Polyionic liquid, ceramic electrolyte film, and use

Abstract

A polyionic liquid, a ceramic electrolyte film, and a use, relating to the technical field of batteries. The polyionic liquid comprises a polymer and a first lithium salt, and the polymer is linked to the first lithium salt by means of a chemical bond. The polyionic liquid has flexibility and high conductivity, so that the ionic conductivity and stability of an electrolyte can be effectively improved.

Description

Polyionic liquids, ceramic electrolyte films and their applications

[0001] This application claims priority to Chinese Patent Application No. 202410506762.2, filed on April 25, 2024, entitled "Polyionic Liquid and Preparation Method, Composition, Ceramic Electrolyte Thin Film and Application", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a polyionic liquid, ceramic electrolyte film and its application. Background Technology

[0003] Lithium-ion batteries possess advantages such as high safety, high energy density, high voltage, and long lifespan, and are considered the most promising rechargeable batteries. Traditional lithium-ion batteries generally use organic electrolytes, but organic electrolytes pose safety hazards due to their flammability and explosiveness. Solid-state electrolytes, on the other hand, exhibit high ionic conductivity, a wide electrochemical stability window, and excellent thermodynamic properties such as high strength and elastic modulus, and are widely used in lithium-ion batteries.

[0004] Ionic liquids, as green solvents, possess advantages such as non-volatility, non-flammability, good thermal stability, chemical stability with solid electrolytes, and high ionic conductivity. They are often added to solid electrolytes to improve their performance. Combining the excellent properties of ionic liquids with polymer materials, polyionic liquids (PILs) are polymers with anionic and cationic electrolyte groups on repeating units. They exhibit high conductivity and good thermal stability, combining the advantages of both ionic liquids and polymers. However, current polyionic liquid materials offer limited improvement to the performance of solid electrolytes and require further refinement. Technical solutions

[0005] This application provides a polyionic liquid and its preparation method, a ceramic electrolyte thin film and its application.

[0006] This application provides a polyionic liquid comprising a polymer and a first lithium salt, wherein the polymer and the first lithium salt are connected by chemical bonds.

[0007] Additionally, a ceramic electrolyte film is provided, the material of which comprises a composition including a ceramic electrolyte and the aforementioned polyionic liquid.

[0008] Additionally, an electrochemical device comprising the aforementioned ceramic electrolyte membrane.

[0009] Compared with existing technologies, the polyionic liquid provided in this application has both flexibility and high conductivity, which can effectively improve the ionic conductivity and stability of electrolytes. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 is a flowchart of the preparation method of polyionic liquid provided in the embodiments of this application;

[0012] Figure 2 is a schematic diagram of the structure of the ceramic electrolyte film provided in an embodiment of this application;

[0013] Figure 3 is a schematic diagram of the structure of the composite film provided in an embodiment of this application;

[0014] Figure 4 is a schematic diagram of the battery structure provided in an embodiment of this application.

[0015] Explanation of reference numerals in the attached figures: Composite film 10; Ceramic electrolyte film 11; Polymer electrolyte film 12; Battery 100; Positive electrode 20; Negative electrode 30.

[0016] Implementation methods of this application

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] This application provides composite materials, optoelectronic devices, and methods for fabricating the same. These are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0019] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0020] In this application, expressions such as "one or more" refer to one or more of the listed items. "Multiple" refers to any combination of two or more of these items, including any combination of a single item or a plurality of items. For example, "at least one of a, b or c" or "at least one of a, b and c" can both mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0021] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 0.04 to 0.1 has specifically disclosed sub-ranges, such as from 0.04 to 0.05, from 0.05 to 0.06, from 0.06 to 0.07, from 0.07 to 0.09, etc., and single numbers within the range, such as 0.04, 0.05, and 0.06, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0022] Solid electrolytes include ceramic electrolytes and polymer electrolytes. The rigidity of ceramic electrolytes makes it difficult to buffer the volume changes of electrode materials during cycling, resulting in a loss of close contact between the ceramic electrolyte and the electrode. The ionic conductivity of existing ceramic electrolytes is still relatively low and needs further improvement.

[0023] In a first aspect, embodiments of this application provide a polyionic liquid comprising a polymer and a first lithium salt, wherein the polymer and the first lithium salt are connected by chemical bonds.

[0024] It should be noted that the polyionic liquid in this application refers to the product obtained by the ion exchange reaction between the polymer and the first lithium salt.

[0025] The polyionic liquid provided in this application comprises a polymer and a first lithium salt connected by chemical bonds. The polymer has good flexibility, which can improve interfacial contact and reduce interfacial resistance. The first lithium salt can provide lithium ions, promote ion transport, and enhance conductivity. The polyionic liquid combines the ion-conducting properties of ionic liquids with the mechanical properties of polymers. When the polyionic liquid is applied to modify electrolytes, it can significantly enhance the ionic conductivity and thermal stability of ceramic electrolytes.

[0026] In some embodiments, the polymer includes one or more of a polymer salt and a polyester. The polymer salt is a strong cationic polyelectrolyte, characterized by high conductivity and good stability; the polyester has a suitable viscosity, which can adjust the viscosity of the composition, and the polyester has low surface tension, which is beneficial for wetting, promoting film formation, and improving compatibility.

[0027] Furthermore, the polymer salt comprises polydiallyldimethylammonium chloride.

[0028] The polyester includes one or more of poly(ethylene glycol) methyl ether acrylate and polyethylene glycol diacrylate.

[0029] In some embodiments, the first lithium salt includes organic lithium salt and inorganic lithium salt.

[0030] The organic lithium salt includes one or more of lithium trifluoromethanesulfonate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium di(fluorooxalato)borate, and lithium bis(trifluoromethanesulfonyl)imide.

[0031] The inorganic lithium salt includes one or more of lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, and lithium hexafluorophosphate.

[0032] It is understood that in the polyionic liquid, the polymer is a cation, the lithium salt is an anion, and the polymer and the first lithium salt are connected by covalent bonds.

