Solid-state battery, composite electrolyte membrane, method for manufacturing the same, and electric device

Abstract

This application relates to a solid-state battery, a composite electrolyte membrane, a method for preparing the same, and an electrical device thereof. The solid-state battery includes a positive electrode layer, a composite electrolyte layer, and a negative electrode layer stacked sequentially. The composite electrolyte layer comprises an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane. The organic polymer porous mesh membrane includes through-pores. The first electrolyte layer comprises a halide solid electrolyte, and the second electrolyte layer comprises a sulfide solid electrolyte. The first electrolyte layer is located between the positive electrode layer and the second electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the negative electrode layer. This solid-state battery exhibits a significantly extended cycle life.

Description

Technical Field

[0001] This application relates to the field of solid-state battery technology, and further to a solid-state battery, a composite electrolyte membrane, a method for preparing the same, and an electrical device thereof. Background Technology

[0002] The statements herein are provided only as background information in connection with this application and do not necessarily constitute prior art.

[0003] Solid-state batteries use a non-flammable solid electrolyte instead of the organic electrolyte in traditional liquid secondary batteries, significantly improving battery safety and are considered the next generation of batteries closest to industrialization. However, interface compatibility issues in solid-state batteries lead to less than ideal cycle performance. Summary of the Invention

[0004] According to various embodiments and examples of this application, this application provides a solid-state battery, a composite electrolyte membrane, a method for preparing the same, and an electrical device thereof, wherein the solid-state battery has a significantly extended cycle life.

[0005] In one aspect, this application provides a solid-state battery, which includes a positive electrode layer, a composite electrolyte layer and a negative electrode layer stacked sequentially.

[0006] In some embodiments, a solid-state battery is provided, comprising a positive electrode layer, a composite electrolyte layer, and a negative electrode layer stacked sequentially.

[0007] The composite electrolyte layer comprises an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer comprises a halide solid electrolyte, and the second electrolyte layer comprises a sulfide solid electrolyte.

[0008] The first electrolyte layer is located between the positive electrode layer and the second electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the negative electrode layer.

[0009] A composite electrolyte membrane with an asymmetric structure is incorporated in a solid-state battery. This membrane comprises a halide solid electrolyte on the positive electrode side, a sulfide solid electrolyte on the negative electrode side, and a porous organic polymer mesh membrane with through-pores. The halide solid electrolyte exhibits high-pressure oxidation resistance and good positive electrode interface compatibility, while the sulfide solid electrolyte demonstrates low-pressure resistance and good negative electrode interface compatibility. By placing the first solid electrolyte, including the halide solid electrolyte, on the positive electrode side and the second solid electrolyte, including the sulfide solid electrolyte, on the negative electrode side, the chemical stability of both the positive and negative electrode interfaces can be simultaneously ensured, achieving significant suppression of both positive and negative electrode interface degradation. Furthermore, the first and second solid electrolytes are connected using a porous organic polymer mesh membrane with through-pores. The first and second electrolyte layers are respectively disposed on opposite sides of the porous organic polymer mesh membrane, ensuring that at least the first electrolyte layer... A portion of the second electrolyte layer is embedded in a porous organic polymer mesh film, and at least a portion of the second electrolyte layer is also embedded in a porous organic polymer mesh film, achieving good ion conduction. This allows the composite electrolyte layer to maintain a certain high ionic conductivity while achieving good flexibility and mechanical strength, improving the structural stability of the composite electrolyte layer and its contact stability with the positive and negative electrode interfaces, and enhancing the stability of ion conduction between the positive and negative electrode layers. Through the aforementioned synergistic design, the composite electrolyte layer can provide solid-state batteries with good positive and negative electrode chemical interface stability, good ionic conductivity, good flexibility, and relatively stable positive and negative electrode interface contact, thereby significantly extending the cycle life of solid-state batteries.

[0010] The improvement described in any part of the context of this application is not intended to be limited by any theoretical constraints.

[0011] In addition, the composite electrolyte layer provides solid-state batteries with good chemical interface stability of positive and negative electrodes, good ionic conductivity, and relatively stable positive and negative electrode interface contact characteristics, which are conducive to promoting the capacity of positive and negative electrodes. This helps solid-state batteries to achieve high initial coulombic efficiency while significantly extending cycle life.

[0012] Furthermore, the good support, flexibility, and mechanical strength provided by the porous network membrane of the organic polymer make it possible to supply this composite electrolyte layer through an independent composite electrolyte membrane suitable for large-scale production.

[0013] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0014] (a1) The through holes include straight through holes; optionally, at least 80% of the through holes are straight through holes; further optionally, the through holes are straight through holes;

[0015] (a2) The composite electrolyte layer has an ionic conductivity greater than or equal to 1 mS / cm under at least one temperature condition between 25°C and 60°C; optionally, the composite electrolyte layer has an ionic conductivity greater than or equal to 1 mS / cm at 25°C.

[0016] (a3) The side of the through hole near the positive electrode layer is filled with the halide solid electrolyte, and the side of the through hole near the negative electrode layer is filled with the sulfide solid electrolyte;

[0017] (a4) The average diameter of the through holes is 1 μm to 200 μm, and optionally 5 μm to 100 μm, based on the dimension perpendicular to the thickness direction of the organic polymer porous mesh film;

[0018] (a5) In terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film, the diameter of the through hole at different thickness positions of the organic polymer porous mesh film ranges from 1 μm to 200 μm, and can be selected as 5 μm to 100 μm.

[0019] (b1) The organic polymer porous mesh membrane includes one or more of polyolefin fibers, polyamide fibers and polyester fibers;

[0020] (b2) The organic polymer porous mesh membrane includes polymer fibers, and optionally, the thermal decomposition temperature of the polymer fibers is greater than or equal to 200°C.

[0021] (b3) The mass percentage of the halide solid electrolyte in the first electrolyte layer is 80% to 100%;

[0022] (b4) The sulfide solid electrolyte accounts for 80% to 100% of the mass of the second electrolyte layer;

[0023] (c1) The tensile strength of the organic polymer porous mesh membrane or composite electrolyte layer is greater than or equal to 1 MPa;

[0024] (c2) The tortuosity of the organic polymer porous mesh membrane is 1 to 10;

[0025] (c3) The porosity of the organic polymer porous mesh membrane is 50% to 90%.

[0026] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0027] (a4') The average diameter of the through holes is 5 μm to 100 μm, measured in terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film;

[0028] (a5') In terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film, the diameter of the through hole at different thickness positions of the organic polymer porous mesh film ranges from 1 μm to 100 μm, and can be selected as 5 μm to 100 μm;

[0029] (b1') The organic polymer porous mesh membrane includes one or more of nylon fibers, polypropylene fibers and polyester fibers;

[0030] (b1”) The organic polymer porous mesh membrane includes a bio-based polymer fiber material. Optionally, the thermal decomposition temperature of the bio-based polymer fiber material is greater than or equal to 200°C, and can be 200°C to 800°C.

[0031] (b2') The organic polymer porous mesh membrane includes polymer fibers, and the thermal decomposition temperature of the polymer fibers is 200°C to 800°C;

[0032] (b3') The halide solid electrolyte accounts for 90% to 100% of the mass of the first electrolyte layer;

[0033] (b4') The sulfide solid electrolyte accounts for 90% to 100% of the mass of the second electrolyte layer;

[0034] (c1') The tensile strength of the organic polymer porous mesh membrane or composite electrolyte layer is greater than or equal to 10 MPa;

[0035] (c2') The tortuosity of the organic polymer porous mesh membrane is 1 to 3;

[0036] (c3') The porosity of the organic polymer porous mesh membrane is 50% to 80%.

[0037] By setting at least a portion of the through-holes as through-holes, better connectivity between the first and second electrolyte layers can be achieved, which is beneficial for the composite electrolyte layer to provide higher ionic conductivity, thus improving the cycle life of the solid-state battery. Furthermore, it is more conducive to maximizing the capacity of the negative electrode and improving the initial coulombic efficiency of the solid-state battery. Setting a higher number of through-holes (e.g., at least 80%) within the through-holes further enhances the ionic conductivity of the composite electrolyte layer.

[0038] By ensuring that the ionic conductivity of the composite electrolyte layer is greater than or equal to 1 mS / cm at at least one temperature condition (e.g., 25°C) between 25°C and 60°C, it is beneficial to improve the cycle life of solid-state batteries and the initial coulombic efficiency.

[0039] It is understood that the first electrolyte layer and the second electrolyte layer in the composite electrolyte layer are connected. Furthermore, the side of the through-hole closest to the positive electrode layer can be filled with a halide solid electrolyte, and the side of the through-hole closest to the negative electrode layer can be filled with a sulfide solid electrolyte. This helps to improve the uniformity of ionic conductivity distribution in the composite electrolyte layer, reduce polarization in the composite electrolyte film, and better improve the cycle life of the solid-state battery.

[0040] By controlling the average diameter of the through holes and the diameter range of the through holes at different thickness positions of the organic polymer porous mesh film within the aforementioned range, it is beneficial to maintain the good flexibility and mechanical strength of the organic polymer porous mesh film, and it is also more beneficial to embed the first electrolyte layer and the second electrolyte layer, and to improve the ionic conductivity of the composite electrolyte layer.

[0041] Organic polymer porous mesh membranes allow for flexible selection of more suitable polymer materials, achieving higher mechanical strength and better flexibility while further improving the performance of the organic polymer porous mesh membrane, thereby achieving better cycle life of solid-state batteries. For example, by controlling the thermal decomposition temperature of the polymer fibers in the organic polymer porous mesh membrane within the aforementioned range, it is beneficial to make the polymer fibers more suitable for the processing technology of organic polymer porous mesh membranes and solid-state batteries.

[0042] By controlling the mass percentage of the halide solid electrolyte in the first electrolyte layer (which can be denoted as F), M1 The mass percentage of sulfide solid electrolyte in the second electrolyte layer (which can be denoted as F) and the mass percentage of sulfide solid electrolyte in the second electrolyte layer. M2 Within the aforementioned range of one or two parameters, it is beneficial to obtain higher ionic conductivity for the composite electrolyte layer.

[0043] By controlling the tensile strength of the porous organic polymer membrane within the aforementioned range, it is possible to provide higher mechanical strength and improve processability during the preparation of the composite electrolyte membrane. Furthermore, the composite electrolyte layer in the solid-state battery can provide better flexibility, higher structural stability, and more stable positive and negative electrode interface contact, thus better balancing the improvement of the cycle life of the solid-state battery and the large-scale preparation of the composite electrolyte membrane.

[0044] By controlling one or both of the tortuosity and porosity of the organic polymer porous mesh membrane within the aforementioned range, it is beneficial to provide better ion transport channels. This not only provides a better connection between the first and second electrolyte layers but also allows the organic polymer porous mesh membrane to provide better support and flexibility, thus balancing good ionic conductivity, good flexibility, and high structural stability of the composite electrolyte layer. Furthermore, it can better balance good ionic conductivity and high mechanical strength of the composite electrolyte membrane. The lower the tortuosity of the organic polymer porous mesh membrane, the more beneficial it is to improving the ion conductivity of the composite electrolyte layer.

[0045] It is understandable that the composite electrolyte layer can have better overall performance by adjusting one or more parameters of the organic polymer porous mesh membrane, such as tensile strength, tortuosity, and porosity, in order to better improve the cycle life of solid-state batteries.

[0046] It is understandable that by adjusting one or more parameters of the tensile strength, tortuosity, and porosity of the organic polymer porous mesh membrane, the composite electrolyte layer can have better overall performance, so as to better balance the improvement of the cycle life of solid-state batteries and the large-scale preparation of composite electrolyte membranes.

[0047] It is understood that the overall performance of the composite electrolyte layer can be optimized by adjusting one or more of the aforementioned features (a1) to (a5), (b1) to (b4), (c1) to (c3) and optional features within the aforementioned feature range, so as to better improve the cycle life of solid-state batteries, or better balance the improvement of the cycle life of solid-state batteries and the large-scale preparation of composite electrolyte membranes.

[0048] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0049] (d1) The thickness of the first electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer;

[0050] (d2) The thickness of the second electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer;

[0051] (d3) The thickness of the organic polymer porous mesh membrane is 60% to 100% of the thickness of the composite electrolyte layer;

[0052] (d4) The thickness of the organic polymer porous mesh membrane is greater than or equal to 10 μm;

[0053] (d5) The organic polymer porous mesh membrane accounts for 5% to 30% of the mass of the composite electrolyte layer;

[0054] (d6) The halide solid electrolyte accounts for 5% to 90% of the mass of the composite electrolyte layer;

[0055] (d7) The sulfide solid electrolyte accounts for 5% to 90% of the mass of the composite electrolyte layer;

[0056] (d8) The composite electrolyte layer includes a fibrous polymer binder, wherein the fibrous polymer binder accounts for 0.1% to 5% of the mass of the composite electrolyte layer.

[0057] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0058] (d1') The thickness of the first electrolyte layer is 45% to 55% of the thickness of the composite electrolyte layer;

[0059] (d2') The thickness of the second electrolyte layer is 45% to 55% of the thickness of the composite electrolyte layer;

[0060] (d3') The thickness of the organic polymer porous mesh membrane is 80% to 100% of the thickness of the composite electrolyte layer;

[0061] (d4') The thickness of the organic polymer porous mesh membrane is 10 μm to 150 μm;

[0062] (d5') ​​The organic polymer porous mesh membrane accounts for 5% to 20% of the mass of the composite electrolyte layer;

[0063] (d6') The halide solid electrolyte accounts for 40% to 60% of the mass of the composite electrolyte layer;

[0064] (d7') The sulfide solid electrolyte accounts for 40% to 60% of the mass of the composite electrolyte layer;

[0065] (d8') The composite electrolyte layer includes a fibrous polymer binder, wherein the fibrous polymer binder accounts for 1% to 5% of the mass of the composite electrolyte layer;

[0066] (d8”) At least one of the first electrolyte layer and the second electrolyte layer includes a fibrous polymer binder.

[0067] By using the percentage of the thickness of the first electrolyte layer relative to the thickness of the composite electrolyte layer (F) H1 The percentage of the thickness of the second electrolyte layer relative to the thickness of the composite electrolyte layer (F) H2The percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F) H0 ), the thickness (D0) of the organic polymer porous mesh membrane, and the mass percentage (F) of the organic polymer porous mesh membrane in the composite electrolyte layer. M0 ), the mass percentage of halide solid electrolytes in the composite electrolyte layer (F) M1 ), the mass percentage of sulfide solid electrolyte in the composite electrolyte layer (F) M2 Controlling one or more parameters of the mass ratio of the optional fibrous polymer binder in the composite electrolyte layer within the aforementioned range is beneficial for better balancing the synergistic effects of the first electrolyte layer, the second electrolyte layer, and the organic polymer porous mesh membrane, and for better leveraging the multiple functions of the composite electrolyte layer. This allows the composite electrolyte layer to better provide good positive and negative electrode chemical interface stability, good ionic conductivity, good flexibility, high structural stability, and more stable positive and negative electrode interface contact, thereby significantly extending the cycle life of the solid-state battery.

[0068] For example, by controlling one or more of the following parameters within the aforementioned ranges—the mass percentage of halide solid electrolyte in the composite electrolyte layer, the mass percentage of sulfide solid electrolyte in the composite electrolyte layer, and the mass percentage of optional fibrous polymer binder in the composite electrolyte layer—the content of solid electrolyte with high ionic conductivity in the composite electrolyte layer can be controlled within a more suitable range, thereby providing the composite electrolyte layer with higher ionic conductivity while also achieving better flexibility, higher structural stability, and more stable positive and negative electrode interface contact.

[0069] In some embodiments, the thickness of the organic polymer porous mesh membrane is 30 μm to 150 μm, and the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer is 80% to 100%, optionally greater than or equal to 80% and less than 100%, and further optionally 80% to 95%.

[0070] By using the thickness of the organic polymer porous mesh membrane and the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F... H At the same time, keeping it within the aforementioned range helps reduce the risk of internal short circuits and improve the reliability of solid-state batteries.

[0071] In some embodiments, the thickness of the organic polymer porous mesh membrane is 10 μm to 30 μm. This allows the thickness of the composite electrolyte membrane to be controlled within a relatively thin range, which is beneficial for reducing the weight of the solid-state battery, increasing its energy density, reducing internal resistance, improving rate performance, and lowering costs.

[0072] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0073] (t1) The thickness of the organic polymer porous mesh membrane is greater than or equal to 80% and less than 100% of the thickness of the composite electrolyte layer, and can be selected as 80% to 95%;

[0074] (t2) At least one of the first electrolyte layer and the second electrolyte layer includes a portion located outside the organic polymer porous mesh membrane; optionally, both the first electrolyte layer and the second electrolyte layer include a portion located outside the organic polymer porous mesh membrane.

[0075] By controlling the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer within the aforementioned range, it is beneficial to improve battery cycle life while also taking into account flexibility and battery internal resistance.

[0076] At least one of the second electrolyte layers includes a portion located outside the porous organic polymer mesh membrane, which is more conducive to improving electrical contact with adjacent electrode layers.

[0077] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0078] (e1) The maximum particle size, D of the halide solid electrolyte in the first electrolyte layer v 99 or with an average particle size of 1μm to 50μm;

[0079] (e2) The maximum particle size of the sulfide solid electrolyte in the second electrolyte layer, D v 99 or with an average particle size of 1μm to 50μm.

[0080] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0081] (e1') The maximum particle size of the halide solid electrolyte in the first electrolyte layer, D v 99 or with an average particle size of 1μm to 10μm;

[0082] (e2') The maximum particle size of the sulfide solid electrolyte in the second electrolyte layer, D v 99 or with an average particle size of 1μm to 10μm.

[0083] By adjusting the maximum particle size of the halide solid electrolyte in the first electrolyte layer, D v 99 or average particle size and the maximum particle size of the sulfide solid electrolyte in the second electrolyte layer, D vControlling one or two parameters, such as the average particle size, within the aforementioned range is beneficial for better filling in the composite electrolyte layer and for improving the ionic conductivity of the composite electrolyte layer.

[0084] In some embodiments, the composite electrolyte layer has an ionic conductivity of 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C.

[0085] Optionally, the ionic conductivity of the composite electrolyte layer at 25°C is 1 mS / cm to 10 mS / cm.

[0086] In some embodiments, the composite electrolyte layer has an ionic conductivity of 1 mS / cm to 5 mS / cm at at least one temperature condition between 25°C and 60°C.

[0087] Optionally, the ionic conductivity of the composite electrolyte layer at 25°C is 1 mS / cm to 5 mS / cm.

[0088] By controlling the ionic conductivity of the composite electrolyte layer within the aforementioned range, it is beneficial to improve the cycle performance of solid-state batteries.

[0089] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics:

[0090] (f1) The ionic conductivity of the halide solid electrolyte is 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C; optionally, the ionic conductivity of the halide solid electrolyte at 25°C is 1 mS / cm to 10 mS / cm.

[0091] (f2) The halide solid electrolyte includes any one or more of LiInCl, Li3YBr6 or Li3YCl6;

[0092] (f3) The sulfide solid electrolyte includes one or more of the following: silver sulfide-germanium sulfide type sulfide electrolyte, LGPS type sulfide electrolyte, and lithium sulfide-phosphorus pentasulfide complex type sulfide electrolyte;

[0093] (f4) The ionic conductivity of the sulfide solid electrolyte is 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C; optionally, the ionic conductivity of the sulfide solid electrolyte at 25°C is 1 mS / cm to 10 mS / cm.

[0094] (f5) The first electrolyte layer includes a first fibrous polymer binder; the first fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin has a mass percentage of 0.1% to 5% in the first electrolyte layer, optionally 1% to 2%; optionally, the first fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer and polyvinylidene fluoride;

[0095] (f6) The second electrolyte layer includes a second fibrous polymer binder; the second fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin has a mass percentage of 0.1% to 5% in the second electrolyte layer, optionally 1% to 2%; optionally, the second fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer and polyvinylidene fluoride.

[0096] The composite electrolyte layer allows for flexible selection of more suitable halide solid electrolytes, sulfide solid electrolytes, binders in the first electrolyte layer, and binders in the second electrolyte layer, in order to better improve the cycle performance of solid-state batteries.

[0097] In some embodiments, the positive electrode layer includes a positive electrode active layer, the positive electrode active layer includes a positive electrode active material, and the positive electrode active material includes a lithium transition metal oxide positive electrode material.

[0098] In some embodiments, the positive electrode active material includes a lithium nickel-based oxide positive electrode material; wherein the lithium nickel-based oxide positive electrode material contains Li, a non-lithium metal element, and O, and the non-lithium metal element includes Ni.

[0099] The lithium nickel-based oxide cathode material satisfies one or more of the following characteristics:

[0100] (i) The atomic molar ratio of Ni to non-lithium metal elements in the lithium nickel-based oxide cathode material is q1, where 0.5 ≤ q1 ≤ 0.98;

[0101] (ii) The lithium nickel-based oxide cathode material contains Ni and Li elements in an atomic molar ratio of q2:x2, wherein 0.5≤q2≤0.98 and 0.6≤x2≤1.2;

[0102] (iii) The lithium nickel-based oxide cathode material comprises Ni and O elements in an atomic molar ratio of q3:x3, wherein 0.5≤q3≤0.98 and 1.6≤x3≤2.2; optionally, 1.6≤x3≤2.1;

[0103] (iv) The lithium nickel-based oxide cathode material contains Co.

