Solid-state electrolyte, battery, and power-using device

Abstract

The application provides a solid-state electrolyte, a battery and a power utilization device, and belongs to the technical field of solid-state electrolyte manufacturing. The solid-state electrolyte comprises an inorganic solid-state electrolyte layer and a polymer solid-state electrolyte layer located on at least one side surface of the inorganic solid-state electrolyte layer, wherein the polymer solid-state electrolyte layer comprises a polyurea polymer and a lithium salt. The solid-state electrolyte is the first to use the polymer solid-state electrolyte composed of the polyurea polymer in combination with the inorganic solid-state electrolyte, so that the solid-state electrolyte has high ionic conductivity and good interface compatibility with the pole piece, thereby making the corresponding battery have excellent specific capacity and cycle performance.

Description

Technical Field

[0001] This application relates to the field of solid electrolyte manufacturing technology, and more specifically, to a solid electrolyte, a battery, and an electrical device. Background Technology

[0002] In the existing technology, solid electrolytes have become a research hotspot due to their advantages such as good safety and high energy density; however, each type of solid electrolyte has its own defects. Specifically, polymer solid electrolytes have the problem of low ionic conductivity, while inorganic solid electrolytes have the problem of poor interfacial compatibility with electrodes. Summary of the Invention

[0003] The purpose of this application is to provide a solid electrolyte, battery, and electrical device, wherein the solid electrolyte is the first to combine polyurea polymer and inorganic solid electrolyte to achieve high ionic conductivity and good interfacial compatibility with the electrode.

[0004] The embodiments of this application are implemented as follows: In a first aspect, embodiments of this application provide a solid electrolyte, including an inorganic solid electrolyte layer and a polymer solid electrolyte layer located on at least one side surface of the inorganic solid electrolyte layer, wherein the polymer solid electrolyte layer includes a polyurea polymer and a lithium salt.

[0005] In the above technical solution, the solid electrolyte is composed of an inorganic solid electrolyte layer and a polymer solid electrolyte layer containing polyurea polymer located on at least one side of the inorganic solid electrolyte layer. The inorganic solid electrolyte layer enables the solid electrolyte to have a high ionic conductivity, while the polymer solid electrolyte layer enables the solid electrolyte to have good interfacial compatibility with the electrode. Through the combined action of the inorganic solid electrolyte layer and the polymer solid electrolyte layer, the solid electrolyte has a high ionic conductivity and good interfacial compatibility with the electrode, thereby enabling the corresponding battery to have excellent specific capacity and cycle performance.

[0006] In some alternative embodiments, the polyurea polymer is obtained by addition reaction of a first compound with polyethylene glycol followed by polycondensation with a second compound; wherein the first compound has the structural formula A, A includes aromatic compounds and / or aliphatic compounds, and isocyanate groups are attached to A; the second compound has the structural formula B, B has quaternary ammonium cations and acid radicals, and amino groups are attached to B.

[0007] In the above technical solution, the second compound has quaternary ammonium cations and acid radicals, meaning that the basic structural unit of the corresponding polyurea polymer also contains quaternary ammonium cations and acid radicals. After the quaternary ammonium cations and acid radicals react with lithium salts, they can provide holes for lithium ions and improve lithium ion mobility by coordinating with anions in the lithium salt. At the same time, the basic structural unit of the polyurea polymer also contains polyethylene oxide units, which also help to improve the ionic conductivity of the polyurea polymer. In addition, the basic structural unit of the polyurea polymer contains a large number of hydrogen bonds and ionic bonds (wherein the ionic bonds originate from quaternary ammonium cations and acid radicals), so that the polyurea polymer has relatively excellent mechanical strength. That is, in addition to being flexible, the polyurea polymer with the above structure also has high ionic conductivity and relatively excellent mechanical strength.

[0008] In some alternative embodiments, the polyurea polymer has the structural formula of Formula I and / or Formula II:

[0009] Formula I;

[0010] Formula II; The polyurea polymer has a molecular weight of 10,000 to 5,000,000, M ranges from 1 to 1,000, n ranges from 1 to 3,000, and i ranges from 1 to 3,000.

[0011] In the above technical solution, the structure of the polyurea polymer is limited to the above range so that the polyurea polymer can maintain suitable flexibility while taking into account both high ionic conductivity and excellent mechanical strength.

[0012] In some alternative implementations, M ranges from 3 to 100, n ranges from 10 to 1000, and i ranges from 10 to 1000.

[0013] In the above technical solution, the structure of the polyurea polymer is further limited to the above range, so that the polyurea polymer can achieve both higher ionic conductivity and better mechanical strength while retaining suitable flexibility.

[0014] In some alternative implementations, the anion is a sulfonate ion.

[0015] In the above technical solution, the acid radical is a sulfonate radical, that is, the second compound is a quaternary ammonium sulfonate inner salt with an amino group attached. In addition to enabling the polyurea polymer to have both high ionic conductivity and excellent mechanical strength, it also has the advantages of low raw material cost and easy large-scale production.

[0016] In some alternative embodiments, the second compound linked to the amino group includes at least one of the following compounds:

[0017] Compound 1;

[0018] Compound 2;

[0019] Compound 3;

[0020] Compound 4;

[0021] Compound 5; In compounds 1 through 5: the structural formula of R1 is C n H 2n+1 And satisfying 1≤n≤10, R2, R3, R4, R5, R6, R7, R8, R9 and R 10 The structural formulas are C n H 2n And it satisfies 1≤n≤10.

[0022] In the above technical solution, the second compound with amino groups adopts the above structure, which enables the polyurea polymer to have both high ionic conductivity and excellent mechanical strength. At the same time, the second compound with amino groups can be applied to a wide variety of specific types, providing a large number of feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0023] In some alternative embodiments, the first compound linked to the isocyanate group includes at least one of the following compounds:

[0024] Compound 6;

[0025] Compound 7;

[0026] Compound 8;

[0027] Compound 9;

[0028] Compound 10;

[0029] Compound 11;

[0030] Compound 12.