[0033] In some embodiments, the polyionic liquid includes lithium polydiallyldimethylammonium chloride-bis(trifluoromethanesulfonyl)imide, lithium polydiallyldimethylammonium chloride-lithium hexafluoroarsenate, lithium polydiallyldimethylammonium chloride-lithium hexafluorophosphate, lithium polydiallyldimethylammonium chloride-lithium bis(oxalato)borate, lithium polydiallyldimethylammonium chloride-trifluoromethanesulfonate, poly(ethylene glycol) methyl ether acrylate-bis(trifluoromethanesulfonyl)imide, and poly(ethylene glycol) methyl ether acrylate-trifluoromethanesulfonate. One or more of the following: lithium acrylate, lithium hexafluoroarsenate, lithium bis(ethylene glycol) methyl ether acrylate, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, lithium tetrafluoroborate, lithium diacrylate, lithium difluorooxalate borate, lithium trifluoromethanesulfonylimide, lithium hexafluoroarsenate, and lithium perchlorate.

[0034] In some embodiments, the mass ratio of the polymer to the first lithium salt in the polyionic liquid is (0.02–0.1):(0.04–0.2), for example, 0.06:0.06, 0.06:0.08, 0.06:0.1, 0.06:0.12, 0.06:0.14, 0.06:0.16, 0.06:0.18, 0.04:0.1, 0.06:0.1, 0.08:0.1, etc. Within the range of the mass ratio, the polymer and the first lithium salt, through synergistic effect, can efficiently improve the ionic conductivity of the electrolyte.

[0035] Please refer to Figure 1. This application also provides a method for preparing the above-mentioned polyionic liquid, including the following steps:

[0036] S11, Provide the polymer and the first lithium salt;

[0037] S12. The polymer and the first lithium salt are mixed to obtain a polyionic liquid.

[0038] It should be noted that the polymer and the first lithium salt are mixed to undergo an ion exchange reaction, resulting in a polyionic liquid.

[0039] In some embodiments, the mass ratio of the polymer to the first lithium salt is (0.02–0.1):(0.04–0.2), for example, 0.06:0.06, 0.06:0.08, 0.06:0.1, 0.06:0.12, 0.06:0.14, 0.06:0.16, 0.06:0.18, 0.04:0.1, 0.06:0.1, 0.08:0.1, etc. Within the range of these mass ratios, the polymer and the first lithium salt exhibit high reaction yields, and their synergistic effect can improve the ionic conductivity of the electrolyte.

[0040] In some embodiments, mixing the polymer and the first lithium salt includes: providing a first solvent, mixing the first solvent with the polymer and the first lithium salt to obtain a polyionic liquid.

[0041] In some embodiments, the mass ratio of the polymer to the first lithium salt to the first solvent is (0.06–0.3):(0.12–0.6), for example, 0.15:0.2, 0.15:0.3, 0.15:0.4, 0.15:0.5, 0.08:0.3, 0.1:0.3, 0.12:0.3, 0.18:0.3, 0.2:0.3, 0.22:0.3, 0.25:0.3, 0.28:0.3, etc. Within this mass ratio range, it is beneficial to create a suitable environment for the reaction between the polymer and the first lithium salt, allowing the polymer and the first lithium salt to fully and uniformly contact and react.

[0042] In some embodiments, the first solvent includes one or more of N,N-dimethylformamide (DMF), acetonitrile, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, ethyl acetate, pyrrole, butyric acid, and cresol.

[0043] In some embodiments, the polymer and the first lithium salt are mixed at room temperature.

[0044] It is understood that the mixing of the polymer and the first lithium salt can be carried out under stirring to promote uniform contact between the polymer and the first lithium salt and improve reaction efficiency.

[0045] In some embodiments, the polymer and the first lithium salt are mixed and then further dried.

[0046] Furthermore, the first drying temperature is 60℃~80℃, for example, it can be 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, etc.; the time is 8h~12h, for example, it can be 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, etc. In this way, the first solvent can be effectively removed.

[0047] Secondly, referring to Figure 2, this application embodiment also provides a ceramic electrolyte film 11, the material of which includes a composition comprising a ceramic electrolyte and the above-mentioned polyionic liquid.

[0048] The ceramic electrolyte film 11 provided in this application comprises a composition in which a polyionic liquid obtained by reacting a polymer and a first lithium salt is used to modify the ceramic electrolyte. The polymer can improve the flexibility of the ceramic electrolyte and reduce the interfacial resistance; the first lithium salt can promote ion transport and enhance conductivity; the addition of the polyionic liquid can significantly enhance the ionic conductivity and thermal stability of the ceramic electrolyte and has good interfacial contact; when the ceramic electrolyte film 11 is applied to the battery 100, it is beneficial to improve the cycle stability of the battery 100 and improve the performance of the battery 100.

[0049] In some embodiments, the ceramic electrolyte includes an oxide solid electrolyte.

[0050] In some embodiments, the oxide solid electrolyte includes one or more of perovskite-type materials, NASICON-type materials, and garnet-type materials.

[0051] The perovskite-type material includes Li a La b Ti c A d O e Wherein, 0 < a ≤ 0.5, 0 < b < 0.6, 0.9 < c ≤ 1, 0 ≤ d ≤ 0.25, 2 < e ≤ 3, and A includes one or more of Ba, Sr, and Al. For example, the perovskite material can be Li. 0.5 La 0.5 TiO3, Li 0.29 La 0.57 TiO3, Li 0.30 La 0.57 TiO3, Li 0.33 La 0.56 TiO3, Li 0.34 La 0.51 TiO 2.94 Li 0.30 La 0.567 TiO3, Li 0.36 Sr 0.04 La 0.523 TiO3, Li 0.33 Ba 0.25 La 0.39 TiO3 and (Li 0.33 La 0.56 ) 1.005 Ti 0.99 Al 0.01 One or more of O3.

