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CN111816916B - Composite solid electrolyte membrane, preparation method thereof and lithium ion battery - Google Patents

Composite solid electrolyte membrane, preparation method thereof and lithium ion battery Download PDF

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CN111816916B
CN111816916B CN202010708652.6A CN202010708652A CN111816916B CN 111816916 B CN111816916 B CN 111816916B CN 202010708652 A CN202010708652 A CN 202010708652A CN 111816916 B CN111816916 B CN 111816916B
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lithium
electrolyte
composite solid
electrolyte membrane
fibers
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CN111816916A (en
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赵伟
李素丽
李俊义
徐延铭
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Zhuhai Cosmx Battery Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0085—Immobilising or gelification of electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

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Abstract

The invention provides a composite solid electrolyte membrane, a preparation method thereof and a lithium ion battery, and provides the composite solid electrolyte membrane which comprises a polymer electrolyte and inorganic electrolyte fibers dispersed in the polymer electrolyte, wherein an included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte membrane satisfies the following requirements: theta is more than or equal to 0 degree and less than or equal to 30 degrees. The composite solid electrolyte membrane improves the ionic conductivity and the mechanical strength of the composite solid electrolyte membrane by designing the material composition and the structure.

Description

Composite solid electrolyte membrane, preparation method thereof and lithium ion battery
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a composite solid electrolyte membrane, a preparation method thereof and a lithium ion battery.
Background
The all-solid-state battery uses the non-flammable solid electrolyte to replace flammable electrolyte in the traditional lithium ion battery, thereby fundamentally avoiding potential safety hazards. Secondly, the good mechanical property of the solid electrolyte can effectively inhibit the growth of the lithium dendrite negative electrode, thereby greatly reducing the short circuit risk caused by the penetration of the dendrite, enabling the metal lithium to be used as the negative electrode material of the lithium ion battery, and effectively improving the energy density of the lithium ion battery. The all-solid-state lithium ion battery has the advantages of high safety performance, long cycle life and the like, and the all-solid-state lithium ion battery gradually becomes a hotspot of research and development in the field of novel chemical power sources.
Therefore, the improvement of the comprehensive performance of the solid electrolyte becomes a key link in the development of the all-solid-state lithium ion battery. The solid electrolytes are mainly classified into polymer electrolytes and inorganic electrolytes, and the inorganic electrolytes are mainly classified into sulfide electrolytes and oxide electrolytes. Each of these types of solid electrolytes has advantages and disadvantages. For example, polymer electrolytes are flexible, facilitate interfacial contact in solid-state batteries, and are easily mass-produced to form electrolyte membranes, but have low ionic conductivity and are not resistant to high voltage. The sulfide electrolyte has high ionic conductivity, but is extremely unstable in air, and has high interface resistance with positive and negative electrode materials of a lithium battery. The oxide electrolyte has high ionic conductivity, but has no flexibility, and interface contact is difficult to ensure processing into a film, so that the single type of solid electrolyte cannot meet the use requirement of the current solid battery on the electrolyte film.
One of the effective solutions is to prepare a composite electrolyte membrane by compounding various electrolytes, for example, a polymer electrolyte can be compounded with an oxide electrolyte or a sulfide electrolyte to obtain a composite electrolyte membrane having both flexibility and high ionic conductivity. The polymer electrolyte can also be mixed with oxide electrolyte powder, or the polymer electrolyte is mixed with sulfide electrolyte powder, so that oxide or sulfide powder is distributed in the polymer in a discrete state, and the flexible composite electrolyte membrane with high ionic conductivity is obtained. However, since the oxide electrolyte and the sulfide electrolyte having high ionic conductivity cannot effectively form a lithium ion conductive path, the composite electrolyte prepared by the above method has a limited improvement in ionic conductivity, and the discretely distributed powder has a very limited improvement in mechanical strength of the composite electrolyte. Those skilled in the art have studied to prepare an oxide electrolyte or a sulfide electrolyte in a fibrous form and then to compound it with a polymer electrolyte in order to improve the ionic conductivity and mechanical strength of the composite electrolyte. However, the ionic conductivity and mechanical strength obtained by the existing research still can not meet the requirements of the lithium ion battery on the electrolyte membrane at present.
Therefore, providing a polymer electrolyte membrane with high ionic conductivity and mechanical strength is one of the issues that the development of all-solid lithium battery industry has been concerned with and pursued.
Disclosure of Invention
The invention provides a composite solid electrolyte membrane, which improves the ionic conductivity and mechanical strength of the composite solid electrolyte membrane by designing the material composition and structure.
The invention also provides a preparation method of the composite solid electrolyte membrane, which is simple to operate and beneficial to industrial production, and the composite solid electrolyte membrane with higher mechanical strength and ionic conductivity can be prepared by the method.
The invention also provides a lithium ion battery which has better rate performance and cycle performance compared with the existing composite solid electrolyte membrane.
The technical scheme provided by the invention is as follows:
in a first aspect, the present invention provides a composite solid electrolyte membrane comprising a polymer electrolyte, and inorganic electrolyte fibers dispersed in the polymer electrolyte, the inorganic electrolyte fibers accounting for 20 to 90% by mass of the composite solid electrolyte membrane;
the included angle theta between the length direction of the inorganic electrolyte fiber and the thickness direction of the composite solid electrolyte membrane satisfies the following condition:
0°≤θ≤30°；
Preferably, the angle θ between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte membrane is 0 °.
The composite solid electrolyte membrane improves the ionic conductivity and the mechanical strength of the composite solid electrolyte membrane by designing the material composition and the structure.
In the embodiment of the present invention, the inorganic electrolyte fiber may be a hollow fiber or a solid fiber, or may be a mixture of two types of fibers.
Specifically, the inner diameter of the inorganic electrolyte hollow fiber is about 10-2000nm, such as 50-200nm, 100-300nm, 300-500nm, 1000-2000nm, 500-1500nm, 800-1600nm, 1400-1800nm, 1200-1500nm, 250-700nm, 300-900 nm;
the outer diameter of the inorganic electrolyte hollow fiber can be 50-4000nm, 100-300nm, 700-1000nm, 100-700nm, 200-400nm, 100-200nm, 300-500nm, 1000-2000nm, 2000-4000nm, 3000-3500nm and 1500-3500 nm;
the thickness of the inorganic electrolyte hollow fiber can be 15-2000nm, such as 60-200nm, 100-200nm, 300-500nm, 400-600nm, 500-800nm, 700-1000nm, 1400-1800nm, 1200-1500nm, 100-700nm and 200-400 nm;
The solid fiber has a diameter of about 0.05-1000 μm, such as 0.1-1 μm, 0.5-20 μm, 1-10 μm, 10-100 μm, 50-200 μm, 100-300 μm, 300-500 μm, 150-400 μm, 500-1000 μm, 800-1000 μm.
