Self-healing solid electrolyte membranes and their preparation methods, solid-state batteries and mechanical devices

Abstract

This invention provides a self-healing solid electrolyte membrane, its preparation method, a solid-state battery, and a mechanical device. The self-healing solid electrolyte membrane comprises an organic framework and a polymer electrolyte, wherein the polymer electrolyte fills the pores of the organic framework. The polymer electrolyte is formed by polymerizing a monomer and a first lithium salt within the pores of the organic framework. The monomer contains self-healing S-S bonds, and also contains C-O and C=C bonds. Therefore, this self-healing solid electrolyte membrane exhibits excellent mechanical properties and high ionic conductivity. Solid-state batteries prepared using this self-healing solid electrolyte membrane possess high energy density, long cycle life, and reliable safety.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, and in particular to a self-healing solid electrolyte membrane and its preparation method, a solid-state battery, and a mechanical device. Background Technology

[0002] The flammability and leakage of liquid electrolytes commonly used in lithium-ion batteries pose serious safety hazards. The emergence of solid-state electrolytes can effectively solve these safety problems associated with liquid electrolytes. Solid-state electrolytes also possess flame-retardant properties, significantly improving battery safety.

[0003] Solid polymer electrolytes are a type of solid electrolyte, widely used in solid-state batteries due to their good flexibility and excellent contact with electrodes. However, the low ionic conductivity and poor mechanical properties of solid polymer electrolytes make them susceptible to dendrite penetration, thus significantly reducing the electrochemical performance of the battery. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in the prior art. Therefore, one object of this invention is to provide a self-healing solid electrolyte membrane, a method for preparing the same, a solid-state battery, and a mechanical device.

[0005] In a first aspect, the present invention provides a self-healing solid electrolyte membrane. According to an embodiment of the present invention, the self-healing solid electrolyte membrane comprises:

[0006] Organic framework;

[0007] A polymer electrolyte, wherein the polymer electrolyte fills the pores of the organic framework, the polymer electrolyte being formed by polymerization of a polymeric monomer and a first lithium salt in the pores of the organic framework, the polymeric monomer containing self-healing SS bonds, and the polymeric monomer also containing CO bonds and C=C bonds.

[0008] According to the above-described self-healing solid electrolyte membrane of the present invention, an organic framework and a polymer electrolyte are included. The polymer electrolyte fills the pores of the organic framework, which provides mechanical support and enhances the mechanical properties of the solid polymer electrolyte membrane. The polymer electrolyte is formed by the polymerization of polymeric monomers and a first lithium salt within the pores of the organic framework. The polymeric monomers contain SS bonds, CO bonds, and C=C bonds. The double bonds (C=C) in the polymeric monomers enable the self-polymerization described above. The polymerization reaction takes place within the pores of the organic framework, allowing the polymeric monomers to be tightly connected and fully fill the pores of the organic framework, forming a dense, continuous, integrated polymer electrolyte structure. This self-polymerization within the pores of the organic framework not only improves the interfacial compatibility between the polymer electrolyte and the organic framework and enhances the rapid lithium-ion conduction capability, but also improves the mechanical strength of the solid polymer electrolyte membrane by enhancing the integrated polymer electrolyte structure and effectively reducing the risk of penetration by lithium dendrites. The polymer monomers contain disulfide bonds (SS), which possess the ability to break and recombine, thus endowing the solid polymer electrolyte membrane with self-healing capabilities and improving its mechanical stability. Furthermore, the introduction of sulfur-containing (-S) groups can derive a lithium-stabilized solid electrolyte interfacial phase (SEI film formation), thereby better suppressing lithium dendrite formation. Simultaneously, the polymer monomers also contain ether bonds (CO), increasing the lithium content of the electrolyte. + The site of action enhances Li + This enhances the transport capacity, thereby improving the ionic conductivity of the solid polymer electrolyte membrane. Consequently, this self-healing solid electrolyte membrane possesses excellent mechanical properties and high ionic conductivity.

[0009] In addition, the self-healing solid electrolyte membrane according to the above embodiments of the present invention also has the following technical features:

[0010] In some embodiments of the present invention, the polymeric monomer is selected from at least one of the compounds shown in general formula 1 and general formula 2;

[0011] Among them, the -R1, -CH3, and -SS-R2 groups are in The R1 is selected from hydrogen or methyl, and the R2 is selected from C1-C5 alkyl or epoxy groups;

[0012] Among them, the -R3 and -CH3-SS-R4 groups are in The R3 is selected from hydrogen or methyl, and the R4 is selected from C1-C5 alkyl or epoxy groups.

[0013] In some embodiments of the present invention, R2 is selected from methyl, ethyl, propyl, butyl, ... , or .