[0031] In the above technical solutions, the first compound with isocyanate group is applicable to a wide variety of types and can provide a wide range of feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application; at the same time, the above-mentioned first compounds with isocyanate group also have the advantages of low raw material cost and easy large-scale production.

[0032] In some alternative implementations, the inorganic solid electrolyte layer accounts for 95 wt% to 99.99 wt% of the total mass of the solid electrolyte.

[0033] In the above technical solution, the mass ratio of the inorganic solid electrolyte layer in the solid electrolyte is limited to the above range. That is, the solid electrolyte characteristics are mainly inorganic solid electrolyte and supplemented by polyurea polymer. The inorganic solid electrolyte body makes the solid electrolyte have high ionic conductivity, and the polyurea polymer makes the solid electrolyte and the electrode have excellent interfacial compatibility. Thus, the solid electrolyte has higher ionic conductivity while taking into account its interfacial compatibility with the electrode.

[0034] In some alternative implementations, the thickness of the monolayer polymer solid electrolyte layer is no greater than 5 μm.

[0035] In the above technical solution, the thickness of the single-layer polymer solid electrolyte layer is limited to the above range, so that the solid electrolyte and the electrode have excellent interfacial compatibility, while the corresponding battery has a high energy density.

[0036] In some alternative implementations, the thickness of the monolayer polymer solid electrolyte layer is no greater than 1 μm.

[0037] In the above technical solution, the thickness of the single-layer polymer solid electrolyte layer is limited to the above range, so that the solid electrolyte and the electrode have excellent interfacial compatibility, and the corresponding battery can also have higher energy density.

[0038] In some alternative embodiments, the material of the inorganic solid electrolyte layer includes at least one of the following: sulfur-based inorganic solid electrolyte, perovskite-type inorganic solid electrolyte, Garnet-type inorganic solid electrolyte, NACSION-type inorganic solid electrolyte, Li-Nitride-type inorganic solid electrolyte, Li-Hydride-type inorganic solid electrolyte, Li-halide-type inorganic solid electrolyte, and halogen-based inorganic solid electrolyte.

[0039] In the above technical solutions, the inorganic solid electrolyte layer can be made of a variety of materials, providing a wide range of feasible solutions, which facilitates the promotion and application of the technical solutions provided in the embodiments of this application.

[0040] In some alternative implementations, the lithium salt content in the polymer solid electrolyte layer is 0.1 wt% to 10 wt%.

[0041] In the above technical solution, limiting the mass percentage of lithium salt in the polymer solid electrolyte layer to the above range can effectively improve its ionic conductivity.

[0042] In some alternative implementations, the lithium salt includes LiP(R) f1 R f2 R f3 R f4 R f5 R f6 ), LiB(R) f1 R f2 R f3 R f4 LiN(SO2R) f1 (SO2R) f2 LiC(SO2R) f1 (SO2R) f2 (SO2R) f3 At least one of lithium difluorooxalate borate, lithium dioxalate borate, lithium perchlorate, and lithium hexafluoroarsenate, wherein R f1 R f2 R f3 R f4 R f5 and R f6 C n F 2n+1 And it satisfies 0 < n ≤ 10.

[0043] In the above technical solutions, lithium salts are applicable to a wide variety of materials, providing a large number of feasible implementation schemes, which facilitates the promotion and application of the technical solutions provided in the embodiments of this application.

[0044] Secondly, embodiments of this application provide a battery, which includes a positive electrode, a solid electrolyte layer, and a negative electrode stacked sequentially; wherein the solid electrolyte layer is the solid electrolyte provided in the first aspect embodiment.

[0045] In the above technical solution, the solid electrolyte layer in the battery is the solid electrolyte provided in the first aspect embodiment. Since the solid electrolyte has high ionic conductivity and excellent interfacial compatibility with the electrode, the battery has excellent specific capacity and cycle performance.

[0046] In some alternative embodiments, the thickness of the positive electrode active layer in the positive electrode sheet is 10 nm to 100 μm, or / and the thickness of the solid electrolyte layer is 10 nm to 100 μm, or / and the thickness of the negative electrode active layer in the negative electrode sheet is 10 nm to 100 μm.

[0047] In the above technical solution, the thicknesses of the positive electrode, solid electrolyte layer and negative electrode are limited to the above range, which can be well compatible with various commonly used battery specifications.

[0048] Thirdly, embodiments of this application provide an electrical device, including the battery provided in the second aspect of the embodiment. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0050] It should be noted that the terms "and / or" in this application, such as "feature 1 and / or feature 2", all refer to the three cases of "feature 1" alone, "feature 2" alone, and "feature 1" plus "feature 2".

[0051] In addition, in the description of this application, unless otherwise stated, "one or more" means two or more; the range of "numerical value a to numerical value b" includes the two endpoints "a" and "b"; and "unit of measurement" in "numerical value a to numerical value b + unit of measurement" represents the "unit of measurement" of both "numerical value a" and "numerical value b".

[0052] The following is a detailed description of a solid electrolyte, battery, and electrical device according to an embodiment of this application.

[0053] In a first aspect, embodiments of this application provide a solid electrolyte, including an inorganic solid electrolyte layer and a polymer solid electrolyte layer located on at least one side surface of the inorganic solid electrolyte layer, wherein the polymer solid electrolyte layer includes a polyurea polymer and a lithium salt.

[0054] In this application, the solid electrolyte is composed of an inorganic solid electrolyte layer and a polymer solid electrolyte layer containing a polyurea polymer located on at least one side of the inorganic solid electrolyte layer. The inorganic solid electrolyte layer enables the solid electrolyte to have a high ionic conductivity, while the polymer solid electrolyte layer enables the solid electrolyte to have good interfacial compatibility with the electrode. Through the combined action of the inorganic solid electrolyte layer and the polymer solid electrolyte layer, the solid electrolyte has a high ionic conductivity and good interfacial compatibility with the electrode, thereby enabling the corresponding battery to have superior specific capacity and cycle performance.

