Solid-state electrolyte membrane, preparation method thereof and solid-state battery

Abstract

The invention relates to the technical field of solid-state batteries, in particular to a solid-state electrolyte membrane, a preparation method thereof and a solid-state battery. During application, the combination of the skeleton supporting layer, the through hole filling body and the elastic covering layer can give consideration to both high mechanical strength and high ionic conductivity. In the structural level, the framework supporting layer provides a framework supporting function, and the elastic covering layer can provide a buffering function for expansion of the positive electrode plate and the negative electrode plate. In the aspect of conductivity, on one hand, the combined solid electrolyte membrane has relatively high conductivity in the MD direction and the TD direction, and the rate capability of the solid battery is effectively improved; and on the other hand, the elastic covering layer arranged on the surface of the framework supporting layer of the prepared solid electrolyte membrane has an elastic buffering effect, and is beneficial to tight attachment with the surfaces of a positive plate and a negative plate, so that the solid-solid contact internal resistance is reduced, the wettability of contact between the solid electrolyte membrane and the plate is improved, and the performance of a solid battery is favorably exerted.

Description

Technical Field

[0001] The present application relates to the field of solid-state battery technology, and in particular to a solid-state electrolyte membrane and a preparation method thereof, and a solid-state battery. Background Art

[0002] Secondary batteries have been widely used in energy storage and electric vehicles. However, current mainstream liquid batteries are limited by the physical properties of organic electrolytes: liquid systems are incompatible with high-capacity metal anodes, resulting in limited energy density; the flammability of the electrolyte leads to the risk of thermal runaway, posing a safety hazard; and the conductivity decays rapidly at low temperatures. Currently, some batteries use solid-state electrolytes instead of liquid electrolytes, but these batteries suffer from poor wettability at the solid-solid interface and the difficulty in achieving both ionic conductivity and mechanical strength. Addressing these issues is a pressing technical challenge in this field. Summary of the Invention

[0003] In view of this, the present application provides a solid electrolyte membrane and a preparation method thereof, and a solid-state battery, which can optimize the wettability of solid-solid interface contact while taking into account ionic conductivity and mechanical strength.

[0004] In a first aspect, the present application provides a solid electrolyte membrane, comprising: a skeleton support layer, provided with a plurality of through holes extending through the thickness direction; a through hole filler, filled in each of the through holes one by one; and an elastic covering layer, covering at least one surface of the skeleton support layer, the elastic modulus of the elastic covering layer being smaller than the elastic modulus of the skeleton support layer; the material of the skeleton support layer is different from the materials of the through hole filler and the elastic covering layer, and the materials of the skeleton support layer, the through hole filler and the elastic covering layer all include conductive materials.

[0005] In combination with the first aspect, in a possible implementation, the shapes of the multiple through holes are selected from one or more of the following shapes: cylindrical through holes, polygonal through holes, frustum-shaped through holes, and through holes with curved vertical cross-sectional profiles; the porosity of the skeleton support layer is greater than 55%, the spacing between the geometric centers of adjacent through holes is greater than 50 nm, the diameter or side length of the through holes is any value between 10 nm and 500 nm, and the multiple through holes are evenly arranged on the skeleton support layer.

[0006] In combination with the first aspect, in a possible implementation, there are two elastic covering layers, and the two elastic covering layers respectively cover two sides of the skeleton supporting layer.

[0007] In combination with the first aspect, in a possible implementation, the thickness of the skeleton support layer is any value between 3 μm and 50 μm, and the thickness of the assembly of the skeleton support layer and the elastic covering layer is any value between 4 μm and 60 μm.

[0008] In combination with the first aspect, in one possible implementation, the material of the skeleton support layer includes one or more of the following materials: a solid electrolyte, a first binder, a second binder, and a dispersant; the crystallinity of the second binder is less than that of the first binder.

[0009] In combination with the first aspect, in a possible implementation, the materials used to make the through-hole filling body and the elastic covering layer include: a polymer-based electrolyte, an inorganic salt, and a plasticizer.

[0010] In a second aspect, the present application provides a solid-state battery comprising the aforementioned solid-state electrolyte membrane.