[0104] (v) The lithium nickel-based oxide cathode material contains at least one of Mn and Al elements; optionally, the lithium nickel-based oxide cathode material contains Mn elements.

[0105] In some embodiments, the positive electrode active material satisfies one or more of the following characteristics:

[0106] (ti)0.8≤q1≤0.98;

[0107] (tii)0.8≤q2≤0.98;

[0108] (tiii) 0.8 ≤ x² ≤ 1.1;

[0109] (tiv)0.8≤q3≤0.98;

[0110] (tv)1.8≤x3≤2.06;

[0111] (tvi) The positive electrode active material includes lithium nickel cobalt manganese-based oxide positive electrode material. Optionally, the mass percentage of the lithium nickel cobalt manganese-based oxide positive electrode material in the positive electrode active material is 80% to 100%, and optionally 90% to 100%.

[0112] (tvii) The lithium nickel-based oxide cathode material accounts for 80% to 100% of the mass of the cathode active material, and can be selected as 90% to 100%.

[0113] The appropriate type of positive electrode active material can be placed in the positive electrode layer according to the performance requirements of solid-state batteries. For example, the energy density of solid-state batteries can be improved by setting lithium nickel-based oxide positive electrode materials (lithium nickel cobalt manganese-based oxide positive electrode materials).

[0114] In some embodiments, the solid-state battery is an all-solid-state battery.

[0115] In some embodiments, the solid-state battery is a lithium-ion secondary battery, which may be an all-solid-state lithium-ion secondary battery.

[0116] In a second aspect of this application, a composite electrolyte membrane is provided, which includes a composite electrolyte layer, the definition of which can be found in the first aspect of this application.

[0117] In some embodiments, a composite electrolyte membrane is provided, comprising a composite electrolyte layer, the composite electrolyte layer comprising an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer comprises a halide solid electrolyte, and the second electrolyte layer comprises a sulfide solid electrolyte.

[0118] In some embodiments, the features of the composite electrolyte layer are the same as those in the first aspect of this application.

[0119] In this composite electrolyte membrane, the use of an organic polymer porous network membrane improves the flexibility and mechanical strength while maintaining good ionic conductivity. The composite electrolyte membrane can provide a composite electrolyte layer with good ionic conductivity, good flexibility, high mechanical strength and stable positive and negative electrode interface contact for solid-state batteries, which is conducive to independent large-scale production.

[0120] In a third aspect of this application, a method for preparing a composite electrolyte membrane is provided, which can be used to prepare a solid-state battery according to the first aspect of this application.

[0121] In some embodiments, a method for preparing a composite electrolyte membrane is provided, comprising the following steps: placing a first electrolyte membrane and a second electrolyte membrane on opposite sides of an organic polymer porous mesh membrane, and hot rolling them together to embed at least a portion of the second electrolyte membrane into the organic polymer porous mesh membrane, thereby preparing a composite electrolyte membrane; wherein the organic polymer porous mesh membrane includes through-pores, the first electrolyte membrane includes a halide solid electrolyte, and the second electrolyte membrane includes a sulfide solid electrolyte.

[0122] In some embodiments, the method for preparing the composite electrolyte membrane satisfies one or more of the following characteristics:

[0123] (g1) The first electrolyte membrane is prepared by a method comprising the following steps: mixing a first solid electrolyte and a first fibrous polymer binder, and hot rolling to obtain the first electrolyte membrane; wherein, the first solid electrolyte comprises a halide solid electrolyte;

[0124] (g2) The second electrolyte membrane is prepared by a method including the following steps: mixing a second solid electrolyte and a second fibrous polymer binder, and hot rolling to obtain the second electrolyte membrane; wherein the second solid electrolyte includes a sulfide solid electrolyte.

[0125] In some embodiments, the prepared composite electrolyte membrane is the composite electrolyte membrane described in the second aspect of this application.

[0126] Composite electrolyte membranes can be prepared using simple methods suitable for large-scale production.

[0127] In a fourth aspect of this application, an electrical device includes at least one of the solid-state battery described in the first aspect of this application, the composite electrolyte membrane described in the second aspect of this application, and the composite electrolyte membrane prepared by the method described in the third aspect of this application.

[0128] Electrical devices including the aforementioned solid-state batteries and / or the aforementioned composite electrolyte membranes may have corresponding advantages, which will not be elaborated here.

[0129] Details of one or more embodiments or examples of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0130] To better describe and illustrate the embodiments, examples, or models provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments, examples, or models, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0131] Figure 1 This is a schematic diagram of a solid-state battery cell according to one embodiment of this application.

[0132] Figure 2 for Figure 1 An exploded view of a solid-state battery cell according to an embodiment of this application is shown.

[0133] Figure 3 This is a schematic diagram of a battery device according to one embodiment of this application.

[0134] Figure 4 This is a schematic diagram of a battery pack according to one embodiment of this application.

[0135] Figure 5 for Figure 4 An exploded view of a battery pack according to one embodiment of this application is shown.

[0136] Figure 6 This is a schematic diagram of an electrical device that uses a solid-state battery as a power source according to one embodiment of this application.

[0137] Figure 7This is a tensile curve of the composite electrolyte membrane in one embodiment of this application. The vertical axis represents the tensile force in Newtons (N), and the horizontal axis represents the elongation (denoted as "displacement") in millimeters (mm).

[0138] Figure 8 The above is the electrochemical impedance spectroscopy (EIS) test result of the composite electrolyte membrane in one embodiment of this application. The horizontal axis is Z' (in Ω) and the vertical axis is -Z" (in Ω). Z' and Z" correspond to the real part (resistance) and imaginary part (reactance) of the complex impedance, respectively.

[0139] Figure 9 This is the test result of the first charge-discharge cycle of a solid-state battery in one embodiment of this application.

[0140] Explanation of reference numerals in the attached figures:

[0141] 1. Battery pack; 2. Upper casing; 3. Lower casing; 4. Battery assembly; 5. Solid-state battery cell; 51. Housing; 52. Solid-state battery cell; 53. Cover plate; 6. Electrical device. Detailed Implementation

[0142] The following describes in detail, with appropriate reference to the accompanying drawings, some embodiments of the solid-state battery, composite electrolyte membrane, preparation method thereof, and electrical device of this application. However, some unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0143] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints. Any endpoint can be included or excluded independently and can be combined arbitrarily; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0" and "5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when describing a parameter as an integer ≥ 2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 for that parameter. For instance, when describing a parameter as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0144] In this application, the term "numerical value" includes the number itself and its reasonable approximations. The definition of "numerical value" can apply to discrete numerical points or to the endpoints of a numerical range. Unless otherwise specified, the term "approximation" covers a numerical interval based on a reasonable range of fluctuations of the number itself. This reasonable range of fluctuations can vary depending on the type and magnitude of the number. This reasonable range of fluctuations can be reasonably determined based on the accuracy of the testing or measurement method. Therefore, when referring to a numerical value or a numerical range, unless otherwise specified, it should be understood that the numerical value includes its reasonable approximation, and the numerical range includes reasonable approximations at both endpoints. Those skilled in the art will understand that acceptable fluctuation ranges of the relevant approximations can be included within the definition of the numerical value or the numerical range. In this application, unless otherwise specified, "N1" can be reasonably understood as "about N1," and "N1~N2" can be reasonably understood as "about N1 to about N2," where N1 and N2 are two unequal numerical values.

[0145] In this application, unless otherwise specified, "about" means within a reasonable range above and below the stated number, and the range of fluctuation may vary depending on the type and value of the stated number. For example, a range of ±10%, ±5%, ±2%, ±1%, etc., may be allowed. For example, taking "about 20°C" and its approximation as ±1°C, approximate values ​​such as 19°C, 19.5°C, etc., within the approximation range indicated by "about 20°C" should also be included in the range indicated by "about 20°C".

[0146] In this application, the terms "multiple," "various," "multiple items," "several," etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more (greater than or equal to) two. It can be understood that when "any number of" items are involved, it refers to any suitable combination of multiple items, that is, a combination of "any number of" items in a manner that does not conflict and enables the implementation of this application.

[0147] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0148] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0149] Those skilled in the art will understand that, unless otherwise specified, the order in which the steps are written in the various embodiments or methods of this application does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, but are preferably performed sequentially. For example, if method M includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, method M may also include step (c), meaning that step (c) can be added to method M in any order. For example, method M may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0150] In this application, open-ended technical features or solutions described using terms such as "containing," "comprising," or "including" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, if 'a' includes a1, a2, and a3, it may also include other members or exclude additional members unless otherwise specified. This can be considered as providing both features or solutions where "a consists of a1, a2, and a3" or "a is selected from a1, a2, and a3," and features or solutions where "a includes not only a1, a2, and a3, but also other members."

[0151] In this application, unless otherwise specified, M (e.g., m1) means that m1 is a non-limiting example of M, and it is understood that M is not limited to m1.

[0152] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. Unless otherwise specified, the descriptions such as "optionally include" and "optionally contain" in this application, taking "optionally include" as an example, mean "may include or not include."

[0153] In this application, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. Any and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "M and / or N" represents the group consisting of M, N, and "a combination of M and N". "Containing M and / or N" can mean "containing M, containing N, and containing both M and N", or "containing M, containing N, or containing both M and N", and can be appropriately understood according to the context.

[0154] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0155] In this document, the term "suitable" in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the technical solution that enables the implementation of this application.

[0156] In this document, terms such as "preferred," "better," "more suitable," "ideal," "good," and "superior" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0157] In this application, terms such as "further," "even more," "especially," "for example," "as," "example," and "exemplary" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0158] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0159] In this application, unless otherwise expressly specified and limited, the phrase "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In this application, unless otherwise expressly specified and limited, the phrase "above" or "below" the second feature can indicate a horizontal positional relationship, or it can simply indicate the existence of an attachment relationship without specifying a horizontal positional relationship.

[0160] In this application, the term "room temperature" generally refers to 4℃ to 35℃, and may refer to 20℃ ± 5℃. In some embodiments or examples of this application, room temperature refers to 20℃ to 30℃.

[0161] In this application, if the unit for a data range is only followed by the right endpoint, it indicates that the units for the left and right endpoints are the same. For example, 3~5h or 3-5h both mean that the unit for the left endpoint "3" and the right endpoint "5" is h (hours), and both have the same meaning as 3h~5h. Furthermore, similar descriptions of other parameters such as temperature and size are interpreted in the same way.

[0162] In this application, the exemplary descriptions such as "in some implementations (or embodiments)" and "in one implementation (or embodiment)" may cover, but are not limited to, the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0163] Unless otherwise stated, the improvements described in this application are not intended to be limited to any theoretical constraints.

[0164] For any test method for a certain parameter described in this application, as long as the test result of at least one test method is within the described range, it can be included in the protection scope of this application.

[0165] Typically, the positive electrode has a high potential, while the negative electrode has a low potential. Therefore, the positive and negative electrodes have different requirements for the redox properties of the solid electrolyte. A solid electrolyte with high-voltage oxidation resistance can be introduced on the positive electrode side, while a solid electrolyte with low-voltage resistance can be introduced on the negative electrode side. This structural design presents a challenge in how the solid electrolyte layer can simultaneously maintain the chemical stability of both the positive and negative electrode interfaces. In traditional solid-state battery designs, sulfide electrolytes are commonly used as solid electrolyte layers due to their extremely high ionic conductivity. However, the chemical stability of this traditional solid electrolyte layer at the high-voltage positive electrode interface is poor, and it is prone to degradation. Using a halide electrolyte, which has better chemical stability at the high-voltage positive electrode interface, leads to unsatisfactory chemical stability at the negative electrode interface. A solid electrolyte layer with a single solid electrolyte component cannot simultaneously achieve chemical stability at both the positive and negative electrode interfaces.

[0166] Furthermore, in existing methods for fabricating solid-state batteries based on independent solid electrolyte membranes, a high content of inorganic solid electrolyte (such as a high content of sulfide electrolyte) is typically incorporated into the solid electrolyte membrane to improve its ionic conductivity. However, these types of solid electrolyte membranes generally have poor flexibility, making them difficult to apply to large-scale production.

[0167] According to various embodiments and examples of this application, this application provides a solid-state battery, a composite electrolyte membrane, a method for preparing the same, and an electrical device thereof, wherein the solid-state battery has a significantly extended cycle life.

[0168] In some embodiments, a solid-state battery is provided, comprising a positive electrode layer, a solid electrolyte layer and a negative electrode layer stacked sequentially, wherein the solid electrolyte layer includes a composite electrolyte layer.

[0169] In some embodiments, the solid-state battery includes a positive electrode layer, a composite electrolyte layer, and a negative electrode layer stacked sequentially; wherein, the composite electrolyte layer includes an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer includes a solid electrolyte with high-pressure oxidation resistance (which may be referred to as the first solid electrolyte), and the second electrolyte layer includes a solid electrolyte with low-pressure resistance (which may be referred to as the second solid electrolyte); the first electrolyte layer is located between the positive electrode layer and the second electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the negative electrode layer.

[0170] In this application, "layered arrangement" refers to the description of the stacking direction between layered structures. For example, "including structural layer A and structural layer B in a layered arrangement" means that the stacking direction of structural layer A and structural layer B is along their respective layer thickness directions, that is, the thickness direction of structural layer A and the thickness direction of structural layer B are the same or substantially the same.

[0171] In this application, the "solid electrolyte with high-pressure oxidation resistance" on the positive electrode side can be referred to as the first solid electrolyte, and the "solid electrolyte with low-pressure resistance" on the negative electrode layer can be referred to as the second solid electrolyte.

[0172] Non-limiting examples of first solid electrolytes include halide solid electrolytes.

[0173] Non-limiting examples of second solid electrolytes include sulfide solid electrolytes.

[0174] In some embodiments, the first solid electrolyte includes a halide solid electrolyte, and optionally other types of solid electrolytes that have high-pressure oxidation resistance equal to or better than that of halide solid electrolytes and also have good ionic conductivity. For the ionic conductivity of other types of solid electrolytes in the first solid electrolyte, refer to the ionic conductivity of halide solid electrolytes described in the context of this application.

[0175] In some embodiments, the second solid electrolyte includes a sulfide solid electrolyte, and optionally other types of solid electrolytes with low-pressure resistance equal to or better than that of the sulfide solid electrolyte while also having good ionic conductivity. For the ionic conductivity of other types of solid electrolytes in the context of this application, refer to the ionic conductivity of sulfide solid electrolytes.

[0176] The redox stability of solid electrolytes can be evaluated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Furthermore, the stability of composite electrolyte layers can also be evaluated by measuring impedance changes before and after battery cycling.

[0177] In this application, the solid electrolyte layer between the positive electrode layer and the negative electrode layer includes a composite electrolyte layer.

[0178] Some embodiments of the solid-state battery in this application introduce a composite electrolyte layer with an asymmetric design on both sides. This composite electrolyte layer contains different types of solid electrolytes on the positive and negative electrode sides. A solid electrolyte with high-voltage oxidation resistance (such as a halide solid electrolyte) is placed on the positive electrode side, while a solid electrolyte with low-voltage resistance (such as a sulfide solid electrolyte) is placed on the negative electrode side. This allows the composite electrolyte layer to be compatible with both the positive and chemical interfaces, exhibiting good chemical stability with both high-voltage positive and negative electrode interfaces. Furthermore, based on a flexible, porous organic polymer mesh film with through-holes, a first solid electrolyte and a second solid electrolyte are embedded on both sides of the organic polymer porous mesh film, ensuring good connection between the two through-holes and achieving good ion conduction. This composite electrolyte layer not only simultaneously maintains chemical stability at both the positive and negative electrode interfaces but also possesses good ionic conductivity, good flexibility, high mechanical strength, good structural stability, and stable positive and negative electrode interface contact. Furthermore, the good support, flexibility, and mechanical strength provided by the porous network membrane of the organic polymer make it possible to supply this composite electrolyte layer through an independent composite electrolyte membrane suitable for large-scale production.

[0179] Unless otherwise specified, the term "solid-state battery" in this application refers to a battery in which the electrolyte includes a solid electrolyte. Typically, a solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. During charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode layers. The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers and also isolates them, preventing short circuits. Therefore, a separator, as found in traditional lithium-ion batteries, is not required in solid-state batteries. Solid-state batteries use a non-flammable solid electrolyte instead of the organic electrolyte in traditional liquid lithium-ion batteries, significantly improving battery safety. In addition to enhanced safety, solid-state batteries are better suited for high-energy-density positive and negative electrode materials and reduce system weight, thus facilitating improvements in energy density.

[0180] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in solid form during the storage and fabrication of solid-state batteries and their components, as well as during the operation of solid-state batteries. This includes, but is not limited to, solid electrolytes existing in solid form at room temperature.

[0181] In this application, unless otherwise specified, "electrode layer" includes electrode active material. The electrode layer can be a positive electrode layer or a negative electrode layer. "Electrode active material" in the electrode layer refers to a material capable of reversibly inserting and extracting active ions. Unless otherwise specified, "negative electrode active material" refers to a material used in the negative electrode layer capable of reversibly inserting and extracting active ions; "positive electrode active material" refers to a material used in the positive electrode layer capable of reversibly extracting and inserting active ions. During solid-state battery charging, active ions are extracted from the positive electrode, pass through the solid electrolyte layer, and insert into the negative electrode; during solid-state battery discharging, active ions are extracted from the negative electrode and insert into the positive electrode. The active ions are not particularly limited; non-limitingly, the active ions can be lithium ions, corresponding to a lithium-ion solid-state battery.

[0182] In this application, unless otherwise specified, "electrode active layer" includes at least one of the positive active layer in the positive electrode layer and the negative active layer in the negative electrode layer. Depending on the specific circumstances, the electrode active layer may refer to either the positive active layer or the negative active layer. It is understood that the positive active layer includes the positive active material and may also be referred to as the "positive active material layer"; the negative active layer includes the negative active material and may also be referred to as the "negative active material layer".

[0183] In a first aspect of this application, a solid-state battery is provided, comprising a positive electrode layer, a composite electrolyte layer, and a negative electrode layer stacked sequentially.

[0184] In some embodiments, a solid-state battery is provided, comprising a positive electrode layer, a composite electrolyte layer, and a negative electrode layer stacked sequentially; wherein the composite electrolyte layer comprises an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer comprises a halide solid electrolyte, and the second electrolyte layer comprises a sulfide solid electrolyte; the first electrolyte layer is located between the positive electrode layer and the second electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the negative electrode layer.

[0185] In this application, unless otherwise specified, an "organic polymer porous mesh membrane" is a porous mesh membrane comprising an organic polymer material. The organic polymer porous mesh membrane has a first surface and a second surface facing away from each other, wherein the distance between the first surface and the second surface corresponds to the thickness of the organic polymer porous mesh membrane. The organic polymer porous mesh membrane has pores, at least a portion of which form through-holes, such that at least a portion of the first electrolyte layer is embedded in the organic polymer porous mesh membrane, and at least a portion of the second electrolyte layer is embedded in the organic polymer porous mesh membrane. Thus, a first solid electrolyte (such as a halide solid electrolyte) in the first electrolyte layer and a second solid electrolyte (such as a sulfide solid electrolyte) in the second electrolyte layer are filled within the organic polymer porous mesh membrane, enabling the composite electrolyte layer to achieve good ion conduction.

[0186] In this application, unless otherwise specified, a "through-hole" in an organic polymer porous mesh membrane refers to a connection or permeability between the two surfaces of the organic polymer porous mesh membrane along its thickness direction. The connecting path of the through-hole from the first surface to the second surface can be a straight line or can have a certain degree of tortuosity.

[0187] The "through pores" in the porous network membrane of organic polymer are formed by one or more of the following methods: mechanical drilling, laser drilling, chemical etching, mechanical stretching, and heavy ion drilling.

[0188] The through-pores in the porous network membrane of organic polymers not only give the porous network membrane a micron-scale network structure on a macroscopic scale, which is different from the molecular-level network structure in cross-linked polymers, but also from polymer networks obtained by traditional weaving methods.

[0189] In this application, the "composite electrolyte layer" uses an organic polymer porous mesh membrane as a flexible substrate. A first electrolyte layer and a second electrolyte layer are embedded on both sides of the organic polymer porous mesh membrane, respectively. The organic polymer porous mesh membrane includes through holes, which provide channels for the embedding and connection of the first electrolyte layer and the second electrolyte layer. As a result, the composite electrolyte layer has good mechanical strength and flexibility in addition to good ionic conductivity, and good structural stability.

