Solid electrolyte membrane and solid-state battery

Abstract

The utility model provides a solid-state electrolyte membrane and a solid-state battery with the solid-state electrolyte membrane, and relates to the technical field of batteries. According to the solid-state electrolyte membrane provided by the invention, the lug bosses are arranged in the first edge area of the first surface and / or the second edge area of the second surface, and the lug bosses are annular, so that when the solid-state electrolyte membrane is used for a solid-state battery, the lug bosses can form a certain gap in the solid-state battery, and the solid-state battery can be prevented from being damaged. And the gap can provide an accommodating space for the negative plate with increased thickness in the use process, so that the expansion rate of the solid-state battery can be reduced. In addition, the lug bosses can prevent lithium ions from diffusing from the first central region or the second central region to the first edge region or the second edge region, so that the problem that the lithium ions are diffused from the first central region or the second central region to the first edge region or the second edge region to cause the reduction of the electrical performance of the solid-state battery is solved or avoided; therefore, the service life of the solid-state battery is prolonged.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to a solid electrolyte membrane and a solid-state battery having the solid electrolyte membrane. Background Art

[0002] Due to the demand for energy conservation and emission reduction, batteries are increasingly widely used. Batteries are not only applied to energy storage power systems such as hydraulic, thermal, wind, and solar power stations, but also widely used in electric transportation tools such as electric bicycles, electric motorcycles, and electric vehicles, as well as in multiple fields such as aerospace. With the continuous expansion of the battery application field, the market demand is also continuously increasing.

[0003] Traditional liquid lithium-ion batteries are composed of a separator, a positive electrode sheet, a negative electrode sheet, an electrolyte, and a carrier. Among them, the electrolyte is prone to safety hazards such as fire and explosion after the battery thermal runaway. Solid electrolytes can eliminate problems such as flammability, explosiveness, and leakage caused by liquid electrolytes, and are the preferred electrolytes for next-generation batteries. Solid electrolytes are inorganic solid materials with high ionic conductivity, which can effectively prevent the lithium dendrite problem occurring during the charge and discharge process of lithium batteries, improving the safety and cycle life of the batteries. Compared with liquid electrolytes, solid electrolytes have higher thermal stability and chemical stability, thereby improving the safety of the batteries to a certain extent. In addition, solid electrolytes also have high electrochemical stability, can withstand a wider temperature range and cycle times, and extend the service life of the batteries. That is, the advantages of solid electrolytes compared with traditional liquid electrolytes include higher safety, higher density, better stability, restriction of the generation of lithium dendrites, and a higher working temperature range, and these advantages significantly improve the adaptability and reliability of the batteries.

[0004] However, solid-state batteries also have the problem of a relatively large expansion rate. Taking a solid-state battery with a lithium metal negative electrode sheet as an example, since the deposition of lithium ions forms lithium metal, it will cause the overall thickness of the battery cell to expand during charging. Tests have found that the expansion force of lithium metal batteries is huge (up to 2000 kgf for large battery cells), and without external force restraint, the free expansion rate of the battery cell can reach 30%; at the same time, the battery cell has the problem that the electrical performance drops too fast, resulting in an unsatisfactory service life. Utility Model Content

[0005] This application provides a solid electrolyte and a solid-state battery having the solid electrolyte, aiming to improve or solve at least one of the above technical problems.

[0006] On the one hand, this application provides a solid electrolyte membrane for a solid-state battery. The solid-state battery includes a positive electrode sheet and a negative electrode sheet arranged oppositely. The positive electrode sheet is provided with a positive electrode active layer, and the negative electrode sheet is provided with a negative electrode active layer. The solid electrolyte membrane includes a main body and a convex portion; the convex portion is annular;

[0007] The body includes a first surface and a second surface which are oppositely arranged, the first surface faces the positive electrode active layer, and the second surface faces the negative electrode active layer; the first surface includes a first central region and a first edge region, the first central region is arranged opposite to the positive electrode active layer; the first edge region is in a closed annular shape, 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 is arranged opposite to the negative electrode active layer, the second edge region is in a closed annular shape, and the second central region is located within the second edge region;

[0008] The raised portion is located in the first edge region and extends along the first edge region; and / or the raised portion is located in the second edge region and extends along the second edge region.