[0011] In a third aspect, the present application provides a preparation method for the aforementioned solid electrolyte membrane, the preparation method comprising: preparing a solid electrolyte, a binder and a dispersant into a first slurry; coating the first slurry on a carrier mold; drying and rolling the carrier mold coated with the first slurry, and removing the carrier mold to obtain a skeleton support layer; laser etching the skeleton support layer to prepare a plurality of through holes; preparing a polymer-based electrolyte, an inorganic salt and a plasticizer into a second slurry; spraying the second slurry into the through hole to form a through-hole filler; and spraying the second slurry onto the surface of the skeleton support layer to form an elastic covering layer; wherein the elastic modulus of the elastic covering layer is smaller than the elastic modulus of the skeleton support layer, the material of the skeleton support layer is different from the materials of the through-hole filler and the elastic covering layer, and the materials of the skeleton support layer, the through-hole filler and the elastic covering layer all include conductive materials.

[0012] In combination with the third aspect, in a possible implementation, the adhesive includes a first adhesive and a second adhesive, and the crystallinity of the second adhesive is lower than that of the first adhesive.

[0013] In combination with the third aspect, in a possible implementation method, coating the first slurry on the carrier mold includes: coating the first slurry on the metal carrier mold, and controlling the dry film thickness to be any value between 3μm and 50μm; spraying the second slurry onto the surface of the skeleton support layer to form an elastic covering layer includes: spraying the second slurry onto the surface of the skeleton support layer, and controlling the thickness of the elastic covering layer to be any value between 0.5μm and 5μm.

[0014] When used in this application, the combination of the skeleton support layer, through-hole filler, and elastic covering layer can achieve both high mechanical strength and high ionic conductivity. Structurally, the skeleton support layer provides skeletal support, while the elastic covering layer covering the surface of the skeleton support layer cushions the expansion of the positive and negative electrode sheets. Regarding electrical conductivity, the skeleton support layer, through-hole filler, and elastic covering layer provide ion conduction channels. The multiple through-holes filled with through-hole fillers that penetrate the skeleton support layer further enhance the ion conduction efficiency through the thickness of the skeleton support layer. The resulting solid electrolyte membrane exhibits high electrical conductivity in both the MD (machine direction) and TD (transverse direction), effectively improving the rate performance of the solid-state battery. Furthermore, since the positive and negative electrode sheets are located on one side of the solid electrolyte membrane, the low elastic modulus elastic covering layer facilitates close contact with the surfaces of the positive and negative electrode sheets, thereby reducing the solid-solid contact internal resistance and improving the wettability between the solid electrolyte membrane and the electrode sheets, thereby enhancing the electrical conductivity of the solid-state battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown is a schematic structural diagram of a skeleton support layer of a solid electrolyte membrane provided in one embodiment of the present application.

[0016] Figure 2 Shown is a partial structural cross-sectional view of a solid electrolyte membrane provided in one embodiment of the present application.

[0017] Figure 3 Shown is a schematic diagram of a solid-state battery provided in one embodiment of the present application.

[0018] Figure 4 Shown is a schematic diagram of the steps of a method for preparing a solid electrolyte membrane provided in one embodiment of the present application.

[0019] Figure 5 Shown is a schematic diagram of the steps of a specific embodiment of a method for preparing a solid electrolyte membrane.

[0020] Figure 6 Shown is a schematic diagram of the steps of another specific embodiment of a method for preparing a solid electrolyte membrane. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0022] Exemplary solid electrolyte membranes are as follows: Figure 1 The figure shows a schematic diagram of the structure of a skeleton support layer of a solid electrolyte membrane provided in one embodiment of the present application. The present application provides a solid electrolyte membrane, in one embodiment, such as Figure 1 As shown, the solid electrolyte membrane comprises: a skeleton support layer 1, a through-hole filling body 2, and an elastic covering layer 3. The skeleton support layer 1 is provided with a plurality of through-holes 101 extending through the thickness thereof. There are a plurality of through-hole filling bodies 2, each of which is filled in a one-to-one correspondence within each through-hole 101. The elastic covering layer 3 covers at least one surface of the skeleton support layer 1, and the elastic modulus of the elastic covering layer 3 is less than that of the skeleton support layer 1. The material of the skeleton support layer 1 is different from that of the through-hole filling body 2 and the elastic covering layer 3. The materials of the skeleton support layer 1, the through-hole filling body 2, and the elastic covering layer 3 all comprise electrically conductive materials.

