Solid-state electrolyte membrane and solid-state battery

Abstract

The present application relates to the technical field of batteries, and provides a solid-state electrolyte membrane and a solid-state battery having the solid-state electrolyte membrane. In the solid-state electrolyte membrane provided in the present application, by means of providing in a first edge region of a first surface and / or a second edge region of a second surface an annular protrusion part that can form a certain gap in a solid-state battery, an accommodating space can be provided for a negative electrode sheet having an increased thickness in use, helping to reduce the expansion rate of the solid-state battery.

Description

Solid electrolyte membranes and solid batteries

[0001] This application claims priority to Chinese Patent Application No. 202421851710.0, filed with the Chinese Patent Office on July 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a solid electrolyte membrane and a solid battery having the solid electrolyte membrane. Background Technology

[0003] Driven by the need for energy conservation and emission reduction, batteries are being used more and more widely. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of batteries continue to expand, the market demand is also constantly increasing.

[0004] Traditional liquid lithium-ion batteries consist of a separator, positive electrode, negative electrode, electrolyte, and carrier. The electrolyte is prone to fire and explosion after thermal runaway, posing safety hazards. Solid-state electrolytes eliminate the flammability, explosion, and leakage problems associated with liquid electrolytes, making them the preferred electrolyte for next-generation batteries. Solid-state electrolytes are inorganic solid materials with high ion conductivity, effectively preventing lithium dendrite formation during charging and discharging, thus improving battery safety and cycle life. Compared to liquid electrolytes, solid-state electrolytes have higher thermal and chemical stability, further enhancing battery safety. Furthermore, solid-state electrolytes exhibit higher electrochemical stability, allowing them to withstand a wider temperature range and more cycle times, extending battery life. In short, the advantages of solid-state electrolytes over traditional liquid electrolytes include higher safety, higher density, better stability, limited lithium dendrite formation, and a wider operating temperature range, significantly improving battery adaptability and reliability.

[0005] However, solid-state batteries also have the problem of large expansion rate. Taking solid-state batteries with lithium metal as negative electrode as an example, the deposition of lithium ions to form lithium metal will cause the overall thickness of the cell to expand during charging. Tests have found that lithium metal batteries have huge expansion force (up to 2000 kgf for large cells). Without external force restraint, the free expansion rate of the cell can reach 30%. At the same time, the cell has the problem of rapid decline in electrical performance, resulting in an unsatisfactory service life. Technical issues Technical solutions

[0006] This application provides a solid electrolyte and a solid battery having the solid electrolyte, aiming to improve or solve at least one of the above-mentioned technical problems.

[0007] On one hand, this application provides a solid electrolyte membrane for use in a solid-state battery, the solid-state battery including a positive electrode and a negative electrode disposed opposite to each other, the positive electrode having a positive active layer and the negative electrode having a negative active layer, the solid electrolyte membrane including a body and a protrusion; the protrusion is annular;

[0008] The body includes a first surface and a second surface disposed opposite to each other, the first surface facing the positive electrode active layer and the second surface facing the negative electrode active layer; the first surface includes a first central region and a first edge region, the first central region being directly opposite the positive electrode active layer; the first edge region is a closed ring, and the first central region is located within the first edge region; the second surface includes a second central region and a second edge region, the second central region being directly opposite the negative electrode active layer, the second edge region being a closed ring, and the second central region is located within the second edge region;

[0009] The protrusion is located in the first edge region and extends along the first edge region; and / or the protrusion is located in the second edge region and extends along the second edge region.

[0010] In one possible implementation of this application, the protrusion includes a first protrusion layer and a second protrusion layer, both of which are arranged in a ring shape. The first protrusion layer is located in the first edge region and extends along the first edge region; the second protrusion layer is located in the second edge region and extends along the second edge region.

[0011] In one possible implementation of this application, the thickness of the first protrusion is 4 μm to 130 μm; and / or

[0012] The thickness of the second protrusion is 4 μm to 130 μm.

[0013] In one possible implementation of this application, the body and the protrusion are an integral structure; and / or

[0014] The protrusion located on the first edge region is a closed ring; and / or

[0015] The protrusion located on the second edge region is a closed ring; and / or

[0016] The material used to prepare the protrusion is selected from one of ceramics, polyimide, and polypropylene.