[0052] The NASICON-type material (Na+superionic) includes Li f B g Ph O 12 Wherein, 1≤f≤3, 0<g≤4, 1≤h≤3, and B includes one or more of Al, Zr, Ti, Ge, and Si. For example, the NASICON-type material can be LiZr2(PO4)3, LiTi2(PO4)3, LiGe2(PO4)3, or Li... 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP), Li 1.5 Al 0.5 Ge 1.5 (PO4)3(LAGP), Li3Zr2Si2PO 12 Li 1.4 Al 0.4 Ti 1.6 (PO4)3, Li 1.4 Ti2Si 0.4 P 2.6 O 12 -AIPO4 and Li 1.5 Al 0.5 Ti 1.5 One or more of (PO4)3.

[0053] The garnet-type material includes Li i La j Zr k M l O 12 Wherein, 5≤i≤7, 2≤j≤3, 1≤k≤2, 0≤l≤1, and M is selected from any one of Ta, Nb, Hf, Al, Si, Ga, Sc, Ti, V, Y, and Sn. For example, the garnet-type material may include Li7La3Zr2O 12 Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Li 6.375 La3Zr 1.375 Nb 0.625 O 12 Li 6.85 La 2.9 Ca 0.1 Zr 1.75 Nb 0.25 O 12 Li 5.9 Al 0.2 La3Zr 1.75 W0.25 O 12 、Li7La 2.75 Ca 0.25 Zr 1.75 Nb 0.25 O 12 and Li 6.4 La3Zr 1.4 Ta 0.6 O 12 One or more of them.

[0054] In some embodiments, the ceramic electrolyte comprises ceramic electrolyte particles with an average particle size of 1 μm to 5 μm, such as 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, etc. Within the range of average particle size, the ceramic electrolyte particles have the characteristics of small particle size, good toughness, and large specific surface area, which is beneficial for contacting the polyionic liquid and improving its ionic conductivity.

[0055] In some embodiments, the mass ratio of the ceramic electrolyte to the polyionic liquid is (2.7–10):(0.06–0.3), for example, it can be 3:0.2, 4:0.2, 5:0.2, 6:0.2, 7:0.2, 0.82:0.2, 8:0.2, 9:0.2, 10:0.2, 5:0.08, 5:0.1, 5:0.12, 5:0.15, 5:0.18, 5:0.2, 5:0.22, 5:0.25, 5:0.28, etc. Within the range of the mass ratio, the polyionic liquid is beneficial for improving the ionic conductivity and stability of the ceramic electrolyte, and also beneficial for the film-forming properties when the composition is used to prepare the ceramic electrolyte film 11.

[0056] In some embodiments, the composition comprises the ceramic electrolyte and the polyionic liquid.

[0057] In some embodiments, the composition further includes a second lithium salt. The second lithium salt can further provide lithium ions, improving the conductivity of the composition, and thereby improving the conductivity of the ceramic electrolyte film 11.

[0058] In some embodiments, the second lithium salt comprises one or more of organic lithium salts and inorganic lithium salts. Further, the organic lithium salt comprises one or more of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium difluorooxalateborate (LiDFOB), and lithium bis(oxalateborate)borate (LiBOB). The inorganic lithium salt comprises one or more of lithium perchlorate (LiClO4) and lithium hexafluorophosphate (LiPF6).

[0059] The second lithium salt may be made of the same or different material as the first lithium salt.

[0060] In some embodiments, the mass ratio of the ceramic electrolyte to the second lithium salt is (2.7–10):(0.01–0.1), for example, it can be 3:0.05, 4:0.05, 5:0.05, 6:0.05, 7:0.05, 0.82:0.05, 8:0.05, 9:0.05, 10:0.05, 5:0.02, 5:0.03, 5:0.04, 5:0.06, 5:0.07, 5:0.08, 5:0.09, etc. Within the range of the mass ratio, it is beneficial for the second lithium salt to further enhance ion transport, improve the ionic conductivity of the composition, and promote the formation of a stable interface layer between the ceramic electrolyte film 11 and other film layers.

[0061] In some embodiments, the composition further includes an adhesive.

[0062] In some embodiments, the adhesive includes one or more of polyethylene oxide (PEO), polyurethane rubber (TPU), polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyaryleneacetylene (PAA), polycaprolactone (PCL), and polyvinyl butyral (PVB).

[0063] In some embodiments, the mass ratio of the ceramic electrolyte to the binder is (2.7–10): (0.5–0.6), for example, it can be 3:0.55, 4:0.55, 5:0.55, 6:0.55, 7:0.55, 0.82:0.55, 8:0.55, 9:0.55, 10:0.55, 5:0.52, 5:0.53, 5:0.54, 5:0.56, 5:0.57, 5:0.58, 5:0.59, etc. Within the range of the mass ratio, the binder has good thermoplasticity, which is beneficial for forming the materials in the composition into a whole and strengthening the tight bond between the materials.

[0064] In some embodiments, the composition comprises the ceramic electrolyte, the polyionic liquid, the second lithium salt, and the binder.

[0065] It is understood that the composition can be obtained by mixing using a dry process or a wet process.

[0066] In some embodiments, the thickness of the ceramic electrolyte film 11 is 20 μm to 40 μm, for example, it can be 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 31 μm, 33 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, etc.

[0067] This application embodiment also provides a method for preparing the above-mentioned ceramic electrolyte thin film 11, including the following steps:

[0068] S21. Provide the composition;

[0069] S22. Deposit the composition to obtain a ceramic electrolyte film 11.

[0070] The ceramic electrolyte film 11 can be prepared using a dry process or a wet process. Preferably, the ceramic electrolyte film 11 is prepared using a wet process, which results in a more uniform and flat ceramic electrolyte film 11 with a suitable thickness, thus obtaining a ceramic electrolyte film 11 with better uniformity, ductility, and mechanical properties.

[0071] Specifically, the wet process includes:

[0072] S211. A second solvent is provided and mixed with the composition to obtain a first mixture;

[0073] S212, Deposit the first mixture to obtain a ceramic electrolyte film 11.

[0074] In some embodiments, the mass ratio of the ceramic electrolyte to the second solvent is (2.7–10):(5–20), for example, 3:10, 4:10, 5:10, 6:10, 7:10, 0.82:10, 8:10, 9:10, 10:10, 5:8, 5:10, 5:12, 5:15, 5:18, etc. Within the range of the mass ratio, the second solvent can sufficiently disperse and dissolve the composition.