[0055] As an example, the polyurea polymer is obtained by addition reaction of a first compound with oligoethylene glycol followed by polycondensation with a second compound; wherein the first compound has the structural formula A, A includes aromatic compounds and / or aliphatic compounds, and isocyanate groups are attached to A; the second compound has the structural formula B, B has quaternary ammonium cations and acid radicals, and amino groups are attached to B.

[0056] In this embodiment, the second compound contains quaternary ammonium cations and acid radicals, meaning that the basic structural unit of the corresponding polyurea polymer contains quaternary ammonium cations and acid radicals. After interacting with lithium salts, the quaternary ammonium cations and acid radicals can provide holes for lithium ions and enhance lithium ion mobility by coordinating with anions in the lithium salts. At the same time, the basic structural unit of the polyurea polymer also contains polyethylene oxide units, which also help to improve the ionic conductivity of the polyurea polymer. In addition, the basic structural unit of the polyurea polymer contains a large number of hydrogen bonds and ionic bonds (wherein the ionic bonds originate from quaternary ammonium cations and acid radicals), so that the polyurea polymer has relatively excellent mechanical strength. That is, in addition to being flexible, the polyurea polymer with the above structure also has high ionic conductivity and relatively excellent mechanical strength.

[0057] As an example, the structural formula of polyurea polymers is Formula I or / and Formula II:

[0058] Formula I;

[0059] Formula II; Wherein, the molecular weight of the polyurea polymer is 10,000 to 5,000,000 (e.g., but not limited to any one of the molecular weights of 10,000, 50,000, 100,000, 500,000, 1,000,000, 2,000,000, 3,000,000, 4,000,000, and 5,000,000, or any range between two), and the value of M is in the range of 1 to 1,000 (e.g., but not limited to M being any one of the molecular weights of 1, 10, 50, 100, 200, 400, 600, 800, and 1,000, or any range between two), and n The value of n is in the range of 1 to 3000 (for example, but not limited to n being any one of the values ​​of 1, 10, 50, 100, 500, 1000, 1500, 2000, 2500 and 3000 or any range between two values), and the value of i is in the range of 1 to 3000 (for example, but not limited to i being any one of the values ​​of 1, 10, 50, 100, 500, 1000, 1500, 2000, 2500 and 3000 or any range between two values).

[0060] In this embodiment, the structure of the polyurea polymer is limited to the above-mentioned range so that the polyurea polymer can maintain suitable flexibility while also achieving high ionic conductivity and excellent mechanical strength.

[0061] As an example, M takes values ​​from 3 to 100 (e.g., but not limited to M taking any one of the values ​​of 3, 10, 20, 40, 60, 80, and 100, or any range between any two), n takes values ​​from 10 to 1000 (e.g., but not limited to n taking any one of the values ​​of 1, 10, 50, 100, 200, 400, 600, 800, and 1000, or any range between any two), and i takes values ​​from 10 to 1000 (e.g., but not limited to n taking any one of the values ​​of 1, 10, 50, 100, 200, 400, 600, 800, and 1000, or any range between any two).

[0062] In this embodiment, the structure of the polyurea polymer is further limited to the above-mentioned range so that the polyurea polymer can achieve both higher ionic conductivity and better mechanical strength while retaining suitable flexibility.

[0063] As an example, the acid radical is the sulfonate radical.

[0064] In this embodiment, the acid radical is a sulfonate radical, that is, the second compound is a quaternary ammonium sulfonate inner salt with an amino group attached. In addition to enabling the polyurea polymer to have both high ionic conductivity and excellent mechanical strength, it also has the advantages of low raw material cost and easy large-scale production.

[0065] As an example, the second compound connected to an amino group includes at least one of the following compounds:

[0066] Compound 1;

[0067] Compound 2;

[0068] Compound 3;

[0069] Compound 4;

[0070] Compound 5; In compounds 1 through 5: the structural formula of R1 is C n H 2n+1 And satisfying 1≤n≤10, R2, R3, R4, R5, R6, R7, R8, R9 and R 10 The structural formulas are C n H 2n And it satisfies 1≤n≤10.

[0071] In this embodiment, the second compound with amino groups adopts the above-described structure, which enables the polyurea polymer to possess both high ionic conductivity and excellent mechanical strength. At the same time, the second compound with amino groups can be applied to a wide variety of specific types, providing a large number of feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0072] In other possible embodiments, the acid radical ion may also be a phosphate radical ion, that is, the second compound with an amino group is a quaternary ammonium phosphate inner salt with an amino group.

[0073] As an example, the first compound connected to the isocyanate group includes at least one of the following compounds:

[0074] Compound 6;

[0075] Compound 7;

[0076] Compound 8;

[0077] Compound 9;

[0078] Compound 10;

[0079] Compound 11;

[0080] Compound 12.

[0081] In this embodiment, the first compound with isocyanate group is applicable to a wide variety of types, providing more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application; at the same time, the above-mentioned first compounds with isocyanate group also have the advantages of low raw material cost and easy large-scale production.

[0082] As an example, in a solid electrolyte, the inorganic solid electrolyte layer accounts for 95 wt% to 99.99 wt% by mass, such as, but not limited to, any one of 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, and 99.99 wt% by mass, or a range between any two.

[0083] In this embodiment, the mass ratio of the inorganic solid electrolyte layer in the solid electrolyte is limited to the above-mentioned range. That is, the solid electrolyte is characterized by being mainly composed of inorganic solid electrolyte and supplemented by polyurea polymer. The inorganic solid electrolyte as the main component gives the solid electrolyte a high ionic conductivity, and the polyurea polymer gives the solid electrolyte and the electrode a better interfacial compatibility. Thus, the solid electrolyte has a higher ionic conductivity while taking into account its interfacial compatibility with the electrode.