[0023] When used in this embodiment, the combination of the skeleton support layer, the through-hole filler, and the elastic cover layer can achieve both high mechanical strength and high ionic conductivity. Structurally, the skeleton support layer 1 provides skeletal support, while the elastic cover layer 3 provides a buffer for the expansion of the positive and negative electrode sheets. Regarding electrical conductivity, the skeleton support layer 1, the through-hole filler 2, and the elastic cover layer 3 provide ion conduction channels, such as sodium and / or lithium ions. The multiple through-holes 101 formed through the skeleton support layer 1 and filled with the through-hole filler 2 further enhance the ion conduction efficiency along the thickness of the skeleton support layer 1. The resulting solid electrolyte membrane exhibits high electrical conductivity in both the MD and TD directions, effectively improving the rate capability of the solid-state battery. Furthermore, since the positive and negative electrode sheets are located on one side of the solid electrolyte membrane, the elastic cover layer 3, with its low elastic modulus, provides elasticity, facilitating close contact between the solid electrolyte layer and the surfaces of the positive and negative electrode sheets. This reduces the solid-solid contact internal resistance and improves the wettability between the solid electrolyte membrane and the electrode sheets, thereby enhancing the electrical conductivity of the solid-state battery.

[0024] Specifically, the elastic modulus of the elastic covering layer 3 is any value within a range of 20% to 80% of the elastic modulus of the skeleton supporting layer 1 , so as to provide sufficient elastic buffering effect.

[0025] In one embodiment, the shapes of the plurality of through-holes 101 are selected from one or more of the following: cylindrical through-holes, polygonal through-holes (through-holes with a rectangular, square, pentagonal, or other polygonal cross-section), frustum-shaped through-holes, and through-holes with a curved vertical cross-section (e.g., through-holes with an irregular profile). The vertical cross-section refers to a section parallel to the thickness of the skeleton support layer 1. The porosity of the skeleton support layer 1 is greater than 55% to further improve the ion conduction efficiency through the thickness of the skeleton support layer 1. The spacing between the geometric centers of adjacent through-holes 101 is greater than 50 nm to ensure that the skeleton support layer 1 provides support for the entire solid electrolyte membrane. The diameter or side length of the through-holes 101 ranges from 10 nm to 500 nm. The plurality of through-holes 101 are evenly distributed on the skeleton support layer 1 to uniformly distribute the ion conduction provided by the through-hole filler 2.

[0026] In one embodiment, the elastic covering layer 3 covers one side of the skeleton supporting layer 1 , that is, only one side of the skeleton supporting layer 1 is covered with the elastic covering layer 3 .

[0027] Figure 2 FIG. 1 is a cross-sectional view of a local structure of a solid electrolyte membrane provided by an embodiment of the present application. Figure 2 As shown, there are two elastic covering layers 3 , which respectively cover both sides of the skeleton support layer 1 , and can further improve the conductivity of the entire solid electrolyte membrane.

[0028] The thickness of the skeleton supporting layer 1 is any value between 3 μm and 50 μm, and the thickness of the assembly of the skeleton supporting layer 1 and the elastic covering layer 3 is any value between 4 μm and 60 μm.

[0029] Specifically, in one embodiment, the thickness of the skeleton support layer 1 is 3 μm, and an elastic covering layer 3 is provided on each of two opposite sides of the skeleton support layer 1. The thickness of each elastic covering layer 3 is 0.5 μm. The thickness of the solid electrolyte membrane formed by the combination of the skeleton support layer 1 and the two elastic covering layers 3 is 4 μm, which can improve the conductivity of the entire solid electrolyte membrane while having a certain lightweight performance.

[0030] Specifically, in one embodiment, the thickness of the skeleton support layer 1 is 6 μm, and an elastic covering layer 3 is provided on each opposite side of the skeleton support layer 1. The thickness of the single elastic covering layer 3 is controlled to 2 μm. The thickness of the solid electrolyte membrane after the skeleton support layer 1 and the two elastic covering layers 3 are combined is 10 μm, which can take into account both excellent electrical conductivity and overall structural rigidity.