[0017] A second aspect of this application provides a solid-state battery, the solid-state battery comprising a positive electrode, a negative electrode, and a solid electrolyte membrane, wherein the positive electrode, the solid electrolyte, and the negative electrode are stacked sequentially.

[0018] In one possible implementation of this application, the positive electrode is selected from lithium iron phosphate positive electrode and lithium cobalt oxide positive electrode.

[0019] In one possible implementation of this application,

[0020] The protrusion includes a first protrusion layer located on the first edge region;

[0021] If the positive electrode is a lithium iron phosphate positive electrode, the thickness of the first bump layer is 4 μm to 110 μm; or

[0022] If the positive electrode is a lithium cobalt oxide positive electrode, the thickness of the first bump layer is 4 μm to 130 μm.

[0023] In one possible implementation of this application, the negative electrode is selected from graphite negative electrode, silicon-carbon negative electrode, and lithium metal negative electrode.

[0024] In one possible implementation of this application,

[0025] The protrusion includes a second protrusion layer located on the second edge region;

[0026] If the negative electrode is a graphite negative electrode, the thickness of the second protrusion layer is 4 μm to 90 μm; or

[0027] If the negative electrode is a silicon-carbon negative electrode, the thickness of the second bump layer is 4 μm to 130 μm; or

[0028] If the negative electrode is a lithium metal negative electrode, the thickness of the second bump layer is 4 μm to 130 μm.

[0029] In one possible implementation of this application, the solid-state battery is a pouch cell. Beneficial effects

[0030] This application provides a solid electrolyte membrane. By providing protrusions in a first edge region of a first surface and / or a second edge region of a second surface, and these protrusions being annular, the protrusions, when used in a solid-state battery, can form a certain gap within the solid-state battery. This gap provides space to accommodate the negative electrode sheet, which thickens during use, thus reducing the expansion rate of the solid-state battery. Furthermore, the protrusions can prevent lithium ions from diffusing from the first or second central region to the first or second edge region, improving or preventing the degradation of the solid-state battery's electrical performance caused by lithium ion diffusion from the first or second central region to the first or second edge region, thereby increasing the lifespan of the solid-state battery. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 is a schematic diagram of the stacked structure of the positive electrode, solid electrolyte membrane and negative electrode in the solid-state battery provided in the embodiment of this application;

[0033] Figure 2 is a schematic diagram of the stacked structure of the positive electrode, solid electrolyte membrane and negative electrode in Figure 1 from another perspective;

[0034] Figure 3 is a schematic diagram of the exploded structure of the positive electrode, solid electrolyte membrane and negative electrode in the solid-state battery provided in the application embodiment;

[0035] Figure 4 is a structural schematic diagram of the first embodiment of the solid electrolyte membrane provided in the application;

[0036] Figure 5 is a schematic diagram of the structure of the second embodiment of the solid electrolyte membrane provided in the application.

[0037] Reference numerals: 10. Solid electrolyte membrane; 11. Body; 111. First central region; 113. Second central region; 12. Protrusion; 121. First convex layer; 122. Second convex layer; 13. Negative electrode; 131. Negative electrode tab; 14. Positive electrode; 141. Positive electrode tab. Embodiments of the present invention

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0042] Traditional liquid lithium-ion batteries consist of a positive electrode, a separator, a negative electrode, an electrolyte, and a casing.

[0043] The positive electrode includes a positive current collector and a positive active layer located on the current collector. The positive active layer includes a positive active material. For example, the positive active material is generally lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, or lithium nickel cobalt manganese oxide. The positive electrode is the part of the battery with a high potential, and a chemical reaction occurs on the positive electrode during the charging and discharging process of the lithium battery.

[0044] The negative electrode includes a negative current collector and a negative active layer located on the negative current collector. The negative active layer includes a negative active material. For example, the negative active material is generally graphite or other carbon materials with a similar graphite structure. The negative electrode is the part of the battery with the lowest potential; during the charging and discharging process of the lithium battery, the negative electrode stores and releases lithium ions.

[0045] The electrolyte plays a crucial role in conducting lithium ions between the positive and negative electrodes of a lithium battery, ensuring a high and stable voltage. For example, the electrolyte typically consists of a carbonate-based organic solvent, lithium hexafluorophosphate, and some additives.