[0014] In some embodiments of the present invention, R4 is selected from methyl, ethyl, propyl, butyl, ... or .

[0015] In some embodiments of the present invention, the compound represented by general formula 1 includes at least one of the following structures:

[0016] , , , , , .

[0017] In some embodiments of the present invention, the compound represented by general formula 2 includes at least one of the following structures:

[0018] , , , .

[0019] In some embodiments of the present invention, the organic framework comprises a polymer and a second lithium salt.

[0020] In some embodiments of the present invention, the organic framework is a fibrous structure.

[0021] In some embodiments of the present invention, the porosity of the organic framework is 60% to 80%.

[0022] In some embodiments of the present invention, the polymer includes at least one selected from polystyrene, poly2,6-dimethyl-1,4-phenylene ether, polyimide, poly1,4-phenylene sulfide, polyphenylene dialdehyde, polystyrene-acrylonitrile, polystyrene-butadiene, polyphenylmethylsiloxane, polystyrene-allyl alcohol, polyvinyl phenylene sulfide, poly4-butyltriphenylamine, polystyrene-divinylbenzene, poly4-vinylpyridine-styrene, polybis(4-phenyl)(4-butylphenyl)amine, and polysulfone, preferably poly1,4-phenylene sulfide or polyvinyl phenylene sulfide.

[0023] In some embodiments of the present invention, the mass percentage of the second lithium salt is 5-50%, preferably 20-50%, based on the total mass of the organic framework.

[0024] In some embodiments of the present invention, the mass percentage of the first lithium salt is 5-50%, preferably 20-50%, based on the total mass of the polymer electrolyte.

[0025] In some embodiments of the present invention, the polymer electrolyte further includes inorganic fillers, and the inorganic fillers account for 5-30% of the total mass of the polymer electrolyte, preferably 20-30%.

[0026] In some embodiments of the present invention, the thickness of the self-healing solid electrolyte membrane is 50 μm-80 μm.

[0027] In a second aspect, the present invention provides a method for preparing the above-described self-healing solid electrolyte membrane. According to an embodiment of the present invention, the method includes:

[0028] The organic framework was immersed in a mixed solution containing a polymeric monomer, a first lithium salt, an initiator, and a first solvent, and then dried to obtain a self-repaired solid electrolyte membrane.

[0029] According to the preparation method of the above embodiments of the present invention, the organic framework is immersed in a mixed solution containing polymeric monomers, a first lithium salt, an initiator, and a first solvent, and then dried. The organic framework provides mechanical support, enhancing the mechanical properties of the solid polymer electrolyte membrane. During drying, under the action of the initiator, the polymeric monomers undergo a polymerization reaction. The polymerization reaction takes place in the pores of the organic framework, allowing the monomers to tightly connect and fully fill the pores, forming a dense, continuous, integrated polymer electrolyte structure. This self-polymerization within the pores of the organic framework not only improves the interfacial compatibility between the polymer electrolyte and the organic framework and enhances the rapid lithium-ion conduction capability, but also improves the mechanical strength of the solid polymer electrolyte membrane, effectively reducing the risk of lithium dendrite penetration. Therefore, this method can be used to prepare a self-healing solid electrolyte membrane with high ionic conductivity and excellent mechanical properties.

[0030] In addition, the method for preparing a self-healing solid electrolyte membrane according to the above embodiments of the present invention also has the following technical features:

[0031] In some embodiments of the present invention, the mass percentage of the first solvent in the mixed solution is 70% to 90%, preferably 70% to 80%.

[0032] In some embodiments of the present invention, the drying temperature is 60°C to 100°C, preferably 60°C to 80°C.

[0033] In some embodiments of the present invention, the soaking time is 5 min to 10 min and the temperature is 25°C to 30°C.

[0034] In some embodiments of the present invention, the method for preparing the organic framework includes: dissolving the polymer and the second lithium salt in a second solvent and then performing melt-blowing to obtain the organic framework.

[0035] In a third aspect, the present invention provides a solid-state battery. According to embodiments of the invention, the solid-state battery comprises the aforementioned self-healing solid electrolyte membrane or a self-healing solid electrolyte membrane prepared using the aforementioned method. Therefore, the solid-state battery exhibits high energy density, long cycle life, and reliable safety.