In the embodiment of the present invention, the polymer electrolyte may be a lithium-conducting polymer or a non-lithium-conducting polymer, or a mixture of the two, which is not limited in the present invention. The lithium conducting polymer can be selected from one or more of polyether, polyphosphazene, polycarbonate, polyacrylate, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, nitrile rubber and polyvinyl chloride; the lithium-nonconductive polymer may be one or more selected from polyethylene, polypropylene, polyethylene terephthalate, polyurethane, polycaprolactone, silicone rubber, styrene-butadiene rubber, polystyrene, polytetrafluoroethylene, polyimide, polyether ether ketone, and epoxy resin.
In a specific embodiment of the present invention, the polymer electrolyte further includes a plasticizer, the mass fraction of the plasticizer is not more than 10% based on the mass of the composite solid electrolyte membrane, and the plasticizer is selected from at least one of a small-molecule organic plasticizer having an average molecular weight of 40 to 800 and an ionic liquid; and/or a lithium salt is further included in the polymer electrolyte, and the mass fraction of the lithium salt is not more than 10% based on the mass of the composite solid electrolyte membrane.
Wherein the organic plasticizer having an average molecular weight of 40 to 800 may be selected from ester, fluoro-ester or fluoroether plasticizers, and for example, may be selected from Ethylene Carbonate (EC), Propylene Carbonate (PC), butylene carbonate, fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), dimethyl fluorocarbonate, fluoroethylene carbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, Ethyl Methyl Carbonate (EMC), Vinylene Carbonate (VC), Vinyl Ethylene Carbonate (VEC), methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, Ethyl Acetate (EA), propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, methyl trifluoroacetate, methyl propionate, ethyl propionate, butyl butyrate, ethyl butyrate, butyl butyrate, methyl trifluoroacetate, methyl carbonate, ethyl carbonate, methyl carbonate, and the like, Methyl difluoroacetate, methyl fluoroacetate, ethyl trifluoroacetate, ethyl difluoroacetate, ethyl fluoroacetate, gamma-butyrolactone (GBL), gamma-valerolactone, delta-valerolactone, ethylene glycol dimethyl ether (DME), triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, fluoroether F-EPE, fluoroether D2, fluoroether (HFPM), fluoroether (MFE), fluoroether (EME), and may be selected from one or more of Acetonitrile (AN), malononitrile, Glutaronitrile (GN), Adiponitrile (ADN), Tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1, 3-Dioxolane (DOL), 1, 4-Dioxane (DOX), sulfolane, dimethyl sulfoxide (DMSO), dichloromethane, and dichloroethane;
The ionic liquid is selected from 1-butyl-2, 3-dimethyl imidazole bis (trifluoromethanesulfonyl) imide salt, 1-butyl-2, 3-dimethyl imidazole tetrafluoroborate, N-ethyl pyridine bis (trifluoromethanesulfonyl) imide salt, N-ethyl pyridine hexafluorophosphate and N-ethyl pyridine tetrafluoroborate, one or more of tributylmethylammonium bis (trifluoromethanesulfonyl) imide salt, N-methoxyethyl-N-methyldiethylammonium tetrafluoroborate, tributylhexylphosphine bis (trifluoromethanesulfonyl) imide salt, tetrabutylphosphine bis (trifluoromethanesulfonyl) imide salt, tributylethylphosphine bis (trifluoromethanesulfonyl) imide salt, and N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt;
the lithium ion conductivity of the composite electrolyte membrane can be further improved by adding a proper amount of lithium salt, and the lithium salt which is conventional in the field can be adopted, for example, lithium hexafluorophosphate (LiPF) can be selected6) Lithium tetrafluoroborate (LiBF)4) Lithium perchlorate (LiClO)4) Lithium hexafluoroarsenate (LiAsF)6) Lithium hexafluoroantimonate (LiSbF)6) Lithium difluorophosphate (LiPF)2O2) Lithium 4, 5-dicyano-2-trifluoromethylimidazole (LiDTI), lithium bis (oxalato) borate (LiBOB), lithium bis (malonato) borate (LiBMB), lithium difluoro (oxalato) borate (LiDFOB), lithium bis (difluoromalonato) borate (LiBDFMB), (malonato) borate (LiMOB), (difluoromalonato) oxalate lithium borate (LiDFMOB), lithium tris (oxalato) phosphate (LiTOP), tris (difluoromalonato) phosphate (phosphorous) Lithium carbonate (litfmp), lithium tetrafluoroborate phosphate (litfip), lithium difluorooxalate phosphate (litfip), lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethanesulfonylimide) (LiTFSI), and lithium (LiN (SO)2F)(SO2CF3) Lithium nitrate (LiNO), lithium nitrate (LiNO)3) Lithium fluoride (LiF), LiN (SO)2RF)2、LiN(SO2F)(SO2RF) Wherein R isF＝CnF2n+1And n is an integer of 2 to 10.
In a second aspect, the present invention provides a method for preparing the composite solid electrolyte membrane, comprising the steps of:
preparing inorganic electrolyte powder and an organic polymer into spinning solution, then carrying out coaxial electrostatic spinning to obtain composite fiber bundles arranged in a directional manner, and then calcining the composite fiber bundles at the temperature of 300-1200 ℃ for 0.5-12h to obtain the inorganic electrolyte fiber bundles. The purpose of the calcination is, on the one hand, to remove the organic polymer and, on the other hand, to sinter the fibers.
Specifically, the electrostatic spinning machine used in the invention adopts an intelligent TL-Pro-BM electrostatic spinning machine of Shenzhen Shangli Nali micro-nano science and technology Limited company and is provided with a cage-shaped yarn collector. The electrostatic spinning parameters are set within a reasonable range, so that the composite fiber can be obtained, for example, the diameter of a spinning needle tube can be controlled to be about 0.05-1000 μm, the voltage is about 10-50kV, the receiving distance is about 10-50cm, and the rotating speed of a cage-shaped filament collector is 1000-3000 r/min.
And after melting the organic electrolyte, filling the organic electrolyte into the gaps of the inorganic electrolyte fiber bundles, cooling and forming, and cutting along the direction vertical to the inorganic electrolyte fiber bundles to obtain the composite solid electrolyte film.
In the embodiment of the present invention, the inorganic electrolyte fiber may be a hollow fiber or a solid fiber, or a mixture of both.