[0190] It is understood that the first and second electrolyte layers in the composite electrolyte layer are connected. Therefore, the composite electrolyte layer achieves high ionic conductivity (e.g., ≥1 mS / cm) based on the synergistic effect of the halide solid electrolyte in the first electrolyte layer and the sulfide solid electrolyte in the second electrolyte layer. In the composite electrolyte membrane, the first and second electrolyte layers can be connected through the through-pores in the porous network membrane of the organic polymer. By controlling the degree of connection between the first and second electrolyte layers in the composite electrolyte membrane, the ionic conductivity of the composite electrolyte membrane can be adjusted. For example, by controlling the degree of connection between the first and second electrolyte layers in the composite electrolyte membrane, the ionic conductivity of the composite electrolyte membrane can meet the desired level, such as ≥1 mS / cm.

[0191] A composite electrolyte membrane with an asymmetric structure is incorporated in a solid-state battery. This membrane comprises a halide solid electrolyte on the positive electrode side, a sulfide solid electrolyte on the negative electrode side, and a porous organic polymer mesh membrane with through-pores. The halide solid electrolyte exhibits high-pressure oxidation resistance and good positive electrode interface compatibility, while the sulfide solid electrolyte demonstrates low-pressure resistance and good negative electrode interface compatibility. By placing the first solid electrolyte, including the halide solid electrolyte, on the positive electrode side and the second solid electrolyte, including the sulfide solid electrolyte, on the negative electrode side, the chemical stability of both the positive and negative electrode interfaces can be simultaneously ensured, achieving significant suppression of both positive and negative electrode interface degradation. Furthermore, the first and second solid electrolytes are connected using a porous organic polymer mesh membrane with through-pores. The first and second electrolyte layers are respectively disposed on opposite sides of the porous organic polymer mesh membrane, ensuring that at least the first electrolyte layer... A portion of the second electrolyte layer is embedded in a porous organic polymer mesh film, and at least a portion of the second electrolyte layer is also embedded in a porous organic polymer mesh film, achieving good ion conduction. This allows the composite electrolyte layer to maintain a certain high ionic conductivity while achieving good flexibility and mechanical strength, improving the structural stability of the composite electrolyte layer and its contact stability with the positive and negative electrode interfaces, and enhancing the stability of ion conduction between the positive and negative electrode layers. Through the aforementioned synergistic design, the composite electrolyte layer can provide solid-state batteries with good positive and negative electrode chemical interface stability, good ionic conductivity, good flexibility, and relatively stable positive and negative electrode interface contact, thereby significantly extending the cycle life of solid-state batteries.

[0192] In addition, the composite electrolyte layer provides solid-state batteries with good chemical interface stability of positive and negative electrodes, good ionic conductivity, and relatively stable positive and negative electrode interface contact characteristics, which are conducive to promoting the capacity of positive and negative electrodes. This helps solid-state batteries to achieve high initial coulombic efficiency while significantly extending cycle life.

[0193] Furthermore, the good support, flexibility, and mechanical strength provided by the porous network membrane of the organic polymer make it possible to supply this composite electrolyte layer through an independent composite electrolyte membrane suitable for large-scale production.

[0194] In this application, the structure of the "composite electrolyte layer" and its "through-holes" can be tested and analyzed using methods such as scanning electron microscopy (SEM) and computed tomography (CT). The X-ray source for CT can be X-ray beam, gamma ray, ultrasound, etc. Liquid nitrogen can be used to quench the composite electrolyte membrane or solid battery cell along its thickness, allowing for microscopic morphological observation of the cross-section. Non-limitingly, instruments including, but not limited to, focused electron beam (FIB) microscopes (non-limiting examples such as the FEI Scios 2HiVac device) and ion cross-section polishers (non-limiting examples such as the JEOL IB-09010CP argon ion cross-section polisher and IB-19500CP ion cross-section polisher) can be used to process the solid battery cell to obtain the cross-section to be observed. Microscopic morphology observation methods can employ instruments or equipment including, but not limited to, scanning electron microscopy (SEM). High-resolution field emission scanning electron microscopes are not limited to this; non-limiting examples of SEM instruments include the Sigma 300 scanning electron microscope and the Apreo 2SEM field emission scanning electron microscope from ZEISS GmbH, Germany. Microscopic morphology analysis can also be performed on surfaces perpendicular to the thickness of composite electrolyte membranes or layers to observe through-holes and analyze their dimensions.

[0195] Scanning electron microscopy (SEM) and computed tomography (CT) can be combined with elemental analysis to analyze the first electrolyte layer, the second electrolyte layer, and the porous organic polymer network membrane in the composite electrolyte layer. Non-limitingly, focused electron beam (FIB) serial sectioning, cross-sectional SEM morphology observation, energy dispersive spectroscopy (EDS or EDX) elemental energy dispersive spectroscopy, and three-dimensional reconstruction analysis software can be used to analyze the first electrolyte layer, the second electrolyte layer, and the porous organic polymer network membrane in the composite electrolyte layer. For example, the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM can be used to reconstruct the three-dimensional structure of the sample, and EDS elemental energy dispersive spectroscopy analysis can be used to obtain the distribution of each element. Therefore, it is possible to test and analyze parameters such as the embedding status, position, particle composition and distribution, component composition and distribution, and size of the first and second electrolyte layers in the organic polymer porous mesh membrane. These parameters can be used to analyze parameters such as the average diameter of the through holes, the diameter range of the through holes at different thickness positions in the organic polymer porous mesh membrane, the percentage of the thickness of the first electrolyte layer relative to the thickness of the composite electrolyte layer, the percentage of the thickness of the second electrolyte layer relative to the thickness of the composite electrolyte layer, the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer, the thickness of the organic polymer porous mesh membrane, the maximum and average particle size of the halide solid electrolyte in the first electrolyte layer, the maximum and average particle size of the sulfide solid electrolyte in the second electrolyte layer, and the tortuosity of the organic polymer porous mesh membrane. For example, the three-dimensional structure of the sample is reconstructed using the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM. EDS elemental energy dispersive spectroscopy is then used to obtain the distribution and proportion of each element. Finally, software quantitative analysis is used to obtain the pore distribution, volume distribution, and mass distribution of each component. Combined with parameters such as the total mass, total volume, and total thickness of the sample, values ​​for porosity, pore size, mass, volume, and thickness can be obtained. The above parameters can be tested and analyzed using the FEI Scios 2HiVac instrument. The above testing method can also be used to test porous network membranes of organic polymers that have not yet been combined with electrolyte materials.

[0196] Other detection and analysis methods for the location, structure, particle composition and distribution, and elemental composition and distribution of the first electrolyte layer, the second electrolyte layer, and the organic polymer porous mesh membrane: The cross-section of the composite membrane material can be obtained by argon ion polishing technology (CP cross-section polishing technology). Further, the location, structure, particle composition and distribution, and elemental composition and distribution of the first electrolyte layer, the second electrolyte layer, and the organic polymer porous mesh membrane in the composite membrane can be characterized by SEM-EDS.

[0197] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0198] (a1) Through holes include through holes; optionally, at least 80% of the through holes are through holes; further optionally, the through holes are through holes.

[0199] (a2) The ionic conductivity of the composite electrolyte layer is greater than or equal to 1 mS / cm under at least one temperature condition between 25℃ and 60℃; optionally, the ionic conductivity of the composite electrolyte layer at 25℃ is greater than or equal to 1 mS / cm.

[0200] (a3) The side of the through hole near the positive electrode layer is filled with a halide solid electrolyte, and the side of the through hole near the negative electrode layer is filled with a sulfide solid electrolyte.

[0201] (a4) The average diameter of the through-hole is 1 μm to 200 μm, and can be selected as 5 μm to 100 μm, based on the dimension perpendicular to the thickness direction of the porous network membrane of the organic polymer;

[0202] (a5) In terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film, the diameter of the through hole at different thickness positions of the organic polymer porous mesh film ranges from 1 μm to 200 μm, and can be selected from 5 μm to 100 μm.

[0203] (b1) The organic polymer porous mesh membrane includes one or more of polyolefin fibers, polyamide fibers and polyester fibers; optionally, the organic polymer porous mesh membrane includes one or more of nylon fibers, polypropylene fibers and polyester fibers;

[0204] (b2) The organic polymer porous mesh membrane includes polymer fibers, optionally, the thermal decomposition temperature of the polymer fibers is greater than or equal to 240°C, optionally 200°C to 800°C;

[0205] (b3) The mass percentage of the halide solid electrolyte in the first electrolyte layer is 80% to 100%, and can be selected as 90% to 100%;

[0206] (b4) The mass percentage of the sulfide solid electrolyte in the second electrolyte layer is 80% to 100%, and can be selected as 90% to 100%;

[0207] (c1) The tensile strength of the organic polymer porous mesh membrane or composite electrolyte layer is greater than or equal to 1 MPa, and optionally, is greater than or equal to 10 MPa.

[0208] (c2) The tortuosity of the organic polymer porous network membrane is 1 to 10, and can be selected as 1 to 3;

[0209] (c3) The porosity of the organic polymer porous mesh membrane is 50% to 90%, and can be selected as 50% to 80%.

[0210] In some embodiments, in the porous mesh membrane of the organic polymer, the through-holes include through-holes. Non-limitingly, the number of through-holes in the through-holes can be greater than or equal to 80%. Non-limitingly, the number of through-holes in the through-holes can be any of the following percentages, or greater than or equal to any of the following percentages, or greater than or equal to any of the following percentages and less than or equal to 100%, or selected from a range consisting of any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 94%, 95%, 96%, 98%, 99%, etc.

[0211] In some implementations, at least 80% of the through holes are straight through holes.

[0212] In some implementations, the through hole is a straight through hole.

[0213] In this application, unless otherwise specified, a "through-hole" in an organic polymer porous mesh membrane refers to a through-hole in which at least a portion can extend from the first surface to the second surface in a straight line along the thickness direction of the organic polymer porous mesh membrane. In this case, when the through-hole is projected along the thickness direction of the organic polymer porous mesh membrane, a blank area corresponding to the through portion exists at the center of the projected area. The tortuosity of this through portion is 1.

[0214] By setting at least a portion of the through-holes as through-holes, better connectivity between the first and second electrolyte layers can be achieved, which is beneficial for the composite electrolyte layer to provide higher ionic conductivity, thus improving the cycle life of the solid-state battery. Furthermore, it is more conducive to maximizing the capacity of the negative electrode and improving the initial coulombic efficiency of the solid-state battery. Setting a higher number of through-holes (e.g., at least 80%) within the through-holes further enhances the ionic conductivity of the composite electrolyte layer.

[0215] In some embodiments, the composite electrolyte layer exhibits an ionic conductivity greater than or equal to 1 mS / cm at at least one temperature condition between 25°C and 60°C. In some of these embodiments, the composite electrolyte layer exhibits an ionic conductivity greater than or equal to 1 mS / cm at 25°C.

[0216] In this application, "ionic conductivity" has a well-known meaning in the art, and the ionic conductivity of the composite electrolyte layer can be obtained by using conventional testing methods in the art. The "25°C ionic conductivity" of the composite electrolyte layer refers to the ionic conductivity measured at a test temperature of 25°C.

[0217] In this application, the ionic conductivity of the composite electrolyte layer can be tested using the following method: Disassemble the battery, remove the solid-state cell, remove the positive and negative electrode layers to obtain the composite electrolyte membrane corresponding to the composite electrolyte layer, which serves as the membrane to be tested; place the membrane to be tested into a mold sleeve, apply pressure (e.g., to 350 MPa), and perform alternating current impedance spectroscopy (EIS) using an impedance analyzer; calculate the ionic conductivity of the membrane to be tested based on the impedance value. The testing method can be referred to in the following embodiment section.

[0218] In this application, the test temperature for the ionic conductivity of the composite electrolyte layer can be one of the following conditions: 25℃ to 60℃, such as 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, etc. Unless otherwise specified, 25℃ can be used.

[0219] By ensuring that the ionic conductivity of the composite electrolyte layer is greater than or equal to 1 mS / cm at at least one temperature condition (e.g., 25°C) between 25°C and 60°C, it is beneficial to improve the cycle life of solid-state batteries and the initial coulombic efficiency.

[0220] In some embodiments, the side of the through-hole closest to the positive electrode layer is filled with a halide solid electrolyte, and the side of the through-hole closest to the negative electrode layer is filled with a sulfide solid electrolyte.

[0221] It is understood that the first electrolyte layer and the second electrolyte layer in the composite electrolyte layer are connected. Furthermore, the side of the through-hole closest to the positive electrode layer can be filled with a halide solid electrolyte, and the side of the through-hole closest to the negative electrode layer can be filled with a sulfide solid electrolyte. This helps to improve the uniformity of ionic conductivity distribution in the composite electrolyte layer, reduce polarization in the composite electrolyte film, and better improve the cycle life of the solid-state battery.

[0222] In some embodiments, the average diameter of the through-holes, measured in terms of the dimension perpendicular to the thickness direction of the porous organic polymer membrane, is 1 μm to 200 μm, optionally 1 μm to 100 μm, further optionally 5 μm to 100 μm, and may also be any of the following values ​​or a range selected from any two of the following values: 1 μm, 2 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 150 μm, 160 μm, 180 μm, 200 μm, etc.

[0223] In some embodiments, the diameter of the through-holes at different thickness locations of the organic polymer porous mesh film, measured perpendicular to the thickness direction of the membrane, ranges from 1 μm to 200 μm, optionally from 1 μm to 100 μm, further optionally from 5 μm to 100 μm, and may also be any of the following values ​​or a range selected from any two of the following values: 1 μm, 2 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 150 μm, 160 μm, 180 μm, 200 μm, etc.

[0224] In this application, unless otherwise specified, the thickness direction of the "organic polymer porous mesh membrane" can be referred to as the longitudinal direction, which also corresponds to the thickness direction of the composite electrolyte layer.

[0225] In this application, unless otherwise specified, "average diameter of the through-hole" refers to the average diameter of the through-hole at different thickness positions in the organic polymer porous mesh membrane, measured in terms of the dimension perpendicular to the thickness direction (i.e., the dimension perpendicular to the longitudinal direction). Regarding "diameter of the through-hole at a certain thickness position in the organic polymer porous mesh membrane," this refers to the maximum diameter of all directions at that thickness position. The through-hole can be projected longitudinally along the thickness position, and the maximum diameter among the diameters of the projected outline is the diameter of the through-hole at that thickness position.

[0226] The following method can be used for testing: Using an organic polymer porous mesh membrane or composite electrolyte membrane as the sample, the three-dimensional structure of the sample is reconstructed using the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM. EDS elemental energy dispersive spectroscopy is then used to obtain the elemental distribution, confirming the contour boundaries of the through-holes at different thicknesses. Several through-holes are selected, and their average diameter (D) at different thicknesses is measured. x ), to make several through holes D x The average value is taken as the "average diameter of the through-hole". Several through-holes are selected, and their diameter ranges at different thickness locations are measured. The range formed by the minimum and maximum boundary values ​​of each diameter range of the several through-holes is taken as the "diameter range of the through-hole at different thickness locations in the organic polymer porous mesh membrane". The number of through-holes sampled can be greater than or equal to 6 or more, such as at least 10 or at least 20. For the selected through-hole to be tested, the diameter of the through-hole is measured at multiple thickness locations along the longitudinal direction. The average value of the diameter test values ​​at multiple thickness locations is taken as the D of the through-hole. xThe range of diameter test values ​​at multiple thickness locations is defined as the "diameter range of the through-hole at different thickness locations in the organic polymer porous mesh membrane". These multiple thickness locations can be relatively uniformly distributed longitudinally. For a selected through-hole to be tested, unless otherwise specified, the diameter (D) of the through-hole is obtained. x At least six thickness locations should be measured to obtain the diameter range of the through-hole at different thickness locations in the organic polymer porous mesh membrane. At least 10 locations should be measured, and at least more locations, such as at least 20 locations, can also be measured, but this is not limited to. The more locations measured, the more accurate the test results.

[0227] By controlling the average diameter of the through holes and the diameter range of the through holes at different thickness positions of the organic polymer porous mesh film within the aforementioned range, it is beneficial to maintain the good flexibility and mechanical strength of the organic polymer porous mesh film, and it is also more beneficial to embed the first electrolyte layer and the second electrolyte layer, and to improve the ionic conductivity of the composite electrolyte layer.

[0228] Non-limiting examples of organic polymer porous mesh membranes may include one or more of polyolefin fibers, polyamide fibers, and polyester fibers. Non-limiting examples of polyolefin fibers may include polypropylene fibers. Non-limiting examples of polyamide fibers may include nylon fibers. Non-limiting examples of polyester fibers may include polyethylene terephthalate (PEG). Non-limiting examples of organic polymer porous mesh membranes may include one or more of nylon fibers, polypropylene fibers, and polyester fibers.

[0229] In some embodiments, the organic polymer porous mesh membrane comprises polymer fibers. Non-limitingly, the thermal decomposition temperature of the polymer fibers is greater than or equal to 200°C, optionally between 200°C and 800°C, and may also be any of the following temperatures, or greater than or equal to any of the following temperatures, or greater than or equal to any of the following temperatures and less than or equal to 800°C, or selected from any two of the following temperature ranges: 200°C, 220°C, 240°C, 250°C, 260°C, 280°C, 300°C, 320°C, 350°C, 360°C, 380°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 760°C, 780°C, etc.

[0230] In this application, "thermal decomposition temperature" has a well-known meaning in the art, referring to the temperature at which a material begins to decompose during heating, and can be used to characterize the thermal stability of the material. The thermal decomposition temperature of polymer fibers can be obtained using known instruments and methods suitable for testing the thermal decomposition temperature of polymer materials. Methods such as thermogravimetric analysis (TGA), differential thermal analysis, and thermomechanical curve analysis can be used.

[0231] Unless otherwise specified, the thermal decomposition temperature of polymer fibers can be determined by thermogravimetric analysis (TGA). An exemplary procedure is as follows: Weigh 5 mg to 20 mg of the dried sample to be tested into an alumina crucible, place it on the sample stage of a thermogravimetric analyzer (such as a Mettler-Toledo TGA-2), set the test temperature range to 20 °C to 550 °C, and the heating rate to 10 °C / min. Record the temperature Tn at which 5% thermal weight loss occurs as the thermal decomposition temperature of the sample.

[0232] Organic polymer porous mesh membranes allow for flexible selection of more suitable polymer materials, achieving higher mechanical strength and better flexibility while further improving the performance of the organic polymer porous mesh membrane, thereby achieving better cycle life of solid-state batteries. For example, by controlling the thermal decomposition temperature of the polymer fibers in the organic polymer porous mesh membrane within the aforementioned range, it is beneficial to make the polymer fibers more suitable for the processing technology of organic polymer porous mesh membranes and solid-state batteries.

[0233] In some embodiments, the organic polymer porous mesh membrane includes a bio-based polymer fiber material. Optionally, the thermal decomposition temperature of the bio-based polymer fiber material is greater than or equal to 200°C, can be selected from 200°C to 800°C, or can be any of the following temperatures, or greater than or equal to any of the following temperatures, or greater than or equal to any of the following temperatures and less than or equal to 800°C, or selected from any two of the following temperature ranges: 200°C, 220°C, 240°C, 250°C, 260°C, 280°C, 300°C, 320°C, 350°C, 360°C, 380°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 760°C, 780°C, etc.

[0234] In some embodiments, the mass percentage (which may be denoted as F1) of the halide solid electrolyte in the first electrolyte layer may be 80% to 100%, optionally 90% to 100%, or may be any of the following percentages followed by a range of any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 98%, 99%, 100%, etc.

[0235] In some embodiments, the mass percentage (which may be denoted as F2) of the sulfide solid electrolyte in the second electrolyte layer can be 80% to 100%, optionally 90% to 100%, or any of the following percentages followed by a range of any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 98%, 99%, 100%, etc.

[0236] In some embodiments, both F1 and F2 are 100%. In this case, the first solid electrolyte is a halide solid electrolyte, and the second solid electrolyte is a sulfide solid electrolyte.

[0237] By controlling one or both of the following parameters within the aforementioned ranges: the mass percentage of halide solid electrolyte in the first electrolyte layer (F1) and the mass percentage of sulfide solid electrolyte in the second electrolyte layer (F2), it is beneficial to obtain a higher ionic conductivity for the composite electrolyte layer.

[0238] In some embodiments, the tensile strength of the organic polymer porous mesh membrane may be greater than or equal to 1 MPa, optionally greater than or equal to 10 MPa, further optionally greater than or equal to 15 MPa, and even more optionally greater than or equal to 20 MPa. It may also be any of the following strengths, or greater than or equal to any of the following strengths, or selected from any two of the following strengths: 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 10 MPa, 12 MPa, 15 MPa, 16 MPa, 18 MPa, 20 MPa, 22 MPa, 23 MPa, 24 MPa, etc.

[0239] In some embodiments, the tensile strength of the composite electrolyte layer can be greater than or equal to 1 MPa, optionally greater than or equal to 10 MPa, or can be any of the following strengths, or greater than or equal to any of the following strengths, or selected from any two of the following strengths: 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 10 MPa, 12 MPa, 15 MPa, etc.