[0031] Specifically, in one embodiment, the thickness of the skeleton support layer 1 is 50 μm, and an elastic covering layer 3 is provided on each opposite side of the skeleton support layer 1. The thickness of the single elastic covering layer 3 is controlled to 5 μm. The thickness of the solid electrolyte membrane after the skeleton support layer 1 and the two elastic covering layers 3 are combined is 60 μm, which can maximize the overall structural rigidity.

[0032] Specifically, in one embodiment, the material of the skeleton support layer 1 includes one or more of the following materials: a solid electrolyte, a first binder, a second binder, and a dispersant.

[0033] Specifically, if the solid-state battery is a lithium-ion battery, the solid-state electrolyte can be made of one or more of the following materials: Li-β-Al2O3 solid electrolyte, Lisicon solid electrolyte, sulfide lithium-ion solid electrolyte, PEO (polyethylene oxide)-based lithium salt, PMA (glycol methyl ether acetate)-based lithium salt, PEG (polyethylene glycol)-based lithium salt, and PAN (polyacrylonitrile)-based lithium salt. The first and second binders can be made of one or more of the following materials: PVDF (polyvinylidene fluoride), PMMA (polymethyl methacrylate), PTFE (polytetrafluoroethylene), and PAA (polyacrylic acid). The second binder has a lower crystallinity than the first binder.

[0034] Specifically, if the solid-state battery is a sodium-ion battery, the material of the solid-state electrolyte may include one or more of the following materials: Na-β-Al2O3 solid electrolyte, PEO (polyethylene oxide) based electrolyte, PAN (polyacrylonitrile) based electrolyte, PVDF (polyvinylidene fluoride) based electrolyte, Nasicon type solid electrolyte, perovskite (such as Na3xLa2 / 3−xTiO3) type electrolyte, Na3PS4 solid electrolyte, Na3OX solid electrolyte, polymer composite (such as PEO+NASICON composite) solid electrolyte.

[0035] In this embodiment, the solid electrolyte forms multiple ion transport channels. The second binder has a lower crystallinity than the first binder, thus forming a bicrystalline gradient. The high crystallinity of the first binder increases tensile strength and thus improves the rigidity of the skeleton, while the low crystallinity of the second binder can fill microcracks, thereby improving the toughness of the skeleton support layer 1.

[0036] Specifically, in one embodiment, the materials of the through-hole filling body 2 and the elastic covering layer 3 include: a polymer-based electrolyte, an inorganic salt, and a plasticizer.

[0037] If the solid-state battery is a lithium-ion battery, the polymer-based electrolyte may include one or more of the following materials: PVDF-based electrolyte, PEO-based electrolyte, PAN-based electrolyte, and PMMA-based electrolyte. The inorganic salt is a lithium salt, and the lithium salt includes one or more of the following materials: LiClO4, LiBF4, LiAsF6, LiPF6, LiBOB, LiDFOB, LiFSI, and LiTFSI. The plasticizer includes one or more of the following materials: dimethylformamide, diethyl carbonate, butyrolactone, ethylene carbonate, polycarbonate, and polyethylene glycol. The content of the plasticizer is greater than 20%.

[0038] If the solid-state battery is a sodium-ion battery, the polymer-based electrolyte may include one or more of the following materials: PVDF-based electrolytes, PEO-based electrolytes, and PAN-based electrolytes. The inorganic salt is a sodium salt, and the sodium salt includes one or more of the following materials: NaTFSI (sodium bis(trifluoromethanesulfonyl)imide), NaClO4 (sodium perchlorate), NaPF6 (sodium hexafluorophosphate), NaFSI (sodium bis(fluorosulfonyl)imide), NaClO4, and NaBF4. The plasticizer includes one or more of the following materials: PEG, organic carbonate, propylene carbonate, and succinonitrile. The plasticizer content is greater than 20%.

[0039] In this embodiment, the material system, through the coordinated design of a certain amount of plasticizer (>20%) with polymers and inorganic salts, provides a flexible ion-conducting channel and mechanical support for the polymer-based electrolyte. The plasticizer molecules can be inserted between polymer chains, increasing the spacing between them and enhancing the polymer's plasticity. Furthermore, it optimizes ionic conductivity and interfacial contact impedance, while simultaneously meeting the requirements of flexibility and high energy density.