As is well known to those skilled in the art, some solvent may be added to the dope, and if the fiber is a hollow fiber, the dope with the added solvent may be introduced into the outer tube, and air or only the solvent may be introduced into the inner tube, and then the oriented coaxial electrospinning may be performed on the electrospinning device. The solvent may be at least one selected from the group consisting of water, N-methylpyrrolidone (NMP), N-Dimethylformamide (DMF), N-dimethylacetamide (DMAc), methanol, ethanol, acetonitrile, acetone, formic acid, acetic acid, trifluoroethanol, hexafluoroisopropanol, dichloromethane, chloroform, and tetrahydrofuran. The outer and inner tube solvents may be the same or different. The present invention is not particularly limited in this regard.
Specifically, the inner diameter of the inorganic electrolyte hollow fiber is about 10-2000nm, such as 50-200nm, 100-300nm, 300-500nm, 1000-2000nm, 500-1500nm, 800-1600nm, 1400-1800nm, 1200-1500nm, 250-700nm, 300-900 nm;
The outer diameter of the inorganic electrolyte hollow fiber can be 50-4000nm, 100-;
the thickness of the inorganic electrolyte hollow fiber is not less than 15nm, such as 60-200nm, 100-200nm, 300-500nm, 400-600nm, 500-800nm, 700-1000nm, 1400-1800nm, 1200-1500nm, 100-700nm and 200-400 nm;
the solid fiber has a diameter of about 0.05-1000 μm, such as 0.1-1 μm, 0.5-20 μm, 1-10 μm, 10-100 μm, 50-200 μm, 100-300 μm, 300-500 μm, 150-400 μm, 500-1000 μm, 800-1000 μm.
In principle, the particle size of the inorganic electrolyte powder is only required to facilitate spinning, and the particle size of the powder is also required to be smaller than the size of the composite fiber, so that the particle size of the inorganic electrolyte powder can be controlled to about 10 to 900nm, for example, 200 to 500 nm.
The inorganic electrolyte powder is selected from materials of inorganic electrolytes which are conventional in the art, and for example, may be selected from one or more of lithium silicate, lithium phosphate, lithium sulfate, lithium borate, sulfide electrolyte powder, perovskite type electrolyte powder, Garnet type electrolyte powder, NASICON type electrolyte powder, LISICON type electrolyte powder, and glassy state electrolyte powder.
In particular, the sulfide electrolyte may be selected from Li2S-P2S5、Li3PS4、Li7P3S11Or Li6PS5X (X can be selected from one or more of F, Cl, Br and I); li2S-P2S5Can be 70Li2S-30P2S5、75Li2S-25P2S5Or 80Li2S-20P2S5；
The perovskite-type electrolyte may be selected from Li3zLa2/3-zTiO3Wherein z is more than 0 and less than 2/3;
the Garnet-type electrolyte may be selected from Li having a Garnet structure7-aLa3Zr2-aMaO12Wherein M can be one or more of Ta, Nb or W, and a is more than or equal to 0 and less than or equal to 2;
the NASICON-type solid electrolyte may be selected from Li1+x+yAlx(TimZrnGer)2-xSiyP3-yO12Wherein x is more than or equal to 0 and less than or equal to 2, y is more than or equal to 0 and less than or equal to 3, m is more than or equal to 0 and less than or equal to 1, n is more than or equal to 0 and less than or equal to 1, r is more than or equal to 0 and less than or equal to 1, and m + n + r is equal to 1; or Li1+2xZr2-xCax(PO4)3Wherein x is more than or equal to 0.1 and less than or equal to 0.4;
the LISICON-type electrolyte may be selected from Li4-xGe1-xPxS4(X ═ 0.4 or X ═ 0.6);
the glassy electrolyte may be selected from the group consisting of aLi2O·bAl2O3·cLa2O3·dTiO2·eZrO2·fSnO2·gZnO2·hCeO2·iB2O3·jP2O5·kSO3·mCO2·nSiO2pLiF, qLiCl, rLiBr, sLiI, where a is more than 0 and less than 1, b is more than or equal to 0 and less than 1, c is more than or equal to 0 and less than 1, d is more than or equal to 0 and less than 1, e is more than or equal to 0 and less than 1, f is more than or equal to 0 and less than 1, g is more than or equal to 0 and less than 1, h is more than or equal to 0 and less than 1, j is more than or equal to 0 and less than 1, k is more than or equal to 0 and less than 1, m is more than or equal to 0 and less than 1, r is more than or equal to 0 and less than 1, and a + b + c + d + e + f + g + h + i + j + k + n + p + q + r + s is equal to 1, and b, i, j, k and n are not equal to 0 at the same time.
The organic polymer is selected from one or more of polyglycolic acid, polylactic acid, polycaprolactone, aliphatic polyester copolymer, polyphosphazene, poly (p-dioxanone), polyamide, polycarbonate, polyurethane, polyethylene oxide, polyvinyl alcohol, polyvinyl acetal, polyacrylic acid, polyacrylate, nitrile rubber, polyacrylamide, polyvinylpyrrolidone and hydroxypropyl cellulose.
The polymer electrolyte is a polymer electrolyte conventionally used in the art, and may be, for example, one or more selected from polyethylene oxide (PEO), PEO-based copolymer, Polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polycarbonate, and polyacrylate. The polymer electrolyte can be obtained commercially or prepared by polymerizing monomers. In order to further improve the mechanical strength of the polymer electrolyte, a certain degree of crosslinking can be achieved by crosslinking, and the crosslinking can be achieved by a method conventional in the art, for example, by adding a certain amount of a crosslinking agent or by ultraviolet irradiation. When the polymer electrolyte has a certain degree of crosslinking, for example, 5 to 35%, it is possible to make the composite electrolyte membrane have both a certain mechanical strength and flexibility.
The preparation method of the composite solid electrolyte membrane is simple to operate and beneficial to industrial production. The composite solid electrolyte membrane with higher mechanical strength and ionic conductivity can be prepared by adopting the method.
In a third aspect, the invention provides a lithium ion battery, which is prepared by adopting the composite solid electrolyte membrane and is an all-solid-state lithium battery. The material of the positive electrode and the negative electrode of the lithium ion battery is not limited, for example, the positive electrode active material may be one or a mixture of several materials, for example, one or a mixture of several materials may be used in a lithium nickel cobalt manganese oxide system, a lithium iron phosphate system, a lithium vanadium lithium phosphate system, a lithium cobalt oxide system, a lithium nickelate system, a lithium manganese rich system based oxide, a lithium nickel cobalt aluminum system oxide, and a lithium manganate system, and the negative electrode material may be one or a mixture of several materials selected from a graphite negative electrode material, a silicon oxide negative electrode material, other types of silicon-based negative electrode materials, a hard carbon negative electrode material, a soft carbon negative electrode material, and a tin-based negative electrode material.