[0075] In some embodiments, mixing the second solvent and the composition comprises: mixing the second solvent and the ceramic electrolyte, and then adding the polyionic liquid to obtain a first mixture. It is understood that dispersing the ceramic electrolyte in the second solvent first, and then adding the polyionic liquid, facilitates the uniform dispersion of the ceramic electrolyte.

[0076] In some embodiments, the second solvent includes one or more of N,N-dimethylformamide (DMF), acetonitrile, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, ethyl acetate, pyrrole, butyric acid, and cresol.

[0077] Further, after the second solvent and the ceramic electrolyte are mixed, a first stirring is performed. The stirring speed is 600 r / min to 800 r / min, for example, 620 r / min, 650 r / min, 680 r / min, 700 r / min, 720 r / min, 750 r / min, 780 r / min, etc.; the stirring time is 5 min to 20 min, for example, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, etc. This facilitates the full dispersion of the ceramic electrolyte and avoids its aggregation and deposition.

[0078] After adding the polyionic liquid and mixing, a second stirring is performed. The stirring speed of the second stirring is 800 r / min to 1000 r / min, for example, 820 r / min, 850 r / min, 880 r / min, 900 r / min, 920 r / min, 950 r / min, 980 r / min, etc.; the stirring time is 5 min to 20 min, for example, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, etc. This facilitates sufficient and uniform contact between the polyionic liquid and the ceramic electrolyte, improving the ionic conductivity of the ceramic electrolyte.

[0079] In some embodiments, after obtaining the first mixture and before depositing the first mixture, the process further includes: degassing.

[0080] Furthermore, the degassing is performed at room temperature. The degassing time is 5 min to 20 min, for example, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, etc. The degassing includes centrifugal degassing, and the centrifugal degassing speed is 1300 r / min to 1500 r / min, for example, 1320 r / min, 1350 r / min, 1380 r / min, 1400 r / min, 1420 r / min, 1450 r / min, 1480 r / min, etc.

[0081] Thus, under the above-mentioned degassing conditions, it is beneficial to remove gas from the first mixture and promote the uniformity and stability of the ceramic electrolyte film 11.

[0082] In some embodiments, the composition further includes a second lithium salt. Mixing the first solvent and the composition includes: mixing the first solvent with the ceramic electrolyte and the second lithium salt, and then adding the polyionic liquid to obtain a first mixture.

[0083] In some embodiments, the composition further includes a binder. After obtaining the first mixture and before degassing, the process further includes adding the binder and performing a third stirring. The third stirring speed is 600 r / min to 800 r / min, for example, 620 r / min, 650 r / min, 680 r / min, 700 r / min, 720 r / min, 750 r / min, 780 r / min, etc.; the stirring time is 5 min to 20 min, for example, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, etc. Thus, the binder facilitates sufficient contact and bonding of the ceramic electrolyte, polyionic liquid, and second lithium salt into a single unit.

[0084] In some embodiments, after depositing the composition, a second drying process is further included. Further, the temperature of the second drying is 60°C to 100°C, for example, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, etc.; the time is 10h to 14h, for example, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, etc. Thus, under the conditions of the second drying, it is beneficial to remove the second solvent and form a uniform and dense ceramic electrolyte film 11.

[0085] Please refer to Figure 3. This application embodiment also provides a composite film 10, which includes the ceramic electrolyte film 11 and polymer electrolyte film 12 stacked together.

[0086] The composite film 10 provided in this application has a polymer electrolyte film 12 with good flexibility and high interface stability with lithium metal, which can work together with the ceramic electrolyte film 11 to form a stable electrode-electrolyte interface.

[0087] In some embodiments, the polymer electrolyte film 12 is made of a polymer electrolyte. Further, the polymer electrolyte comprises one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trifluoroethylene, polyethylene oxide, polyvinylidene fluoride, polymethyl methacrylate, polyurethane acrylate, polyethylene glycol, and polyvinyl alcohol. The polymer electrolyte can isolate and dissociate lithium salts and conduct lithium ions.

[0088] In some embodiments, the polymer electrolyte film 12 may further include a third lithium salt.

[0089] In some embodiments, the third lithium salt comprises one or more of organic lithium salts and inorganic lithium salts. Further, the organic lithium salt comprises one or more of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium difluorooxalate borate (LiDFOB), and lithium bis(oxalate borate) (LiBOB). The inorganic lithium salt comprises one or more of lithium perchlorate (LiClO4) and lithium hexafluorophosphate (LiPF6).

[0090] The third lithium salt may be made of the same or different materials as the second lithium salt.

[0091] In some embodiments, the mass ratio of the polymer electrolyte to the third lithium salt is (0.5–2):(0.1–1.5), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 0.8:1, 1.2:1, 1.5:1, 1.8:1, etc. Within the range of the mass ratio, the third lithium salt is beneficial for enhancing ion transport, further improving the ionic conductivity of the polymer electrolyte film 12.

[0092] In some embodiments, the polymer electrolyte film 12 is composed of the polymer electrolyte and the third lithium salt.

[0093] In some embodiments, the thickness of the polymer electrolyte film is 10 μm to 15 μm, for example, it can be 11 μm, 12 μm, 13 μm, 14 μm, etc.

[0094] Within the thickness range of the ceramic electrolyte film 11 and the polymer electrolyte film 12, it is beneficial to the interfacial contact between the ceramic electrolyte and the polymer electrolyte film. The ceramic electrolyte film 11 has excellent ionic conductivity, stability and mechanical properties, and the polymer electrolyte film 12 can promote close contact with the electrode. The two work together to give the composite film 10 good conductivity and stability.

[0095] In some embodiments, the polymer electrolyte film 12 is prepared by a wet molding process, including:

[0096] A polymer electrolyte and a third solvent are provided and mixed to obtain a second mixture.

[0097] The third mixture is deposited to obtain a polymer electrolyte film 12.

[0098] The polymer electrolyte film 12 prepared by the wet process has good uniformity and suitable thickness.