[0084] As an example, the thickness of the monolayer polymer solid electrolyte layer is no greater than 5 μm, for example, but not limited to any one of 1 μm, 2 μm, 3 μm, 4 μm and 5 μm or any range between two of them.

[0085] In this embodiment, the thickness of the single-layer polymer solid electrolyte layer is limited to the above range so that the solid electrolyte and the electrode have excellent interfacial compatibility, while the corresponding battery has a high energy density (too thick a solid electrolyte layer will reduce the energy density of the battery).

[0086] As an example, the thickness of the monolayer polymer solid electrolyte layer is no greater than 1 μm, for example, but not limited to any one of 0.1 μm, 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm and 1.0 μm or any range between two of them.

[0087] In this embodiment, the thickness of the single-layer polymer solid electrolyte layer is limited to the above-mentioned range, so that the solid electrolyte and the electrode have excellent interfacial compatibility, and the corresponding battery can also have a higher energy density.

[0088] As an example, the material of the inorganic solid electrolyte layer includes at least one of the following: sulfide-based inorganic solid electrolyte, perovskite-type inorganic solid electrolyte, Garnet-type inorganic solid electrolyte, NACSION-type inorganic solid electrolyte, Li-Nitride-type inorganic solid electrolyte, Li-Hydride-type inorganic solid electrolyte, Li-halide-type inorganic solid electrolyte, and halogen-based inorganic solid electrolyte.

[0089] In this embodiment, the inorganic solid electrolyte layer can be made of a variety of materials, providing a wide range of feasible solutions, which facilitates the promotion and application of the technical solutions provided in this application.

[0090] As an example, the sulfide-based inorganic solid electrolyte is selected from Li3PS4, Li 9.6 P3S 12 Li7P3S 11 Li 11 Si2PS 12 Li 10 SiP2S 12 Li 10 SnP2S 12 Li 10 GeP2S 12 Li 10 Si 0.5 Ge 0.5 P2S 12 Li 10 Ge 0.5 Sn 0.5 P2S 12 Li 10 Si 0.5 Sn 0.5 P2S 12 Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 At least one of Li6PS5Cl, Li6PS5Br, Li7PS6 and Li7PS5I.

[0091] As an example, Garnet-type inorganic solid electrolytes are selected from Li7La3Zr2O 12Li 6.5 La3Zr 1.5 Ta 0.5 O 12 .

[0092] As an example, NASCION-type inorganic solid electrolytes are selected from Li 1.3 Al 0 .3 Ti 1.7 (PO4)3.

[0093] As an example, Li-Nitride-type inorganic solid electrolytes are selected from at least one of Li3N, Li7PN4, LiSi2N3 and LiPN2.

[0094] As an example, Li-Hydride inorganic solid electrolytes are selected from at least one of Li2NH, LiNH2, Li3(NH2)2I, LiBH4 and LiAlH4.

[0095] As an example, the Li-halide-type inorganic solid-state electrolyzer is selected from at least one of Li2CdCl4, Li2MgCl4 and Li2ZnCl4.

[0096] As an example, the general formula of halogen-based inorganic solid electrolytes is Li3M1X6 (where M1 is selected from at least one of Y, In, Er, Zr, Yb, Ti, Hf, Ho, Sc and Ta, and X is selected from at least one of F, Cl, Br and I).

[0097] As an example, the halogen solid electrolyte is selected from at least one of Li3YCl6, Li3InCl6, Li3ErCl6, Li3YbCl6, Li3TiCl6, Li3ZrCl6, Li3HfCl6, Li3HoCl6, Li3ScCl6 and LiTaCl6.

[0098] As an example, in the polymer solid electrolyte layer, the mass percentage of lithium salt is 0.1wt% to 10wt%, for example, but not limited to any one of the mass percentages of 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, and 10wt%, or any range between two of them.

[0099] In this embodiment, limiting the mass percentage of lithium salt in the polymer solid electrolyte layer to the above-mentioned range can effectively improve its ionic conductivity.

[0100] As an example, the lithium salt is selected from LiP(R) f1 R f2 R f3 Rf4 R f5 R f6 ), LiB(R) f1 R f2 R f3 R f4 LiN(SO2R) f1 (SO2R) f2 LiC(SO2R) f1 (SO2R) f2 (SO2R) f3 At least one of lithium difluorooxalate borate, lithium dioxalate borate, lithium perchlorate, and lithium hexafluoroarsenate, wherein R f1 R f2 R f3 R f4 R f5 and R f6 C n F 2n+1 And it satisfies 0 < n ≤ 10.

[0101] In this embodiment, lithium salts are applicable to a wide variety of materials, providing more feasible implementation schemes, thereby facilitating the promotion and application of the technical solutions provided in the embodiments of this application.

[0102] As an example, the lithium salt is selected from at least one of LiPF6, LiBF4, LiTFSI, LiFSI, LiDFOB, LiBOB, LiClO4 and LiAsF6.

[0103] In this embodiment, the lithium salts described above are better compatible with polyurea polymers.

[0104] It should be noted that structural units in composite solid electrolytes that are not specifically described or limited can be selected and configured in accordance with conventional methods in the field.

[0105] It should be noted that the preparation method of polyurea polymer can be carried out according to conventional processes in the field. For example, the system after the addition of a first compound with isocyanate groups and polyethylene glycol can be used as the first raw material, and the system after mixing a second compound with amino groups and lithium salt can be used as the second raw material. Then, the first and second raw materials are simultaneously applied to the target surface by chemical vapor deposition, physical vapor deposition or pneumatic spraying technology to carry out in-situ polymerization to obtain polyurea polymer.

[0106] Secondly, embodiments of this application provide a battery, which includes a positive electrode, a solid electrolyte layer, and a negative electrode stacked sequentially; wherein the solid electrolyte layer is the solid electrolyte provided in the first aspect embodiment.

