migration.

[0063] The nitrogen adsorption and desorption test was carried out on the prepared hypercrosslinked polymer-based electrolyte membrane under the condition of liquid nitrogen at 77 K. The test results are as shown in Figure 7 and Figure 8 shown. It can be seen from Figure 7 and Figure 8 that the specific surface area of this sample is 1103.28 cm 2 / g, and the average pore diameter is 2.88 nm.

[0064] For the test battery assembled with this quasi-solid-state electrolyte using stainless steel as the working electrode, linear voltammetry scanning test and cyclic voltammetry test were carried out on this battery at room temperature using a CHI600E electrochemical workstation. The test results are as shown in Figure 9 shown. It can be seen from the LSV curve diagram in Figure 9 that the plating / stripping potential in the curve is stable, and there is no oxidation peak except for the plating / stripping potential before 4.5 V, indicating that the prepared electrolyte has good electrochemical stability and can be adapted to the positive electrode material with a charging voltage below 4.5 V.

[0065] For the quasi-solid-state sodium-ion CR2032 button battery assembled with this quasi-solid-state electrolyte, a constant current charge-discharge test was carried out on this battery at room temperature using a LAND battery test system. The test results are shown in Figure 10 . It can be seen from Figure 10 that the quasi-solid-state sodium-ion secondary battery assembled based on the electrolyte prepared in Example 2 has good cycle stability and can effectively improve the cycle life of the quasi-solid-state sodium-ion battery.

[0066] Embodiment 3 Hypercrosslinked polymers are prepared by a one-step "Friedel-Crafts" reaction. A microporous hypercrosslinked polymer is formed by constructing a crosslinked network structure through an external crosslinking agent dimethoxymethane (FDA) and a benzene monomer building block.

[0067] The external crosslinking agent dimethoxymethane (FDA) and benzene monomer react under the catalysis of anhydrous FeCl3 and the protection of argon. The ratio of benzene monomer: external crosslinking agent dimethoxymethane (FDA): anhydrous FeCl3 is 1 (0.03 mol; 2.34 g): 3 (0.09 mol; 6.85 g): 3 (0.09 mol; 14.60 g). All reactants are dissolved in 210 g of dichloroethane and heated to 80 °C for 24 hours to complete the condensation reaction. The obtained product solid is washed several times with methanol, water, dichloromethane, and acetone respectively. The obtained solid powder is dried in a vacuum drying oven at 70 °C for 24 h to obtain a hypercrosslinked polymer. 0.1 g of polytetrafluoroethylene concentrated dispersion is mixed evenly with 0.7 g of phenyl hypercrosslinked polymer by grinding, and then a hypercrosslinked polymer-based electrolyte membrane with a thickness of 200 μm is obtained by physical roll pressing. It is dried in a vacuum drying oven at 85 - 90 °C for 24 h under a gauge pressure of -0.09 Mpa (approximately equivalent to an absolute atmospheric pressure of 0.011325 Mpa), cut into a film with a diameter of 16 mm, and weighed to be 0.1 g. 0.15 g of a commercial potassium ion battery electrolyte (0.8 M KPF6 in EC:PC = 1:1 Vol %, Suzhou Duoduo Chemical Technology Co., Ltd., trade name KP-001) is adsorbed in the porous hypercrosslinked polymer film by infiltration (i.e., dropping a small amount of electrolyte on the film surface multiple times) to obtain a quasi-solid-state potassium ion battery hypercrosslinked polymer-based electrolyte membrane.

[0068] The microscopic morphology of the quasi-solid-state potassium ion battery hypercrosslinked polymer-based electrolyte membrane is as Figure 11 shown. It can be seen from Figure 11 that the prepared quasi-solid-state potassium ion battery hypercrosslinked polymer-based electrolyte has a porous structure. The rigid hypercrosslinked polymer network framework can improve the mechanical strength of the electrolyte. This porous structure can effectively adsorb the organic solvent molecules in the electrolyte, restrict the movement of anionic groups in the electrolyte, and reduce the negative impact interfering with the migration of potassium ions.

[0069] Using the quasi-solid-state electrolyte to assemble a quasi-solid-state potassium ion CR2032 type button battery, the constant current charge-discharge test of the battery is carried out at room temperature using a LAND battery test system. The test results are shown in Figure 12 . It can be seen from Figure 12 that the quasi-solid-state potassium ion secondary battery assembled based on the electrolyte prepared in Example 3 has good cycle stability and can effectively improve the cycle life of the quasi-solid-state potassium ion battery.

[0070] Comparative Example 1 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 1, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.09 g.

[0071] Comparative Example 2 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 1, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.15 g.

[0072] Comparative Example 3 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 2, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.09 g.

[0073] Comparative Example 4 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 2, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.145 g.

[0074] Comparative Example 5 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 3, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.07 g.

[0075] Comparative Example 6 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 3, except that the mass of the alkali-ion battery electrolyte adsorbed by the porous structure of the ultra-crosslinked polymer film was 0.17 g.

[0076] The preparation and performance parameters of Examples 1-3 and Comparative Examples 1-6 are compared in Table 1 below: Table 1: Comparative Example 7 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 1, except that the thickness of the ultra-crosslinked polymer film was 300 μm.

[0077] Comparative Example 8 The quasi-solid-state alkali-ion battery ultra-crosslinked polymer-based electrolyte was prepared according to the method described in Example 1, except that the thickness of the ultra-crosslinked polymer thin film was 150 μm.