[0240] In this application, "tensile strength" has a well-known meaning in the art and can be obtained by testing with instruments and methods suitable for use in the art. A tensile testing machine (such as an Instron 3365 tensile testing machine) can be used. The test sample can be a strip-shaped specimen with a width (W) of 20 mm and a length (L) greater than or equal to 60 mm. The measured value of the specimen thickness is recorded as D, and the cross-sectional area of ​​the specimen is A = W × D. The initial distance between the clamps is set to 40 ± 5 mm. Test procedure: Place both ends of the specimen into the upper and lower ends of the clamps in sequence, clamp the clamps, and ensure that the specimen and the clamps are in the same vertical direction, and that the force is uniform with no obvious tensile deformation. After preparation, perform a tensile test at a rate of 10 mm / min until the specimen breaks and the tensile test is stopped. Record the maximum tensile force F that the specimen bears when it breaks. The tensile strength (T) of the test sample is then calculated using the following formula: T = F / A.

[0241] The test sample for the organic polymer porous network membrane in a solid-state battery can be obtained by the following method: disassemble the battery, remove the solid-state cell, remove the positive and negative electrode layers to obtain the composite electrolyte membrane material corresponding to the composite electrolyte layer, swell the composite electrolyte membrane material in a solvent (such as anhydrous ethanol), and then repeatedly rinse it with anhydrous ethanol to remove the filling medium to obtain the polymer network, which can be used as the test sample for the organic polymer porous network membrane. Furthermore, the tensile strength obtained by tensile testing the composite electrolyte membrane material can be used as the test value for the "tensile strength of the composite electrolyte layer".

[0242] By controlling the tensile strength of the porous organic polymer membrane within the aforementioned range, it is possible to provide higher mechanical strength and improve processability during the preparation of the composite electrolyte membrane. Furthermore, the composite electrolyte layer in the solid-state battery can provide better flexibility, higher structural stability, and more stable positive and negative electrode interface contact, thus better balancing the improvement of the cycle life of the solid-state battery and the large-scale preparation of the composite electrolyte membrane.

[0243] In some embodiments, the tortuosity of the organic polymer porous mesh membrane is 1 to 10, which can be selected as 1 to 3, or any of the following values ​​or a range selected from any two of the following values: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0244] In this application, the "torsionalism (τ)" of the organic polymer porous mesh membrane refers to the tortuosity of its through-pores, reflecting the degree of tortuosity of the connecting pathway from the first surface to the second surface. The smaller the tortuosity, the shorter the connecting pathway. "Torsionalism" is a dimensionless parameter. The theoretical minimum value of tortuosity is 1, at which point the pore connecting pathway is a straight through-pore. Unless otherwise specified, the "torsionalism (τ)" of the organic polymer porous mesh membrane can be defined as: the length of the line connecting the centers of the through-pores at different thickness positions of the organic polymer porous mesh membrane (L... A The ratio τ = L to the thickness (L0) of the porous organic polymer membrane A / L0. The tortuosity (τ) of the porous organic polymer membrane can be obtained by the following method: Using the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM, the three-dimensional structure of the sample is reconstructed, and the elemental distribution is obtained by EDS elemental energy dispersive spectroscopy to confirm the contour boundaries of the through-holes at different thicknesses; several through-holes are selected, the tortuosity of each through-hole is calculated, and then the average value is taken; the number of through-holes sampled can be greater than or equal to 6 or more, such as 10 or 20. The tortuosity of the selected through-holes can be obtained by the following method: For each through-hole, the center of the hole is determined at 10 μm intervals along the longitudinal direction; the centers of the holes at different thicknesses are connected, and the length L is measured. A .

[0245] In some embodiments, the porosity of the organic polymer porous mesh membrane is 50% to 90%, optionally 50% to 80%, and may also be any of the following percentages or a range selected from any two of the following percentages: 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, etc.

[0246] In this application, unless otherwise specified, the "porosity" of an organic polymer porous mesh membrane refers to the percentage of pore volume to total volume, and can be expressed as a percentage. The "porosity" of an organic polymer porous mesh membrane can be denoted as ε.

[0247] Unless otherwise specified in this application, the "porosity" of the organic polymer porous network membrane can be obtained by further calculating the apparent density and true density of the material using a true density meter. In this application, the "porosity" of the organic polymer porous network membrane can also be obtained by software quantitative analysis based on the three-dimensional structure of the sample obtained through layer-by-layer cutting and reconstruction using FIB-SEM coupled with EDS elemental energy dispersive spectroscopy analysis results.

[0248] By controlling one or both of the tortuosity and porosity of the organic polymer porous mesh membrane within the aforementioned range, it is beneficial to provide better ion transport channels. This not only provides a better connection between the first and second electrolyte layers but also allows the organic polymer porous mesh membrane to provide better support and flexibility, thus balancing good ionic conductivity, good flexibility, and high structural stability of the composite electrolyte layer. Furthermore, it can better balance good ionic conductivity and high mechanical strength of the composite electrolyte membrane. The lower the tortuosity of the organic polymer porous mesh membrane, the more beneficial it is to improving the ion conductivity of the composite electrolyte layer.

[0249] It is understandable that the composite electrolyte layer can have better overall performance by adjusting one or more parameters of the organic polymer porous mesh membrane, such as tensile strength, tortuosity, and porosity, in order to better improve the cycle life of solid-state batteries.

[0250] It is understandable that by adjusting one or more parameters of the tensile strength, tortuosity, and porosity of the organic polymer porous mesh membrane, the composite electrolyte layer can have better overall performance, so as to better balance the improvement of the cycle life of solid-state batteries and the large-scale preparation of composite electrolyte membranes.

[0251] It is understood that the overall performance of the composite electrolyte layer can be optimized by adjusting one or more of the aforementioned features (a1) to (a5), (b1) to (b4), (c1) to (c3) and optional features within the aforementioned feature range, so as to better improve the cycle life of solid-state batteries, or better balance the improvement of the cycle life of solid-state batteries and the large-scale preparation of composite electrolyte membranes.

[0252] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0253] (d1) The thickness of the first electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer, and can be selected as 45% to 55%;

[0254] (d2) The thickness of the second electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer, and can be selected as 45% to 55%;

[0255] (d3) The thickness of the organic polymer porous mesh membrane is 60% to 100% of the thickness of the composite electrolyte layer, and can be selected as 80% to 100%;

[0256] (d4) The thickness of the organic polymer porous mesh membrane is greater than or equal to 10 μm, and can be selected from 10 μm to 150 μm;

[0257] (d5) The organic polymer porous mesh membrane accounts for 5% to 30% of the mass of the composite electrolyte layer, and can be selected as 5% to 20%;

[0258] (d6) The mass percentage of halide solid electrolyte in the composite electrolyte layer is 5% to 90%, and can be selected as 40% to 60%;

[0259] (d7) The mass percentage of sulfide solid electrolyte in the composite electrolyte layer is 5% to 90%, and can be selected as 40% to 60%;

[0260] (d8) The composite electrolyte layer includes a fibrous polymer binder, the fibrous polymer binder having a mass percentage of 0.1% to 5% in the composite electrolyte layer, optionally 1% to 5%.

[0261] Non-limiting, the percentage of the thickness of the first electrolyte layer relative to the thickness of the composite electrolyte layer (F H1 The percentage can be 25% to 75%, or 45% to 55%, or any of the following percentages or a range of any two of the following percentages: 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, etc.

[0262] Non-limiting, the percentage of the thickness of the second electrolyte layer relative to the thickness of the composite electrolyte layer (F H2The percentage can be 25% to 75%, or 45% to 55%, or any of the following percentages or a range of any two of the following percentages: 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, etc.

[0263] Non-limiting, the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F H0 The percentage can be 60% to 100%, optionally 80% to 100%, further optionally 80% to 95%, or any of the following percentages or a range consisting of any two of the following percentages: 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc.

[0264] Non-limitingly, the thickness (D0) of the organic polymer porous mesh membrane can be greater than or equal to 10 μm, and can be selected from 10 μm to 150 μm. It can also be any of the following thicknesses, or a range selected from any two of the following thicknesses: 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, etc.

[0265] Non-limiting, the mass percentage (F) of the organic polymer porous network membrane in the composite electrolyte layer. M0 The percentage can be 5% to 30%, or 5% to 20%, or any of the following percentages or a range consisting of any two of the following percentages: 5%, 10%, 15%, 20%, 25%, 30%, etc.

[0266] Without limitation, the mass percentage (F) of the halide solid electrolyte in the composite electrolyte layer. M1 The percentage can be 5% to 90%, or 40% to 60%, or any of the following percentages or a range consisting of any two of the following percentages: 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, etc.

[0267] Without limitation, the mass percentage (F) of the sulfide solid electrolyte in the composite electrolyte layer. M2 The percentage can be 5% to 90%, or 40% to 60%, or any of the following percentages or a range of any two of the following percentages: 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, etc.

[0268] In some embodiments, the composite electrolyte layer includes a fibrous polymer binder. Non-limitingly, the fibrous polymer binder may constitute 0.1% to 5% by mass in the composite electrolyte layer, optionally 1% to 5%, further optionally 1% to 2%, and may also be any of the following percentages or a range selected from any two of the following percentages: 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0269] In some embodiments, at least one of the first electrolyte layer and the second electrolyte layer includes a fibrous polymer binder. The fibrous polymer binder located in the first electrolyte layer may be referred to as the "first fibrous polymer binder," and the fibrous polymer binder located in the second electrolyte layer may be referred to as the "second fibrous polymer binder."

[0270] In some embodiments, the fiber compound binder includes one or more of a first fiberized polymer binder and a second fiberized polymer binder.

[0271] By using the percentage of the thickness of the first electrolyte layer relative to the thickness of the composite electrolyte layer (F) H1 The percentage of the thickness of the second electrolyte layer relative to the thickness of the composite electrolyte layer (F) H2 The percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F) H0 ), the thickness (D0) of the organic polymer porous mesh membrane, and the mass percentage (F) of the organic polymer porous mesh membrane in the composite electrolyte layer. M0 ), the mass percentage of halide solid electrolytes in the composite electrolyte layer (F) M1 ), the mass percentage of sulfide solid electrolyte in the composite electrolyte layer (F) M2 Controlling one or more parameters of the mass ratio of the optional fibrous polymer binder in the composite electrolyte layer within the aforementioned range is beneficial for better balancing the synergistic effects of the first electrolyte layer, the second electrolyte layer, and the organic polymer porous mesh membrane, and for better leveraging the multiple functions of the composite electrolyte layer. This allows the composite electrolyte layer to better provide good positive and negative electrode chemical interface stability, good ionic conductivity, good flexibility, high structural stability, and more stable positive and negative electrode interface contact, thereby significantly extending the cycle life of the solid-state battery.

[0272] For example, by the mass percentage (F) of the halide solid electrolyte in the composite electrolyte layer... M1 ), the mass percentage of sulfide solid electrolyte in the composite electrolyte layer (F) M2By controlling one or more parameters of the optional fibrous polymer binder in the composite electrolyte layer within the aforementioned range, the content of solid electrolyte with high ionic conductivity in the composite electrolyte layer can be controlled within a more suitable range, thereby providing higher ionic conductivity to the composite electrolyte layer, while also taking into account good flexibility, high structural stability and more stable positive and negative electrode interface contact.

[0273] In some embodiments, the thickness (D0) of the organic polymer porous mesh film is 30 μm to 150 μm, optionally 30 μm to 150 μm, more preferably 50 μm to 150 μm, and the percentage of the thickness of the organic polymer porous mesh film relative to the thickness of the composite electrolyte layer is 80% to 100%, optionally greater than or equal to 80% and less than 100%, more preferably 80% to 95%; non-limitingly, the thickness of the organic polymer porous mesh film can be any of the following thicknesses, or a range selected from any two of the following thicknesses: 30 μm, 35 μm, 40μm, 45μm, 50μm, 55μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, etc.; non-limitingly, the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer can be any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 97%, 98%, 99%, etc.

[0274] By controlling the thickness of the organic polymer porous mesh film and the percentage of the organic polymer porous mesh film thickness relative to the thickness of the composite electrolyte layer within the aforementioned range, it is beneficial to reduce the risk of internal short circuits and improve the reliability of solid-state batteries.

[0275] In some embodiments, the thickness (D0) of the organic polymer porous network membrane can be 10 μm to 30 μm, or any of the following thicknesses, or a range selected from any two of the following thicknesses: 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc. This allows the thickness of the composite electrolyte membrane to be controlled within a relatively thin range, which is beneficial for reducing the weight of the solid-state battery, increasing its energy density, reducing internal resistance, improving rate performance, and lowering costs.

[0276] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0277] (t1) The thickness of the organic polymer porous mesh membrane is greater than or equal to 60% and less than 100% of the thickness of the composite electrolyte layer, optionally greater than or equal to 80% and less than 100%, and further optionally 80% to 95%.

[0278] (t2) At least one of the first electrolyte layer and the second electrolyte layer includes a portion located outside the porous organic polymer membrane; optionally, both the first electrolyte layer and the second electrolyte layer include a portion located outside the porous organic polymer membrane.

[0279] In some embodiments, the thickness of the organic polymer porous mesh membrane is a percentage (F) of the thickness of the composite electrolyte layer. M0 It can be greater than or equal to 60% and less than 100%, optionally greater than or equal to 80% and less than 100%, further optionally 80% to 95%, and can also be any of the following percentages, or greater than or equal to any of the following percentages and less than 100%, or a range selected from any two of the following percentages: 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, etc.

[0280] By using the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F... M0 Keeping the battery within the aforementioned range is beneficial for improving battery cycle life while also taking into account flexibility and battery internal resistance.

[0281] When the percentage of the thickness of the organic polymer porous mesh film relative to the thickness of the composite electrolyte layer is less than 100%, at least one of the first electrolyte layer and the second electrolyte layer includes a portion located outside the organic polymer porous mesh film, which is more conducive to improving the electrical contact with the adjacent electrode layer.

[0282] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0283] (e1) Maximum particle size of halide solid electrolyte in the first electrolyte layer, D v 99 or with an average particle size of 1μm to 50μm, optionally 1μm to 10μm;

[0284] (e2) Maximum particle size of sulfide solid electrolyte in the second electrolyte layer, D v 99 or with an average particle size of 1μm to 50μm, or 1μm to 10μm.

[0285] In some embodiments, the maximum particle size (which may be denoted as Dmax1) of the halide solid electrolyte in the first electrolyte layer can be 1 μm to 50 μm, or can be 1 μm to 10 μm, or can be any of the following thicknesses, or a range selected from any two of the following thicknesses: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, etc.

[0286] In some embodiments, the maximum particle size (which may be denoted as Dmax2) of the sulfide solid electrolyte in the second electrolyte layer can be 1 μm to 50 μm, or can be 1 μm to 10 μm. It can also be any of the following thicknesses, or a range selected from any two of the following thicknesses: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, etc.

[0287] In some embodiments, the D of the halide solid electrolyte in the first electrolyte layer v 99 (can be written as D) v 991) can be 1μm to 50μm, can be selected from 1μm to 10μm, and can also be any of the following thicknesses, or a range consisting of any two of the following thicknesses: 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 8μm, 10μm, 12μm, 15μm, 20μm, 25μm, 30μm, 40μm, 50μm, etc.

[0288] In some embodiments, the D of the sulfide solid electrolyte in the second electrolyte layer v 99 (can be written as D) v 992) can be 1μm to 50μm, can be selected from 1μm to 10μm, and can also be any of the following thicknesses, or a range consisting of any two of the following thicknesses: 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 8μm, 10μm, 12μm, 15μm, 20μm, 25μm, 30μm, 40μm, 50μm, etc.

[0289] In some embodiments, the average particle size (which may be denoted as Dm1) of the halide solid electrolyte in the first electrolyte layer may be 1 μm to 50 μm, or may be 1 μm to 10 μm, or may be any of the following thicknesses, or a range selected from any two of the following thicknesses: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, etc.

[0290] In some embodiments, the average particle size (which may be denoted as Dm2) of the sulfide solid electrolyte in the second electrolyte layer may be 1 μm to 50 μm, optionally 1 μm to 10 μm, and may also be any of the following thicknesses, or a range selected from any two of the following thicknesses: 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, etc.

[0291] It is understandable that the maximum particle size of the material is greater than D. v 99. Since the maximum particle size is greater than the average particle size, Dmax1 > D. v 991 and Dmax1>Dm1, Dmax2>D v 992 and Dmax2>Dm2.

[0292] It should be noted that after densification, solid electrolyte materials may become ceramic, which changes the particle size and its distribution.

[0293] By using the maximum particle size of the halide solid electrolyte in the first electrolyte layer as D v 99 or average particle size and the maximum particle size of sulfide solid electrolyte in the second electrolyte layer, D v Controlling one or two parameters, such as the average particle size, within the aforementioned range is beneficial for better filling in the composite electrolyte layer and for improving the ionic conductivity of the composite electrolyte layer.

[0294] In this application, in the composite electrolyte layer, the maximum particle size of the halide solid electrolyte in the first electrolyte layer can be denoted as Dmax1, and the maximum particle size of the sulfide solid electrolyte in the second electrolyte layer can be denoted as Dmax2; the average particle size of the halide solid electrolyte in the first electrolyte layer can be denoted as Dm1, and the average particle size of the sulfide solid electrolyte in the second electrolyte layer can be denoted as Dm2; the Dmax1 of the halide solid electrolyte in the first electrolyte layer can be denoted as Dm1, and the average particle size of the sulfide solid electrolyte in the second electrolyte layer can be denoted as Dm2; the average particle size of the halide solid electrolyte in the first electrolyte layer can be denoted as Dm1. v 99 can be written as D v 991, the average particle size of the sulfide solid electrolyte in the second electrolyte layer can be denoted as D. v 992.

[0295] In the context of this application, the volumetric cumulative distribution particle size D can be used. v N (where N represents any value selected from 0 to 100) is used to characterize the particle size of the material, referring to the particle size corresponding to the cumulative volume distribution percentage of the material reaching N%, where the particle size is less than or equal to D. v N's volume percentage is N%. D vN can be obtained from the volumetric cumulative distribution curve of the material particles. Unless otherwise specified, the volumetric cumulative distribution curve is accumulated from zero on the smaller particle size side. Let D... v The example of 99 will be used for illustration. Unless otherwise stated in this application, D... v 99 refers to the particle size corresponding to a cumulative volume distribution percentage of 99% for a material. This parameter indicates that the particle size of 99% of the material's volume is less than or equal to D. v 99, and the particle size of 1% of the material volume is greater than D. v 99. Those skilled in the art will understand D v The meaning of 99.

[0296] Unless otherwise specified in this application, Dmax1, Dmax2, Dm1, Dm2, and D can be obtained by testing using the following method. v 991 and D v 992: Using the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM, the three-dimensional structure of the sample was reconstructed. The distribution of each element was obtained by EDS elemental energy dispersive spectroscopy analysis, and the halide solid electrolyte in the first electrolyte layer and the sulfide solid electrolyte in the second electrolyte layer were identified. Then, the particle size-related parameters were roughly statistically analyzed.

[0297] (1) Test analysis of Dmax1, Dmax2, Dm1 and Dm2.

[0298] Multiple regions (e.g., at least 3 regions, more preferably at least 6 regions) are randomly selected from the first electrolyte layer, and a certain number (e.g., greater than or equal to 50 particles, optionally greater than or equal to 80 particles, more preferably greater than or equal to 100 particles) of halide solid electrolyte are selected to statistically obtain Dmax1 and Dm1. Similarly, multiple regions (e.g., at least 3 regions, more preferably at least 6 regions) are randomly selected from the second electrolyte layer, and a certain number (e.g., greater than or equal to 50 particles, optionally greater than or equal to 80 particles, more preferably greater than or equal to 100 particles) of sulfide solid electrolyte are selected to statistically obtain Dmax2 and Dm2. The volume of any randomly selected region can be greater than or equal to 1 mm. 3 Optionally, it can be greater than or equal to 5mm. 3 .

[0299] (2)D v 991 and D v Test analysis of 992.

[0300] Multiple regions in the first electrolyte layer are randomly selected (e.g., at least 6 regions, or more specifically, at least 10 regions). A certain number of halide solid electrolytes (e.g., greater than or equal to 100 particles, optionally greater than or equal to 150 particles, or more specifically, greater than or equal to 300 particles) are selected. The cumulative volume distribution curve is plotted, and then D is statistically obtained. v 991; Randomly select multiple regions in the second electrolyte layer (e.g., at least 6 regions, or even at least 10 regions), and select a certain number (e.g., greater than or equal to 100 particles, optionally greater than or equal to 150 particles, or even optionally greater than or equal to 300 particles) of sulfide solid electrolyte, plot the volume cumulative distribution curve, and then statistically obtain D. v 991. The volume of any randomly selected region can be greater than or equal to 1 mm. 3 Optionally, it can be greater than or equal to 5mm. 3 .

[0301] In some embodiments, the ionic conductivity of the composite electrolyte layer at at least one temperature condition between 25°C and 60°C can be greater than or equal to 1 mS / cm, optionally between 1 mS / cm and 10 mS / cm, further optionally between 1 mS / cm and 5 mS / cm, and can also be any of the following values, or greater than or equal to any of the following values, or selected from any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0302] In some embodiments, the ionic conductivity of the composite electrolyte layer at 25°C can be greater than or equal to 1 mS / cm, and can be selected from 1 mS / cm to 10 mS / cm, further selected from 1 mS / cm to 5 mS / cm, or can be any of the following values, or greater than or equal to any of the following values, or selected from any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0303] By controlling the ionic conductivity of the composite electrolyte layer within the aforementioned range, it is beneficial to improve the cycle performance of solid-state batteries.