Compared with the existing composite solid electrolyte membrane, the lithium ion battery provided by the invention has better rate discharge performance and cycle life.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
Fig. 1a and 1b are schematic diagrams of aligned inorganic electrolyte fibers for preparing a composite solid electrolyte membrane according to an embodiment of the present invention, and fig. 1a is different from fig. 1b in the alignment degree of the inorganic electrolyte fibers, where θ is 0 ° in fig. 1 a; FIG. 1b is a view of 0 DEG < theta.ltoreq.30 DEG, FIG. 1c is a schematic view of a composite solid electrolyte membrane prepared from non-aligned inorganic electrolyte fibers of a comparative example of the present invention,
wherein, 1-oriented inorganic electrolyte fiber, 2-polymer electrolyte, 3-polymer electrolyte/inorganic electrolyte fiber composite, 4-composite solid electrolyte membrane;
fig. 2a, 2b, 2c are SEM images of the composite solid electrolyte membranes of fig. 1a, 1b and 1c, respectively.
Detailed Description
The following detailed description describes embodiments of the invention, which are exemplary and intended to be illustrative of the invention and are not to be construed as limiting the invention.
Fig. 1a and 1b are schematic diagrams of aligned inorganic electrolyte fibers according to an embodiment of the present invention for preparing a composite solid electrolyte membrane, as shown in fig. 1 and 2, where fig. 1a is different from fig. 1b in the alignment degree of the inorganic electrolyte fibers, and in fig. 1a, θ is 0 °; FIG. 1b shows 0 DEG < theta.ltoreq.30 DEG, and FIG. 1c shows a schematic view of a composite solid electrolyte membrane prepared from non-aligned inorganic electrolyte fibers according to a comparative example of the present invention.
The invention is described in detail below by means of specific examples:
example 1
Example 1 proposes a composite solid electrolyte membrane prepared by the following method:
(1) mixing 5 parts by weight of Li6PS5Cl (average particle diameter about 10nm), 1 part by weight of polyethylene oxide (average molecular weight about 1200 ten thousand), and 94 parts by weight of acetonitrile were formulated into a dope.
(2) Performing electrostatic spinning on the spinning solution by using a cage-shaped yarn collector to obtain a composite solid fiber bundle which is directionally arranged and has the diameter of about 500nm, wherein the spinning parameters are set as follows: the diameter of the spinning needle tube is about 500nm, the voltage is about 50kV, the receiving distance is about 50cm, and the rotating speed of the cage-shaped yarn collector is 2000 r/min.
As shown in fig. 1a and 2a, all the fibers were nearly aligned in parallel by observing the resulting solid fibers in an aligned orientation by a Scanning Electron Microscope (SEM).
(3) And then calcining the composite solid fiber bundle at the temperature of 550 ℃ for 6 hours to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing polyethylene carbonate (with an average molecular weight of 45 ten thousand) at 95 ℃, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Example 2
Example 2 proposes a composite solid electrolyte membrane prepared by the following method:
(1) mixing 8 parts by weight of Li1.5Al0.5Ge1.5(PO4)3(average particle diameter: about 100nm), 1 part by weight of polyvinyl alcohol (average molecular weight: about 40 ten thousand), and 84 parts by weight of water were prepared as a dope.
(2) Performing electrostatic spinning on the spinning solution by using a cage-shaped yarn collector to obtain a composite solid fiber bundle which is directionally arranged and has the diameter of about 800nm, wherein the spinning parameters are set as follows: the diameter of the spinning needle tube is about 800nm, the voltage is about 40kV, the receiving distance is about 40cm, and the rotating speed of the cage-shaped yarn collector is 1000 r/min.
As shown in fig. 1b and 2b, all the fibers were nearly aligned in parallel by observing the resulting solid fibers in an aligned orientation by a Scanning Electron Microscope (SEM).
(3) And calcining the composite solid fiber bundle at 1200 ℃ for 8 hours to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing polyethylene oxide (with an average molecular weight of 1200 ten thousand) at 82 ℃, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Example 3
Example 3 proposes a composite solid electrolyte membrane prepared by the following method:
(1) 16 parts by weight of Li7La3Zr2O12(average particle diameter about 800nm), 14 parts by weight of polyvinylidene fluoride alcohol (average molecular weight about 90 ten thousand), and 70 parts by weight of NMP were prepared as a dope.
(2) Performing electrostatic spinning on the spinning solution by using a cage-shaped yarn collector to obtain a composite solid fiber bundle which is directionally arranged and has the diameter of about 2000nm, wherein the spinning parameters are set as follows: the diameter of the spinning needle tube is about 2000nm, the voltage is about 45kV, the receiving distance is about 50cm, and the rotating speed of the cage-shaped yarn collecting device is 2000 r/min.
(3) And then calcining the composite solid fiber bundle at 1200 ℃ for 5 hours to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing polyethylene carbonate (with an average molecular weight of 45 ten thousand) at 95 ℃, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 60 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 30 degrees, so as to obtain the composite solid electrolyte film.
Example 4
Example 4 proposes a composite solid electrolyte membrane prepared by the following method:
(1) 4 parts by weight of lithium sulfate (average particle diameter of about 200nm), 4 parts by weight of lithium borate (average particle diameter of about 120nm), 8 parts by weight of polyvinyl formal (average molecular weight of about 30 ten thousand) and 84 parts by weight of ethanol were prepared as a spinning dope.
(2) Performing electrostatic spinning on the spinning solution by using a cage-shaped yarn collector to obtain a composite solid fiber bundle which is arranged in an oriented manner and has the diameter of about 1000nm, wherein the spinning parameters are set as follows: the diameter of the spinning needle tube is about 1000nm, the voltage is about 45kV, the receiving distance is about 45cm, and the rotating speed of the cage-shaped yarn collector is 2000 r/min.
(3) And then calcining the composite solid fiber bundle at the temperature of 1000 ℃ for 4 hours to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing 50 parts by weight of polyethylene (with an average molecular weight of 200 ten thousand) and 50 parts by weight of polypropylene (with an average molecular weight of 120 ten thousand) at 188 ℃, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Example 5
Example 5 proposes a composite solid electrolyte membrane prepared by the following method:
(1) 20 parts by weight of Li7La3Zr2O12(average particle diameter about 250nm), 10 parts by weight of polyacrylic acid (average molecular weight about 120 ten thousand), and 70 parts by weight of water were prepared as a dope.
(2) Injecting spinning stock solution into an outer tube by adopting a cage-shaped yarn collector, injecting ethanol into an inner tube, and carrying out electrostatic spinning, wherein spinning parameters are set as follows: the outer tube diameter was about 2000nm, the inner tube diameter was about 500nm, the voltage was about 90kV, and the reception distance was about 80cm, to obtain a composite hollow fiber bundle of oriented arrangement having an outer diameter of about 2000nm and an inner diameter of about 500 nm.