[0107] In this application, the solid electrolyte layer in the battery is the solid electrolyte provided in the first aspect embodiment. Since the solid electrolyte has high ionic conductivity and excellent interfacial compatibility with the electrode, the battery has excellent specific capacity and cycle performance.

[0108] As an example, the thickness of the positive electrode active layer in the positive electrode sheet is 10 nm to 100 μm (e.g., but not limited to any one of 10 nm, 50 nm, 100 nm, 500 nm, 1 μm, 10 μm, 50 μm and 100 μm or any range between any two), and / or the thickness of the solid electrolyte layer is 10 nm to 100 μm (e.g., but not limited to any one of 10 nm, 50 nm, 100 nm, 500 nm, 1 μm, 10 μm, 50 μm and 100 μm or any range between any two), and / or the thickness of the negative electrode active layer in the negative electrode sheet is 10 nm to 100 μm (e.g., but not limited to any one of 10 nm, 50 nm, 100 nm, 500 nm, 1 μm, 10 μm, 50 μm and 100 μm or any range between any two).

[0109] In this embodiment, the thicknesses of the positive electrode, the solid electrolyte layer, and the negative electrode are limited to the above-mentioned ranges, which can better accommodate various commonly used battery specifications.

[0110] As an example, the positive electrode sheet includes a positive current collector and a positive active layer located on the surface of the positive current collector, wherein the positive current collector includes aluminum foil.

[0111] As an example, the positive electrode active layer comprises, by weight percentage, 70wt% to 99wt% positive electrode active material, 0.5wt% to 5wt% conductive agent, 0.5wt% to 25wt% solid electrolyte and 0wt% to 5wt% binder.

[0112] As an example, the positive electrode active material is selected from at least one of carbon-coated LiM2PO4 (wherein M2 is selected from at least one of Fe, Co, Ni and Mn) and LiM3O2 (wherein M3 is selected from at least one of Ni, Co, Mn and Al).

[0113] As an example, the average particle size of the positive electrode active material is 100 nm to 50 μm.

[0114] As an example, in the positive electrode active layer, the conductive agent includes at least one of carbon black, acetylene black, and carbon nanotubes.

[0115] As an example, in the positive electrode active layer, the average particle size of the conductive agent is 100 nm to 50 μm.

[0116] It should be noted that there are no restrictions on the type of solid electrolyte, and adjustments can be made according to the material of the solid electrolyte layer.

[0117] As an example, in the positive electrode active layer, the binder includes at least one of polyvinylidene fluoride and polyhexafluoropropylene polymers.

[0118] As an example, in the positive electrode active layer, the molecular weight of the binder ranges from 100,000 to 5 million.

[0119] As an example, the negative electrode sheet includes a negative current collector and a negative active layer located on the surface of the negative current collector, wherein the negative current collector includes copper foil.

[0120] In other possible implementations, the negative electrode can also be a lithium metal foil or a copper-lithium composite metal foil.

[0121] As an example, the negative electrode active layer comprises, by weight percentage, 70wt% to 99wt% negative electrode active material, 0.5wt% to 5wt% conductive agent, 0.5wt% to 25wt% solid electrolyte and 0wt% to 5wt% binder.

[0122] As an example, the negative electrode active material includes at least one of lithium powder, graphite, silicon, and silicon-carbon.

[0123] As an example, the average particle size of the negative electrode active material is 100 nm to 50 μm.

[0124] As an example, in the negative electrode active layer, the conductive agent includes at least one of carbon black, acetylene black, and carbon nanotubes.

[0125] As an example, in the negative electrode active layer, the average particle size of the conductive agent is 100 nm to 50 μm.

[0126] It should be noted that there are no restrictions on the type of solid electrolyte, and adjustments can be made according to the material of the solid electrolyte layer.

[0127] As an example, in the negative electrode active layer, the binder includes at least one of styrene-butadiene rubber, nitrile rubber, and polyisobutylene.

[0128] As an example, in the negative electrode active layer, the molecular weight of the binder ranges from 100,000 to 5 million.

[0129] It should be noted that functional units in the battery that are not specifically described or limited can be set in accordance with the conventional selection in this field.

[0130] It should be noted that since polyurea polymers can be directly prepared through in-situ deposition, the preparation method of the polyurea polymer solid electrolyte layer in the solid electrolyte layer is quite flexible and can be adapted to actual needs.

[0131] In some possible implementations, a polyurea polymer solid electrolyte layer may be deposited in situ on the surface of the electrode using chemical vapor deposition and / or pneumatic spraying technology. Then, the electrode with the polymer solid electrolyte layer and the inorganic solid electrolyte layer are laminated to make the solid electrolyte layer in the final battery a composite of the inorganic solid electrolyte layer and the polymer solid electrolyte layer.

[0132] In some possible implementations, a polyurea polymer solid electrolyte layer can be formed by directly depositing it in situ on the surface of the inorganic solid electrolyte layer using chemical vapor deposition and / or pneumatic spraying techniques, so that the solid electrolyte layer in the final battery is a composite of an inorganic solid electrolyte layer and a polymer solid electrolyte layer.

[0133] In some possible implementations, a polyurea polymer solid electrolyte layer of a predetermined thickness may be first deposited in situ on the surface of the electrode using chemical vapor deposition and / or pneumatic spraying technology. Simultaneously, a polyurea polymer solid electrolyte layer of a predetermined thickness may be deposited in situ on the surface of the inorganic solid electrolyte layer using chemical vapor deposition and / or pneumatic spraying technology. Then, the electrode with the polymer solid electrolyte layer and the inorganic solid electrolyte layer are laminated to make the solid electrolyte layer in the final battery a composite of the inorganic solid electrolyte layer and the polymer solid electrolyte layer.