[0036] In a fourth aspect, the present invention provides a mechanical device. According to an embodiment of the invention, the mechanical device includes the aforementioned solid-state battery. Thus, the mechanical device has a long driving range and service life. Detailed Implementation

[0037] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0038] In a first aspect, the present invention provides a self-healing solid electrolyte membrane. According to an embodiment of the present invention, the self-healing solid electrolyte membrane comprises:

[0039] Organic framework;

[0040] A polymer electrolyte, wherein the polymer electrolyte fills the pores of the organic framework, the polymer electrolyte being formed by polymerization of a polymeric monomer and a first lithium salt in the pores of the organic framework, the polymeric monomer containing self-healing SS bonds, and the polymeric monomer also containing CO bonds and C=C bonds.

[0041] According to the above-described self-healing solid electrolyte membrane of the present invention, an organic framework and a polymer electrolyte are included. The polymer electrolyte fills the pores of the organic framework, which provides mechanical support and enhances the mechanical properties of the solid polymer electrolyte membrane. The polymer electrolyte is formed by the polymerization of polymeric monomers and a first lithium salt within the pores of the organic framework. The polymeric monomers contain self-healing SS bonds, as well as CO and C=C bonds. The double bonds (C=C) in the polymeric monomers enable the self-polymerization described above. The polymerization reaction takes place within the pores of the organic framework, allowing the polymeric monomers to tightly connect and fully fill the pores, forming a dense, continuous, integrated polymer electrolyte structure. This self-polymerization within the pores of the organic framework not only improves the interfacial compatibility between the polymer electrolyte and the organic framework and enhances the rapid lithium-ion conduction capability, but also improves the mechanical strength of the solid polymer electrolyte membrane by enhancing the integrated polymer electrolyte structure and effectively reducing the risk of lithium dendrite penetration. The polymer monomers contain disulfide bonds (SS), which possess the ability to break and recombine, thus endowing the solid polymer electrolyte membrane with self-healing capabilities and improving its mechanical stability. Furthermore, the introduction of sulfur-containing (-S) groups can derive a lithium-stabilized solid electrolyte interfacial phase (SEI film formation), thereby better suppressing lithium dendrite formation. Simultaneously, the polymer monomers also contain ether bonds (CO), increasing the lithium content of the electrolyte. + The site of action enhances Li + This enhances the transport capacity, thereby improving the ionic conductivity of the self-healing solid electrolyte membrane. Consequently, this self-healing solid electrolyte membrane possesses excellent mechanical properties and high ionic conductivity.

[0042] It should be noted that the first lithium salt is a conventional material in the art, and those skilled in the art can select it according to actual needs. For example, the first lithium salt includes, but is not limited to, at least one of LiTFSI, LiFSI, LiClO4, LiPF6, LiAsF6, LiBF4, LiPF4, LiBOB, LiFAB, LiODFB, LiDODFP, LiOTFP, and LiTf.

[0043] According to an embodiment of the present invention, the polymeric monomer is selected from compounds represented by general formula 1. Among them, the -R1, -CH3, and -SS-R2 groups are in The R1 is selected from hydrogen or methyl, and the R2 is selected from C1-C5 alkyl or epoxy groups.

[0044] Furthermore, R2 is selected from methyl, ethyl, propyl, butyl, , or .

[0045] As an example, the compounds represented by general formula 1 include, but are not limited to, at least one of the following structures:

[0046] , , , , , .

[0047] According to an embodiment of the present invention, the polymeric monomer is selected from compounds represented by general formula 2. Among them, the -R3 and -CH3-SS-R4 groups are in The R3 is selected from hydrogen or methyl, and the R4 is selected from C1-C5 alkyl or epoxy groups.

[0048] Furthermore, R4 is selected from methyl, ethyl, propyl, butyl, or .

[0049] As an example, the compounds represented by general formula 2 include, but are not limited to, at least one of the following structures:

[0050] , , , .

[0051] According to embodiments of the present invention, the porosity of the organic framework is 60% to 80%. A porosity within this range ensures that the self-healing solid electrolyte membrane has an appropriate amount of polymer electrolyte, thereby ensuring the high ionic conductivity of the self-healing solid electrolyte membrane. Simultaneously, the porosity within this range ensures the supporting strength of the organic framework, thereby improving the overall mechanical properties of the self-healing solid electrolyte membrane.

[0052] Furthermore, the organic framework has a fibrous structure. This fibrous structure possesses high porosity and specific surface area, thereby promoting better permeation of the polymer electrolyte and improving filling efficiency. The dense and uniform pores further facilitate the uniform distribution of the polymer electrolyte within the organic framework. Simultaneously, this organic framework also possesses high mechanical strength and toughness, significantly enhancing the mechanical stability of the solid polymer electrolyte membrane.

[0053] According to an embodiment of the present invention, the organic framework comprises a polymer and a second lithium salt. By adding a second lithium salt to the organic framework, the ionic conductivity of the organic framework can be improved, thereby enhancing the ionic conductivity of the entire self-healing solid electrolyte membrane.