[0099] In some embodiments, the mass ratio of the polymer electrolyte to the third solvent in the mixture is (0.5–2):(5–20), for example, it can be 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 0.8:10, 1:10, 1.2:10, 1.5:10, 1.8:10, etc. Within the range of these mass ratios, it is beneficial for the polymer electrolyte to be uniformly dispersed, thereby improving the film-forming properties of the polymer electrolyte film 12.

[0100] In some embodiments, the third solvent includes one or more of N,N-dimethylformamide (DMF), acetonitrile, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, ethyl acetate, pyrrole, butyric acid, and cresol.

[0101] It is understood that the deposition of the mixture can be performed using conventional methods in the art, such as blade coating or spin coating. After the mixture is deposited, the process further includes drying to remove the third solvent, thereby obtaining the polymer electrolyte film 12. The drying conditions are the same as those for the drying of the ceramic electrolyte film 11 described above, and will not be repeated here.

[0102] After preparing the ceramic electrolyte film 11 and the polymer electrolyte film 12 respectively, the two electrolyte films are aligned and stacked to obtain the composite film 10.

[0103] Thirdly, embodiments of this application also provide an application of the above composition, the application including an electrochemical device, the electrochemical device including the above-described ceramic electrolyte film 11.

[0104] The electrochemical device can be consumer electronics, new energy vehicles, power tools, energy storage devices, etc. For example, the consumer electronics include remote controls, flashlights, alarm clocks, digital cameras, portable audio-visual devices, mobile phones, tablets, laptops, etc.; the power tools include electric vehicles, robots, etc.; and the energy storage devices include photovoltaic-energy storage power stations, wind-energy storage power stations, AGC frequency regulation power stations, substation energy storage, virtual power plants, etc.

[0105] In some embodiments, referring to FIG4, the electrochemical device includes a battery 100, the battery 100 including a positive electrode 20, a negative electrode 30 and the aforementioned ceramic electrolyte film 11, the ceramic electrolyte film 11 being located between the positive electrode 20 and the negative electrode 30.

[0106] In some embodiments, the battery 100 includes a composite film 10, which includes a ceramic electrolyte film 11 and a polymer electrolyte film 12. The composite film 10 is located between the positive electrode 20 and the negative electrode 30, and the ceramic electrolyte film 11 is located between the positive electrode 20 and the polymer electrolyte film 30.

[0107] This application employs a structure in which a ceramic electrolyte film 11 is disposed near the positive electrode 20 and a polymer electrolyte film 12 is disposed near the negative electrode 30. The ceramic electrolyte film 11 utilizes an ionic liquid-modified ceramic electrolyte improved in this application, exhibiting excellent ionic conductivity and stability, which can improve the conductivity of the battery 100. The polymer electrolyte film 12 has good uniformity and flexible mechanical properties. Covering the negative electrode 30 with it is beneficial to improve the affinity with the lithium negative electrode and can serve as a uniform and stable interface layer to promote lithium transport. The synergistic effect of the ceramic electrolyte film 11 and the polymer electrolyte film 12 can promote the stable cycling of the battery 100 system, improve the charge-discharge cycle performance of the battery 100, extend the cycle life of the battery 100, and maintain a high capacity.

[0108] In some embodiments, the material of the positive electrode 20 includes one or more of lithium nickel manganese oxide, lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, and lithium nickel cobalt manganese oxide.

[0109] In some embodiments, the negative electrode 30 includes one or more of the following: lithium metal negative electrode, lithium metal alloy negative electrode, graphite negative electrode, silicon-based negative electrode, silicon-graphite composite negative electrode, and copper foil lithium-free negative electrode.

[0110] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0111] Example 1

[0112] This embodiment provides a polyionic liquid and its preparation method, a composition containing the polyionic liquid, and a ceramic electrolyte film prepared from the composition. The preparation method is as follows:

[0113] Add 5.4g of ceramic electrolyte LLZO and 0.06g of second lithium salt LiClO4 to 7g of second solvent DMF, and stir at high speed for 10min to completely disperse LLZO;

[0114] 0.06 g of polymer polydiallyldimethylammonium chloride and 0.12 g of the first lithium salt bis(trifluoromethanesulfonyl)imide lithium salt were dissolved in the first solvent DMF under magnetic stirring. The reaction was carried out, and the solvent was evaporated and vacuum dried at 60 °C to obtain the polyionic liquid polydiallyldimethylammonium chloride bis(trifluoromethanesulfonyl)imide lithium. 0.18 g of polyionic liquid was added to the dispersed LLZO and stirred at high speed for 10 min to ensure complete dispersion.

[0115] Add 0.48g of PVDF binder, stir at high speed for 10 minutes with a mixer, and degas at room temperature using a degassing machine to obtain a first mixture; the first mixture comprises the composition;

[0116] The first mixture was coated onto a PET release film using a 250μm doctor blade and dried at 80℃ to obtain a ceramic electrolyte film with a thickness of 30μm.

[0117] Example 2

[0118] This embodiment is basically the same as Embodiment 1, except that the ceramic electrolyte LLZO is replaced with LATP (Li 1.3 Al 0.3 Ti 1.7 (PO4)3).

[0119] Example 3

[0120] This embodiment is basically the same as Embodiment 1, except that the polymer in the polyionic liquid is replaced with poly(ethylene glycol) methyl ether acrylate.

[0121] Example 4

[0122] This embodiment is basically the same as Embodiment 1, except that the first lithium salt, lithium bis(trifluoromethanesulfonyl)imide, in the polyionic liquid is replaced with lithium tetrafluoroborate.

[0123] Example 5

[0124] This embodiment is basically the same as Embodiment 1, except that the polymer in the polyionic liquid is replaced with polyethylene glycol diacrylate, and the first lithium salt, lithium bis(trifluoromethanesulfonyl)imide, in the polyionic liquid is replaced with lithium difluorooxalate borate.

[0125] Example 6

[0126] This embodiment is basically the same as Embodiment 1, except that the second lithium salt LiClO4 is replaced with LiFSI in this embodiment.