[0134] It should be noted that chemical vapor deposition (CVD) and aero-spraying technology each have their own advantages and disadvantages (specifically, the polymer solid electrolyte layer formed by CVD can extend into the pore structure of the electrode, thereby providing an additional continuous transport channel for lithium-ion transport, which helps to improve the specific capacity and cycle performance of the battery; aero-spraying technology has the advantages of low cost and ease of large-scale mass production). In order to make the prepared polymer solid electrolyte layer have better performance and low cost, in the process of preparing polyurea polymer solid electrolyte, a thin layer of polyurea polymer solid electrolyte substrate can be prepared first using CVD, and then the substrate can be thickened using aero-spraying technology until the preset thickness is reached.

[0135] At the same time, it should be emphasized that because polyurea polymers can be formed by in-situ deposition, they can achieve an ultra-thin effect (e.g., thickness not exceeding 1 μm) when used in combination with inorganic solid electrolyte layers. This improves the interfacial compatibility between the electrode and the solid electrolyte layer without significantly increasing the thickness of the solid electrolyte layer, resulting in a battery with superior energy density.

[0136] It should be noted that the specific process for preparing the polyurea polymer solid electrolyte layer using chemical vapor deposition and pneumatic spraying techniques is not limited and can be carried out according to conventional processes in this field.

[0137] It should be noted that the preparation process of the inorganic solid electrolyte layer is not limited and can be carried out according to the specific material type and conventional processes in this field.

[0138] Thirdly, embodiments of this application provide an electrical device, including the battery provided in the second aspect of the embodiment.

[0139] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0140] Example 1 This application provides a method for preparing a battery, including the following steps: Synthesis of compound S10: First, according to reaction formula (1), 316.70g of 1,4,7-tris(2-chloroethyl)-triazacyclononane and 318.42g of 1,3-propanesulfonic acid lactone were reacted at 70℃ for 48h, and then recrystallized with anhydrous ethanol to obtain intermediate 5; then, according to reaction formula (2), intermediate 5 was ammonolyzed with excess ammonia to obtain the final compound 5.

[0141] Reaction formula (1) ; Reaction formula (2) Preparation of S20 SPEs-positive electrode: 96.7g of ternary positive electrode material NCM, 1.1g of conductive agent, and 2.2g of binder PVDF were uniformly dispersed in 40g of N-methylpyrrolidone and coated on both sides of a 12μm thick aluminum foil. After drying, the positive electrode was rolled to a single active layer thickness of 92μm, cut to a certain size, and placed in a vapor deposition apparatus. 168.19g of compound 7 and 200g of polyethylene glycol (weight average molecular weight 200g / mol) were mixed at room temperature for 6h to form reaction solution 1. 71.77g of LiTFSI and 528.76g of compound 5 were mixed at room temperature for 2h to form reaction solution 2. Reaction solutions 1 and 2 were deposited on both sides of the positive electrode using vapor deposition technology to obtain SPEs-positive electrode (i.e., a positive electrode with a polyurea polymer solid electrolyte layer on the surface), wherein the thickness of the deposited single polymer solid electrolyte layer is 100nm.

[0142] Preparation of S30 negative electrode: Take 92g of graphite negative electrode material, 5g of sulfide solid electrolyte Li6PS5Cl, 1.1g of conductive agent, and 1.9g of binder nitrile rubber (NBR). Then, disperse them evenly through a dry process and coat them on both sides of an 8μm thick copper foil. Roll the coating until the active layer has a single layer thickness of 134μm. Cut the coating to the size that matches the positive electrode.

[0143] Preparation of S40 inorganic solid electrolyte layer: 5g of sulfide solid electrolyte Li6PS5Cl was ultrasonically dispersed into 100mL of anhydrous tetrahydrofuran, and then sprayed onto both sides of 15μm thick PET nonwoven fabric using a pneumatic spraying device; after drying, it was cut into the preset size.

[0144] Preparation of S50 all-solid-state battery: The prepared negative electrode sheet and two inorganic solid electrolyte layers (with the negative electrode sheet in the middle) are pressed under 200 MPa pressure for 2 hours using an isostatic press to obtain a negative electrode sheet-inorganic solid electrolyte composite. Then, the processed negative electrode sheet-inorganic solid electrolyte composite is alternately stacked with a positive electrode sheet and hot-pressed at 80°C and 2 MPa pressure to obtain a solid-state battery.

[0145] Example 2 This application provides a method for preparing a battery, which differs from Example 1 only in that: Preparation of S20 SPEs-positive electrode: 96.7g of ternary positive electrode material NCM, 1.1g of conductive agent, and 2.2g of binder PVDF were uniformly dispersed in 40g of N-methylpyrrolidone and coated on both sides of a 12μm thick aluminum foil. After drying, the positive electrode was rolled to a single-sided active layer thickness of 92μm, cut to a certain size, and placed in a vapor deposition apparatus. 168.19g of compound 7 and 200g of polyethylene glycol (weight average molecular weight 200g / mol) were mixed at room temperature for 6h to form reaction solution 1. 71.77g of LiTFSI and 528.76g of compound 5 were mixed at room temperature for 2h to form reaction solution 2. Reaction solutions 1 and 2 were deposited on both sides of the positive electrode using vapor deposition technology to obtain the SPEs-positive electrode, wherein the thickness of the deposited monolayer polymer solid electrolyte layer is 100nm.

[0146] Preparation of S30 SPEs-Anode Sheets: 96g of graphite anode material, 1.1g of conductive agent, 1.4g of dispersant CMC, and 1.5g of binder SBR were taken, dispersed evenly in 80g of water, and coated on both sides of an 8μm thick copper foil. After drying, the anode sheet was rolled to a single-sided active layer thickness of 127μm, cut to a certain size, and placed in a vapor deposition apparatus. 168.19g of compound 7 and 200g of polyethylene glycol (weight average molecular weight 200g / mol) were mixed at room temperature for 6h to form reaction solution 1, and 71.77g of LiTFSI and 528.76g of compound 5 were mixed at room temperature for 2h to form reaction solution 2. Reaction solutions 1 and 2 were deposited on both sides of the anode sheet using vapor deposition technology to obtain SPEs-anode sheets, wherein the thickness of the deposited monolayer polymer solid electrolyte layer is 100nm.