[0009] In a possible implementation manner of the present application, the raised portion includes a first convex layer and a second convex layer, both the first convex layer and the second convex layer are in an annular shape, the first convex layer is located in the first edge region and extends along the first edge region; the second convex layer is located in the second edge region and extends along the second edge region.

[0010] In a possible implementation manner of the present application, the thickness of the first convex layer is 4 μm to 130 μm; and / or

[0011] The thickness of the second convex layer is 4 μm to 130 μm.

[0012] In a possible implementation manner of the present application, the body and the raised portion are of an integral structure; and / or

[0013] The raised portion located in the first edge region is in a closed annular shape; and / or

[0014] The raised portion located in the second edge region is in a closed annular shape; and / or

[0015] The material for preparing the raised portion is selected from one of ceramics, polyimide, and polypropylene.

[0016] The second aspect of the present application provides a solid-state battery, the solid-state battery includes a positive electrode sheet, a negative electrode sheet, and the solid electrolyte film as described above, and the positive electrode sheet, the solid electrolyte, and the negative electrode sheet are stacked in sequence.

[0017] In a possible implementation manner of the present application, the positive electrode sheet is selected from one of a lithium iron phosphate positive electrode sheet and a lithium cobaltate positive electrode sheet.

[0018] In a possible implementation manner of the present application,

[0019] The raised portion includes a first raised layer located on the first edge region;

[0020] If the positive electrode sheet is a lithium iron phosphate positive electrode sheet, the thickness of the first raised layer is 4 μm to 110 μm; or

[0021] If the positive electrode sheet is a lithium cobalt oxide positive electrode sheet, the thickness of the first raised layer is 4 μm to 130 μm.

[0022] In a possible implementation manner of the present application, the negative electrode sheet is selected from one of a graphite negative electrode sheet, a silicon-carbon negative electrode sheet, and a lithium metal negative electrode sheet.

[0023] In a possible implementation manner of the present application,

[0024] The raised portion includes a second raised layer located on the second edge region;

[0025] If the negative electrode sheet is a graphite negative electrode sheet, the thickness of the second raised layer is 4 μm to 90 μm; or

[0026] If the negative electrode sheet is a silicon-carbon negative electrode sheet, the thickness of the second raised layer is 4 μm to 130 μm ; or

[0027] If the negative electrode sheet is a lithium metal negative electrode sheet, the thickness of the second raised layer is 4 μm to 130 μm .

[0028] In a possible implementation manner of the present application, the solid-state battery is a soft-pack battery.

[0029] In the present application, a solid-state electrolyte membrane is provided. By providing raised portions on the first edge region of the first surface and / or the second edge region of the second surface, and the raised portions are annular, when the solid-state electrolyte membrane in the present application is used in a solid-state battery, the raised portions can form a certain gap in the solid-state battery, and this gap can provide a accommodation space for the negative electrode sheet whose thickness increases during use, which is beneficial to reducing the expansion rate of the solid-state battery. In addition, the raised portions can block the diffusion of lithium ions from the first central region or the second central region to the first edge region or the second edge region, improving or avoiding the problem of the decline in the electrical performance of the solid-state battery caused by the diffusion of lithium ions from the first central region or the second central region to the first edge region or the second edge region, thereby improving the service life of the solid-state battery. Description of the Drawings

[0030] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is a schematic diagram of the stacked structure of the positive electrode sheet, the solid electrolyte membrane, and the negative electrode sheet in the solid-state battery provided by the embodiment of the present application;

[0032] Figure 2 is Figure 1 a schematic diagram of the stacked structure of the positive electrode sheet, the solid electrolyte membrane, and the negative electrode sheet in another perspective in

[0033] Figure 3 It is an exploded structure schematic diagram of the positive electrode sheet, the solid electrolyte membrane, and the negative electrode sheet in the solid-state battery provided by the embodiment of the application;

[0034] Figure 4 It is a schematic diagram of the structure of the first embodiment of the solid electrolyte membrane provided by the embodiment of the application;

[0035] Figure 5 It is a schematic diagram of the structure of the second embodiment of the solid electrolyte membrane provided by the embodiment of the application.