[0127] Example 7

[0128] This embodiment is basically the same as Embodiment 1, except that the adhesive PVDF is replaced with PEO in this embodiment.

[0129] Example 8

[0130] This embodiment is basically the same as Embodiment 1, except that the mass of the polymer polydiallyldimethylammonium chloride in this embodiment is 0.1g.

[0131] Example 9

[0132] This embodiment is basically the same as Embodiment 1, except that the mass of the polymer polydiallyldimethylammonium chloride in this embodiment is 0.02g.

[0133] Example 10

[0134] This embodiment is basically the same as Embodiment 1, except that the mass of the polymer polydiallyldimethylammonium chloride in this embodiment is 0.2g.

[0135] Example 11

[0136] This embodiment is basically the same as Embodiment 1, except that the mass of the polymer polydiallyldimethylammonium chloride in this embodiment is 0.01g.

[0137] Example 12

[0138] This embodiment is basically the same as Embodiment 1, except that the mass of the polyionic liquid in this embodiment is 0.5g.

[0139] Example 13

[0140] This embodiment is basically the same as Embodiment 1, except that the mass of the polyionic liquid in this embodiment is 0.06g.

[0141] Example 14

[0142] This embodiment is basically the same as Embodiment 1, except that the mass of the polyionic liquid in this embodiment is 5g.

[0143] Example 15

[0144] This embodiment is basically the same as Embodiment 1, except that the mass of the polyionic liquid in this embodiment is 0.01g.

[0145] Comparative Example 1

[0146] This comparative example is basically the same as Example 1, except that the composition in this comparative example does not contain the polyionic liquid polydiallyldimethylammonium chloride bis(trifluoromethanesulfonyl)imide lithium.

[0147] Comparative Example 2

[0148] This comparative example is basically the same as Example 1, except that the polyionic liquid polydiallyldimethylammonium chloride bis(trifluoromethanesulfonyl)imide lithium is replaced with 1-ethoxyethyl-3-methylimidazolium tetrafluoroborate.

[0149] The ionic conductivity of the compositions of Examples 1-15 and Comparative Examples 1-2 was tested respectively, and the results are shown in Table 1.

[0150] Ionic conductivity was measured by cutting the thin film into 16 mm diameter discs, assembling the discs between two stainless steel spacers to form a symmetrical cell, connecting it to an electrochemical workstation, and performing impedance testing to obtain the bulk impedance value of the sample.

[0151] The ionic conductivity is calculated using the formula σ = l / (AR), with units of S / cm; l is the thickness of the composite electrolyte membrane, with units of cm; and A is the area of ​​the composite electrolyte membrane, with units of cm². 2 R is the volume impedance of the sample to be tested, in Ω. The test results are shown in Table 1.

[0152] Table 1

[0153] As shown in Table 1:

[0154] As can be seen from Examples 1-7 and Comparative Examples 1-2, when the polyionic liquid obtained by reacting the polymer and the first lithium salt provided in this application is used to modify the ceramic electrolyte, the prepared film has a high ionic conductivity. Compared with Comparative Examples 1-2, the ionic conductivity of the ceramic electrolyte film is significantly improved.

[0155] As can be seen from Examples 1, 8-15 and Comparative Example 1, the content of polymer and first lithium salt in polyionic liquid has a significant impact on the performance of polyionic liquid. In Examples 1, 8-9, the mass ratio of polymer to first lithium salt within the preferred range provided in this application has a higher ionic conductivity than in Examples 10-11. The mass ratio of polyionic liquid to ceramic electrolyte also significantly affects the ionic conductivity of ceramic electrolyte film. In Examples 14-15, the performance of ceramic electrolyte film is improved compared to Comparative Example 1 when the mass ratio of polyionic liquid to ceramic electrolyte is high or low, but is significantly worse than the ionic conductivity when the mass ratio of polyionic liquid to ceramic electrolyte is appropriate in Examples 1, 12-13.

[0156] Application Example 1

[0157] This application example provides a composite thin film and a battery, the preparation method of which is as follows:

[0158] 0.5g of the second lithium salt LiFSI and 1.0g of the polymer electrolyte PVDF were dissolved in 10g of the second solvent DMF and stirred at room temperature for 12h to prepare a second mixture. The mixture was then coated on a glass plate using a solution casting-drying method with a 250μm doctor blade and dried at 80℃ to obtain a polymer electrolyte film with a thickness of 10μm.

[0159] The ceramic electrolyte film of Example 1 and the polymer electrolyte film described above are aligned and stacked to obtain a composite film;

[0160] Under the inert atmosphere of a glove box, the positive electrode, composite film, and negative electrode were assembled sequentially. The ceramic electrolyte film of the composite film was placed near the positive electrode, and the polymer electrolyte film was placed near the negative electrode. The assembly was completed by pressing at 800 kPa for 5 seconds to obtain the Li||NMC811 battery.

[0161] Application Examples 2-15

[0162] Application Examples 2-15 are basically the same as Application Example 1, except that the ceramic electrolyte film of Example 1 is replaced with the ceramic electrolyte film of Example 2-15 in Application Examples 2-15.

[0163] Application Example 16

[0164] Application Example 16 is basically the same as Application Example 1, except that Application Example 16 does not contain a polymer electrolyte film, but directly places the ceramic electrolyte film between the positive and negative electrodes.

[0165] Application Comparative Examples 1-2

[0166] Application Comparative Examples 1 and 2 are basically the same as Application Example 1, except that the ceramic electrolyte film of Example 1 is replaced with the ceramic electrolyte film of Comparative Examples 1 and 2 in Application Comparative Examples 1 and 2 respectively.

[0167] Application Comparative Example 3

[0168] Application Comparative Example 3 is basically the same as Application Example 1, except that Application Comparative Example 3 does not contain a ceramic electrolyte film, but directly places the polymer electrolyte film between the positive and negative electrodes.

[0169] The ionic conductivity, battery life, and capacity retention of the composite films used in Examples 1-16 and Comparative Examples 1-3 were tested respectively, and the data results are shown in Table 2.