[0078] The preparation and performance parameters of Example 1, Comparative Examples 7 and 8 are compared in Table 2 below: Table 2: In summary: The quasi-solid-state alkali-metal ion battery ultra-crosslinked polymer-based electrolyte prepared by the present invention has easily available raw materials and low toxicity. Moreover, the preparation process of the present invention is simple, low-cost, and easy to implement. The quasi-solid-state alkali-metal ion battery ultra-crosslinked polymer-based electrolyte prepared by the present invention has the advantages of wide operating conditions, high mechanical strength, good cycling performance, stable electrochemical performance, etc., and can be applied in secondary solid-state alkali-metal ion batteries.

Claims

1. A quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte, comprising 100 parts by weight of a hyper-crosslinked polymer, and 50 to 200 parts by weight, preferably 50 to 150 parts by weight, more preferably 70 to 150 parts by weight, more preferably 100 to 150 parts by weight of an alkali ion battery electrolyte; in, Alkali-ion battery electrolyte is dispersed in a hyper-crosslinked polymer; The monomer of the hyper-crosslinked polymer is selected from benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl and 4,4'-dichloromethylbiphenyl, preferably selected from benzene, toluene, xylene, biphenyl and 4,4'-dimethylbiphenyl, more preferably selected from benzene and biphenyl; The average pore size of the hypercrosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, more preferably 2 to 5 nm. The thickness of the hyper-crosslinked polymer is 100-300 μm, preferably 150-300 μm, more preferably 150-250 μm.

2. The quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte according to claim 1, wherein: The electrolyte of the alkali ion battery is selected from lithium hexafluorophosphate, lithium bisfluorosulfonyl imide and lithium bistrifluoromethanesulfonyl imide solutions, sodium hexafluorophosphate, sodium perchlorate and sodium bisfluorosulfonyl imide solutions, potassium hexafluorophosphate, potassium bisfluorosulfonyl imide and potassium bistrifluoromethanesulfonyl imide solutions, preferably selected from sodium hexafluorophosphate solution, sodium perchlorate solution and potassium hexafluorophosphate solution.

3. The quasi-solid-state alkali ion battery hypercrosslinked polymer-based electrolyte according to claim 1, wherein the specific surface area is 600-1400 cm 2 / g, preferably 700~1300 cm 2 / g, more preferably 800~1200 cm 2 / g.

4. The quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte according to claim 1, which may further comprise 10 to 20 parts by weight, preferably 11 to 20 parts by weight, more preferably 11 to 15 parts by weight, more preferably 11 to 13 parts by weight of a binder, The binder is selected from polyethylene oxide, polyvinylidene chloride-hexafluoropropylene, polyacrylonitrile, polyurethane, polybutadiene and polytetrafluoroethylene, preferably polytetrafluoroethylene.

5. A method for preparing a quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte according to any one of claims 1 to 4, comprising the following steps: i) allowing the aromatic compound and the cross-linking agent to undergo a cross-linking reaction in the presence of a catalyst to obtain a hyper-cross-linked polymer; ii) forming and drying the hyper-crosslinked polymer to obtain a hyper-crosslinked polymer-based film; iii) dispersing an alkali ion battery electrolyte into the hyper-crosslinked polymer-based film by infiltration to obtain a quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte; in, The weight ratio of the hyper-crosslinked polymer-based film to the alkali ion battery electrolyte dispersed in the film is 1:(0.5-2), preferably 1:(0.5-1.5), more preferably 1:(0.7-1.5), more preferably 1:(1-1.5); The aromatic compound is selected from benzene, toluene, xylene, chloromethylbenzene, biphenyl, 4,4'-dimethylbiphenyl and 4,4'-dichloromethylbiphenyl, preferably selected from benzene, toluene, xylene, biphenyl and 4,4'-dimethylbiphenyl, more preferably selected from benzene and biphenyl; The average pore size of the hyper-crosslinked polymer is 1 to 10 nm, preferably 1 to 8 nm, more preferably 2 to 5 nm; The thickness of the hyper-crosslinked polymer film is 100-300 μm, preferably 150-300 μm, more preferably 150-250 μm.

6. The method according to claim 5, wherein: The alkaline ion battery electrolyte as claimed in claim 2.

7. The method according to claim 5, wherein: The specific surface area of ​​the hypercrosslinked polymer is 600~1400 cm 2 / g, preferably 700~1300 cm 2 / g, more preferably 800~1200 cm 2 / g.

8. The method according to claim 5, further comprising adding a binder to the hyper-crosslinked polymer before forming, wherein: The weight ratio of the hypercrosslinked polymer to the binder is 1:(0.1-0.2), preferably 1:(0.11-0.2), more preferably 1:(0.11-0.15), more preferably 1:(0.11-0.13); The adhesive as claimed in claim 4.

9. The method according to claim 5, wherein: The crosslinking agent is selected from tetramethoxysilane, tetraethoxysilane and dimethoxymethane, preferably dimethoxymethane; The catalyst is selected from molybdenum pentachloride, aluminum chloride, ferric chloride and zinc chloride, preferably ferric chloride; The weight ratio of the aromatic compound to the cross-linking agent is 1:(2.7-4.4); The weight ratio of the cross-linking agent to the catalyst is 1:(0.8-1.2).

10. Use of the quasi-solid-state alkali ion battery hyper-crosslinked polymer-based electrolyte according to any one of claims 1 to 4 in secondary batteries.

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