[0046] The primary function of the separator is to isolate the positive and negative electrodes while allowing lithium ions to pass through and form a closed loop. Located between the positive and negative electrodes, the separator prevents direct contact and short circuits, while allowing lithium ions to pass through. Separators are typically made of polyethylene (PE), polypropylene (PP), or composite films thereof. Lithium-ion battery separators have numerous interconnected micropores, ensuring free passage of lithium ions to form a charge-discharge circuit. When the battery is overcharged or the temperature rises, the separator, through its closed-pore function, separates the positive and negative electrodes to prevent direct contact and short circuits, thus blocking current conduction and preventing overheating or even explosion. Therefore, the performance of the lithium-ion separator effectively affects the safety, charge-discharge, and cycle performance of lithium batteries, making it one of the most critical components. The separator material is non-conductive, and its physicochemical properties significantly influence battery performance. The performance of the separator in a liquid lithium-ion battery determines the battery's interface structure, internal resistance, etc., directly affecting its capacity, cycle life, and safety characteristics. A high-performance separator plays a crucial role in improving the overall performance of the battery.

[0047] The outer casing protects the internal structure of the battery and serves as its encapsulation. It primarily consists of an aluminum shell, cover plate, tabs, and insulating sheets, ensuring the battery's safety and stability.

[0048] It's important to note that electrolytes are prone to fire and explosion after battery thermal runaway, posing safety hazards. Solid-state electrolytes eliminate the flammability, explosion, and leakage problems associated with liquid electrolytes, making them the preferred electrolyte for next-generation batteries. Solid-state electrolytes are inorganic solid materials with high ion conductivity, effectively preventing lithium dendrite formation during lithium battery charging and discharging, thus improving battery safety and cycle life. Compared to liquid electrolytes, solid-state electrolytes exhibit higher thermal and chemical stability, further enhancing battery safety. Furthermore, solid-state electrolytes possess higher electrochemical stability, allowing them to withstand a wider temperature range and more cycle times, extending battery lifespan. In short, the advantages of solid-state electrolytes over traditional liquid electrolytes include higher safety, higher density, better stability, limited lithium dendrite formation, and a wider operating temperature range. These advantages significantly improve battery adaptability and reliability.

[0049] However, solid-state batteries also have the problem of large expansion rate. Taking solid-state batteries with lithium metal as negative electrode as an example, the deposition of lithium ions to form lithium metal will cause the overall thickness of the cell to expand during charging. Tests have found that lithium metal batteries have huge expansion force (up to 2000 kgf for large cells). Without external force restraint, the free expansion rate of the cell can reach 30%. At the same time, the cell has the problem of rapid decline in electrical performance, resulting in an unsatisfactory service life.

[0050] Given that existing solid-state batteries have at least one of the above-mentioned technical problems.

[0051] This application provides a solid electrolyte and a solid battery having the solid electrolyte. By providing a protrusion in the first edge region of the first surface and / or the second edge region of the second surface of the solid electrolyte membrane, and the protrusion being annular, when the solid electrolyte membrane in this application is used in a solid battery, the protrusion can form a certain gap inside the solid battery. This gap can provide a space to accommodate the negative electrode sheet whose thickness increases during use, which is beneficial to reducing the expansion rate of the solid battery.

[0052] Furthermore, the inventors discovered that during storage or use, lithium ions diffuse from the negative electrode to the periphery of the positive electrode, leading to self-discharge or a decrease in overall performance. This application addresses this issue by providing protrusions that prevent lithium ions from diffusing from the first or second central region to the first or second edge region, thus mitigating or preventing the performance degradation caused by lithium ion diffusion and improving the lifespan of the solid-state battery.

[0053] The solid electrolyte membrane and the solid battery having the solid electrolyte membrane in this application will be described in detail below with reference to specific embodiments.

[0054] Please refer to Figures 1 to 5. This application embodiment provides a solid-state battery, which includes a positive electrode 14, a negative electrode 13, and a solid electrolyte membrane 10 disposed opposite to each other. The solid electrolyte membrane 10 is disposed between the positive electrode 14 and the negative electrode 13, that is, the positive electrode 14, the solid electrolyte, and the negative electrode 13 are stacked sequentially.