[0170] The test method for lifespan is as follows: the battery is subjected to a test at 25°C with a current of 2mA / cm. 2 Current density, 2mAh / cm 2 The battery life is determined by testing the load capacity and the time it takes for the battery to experience a hard short circuit or polarization potential > 0.5V.

[0171] The test method for capacity retention (cycle curve) is as follows: the battery is charged to 4.2V at 0.33C constant current and constant voltage at 25℃, and then discharged to 3.0V at 0.5C constant current. This constitutes one cycle. The remaining capacity is the capacity retention rate. The cycle number or capacity retention rate of each battery is compared.

[0172] Table 2

[0173] As shown in Table 2:

[0174] As can be seen from Application Examples 1-7 and Comparative Examples 1-2, the composite film provided by this application has a higher ionic conductivity than the comparative examples, and the battery has better cycle performance. This is mainly because the mass ratio of polymer to first lithium salt in the polyionic liquid provided by this application is appropriate, and the mass ratio of polyionic liquid to ceramic electrolyte is appropriate, so that the components can work synergistically to more effectively improve the cycle performance of the battery.

[0175] As can be seen from Application Examples 1, 8-15 and Comparative Example 1, the ratio of each component in the composition affects the performance of the composition, and further affects the performance of the battery. In Application Examples 10-11, the mass ratio of the polymer to the first lithium salt in the polyionic liquid was too high or too low, and the cycle performance of the battery was worse than that of Application Examples 8-9. In Application Examples 14-15, the mass ratio of the polyionic liquid to the ceramic electrolyte was too high or too low, and the cycle performance of the battery was worse than that of the battery in Application Examples 12-13.

[0176] As can be seen from Application Examples 1 and 16 and Comparative Examples 1 and 3, when a battery contains only a ceramic electrolyte film or only a polymer electrolyte film, the cycle performance of the battery is worse than that of a battery that contains both a ceramic electrolyte film and a polymer electrolyte film. The ceramic electrolyte film and the polymer electrolyte film complement each other and can synergistically improve properties such as conductivity, mechanical properties and affinity with the electrode, thereby improving the cycle performance of the battery.

[0177] The polyionic liquid, ceramic electrolyte film and its application provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A polyionic liquid, characterized in that, The polyionic liquid comprises a polymer and a first lithium salt, which are connected by chemical bonds.

2. The polyionic liquid as described in claim 1, characterized in that, In the polyionic liquid, the mass ratio of the polymer to the first lithium salt is (0.02–0.1):(0.04–0.2); and / or In the polyionic liquid, the polymer and the first lithium salt are connected by covalent bonds; and / or The polymer includes one or more of polymer salts and polyesters; and / or The first lithium salt includes organic lithium salts and inorganic lithium salts.

3. The polyionic liquid as described in claim 2, characterized in that, The polymer salt includes polydiallyldimethylammonium chloride; and / or The polyester includes one or more of poly(ethylene glycol) methyl ether acrylate and polyethylene glycol diacrylate; and / or The organolithium salt comprises one or more of lithium trifluoromethanesulfonate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium di(oxalato)borate, and lithium bis(trifluoromethanesulfonyl)imide; and / or The inorganic lithium salt includes one or more of lithium perchlorate, lithium hexafluoroarsenate, lithium tetrafluoroborate, and lithium hexafluorophosphate; and / or The polyionic liquids include lithium polydiallyldimethylammonium chloride-bis(trifluoromethanesulfonyl)imide, lithium polydiallyldimethylammonium chloride-lithium hexafluoroarsenate, lithium polydiallyldimethylammonium chloride-lithium hexafluorophosphate, lithium polydiallyldimethylammonium chloride-lithium bis(oxalato)borate, lithium polydiallyldimethylammonium chloride-lithium trifluoromethanesulfonate, poly(ethylene glycol) methyl ether acrylate-bis(trifluoromethanesulfonyl)imide, and lithium poly(ethylene glycol) methyl ether acrylate-lithium trifluoromethanesulfonate. One or more of the following: (ethylene glycol) methyl ether acrylate-lithium hexafluoroarsenate, poly(ethylene glycol) methyl ether acrylate-lithium bis(fluorosulfonyl)imide, poly(ethylene glycol) methyl ether acrylate-lithium tetrafluoroborate, polyethylene glycol diacrylate-lithium tetrafluoroborate, polyethylene glycol diacrylate-lithium difluorooxalate borate, polyethylene glycol diacrylate-lithium bis(trifluoromethanesulfonyl)imide, polyethylene glycol diacrylate-lithium hexafluoroarsenate, and polyethylene glycol diacrylate-lithium perchlorate.

4. The polyionic liquid as described in claim 1, characterized in that, The polyionic liquid is prepared by the following steps: The polymer and the first lithium salt are provided; The polymer and the first lithium salt are mixed to obtain a polyionic liquid.

5. The polyionic liquid as described in claim 4, characterized in that, The mass ratio of the polymer to the first lithium salt is (0.02–0.1):(0.04–0.2); and / or The step of mixing the polymer and the first lithium salt includes: providing a first solvent, mixing the first solvent with the polymer and the first lithium salt to obtain a polyionic liquid; and / or The polymer and the first lithium salt are mixed at room temperature; and / or The process of mixing the polymer and the first lithium salt further includes a first drying process.

6. The polyionic liquid as described in claim 5, characterized in that, The mass ratio of the polymer to the first lithium salt and the first solvent is (0.06–0.3):(0.12–0.6); and / or The first solvent comprises one or more of N,N-dimethylformamide, acetonitrile, N-methyl-2-pyrrolidone, dimethylacetamide, chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, ethyl acetate, pyrrole, butyric acid, and cresol; and / or The first drying temperature is 60℃~80℃, and the time is 8h~12h.

7. A ceramic electrolyte thin film, characterized in that, The ceramic electrolyte film is made of a composition comprising a ceramic electrolyte and a polyionic liquid as described in any one of claims 1 to 6.