[0304] In some embodiments, the composite electrolyte layer satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0305] (f1) The ionic conductivity of the halide solid electrolyte is greater than or equal to 1 mS / cm under at least one temperature condition from 25°C to 60°C, and can be selected from 1 mS / cm to 10 mS / cm; optionally, the ionic conductivity of the halide solid electrolyte at 25°C is greater than or equal to 1 mS / cm, and can be selected from 1 mS / cm to 10 mS / cm.

[0306] (f2) Halide solid electrolytes include any one or more of LiInCl, Li3YBr6 or Li3YCl6;

[0307] (f3) Sulfide solid electrolytes include one or more of the following: silver sulfide-germanium sulfide type sulfide electrolytes, LGPS type sulfide electrolytes, and lithium sulfide-phosphorus pentasulfide complex type sulfide electrolytes;

[0308] (f4) The ionic conductivity of the sulfide solid electrolyte is 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C; optionally, the ionic conductivity of the sulfide solid electrolyte is 1 mS / cm to 10 mS / cm at 25°C.

[0309] (f5) The first electrolyte layer includes a first fibrous polymer binder; the first fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin has a mass percentage of 0.1% to 5% in the first electrolyte layer, optionally 1% to 5%, and further optionally 1% to 2%; optionally, the first fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride;

[0310] (f6) The second electrolyte layer includes a second fibrous polymer binder; the second fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin in the second electrolyte layer is 0.1% to 5% by mass, optionally 1% to 5%, and further optionally 1% to 2%; optionally, the second fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer and polyvinylidene fluoride.

[0311] The composite electrolyte layer allows for flexible selection of more suitable halide solid electrolytes, sulfide solid electrolytes, binders in the first electrolyte layer, and binders in the second electrolyte layer, in order to better improve the cycle performance of solid-state batteries.

[0312] In some embodiments, the ionic conductivity of the halide solid electrolyte in the first electrolyte layer is greater than or equal to 1 mS / cm at at least one temperature condition between 25°C and 60°C, and can be selected from 1 mS / cm to 10 mS / cm, or more preferably from 1 mS / cm to 5 mS / cm. It can also be any of the following values, or greater than or equal to any of the following values, or selected from a range consisting of any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0313] In some embodiments, the ionic conductivity of the halide solid electrolyte in the first electrolyte layer at 25°C is greater than or equal to 1 mS / cm, and can be selected from 1 mS / cm to 10 mS / cm, further selected from 1 mS / cm to 5 mS / cm, or can be any of the following values, or greater than or equal to any of the following values, or selected from any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0314] The ionic conductivity of the first electrolyte, the second electrolyte, the halide solid electrolyte in the first electrolyte layer, and the sulfide solid electrolyte in the second electrolyte layer can be controlled by selecting appropriate electrolyte raw materials.

[0315] In this application, the ionic conductivity of the electrolyte raw material (such as a first electrolyte, a second electrolyte, a halide solid electrolyte, or a sulfide solid electrolyte) can be determined by pressing the electrolyte raw material into a membrane, and then testing it using an impedance analyzer via electrochemical impedance spectroscopy (EIS). The ionic conductivity of the membrane under test is calculated based on the impedance value and used as the ionic conductivity of the electrolyte raw material. The membrane can be pressed using the following method: the powder to be tested is poured into a 10 mm diameter tablet mold, and the powder is pressed into a dense membrane at 360 MPa.

[0316] Without limitation, the halide solid electrolyte in the first electrolyte layer may include any one or more of LiInCl, Li3YBr6, or Li3YCl6.

[0317] Without limitation, the sulfide solid electrolyte in the second electrolyte layer may include one or more of the following: silver sulfide-germanium sulfide type sulfide electrolyte, LGPS type sulfide electrolyte, lithium sulfide pentaphosphate disulfide complex type sulfide electrolyte, etc.

[0318] Unless otherwise specified, the sulfide electrolyte of the sulfide type has a sulfide-germanium type crystal phase structure. Without limitation, the sulfide electrolyte of the sulfide type may include compounds with the chemical formula Li.6±s P 1-j A j S 5±s-t B t X 1±s The sulfide electrolyte of [element], where 0 ≤ j < 1, 0 ≤ t < 1, 0 ≤ s < 1. A can be selected from one or more elements including but not limited to Ge, Si, Sn, and Sb. B can be one or more elements of O, Se, and Te. X can be selected from one or more elements of Cl, Br, I, and F. In some embodiments, X is a halogen. Further, X can be selected from one or more elements of Cl, Br, I, and F.

[0319] Unless otherwise specified, the LGPS-based sulfide electrolyte has a LGPS-type crystal phase structure. Without limitation, the LGPS-based sulfide electrolyte can include a sulfide electrolyte with the chemical formula Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w The sulfide electrolyte of [element], where 0 ≤ δ5 < 1, 0 ≤ g ≤ 1, 0 ≤ q ≤ 2, 0 ≤ w < 1. G is selected from one or two elements of Si and Sn. Q is Sb. W is selected from one or more elements of O, Se, Te, Cl, Br, I, and F.

[0320] Without limitation, the lithium sulfide - phosphorus pentasulfide complex - based sulfide electrolyte can include a sulfide electrolyte with the chemical formula (100 - u - v)Li2S·uP2S5·vM m N n The sulfide electrolyte of [element], where 0 < u < 100, 0 ≤ v < 100, 0 ≤ u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6. M can be selected from one or more elements including but not limited to Li, B, Ge, Si, Sn, and Sb. N can be selected from one or more elements of S, Se, Te, O, Cl, Br, I, and F.

[0321] Non-limitingly, the sulfide solid electrolyte in the second electrolyte layer may include at least one of a binary sulfide solid system and a ternary sulfide solid system. Non-limitingly, the binary sulfide solid system may include one or more of Li2S-P2S5, Li2S-SiS2, Li2S-GeS2, and Li2S-B2S3. Non-limitingly, the ternary sulfide solid system may include one or more of the following: silver sulfide-germanium sulfide electrolyte, Li2S-MeS2-P2S5 ternary sulfide electrolyte, lithium germanium phosphorus sulfide electrolyte, Li2S-P2S5-MS ternary sulfide electrolyte, Li2S-P2S5-MCl ternary sulfide electrolyte, and thio-LISICON type sulfide electrolyte; wherein, Me may include one or more elements selected from silicon (Si), germanium (Ge), tin (Sn), and aluminum (Al), and may further be selected from one or more elements selected from Si, Ge, Sn, and Al; M may include one or more elements selected from Ge, Al, Sn, lead (Pb), antimony (Sb), Si, and arsenic (As), and may further be selected from one or more elements selected from Ge, Al, Sn, Pb, Sb, Si, and As.

[0322] In some embodiments, the sulfide solid electrolyte in the second electrolyte layer has an ionic conductivity greater than or equal to 1 mS / cm at at least one temperature condition between 25°C and 60°C, which can be selected as 1 mS / cm to 10 mS / cm, further selected as 1 mS / cm to 5 mS / cm, or any of the following values, or greater than or equal to any of the following values, or selected from any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0323] In some embodiments, the 25°C ionic conductivity of the sulfide solid electrolyte in the second electrolyte layer is greater than or equal to 1 mS / cm, and can be selected from 1 mS / cm to 10 mS / cm, further selected from 1 mS / cm to 5 mS / cm, or can be any of the following values, or greater than or equal to any of the following values, or selected from any two of the following values: 1 mS / cm, 2 mS / cm, 3 mS / cm, 4 mS / cm, 5 mS / cm, 6 mS / cm, 7 mS / cm, 8 mS / cm, 9 mS / cm, 10 mS / cm, etc.

[0324] In some embodiments, the first electrolyte layer includes a first fibrous polymer binder. Non-limitingly, the first fibrous polymer binder may include a fluorinated polyolefin, further wherein the fluorinated polyolefin in the first electrolyte layer may be 0.1% to 5% by mass, optionally 1% to 5%, further optionally 1% to 2%, or may be any of the following percentages or a range selected from any two of the following percentages: 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%. Non-limitingly, the first fibrous polymer binder may include one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride. In this case, the fibrous polymer binder in the composite electrolyte layer includes the first fibrous polymer binder.

[0325] In some embodiments, the second electrolyte layer includes a second fibrous polymer binder. Non-limitingly, the second fibrous polymer binder may include a fluorinated polyolefin, further wherein the fluorinated polyolefin in the second electrolyte layer may be 0.1% to 5% by mass, optionally 1% to 5%, further optionally 1% to 2%, or any of the following percentages or a range selected from any two of the following percentages: 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%. Non-limitingly, the second fibrous polymer binder may include one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride. In this case, the fibrous polymer binder in the composite electrolyte layer includes the second fibrous polymer binder.

[0326] Those skilled in the art can use one or more of the following detection methods, including but not limited to, to identify the type and structure of components in the composite electrolyte layer: Fourier transform infrared (FT-IR) spectroscopy, ultraviolet spectroscopy, and proton nuclear magnetic resonance (NMR) spectroscopy. 1 Methods include 1H NMR, X-ray diffraction (XRD), gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), mass spectrometry, inductively coupled plasma atomic emission spectrometry (ICP), energy dispersive spectroscopy (EDS or EDX), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Non-limitingly, one or more of the following methods can be used to identify and analyze the organic components (such as the constituent materials of the porous organic polymer membrane, binder components) in the composite electrolyte layer: Fourier transform infrared (FT-IR) spectroscopy, ultraviolet spectroscopy, and proton nuclear magnetic resonance (NMR) spectroscopy. 1Methods include ¹H NMR, gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), mass spectrometry, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The sample preparation and testing methods for these methods are known to those skilled in the art, and the test parameters can be appropriately adjusted according to the sample characteristics.

[0327] In some embodiments, the positive electrode layer includes a positive electrode active layer, which includes a positive electrode active material, and the positive electrode active material includes a lithium transition metal oxide-based positive electrode material.

[0328] The appropriate type of positive electrode active material can be placed in the positive electrode layer according to the performance requirements of solid-state batteries. For example, the energy density of solid-state batteries can be improved by setting lithium nickel-based oxide positive electrode materials (lithium nickel cobalt manganese-based oxide positive electrode materials).

[0329] In this application, unless otherwise specified, "lithium transition metal oxide cathode material" refers to a cathode active material containing lithium, transition metal elements, and oxygen. Therefore, lithium transition metal oxide cathode materials include non-lithium metal elements, and these non-lithium metal elements include transition metal elements. Non-limitingly, in lithium transition metal oxide cathode materials, the molar percentage of transition metal elements relative to non-lithium metal elements can be 90% to 100%, and can also be any of the following percentages or a range selected from any two of the following percentages: 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0330] In this application, unless otherwise specified, the definition of lithium transition metal oxide cathode materials encompasses lithium transition metal oxides and their modified forms. Modified lithium transition metal oxides include the lithium transition metal oxide itself and modifying elements. Modifying elements may include one or more of doping elements and coating elements. Modified lithium transition metal oxides still fall within the scope of lithium transition metal oxide cathode materials.

[0331] In this application, unless otherwise specified, "a modified positive electrode active material" includes the positive electrode active material itself and the modifying element. Furthermore, the modifying element may exist as a dopant element, a coating element, or a combination of a dopant element and a coating element. Unless otherwise specified, "a modified positive electrode active material" still falls within the scope of positive electrode active materials.

[0332] The positive electrode active material includes at least a positive electrode active body. The "positive electrode active body" is the fundamental part of the positive electrode active material capable of reversibly extracting and inserting active ions. Non-limitingly, the mass percentage of lithium transition metal oxide positive electrode material in the positive electrode active layer can be 50% to 98%, optionally 70% to 98%, or any of the following percentages or a range selected from any two of the following percentages: 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 98%, etc.

[0333] Non-limitingly, lithium transition metal oxide cathode materials may include, but are not limited to, lithium transition metal oxides known in the art that can be used as cathode active materials in solid-state batteries. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified forms. Non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )wait.

[0334] In this application, unless otherwise specified, "non-lithium metal element" refers to a metal element that is not lithium (Li).

[0335] In some embodiments, lithium transition metal oxide cathode materials have a layered crystal structure.

[0336] In some embodiments, the mass percentage of lithium transition metal oxides in the positive electrode active material is 80% to 100%, optionally 90% to 100%, or any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0337] In some embodiments, lithium transition metal oxide cathode materials include lithium nickel-based oxide cathode materials.

[0338] In some embodiments, the positive electrode active material includes a lithium nickel-based oxide positive electrode material; wherein the lithium nickel-based oxide positive electrode material contains Li, a non-lithium metal element and O, and the non-lithium metal element includes Ni.

[0339] In some embodiments, the lithium nickel-based oxide cathode material satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0340] (i) In lithium nickel-based oxide cathode materials, the atomic molar ratio of Ni to non-lithium metal elements is q1, where 0.5≤q1≤0.98, and optionally, 0.8≤q1≤0.98;

[0341] (ii) The lithium nickel-based oxide cathode material contains Ni and Li elements in an atomic molar ratio of q2:x2, wherein 0.5≤q2≤0.98 and 0.6≤x2≤1.2; optionally, 0.8≤q2≤0.98; optionally, 0.8≤x2≤1.1;

[0342] (iii) The lithium nickel-based oxide cathode material contains Ni and O elements in an atomic molar ratio of q3:x3, wherein 0.5≤q3≤0.98, 1.6≤x3≤2.2; optionally, 1.6≤x3≤2.1, further optionally, 1.8≤x3≤2.06; optionally, 0.8≤q3≤0.98;

[0343] (iv) Lithium nickel-based oxide cathode materials contain the element Co;

[0344] (v) The lithium nickel-based oxide cathode material contains at least one of Mn and Al elements; optionally, the lithium nickel-based oxide cathode material contains Mn element.

[0345] In some embodiments, the positive electrode active material satisfies one or more of the following characteristics (any numerical parameter of the following characteristics may also be selected from any suitable value or range in the context):

[0346] (ti)0.8≤q1≤0.98;

[0347] (tii)0.8≤q2≤0.98;

[0348] (tiii) 0.8 ≤ x² ≤ 1.1;

[0349] (tiv)0.8≤q3≤0.98;

[0350] (tv)1.8≤x3≤2.06;

[0351] (tvi) The positive electrode active material includes lithium nickel cobalt manganese-based oxide positive electrode material. Optionally, the lithium nickel cobalt manganese-based oxide positive electrode material accounts for 80% to 100% of the mass of the positive electrode active material, and optionally 90% to 100%.

[0352] (tvii) The mass percentage of lithium nickel-based oxide cathode materials in the cathode active material is 80% to 100%, and can be selected as 90% to 100%.

[0353] Non-limitingly, in the positive electrode layer of the solid-state battery and in the positive electrode active material used to prepare the solid-state battery, q1, q2, and q3 can each independently be any of the following values, or selected from a range consisting of any two of the following values: 0.8, 0.85, 0.9, 0.92, 0.94, 0.95, 0.96, 0.97, 0.98, etc. q1, q2, and q3 can also each independently be selected from any of the following ranges: 0.5–0.98, 0.6–0.98, 0.8–0.98, etc.

[0354] Non-limitingly, in the positive electrode layer of the solid-state battery, x2 can be any of the following values, or a range selected from any two of the following values: 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, etc. x2 can also be independently selected from any of the following ranges: 0.6–1.2, 0.8–1.1, etc.

[0355] Non-limitingly, in the positive electrode layer of the solid-state battery, x3 can be any of the following values, or a range selected from any two of the following values: 1.6, 1.7, 1.8, 1.9, 2, 2.05, 2.06, 2.08, 2.1, 2.12, 2.14, 2.15, 2.16, 2.18, 2.2, etc. x3 can also be independently selected from any of the following ranges: 1.6–2.2, 1.6–2.1, 1.8–2.06, 1.8–2, etc.

[0356] In this application, unless otherwise specified, "lithium nickel-based oxide cathode material" refers to a lithium transition metal oxide cathode material containing nickel. It is understood that lithium nickel-based oxide cathode materials include lithium, non-lithium metal elements, and oxygen, with the non-lithium metal elements including nickel.

[0357] In some embodiments, the positive electrode active material includes lithium nickel cobalt manganese-based oxide positive electrode materials. Non-limitingly, the mass percentage of the lithium nickel cobalt manganese-based oxide positive electrode material in the positive electrode active material can be 80% to 100%, optionally 90% to 100%, or any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0358] In this application, unless otherwise specified, "lithium nickel cobalt manganese-based oxide cathode material" refers to a lithium transition metal oxide cathode material containing nickel, cobalt, and manganese; it is also a lithium nickel-based oxide cathode material containing cobalt and manganese; and it is also a lithium nickel cobalt-based oxide cathode material containing manganese. It is understood that lithium nickel cobalt manganese-based oxide cathode materials include lithium, non-lithium metal elements, and oxygen, wherein the non-lithium metal elements include nickel, cobalt, and manganese.

[0359] In some embodiments, the lithium composite metal oxide cathode material includes a ternary cathode material, which may be selected as a ternary cathode material. In this application, the "ternary cathode material" is composed of Li, nickel, cobalt, M2, and oxygen; wherein, M2 can be manganese or aluminum. When M2 is manganese (Mn), the ternary cathode material is lithium nickel cobalt manganese oxide, which can be denoted as NCM; when M2 is aluminum (Al), the ternary cathode material is lithium nickel cobalt aluminum oxide, which can be denoted as NCA.

[0360] In some embodiments, the mass percentage of lithium nickel-based oxide cathode material in the cathode active material can be 80% to 100%, optionally 90% to 100%, or any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0361] Taking solid-state batteries with lithium-ion active ions as an example, it is understandable that lithium (Li) is intercalated and deintercalated during the charging and discharging process, and the Li content in the positive electrode layer varies depending on the state of discharge. In the exemplary description of the positive electrode active material in this application, unless otherwise specified, the Li content can be the initial state of the material or a non-initial state after charge-discharge cycles. When the positive electrode active material is applied to the positive electrode layer in a solid-state battery system, the Li content in the positive electrode active material contained in the positive electrode layer usually changes after charge-discharge cycles. The Li content can be measured using atomic molar content, but is not limited to this. Regarding "Li content is the initial state of the material," the initial state of the material refers to the state before the positive electrode layer. It is understood that new materials or substances obtained by appropriate modification based on the listed positive electrode active materials are also within the scope of positive electrode active materials. The aforementioned appropriate modification refers to an acceptable modification method for the positive electrode active material, and non-limiting examples include one or more of coating modification and doping modification. In the exemplary description of the positive electrode active material in this application, the oxygen (O) content is usually a theoretical value. Lattice oxygen release will cause changes in the atomic molar content of oxygen, and the actual O content will fluctuate. The O content can be measured in atomic molar content, but is not limited to this.

[0362] Non-limitingly, in the positive electrode active material used to prepare the positive electrode layer of the solid-state battery, x2 can be any of the following values, or a range selected from any two of the following values: 0.98, 0.99, 1.00, 1.01, 1.02, etc., or any range selected from: 0.98 to 1.02, etc. In some embodiments, x2 is 1.

[0363] Non-limitingly, in the positive electrode active material used to prepare the positive electrode layer of the solid-state battery, x3 can be any of the following values, or a range selected from any two of the following values: 1.96, 1.97, 1.98, 1.99, 2.00, 2.01, 2.02, 2.03, 2.04, etc., or any of the following ranges: 1.96 to 2.04, 1.98 to 2.02, 1.99 to 2.01, etc. In some embodiments, x3 is 2.

[0364] Those skilled in the art can use one or more elemental analysis methods, including but not limited to energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and inductively coupled plasma optical emission spectrometry (ICP), to perform compositional analysis on the positive electrode active material in the positive electrode layer.

[0365] In some implementations, the solid-state battery is an all-solid-state battery.

[0366] In this application, unless otherwise specified, "all-solid-state battery" refers to a solid-state battery in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery, so it can be called "all-solid-state battery".

[0367] In some implementations, the solid-state battery is a lithium-ion secondary battery; in this case, the active ions include lithium ions.

[0368] In some implementations, the solid-state battery is an all-solid-state lithium-ion secondary battery, which is both an all-solid-state battery and a lithium-ion secondary battery.

[0369] A solid-state battery includes at least one solid-state battery cell. A solid-state battery may include one or more solid-state battery cells.

[0370] In this application, unless otherwise specified, "solid-state battery cell" refers to a basic unit capable of converting chemical energy into electrical energy, and all its components are solid-state. In some embodiments, a solid-state battery cell may be an all-solid-state battery cell.

[0371] In this application, unless otherwise specified, "all-solid-state battery cell" refers to a solid-state battery cell in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery cell, so it can be called "all-solid-state battery cell".

[0372] Non-limitingly, a solid-state battery cell (which can be an all-solid-state battery cell) may include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, with the solid electrolyte layer located between the positive and negative electrode layers. During battery charging and discharging, active ions shuttle between the positive and negative electrode layers, inserting and extracting. The solid electrolyte layer serves to conduct ions between the positive and negative electrode layers and also isolates them, thus preventing short circuits between the positive and negative electrodes.