(3) And then calcining the composite solid fiber bundle at 1050 ℃ for 6h to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing 80 parts by weight of polyethylene carbonate (with an average molecular weight of 45 ten thousand) and 20 parts by weight of LiTFSI at 95 ℃, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Example 6
Example 6 proposes a composite solid electrolyte membrane prepared by the following method:
(1) mixing 30 parts by weight of Li1.3Al0.3Ti1.7(PO4)3(average particle diameter about 400nm), 10 parts by weight of polyvinylpyrrolidone (average molecular weight about 100 ten thousand), and 60 parts by weight of water were prepared as a dope.
(2) Injecting spinning stock solution into an outer tube by adopting a cage-shaped yarn collector, injecting ethanol into an inner tube, and carrying out electrostatic spinning, wherein spinning parameters are set as follows: the outer tube diameter was about 2200nm, the inner tube diameter was about 900nm, the voltage was about 80kV, and the reception distance was about 70cm, to obtain a bundle of composite hollow fibers having an outer diameter of about 2200nm and an inner diameter of about 900nm in a directional arrangement.
(3) And then calcining the composite solid fiber bundle at the temperature of 1100 ℃ for 2 hours to obtain the inorganic electrolyte fiber bundle.
(4) Melting 85 parts by weight of polyvinylidene fluoride (average molecular weight of 100 ten thousand), 10 parts by weight of LiDFOB and 5 parts by weight of succinonitrile at 200 ℃, uniformly mixing, filling the mixture between inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying, and cutting the mixture into a film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Example 7
Example 7 proposes a composite solid electrolyte membrane prepared by the following method:
(1) mixing 16 parts by weight of Li10GeP2S12(average particle diameter about 300nm), 10 parts by weight of nitrile rubber (average molecular weight about 60 ten thousand), and 74 parts by weight of xylene were formulated into a dope.
(2) Injecting the spinning solution into an outer tube by adopting a cage-shaped yarn collector, introducing nitrogen into an inner tube, and carrying out electrostatic spinning, wherein the spinning parameters are set as follows: the outer tube diameter was about 2500nm, the inner tube diameter was about 1200nm, the voltage was about 70kV, and the reception distance was about 50cm, to obtain a bundle of composite hollow fibers having an outer diameter of about 2500nm and an inner diameter of about 1200nm in a directional arrangement.
(3) And then calcining the composite solid fiber bundle at the temperature of 650 ℃ for 4 hours to obtain the inorganic electrolyte fiber bundle.
(4) 93 parts by weight of nitrile rubber (with an average molecular weight of 80 ten thousand), 2 parts by weight of LiTDI and 5 parts by weight of succinonitrile are melted and mixed uniformly at 180 ℃, then the mixture is filled between inorganic electrolyte fiber bundles by a vacuum filling machine, then the mixture is cooled and solidified, and then the mixture is cut into a film by a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so that the composite solid electrolyte film is obtained.
Example 8
Example 8 proposes a composite solid electrolyte membrane prepared by the following method:
(1) 10 parts by weight of lithium borate (average particle diameter of about 20nm), 4 parts by weight of polyethylene oxide (average molecular weight of about 700 ten thousand) and 84 parts by weight of acetonitrile were formulated into a spinning dope.
(2) Injecting spinning stock solution into an outer tube by adopting a cage-shaped yarn collector, injecting ethanol into an inner tube, and carrying out electrostatic spinning, wherein spinning parameters are set as follows: the outer tube diameter was about 50nm, the inner tube diameter was about 10nm, the voltage was about 65kV, and the reception distance was about 40cm, to obtain a composite hollow fiber bundle of oriented arrangement having an outer diameter of about 50nm and an inner diameter of about 10 nm.
(3) And then calcining the composite solid fiber bundle at 800 ℃ for 3h to obtain the inorganic electrolyte fiber bundle.
(4) Melting and uniformly mixing 80 parts by weight of polyethylene oxide (with an average molecular weight of 1200 ten thousand) and 10 parts by weight of LiFSI, 5 parts by weight of tetraethylene glycol dimethyl ether and 5 parts by weight of tetrabutyl phosphine bis (trifluoromethanesulfonyl) imide salt at 78 ℃, filling the mixture among inorganic electrolyte fiber bundles by using a vacuum filling machine, cooling and solidifying the mixture, and cutting the mixture into a thin film by using a precision cutting machine, wherein the included angle between the cutting direction and the length direction of the fiber bundles is 90 degrees, namely the included angle theta between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte film is 0 degree, so as to obtain the composite solid electrolyte film.
Comparative example 1
Comparative example 1 a composite solid electrolyte membrane was proposed, and comparative example 1 differs from example 1 only in that a flat plate take-up was used in step (2) of comparative example 1, and the spinning parameters were set as follows: the spinning needle had a diameter of about 0.5 μm, a voltage of about 50kV and a take-up distance of about 50 cm.
The resulting solid fibers, aligned by Scanning Electron Microscopy (SEM), were all disorderly aligned as shown in FIGS. 1c and 2 c.
Comparative example 2
Comparative example 2 a composite solid electrolyte membrane was proposed, and comparative example 2 differs from example 2 only in that a flat filament winder was used instead of a cage filament winder in step (2) of comparative example 2, and that randomly arranged fibers were prepared, and the other preparation methods and steps were the same.
Comparative example 3
Comparative example 3 proposes a composite solid electrolyte membrane, and comparative example 3 differs from example 3 only in that a flat filament winder is used instead of a cage filament winder in step (2) of comparative example 3 to prepare randomly arranged fibers, and other preparation methods and steps are the same.
Comparative example 4
Comparative example 4 a composite solid electrolyte membrane was proposed, and comparative example 4 differs from example 4 only in that a flat filament winder was used instead of a cage filament winder in step (2) of comparative example 4, and that randomly arranged fibers were prepared, and the other preparation methods and steps were the same.
Comparative example 5
Comparative example 5 a composite solid electrolyte membrane was proposed, and comparative example 5 differs from example 5 only in that a flat filament winder was used instead of a cage filament winder in step (2) of comparative example 5, and that randomly arranged fibers were prepared, and the other preparation methods and steps were the same.
Comparative example 6
Comparative example 6 a composite solid electrolyte membrane was proposed, and comparative example 6 differs from example 6 only in that a flat filament winder was used instead of a cage filament winder in step (2) of comparative example 6, and that randomly arranged fibers were prepared, and the other preparation methods and steps were the same.
Comparative example 7
Comparative example 7 proposes a composite solid electrolyte membrane, and comparative example 7 differs from example 7 only in that a flat filament winder is used instead of a cage filament winder in step (2) of comparative example 7 to prepare randomly arranged fibers, and other preparation methods and steps are the same.