[0147] Preparation of S40 inorganic solid electrolyte layer: Take 10g of solid electrolyte LATP powder with a particle size of 200nm (chemical formula: Li 1.3 Al 0.3 Ti 1.7 (PO4)3) is dispersed in an ethanol solution of polyvinyl butyral (10 wt%), and then cast onto both sides of a 100 μm thick release film using a casting machine; after drying, it is cut into a certain size and sintered in a muffle furnace, and then the inorganic solid electrolyte layer is peeled off from the release film.

[0148] Preparation of S50 all-solid-state battery: Reaction liquid 1 and reaction liquid 2 were sprayed onto the surfaces of the prepared SPEs-positive and SPEs-negative electrode sheets using pneumatic spraying technology, respectively, with the polymer thickness of the single-sided spraying controlled at 1 μm. Then, the treated positive electrode sheet, inorganic solid electrolyte layer and negative electrode sheet were stacked alternately, and then hot-pressed at 80°C and 2 MPa pressure to obtain the solid-state battery.

[0149] Example 3 This application provides a method for preparing a battery, which differs from Example 2 only in that: in S40, 10g of solid electrolyte LLZTO powder with a particle size of 200nm (chemical formula: Li) is taken. 6.5 La3Zr 1.5 Ta 0.5 O 12 The mixture is dispersed in an ethanol solution of polyvinyl butyral (10 wt%), and then cast onto both sides of a 100 μm thick release film using a casting machine. After drying, it is cut into a certain size and sintered in a muffle furnace. Then, the inorganic solid electrolyte layer is peeled off from the release film.

[0150] Example 4 This application provides a method for preparing a battery, which differs from Example 1 only in that: S20 Preparation of positive electrode sheet: 90g of ternary positive electrode material NCM, 3g of conductive agent and 2g of binder PTFE are taken, dispersed evenly by dry process and then coated on 12μm thick aluminum foil and rolled to the active layer with a single-sided thickness of 92μm. After being cut to a certain size, it is pressed into shape by isostatic pressing under a pressure of 200MPa.

[0151] Preparation of S30 SPEs-Anode Sheet: 96g of graphite anode material, 1.1g of conductive agent, 1.4g of dispersant CMC, and 1.5g of binder SBR were taken, dispersed evenly in 80g of water, and coated onto an 8μm thick copper foil. After drying, the anode sheet was rolled to a single-sided active layer thickness of 127μm, cut to a certain size, and placed in a chemical vapor deposition (CVD) apparatus. 168.19g of compound 7 and 200g of polyethylene glycol (weight average molecular weight 200g / mol) were mixed at room temperature for 6 hours to form reaction solution 1. 71.77g of LiTFSI and 528.76g of compound 5 were mixed at room temperature for 2 hours to form reaction solution 2. Reaction solutions 1 and 2 were deposited onto the surface of the anode sheet using chemical vapor deposition (CVD) technology to obtain the SPEs-anode sheet, wherein the thickness of the deposited monolayer polymer solid electrolyte layer is 100nm.

[0152] Preparation of S40 inorganic solid electrolyte layer: 5 g of halide solid electrolyte Li3YCl6 was ultrasonically dispersed into 100 mL of anhydrous tetrahydrofuran, and then sprayed onto both sides of 15 μm thick PET nonwoven fabric using a pneumatic spraying device; after drying, it was cut into the preset size.

[0153] Preparation of S50 all-solid-state battery: The prepared SPEs-negative electrode sheet was sprayed with reaction solution 1 and reaction solution 2 onto both sides of the electrode sheet using a pneumatic sprayer, with the polymer thickness of the single-sided spraying controlled at 1 μm. Then, the treated positive electrode sheet, inorganic solid electrolyte layer and positive electrode sheet were stacked alternately, and then hot-pressed at 80℃ and 2MPa pressure to obtain the battery.

[0154] Example 5 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 6.

[0155] Example 6 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 6.

[0156] Example 7 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 6.

[0157] Example 8 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 6.

[0158] Example 9 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 8.

[0159] Example 10 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 8.

[0160] Example 11 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 8.

[0161] Example 12 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 8.

[0162] Example 13 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 9.

[0163] Example 14 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 9.

[0164] Example 15 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 9.

[0165] Example 16 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 9.

[0166] Example 17 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 10.

[0167] Example 18 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 10.

[0168] Example 19 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 10.

[0169] Example 20 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 10.

[0170] Example 21 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 11.

[0171] Example 22 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 11.

[0172] Example 23 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 11.

[0173] Example 24 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 11.

[0174] Example 25 This application provides a method for preparing an all-solid-state battery, which differs from Example 1 only in that the first compound is compound 12.

[0175] Example 26 This application provides a method for preparing an all-solid-state battery, which differs from Example 2 only in that the first compound is compound 12.

[0176] Example 27 This application provides a method for preparing an all-solid-state battery, which differs from Example 3 only in that the first compound is compound 12.

[0177] Example 28 This application provides a method for preparing an all-solid-state battery, which differs from Example 4 only in that the first compound is compound 12.

[0178] Comparative Example 1 This application provides a comparative method for preparing a battery, which differs from Example 1 only in that: the solid electrolyte layer is composed only of an inorganic solid electrolyte layer and neither the positive electrode nor the negative electrode has a polyurea polymer layer on its surface.

[0179] Comparative Example 2 This application provides a comparative example of a method for preparing a battery, which differs from Example 2 only in that: the solid electrolyte layer is composed only of an inorganic solid electrolyte layer and neither the positive electrode nor the negative electrode has a polyurea polymer layer on its surface.

[0180] Comparative Example 3 This application provides a comparative example of a method for preparing a battery, which differs from Example 3 only in that: the solid electrolyte layer is composed only of an inorganic solid electrolyte layer and neither the positive electrode nor the negative electrode has a polyurea polymer layer on its surface.