[0054] It should be noted that the second lithium salt is a conventional material in the art, and those skilled in the art can select it according to actual needs. For example, the second lithium salt includes, but is not limited to, at least one of LiTFSI, LiFSI, LiClO4, LiPF6, LiAsF6, LiBF4, LiPF4, LiBOB, LiFAB, LiODFB, LiDODFP, LiOTFP, and LiTf.

[0055] According to embodiments of the present invention, the polymer comprises at least one selected from polystyrene, poly2,6-dimethyl-1,4-phenylene ether, polyimide, poly1,4-phenylene sulfide, polyphenylene dialdehyde, polystyrene-acrylonitrile, polystyrene-butadiene, polyphenylmethylsiloxane, polystyrene-allyl alcohol, polyvinylphenylene sulfide, poly4-butyltriphenylamine, polystyrene-divinylbenzene, poly4-vinylpyridine-styrene, polybis(4-phenyl)(4-butylphenyl)amine, and polysulfone, preferably poly1,4-phenylene sulfide and polyvinylphenylene sulfide. By employing the above-mentioned benzene-containing rigid organic material as an organic framework, the mechanical properties of the electrolyte membrane can be improved, and the above-mentioned organic framework can better suppress dendrite penetration. The polymer electrolyte formed by the self-polymerization of monomers in the aforementioned organic framework not only has a self-healing function, but the monomers and the organic framework can also better synergistically improve the mechanical stability of the entire electrolyte membrane. In particular, organic frameworks such as poly(1,4-phenylene sulfide) and polyvinyl phenylene sulfide can have chemical interactions with the monomers, significantly improving the interfacial compatibility between the organic framework and the polymer electrolyte, further enhancing the lithium-ion transport capacity, thereby improving the ionic conductivity and mechanical stability of the entire electrolyte membrane.

[0056] According to an embodiment of the present invention, based on the total mass of the organic framework, the mass percentage of the second lithium salt is 5-50%, preferably 20-50%. Controlling the mass percentage of the second lithium salt within the above range not only ensures the supporting strength of the organic framework but also improves the ionic conductivity of the organic framework and better synergizes with the first lithium salt in the polymer electrolyte, thereby improving the ionic conductivity of the self-healing solid electrolyte membrane.

[0057] According to an embodiment of the present invention, based on the total mass of the polymer electrolyte, the mass percentage of the first lithium salt is 5-50%, preferably 20-50%. Controlling the mass percentage of the first lithium salt within the above range can improve the ionic conductivity of the polymer electrolyte and better synergize with the first lithium salt in the organic framework, thereby improving the ionic conductivity of the self-healing solid electrolyte membrane.

[0058] According to an embodiment of the present invention, the polymer electrolyte further includes inorganic fillers, and the inorganic fillers account for 5-30% of the total mass of the polymer electrolyte, preferably 20-30%.

[0059] As an example, inorganic fillers include at least one of the following compounds: (I) P p O q , 1≤p≤2, 1≤q≤3, P is at least one of Si, Al, Ni, Ca, Mg, Ti, La or Zr; (II) (X) x O·Al2O3·ySiO2·zH2O, x=1 or 2, y≥2, X is at least one of Na, K, Ca or Ba; (III) Li 7-a La3Zr 2-a A a O 12 , 0≤a≤2, A is at least one of Ta, Nb, Sn, B, Ba, Zr, Cr, Si, Gd, In, Cu, Mo, Ge, Co, Mn, Sr, Ca, Mg, Sc, Zn, Bi, Sb, Ni, Te, Se, Ti, V, W, Hf or Y; (Ⅳ) Li 7-3b B b La3Zr2O 12 , 0≤b≤0.4, B is at least one of Al, Ga or Fe; (V) Li 7-c La 3- c C c Zr2O 12 , 0≤c≤0.8, where C is at least one of Ce or Y; (VI) Li 1+m M m Ti 2-m

[0060] (PO4)3, 0≤m<2, M is at least one of Al, Ge, In, La, Y, Ga or Lu; (VII) Li 0.5-3n La 0.5+n TiO3,0 <n<0.15;(Ⅷ)Li 6.6 La 2.75 Y 0.25 Zr 1.6 Ta 0.4 O 12 Li 6.29 Al 0.07 La3Zr 1.75 Te 0.25 O 12 Li 6.65 Ga 0.15 La3Zr 1.9 Sc 0.1 O 12 Li 5.9 Al 0.2 La3Zr 1.75 W 0.25 O12 LiZr2(PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 1.4 Al 0.4 Ti 1.4 Ge 0.2 (PO4)3, Li3Ln3Ta2O 12 or (Li 0.33 La 0.56 ) 1.005 Ti 0.99 Al 0.01 At least one of O3.