[0373] In some embodiments, the solid-state battery cell 5 includes a solid-state cell 52.

[0374] In some implementations, the solid-state cell is an all-solid-state cell.

[0375] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked sequentially.

[0376] It is understandable that the solid electrolyte layer located between the positive electrode layer and the negative electrode layer includes a composite electrolyte layer.

[0377] In a non-limiting manner, the positive electrode layer, the solid electrolyte layer, and the negative electrode layer can be assembled in a stacked manner, with the solid electrolyte layer placed between the positive electrode layer and the negative electrode layer.

[0378] The following is a description of the positive electrode layer.

[0379] The positive electrode layer can be formed based on a solid electrolyte membrane or provided by a pre-fabricated positive electrode sheet, and can be a positive electrode sheet that is suitable for solid-state batteries in the art. It is understood that the solid electrolyte membrane includes the composite electrolyte layer provided in this application, and can be a composite electrolyte membrane.

[0380] Positive electrode sheets can be prepared using dry or wet methods. For example, they can be dry-pressed into films. Alternatively, they can be wet-coated and dried to form films.

[0381] In some embodiments, the positive electrode layer includes a positive electrode current collector and a positive electrode active layer disposed on at least one surface of the positive electrode current collector.

[0382] Unless otherwise stated, the positive electrode layer in this application includes at least a positive electrode active layer.

[0383] Unless otherwise stated in this application, the positive electrode sheet includes at least a positive active layer.

[0384] Unless otherwise stated in this application, the positive electrode active layer includes at least a positive electrode active material, and usually also includes a positive electrode electrolyte material.

[0385] The types of positive electrode active materials in the positive electrode active layer can be referred to in the context of this application. Optionally, it may also include other types of positive electrode active materials known in the art that can be used in the positive electrode layer of solid-state batteries.

[0386] As a non-limiting example, other types of positive electrode active materials may include one or more of the following: other lithium transition metal oxides, lithium phosphates with an olivine structure, and their respective modifications. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides in positive electrode active materials may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modifications. Non-limiting examples of lithium cobalt oxide may include LiCoO2; non-limiting examples of lithium nickel oxide may include LiNiO2; non-limiting examples of lithium manganese oxide may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxide may include LiNi 1 / 3 Co 1 / 3 Mn1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 Examples of lithium nickel cobalt aluminum oxides include LiNi, etc. 0.80 Co 0.15 Al 0.05 O2. Non-limiting examples of lithium phosphates with an olivine structure may include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium iron phosphate include LiFePO4 (also abbreviated as LFP). Examples of lithium manganese phosphate include LiMnPO4.

[0387] In this application, unless otherwise specified, "positive electrode electrolyte material" refers to a solid electrolyte that can be used in the positive electrode layer. Positive electrode electrolyte materials can enhance the ion conductivity of the positive electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of the capacity of the positive electrode active material with the external environment.

[0388] Without limitation, the mass percentage of the positive electrode active material in the positive electrode active layer is ≥70%, and can also be 70% to 95%, or 75% to 90%.

[0389] Non-limitingly, the mass percentage of the positive electrode electrolyte material in the positive electrode active layer can be 0.1% to 30%, and optionally 5% to 20%.

[0390] In some embodiments, the positive electrode active layer optionally includes a conductive agent (which may be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent may be a carbon conductive agent. Non-limitingly, the carbon conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the positive electrode conductive agent may include, but is not limited to, one or more of SP, KS-6, acetylene black, branched Ketjen black ECP, SFG-6, vapor-grown carbon fiber VGCF, carbon nanotubes (CNTs), and graphene. Non-limitingly, the mass percentage of the positive electrode conductive agent in the positive electrode active layer may be 0–10%, more further 0–8%, even further 0.1–5%, and even further 0.5%–3%. When a positive electrode component including a positive electrode active material is prepared into a positive electrode active layer using a dry method, a positive electrode conductive agent can be added to the positive electrode component to improve the conductivity of the positive electrode active layer.

[0391] In some embodiments, the positive electrode active layer optionally includes a binder (which may be referred to as a positive electrode binder). As a non-limiting example, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a terpolymer of PVDF-tetrafluoroethylene-propylene, a terpolymer of PVDF-hexafluoropropylene-tetrafluoroethylene, a tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. Typically, the mass percentage of the positive electrode binder in the positive electrode active layer can be 0–10%, more commonly 0–8%, further commonly 0.1%–5%, further commonly 0.5%–5%, and further commonly 0.5%–3%. By preparing the positive electrode active layer after wet-processing the positive electrode composition including the positive electrode active material into a positive electrode slurry, the positive electrode binder can be placed in the positive electrode slurry, which can assist in film formation and also facilitate the formation of a good electrical contact network between the positive electrode active materials in the positive electrode layer in solid-state batteries.

[0392] As a non-limiting example, the positive current collector has two surfaces that are opposite to each other in its own thickness direction, and the positive active layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0393] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. In the positive electrode current collector, the composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. In the positive electrode current collector, the composite current collector may be obtained by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the positive electrode current collector may include at least one of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limitingly, in the positive electrode current collector, the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0394] Positive electrode sheets can be prepared using dry or wet methods. For example, they can be dry-pressed into films. Alternatively, they can be wet-coated and dried to form films.

[0395] In some embodiments, the positive electrode sheet can be prepared by: dry mixing the components used to prepare the positive electrode sheet, such as the positive electrode active material, positive electrode electrolyte material, positive electrode conductive agent, positive electrode binder, and any other components; then heating and pressurizing the mixed material to knead it into a clump; hot rolling pressing to form a self-supporting positive electrode sheet; and hot rolling bonding the self-supporting positive electrode sheet with a positive electrode current collector, wherein the self-supporting positive electrode sheet can be bonded to at least one side (single or double sides) of the positive electrode current collector to obtain the positive electrode sheet. Non-limitingly, a dual planetary mixer can be used for dry mixing. Non-limitingly, a kneading and pressing process can be performed using a Banbury mixer. Non-limitingly, the temperature for hot rolling pressing can be 75°C to 85°C, and further, such as 78°C, 80°C, 82°C, etc. The method of assembling solid-state batteries using positive electrode sheets is suitable for industrial mass production.

[0396] In some embodiments, the positive electrode sheet can be prepared by dispersing the components used to prepare the positive electrode sheet, such as positive electrode active material, positive electrode electrolyte material, positive electrode conductive agent, positive electrode binder, and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated onto at least one surface of the positive electrode current collector, and after drying and other processes, the positive electrode sheet is obtained. Taking a sulfide solid electrolyte as an example, the organic solvent in the positive electrode slurry can include one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, etc., and more specifically, p-xylene. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40wt% to 80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPa·s to 25000 mPa·s. When coating the positive electrode slurry, the coating surface density on both sides of the positive electrode current collector, based on dry weight (excluding solvent), can be, but is not limited to, 15 mg / cm³. 2 ~35mg / cm 2 .

[0397] In solid-state batteries, the compaction density of the positive electrode layer can be, but is not limited to, 3.0 g / cm³. 3 ~3.6g / cm 3 3.3g / cm³ is an option. 3 ~3.5g / cm 3 .

[0398] In this application, unless otherwise stated, the compaction density of the cathode layer is equal to the ratio of the mass to the volume of the cathode layer.

[0399] The following is a description of the negative electrode layer.

[0400] The negative electrode layer can be formed based on a solid electrolyte membrane or provided by a pre-fabricated negative electrode sheet, and can be a negative electrode sheet that is applicable to solid-state batteries in the art. It is understood that the solid electrolyte membrane includes the composite electrolyte layer provided in this application, and can be a composite electrolyte membrane.

[0401] The negative electrode sheet can be prepared by dry or wet methods. For example, it can be formed into a film by dry pressing. Alternatively, it can be formed into a film by wet coating.

[0402] In this application, unless otherwise specified, the negative electrode layer includes at least a negative electrode active layer.

[0403] In this application, unless otherwise stated, the negative electrode sheet includes at least a negative electrode active layer.

[0404] Unless otherwise stated in this application, the negative electrode active layer includes at least a negative electrode active material.

[0405] Without limitation, the negative electrode active layer may include a negative electrode electrolyte material.

[0406] In this application, unless otherwise stated, "negative electrode electrolyte material particles" refers to solid electrolytes that can be used in the negative electrode layer.

[0407] Non-limiting, the mass percentage of the negative electrode active material in the negative electrode active layer can be ≥80%, and more preferably ≥90%. Non-limiting, the mass percentage of the negative electrode active material in the negative electrode active layer can be 80% to 99%, optionally 90% to 99%, and more preferably 95% to 99%, and can also be any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, etc.

[0408] Non-limitingly, the mass percentage of the negative electrode electrolyte material in the negative electrode active layer can be 0% to 30%, preferably 0.1% to 30%, and further preferably 5% to 20%.

[0409] In some implementations, the negative electrode active material is a lithium indium alloy (InLi alloy).

[0410] In some embodiments, the negative electrode layer or negative electrode sheet is an InLi alloy film.

[0411] In some embodiments, the negative electrode active material may also be a negative electrode active material known in the art for use in solid-state batteries. As a non-limiting example, the negative electrode active material may include one or more of the following materials: elemental silicon, elemental tin, silicon-carbon composites, silicon suboxide, graphite, and metallic lithium. However, this application is not limited to these materials or substances, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0412] In some embodiments, the negative electrode active material includes a silicon-based material, and more particularly, it can be a silicon-based material. Non-limitingly, the mass percentage of the silicon-based material in the negative electrode active layer can be 80% to 99%, optionally 90% to 99%, more preferably 95% to 99%, and can also be any of the following percentages or a range selected from any two of the following percentages: 80%, 82%, 84%, 85%, 86%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, etc.

[0413] In some embodiments, the silicon-based material includes a silicon-carbon composite material, and more specifically, a silicon-carbon composite material. A silicon-carbon composite material is a silicon-based material comprising a porous carbon matrix and elemental silicon located within the pores of the porous carbon matrix. Silicon-carbon composite materials can be obtained using a vapor deposition method. Those skilled in the art can prepare silicon-carbon composite materials using conventional methods in the art.

[0414] In some embodiments, the negative electrode sheet may include a negative current collector and a negative active layer disposed on at least one surface of the negative current collector, the negative active layer comprising a negative active material. As a non-limiting example, the negative current collector has two surfaces opposite to each other in its own thickness direction, and the negative active layer is disposed on either or both of the two opposite surfaces of the negative current collector.

[0415] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. In the negative electrode current collector, the composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the negative electrode current collector may include at least one of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limitingly, in the negative electrode current collector, the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0416] In some embodiments, the negative electrode active layer optionally includes a conductive agent (which may be referred to as a negative electrode conductive agent). Non-limitingly, the negative electrode conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. Non-limitingly, the mass percentage of the negative electrode conductive agent in the negative electrode active layer may be 0–15%, more preferably 0–10%, and even more preferably 0–5%.

[0417] In some embodiments, the negative electrode active layer optionally includes an adhesive (denoted as negative electrode adhesive). As a non-limiting example, the negative electrode adhesive may include one or more of styrene-butadiene rubber (SBR), polyacrylic acid (PAA) derivatives, sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS). Non-limitingly, the mass percentage of the negative electrode adhesive in the negative electrode active layer may be 0–10%, more further 1%–10% or 0–5%, even more further 1%–5%, and even more preferably 1%–3%.

[0418] In some embodiments, the negative electrode active layer may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)). The mass percentage of the other additives in the negative electrode active layer may be 0–15%, more preferably 0–10%, even more preferably 0–5%, even more preferably 0–3%, and even more preferably 0–2%.

[0419] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as negative electrode active material, negative electrode conductive agent, negative electrode binder, and any other components, in a solvent to form a negative electrode slurry. Taking a negative electrode component including a sulfide solid electrolyte as an example, a non-limiting example of a solvent is p-xylene. Further, the negative electrode slurry is coated onto at least one surface of a negative electrode current collector, and after drying or other processes, the negative electrode sheet is obtained. The surface of the negative electrode current collector coated with the negative electrode slurry can be a single surface of the negative electrode current collector or both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 30wt% to 70wt%, optionally 40wt% to 60wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000 mPa·s to 10000 mPa·s, optionally 3000 mPa·s to 10000 mPa·s. When coating the negative electrode slurry, the surface area density of the coating on one side of the negative electrode current collector, based on dry weight (excluding solvent), can be, but is not limited to, 1.5 mg / cm³. 2 ~22mg / cm 2 However, it is not limited to this.

[0420] In some implementations, the compaction density of the negative electrode layer in a solid-state battery can be, but is not limited to, 1.0 g / cm³. 3 ~2.0g / cm 3 1.0g / cm³ is an optional value. 3 ~1.8g / cm 3 .

[0421] In this application, unless otherwise stated, the compaction density of the negative electrode layer is equal to the ratio of the mass to the volume of the negative electrode layer.

[0422] The types of solid electrolytes present in different film layers of a solid-state battery can be the same or different. For example, the solid electrolytes in the positive electrode layer and the solid electrolyte layer can be the same or different.

[0423] Non-limitingly, a solid-state battery cell can be prepared by stacking a positive electrode, a composite electrolyte membrane, and a negative electrode in sequence, with the composite electrolyte membrane placed between the positive and negative electrodes.

[0424] Non-limitingly, a solid-state battery cell can be prepared by sequentially stacking a positive electrode, a composite electrolyte membrane, and a negative electrode, placing the composite electrolyte membrane between the positive and negative electrodes, and then densifying the membrane. Densification can be achieved through a warm isostatic pressing process.

[0425] In some embodiments, the solid-state battery may include an outer packaging. This outer packaging can be used to encapsulate the aforementioned solid-state battery cell.

[0426] In some embodiments, the outer packaging of a solid-state battery can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of a solid-state battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic; further, non-limiting examples of plastics may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0427] This application does not impose any particular limitation on the shape of the solid-state battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 1 This is an example of a square-structured solid-state battery cell 5.

[0428] In some of these implementations, reference is made to... Figure 2 The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. A solid-state battery cell 52 is encapsulated within the receiving cavity. The number of solid-state battery cells 52 contained in a single solid-state battery cell 5 may be one or more, which can be selected by those skilled in the art according to actual needs.

[0429] Solid-state batteries can be battery device 4 or battery pack 1.

[0430] The battery device includes at least one solid-state battery cell. The number of solid-state battery cells in the battery device can be one or more, and those skilled in the art can select an appropriate number according to the application and capacity of the battery device.

[0431] Figure 3 This is battery device 4, used as an example. (See reference...) Figure 3 In the battery device 4, multiple solid-state battery cells 5 can be arranged sequentially along the length of the battery device 4. Of course, they can also be arranged in any other manner. Furthermore, the multiple solid-state battery cells 5 can be fixed in place using fasteners.

[0432] Optionally, the battery device 4 may also include a housing with a receiving space in which a plurality of solid-state battery cells 5 are housed.

[0433] In some embodiments, the battery devices described above can also be assembled into a battery pack, and the number of battery devices contained in the battery pack can be one or more. Those skilled in the art can select an appropriate number according to the application and capacity of the battery pack.

[0434] Figure 4 and Figure 5 This is battery pack 1 as an example. (See reference...) Figure 4 and Figure 5 The battery pack 1 may include a battery box and multiple battery devices 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery devices 4. The multiple battery devices 4 can be arranged in any manner within the battery box.

[0435] In a second aspect of this application, a composite electrolyte membrane is provided, which includes a composite electrolyte layer, the definition of which can be found in the first aspect of this application.

[0436] In some embodiments, the composite electrolyte membrane is composed of a composite electrolyte layer.

[0437] In some embodiments, the composite electrolyte layer includes an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer includes a halide solid electrolyte, and the second electrolyte layer includes a sulfide solid electrolyte.

[0438] In some embodiments, the composite electrolyte layer has the same characteristics as those in the first aspect of this application.

[0439] In this composite electrolyte membrane, the use of an organic polymer porous network membrane improves the flexibility and mechanical strength while maintaining good ionic conductivity. The composite electrolyte membrane can provide a composite electrolyte layer with good ionic conductivity, good flexibility, high mechanical strength and stable positive and negative electrode interface contact for solid-state batteries, which is conducive to independent large-scale production.

[0440] In a third aspect of this application, a method for preparing a composite electrolyte membrane is provided, which can be used to prepare a solid-state battery according to the first aspect of this application.

[0441] In some embodiments, the composite electrolyte layer is prepared by a method including the following steps: placing a first electrolyte membrane and a second electrolyte membrane on both sides of an organic polymer porous mesh membrane, and then hot rolling them to prepare the composite electrolyte membrane.

[0442] In some embodiments, a method for preparing a composite electrolyte membrane is provided, comprising the following steps: placing a first electrolyte membrane and a second electrolyte membrane on both sides of an organic polymer porous mesh membrane, and performing hot rolling pressing to embed at least a portion of the second electrolyte membrane into the organic polymer porous mesh membrane, thereby preparing a composite electrolyte membrane.

[0443] In some embodiments, a method for preparing a composite electrolyte membrane is provided, comprising the following steps: placing a first electrolyte membrane and a second electrolyte membrane on opposite sides of an organic polymer porous mesh membrane, and hot-rolling them to embed at least a portion of the second electrolyte membrane into the organic polymer porous mesh membrane, thereby preparing a composite electrolyte membrane; wherein the organic polymer porous mesh membrane includes through-pores. Optionally, the first electrolyte membrane comprises a halide solid electrolyte, and the second electrolyte membrane comprises a sulfide solid electrolyte.

[0444] After hot rolling, the first electrolyte membrane and the second electrolyte membrane may each have a portion remaining on the two sides of the organic polymer porous mesh membrane, or they may be substantially completely embedded in the organic polymer porous mesh membrane. The total embedding degree of the first electrolyte membrane and the second electrolyte membrane can be characterized by the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer.

[0445] The overall ionic conductivity of the composite electrolyte membrane is closely related to the ionic conductivity of the first and second electrolyte layers, and is also affected by factors such as the porosity and tortuosity of the organic polymer porous network membrane.

[0446] In some embodiments, the organic polymer porous mesh membrane can be prepared by a method including step S10: the polymer mesh membrane can be obtained by further pore formation of a polymer film obtained by dry or wet process.

[0447] In some embodiments, the through-pores in the organic polymer porous mesh film can be formed by one or more of the following methods: mechanical drilling, laser drilling, chemical etching, mechanical stretching, and heavy ion drilling, etc.

[0448] In some embodiments, the method for preparing the composite electrolyte membrane satisfies one or more of the following characteristics:

[0449] (g1) The first electrolyte membrane is prepared by a method comprising the following steps: hot rolling a first mixture comprising a first solid electrolyte and a first fibrous polymer binder to obtain a first electrolyte membrane; optionally, the first solid electrolyte comprises a halide solid electrolyte.

[0450] (g2) The second electrolyte membrane is prepared by a method comprising the following steps: hot rolling is performed on a second mixture comprising a second solid electrolyte and a second fibrous polymer binder to obtain a second electrolyte membrane; optionally, the second solid electrolyte comprises a sulfide solid electrolyte.

[0451] In some embodiments, the first electrolyte membrane may be prepared using a method including step S100.

[0452] S100: The first electrolyte and the fiberizable polymer (denoted as the first fiberizable polymer) are mixed, and after pre-heating treatment, the mixture is subjected to fiberization treatment to obtain the first fiberized electrolyte material; the first fiberized electrolyte material is subjected to hot rolling to obtain the first electrolyte membrane.

[0453] In some embodiments, the second electrolyte membrane can be prepared using a method including step S200.

[0454] S200: The second electrolyte and the fiberizable polymer (denoted as the second fiberizable polymer) are mixed, preheated, and then fiberized to obtain the second fiberized electrolyte material; the second fiberized electrolyte material is hot-rolled to obtain the second electrolyte membrane.

[0455] In steps S100 and S200, the definitions of the first electrolyte and the second electrolyte can be found in the first aspect of this application. The type and size parameters of the first and second electrolytes in the composite electrolyte membrane and solid-state battery can be controlled by selecting suitable raw materials. For example, the volumetric cumulative distribution curve of the electrolyte raw material particle size can be obtained using a laser particle size analyzer to confirm the D-value of the electrolyte raw material. v 99 and average particle size. It can also control the electrolyte raw material's ability to pass through a sieve of a specific mesh size to control the maximum particle size, and can also adjust D. v 99 and average particle size.

[0456] The following methods can be used to test D. v99. A Malvern 2000 (MasterSizer 2000) laser particle size analyzer was used, following the standard procedure GB / T19077-2016 / ISO 13320:2009. The detailed test procedure included: taking an appropriate amount of the sample to be tested, adding 20 mL of solvent (the sample concentration should be 8%–12% opacity), sonicating for 5 min (53 kHz / 120 W) to ensure thorough dispersion, and then measuring the sample according to GB / T19077-2016 / ISO 13320:2009. Non-limiting examples of solvents include p-xylene. After the sample was poured into the injection tower, it circulated with the solution to the test optical path system. Under the irradiation of the laser beam, the particle size distribution characteristics could be obtained by receiving and measuring the energy distribution of the scattered light. Based on the test data, a particle size distribution map was plotted, and the Dsize was obtained from the distribution map. v Parameters such as 99 were used. To avoid agglomeration during the drying process affecting particle size testing, a dispersion test was performed on a washed and moistened sample.