[0055] For example, the solid-state battery is a pouch-pack aluminum-plastic film structure solid-state battery. Of course, the casing of a solid-state battery can also be an aluminum casing, a plastic casing, a steel casing, etc., and is not limited here. Unless otherwise specified, the solid-state batteries mentioned below all refer to pouch-pack aluminum-plastic film structure solid-state batteries.

[0056] In some embodiments of this application, the positive electrode sheet 14 is provided with a positive electrode active layer. Exemplarily, the positive electrode sheet 14 includes a positive electrode current collector and a positive electrode active layer disposed on the surface of the positive electrode current collector. For example, the positive electrode active layer covers the portion of the positive electrode current collector except for the positive electrode tab 141.

[0057] In some embodiments of this application, the negative electrode sheet 13 is provided with a negative electrode active layer. Exemplarily, the negative electrode sheet 13 includes a negative electrode current collector and a negative electrode active layer disposed on the surface of the negative electrode current collector. For example, the negative electrode active layer covers the portion of the negative electrode current collector except for the negative electrode tab 131.

[0058] In some embodiments of this application, the solid electrolyte membrane 10 includes a body 11, the body 11 including a first surface and a second surface disposed opposite to each other, the first surface facing the positive electrode active layer (i.e., facing the positive electrode sheet 14), and the second surface facing the negative electrode active layer (i.e., facing the negative electrode sheet 13).

[0059] In some embodiments of this application, referring to FIG5, the first surface includes a first central region 111 and a first edge region. The first central region 111 is disposed directly opposite the positive electrode active layer, and the first edge region is a closed ring. The first central region 111 is located within the first edge region. The first central region 111 is also the area on the first surface covered by the positive electrode active layer, that is, the orthogonal projection area of ​​the positive electrode active layer on the solid electrolyte membrane 10. The first edge region is the area on the first surface other than the first central region 111.

[0060] It should be noted that the positive electrode sheet 14, the negative electrode sheet 13, and the solid electrolyte membrane 10 are all generally in a planar laminated structure. To prevent the direct contact between the positive electrode sheet 14 and the negative electrode sheet 13, the area of the solid electrolyte membrane 10 is slightly larger than that of the positive electrode sheet 14, and the area of the solid electrolyte membrane 10 is also slightly larger than that of the negative electrode sheet 13. Exemplarily, the positive electrode sheet 14 (i.e., the part of the positive electrode sheet 14 excluding the positive electrode tab 141) is a square with a side length of 10 mm * 10 mm, that is, the positive electrode active layer is a square with a side length of 10 mm * 10 mm, the solid electrolyte membrane 10 is a square with a side length of 12 mm * 12 mm, and the positive electrode sheet 14 is laminated at the middle position on the solid electrolyte membrane 10 (i.e., the center of the square region in the positive electrode sheet 14 is projected onto the center of the solid electrolyte membrane 10, and the outer contour line of the square region in the positive electrode sheet 14 is parallel to the outer contour line of the solid electrolyte membrane 10). Then, the center of the first central region 111 coincides with the center of the solid electrolyte membrane 10, the first central region 111 is a square with a side length of 10 mm * 10 mm, and the first edge region is the region between a square with a side length of 12 mm * 12 mm (i.e., the region enclosed by the outer contour line of the solid electrolyte membrane 10) and a square with a side length of 10 mm * 10 mm (i.e., the region covered by the positive electrode active layer on the first surface) within it.

[0061] In some embodiments of the present application, referring to FIG. 4, the second surface includes a second central region 113 and a second edge region. The second central region 113 is disposed opposite to the negative electrode active layer, the second edge region is in a closed ring shape, and the second central region 113 is located within the second edge region. Similarly, the second central region 113 is also the region on the second surface covered by the negative electrode active layer, that is, the region where the negative electrode active layer is projected onto the solid electrolyte membrane 10. The second edge region is the region on the second surface except the second central region 113.