[0061] According to an embodiment of the present invention, the thickness of the self-healing solid electrolyte membrane is 50 μm to 80 μm. Controlling the thickness of the self-healing solid electrolyte membrane within the above range not only ensures the mechanical strength of the self-healing solid electrolyte membrane, but also fully utilizes the ion transport performance of the electrolyte, thereby improving the lithium-ion conductivity of the self-healing solid electrolyte membrane.

[0062] In a second aspect, the present invention provides a method for preparing the above-described self-healing solid electrolyte membrane. According to an embodiment of the present invention, the method includes:

[0063] The organic framework was immersed in a mixed solution containing a polymeric monomer, a first lithium salt, an initiator, and a first solvent, and then dried to obtain a self-repaired solid electrolyte membrane.

[0064] According to the preparation method of the above embodiments of the present invention, the organic framework is immersed in a mixed solution containing polymeric monomers, a first lithium salt, an initiator, and a first solvent, and then dried. The organic framework provides mechanical support, enhancing the mechanical properties of the self-healing solid electrolyte membrane. During drying, under the action of the initiator, the polymeric monomers undergo a polymerization reaction. The polymerization reaction takes place in the pores of the organic framework, allowing the polymeric monomers to tightly connect and fully fill the pores, forming a dense, continuous, integrated polymer electrolyte structure. This self-polymerization within the pores of the organic framework not only improves the interfacial compatibility between the polymer electrolyte and the organic framework, enhancing the rapid lithium-ion conduction capability, but also improves the mechanical strength of the self-healing solid electrolyte membrane, effectively reducing the risk of lithium dendrite penetration. Therefore, this method can be used to prepare a self-healing solid electrolyte membrane with high ionic conductivity and excellent mechanical properties.

[0065] It should be noted that the initiator and the first solvent are conventional materials in the art, and those skilled in the art can select them according to actual needs. For example, the initiator includes, but is not limited to, azobisisobutyronitrile, azobisisoheptanenitrile, azobisisovalerate, dimethyl azobisisobutyrate, di-tert-butyl azodicarbonate, and diisopropyl azodicarbonate. The first solvent includes, but is not limited to, at least one of dimethylformamide, N,N-dimethylpyrrolidone, dimethyl sulfoxide, dimethylacetamide, diethyl carbonate, dimethyl carbonate, and ethylene carbonate.

[0066] According to an embodiment of the present invention, the mass percentage of the first solvent in the mixed solution is 70% to 90%, preferably 70% to 80%. By controlling the amount of the first solvent added to the mixed solution within the above range, the polymerization precursor mixture can be rapidly impregnated with the organic framework and uniformly and fully filled into the pores of the organic framework.

[0067] According to an embodiment of the present invention, the drying temperature is 60°C to 100°C, preferably 60°C to 80°C. For example, the drying temperature is 60°C, 70°C, 80°C, 90°C, 100°C, etc., or any range between any two of the above values. By controlling the drying temperature within the above range, it can be ensured that the polymerizable monomers undergo sufficient self-polymerization reaction to form a continuous and dense electrolyte, and it can also ensure the sufficient evaporation of the first solvent.

[0068] According to an embodiment of the present invention, the impregnation time is 5 min to 10 min, and the temperature is 25°C to 30°C. By controlling the impregnation time and temperature within the above range, the polymerization precursor mixture can uniformly and fully fill the pores of the organic framework, forming a composite structure with organic framework support and self-healing electrolyte filling.

[0069] According to an embodiment of the present invention, the method for preparing the organic framework includes: dissolving the polymer and the second lithium salt in a second solvent and then performing melt-blowing to obtain the organic framework.

[0070] As an example, the screw temperature of the meltblown machine is 180°C, and the traction speed is 50 m / min. -1 .

[0071] Therefore, this method can be used to prepare self-healing solid electrolyte membranes with excellent mechanical properties and high ionic conductivity. Furthermore, the method is simple, low-cost, and suitable for widespread application. It should be noted that the characteristics and advantages described above for self-healing solid electrolyte membranes also apply to this method, and will not be repeated here.

[0072] In a third aspect, the present invention provides a solid-state battery. According to embodiments of the present invention, the solid-state battery includes the self-healing solid electrolyte membrane described above or a self-healing solid electrolyte membrane prepared using the above method. Therefore, the solid-state battery exhibits high energy density, long cycle life, and reliable safety. It should be noted that the features and advantages described above for the self-healing solid electrolyte membrane and its preparation method also apply to this solid-state battery, and will not be repeated here.