[0457] D of sulfide solid electrolytes was tested using a laser particle size analyzer. v When parameters such as 99 are used, dispersants such as ammonium polycarboxylate are also added.

[0458] In step S100, the first fibrous polymer is a precursor of the first fibrous polymer binder, which can be converted into the first fibrous polymer binder after fibrosis treatment.

[0459] In step S200, the second fiberizable polymer is a precursor to the second fiberizable polymer binder, which can be converted into the second fiberizable polymer binder after fiberization treatment.

[0460] In steps S100 and S200, the pre-heating treatment serves to promote the full fiberization of the polymer binder. Non-limitingly, the temperature for the pre-heating treatment can be 60°C to 120°C, and the pre-heating time can be 5 min to 60 min, but is not limited thereto.

[0461] In step S100, the parameters for the fiberization treatment include the holding temperature and the holding time. Through the fiberization treatment, the first fiberizable polymer, which is uniformly mixed with the first electrolyte, is transformed into a first fiberizable polymer binder, which can improve the mixing uniformity between the first electrolyte and the first fiberizable polymer binder in the first mixture.

[0462] In step S200, the parameters for the fiberization treatment include the holding temperature and the holding time. Through the fiberization treatment, the second fiberizable polymer, which is uniformly mixed with the second electrolyte, is transformed into a second fiberizable polymer binder, which can improve the mixing uniformity between the second electrolyte and the second fiberizable polymer binder in the second mixture.

[0463] In this application, the hot rolling step involved in preparing the composite electrolyte membrane can be performed once or multiple times unless otherwise specified. Unless otherwise specified, the temperature for hot rolling can be 60°C to 120°C, and the holding time can be 5 min to 60 min, but is not limited thereto.

[0464] It is understandable that the proportion of materials used in the preparation of composite electrolyte membranes can be adjusted according to the target composition of the composite electrolyte membrane.

[0465] In some embodiments, the prepared composite electrolyte membrane is the composite electrolyte membrane described in the second aspect of this application.

[0466] Composite electrolyte membranes can be prepared using simple methods suitable for large-scale production.

[0467] In a fourth aspect of this application, an electrical device includes at least one of the solid-state battery described in the first aspect of this application, the composite electrolyte membrane described in the second aspect of this application, and the composite electrolyte membrane prepared by the method described in the third aspect of this application.

[0468] Electrical devices including the aforementioned solid-state batteries and / or the aforementioned composite electrolyte membranes may have corresponding advantages, which will not be elaborated here.

[0469] In some embodiments, the electrical device includes at least one of the solid-state batteries of any of the embodiments provided in this application.

[0470] In a non-limiting sense, solid-state batteries can be used as a power source for electrical devices or as an energy storage unit for electrical devices. Electrical devices can include, but are not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Mobile devices can be, for example, mobile phones, laptops, etc.; electric vehicles can be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric motorcycles, power tools, etc., but are not limited to these. This electrical device can also be applied to military equipment, aerospace, and other fields, and can also be applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power plants.

[0471] As an electrical device, solid-state batteries can be selected based on its usage requirements.

[0472] Figure 6 Here is an example of an electrical device 6. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of this electrical device for solid-state batteries, a battery device or battery pack can be used.

[0473] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a thin and light design and can use solid-state batteries as their power source.

[0474] The following describes some embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where the technology or conditions are not specified in the embodiments, they are performed according to the description above, or according to the technology or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially, or can be synthesized from commercially available products using conventional methods.

[0475] In the following examples, room temperature refers to 20°C to 30°C.

[0476] In the following examples, unless otherwise specified, the use of organic solvents to disperse sulfide solid electrolyte materials is involved. The organic solvent may be one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, etc., and may further be p-xylene.

[0477] In the following examples, unless otherwise specified, the parameters involved can be confirmed and / or adjusted by referring to the test methods described above. For example, the thermal decomposition temperature of polymer fibers in porous organic polymer membranes can be determined using thermogravimetric analysis (TGA) with a thermogravimetric analyzer (Mettler-Toledo TGA-2); the parameters involving electrolyte raw material D... v The particle size parameter of 99 can be tested using a Malvern 2000 (MasterSizer2000) laser particle size analyzer, and larger particles can also be removed by sieving.

[0478] It should be noted that the following embodiments and examples use all-solid-state batteries as non-limiting examples of solid-state batteries.

[0479] In the following embodiments and comparative examples, unless otherwise stated, the steps involving sulfide solid electrolytes and materials or films containing them are carried out in an argon atmosphere.

[0480] In the following embodiments, porous nylon mesh is used as a non-limiting example of an organic polymer porous mesh membrane, and the thermal decomposition temperature of the nylon fiber used is about 250°C; polytetrafluoroethylene (PTFE) is used as a non-limiting example of a fiberizable polymer, and accordingly, the first fiberizable polymer binder in the first electrolyte membrane and the first electrolyte layer is PTFE, and the second fiberizable polymer binder in the second electrolyte membrane and the second electrolyte layer is also PTFE.

[0481] In the following examples, the ionic conductivity of both the halide solid electrolyte material and the sulfide solid electrolyte material used at 25°C is greater than 1 mS / cm, and is in the range of 1 mS / cm to 10 mS / cm.

[0482] I. Preparation of solid-state batteries, taking the preparation of all-solid-state lithium-ion secondary batteries as an example.

[0483] Example 1.

[0484] (I) Preparation of porous membranes (porous nylon mesh) made of organic polymers

[0485] Polyporous nylon mesh is made by laser-drilling perforated holes in a chemical fiber woven mesh made from nylon filaments through wire mesh processing.

[0486] In this example, the prepared porous nylon mesh has a thickness of 120 micrometers (μm), a tensile strength of 23 MPa, a tortuosity of 1 (the through holes are mostly straight), and a porosity of 75%. The average diameter of the through holes is 100 μm (within the range of 60 μm to 200 μm), and the diameter of the through holes at different thickness positions is basically equal to 100 μm.

[0487] (II) Preparation of composite electrolyte membrane

[0488] (1) Raw material measurement

[0489] Based on the target mass percentage of the composite electrolyte membrane, it provides 70% halide solid electrolyte material, 20% sulfide solid electrolyte material, 1.8% fiberizable polymer and 8.2% prepared organic polymer porous mesh membrane (porous nylon mesh).

[0490] The sulfide solid electrolyte is Li 5.5 PS 4.5 Cl 1.5 (Maximum particle size 5 μm) The fibrous polymer is PTFE, and the organic polymer porous mesh membrane uses a prepared porous nylon mesh. The halide solid electrolyte is LiInCl (maximum particle size 5 μm), see Table 1.

[0491] (2) Preparation of the first fibrous electrolyte material (including halide solid electrolyte)

[0492] According to mass percentage, 98 wt% of halide solid electrolyte material and 2 wt% of fiberizable polymer are mixed to obtain a uniform powder (first premix); the obtained powder is pre-heated (pre-heating temperature is 80℃, pre-heating time is 10 min); the pre-heated powder is then fiberized (parameters are manual grinding for 15 min) to obtain the fiberized solid electrolyte material, denoted as the first fiberized electrolyte material; the first fiberized electrolyte material is subjected to single or multiple (using 2 times) hot rolling to obtain halide solid electrolyte membrane A, i.e., the first electrolyte membrane, also denoted as halide electrolyte membrane. Hot rolling conditions: temperature is 80℃, pressure is 2 MPa.

[0493] (3) Preparation of second fibrous electrolyte materials (including sulfide solid electrolytes)

[0494] According to mass percentage, 98 wt% of sulfide solid electrolyte material and 2 wt% of fiberizable polymer are mixed to obtain a uniform powder (second premix); the obtained powder is pre-heated (pre-heating temperature is 80℃, pre-heating time is 10 min); the pre-heated powder is then fiberized (parameters are manual grinding for 15 min) to obtain the fiberized solid electrolyte material, denoted as the second fiberized electrolyte material; the second fiberized electrolyte material is then subjected to single or multiple (using 2 times) hot rolling to obtain sulfide solid electrolyte membrane B, i.e., the second electrolyte membrane, also denoted as sulfide electrolyte membrane. Hot rolling conditions: temperature is 80℃, pressure is 2 MPa.

[0495] (4) Perform compounding

[0496] Solid electrolyte membranes A and B are placed on opposite sides of a nylon mesh and subjected to single or multiple (up to 3 times) hot rolling to obtain an asymmetric composite solid electrolyte membrane C, which is the composite electrolyte membrane. The composite electrolyte membrane consists of a first electrolyte layer (also referred to as a halide electrolyte layer) and a second electrolyte layer (also referred to as a sulfide electrolyte layer). Hot rolling conditions: temperature 80℃, pressure 2MPa.

[0497] In this example, both the halide electrolyte layer (first electrolyte layer) and the sulfide electrolyte layer (second electrolyte layer) are embedded in the through holes of the nylon mesh. The halide electrolyte layer and the sulfide electrolyte layer account for approximately 74% and 26% of the thickness of the composite electrolyte membrane, respectively, and the thickness of the organic polymer porous mesh membrane accounts for approximately 80% of the thickness of the composite electrolyte membrane.

[0498] In subsequent steps, after assembling the composite electrolyte membrane into an all-solid-state lithium-ion secondary battery, the thickness ratios of the halide electrolyte layer (first electrolyte layer) and the sulfide electrolyte layer (second electrolyte layer) in the composite electrolyte membrane, as well as the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer, can be controlled to be approximately equal.

[0499] (III) Prepare solid-state batteries, and further prepare all-solid-state lithium-ion secondary batteries.

[0500] (1) Preparation of positive electrode sheet

[0501] The preparation steps include: homogenization, coating, drying, rolling, and cutting.

[0502] According to mass percentage, 75wt% of the positive electrode active material NCM 811 20 wt% of a sulfide solid electrolyte (Li6PS5Cl, which can be denoted as LPSCl), 2 wt% of a conductive agent VGCF (vapor-grown carbon fiber), and 3 wt% of a binder nitrile rubber (NBR) are dispersed in xylene solvent and mixed evenly (homogeneous) using a planetary mixer to obtain a positive electrode slurry with a solid content of 65 wt%. The total loading capacity on both sides is 5 mAh / cm². 2 The positive electrode slurry is coated on both sides of the positive electrode current collector aluminum foil (the loading on both sides is basically the same), dried, and cut to obtain the positive electrode sheet.

[0503] In this example, the positive electrode sheet is prepared using a wet process: a planetary mixer is used for wet mixing, the binder is applied first, and after the adhesive solution is prepared, the remaining materials are added and stirred evenly to obtain the positive electrode slurry; then, the positive electrode slurry is coated with the required loading using a transfer coating method and dried to obtain the positive electrode roll; the positive electrode roll is cut into 30mm×30mm sizes to obtain the positive electrode sheet.

[0504] (2) Preparation of negative electrode sheet:

[0505] The preparation steps include: homogenization, coating, drying, rolling, and cutting.

[0506] According to mass percentage, 98 wt% of the negative electrode active material (silicon-carbon composite material, silicon-carbon elemental mass ratio 1:1) and 2 wt% of the binder polyvinylidene fluoride (PVDF) were dispersed in the solvent polymethylpyrrolidone (NMP) and mixed evenly (homogeneously) using a planetary mixer to obtain a negative electrode slurry with a solid content of 50 wt%. The total loading capacity on both sides was 6 mAh / cm². 2 The negative electrode slurry is coated on both sides of the copper foil of the negative electrode current collector (the loading on both sides is basically the same), dried, and cut to obtain the negative electrode.

[0507] In this example, the negative electrode sheet is prepared using a wet process: a planetary mixer is used for wet mixing, the binder is applied first, and after the adhesive solution is prepared, the remaining materials are added and stirred evenly to obtain a negative electrode slurry; the negative electrode slurry is coated with a transfer coating according to the required loading and dried to obtain a negative electrode roll; the negative electrode roll is cut into 32mm×32mm sizes to obtain a negative electrode sheet.

[0508] (3) Assemble and obtain an all-solid-state battery:

[0509] The positive electrode, composite electrolyte membrane, and negative electrode are stacked sequentially, tabs are welded together, and the battery is encapsulated in an aluminum-plastic film shell. Temperature isostatic pressing (to achieve densification) is then applied to obtain a soft-pack all-solid-state lithium-ion secondary battery. In the composite electrolyte membrane, a halide electrolyte layer (first electrolyte layer) is disposed on the positive electrode side, and a sulfide electrolyte layer (second electrolyte layer) is disposed on the negative electrode side.

[0510] Example 2. A composite electrolyte membrane and an all-solid-state lithium-ion secondary battery were prepared using the same method as in Example 1. The difference was that in the step of preparing the composite electrolyte membrane, the mass ratio of the sulfide solid electrolyte material and the halide solid electrolyte material in step (1) was adjusted to change the thickness percentage of the first electrolyte layer and the second electrolyte layer in the composite electrolyte membrane. The remaining operation steps were the same as in Example 1.

[0511] In Example 2, the composite electrolyte membrane obtained in step (4) has a thickness percentage of 25% for the first electrolyte layer and 75% for the second electrolyte layer. See Table 1 for details.

[0512] Example 3 uses the same method as Example 1 to prepare a composite electrolyte membrane and an all-solid-state lithium-ion secondary battery. The difference is that in the step of preparing the composite electrolyte membrane, different halide solid electrolyte materials are used, and the raw material mass ratio of sulfide solid electrolyte material and halide solid electrolyte material in step (1) and the mass percentage of fibrous polymer PTFE in steps (2) and (3) are adjusted. The remaining operation steps are the same as in Example 1.

[0513] In Example 3, the halide solid electrolyte material is Li3YCl6 (maximum particle size 6μm); the mass percentage of the fibrous polymer PTFE in steps (2) and (3) is adjusted to 1%; in the composite electrolyte membrane obtained in step (4), the thickness percentages of the halide electrolyte layer (first electrolyte layer) and the sulfide electrolyte layer (second electrolyte layer) in the composite electrolyte membrane are adjusted to 50% and 50% respectively. See Table 1.

[0514] Example 4. A composite electrolyte membrane and an all-solid-state lithium-ion secondary battery were prepared using the same method as in Example 1. The difference was that in the step of preparing the composite electrolyte membrane, different halide solid electrolyte materials were used, and the raw material mass ratio of sulfide solid electrolyte material and halide solid electrolyte material in step (1) was adjusted. The remaining operation steps were the same as in Example 1.

[0515] In Example 4, the halide solid electrolyte material is the same as in Example 3, namely Li3YCl6 (maximum particle size 6μm); in the composite electrolyte membrane obtained in step (4), the thickness percentages of the halide electrolyte layer (first electrolyte layer) and the sulfide electrolyte layer (second electrolyte layer) in the composite electrolyte membrane are changed accordingly, to 26% and 74%, respectively. See Table 1.

[0516] Example 5. A composite electrolyte membrane and an all-solid-state lithium-ion secondary battery were prepared using a method that was basically the same as in Example 1. The difference was that a different halide solid electrolyte material was used in the step of preparing the composite electrolyte membrane. The other steps were the same as in Example 1.

[0517] In Example 5, the halide solid electrolyte material is the same as in Example 3, namely Li3YCl6 (maximum particle size 6 μm). See Table 1 for details.

[0518] Example 6. A composite electrolyte membrane and an all-solid-state lithium-ion secondary battery were prepared using the same method as in Example 1. The difference was that porous nylon meshes of different thicknesses were prepared using the method in Example 1. Correspondingly, in the step of preparing the composite electrolyte membrane, the total amount of raw materials was changed while the mass ratio remained unchanged. Composite electrolyte membranes of different thicknesses were prepared in step (4). The remaining operation steps were the same as in Example 1.

[0519] In Example 6, the porous nylon mesh has a thickness of 80 μm, a tensile strength of 18 MPa, a tortuosity of 1 (all through holes are straight holes), and a porosity of 74%.

[0520] Examples 7-8. Composite electrolyte membranes and all-solid-state lithium-ion secondary batteries were prepared using a method similar to that in Example 1, except that the tortuosity of the porous nylon mesh was changed, while the other operation steps were the same as in Example 1.

[0521] In Example 7, the porous nylon mesh has a thickness of 120 μm, a tensile strength of 24 MPa, a tortuosity of approximately 3, and a porosity of 70%. The interconnecting paths of the pores are approximately zigzag-shaped.

[0522] In Example 8, the porous nylon mesh has a thickness of 120 μm, a tensile strength of 26 MPa, a tortuosity of approximately 7, and a porosity of 55%. The interconnecting paths of the pores are approximately zigzag-shaped.

[0523] Example 9. A composite electrolyte membrane was prepared using the same method as in Example 1, and an all-solid-state lithium-ion secondary battery was prepared using essentially the same method as in Example 1, except that the positive electrode active material was changed to NCM. 622 (LiNi 0.6 Co 0.2 Mn 0.2 O2).

[0524] Comparative Example 1. The first electrolyte layer is omitted (the composite electrolyte membrane does not contain a halide solid electrolyte).

[0525] A solid-state lithium-ion secondary battery was prepared using a method essentially the same as in Example 1, with the following differences: In the step of preparing the composite electrolyte membrane, when performing the composite process in step (4), the first electrolyte membrane (halide solid electrolyte membrane A) was omitted, and only the second electrolyte membrane (sulfide solid electrolyte membrane B) was used to composite with the porous nylon mesh. At the same time, the mass percentage of the fibrous polymer in step (3) was changed so that the mass percentage of the fibrous polymer binder in the composite electrolyte membrane was the same as in Example 1; in the step of preparing the solid-state battery, the second electrolyte membrane was placed on the negative electrode side. The remaining operation steps were the same as in Example 1.

[0526] In this example, the composite electrolyte membrane is composed of 90% sulfide solid electrolyte material, 1.8% fiberizable polymer, and 8.2% prepared organic polymer porous mesh membrane (porous nylon mesh) by mass percentage.

[0527] Comparative Example 2. The second electrolyte layer is omitted (the composite electrolyte membrane does not contain a sulfide solid electrolyte).

[0528] A solid-state lithium-ion secondary battery was prepared using a method essentially the same as in Example 5, with the following differences: In the step of preparing the composite electrolyte membrane, during step (4) of the composite process, the second electrolyte membrane (sulfide solid electrolyte membrane B) was omitted, and only the first electrolyte membrane (halide solid electrolyte membrane A) was used to composite with the porous nylon mesh. Simultaneously, the mass percentage of the fibrous polymer in step (2) was changed so that the mass percentage of the fibrous polymer binder in the composite electrolyte membrane was the same as in Example 1. In the step of preparing the solid-state battery, the first electrolyte membrane was placed on the positive electrode side. The remaining operating steps were the same as in Example 1.

[0529] In this example, the composite electrolyte membrane is composed of 90% halide solid electrolyte material, 1.8% fiberizable polymer, and 8.2% prepared organic polymer porous mesh membrane (porous nylon mesh) by mass percentage.

[0530] Comparative Example 3. Organic polymer porous mesh membrane omitted.

[0531] The all-solid-state lithium-ion secondary battery was prepared using a method that was basically the same as that in Example 1, except that the solid electrolyte layer was composed of a halide solid electrolyte membrane A (first electrolyte membrane) and a sulfide solid electrolyte membrane B (second electrolyte membrane) as in Example 1, with the halide electrolyte membrane located on the positive electrode side.

[0532] The positive electrode, the first electrolyte membrane (halide electrolyte membrane), the second electrolyte membrane (sulfide solid electrolyte membrane B), and the negative electrode are stacked in sequence, and tabs are welded on. The battery is then encapsulated in an aluminum-plastic film shell and subjected to isostatic pressing to obtain a soft-pack all-solid-state lithium-ion secondary battery.

[0533] III. Test Analysis Methods

[0534] (I) Composite electrolyte membrane and porous nylon mesh

[0535] 1. Thickness (D0) of the organic polymer porous network membrane and thickness (D3) of the composite electrolyte membrane.

[0536] The thicknesses of the prepared organic polymer porous mesh membrane and composite electrolyte membrane were confirmed by micrometer testing.

[0537] 2. Tensile strength

[0538] Test samples: composite electrolyte membranes or porous organic polymer membranes

[0539] The tensile testing machine used was an Instron 3365 tensile testing machine.

[0540] Test sample dimensions: A long strip sample with a width (W) of 20 mm and a length (L) greater than or equal to 60 mm. The measured value of the sample thickness is recorded as D. The cross-sectional area of ​​the sample is A = W × D. The initial distance between the fixtures is set to 40 ± 5 mm.

[0541] Test Procedure: Place both ends of the sample into the upper and lower ends of the clamp sequentially, and tighten the clamp. During the process, ensure that the sample and the clamp are in the same vertical direction, and that the force is uniform with no obvious tensile deformation. After preparation, perform a tensile test at a rate of 10 mm / min until the sample breaks. Record the maximum tensile force F that the sample withstands when it breaks. The tensile strength (T) of the sample is then calculated using the following formula: T = F / A.