[0036] Reference numerals:

[0037] 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 sheet; 131. Negative electrode tab; 14. Positive electrode sheet; 141. Positive electrode tab. Detailed implementation manners

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0039] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "a plurality" is two or more unless otherwise specifically defined.

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

[0042] A traditional liquid lithium-ion battery is composed of a positive electrode plate, a separator, a negative electrode plate, an electrolyte, and a casing.

[0043] Among them, the positive electrode plate includes a positive electrode current collector and a positive electrode active layer located on the positive electrode current collector. The positive electrode active layer includes positive electrode active materials. Exemplarily, the positive electrode active materials are generally materials such as lithium cobalt oxide, lithium manganate, lithium iron phosphate, or lithium nickel cobalt manganate. The positive electrode plate is the part with a relatively high potential in the battery. During the charge and discharge process of the lithium battery, chemical reactions will occur on the positive electrode plate.

[0044] Among them, the negative electrode plate includes a negative electrode current collector and a negative electrode active layer located on the negative electrode current collector. The negative electrode active layer includes negative electrode active materials. Exemplarily, the negative electrode active materials are generally graphite or other carbon materials with a structure similar to graphite. The negative electrode plate is the part with a relatively low potential in the battery. During the charge and discharge process of the lithium battery, the negative electrode plate will store and release lithium ions.

[0045] Among them, the electrolyte plays a role in conducting lithium ions between the positive and negative electrodes of the lithium battery, ensuring that the lithium battery has a high and stable voltage. Exemplarily, the electrolyte generally consists of carbonate organic solvents, lithium hexafluorophosphate, and some additives.

[0046] Among them, the main function of the separator is to isolate the positive and negative electrodes and allow lithium ions to pass through to form a closed loop. The separator is located between the positive and negative electrodes, preventing the direct contact between the positive and negative electrodes from causing a short circuit, while allowing lithium ions to pass through. The separator is usually made of polyethylene (PE), polypropylene (PP), or their composite film. The lithium-ion battery separator has a large number of tortuous and through micropores, which can ensure the free passage of lithium ions to form a charge-discharge circuit; when the battery is overcharged or the temperature rises, the separator separates the positive and negative electrodes of the battery through the closed-pore function to prevent their direct contact and short circuit, achieving the effect of blocking current conduction and preventing the battery from overheating or even exploding. Therefore, the performance of the lithium-ion separator can effectively affect the safety, charge-discharge, and cycle performance of the lithium battery, and it is one of the most critical components. The separator material is non-conductive, and its physical and chemical properties have a great impact on the performance of the battery. The performance of the separator of the liquid lithium-ion battery determines the interface structure, internal resistance, etc. of the battery, directly affecting the characteristics such as the capacity, cycle, and safety performance of the battery. A separator with excellent performance plays an important role in improving the comprehensive performance of the battery.

[0047] Among them, the outer shell is used to protect the internal structure of the battery and serves as the encapsulation part of the battery. The outer shell mainly consists of an aluminum shell, a cover plate, electrode tabs, insulating sheets, etc., ensuring the safety and stability of the battery.

[0048] It should be noted that the electrolyte is prone to safety hazards such as fire and explosion after the thermal runaway of the battery. The solid electrolyte can eliminate the problems of flammability, easy explosion, and leakage caused by the liquid electrolyte, and it is the preferred electrolyte for the next-generation battery. The solid electrolyte is an inorganic solid material with high ionic conductivity, which can effectively prevent the lithium dendrite problem that occurs during the charge-discharge process of the lithium battery, improving the safety and cycle life of the battery. Compared with the liquid electrolyte, the solid electrolyte has higher thermal stability and chemical stability, thus improving the safety of the battery to a certain extent. In addition, the solid electrolyte also has high electrochemical stability, can withstand a wider temperature range and cycle times, and extends the service life of the battery. That is to say, the advantages of the solid electrolyte compared with the traditional liquid electrolyte include higher safety, higher density, better stability, limitation of the generation of lithium dendrites, and a higher working temperature range, and these advantages significantly improve the adaptability and reliability of the battery.