[0073] According to an embodiment of the present invention, a solid-state battery includes a positive electrode, a self-healing solid electrolyte membrane, and a negative electrode.

[0074] As an example, the main materials of the positive electrode include, but are not limited to, one or more combinations of nickel-cobalt-manganese ternary materials, nickel-cobalt-aluminum ternary materials, lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, and lithium vanadium phosphate; the main materials of the negative electrode include, but are not limited to, one or more combinations of graphite, graphene, carbon nanotubes, silicon-based alloys, silicon-oxygen negative electrodes, silicon-carbon negative electrodes, lithium metal, lithium alloy negative electrodes, lithium titanium oxides, transition metal oxides, and transition metal sulfides.

[0075] In a fourth aspect, the present invention provides a mechanical device. According to an embodiment of the invention, the mechanical device includes the aforementioned solid-state battery. Therefore, the mechanical device has a long driving range and service life. It should be noted that the features and advantages described above for the solid-state battery also apply to this mechanical device, and will not be repeated here.

[0076] According to embodiments of the present invention, the mechanical device includes, but is not limited to, motorcycles, automobiles, trucks, ships, etc.

[0077] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0078] Example 1

[0079] The preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0080] (1) Poly(1,4-phenylene sulfide) and LiTFSI were dissolved in dimethyl sulfoxide to obtain a meltblown precursor solution. The screw temperature was controlled at 180℃ and the traction speed was 50 m / min. -1 This forms a three-dimensional organic framework with a porosity of 80%. Based on the total mass of the organic framework, LiTFSI accounts for 20% of the mass.

[0081] (2) The compound of formula 1-1, LiTFSI and azobisisobutyronitrile are dissolved in dimethyl sulfoxide to obtain a mixture in which the mass fraction of dimethyl sulfoxide is 80%.

[0082] (3) The organic framework obtained in step (1) is immersed in the mixture obtained in step (2) at a temperature of 25°C for 5 minutes. After immersion, it is taken out and vacuum dried at a temperature of 80°C to obtain a self-healing solid electrolyte membrane. Based on the total mass of polymer electrolyte (mass of self-healing solid electrolyte membrane excluding organic framework), the mass ratio of LiTFSI is 20%, and the thickness of self-healing solid electrolyte membrane is 60 μm.

[0083] Example 2

[0084] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 2 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0085] In step (2) of Example 2, the polymer monomer used is a compound with the structure of Formula 1-2.

[0086] Example 3

[0087] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 3 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0088] In step (2) of Example 3, the polymer monomer used is a compound with the structure of Formula 1-5.

[0089] Example 4

[0090] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 4 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0091] In step (2) of Example 4, the polymer monomer used is a compound with the structure of Formula 2-1.

[0092] Example 5

[0093] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 5 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0094] In step (2) of Example 5, the polymer monomer used is a compound with the structure of Formula 2-2.

[0095] Example 6

[0096] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 6 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0097] In step (2) of Example 6, the polymer monomer used is a compound with the structure of Formula 2-3.

[0098] Example 7

[0099] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 7 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0100] In step (2) of Example 7, the polymer monomer used is a compound with the structure of Formula 2-4.

[0101] Example 8

[0102] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 8 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0103] The porosity of the organic framework obtained in step (1) of Example 8 is 70%.

[0104] Example 9

[0105] The difference between the preparation process of the self-healing solid electrolyte membrane in Example 9 and the preparation process of the self-healing solid electrolyte membrane in Example 1 is as follows:

[0106] The porosity of the organic framework obtained in step (1) of Example 9 is 60%.

[0107] Example 10

[0108] The preparation process of the self-healing solid electrolyte membrane in Example 10 is as follows:

[0109] (1) Poly(1,4-phenylene sulfide) was dissolved in dimethyl sulfoxide to obtain a meltblown precursor solution. The screw temperature was controlled at 180°C and the traction speed was 50 m / min. -1 This forms a three-dimensional organic framework with a porosity of 80%.

[0110] (2) The compound of formula 1-1, LiTFSI and azobisisobutyronitrile are dissolved in dimethyl sulfoxide to obtain a mixture in which the mass fraction of dimethyl sulfoxide is 80%.

[0111] (3) The organic framework obtained in step (1) is immersed in the mixture obtained in step (2) at a temperature of 25°C for 5 minutes. After immersion, it is taken out and vacuum dried at a temperature of 80°C to obtain a self-healing solid electrolyte membrane. Based on the total mass of polymer electrolyte (mass of self-healing solid electrolyte membrane excluding organic framework), the mass ratio of LiTFSI is 20%, and the thickness of self-healing solid electrolyte membrane is 55 μm.