[0181] Comparative Example 4 This application provides a comparative example of a method for preparing a battery, which differs from Example 4 only in that: the solid electrolyte layer consists only of an inorganic solid electrolyte layer and neither the positive electrode nor the negative electrode has a polyurea polymer layer on its surface.

[0182] Test case Battery electrical performance testing Test method: The batteries prepared in Examples 1-28 and Comparative Examples 1-4 were used as samples. The discharge specific capacity and cycle performance of each sample were then tested, and the test results are summarized in Table 1.

[0183] The test steps for discharge specific capacity are as follows: Each solid-state battery was kept at 25°C for 5 hours. Then, it was charged at a constant current of 0.5C to 4.25V, left to stand for 5 minutes, and then charged at a constant voltage of 4.25V to 0.05C. Finally, it was discharged at a rate of 0.5C to 2.5V and left to stand for 5 minutes. The initial charge capacity and discharge capacity were recorded, and the discharge specific capacity was calculated from these.

[0184] The test steps for cycle performance are as follows: Each solid-state battery was kept at 25°C for 5 hours. Then, it was charged at a constant current of 0.5C to 4.25V, left to stand for 5 minutes, and then charged at a constant voltage of 4.25V to 0.05C. Finally, it was discharged at a rate of 0.5C to 2.5V and left to stand for 5 minutes. This cycle was repeated 100 times. The charging and discharging capacities of the 100th cycle were recorded, and the specific discharge capacity was calculated from these values.

[0185] Table 1

[0186] Referring to Table 1, the test results of Examples 1-28 and Comparative Examples 1-4 show that the solid electrolyte layer is composed of both an inorganic solid electrolyte layer and a polyurea polymer layer. Compared with batteries containing only one component, the former has superior specific capacity and cycle performance.

[0187] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A solid electrolyte, characterized in that, It includes an inorganic solid electrolyte layer and a polymer solid electrolyte layer located on at least one side surface of the inorganic solid electrolyte layer, wherein the polymer solid electrolyte layer includes a polyurea polymer and a lithium salt.

2. The solid electrolyte according to claim 1, characterized in that, The polyurea polymer is obtained by addition reaction of a first compound with polyethylene glycol followed by polycondensation with a second compound; wherein the first compound has the structural formula A, A includes aromatic compounds and / or aliphatic compounds, and isocyanate groups are attached to A; the second compound has the structural formula B, B has quaternary ammonium cations and acid radicals, and amino groups are attached to B.

3. The solid electrolyte according to claim 2, characterized in that, The polyurea polymer has the structural formula of Formula I and / or Formula II: Formula I; Formula II; Wherein, the molecular weight of the polyurea polymer is 10,000 to 5,000,000, the value of M is 1 to 1,000, the value of n is 1 to 3,000, and the value of i is 1 to 3,000. Optionally, the value of M ranges from 3 to 100, the value of n ranges from 10 to 1000, and the value of i ranges from 10 to 1000.

4. The solid electrolyte according to claim 2, characterized in that, The acid radical ion is a sulfonate ion.

5. The solid electrolyte according to claim 4, characterized in that, The second compound, which is attached to an amino group, includes at least one of the following compounds: Compound 1; Compound 2; Compound 3; Compound 4; Compound 5; In compounds 1 through 5: the structural formula of R1 is C n H 2n+1 And satisfying 1≤n≤10, R2, R3, R4, R5, R6, R7, R8, R9 and R 10 The structural formulas are C n H 2n And it satisfies 1≤n≤10.

6. The solid electrolyte according to any one of claims 1 to 5, characterized in that, The first compound with an isocyanate group attached includes at least one of the following compounds: Compound 6; Compound 7; Compound 8; Compound 9; Compound 10; Compound 11; Compound 12.

7. The solid electrolyte according to any one of claims 1 to 5, characterized in that, In the solid electrolyte, the inorganic solid electrolyte layer accounts for 95wt%~99.99wt% by mass; Or / and, the thickness of a single polymer solid electrolyte layer is not greater than 5 μm; Optionally, the thickness of a single polymer solid electrolyte layer is no greater than 1 μm.

8. The solid electrolyte according to any one of claims 1 to 5, characterized in that, The inorganic solid electrolyte layer is made of at least one of the following: sulfur-based inorganic solid electrolyte, Perovskite-type inorganic solid electrolyte, Garnet-type inorganic solid electrolyte, NACSION-type inorganic solid electrolyte, Li-Nitride-type inorganic solid electrolyte, Li-Hydride-type inorganic solid electrolyte, Li-halide-type inorganic solid electrolyte, and halogen-based inorganic solid electrolyte.

9. The solid electrolyte according to any one of claims 1 to 5, characterized in that, In the polymer solid electrolyte layer, the lithium salt accounts for 0.1 wt% to 10 wt% by mass. The lithium salt includes LiP(R) f1 R f2 R f3 R f4 R f5 R f6 ), LiB(R) f1 R f2 R f3 R f4 LiN(SO2R) f1 (SO2R) f2 LiC(SO2R) f1 (SO2R) f2 (SO2R) f3 At least one of lithium difluorooxalate borate, lithium dioxalate borate, lithium perchlorate, and lithium hexafluoroarsenate, wherein R f1 R f2 R f3 R f4 R f5 and R f6 C n F 2n+1 And it satisfies 0 < n ≤ 10.

10. A battery, characterized in that, It includes a positive electrode, a solid electrolyte layer, and a negative electrode that are stacked sequentially; wherein the solid electrolyte layer is a solid electrolyte as described in any one of claims 1 to 9.

11. The battery according to claim 10, characterized in that, The thickness of the positive electrode active layer in the positive electrode sheet is 10 nm to 100 μm, or / and the thickness of the solid electrolyte layer is 10 nm to 100 μm, or / and the thickness of the negative electrode active layer in the negative electrode sheet is 10 nm to 100 μm.

12. An electrical appliance, characterized in that, Includes the battery as described in claim 10 or 11.

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