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

[0050] In view of the above at least one technical problem existing in the existing solid-state batteries.

[0051] The embodiment of the present application provides a solid electrolyte and a solid-state 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 is annular, when the solid electrolyte membrane in the present application is used for a solid-state battery, the protrusion can form a certain gap in the solid-state battery, and this gap can provide a accommodation space for the negative electrode that increases in thickness during use, which is beneficial to reducing the expansion rate of the solid-state battery.

[0052] In addition, the inventors have found through research that during the storage or use of the battery cell, lithium ions will diffuse around the outer contour of the positive electrode facing the negative electrode, resulting in self-discharge of the battery cell or a decline in the comprehensive use performance. In the present application, by providing a protrusion, the protrusion can block the diffusion of lithium ions from the first central region or the second central region to the first edge region or the second edge region, improving or avoiding the problem of the decline in the electrical performance of the solid-state battery caused by the diffusion of lithium ions from the first central region or the second central region to the first edge region or the second edge region, thereby improving the service life of the solid-state battery.

[0053] The following will specifically describe the solid electrolyte membrane and the solid-state battery having the solid electrolyte membrane in the present application in detail with reference to specific embodiments.

[0054] Please refer to Figures 1 to 5 , the embodiment of the present application provides a solid-state battery, which includes a positive electrode 14, a negative electrode 13 and a solid electrolyte membrane 10 arranged oppositely. Among them, the solid electrolyte membrane 10 is arranged 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 in sequence.

[0055] Exemplarily, the solid-state battery is a solid-state battery with a soft-pack aluminum plastic film structure. Of course, the outer shell of the solid-state battery can also be an aluminum shell, a plastic shell, a steel shell, etc., which are not limited herein. Without special instructions, the solid-state batteries in the following text are all solid-state batteries with a soft-pack aluminum plastic film structure.

[0056] In some embodiments of the present application, a positive electrode active layer is provided on the positive electrode sheet 14. Exemplarily, the positive electrode sheet 14 includes a positive electrode current collector and a positive electrode active layer provided 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 other than the positive electrode tab 141.

[0057] In some embodiments of the present application, a negative electrode active layer is provided on the negative electrode sheet 13. Exemplarily, the negative electrode sheet 13 includes a negative electrode current collector and a negative electrode active layer provided 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 other than the negative electrode tab 131.

[0058] In some embodiments of the present application, the solid electrolyte membrane 10 includes a body 11, and the body 11 includes a first surface and a second surface which are oppositely arranged. The first surface faces the positive electrode active layer (i.e., faces the positive electrode sheet 14), and the second surface faces the negative electrode active layer (i.e., faces the negative electrode sheet 13).

[0059] In some embodiments of the present application, please refer to Figure 5 , the first surface includes a first central region 111 and a first edge region. The first central region 111 is disposed opposite to the positive electrode active layer. The first edge region is in a closed annular shape, and the first central region 111 is located within the first edge region. The first central region 111 is also the region on the first surface covered by the positive electrode active layer, that is, the orthographic projection region of the positive electrode active layer on the solid electrolyte membrane 10. The first edge region is the region 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 generally in a planar layered structure. To avoid 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 (that is, the portion of the positive electrode sheet 14 excluding the positive electrode ear 141) is a 10mm*10mm square, that is, the positive electrode active layer is a 10mm*10mm square, the solid electrolyte membrane 10 is a 12mm*12mm square, and the positive electrode sheet 14 is stacked in the middle position on the solid electrolyte membrane 10 (that is, the orthographic projection of the center of the square area in the positive electrode sheet 14 coincides with the center of the solid electrolyte membrane 10, and the outer contour line of the square area 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 area 111 coincides with the center of the solid electrolyte membrane 10, the first central area 111 is a 10mm*10mm square, and the first edge area is the area between a square with a side length of 12mm*12mm (that is, the area enclosed by the outer contour line of the solid electrolyte membrane 10) and a 10mm*10mm square therein (that is, the area covered by the positive electrode active layer on the first surface).