[0112] Comparative Example 1

[0113] The preparation process of the self-healing solid electrolyte membrane in Comparative Example 1 is as follows:

[0114] (1) Poly(1,4-phenylene sulfide) and LiTFSI were dissolved in dimethyl sulfoxide to obtain a meltblown precursor solution. The screw temperature was controlled at 180℃ and the traction speed was 50 m / min. -1 This forms a three-dimensional organic framework with a porosity of 80%. Based on the total mass of the organic framework, LiTFSI accounts for 20% of the mass.

[0115] (2) Polyvinylidene fluoride and LiTFSI are dissolved in dimethyl sulfoxide to obtain a mixture with a mass fraction of 80% of dimethyl sulfoxide.

[0116] (3) The organic framework obtained in step (1) is immersed in the mixture obtained in step (2) at a temperature of 25°C for 5 minutes. After immersion, it is taken out and vacuum dried at a temperature of 80°C to obtain a solid polymer electrolyte membrane. Based on the total mass of the polymer electrolyte (the mass of the solid polymer electrolyte membrane excluding the organic framework), the mass ratio of LiTFSI is 20%, and the thickness of the self-healing solid electrolyte membrane is 60 μm.

[0117] Comparative Example 2

[0118] The preparation process of the self-healing solid electrolyte membrane in Comparative Example 1 is as follows:

[0119] (1) Poly(1,4-phenyl sulfide) and LiTFSI are dissolved in dimethyl sulfoxide to obtain a meltblown precursor solution. The screw temperature is controlled at 180°C and the traction speed is 50 m min-1 to form a three-dimensional organic framework. The porosity of the organic framework is 80%. Based on the total mass of the organic framework, the mass ratio of LiTFSI is 20%.

[0120] (2) Dissolve 2-methyl-3-methylthiofuran, LiTFSI and azobisisobutyronitrile in dimethyl sulfoxide to obtain a mixture with a mass fraction of 80% of dimethyl sulfoxide in the mixture.

[0121] (3) The organic framework obtained in step (1) is immersed in the mixture obtained in step (2) at a temperature of 25°C for 5 minutes. After immersion, it is taken out and vacuum dried at a temperature of 80°C to obtain a solid polymer electrolyte membrane. Based on the total mass of the polymer electrolyte (the mass of the solid polymer electrolyte membrane excluding the organic framework), the mass ratio of LiTFSI is 20%, and the thickness of the self-healing solid electrolyte membrane is 60 μm.

[0122] Test case

[0123] To verify the performance of the self-healing solid electrolyte membrane provided by this invention, further tests were conducted on the performance of the self-healing solid electrolyte membranes prepared in each embodiment and comparative example. Details are as follows:

[0124] (1) Ionic conductivity testing method

[0125] Assemble a stainless steel-self-healing solid electrolyte membrane-stainless steel symmetric cell and perform electrochemical impedance spectroscopy on the cell. The frequency range is 0.1 Hz-1 MHz and the test amplitude is 10 mV.

[0126] (2) Cyclic performance test

[0127] Solid-state battery assembly:

[0128] 1) Positive electrode: The mass ratio of lithium nickel cobalt manganese oxide, PVDF and conductive carbon black is 8:1:1.

[0129] 2) Use lithium metal anode as the anode plate.

[0130] 3) Assemble a solid-state battery by stacking the positive electrode, the self-healing solid electrolyte membrane, and the negative electrode in sequence.

[0131] 4) The battery was tested using the Xinwei Battery Performance Testing System. The voltage range was 2.5V-4.2V, and the charge / discharge conditions were room temperature 0.1C cycling. After 100 cycles, the corresponding capacity retention rate was calculated.

[0132] (3) Tensile strength test method

[0133] The self-healing solid electrolyte membrane was cut into strips of 8 cm × 2 cm and its tensile strength was tested using a tensile testing machine at a tensile rate of 20 mm / min.

[0134] The performance test results of the self-healing solid electrolyte membranes in the examples and comparative examples are shown in Table 1.