[0040] Exemplary solid-state batteries are as follows: Figure 3 The present application also provides a solid-state battery. In one embodiment, referring to Figure 1 and Figure 3 As shown, including the aforementioned solid electrolyte membrane, the solid-state battery 10 uses a solid electrolyte membrane instead of a liquid electrolyte and a separator, which can greatly reduce the weight of inactive components inside the battery and improve the energy density and safety of the battery.

[0041] An exemplary method for preparing a solid electrolyte membrane is as follows: Figure 4 The figure shows a schematic diagram of the steps of a method for preparing a solid electrolyte membrane provided by an embodiment of the present application. The present application also provides a method for preparing the aforementioned solid electrolyte membrane. In one embodiment, as Figure 4 Shown, including: Step 110: prepare a first slurry by mixing a solid electrolyte, a binder and a dispersant.

[0042] In this step, the combination of a dual binder and a dispersant achieves uniform distribution of solid electrolyte particles, optimizing ion transport performance and ensuring sufficient stability in the first slurry. The combination of the first and second binders ensures that the resulting skeletal support layer possesses both rigidity (modulus 1.2 GPa) and toughness (elongation at break 25%).

[0043] Step 120: Coat the first slurry on the carrier mold.

[0044] In this step, a metal carrier mold with an easily strippable coating is used, and the coating thickness of the first slurry is controlled to a target value between 3 μm and 50 μm according to requirements.

[0045] Step 130 : Drying and rolling the carrier mold coated with the first slurry, and removing the carrier mold to obtain the skeleton support layer 1 .

[0046] In this step, drying and rolling can further flatten the first slurry to obtain a flat skeleton support layer 1. In addition, the drying and rolling process can make the skeleton support layer 1 more dense, which can reduce the assembly short-circuit rate of the solid-state battery made based on the solid electrolyte membrane of this application and improve the production yield of the solid-state battery. Among them, the dense skeleton support layer 1 can block the metal dendrites generated during the use cycle of the solid-state battery, thereby improving the safety of the battery.

[0047] In some embodiments, multiple rolling processes may be used, and the rolling pressure increases with the number of times. Low-pressure rolling is mainly used to flatten the skeleton support layer 1. As the rolling pressure increases, the first slurry can be gradually compacted to improve the rigidity of the skeleton support layer 1.

[0048] Step 140 : Laser-etch the skeleton support layer 1 to form a plurality of through holes 101 .

[0049] Step 150: Prepare a second slurry by mixing a polymer-based electrolyte, an inorganic salt, and a plasticizer.

[0050] Step 160 : spray the second slurry into the through hole 101 to form a through hole filling body 2 .

[0051] In this step, the plurality of through holes 101 filled with the through hole filling body 2 penetrating the skeleton support layer 1 can further improve the ion conduction efficiency in the thickness direction of the skeleton support layer 1 .

[0052] Step 170 : spraying the second slurry onto the surface of the skeleton support layer 1 to form an elastic covering layer 3 .

[0053] In this step, the elastic covering layer 3 can improve the ion conduction efficiency in the surface direction of the skeleton support layer 1 .

[0054] In this embodiment, the elastic modulus of the elastic covering layer 3 is lower than that of the skeleton support layer 1. The material of the skeleton support layer 1 is different from that of the through-hole filler 2 and the elastic covering layer 3. The materials of the skeleton support layer 1, through-hole filler 2, and elastic covering layer 3 all comprise electrically conductive materials. In practice, the combination of the skeleton support layer, through-hole filler, and elastic covering layer achieves both high mechanical strength and high ionic conductivity. Structurally, the skeleton support layer 1 provides skeletal support, while the elastic covering layer 3 cushions the expansion of the positive and negative electrode sheets. In terms of electrical conductivity performance: on the one hand, the skeleton support layer 1, the through-hole filler 2 and the elastic covering layer 3 provide ion conduction channels, such as providing sodium ion and / or lithium ion conduction. The multiple through-holes 101 filled with the through-hole filler 2 running through the skeleton support layer 1 can further improve the ion conduction efficiency in the thickness direction of the skeleton support layer 1. The combined solid electrolyte membrane has high conductivity in both MD and TD directions, effectively improving the rate performance of the solid-state battery; on the other hand, since the positive and negative electrodes are located on one side of the solid electrolyte membrane, the elastic covering layer 3 with a low elastic modulus is elastic, which is conducive to the close fit between the solid electrolyte layer and the surface of the positive and negative electrodes, thereby reducing the solid-solid contact internal resistance and improving the wettability of the contact between the solid electrolyte membrane and the electrode, which is conducive to improving the electrical conductivity of the solid-state battery.