[0061] In some embodiments of this application, please refer to Figure 4 , the second surface includes a second central region 113 and a second edge region, the second central region 113 is arranged opposite to the negative electrode active layer, the second edge region is a closed ring, and the second central region 113 is located in the second edge region. Similarly, the second central region 113 is also the region covered by the negative electrode active layer on the second surface, that is, the positive projection region of the negative electrode active layer on the solid electrolyte membrane 10. The second edge region is the region on the second surface excluding the second central region 113.

[0062] In some embodiments of this application, please refer to Figure 5 , the protrusion 12 (i.e., the first protrusion 121) is located in the first edge region and extends along the first edge region. Exemplarily, the protrusion 12 (i.e., the first protrusion 121) covers the first edge region, the first edge region is in the shape of the Chinese character "回", and the protrusion 12 (i.e., the first protrusion 121) is also in the shape of the Chinese character "回". In this way, it is beneficial to improve the effect of the protrusion 12 in blocking 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, and 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 the embodiment of the present application, a protrusion 12 (i.e., a first protrusion 121) is provided in the first edge region of the first surface, and the protrusion 12 (i.e., the first protrusion 121) is annular, so that when the solid electrolyte membrane 10 in the present application is used in a solid-state battery, the protrusion 12 can form a certain gap in the solid-state battery, and the gap can provide a space for the negative electrode sheet 13 whose thickness increases during use, which is conducive to reducing the expansion rate of the solid-state battery. In addition, the protrusion 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 this application, please refer to Figure 4 and Figure 5 , Figure 4 and Figure 5 The difference is that Figure 4 The solid electrolyte 10 in the embodiment has only the second surface provided with the second convex layer 122, while Figure 5 The solid electrolyte 10 in the embodiment is provided with a first convex layer 121 on the first surface and a first convex layer 122 on the second surface. The protrusion 12 (i.e., the second convex layer 122) is located in the second edge region and extends along the second edge region. Exemplarily, the protrusion 12 covers the second edge region, the second edge region is in the shape of the Chinese character "回", and the protrusion 12 is also in the shape of the Chinese character "回". In this way, it is beneficial to improve the effect of the protrusion 12 in blocking 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, and 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 the embodiment of the present application, a protrusion 12 (i.e., a second protrusion 122) is provided in the second edge region of the second surface, and the protrusion 12 is annular, so that when the solid electrolyte membrane 10 in the present application is used in a solid-state battery, the protrusion 12 can form a certain gap in the solid-state battery, and the gap can provide a space for the negative electrode sheet 13 whose thickness increases during use, which is conducive to reducing the expansion rate of the solid-state battery. In addition, the protrusion 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, a solid electrolyte membrane 10 is provided in the present application. By providing a raised portion 12 in the first edge region of the first surface and / or the second edge region of the second surface, and the raised portion 12 is annular, 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 or the second central region 113 to the first edge region or the second edge region, improving or avoiding the problem of the decline in the electrical performance of the solid-state battery caused by 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, thereby improving the electrical performance of the solid-state battery.

[0067] In some embodiments of the present application, please refer to Figure 5 , the raised portion 12 includes a first raised layer 121 and a second raised layer 122. Both the first raised layer 121 and the second raised layer 122 are annularly arranged. The first raised layer 121 is located in the first edge region and extends along the first edge region; the second raised layer 122 is located in the second edge region and extends along the second edge region.