[0062] In some embodiments of the present application, referring to FIG. 5, the protrusion 12 (i.e., the first convex layer 121) is located in the first edge region and extends along the first edge region. Exemplarily, the protrusion 12 (i.e., the first convex layer 121) covers the first edge region, the first edge region is in the shape of the Chinese character "回" (hui), and the protrusion 12 (i.e., the first convex layer 121) is also in the shape of the Chinese character "回" (hui). In this way, it is beneficial to improve the effect of the protrusion 12 blocking the diffusion of lithium ions from the first central region 111 or the second central region 113 to the first edge region or the second edge region, and to improve or avoid the diffusion of lithium ions from the first central region 111 or the second central region 113 to the first edge region or the second edge region.

[0063] In an embodiment of the present application, a raised portion 12 (i.e., a first raised layer 121) is provided in a first edge region of a first surface, and the raised portion 12 (i.e., the first raised layer 121) is annular. Thus, when the solid electrolyte membrane 10 in the present application is used in a solid-state battery, the raised portion 12 can form a certain gap in the solid-state battery, and this gap can provide a accommodation space for the negative electrode sheet 13 whose thickness increases during use, which is beneficial to reducing the expansion rate of the solid-state battery. In addition, the raised portion 12 can block the diffusion of lithium ions from the first central region 111 to the first edge region and the second edge region, and from the second central region 113 to the first edge region, thereby improving the electrical performance of the solid-state battery.

[0064] In some embodiments of the present application, please refer to FIGS. 4 and 5. The difference between FIG. 4 and FIG. 5 is that in FIG. 4, only a second raised layer 122 is provided on the second surface of the solid electrolyte 10, while in FIG. 5, a first raised layer 121 is provided on the first surface of the solid electrolyte 10, and a second raised layer 122 is provided on the second surface. The raised portion 12 (i.e., the second raised layer 122) is located in the second edge region and extends along the second edge region. Exemplarily, the raised portion 12 covers the second edge region, the second edge region is in the shape of the Chinese character "hui", and the raised portion 12 is also in the shape of the Chinese character "hui". Thus, it is beneficial to improve the effect that the raised portion 12 blocks the diffusion of lithium ions from the first central region 111 or the second central region 113 to the first edge region or the second edge region, and to improve or avoid the diffusion of lithium ions from the first central region 111 or the second central region 113 to the first edge region or the second edge region.

[0065] In an embodiment of the present application, a raised portion 12 (i.e., a second raised layer 122) is provided in a second edge region of a second surface, and the raised portion 12 is annular. Thus, when the solid electrolyte membrane 10 in the present application is used in a solid-state battery, the raised portion 12 can form a certain gap in the solid-state battery, and this gap can provide a accommodation space for the negative electrode sheet 13 whose thickness increases during use, which is beneficial to reducing the expansion rate of the solid-state battery. In addition, the raised portion 12 can block the diffusion of lithium ions from the second central region 113 to the first edge region and the second edge region, and from the first central region 111 to the second edge region, thereby improving the electrical performance of the solid-state battery.

[0066] In summary, this application provides a solid electrolyte membrane 10. By providing protrusions 12 in the first edge region of the first surface and / or the second edge region of the second surface, and the protrusions 12 being annular, when the solid electrolyte membrane 10 is used in a solid-state battery, the protrusions 12 can form a certain gap within the solid-state battery. This gap can provide space for the negative electrode sheet 13, whose thickness increases during use, thus helping to reduce the expansion rate of the solid-state battery. Furthermore, the protrusions 12 can prevent lithium ions from diffusing from the first central region 111 or the second central region 113 to the first edge region or the second edge region, improving or avoiding the problem of lithium ions diffusing from the first central region 111 or the second central region 113 to the first edge region or the second edge region, thereby improving the electrical performance of the solid-state battery.

[0067] In some embodiments of this application, please refer to FIG5. The protrusion 12 includes a first protrusion 121 and a second protrusion 122. The first protrusion 121 and the second protrusion 122 are both arranged in a ring. The first protrusion 121 is located in the first edge region and extends along the first edge region; the second protrusion 122 is located in the second edge region and extends along the second edge region.

[0068] This embodiment, by providing a first protrusion 121 on the first surface and a second protrusion 122 on the second surface, facilitates an increase in the number of gaps within the solid-state battery, thereby increasing the volume of the accommodating space and further reducing the expansion rate of the solid-state battery. Furthermore, providing protrusions 12 on both surfaces of the solid electrolyte membrane 10 helps to further improve or prevent lithium ions from diffusing from the first central region 111 or the second central region 113 to the first edge region or the second edge region, thereby further improving the electrical performance of the solid-state battery.