Comparative example 8
Comparative example 8 a composite solid electrolyte membrane was proposed, and comparative example 8 differs from example 8 only in that a flat filament winder was used instead of a cage filament winder in step (2) of comparative example 8, and that randomly arranged fibers were produced, and the other production methods and steps were the same.
The ion conductivity and tensile strength of the composite solid electrolyte membranes of examples 1 to 8 and comparative examples 1 to 8 were measured by the following methods, respectively, and the results are shown in table 1.
Ion conductivity test
Punching the composite solid electrolyte membrane into a composite solid electrolyte membrane wafer with the radius r being 8mm by a punching machine, respectively and tightly placing stainless steel wafers (SS) with the radius r being 8mm on two sides of the composite solid electrolyte membrane wafer, and sealing and assembling the stainless steel wafers into the SS/composite solid electrolyte membrane/SS symmetrical blocking battery. And (3) carrying out alternating current impedance (EIS) test on the symmetrical blocking battery by using an electrochemical workstation, wherein the test conditions are as follows: amplitude of 10mV and frequency of 10-106Hz, the temperature is 25 ℃, the battery needs to be kept stand for 1h at the test temperature before the test to stabilize the battery, an impedance spectrum is obtained, and the body resistance R can be obtained by data fittingb. The electrical conductivity of the composite solid electrolyte membrane can be controlled byThe following equation (1) is calculated:
δ＝d/(RbS) formula (1)
Where δ is the conductivity of the composite solid electrolyte membrane, RbThe bulk resistance obtained by fitting impedance spectrum data, d is the thickness of the composite solid electrolyte membrane, S is the electrode area, and S ═ π r2。
Tensile strength
The tensile strength test method refers to the test method of the tensile property of the plastic-film of the national standard GB13022-1991 and adopts a tensile tester to test.
TABLE 1 composite solid electrolyte Membrane Performance test of examples and comparative examples
Ion conductivity (ms/cm) Tensile Strength (MPa)
Example 1 0.91 14.4
Example 2 0.78 12.5
Example 3 0.83 13.6
Example 4 0.84 29.0
Example 5 0.95 11.2
Example 6 0.97 12.7
Example 7 0.85 18.8
Example 8 1.01 11.9
Comparative example 1 0.25 4.2
Comparative example 2 0.20 3.6
Comparative example 3 0.23 4.1
Comparative example 4 0.28 9.3
Comparative example 5 0.53 7.8
Comparative example 6 0.57 8.3
Comparative example 7 0.46 7.1
Comparative example 8 0.62 5.0
As shown in table 1, the room-temperature ionic conductivity and the tensile strength of the composite solid electrolyte membrane prepared according to each example of the present invention were significantly higher than those of each comparative composite solid electrolyte membrane.
The composite solid electrolyte membranes of the comparative examples of the examples were prepared to prepare lithium ion batteries by the following method:
(1) preparation of positive pole piece
Referring to the currently general production method of the lithium ion battery, 97 parts by mass of a nickel-cobalt-manganese ternary positive electrode material (Nipponbo New energy technology Co., Ltd., nickel-cobalt lithium manganate NCM811, with a specific capacity of 191mAh/g), 1 part by mass of an acetylene black conductive agent, 0.5 part by mass of a carbon nanotube conductive agent, 1.5 parts by mass of a PVDF binder and 50 parts by mass of a solvent NMP are stirred by a double planetary stirrer under vacuum conditions of revolution of 30r/min and autorotation of 2000r/min for 4 hours to be dispersed into uniform slurry, the uniform slurry is coated on a current collector aluminum foil with the thickness of 9 mu m, then the uniform slurry is dried at 130 ℃ and rolled under 35 tons of pressure, and a positive electrode piece is obtained by slitting, wherein the surface density of the positive electrode piece is 16mg/cm 2The compacted density is 3.45g/cm3。
The fixed positive plate is used for conveniently comparing the performance of the lithium ion battery. The technical personnel can adjust the formula of the positive pole piece completely according to the specific situation. Those skilled in the art may also change the conditions of the kind of the positive electrode material, for example, the nickel-cobalt-manganese ternary positive electrode material is replaced by other common positive electrode materials of lithium ion batteries, such as lithium iron phosphate, lithium manganate, and lithium cobaltate, or the mixture of these positive electrode materials.
(2) Preparation of negative pole piece
Referring to the current general production method of the lithium ion battery, 97 parts by mass of graphite negative electrode material (artificial graphite of new energy science and technology ltd, type S360-L2-H, specific capacity 357mAh/g), 1.5 parts by mass of carbon black conductive agent, 1.0 part by mass of SBR adhesive, 0.5 part by mass of carboxymethyl cellulose and 100 parts by mass of solvent water are stirred by a double-planet stirrer under vacuum conditions of revolution of 30r/min and rotation of 1500r/min for 4H, dispersed into uniform slurry, coated on the surface of a copper foil with the thickness of 6 mu m, dried at 110 ℃, rolled under 40 tons of pressure, and finally cut into negative electrode pieces with required size, wherein the surface density of the negative electrode pieces is 9.4mg/cm 2The compacted density of the pole piece is 1.78g/cm3。
In order to compare the performance of the battery conveniently, the fixed negative pole piece is used. Technical personnel can completely adjust the formula of the negative pole piece according to specific conditions, and can also change the types of the negative pole materials, such as graphite negative pole materials, silicon oxide negative pole materials, other types of silicon-based negative pole materials, hard carbon negative pole materials, soft carbon negative pole materials, tin-based negative pole materials and the like, and mixtures of the materials in any proportion to prepare the negative pole piece. Considering that the lithium metal negative electrode frequently used in the next generation battery technology is sensitive to moisture, technicians can also directly adopt a composite foil compounded by a pure metal lithium foil, a metal lithium alloy foil, a pure metal lithium foil and a copper foil, a composite foil compounded by a metal lithium alloy foil and a copper foil, a composite foil compounded by a pure metal lithium foil and a copper foam, and a composite foil compounded by a metal lithium alloy foil and a copper foam as a negative electrode piece, and the negative electrode piece is not required to be prepared by the conventional method for preparing the negative electrode slurry and then coating the negative electrode piece.
The positive electrode plate and the negative electrode plate prepared by the above method, the composite solid electrolyte membrane prepared in each embodiment and the comparative example of the present invention, the positive electrode tab (aluminum tab of the electronic technology limited company, delphin, cloudband), and the negative electrode tab (nickel tab of the electronic technology limited company, delphin, cloudband) were prepared into a lithium ion battery by a conventional preparation process of a lithium ion battery by winding or laminating.