[0068] In this embodiment, by providing the first raised layer 121 on the first surface and the second raised layer 122 on the second surface, it is beneficial to increase the number of gaps in the solid-state battery, thereby increasing the volume of the accommodation space, which is beneficial to further reducing the expansion rate of the solid-state battery. In addition, by providing the raised portion 12 on both surfaces of the solid electrolyte membrane 10, it is beneficial to further 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, thereby further improving the electrical performance of the solid-state battery.

[0069] In some embodiments of the present application, the thickness of the first raised layer 121 is 4 μm to 130 μm. It should be noted that the thickness of the first raised layer 121 refers to the dimension of the first raised layer 121 in a plane perpendicular to the plane where the body 11 is located. It can be understood that if the thickness of the first raised layer 121 is too small, for example, the thickness of the first raised layer 121 is less than 4 μm, the volume of the accommodation space formed by it in the battery is small, and the effect of improving or avoiding 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 is not obvious. If the thickness of the first raised layer 121 is too large, for example, the thickness of the first raised layer 121 is greater than 130 μm, it is easy to cause the solid-state battery to have a large volume.

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

[0071] It should be noted that the thickness of the first convex layer 121 is also related to the cathode active material. In some embodiments of the present application, the cathode sheet 14 is selected from a lithium iron phosphate cathode sheet 14 and a lithium cobalt oxide cathode sheet 14. Specifically, if the cathode sheet 14 is a lithium iron phosphate cathode sheet 14 (i.e., the active main material of the cathode sheet 14 is lithium iron phosphate), the thickness of the convex portion 12 (i.e., the first convex layer 121) located on the first edge region is 4μm to 110μm. If the cathode sheet 14 is a lithium cobalt oxide cathode sheet 14 (i.e., the active main material of the cathode sheet 14 is lithium cobalt oxide), the thickness of the first convex layer 121 of the convex portion 12 located on the first edge region is 4μm to 130μm.

[0072] In some embodiments of the present application, the thickness of the second convex layer 122 is 4μm to 130μm. It should be noted that the thickness of the second convex layer 122 refers to the dimension of the second convex layer 122 in a plane perpendicular to the plane where the body 11 is located. It can be understood that if the thickness of the second convex layer 122 is too small, for example, the thickness of the second convex layer 122 is less than 4μm, the volume of the accommodation space formed by it in the battery is small, and the effect of improving or avoiding 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 is not obvious. If the thickness of the second convex layer 122 is too large, for example, the thickness of the second convex layer 122 is greater than 130μm, it is likely to cause the solid-state battery to have a large volume.

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

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

[0075] In some embodiments of the present application, the body 11 and the convex portion 12 are of an integral structure. In this way, it is beneficial to improve the connection force between the convex portion 12 and the body 11.

[0076] In some embodiments of the present application, the convex portion 12 can be formed by processes such as coating, bonding, deposition, 3D printing, and chemical etching. Exemplarily, the convex portion 12 can be integrally formed on the body 11 by processes such as coating, bonding, deposition, 3D printing, and chemical etching. In this way, it is beneficial to improve the connection force between the convex portion 12 and the body 11.

[0077] In some embodiments of the present application, the convex portion 12 located on the first edge region is a closed ring. In this way, it is beneficial to improve the effect of the convex portion 12 in blocking 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.

[0078] In some embodiments of the present application, the convex portion 12 located on the second edge region is a closed ring. In this way, it is beneficial to improve the effect of the convex portion 12 in blocking 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.

[0079] In some embodiments of the present application, in order to avoid mutual corrosion between the solid electrolyte membrane 10 and the positive and negative electrode sheets 13 and improve the stability of the solid-state battery, the material for preparing the convex portion 12 does not react with the materials for preparing the body 11, the positive electrode sheet 14, and the negative electrode sheet 13. Exemplarily, the material for preparing the convex portion 12 is selected from one of ceramics, polyimide, and polypropylene.

[0080] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not described in detail in a certain embodiment, reference may be made to the detailed descriptions of other embodiments above, and they will not be repeated here.