8. The ceramic electrolyte film as described in claim 7, characterized in that, The mass ratio of the ceramic electrolyte to the polyionic liquid is (2.7–10):(0.06–0.3); and / or The ceramic electrolyte includes an oxide solid electrolyte; the oxide solid electrolyte includes one or more of perovskite-type materials, NASICON-type materials, and garnet-type materials; and / or The ceramic electrolyte comprises ceramic electrolyte particles, the average particle size of which is 1 μm to 5 μm; and / or The thickness of the ceramic electrolyte film is 20 μm to 40 μm.

9. The ceramic electrolyte film as described in claim 8, characterized in that, The perovskite-type material includes Li a La b Ti c A d O e Where 0 < a ≤ 0.5, 0 < b < 0.6, 0.9 <c≤1, 0≤d≤0.25, 2<e≤3, A includes one or more of Ba, Sr, and Al, and the perovskite material is Li. 0.5 La 0.5 TiO3, Li 0.29 La 0.57 TiO3, Li 0.30 La 0.57 TiO3, Li 0.33 La 0.56 TiO3, Li 0.34 La 0.51 TiO 2.94 Li 0.30 La 0.567 TiO3, Li 0.36 Sr 0.04 La 0.523 TiO3, Li 0.33 Ba 0.25 La 0.39 TiO3 and (Li 0.33 La 0.56 ) 1.005 Ti 0.99 Al 0.01 One or more of O3; and / or The NASICON-type material includes Li f B g P h O 12 Wherein, 1≤f≤3, 0<g≤4, 1≤h≤3, B includes one or more of Al, Zr, Ti, Ge, and Si, and the NASICON-type material is LiZr2(PO4)3, LiTi2(PO4)3, LiGe2(PO4)3, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li3Zr2Si2PO 12 Li 1.4 Al 0.4 Ti 1.6 (PO4)3, Li 1.4 Ti2Si 0.4 P 2.6 O 12 -AIPO4 and Li 1.5 Al 0.5 Ti 1.5 One or more of (PO4)3; and / or The garnet-type material includes Li i La j Zr k M l O 12 Wherein, 5≤i≤7, 2≤j≤3, 1≤k≤2, 0≤l≤1, and M is selected from any one of Ta, Nb, Hf, Al, Si, Ga, Sc, Ti, V, Y, and Sn. The garnet-type material includes Li7La3Zr2O. 12 Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Li 6.375 La3Zr 1.375 Nb 0.625 O 12 Li 6.85 La 2.9 Ca 0.1 Zr 1.75 Nb 0.25 O 12 Li 5.9 Al 0.2 La3Zr 1.75 W 0.25 O 12 、Li7La 2.75 Ca 0.25 Zr 1.75 Nb 0.25 O 12 and Li 6.4 La3Zr 1.4 Ta 0.6 O 12 One or more of them.

10. The ceramic electrolyte film as described in claim 7, characterized in that, The composition also includes one or more of a second lithium salt and a binder.

11. The ceramic electrolyte film as described in claim 10, characterized in that, The second lithium salt includes one or more of organic lithium salts and inorganic lithium salts; optionally, the organic lithium salt includes one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorooxalateborate, and lithium bis(oxalateborate); optionally, the inorganic lithium salt includes one or more of lithium perchlorate and lithium hexafluorophosphate; and / or The adhesive includes one or more of polyethylene oxide, polyurethane rubber, polyvinylidene fluoride, polyvinylidene fluoride hexafluoropropylene, polyarylene, polycaprolactone, and polyvinyl butyral.

12. The ceramic electrolyte film as described in claim 10, characterized in that, The mass ratio of the ceramic electrolyte to the first lithium salt is (2.7–10):(0.01–0.1); and / or The mass ratio of the ceramic electrolyte to the binder is (2.7-10):(0.5-0.6).

13. The ceramic electrolyte film as described in claim 7, characterized in that, The ceramic electrolyte thin film is prepared by the following steps: Provide the composition; The composition is deposited to obtain a ceramic electrolyte film.

14. The ceramic electrolyte film as described in claim 13, characterized in that, The ceramic electrolyte film is prepared by a wet process, which includes: A second solvent is provided and mixed with the composition to obtain a first mixture; The first mixture is deposited to obtain a ceramic electrolyte film.

15. The ceramic electrolyte film as described in claim 14, characterized in that, The mass ratio of the ceramic electrolyte to the second solvent is (2.7–10):(5–20); and / or The second solvent comprises one or more of N,N-dimethylformamide, acetonitrile, N-methyl-2-pyrrolidone, dimethylacetamide, chlorobenzene, diethylene glycol monobutyl ether, trimethoxybutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, ethyl acetate, pyrrole, butyric acid, and cresol; and / or The mixing of the second solvent and the composition includes: mixing the second solvent and the ceramic electrolyte, and then adding the polyionic liquid to obtain a first mixture.

16. The ceramic electrolyte film as described in claim 15, characterized in that, After the second solvent and the ceramic electrolyte are mixed, a first stirring is performed; and / or The process of adding the polyionic liquid and mixing includes a second stirring; and / or After obtaining the first mixture, and before depositing the first mixture, the process further includes: degassing.

17. The ceramic electrolyte film as described in claim 16, characterized in that, The first stirring speed is 600 r / min to 800 r / min; the time is 5 min to 20 min; and / or the second stirring speed is 800 r / min to 1000 r / min; the time is 5 min to 20 min; and / or The degassing is performed at room temperature; and / or The degassing time is 5 min to 20 min; and / or The degassing includes centrifugal degassing, wherein the centrifugal degassing speed is 1300 r / min to 1500 r / min.

18. An electrochemical device, characterized in that, The electrochemical device includes a ceramic electrolyte membrane as described in any one of claims 8 to 11.

19. The electrochemical device as claimed in claim 18, characterized in that, The electrochemical device includes a battery, the battery including a positive electrode, a negative electrode, and a ceramic electrolyte film located between the positive electrode and the negative electrode.

20. The electrochemical device as claimed in claim 19, characterized in that, The battery includes a composite film, which comprises a ceramic electrolyte film and a polymer electrolyte film. The composite film is located between the positive electrode and the negative electrode, and the ceramic electrolyte film is located between the positive electrode and the polymer electrolyte film.

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