The room temperature rate performance and the room temperature cycle performance of the lithium ion batteries of examples 1 to 8 and comparative examples 1 to 8 were measured by the following methods, respectively, and the results are shown in table 2.
Normal temperature rate capability
Using a battery charge and discharge tester to perform charge and discharge tests on the battery at 25 ℃, wherein the charge and discharge system comprises the following steps: charging to 4.25V at 0.2C constant current, charging to 0.02C at 4.25V constant voltage, standing for 5min, discharging to 2.5V at 0.2C constant current, and recording discharge capacity Q0.2c(ii) a Standing for 5min, charging to 4.25V at 0.2C constant current, charging to 4.25V at 4.25V constant voltage until current is reduced to 0.02C, standing for 5min, discharging to 2.5V at 3C constant current, and recording discharge capacity Q3cAnd 3C discharge capacity retention ratio η ═ Q3c/Q0.2c×100％。
Normal temperature cycle performance
Using a battery charge-discharge tester to perform charge-discharge cycle test on the battery at 25 ℃, wherein the charge-discharge system comprises the following steps: charging to 4.25V at 0.5C constant current, then charging at constant voltage until the current is reduced to 0.02C, standing for 5min, discharging the battery to 2.5V at 0.5C constant current for 1 cycle, and setting the cycle number of the battery charge-discharge tester to 5000 times.
Table 2 lithium ion battery performance test of each example and comparative example
Normal temperature rate capability Cycle life
Example 1 83.1 1533
Example 2 81.4 1464
Example 3 82.0 1440
Example 4 83.8 1405
Example 5 85.7 1538
Example 6 86.3 1626
Example 7 86.2 1651
Example 8 87.1 1729
Comparative example 1 64.2 810
Comparative example 2 63.0 763
Comparative example 3 66.7 904
Comparative example 4 65.9 813
Comparative example 5 73.8 1012
Comparative example 6 73.1 1030
Comparative example 7 73.7 1058
Comparative example 8 74.3 1096
As shown in table 2, the room-temperature rate performance and the room-temperature cycle life of the lithium ion battery prepared by using the composite solid electrolyte membrane of each example of the present invention are significantly improved compared to those of the lithium ion batteries of each comparative example.
In conclusion, the composite solid electrolyte membrane improves the ionic conductivity and the mechanical strength of the composite solid electrolyte membrane by designing the material composition and the structure. Compared with the existing composite solid electrolyte membrane, the lithium ion battery has better rate capability and cycle performance.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (7)

1.一种复合固态电解质膜，其特征在于，包括聚合物电解质，以及分散在所述聚合物电解质中的无机电解质纤维，所述无机电解质纤维占所述复合固态电解质膜的质量分数20-90%；1. A composite solid electrolyte membrane, characterized by comprising a polymer electrolyte and inorganic electrolyte fibers dispersed in the polymer electrolyte, wherein the inorganic electrolyte fibers account for 20-90 mass fraction of the composite solid electrolyte membrane %; 所述无机电解质纤维的长度方向与所述复合固态电解质膜厚度方向的夹角θ满足：The angle θ between the length direction of the inorganic electrolyte fibers and the thickness direction of the composite solid electrolyte membrane satisfies: 0°＜θ≤30°；0°＜θ≤30°; 所述无机电解质纤维的原料包括硅酸锂、磷酸锂、硫酸锂、硼酸锂、钙钛矿型电解质、Garnet型电解质、NASICON型电解质、LISICON型电解质和玻璃态电解质中的一种或多种；The raw material of the inorganic electrolyte fiber includes one or more of lithium silicate, lithium phosphate, lithium sulfate, lithium borate, perovskite type electrolyte, Garnet type electrolyte, NASICON type electrolyte, LISICON type electrolyte and glass electrolyte; 所述聚合物电解质为导锂聚合物，所述导锂聚合物选自聚醚、聚磷腈、聚丙烯酸酯、丁腈橡胶和聚氯乙烯中的一种或多种；或所述聚合物电解质为不导锂聚合物，所述不导锂聚合物选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、聚氨酯、聚已内脂、硅橡胶、丁苯橡胶、聚苯乙烯、聚四氟乙烯、聚酰亚胺、聚醚醚酮和环氧树脂中的一种或多种；The polymer electrolyte is a lithium-conducting polymer, and the lithium-conducting polymer is selected from one or more of polyether, polyphosphazene, polyacrylate, nitrile rubber and polyvinyl chloride; or the polymer The electrolyte is a non-conductive lithium polymer, and the non-conductive lithium polymer is selected from polyethylene, polypropylene, polyethylene terephthalate, polyurethane, polycaprolactone, silicone rubber, styrene-butadiene rubber, polystyrene , one or more of polytetrafluoroethylene, polyimide, polyether ether ketone and epoxy resin; 所述聚合物电解质的交联度为5-35%；The cross-linking degree of the polymer electrolyte is 5-35%; 所述无机电解质纤维为中空纤维和/或实心纤维；其中所述中空纤维的内径为10-2000nm，所述无机电解质中空纤维的外径为50-4000nm，所述无机电解质中空纤维的厚度为15-2000nm；所述实心纤维的直径为0.05-1000µm。The inorganic electrolyte fibers are hollow fibers and/or solid fibers; wherein the inner diameter of the hollow fibers is 10-2000 nm, the outer diameter of the inorganic electrolyte hollow fibers is 50-4000 nm, and the thickness of the inorganic electrolyte hollow fibers is 15 nm -2000nm; the diameter of the solid fibers is 0.05-1000µm. 2.根据权利要求1所述的复合固态电解质膜，其特征在于，所述聚合物电解质中还包括增塑剂，基于所述复合固态电解质膜的质量计，所述增塑剂的质量分数不大于10%，且所述增塑剂选自平均分子量为40-800 的有机增塑剂和离子液体中的至少一种；和/或2 . The composite solid electrolyte membrane according to claim 1 , wherein the polymer electrolyte further comprises a plasticizer, and based on the mass of the composite solid electrolyte membrane, the mass fraction of the plasticizer is different. 