[0081] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0082] Meanwhile, this application uses specific terms to describe the embodiments of this application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0083] Similarly, it should be noted that, in order to simplify the expression of this application disclosure and thus help the understanding of one or more invention embodiments, in the previous description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than those mentioned in the claims. In fact, the features of the embodiments are fewer than all the features of the single embodiments disclosed above.

[0084] In some embodiments, numbers describing the components and attribute quantities are used. It should be understood that such numbers used for the description of embodiments are, in some examples, modified by the modifiers "about", "approximately", or "substantially". Unless otherwise stated, "about", "approximately", or "substantially" indicate that the numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values can change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used to confirm the breadth of the scope in some embodiments of this application are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0085] The above has introduced the embodiments of the present application in detail. Specific examples are used herein to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A solid electrolyte membrane for a solid-state battery, the solid-state battery comprising a positive electrode sheet and a negative electrode sheet arranged opposite to each other, the positive electrode sheet is provided with a positive electrode active layer, the negative electrode sheet is provided with a negative electrode active layer, characterized in that: The solid electrolyte membrane comprises a body and a protrusion; the protrusion is annular; The body includes a first surface and a second surface that are oppositely arranged, the first surface faces the positive electrode active layer, and the second surface faces the negative electrode active layer; the first surface includes a first central region and a first edge region, the first central region is arranged opposite to the positive electrode active layer; the first edge region is in a closed ring shape, and the first central region is located in the first edge region; the second surface includes a second central region and a second edge region, the second central region is arranged opposite to the negative electrode active layer, the second edge region is in a closed ring shape, and the second central region is located in the second edge region; 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.

2. The solid electrolyte membrane according to claim 1, characterized in that The raised portion includes a first raised layer and a second raised layer, both of which are arranged in a ring shape, the first raised layer is located in the first edge area and extends along the first edge area; the second raised layer is located in the second edge area and extends along the second edge area.

3. The solid electrolyte membrane according to claim 2, characterized in that The thickness of the first convex layer is 4 μm to 130 μm; and / or The second convex layer has a thickness of 4 μm to 130 μm.

4. The solid electrolyte membrane according to claim 1, characterized in that The main body and the raised portion are an integral structure; and / or The protrusion located on the first edge area is a closed ring; and / or The protrusion located on the second edge area is a closed ring; and / or The material for preparing the protrusion is selected from one of ceramics, polyimide and polypropylene.

5. A solid-state battery, characterized in that: The solid-state battery comprises a positive electrode sheet, a negative electrode sheet and the solid electrolyte membrane according to any one of claims 1 to 4, wherein the positive electrode sheet, the solid electrolyte and the negative electrode sheet are stacked in sequence.

6. The solid-state battery according to claim 5, characterized in that: The positive electrode sheet is selected from one of a lithium iron phosphate positive electrode sheet and a lithium cobalt oxide positive electrode sheet.

7. The solid-state battery according to claim 6, characterized in that The raised portion includes a first raised layer located on the first edge region; If the positive electrode sheet is a lithium iron phosphate positive electrode sheet, the thickness of the first convex layer is 4 μm to 110 μm; or If the positive electrode sheet is a lithium cobalt oxide positive electrode sheet, the thickness of the first protrusion layer is 4 μm to 130 μm.

8. The solid-state battery according to claim 5, characterized in that The negative electrode sheet is selected from one of a graphite negative electrode sheet, a silicon-carbon negative electrode sheet and a lithium metal negative electrode sheet.

9. The solid-state battery according to claim 8, characterized in that The raised portion includes a second raised layer located on the second edge region; If the negative electrode sheet is a graphite negative electrode sheet, the thickness of the second protrusion layer is 4 μm to 90 μm; or If the negative electrode sheet is a silicon-carbon negative electrode sheet, the thickness of the second convex layer is 4 μm to 130 μm. μm ;or If the negative electrode sheet is a lithium metal negative electrode sheet, the thickness of the second protrusion layer is 4 μm to 130 μm. μm .

10. The solid-state battery according to claim 5, characterized in that: The solid-state battery is a soft-pack battery.

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