[0069] In some embodiments of this application, the thickness of the first protrusion 121 is between 4 μm and 130 μm. It should be noted that the thickness of the first protrusion 121 refers to its dimension on a plane perpendicular to the body 11. It is understood that if the thickness of the first protrusion 121 is too small, for example, less than 4 μm, the volume of the accommodating space it forms within the battery is small, and its effect in improving or preventing lithium ion diffusion from the first central region 111 or the second central region 113 to the first edge region or the second edge region is not significant. If the thickness of the first protrusion 121 is too small, for example, greater than 130 μm, it easily leads to a larger solid-state battery volume.

[0070] For example, the thickness of the first convex layer 121 is 4μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, or 130μm.

[0071] It should be noted that the thickness of the first protrusion 121 is also related to the positive electrode active material. In some embodiments of this application, the positive electrode 14 is selected from either a lithium iron phosphate positive electrode 14 or a lithium cobalt oxide positive electrode 14. Specifically, if the positive electrode 14 is a lithium iron phosphate positive electrode 14 (i.e., the active material of the positive electrode 14 is lithium iron phosphate), the thickness of the protrusion 12 (i.e., the first protrusion 121) located on the first edge region is 4 μm to 110 μm. If the positive electrode 14 is a lithium cobalt oxide positive electrode 14 (i.e., the active material of the positive electrode 14 is lithium cobalt oxide), the thickness of the first protrusion 121 of the protrusion 12 located on the first edge region is 4 μm to 130 μm.

[0072] In some embodiments of this application, the thickness of the second bump layer 122 is between 4 μm and 130 μm. It should be noted that the thickness of the second bump layer 122 refers to its dimension on a plane perpendicular to the body 11. It is understood that if the thickness of the second bump layer 122 is too small, for example, less than 4 μm, the volume of the accommodating space it forms within the battery is small, and its effect in improving or preventing lithium ion diffusion from the first central region 111 or the second central region 113 to the first edge region or the second edge region is not significant. If the thickness of the second bump layer 122 is too small, for example, greater than 130 μm, it easily leads to a larger solid-state battery volume.

[0073] For example, the thickness of the second convex layer 122 is 4μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, or 130μm.

[0074] It should be noted that the thickness of the second protrusion 122 is also related to the negative electrode active material. In some embodiments of this application, the negative electrode 13 is selected from graphite negative electrode 13, silicon-carbon negative electrode 13, and lithium metal negative electrode 13. Specifically, if the negative electrode 13 is a graphite negative electrode 13 (that is, the active material of the negative electrode 13 is graphite), the thickness of the protrusion 12 located on the second edge region is 4 μm to 90 μm. If the negative electrode 13 is a silicon-carbon negative electrode 13 (that is, the active material of the negative electrode 13 is silicon-carbon), the thickness of the protrusion 12 located on the second edge region is 4 μm to 130 μm. If the negative electrode 13 is a lithium metal negative electrode 13 (that is, the active material of the negative electrode 13 is lithium metal), the thickness of the protrusion 12 located on the first edge region is 4 μm to 130 μm.

[0075] In some embodiments of this application, the body 11 and the protrusion 12 are an integral structure. This is beneficial for improving the connection force between the protrusion 12 and the body 11.

[0076] In some embodiments of this application, the protrusion 12 can be formed by processes such as coating, bonding, deposition, 3D printing, and chemical etching. Exemplarily, the protrusion 12 can be integrally formed onto the body 11 using processes such as coating, bonding, deposition, 3D printing, and chemical etching. This helps to improve the connection between the protrusion 12 and the body 11.

[0077] In some embodiments of this application, the protrusion 12 located on the first edge region is a closed ring. This is beneficial to improving the effect of the protrusion 12 in preventing lithium ions from diffusing from the first central region 111 to the first and second edge regions, and from the second central region 113 to the first edge region.

[0078] In some embodiments of this application, the protrusion 12 located on the second edge region is a closed ring. This is beneficial to improving the effect of the protrusion 12 in preventing lithium ions from diffusing from the second central region 113 to the first and second edge regions, and from the first central region 111 to the second edge region.