[0542] 3. Confirmation of through-holes, dimensions (average diameter, diameter range at different thicknesses, etc.) and quantity statistics; tortuosity, porosity and other parameters of the organic polymer porous mesh membrane; dimensions, composition and distribution parameters of the first and second electrolyte layers, etc.

[0543] Samples to be tested: porous nylon mesh and composite electrolyte membrane

[0544] Using the FEI Scios 2HiVac device.

[0545] Using the dynamic resolution and layer-by-layer cutting technique of FIB-SEM, the three-dimensional structure of the sample was reconstructed. EDS elemental energy dispersive spectroscopy was then used to obtain the elemental distribution, confirming the contour boundaries of the through-holes at different thicknesses. Software quantitative analysis was used to obtain the pore distribution, volume distribution, and mass distribution of each component. Combined with parameters such as the total mass, total volume, and total thickness of the sample, one or more of the following parameters were obtained: the embedding status, position, particle composition and distribution, component composition and distribution, and size of the first and second electrolyte layers in the organic polymer porous mesh membrane; the average diameter of the through-holes; the diameter range of the through-holes at different thicknesses in the organic polymer porous mesh membrane; and the percentage of the thickness of the first electrolyte layer relative to the thickness of the composite electrolyte layer (F...). H1 The percentage of the thickness of the second electrolyte layer relative to the thickness of the composite electrolyte layer (F) H2 The percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer (F) H0 Parameters such as the tortuosity (τ) of porous organic polymer membranes.

[0546] For example, the tortuosity (τ) of the organic polymer porous mesh membrane was obtained by the following method: The three-dimensional structure of the sample was reconstructed using the nanoscale spatial dynamic resolution and layer-by-layer cutting technique of FIB-SEM, and the elemental distribution was obtained by EDS elemental energy dispersive spectroscopy to confirm the contour boundaries of the through-holes at different thicknesses; several through-holes were selected, the tortuosity of each through-hole was calculated, and then the average value was taken; at least 6 through-holes were sampled. The tortuosity of the selected through-holes was obtained by the following method: the center of each through-hole was determined at 10 μm intervals along the longitudinal direction, and the length L of the line connecting the centers of the holes at different thicknesses was measured. A According to the formula τ = L A The tortuosity is calculated using / L0, where L0 is the thickness of the organic polymer porous mesh membrane.

[0547] 4. Ionic conductivity testing of composite electrolyte membrane and composite electrolyte layer

[0548] The membrane to be tested: a composite electrolyte membrane or a membrane corresponding to a composite electrolyte layer extracted from a solid-state battery.

[0549] Test temperature: 25℃.

[0550] Test method: A 10mm diameter cylindrical stainless steel current collector is used to clamp the diaphragm under test in a mold at 350MPa. The current collector is then connected to an electrochemical workstation with a bias voltage of 10mV and a frequency range of 10... 6Electrochemical impedance spectroscopy (EIS) was performed on the membrane under test in the range of Hz to 10 Hz. The intersection point of the electrochemical impedance spectrum curve from the high frequency band to the low frequency band with the Z' axis was recorded as the resistance value R. The ionic conductivity of the membrane under test can be calculated using formula (1):

[0551]

[0552] Where d is the thickness of the diaphragm to be tested, and A is the contact area between the diaphragm to be tested and the current collector.

[0553] (II) Battery Performance Testing

[0554] 1. Discharge capacity, initial coulombic efficiency, and battery cycle performance testing

[0555] The operating voltage range of the battery under test was set to 2.6V to 4.3V. A constant current charge-discharge cycle test was performed to obtain the first-cycle discharge specific capacity, the first-cycle coulombic efficiency, and the number of cycles required to reduce capacity to 80% SOC. The test current was 0.1C (current density 0.5mA / cm²). 2) The test temperature was 60℃.

[0556] At 60℃, the battery under test is charged to 4.3V at a constant current of 0.1C, left to rest for 10 minutes, and then discharged to 2.6V at a constant current of 0.1C, left to rest for 5 minutes. This constitutes one charge-discharge cycle. The discharge capacity at this point is recorded as C0. This charge-discharge cycle is repeated for the same battery, and the discharge capacity Cn of the 1st cycle, 2nd cycle, ..., nth cycle is recorded until Cn / C0 ≤ 80%. The number of cycles is recorded as "the number of cycles from 60℃ capacity decay to 80% SOC".

[0557] The initial coulombic efficiency of the solid-state battery under test can be obtained by dividing the initial discharge capacity obtained from the test at 0.1C by the initial charge capacity.

[0558] The test results were recorded as "initial coulombic efficiency" and "number of cycles at 60°C with capacity decay to 80% SOC".

[0559] 2. Battery internal resistance (DCR)

[0560] DCR Test: At 25℃, charge the battery at a constant current of 1 / 3C to 4.3V, then charge it at a constant voltage of 4.3V until the current is 0.05C. After resting for 30 minutes, discharge it at a constant current of 1 / 3C for 90 minutes, and then rest for 120 minutes. Record the voltage V1. Then discharge it at 1C for 30 seconds and record the voltage V2. Then (V2-V1) / I C I C Given the current corresponding to a 1C rate, the internal resistance DCR of the battery is obtained.

[0561] IV. Test Analysis Results

[0562] In Examples 1-9, the porous nylon mesh organic polymer membranes all have through-pores. The resulting composite electrolyte membranes exhibit good ionic conductivity.

[0563] Examples 1-5 and 9 use the same organic polymer porous mesh membrane, wherein the through pores are straight pores and the tortuosity is 1.

[0564] The solid-state batteries prepared in Examples 1-9 all exhibit significantly longer cycle lives compared to Comparative Examples 1-3. Furthermore, they all demonstrate lower internal resistance and higher initial coulombic efficiency. For example, the relevant test results for Example 1 can be found in [reference needed]. Figure 7-9 .

[0565] Table 1.

[0566]

[0567] In Table 1, D0 represents the thickness of the organic polymer porous mesh membrane, and F... H0 F represents the percentage of the thickness of the organic polymer porous network membrane relative to the thickness of the composite electrolyte layer. H1 F is the percentage of the thickness of the first electrolyte layer (halide electrolyte layer) relative to the thickness of the composite electrolyte layer. H2 It is the percentage of the thickness of the first electrolyte layer (sulfide electrolyte layer) relative to the thickness of the composite electrolyte layer.

[0568] Table 2.

[0569]

[0570] The descriptions of the various implementation methods and embodiments above tend to emphasize the differences between them. Similarities or resemblances can be referenced interchangeably, and for the sake of brevity, they will not be repeated here. The technical features of the implementation methods and embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combinations of these technical features do not contradict each other, they should be considered within the scope of this specification.

[0571] It should be noted that this application is not limited to the above-described embodiments and examples. The above-described embodiments and examples are merely examples, and any embodiments and examples that have the same structure and achieve the same effect as the technical concept within the scope of this application are included in the technical scope of this application. The embodiments and examples described above only illustrate several embodiments and examples of this application, and although the descriptions are relatively detailed, they should not be construed as limiting the scope of the patent. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments or examples, and other ways of constructing embodiments or examples by combining some of the constituent elements of the embodiments or examples, are also included in the scope of this application without departing from the spirit of this application.

Claims

1. A solid-state battery, characterized by, It includes a positive electrode layer, a composite electrolyte layer and a negative electrode layer stacked in sequence; The composite electrolyte layer comprises an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer comprises a halide solid electrolyte, and the second electrolyte layer comprises a sulfide solid electrolyte. The first electrolyte layer is located between the positive electrode layer and the second electrolyte layer, and the second electrolyte layer is located between the first electrolyte layer and the negative electrode layer.

2. The solid-state battery of claim 1, wherein, The composite electrolyte layer satisfies one or more of the following characteristics: (a1) The through holes include straight through holes; optionally, at least 80% of the through holes are straight through holes; further optionally, the through holes are straight through holes; (a2) The composite electrolyte layer has an ionic conductivity greater than or equal to 1 mS / cm under at least one temperature condition between 25°C and 60°C; optionally, the composite electrolyte layer has an ionic conductivity greater than or equal to 1 mS / cm at 25°C. (a3) The side of the through hole near the positive electrode layer is filled with the halide solid electrolyte, and the side of the through hole near the negative electrode layer is filled with the sulfide solid electrolyte; (a4) The average diameter of the through holes is 1 μm to 200 μm, measured in terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film; (a5) The diameter of the through hole at different thickness positions of the organic polymer porous mesh film is 1 μm to 200 μm, measured in terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film. (b1) The organic polymer porous mesh membrane includes one or more of polyolefin fibers, polyamide fibers and polyester fibers; (b2) The organic polymer porous mesh membrane includes polymer fibers, and optionally, the thermal decomposition temperature of the polymer fibers is greater than or equal to 200°C. (b3) The mass percentage of the halide solid electrolyte in the first electrolyte layer is 80% to 100%; (b4) The sulfide solid electrolyte accounts for 80% to 100% of the mass of the second electrolyte layer; (c1) The tensile strength of the organic polymer porous mesh membrane or composite electrolyte layer is greater than or equal to 1 MPa; (c2) The tortuosity of the organic polymer porous mesh membrane is 1 to 10; (c3) The porosity of the organic polymer porous mesh membrane is 50% to 90%.

3. The solid-state battery of claim 2, wherein, The composite electrolyte layer satisfies one or more of the following characteristics: (a2') The average diameter of the through holes is 5 μm to 100 μm, measured in terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film; (a3') In terms of the dimension perpendicular to the thickness direction of the organic polymer porous mesh film, the diameter of the through hole at different thickness positions of the organic polymer porous mesh film ranges from 1 μm to 100 μm, and can be selected as 5 μm to 100 μm; (b1') The organic polymer porous mesh membrane includes one or more of nylon fibers, polypropylene fibers and polyester fibers; (b1”) The organic polymer porous mesh membrane includes a bio-based polymer fiber material. Optionally, the thermal decomposition temperature of the bio-based polymer fiber material is greater than or equal to 200°C, and can be 200°C to 800°C. (b2') The organic polymer porous mesh membrane includes polymer fibers, and the thermal decomposition temperature of the polymer fibers is 200°C to 800°C; (b3') The halide solid electrolyte accounts for 90% to 100% of the mass of the first electrolyte layer; (b4') The sulfide solid electrolyte accounts for 90% to 100% of the mass of the second electrolyte layer; (c1') The tensile strength of the organic polymer porous mesh membrane or composite electrolyte layer is greater than or equal to 10 MPa; (c2') The tortuosity of the organic polymer porous mesh membrane is 1 to 3; (c3') The porosity of the organic polymer porous mesh membrane is 50% to 80%.

4. The solid-state battery according to any one of claims 1 to 3, characterized by The composite electrolyte layer satisfies one or more of the following characteristics: (d1) The thickness of the first electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer; (d2) The thickness of the second electrolyte layer is 25% to 75% of the thickness of the composite electrolyte layer; (d3) The thickness of the organic polymer porous mesh membrane is 60% to 100% of the thickness of the composite electrolyte layer; (d4) The thickness of the organic polymer porous mesh membrane is greater than or equal to 10 μm; (d5) The organic polymer porous mesh membrane accounts for 5% to 30% of the mass of the composite electrolyte layer; (d6) The halide solid electrolyte accounts for 5% to 90% of the mass of the composite electrolyte layer; (d7) The sulfide solid electrolyte accounts for 5% to 90% of the mass of the composite electrolyte layer; (d8) The composite electrolyte layer includes a fibrous polymer binder, wherein the fibrous polymer binder accounts for 0.1% to 5% of the mass of the composite electrolyte layer.

5. The solid-state battery of claim 4, wherein, The composite electrolyte layer satisfies one or more of the following characteristics: (d1') The thickness of the first electrolyte layer is 45% to 55% of the thickness of the composite electrolyte layer; (d2') The thickness of the second electrolyte layer is 45% to 55% of the thickness of the composite electrolyte layer; (d3') The thickness of the organic polymer porous mesh membrane is 80% to 100% of the thickness of the composite electrolyte layer; (d4') The thickness of the organic polymer porous mesh membrane is 10 μm to 150 μm; (d5') ​​The organic polymer porous mesh membrane accounts for 5% to 20% of the mass of the composite electrolyte layer; (d6') The halide solid electrolyte accounts for 40% to 60% of the mass of the composite electrolyte layer; (d7') The sulfide solid electrolyte accounts for 40% to 60% of the mass of the composite electrolyte layer; (d8') The composite electrolyte layer includes a fibrous polymer binder, wherein the fibrous polymer binder accounts for 1% to 5% of the mass of the composite electrolyte layer; (d8”) At least one of the first electrolyte layer and the second electrolyte layer includes a fibrous polymer binder.

6. The solid-state battery according to any one of claims 1 to 5, characterized by The thickness of the organic polymer porous mesh membrane is 30 μm to 150 μm, and the percentage of the thickness of the organic polymer porous mesh membrane relative to the thickness of the composite electrolyte layer is 80% to 100%, optionally greater than or equal to 80% and less than 100%, and further optionally 80% to 95%.

7. The solid-state battery according to any one of claims 1 to 5, characterized in that, The thickness of the organic polymer porous mesh membrane is 10 μm to 30 μm.

8. The solid-state battery according to any one of claims 1 to 6, characterized in that, The composite electrolyte layer satisfies one or more of the following characteristics: (t1) The thickness of the organic polymer porous mesh membrane is greater than or equal to 80% and less than 100% of the thickness of the composite electrolyte layer, and is further optionally 80% to 95%; (t2) At least one of the first electrolyte layer and the second electrolyte layer includes a portion located outside the organic polymer porous mesh membrane; optionally, both the first electrolyte layer and the second electrolyte layer include a portion located outside the organic polymer porous mesh membrane.

9. The solid-state battery according to any one of claims 1 to 8, characterized in that, The composite electrolyte layer satisfies one or more of the following characteristics: (e1) the maximum particle diameter, D v 99 or an average particle diameter of 1 μm to 50 μm; (e2) the maximum particle diameter, D v 99 or an average particle diameter of 1 μm to 50 μm.

10. The solid-state battery according to claim 9, characterized in that, The composite electrolyte layer satisfies one or more of the following characteristics: (e1’) the maximum particle diameter, D v 99 or an average particle diameter of 1 to 10 μm; (e2’) the maximum particle diameter, D v 99 or an average particle diameter of 1 to 10 μm.

11. The solid-state battery according to any one of claims 1 to 10, characterized in that, The composite electrolyte layer has an ionic conductivity of 1 mS / cm to 10 mS / cm under at least one temperature condition between 25°C and 60°C. Optionally, the ionic conductivity of the composite electrolyte layer at 25°C is 1 mS / cm to 10 mS / cm.

12. The solid-state battery according to claim 11, characterized in that, The composite electrolyte layer has an ionic conductivity of 1 mS / cm to 5 mS / cm under at least one temperature condition between 25°C and 60°C. Optionally, the ionic conductivity of the composite electrolyte layer at 25°C is 1 mS / cm to 5 mS / cm.

13. The solid-state battery according to any one of claims 1 to 12, characterized in that, The composite electrolyte layer satisfies one or more of the following characteristics: (f1) The ionic conductivity of the halide solid electrolyte is 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C; optionally, the ionic conductivity of the halide solid electrolyte at 25°C is 1 mS / cm to 10 mS / cm. (f2) The halide solid electrolyte includes any one or more of LiInCl, Li3YBr6 or Li3YCl6; (f3) The sulfide solid electrolyte includes one or more of the following: silver sulfide-germanium sulfide type sulfide electrolyte, LGPS type sulfide electrolyte, and lithium sulfide-phosphorus pentasulfide complex type sulfide electrolyte; (f4) The ionic conductivity of the sulfide solid electrolyte is 1 mS / cm to 10 mS / cm at at least one temperature condition between 25°C and 60°C; optionally, the ionic conductivity of the sulfide solid electrolyte at 25°C is 1 mS / cm to 10 mS / cm. (f5) The first electrolyte layer includes a first fibrous polymer binder; the first fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin has a mass percentage of 0.1% to 5% in the first electrolyte layer, optionally 1% to 2%; optionally, the first fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer and polyvinylidene fluoride; (f6) The second electrolyte layer includes a second fibrous polymer binder; the second fibrous polymer binder includes a fluorinated polyolefin, wherein the fluorinated polyolefin has a mass percentage of 0.1% to 5% in the second electrolyte layer, optionally 1% to 2%; optionally, the second fibrous polymer binder includes one or more of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer and polyvinylidene fluoride.

14. The solid-state battery according to any one of claims 1 to 13, characterized in that, The positive electrode layer includes a positive electrode active layer, the positive electrode active layer includes a positive electrode active material, and the positive electrode active material includes a lithium transition metal oxide positive electrode material.

15. The solid-state battery according to claim 14, characterized in that, The positive electrode active material includes lithium nickel-based oxide positive electrode materials; wherein, the lithium nickel-based oxide positive electrode material contains Li element, non-lithium metal element and O element, and the non-lithium metal element includes Ni element; The lithium nickel-based oxide cathode material satisfies one or more of the following characteristics: (i) The atomic molar ratio of Ni to non-lithium metal elements in the lithium nickel-based oxide cathode material is q1, where 0.5 ≤ q1 ≤ 0.98; (ii) The lithium nickel-based oxide cathode material contains Ni and Li elements in an atomic molar ratio of q2:x2, wherein 0.5≤q2≤0.98 and 0.6≤x2≤1.2; (iii) The lithium nickel-based oxide cathode material comprises Ni and O elements in an atomic molar ratio of q3:x3, wherein 0.5≤q3≤0.98 and 1.6≤x3≤2.2; optionally, 1.6≤x3≤2.1; (iv) The lithium nickel-based oxide cathode material contains Co. (v) The lithium nickel-based oxide cathode material contains at least one of Mn and Al elements; optionally, the lithium nickel-based oxide cathode material contains Mn elements.

16. The solid-state battery according to claim 15, characterized in that, The positive electrode active material satisfies one or more of the following characteristics: (ti)0.8≤q1≤0.98; (tii)0.8≤q2≤0.98; (tiii) 0.8 ≤ x² ≤ 1.1; (tiv)0.8≤q3≤0.98; (tv)1.8≤x3≤2.06; (tvi) The positive electrode active material includes lithium nickel cobalt manganese-based oxide positive electrode material. Optionally, the mass percentage of the lithium nickel cobalt manganese-based oxide positive electrode material in the positive electrode active material is 80% to 100%, and optionally 90% to 100%. (tvii) The lithium nickel-based oxide cathode material accounts for 80% to 100% of the mass of the cathode active material, and can be selected as 90% to 100%.

17. The solid-state battery according to any one of claims 1 to 16, characterized in that, It meets one or more of the following characteristics: (h1) The solid-state battery is an all-solid-state battery; (h2) The solid-state battery is a lithium-ion secondary battery, which can be selected as an all-solid-state lithium-ion secondary battery.

18. A composite electrolyte membrane, characterized in that, The composite electrolyte layer includes an organic polymer porous mesh membrane, a first electrolyte layer at least partially embedded in the organic polymer porous mesh membrane, and a second electrolyte layer at least partially embedded in the organic polymer porous mesh membrane; the organic polymer porous mesh membrane includes through pores, the first electrolyte layer includes a halide solid electrolyte, and the second electrolyte layer includes a sulfide solid electrolyte.

19. The composite electrolyte membrane according to claim 18, characterized in that, The features of the composite electrolyte layer are the same as those in any one of claims 2 to 13.

20. A method for preparing a composite electrolyte membrane, characterized in that, The process includes the following steps: placing a first electrolyte membrane and a second electrolyte membrane on opposite sides of an organic polymer porous mesh membrane, and hot rolling them together to embed at least a portion of the second electrolyte membrane into the organic polymer porous mesh membrane, thereby preparing a composite electrolyte membrane; wherein the organic polymer porous mesh membrane includes through-pores, the first electrolyte membrane includes a halide solid electrolyte, and the second electrolyte membrane includes a sulfide solid electrolyte.

21. The method for preparing the composite electrolyte membrane according to claim 20, characterized in that, It meets one or more of the following characteristics: (g1) The first electrolyte membrane is prepared by a method comprising the following steps: mixing a first solid electrolyte and a first fibrous polymer binder, and hot rolling to obtain the first electrolyte membrane; wherein, the first solid electrolyte comprises a halide solid electrolyte; (g2) The second electrolyte membrane is prepared by a method including the following steps: mixing a second solid electrolyte and a second fibrous polymer binder, and hot rolling to obtain the second electrolyte membrane; wherein the second solid electrolyte includes a sulfide solid electrolyte.

22. The method for preparing the composite electrolyte membrane according to claim 20, characterized in that, The prepared composite electrolyte membrane is the composite electrolyte membrane described in claim 18 or 19.

23. An electrical appliance, characterized in that, It includes at least one of the solid-state battery according to any one of claims 1 to 17, the composite electrolyte membrane according to claim 18 or 19, and the composite electrolyte membrane prepared by the method of preparing the composite electrolyte membrane according to claim 20 or 21.

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