[0135] Table 1

[0136]

[0137] As shown in Table 1, the batteries in Examples 1-10 all exhibit good tensile strength, high ionic conductivity, and excellent cycle performance. Examples 1-7 use different polymer monomers, resulting in some differences in battery performance. The batteries prepared using polymer monomers of general formula 1 generally perform better than those prepared using polymer monomers of general formula 2. Comparing Example 1 and Comparative Example 1, the battery performance of Comparative Example 1 is significantly worse than that of Example 1. This indicates that the polymer monomers of the present invention can self-polymerize within the pores of the organic framework, achieving tight bonding and sufficient filling of the pores, significantly improving the Li content in the self-healing solid electrolyte membrane. +The connectivity is improved, and the mechanical strength is also enhanced. Comparing Example 1 and Comparative Example 2, Comparative Example 2 did not use the polymer monomer of this application, and the performance of the battery in Comparative Example 2 was worse in all aspects. This shows that the presence of -SS- in the polymer monomer of this invention endows the electrolyte membrane with self-healing ability and greatly improves the tensile strength of the self-healing solid electrolyte membrane.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-healing solid electrolyte membrane, characterized in that, include: Organic framework; A polymer electrolyte, wherein the polymer electrolyte fills the pores of the organic framework, the polymer electrolyte being formed by polymerization of a polymeric monomer and a first lithium salt in the pores of the organic framework, wherein the polymeric monomer is selected from at least one of the compounds shown in general formula 1 and general formula 2; Among them, the -R1, -CH3, and -SS-R2 groups are in The R1 is selected from hydrogen or methyl, and the R2 is selected from C1-C5 alkyl or epoxy groups; Among them, the -R3 and -CH3-SS-R4 groups are in The R3 is selected from hydrogen or methyl, and the R4 is selected from C1-C5 alkyl or epoxy groups.

2. The self-healing solid electrolyte membrane according to claim 1, characterized in that, R2 is selected from methyl, ethyl, propyl, butyl, , or ; And / or, R4 is selected from methyl, ethyl, propyl, butyl, or .

3. The self-healing solid electrolyte membrane according to claim 2, characterized in that, The compound represented by general formula 1 includes at least one of the following structures: 、 、 、 、 、 ； And / or, the compound represented by general formula 2 includes at least one of the following structures: , , , .

4. The self-healing solid electrolyte membrane according to any one of claims 1-3, characterized in that, The organic framework comprises a polymer and a second lithium salt; and / or, the organic framework has a fibrous structure; and / or, the porosity of the organic framework is 60% to 80%; and / or, the polymer comprises at least one of polystyrene, poly2,6-dimethyl-1,4-phenylene ether, polyimide, poly1,4-phenylene sulfide, polyphenylene dialdehyde, polystyrene-acrylonitrile, polystyrene-butadiene, polyphenylmethylsiloxane, polystyrene-allyl alcohol, polyvinyl phenylene sulfide, poly4-butyltriphenylamine, polystyrene-divinylbenzene, poly4-vinylpyridine-styrene, polybis(4-phenyl)(4-butylphenyl)amine, and polysulfone; and / or, based on the total mass of the organic framework, the second lithium salt accounts for 5% to 50% of the total mass.

5. The self-healing solid electrolyte membrane according to claim 4, characterized in that, The polymer is poly(1,4-phenylene sulfide) or polyvinyl phenylene sulfide; and / or, based on the total mass of the organic framework, the mass percentage of the second lithium salt is 20-50%.

6. The self-healing solid electrolyte membrane according to any one of claims 1-3, characterized in that, Based on the total mass of the polymer electrolyte, the first lithium salt accounts for 5-50% of the mass; and / or, the polymer electrolyte further includes inorganic fillers, and based on the total mass of the polymer electrolyte, the inorganic fillers account for 5-30% of the mass; and / or, the thickness of the self-healing solid electrolyte membrane is 50μm-80μm.

7. The self-healing solid electrolyte membrane according to claim 6, characterized in that, Based on the total mass of the polymer electrolyte, the first lithium salt accounts for 20-50% of the mass; and / or, based on the total mass of the polymer electrolyte, the inorganic filler accounts for 20-30% of the mass.

8. A method for preparing the self-healing solid electrolyte membrane according to any one of claims 1-7, characterized in that, include: The organic framework was immersed in a mixed solution containing a polymeric monomer, a first lithium salt, an initiator, and a first solvent, and then dried to obtain a self-repaired solid electrolyte membrane.

9. The method according to claim 8, characterized in that, The mass percentage of the first solvent in the mixed solution is 70% to 90%; and / or, the drying temperature is 60°C to 100°C; and / or, the wetting time is 5 min to 10 min and the temperature is 25°C to 30°C; and / or, the method for preparing the organic framework includes: dissolving the polymer and the second lithium salt in the second solvent and then performing melt-blowing to obtain the organic framework.

10. The method according to claim 9, characterized in that, The mass percentage of the first solvent in the mixed solution is 70% to 80%; and / or the drying temperature is 60°C to 80°C.

11. A solid-state battery, characterized in that, Includes the self-healing solid electrolyte membrane according to any one of claims 1-7 or the self-healing solid electrolyte membrane prepared by the method according to any one of claims 8-10.

12. A mechanical device, characterized in that, Includes the solid-state battery of claim 11.

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