3 . More than 10%, and the plasticizer is selected from at least one of organic plasticizers and ionic liquids with an average molecular weight of 40-800; and/or 所述聚合物电解质中还包括锂盐，基于所述复合固态电解质膜的质量计，所述锂盐的质量分数不大于10%。The polymer electrolyte further includes a lithium salt, and the mass fraction of the lithium salt is not more than 10% based on the mass of the composite solid-state electrolyte membrane. 3.根据权利要求2所述的复合固态电解质膜，其特征在于，所述平均分子量为40-800的有机增塑剂选自酯类、氟代酯类或氟代醚类增塑剂，和/或3. The composite solid electrolyte membrane according to claim 2, wherein the organic plasticizer with an average molecular weight of 40-800 is selected from the group consisting of esters, fluoroesters or fluoroethers, and /or 所述离子液体选自1-丁基-2,3-二甲基咪唑双(三氟甲烷磺酰)亚胺盐、1-丁基-2,3-二甲基咪唑四氟硼酸盐、N-乙基吡啶双(三氟甲烷磺酰)亚胺盐、N-乙基吡啶六氟磷酸盐、N-乙基吡啶四氟硼酸盐、三丁基甲基铵双(三氟甲烷磺酰)亚胺盐、 N-甲氧基乙基-N-甲基二乙基铵四氟硼酸盐、三丁基己基膦双(三氟甲烷磺酰)亚胺盐、四丁基膦双(三氟甲烷磺酰)亚胺盐、三丁基乙基膦双(三氟甲烷磺酰)亚胺盐和N-丁基-N-甲基吡咯烷双(三氟甲烷磺酰)亚胺盐中的一种或多种；和/或The ionic liquid is selected from 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine hexafluorophosphate, N-ethylpyridine tetrafluoroborate, tributylmethylammonium bis(trifluoromethanesulfonyl) Imide salt, N-methoxyethyl-N-methyldiethylammonium tetrafluoroborate, tributylhexylphosphine bis(trifluoromethanesulfonyl)imide salt, tetrabutylphosphine bis(trifluoroborate) Fluoromethanesulfonyl)imide salt, tributylethylphosphine bis(trifluoromethanesulfonyl)imide salt and N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide salt one or more of; and/or 所述锂盐选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、六氟锑酸锂、二氟磷酸锂、4,5-二氰基-2-三氟甲基咪唑锂、双乙二酸硼酸锂、双(丙二酸)硼酸锂、二氟草酸硼酸锂、双(二氟丙二酸)硼酸锂、(丙二酸草酸)硼酸锂、(二氟丙二酸草酸)硼酸锂、三(草酸)磷酸锂、三(二氟丙二酸)磷酸锂、四氟草酸磷酸锂、二氟二草酸磷酸锂、双(氟磺酰)亚胺锂、双三氟甲烷磺酰亚氨锂、(氟磺酰)(三氟甲磺酰)亚氨锂、硝酸锂、氟化锂、LiN(SO2RF)2和LiN(SO2F)(SO2RF)中的一种或多种，其中，RF=CnF2n+1，n为2-10的整数。The lithium salt is selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluoroantimonate, lithium difluorophosphate, 4,5-dicyano-2-trifluoromethylimidazole Lithium, Lithium bis(oxalate)borate, Lithium bis(malonate)borate, Lithium difluorooxalate borate, Lithium bis(difluoromalonate)borate, Lithium (malonate oxalate)borate, Lithium (difluoromalonate) Lithium oxalate) borate, lithium tris(oxalate)phosphate, lithium tris(difluoromalonate)phosphate, lithium tetrafluorooxalate phosphate, lithium difluorobisoxalate phosphate, lithium bis(fluorosulfonyl)imide, bistrifluoromethane Lithium sulfonylimide, lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide, lithium nitrate, lithium fluoride, LiN(SO 2 R F ) 2 and LiN(SO 2 F)(SO 2 R F ) One or more of , wherein, R F =C n F 2n+1 , and n is an integer of 2-10. 4.权利要求1-3任一项所述的复合固态电解质膜的制备方法，其特征在于，包括如下步骤：4. the preparation method of the composite solid-state electrolyte membrane described in any one of claim 1-3, is characterized in that, comprises the steps: 将无机电解质粉末和有机聚合物制备成纺丝原液，然后进行同轴静电纺丝，得到定向排列的复合纤维束，然后将所述复合纤维束在300-1200℃温度下煅烧0.5-12h，得到无机电解质纤维束；The inorganic electrolyte powder and the organic polymer are prepared into a spinning dope, and then coaxial electrospinning is performed to obtain an oriented composite fiber bundle, and then the composite fiber bundle is calcined at a temperature of 300-1200 ° C for 0.5-12 h to obtain Inorganic electrolyte fiber bundles; 将聚合物电解质熔融后，填充至所述无机电解质纤维束的空隙中，冷却成型后，沿垂直于所述无机电解质纤维束的方向切割，得到所述复合固态电解质膜。After the polymer electrolyte is melted, it is filled into the voids of the inorganic electrolyte fiber bundles, and after cooling and forming, the polymer electrolyte is cut along the direction perpendicular to the inorganic electrolyte fiber bundles to obtain the composite solid electrolyte membrane. 5.根据权利要求4所述的方法，其特征在于，对纺丝原液进行同轴静电纺丝，使组成所述无机电解质纤维束的纤维为中空纤维和/或实心纤维；且，5. The method according to claim 4, wherein coaxial electrospinning is performed on the spinning dope, so that the fibers constituting the inorganic electrolyte fiber bundles are hollow fibers and/or solid fibers; and, 所述无机电解质中空纤维的内径为10-2000nm，所述无机电解质中空纤维的外径为50-4000nm，所述无机电解质中空纤维的厚度不小于15nm；和/或The inner diameter of the inorganic electrolyte hollow fiber is 10-2000 nm, the outer diameter of the inorganic electrolyte hollow fiber is 50-4000 nm, and the thickness of the inorganic electrolyte hollow fiber is not less than 15 nm; and/or 所述实心纤维的直径为0.05-1000µm。The solid fibers have a diameter of 0.05-1000 µm. 6.根据权利要求4所述的方法，其特征在于，所述无机电解质粉末的粒径为10-900nm；6. The method according to claim 4, wherein the particle size of the inorganic electrolyte powder is 10-900 nm; 所述有机聚合物选自聚羟基乙酸、聚乳酸、聚已内脂、脂肪族聚酯共聚物、聚膦腈、聚对二氧六环酮、聚酰胺、聚碳酸酯、聚氨酯、聚氧化乙烯、聚乙烯醇、聚乙烯醇缩醛、聚丙烯酸、聚丙烯酸酯、丁腈橡胶、聚丙烯酰胺、聚乙烯吡咯烷酮和羟丙基纤维素中的一种或多种。The organic polymer is selected from polyglycolic acid, polylactic acid, polycaprolactone, aliphatic polyester copolymer, polyphosphazene, polydioxane, polyamide, polycarbonate, polyurethane, polyethylene oxide , one or more of polyvinyl alcohol, polyvinyl acetal, polyacrylic acid, polyacrylate, nitrile rubber, polyacrylamide, polyvinylpyrrolidone and hydroxypropyl cellulose. 7.一种锂离子电池，采用权利要求1-3任一项所述的复合固态电解质膜制备而成。7. A lithium ion battery prepared by using the composite solid electrolyte membrane of any one of claims 1-3.
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