[0079] In some embodiments of this application, to avoid mutual corrosion between the solid electrolyte membrane 10 and the positive and negative electrode sheets 13 and to improve the stability of the solid-state battery, the material used to prepare the protrusion 12 does not react with the material used to prepare the body 11, the positive electrode sheet 14, and the negative electrode sheet 13. Exemplarily, the material used to prepare the protrusion 12 is selected from ceramics, polyimide, and polypropylene.

[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0081] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0082] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0083] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0084] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such numerical values ​​are set as precisely as feasible.

[0085] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A solid-state electrolyte membrane for a solid-state battery, the solid-state battery comprising a positive electrode sheet and a negative electrode sheet disposed opposite each other, the positive electrode sheet having a positive electrode active layer provided thereon, and the negative electrode sheet having a negative electrode active layer provided thereon, wherein, The solid-state electrolyte film comprises a body and a protruding part; the protruding part is annular; The body comprises oppositely arranged first and second surfaces, the first surface faces the positive active layer, and the second surface faces the negative active layer; the first surface comprises a first central region and a first edge region, the first central region is arranged opposite to the positive active layer; the first edge region is annular and closed, and the first central region is located in the first edge region; the second surface comprises a second central region and a second edge region, the second central region is arranged opposite to the negative active layer, and the second edge region is annular and closed, and the second central region is located in the second edge region; The protruding part is located in the first edge region and extends along the first edge region; and / or the protruding part is located in the second edge region and extends along the second edge region.

2. The solid-state electrolyte film of claim 1, wherein, The protruding part comprises a first protruding layer and a second protruding layer, both of which are annular; the first protruding layer is located in the first edge region and extends along the first edge region; and the second protruding layer is located in the second edge region and extends along the second edge region.

3. The solid-state electrolyte film of claim 2, wherein, The thickness of the first protruding layer is 4-130 μm.

4. The solid-state electrolyte film of claim 2, wherein, The thickness of the second protruding layer is 4-130 μm.

5. The solid-state electrolyte film of claim 1, wherein, The body and the protruding part are of an integral structure.

6. The solid-state electrolyte film of claim 1, wherein, The protruding part on the first edge region is annular and closed.

7. The solid-state electrolyte film of claim 1, wherein, The protruding part on the second edge region is annular and closed.

8. The solid-state electrolyte film of claim 1, wherein, The material for preparing the protruding part is selected from one of ceramic, polyimide and polypropylene.

9. A solid-state battery, wherein, The solid-state battery comprises a positive electrode sheet, a negative electrode sheet and the solid-state electrolyte film according to any one of claims 1-8, which are sequentially stacked.

10. The solid-state battery of claim 9, wherein, The positive electrode sheet is selected from one of lithium iron phosphate positive electrode sheet and lithium cobaltate positive electrode sheet.

11. The solid-state battery of claim 10, wherein, The protruding part comprises a first protruding layer on the first edge region.

12. The solid-state battery of claim 11, wherein, The positive electrode sheet is a lithium iron phosphate positive electrode sheet, and the thickness of the first protruding layer is 4-110 μm.

13. The solid-state battery of claim 11, wherein, The positive electrode sheet is a lithium cobaltate positive electrode sheet, and the thickness of the first protruding layer is 4-130 μm.

14. The solid-state battery of claim 9, wherein, The negative electrode sheet is selected from one of graphite negative electrode sheet, silicon-carbon negative electrode sheet and lithium metal negative electrode sheet.

15. The solid-state battery of claim 10, wherein, The protruding part comprises a second protruding layer on the second edge region.

16. The solid-state battery of claim 15, wherein, The negative electrode sheet is a graphite negative electrode sheet, and the thickness of the second protruding layer is 4-90 μm.

17. The solid-state battery of claim 15, wherein, The negative electrode sheet is a silicon-carbon negative electrode sheet, and the thickness of the second protruding layer is 4-130 μm.

18. The solid-state battery of claim 15, wherein, The negative electrode sheet is a lithium metal negative electrode sheet, and the thickness of the second protruding layer is 4-130 μm.

19. The solid-state battery of claim 9, wherein, The solid-state battery is a soft package battery.

20. The solid-state battery of claim 9, wherein, The solid-state battery is a soft package aluminum-plastic film structure solid-state battery.

Images