[0055] In one embodiment, the embodiments in step 150 include the following embodiments corresponding to lithium-ion batteries and sodium-ion batteries: If the solid-state battery is a lithium-ion battery, the polymer-based electrolyte may include one or more of the following materials: PVDF-based electrolyte, PEO-based electrolyte, PAN-based electrolyte and PMMA-based electrolyte. The inorganic salt is a lithium salt, and the lithium salt includes one or more of the following materials: LiClO4, LiBF4, LiAsF6, LiPF6, LiBOB, LiDFOB, LiFSI and LiTFSI. The plasticizer includes one or more of the following materials: dimethylformamide, diethyl carbonate, butyrolactone, ethylene carbonate, polycarbonate and polyethylene glycol. The content of the plasticizer is greater than 20%. The second slurry is a mixture of the following three: a polymer-based electrolyte corresponding to the lithium-ion battery, a lithium salt, and a plasticizer corresponding to the lithium-ion battery; If the solid-state battery is a sodium-ion battery, the polymer-based electrolyte may include one or more of the following materials: PVDF-based electrolyte, PEO-based electrolyte, and PAN-based electrolyte. The inorganic salt is a sodium salt, and the sodium salt includes one or more of the following materials: NaTFSI (sodium bis(trifluoromethanesulfonyl)imide), NaClO4 (sodium perchlorate), NaPF6 (sodium hexafluorophosphate), NaFSI (sodium bis(fluorosulfonyl)imide), NaClO4, and NaBF4. The plasticizer includes one or more of the following materials: PEG, organic carbonate, propylene carbonate, and succinonitrile. The plasticizer content is greater than 20%. The second slurry is then a mixture of the following three: a polymer-based electrolyte corresponding to a sodium-ion battery, a sodium salt, and a plasticizer corresponding to a sodium-ion battery.

[0056] In some embodiments, a plurality of micron-scale groove structures arranged in parallel can be formed on the carrier mold. The size of a single groove structure is set to a depth of 2μm~6μm and a width of 15μm~30μm. The groove structure can provide a stress buffer space for rolling. The final skeleton support layer 1 has a striped raised structure. The elastic covering layer 3 is laid on the skeleton support layer 1 and fills the striped raised structure, so that the side of the elastic covering layer 3 away from the skeleton support layer 1 is flat.

[0057] In one embodiment, the adhesive includes a first adhesive and a second adhesive. The second adhesive has a lower crystallinity than the first adhesive. The solid electrolyte forms multiple ion transport channels. The second adhesive has a lower crystallinity than the first adhesive, thereby forming a bicrystalline gradient. The high crystallinity of the first adhesive increases tensile strength and thus improves the rigidity of the skeleton, while the low crystallinity of the second adhesive fills microcracks, thereby improving the toughness of the skeleton support layer 1.

[0058] Figure 5 FIG. 1 is a schematic diagram showing a specific embodiment of a method for preparing a solid electrolyte membrane. Specifically, in one embodiment, as Figure 5 As shown, the adhesive includes a first adhesive and a second adhesive, and step 110 includes: Step 111: dissolve Li-β-Al2O3 solid electrolyte, PEO-based lithium salt, PVDF first binder, PVDF second binder and dispersant in NMP to prepare a first slurry.

[0059] Step 120 includes: Step 121: Coat the first slurry on a metal carrier mold, and control the dry film thickness to be any value between 3 μm and 50 μm. In several specific embodiments, the dry film thickness is 3 μm, 6 μm, or 50 μm.

[0060] Figure 6FIG. 1 is a schematic diagram showing another specific embodiment of a method for preparing a solid electrolyte membrane. Specifically, in one embodiment, as Figure 6 As shown, step 150 includes: Step 151: Prepare a second slurry by mixing a PEO-based electrolyte, an inorganic lithium salt LiBF4 and a DEC plasticizer.

[0061] Step 170 includes: Step 171: spray the second slurry onto the surface of the skeleton support layer 1, and control the thickness of the elastic cover layer 3 to be any value between 0.5 μm and 5 μm. In several specific embodiments, the thickness of the elastic cover layer 3 is 0.5 μm, 2 μm, or 5 μm.

[0062] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0063] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0064] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0065] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be applied in the widest sense consistent with the principles and novel features of the present invention.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A solid electrolyte membrane, characterized in that include: The skeleton support layer (1) is provided with a plurality of through holes (101) extending through the thickness direction; Through-hole filling bodies (2) are filled in each of the through-holes (101) in a one-to-one correspondence; as well as an elastic covering layer (3) covering at least one surface of the skeleton support layer (1), wherein the elastic modulus of the elastic covering layer (3) is smaller than the elastic modulus of the skeleton support layer (1); The material of the skeleton support layer (1) is different from the materials of the through-hole filling body (2) and the elastic covering layer (3); the materials of the skeleton support layer (1), the through-hole filling body (2) and the elastic covering layer (3) all include electrically conductive materials.

2. The solid electrolyte membrane according to claim 1, characterized in that The shapes of the plurality of through holes (101) are selected from one or more of the following shapes: a cylindrical through hole, a polygonal through hole, a frustum-shaped through hole, and a through hole whose vertical cross-section profile is a curve; The porosity of the skeleton support layer (1) is greater than 55%, the distance between the geometric centers of adjacent through holes (101) is greater than 50 nm, the diameter or side length of the through holes (101) is any value between 10 nm and 500 nm, and a plurality of the through holes (101) are evenly arranged on the skeleton support layer (1).

3. The solid electrolyte membrane according to claim 1, wherein The number of the elastic covering layers (3) is two, and the two elastic covering layers (3) respectively cover both sides of the skeleton support layer (1).

4. The solid electrolyte membrane according to claim 1, wherein The thickness of the skeleton support layer (1) is any value between 3 μm and 50 μm, and the thickness of the assembly of the skeleton support layer (1) and the elastic covering layer (3) is any value between 4 μm and 60 μm.

5. The solid electrolyte membrane according to claim 1, wherein The skeleton support layer (1) is made of one or more of the following materials: a solid electrolyte, a first binder, a second binder, and a dispersant; The second binder has a lower crystallinity than the first binder.

6. The solid electrolyte membrane according to claim 1, characterized in that The materials used to make the through-hole filling body (2) and the elastic covering layer (3) include: polymer-based electrolyte, inorganic salt and plasticizer.

7. A solid-state battery, characterized in that: Comprising the solid electrolyte membrane according to any one of claims 1 to 6.

8. A method for preparing the solid electrolyte membrane according to any one of claims 1 to 6, characterized in that: include: preparing a first slurry by mixing a solid electrolyte, a binder and a dispersant; coating the first slurry on a carrier mold; Drying and rolling the carrier mold coated with the first slurry, and removing the carrier mold to obtain a skeleton support layer (1); Laser etching the skeleton support layer (1) to prepare a plurality of through holes; preparing a second slurry by mixing a polymer-based electrolyte, an inorganic salt and a plasticizer; spraying the second slurry into the through hole (101) to form a through hole filling body (2); and spraying the second slurry onto the surface of the skeleton support layer (1) to form an elastic covering layer (3); The elastic modulus of the elastic covering layer (3) is smaller than the elastic modulus of the skeleton support layer (1), the material of the skeleton support layer (1) is different from the materials of the through-hole filling body (2) and the elastic covering layer (3), and the materials of the skeleton support layer (1), the through-hole filling body (2) and the elastic covering layer (3) all include electrically conductive materials.

9. The method for preparing a solid electrolyte membrane according to claim 8, wherein: The adhesive includes a first adhesive and a second adhesive, wherein the second adhesive has a lower crystallinity than the first adhesive.

10. The method for preparing a solid electrolyte membrane according to claim 8, wherein: The step of coating the first slurry on the carrier mold comprises: Applying the first slurry on a metal carrier mold, and controlling the dry film thickness to be any value between 3 μm and 50 μm; The step of spraying the second slurry onto the surface of the skeleton support layer (1) to form the elastic covering layer (3) comprises: The second slurry is sprayed onto the surface of the skeleton support layer (1), and the thickness of the elastic covering layer (3) is controlled to be any value between 0.5 μm and 5 μm.

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