Negative plate and solid-state battery

Abstract

The utility model provides a negative plate and a solid-state battery with the negative plate, and relates to the technical field of batteries. According to the negative electrode plate provided by the invention, the annular modification layer is arranged in the second region of the negative electrode body, so that when the negative electrode plate is used for the solid-state battery, the modification layer can form a certain gap in the solid-state battery, and the expansion rate of the solid-state battery can be reduced. In addition, the modification layer can prevent lithium ions from diffusing from the first region to the second region, so that the service life of the solid-state battery is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a negative electrode sheet and a solid-state battery having the negative electrode sheet. 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 means such as electric bicycles, electric motorcycles, and electric vehicles, as well as 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. The solid electrolyte can eliminate problems such as flammability, explosiveness, and leakage caused by the liquid electrolyte, and is the preferred electrolyte for the next-generation batteries. Compared with the liquid electrolyte, 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.

[0004] However, the solid-state battery also has the problem of a large expansion rate. Taking the solid-state battery with a lithium metal as the 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 the lithium metal battery is huge (up to 2000 kgf for large battery cells), and the free expansion rate of the battery cell can reach 30% without external force restraint; at the same time, the battery cell has the problem that the electrical performance drops too fast, resulting in an unsatisfactory service life. Summary of the Utility Model

[0005] The present 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, the present application provides a negative electrode sheet for a solid-state battery. The solid-state battery further includes a positive electrode sheet provided with a positive electrode active layer. The negative electrode sheet includes a negative electrode body and a negative electrode modification layer.

[0007] The negative electrode body has a first region disposed opposite to the positive electrode active layer, and a second region located outside the first region. The second region is a closed ring shape, and the first region is located within the second region.

[0008] The negative electrode modification layer is located on the second region, and the negative electrode modification layer is in a ring shape.

[0009] In a possible implementation manner of the present application, the negative electrode modification layer is in a closed annular shape; and / or the negative electrode modification layer covers the second region.

[0010] In a possible implementation manner of the present application, the thickness of the negative electrode modification layer is 4 μm to 130 μm.

[0011] In a possible implementation manner of the present application, the negative electrode body and the negative electrode modification layer are of an integral structure.

[0012] In a possible implementation manner of the present application, the negative electrode body is a metal foil, and the material for preparing the metal foil is selected from one or more of lithium, copper, and silver.

[0013] In a possible implementation manner of the present application, the material for preparing the negative electrode body includes metallic lithium, and the material for preparing the negative electrode modification layer does not react with lithium metal; and / or

[0014] The material for preparing the negative electrode body includes a metallic material, and the material for preparing the negative electrode modification layer is selected from one of ceramics, polyimide, and polypropylene.

[0015] In a second aspect of the present application, a solid-state battery is provided. The solid-state battery includes a positive electrode sheet, a solid electrolyte membrane, and the negative electrode sheet described above, and the positive electrode sheet, the solid electrolyte, and the negative electrode sheet are stacked in sequence.

[0016] 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.

[0017] In a possible implementation manner of the present application, if the positive electrode sheet is a lithium iron phosphate positive electrode sheet, the thickness of the negative electrode modification layer is 4 μm to 110 μm; or

[0018] If the positive electrode sheet is a lithium cobaltate positive electrode sheet, the thickness of the negative electrode modification layer is 4 μm to 130 μm.

[0019] In a possible implementation manner of the present application, the solid-state battery is a soft-pack battery.

[0020] In the present application, a negative electrode sheet is provided. By providing an annular modification layer in the second region of the negative electrode body, when the negative electrode sheet in the present application is used in a solid-state battery, the modification layer can form a certain gap in the solid-state battery. For example, this gap can provide a accommodation space for components that deform during use (such as a negative electrode sheet with an increased thickness, a deformed negative electrode sheet, a deformed solid electrolyte membrane, etc.), which is beneficial to reducing the expansion rate of the solid-state battery.

[0021] In addition, the modification layer can block the diffusion of lithium ions from the first region to the second region, thereby improving the service life of the solid-state battery. Brief Description of the Drawings

[0022] 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.

[0023] Figure 1 It is an exploded structural schematic diagram of a positive electrode sheet, a solid electrolyte membrane, and a negative electrode sheet in a solid-state battery provided by an embodiment of the present application;

[0024] Figure 2 It is a schematic diagram of the laminated structure of the positive electrode sheet and the negative electrode body;

[0025] Figure 3 It is a schematic diagram of the structure of the negative electrode sheet provided by an embodiment of the present application.

[0026] Reference Numerals in the Drawings:

[0027] 10. Negative electrode sheet; 11. Negative electrode body; 111. First region; 112. Second region; 12. Negative electrode modification layer; 13. Negative electrode tab; 20. Solid electrolyte membrane; 30. Positive electrode sheet; 31. Positive electrode tab. Detailed Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are 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 therefore should not be construed as a limitation to the present invention.

[0030] In addition, 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 quantity of the indicated technical features. Thus, 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, "a plurality of" means two or more unless otherwise specifically defined.

[0031] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or instance". Any embodiment described as "exemplary" in this application is not necessarily to be construed as 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 present invention. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without these specific details. In other instances, well-known structures and processes are not described 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.

[0032] A traditional liquid lithium-ion battery is composed of a positive electrode sheet, a separator, a negative electrode sheet, an electrolyte, and a casing.

[0033] It should be noted that after the thermal runaway of the battery, the electrolyte has safety hazards such as being prone to catching fire and explosion. The solid electrolyte can eliminate problems such as flammability, easy explosion, and leakage caused by the liquid electrolyte, and is the preferred electrolyte for next-generation batteries. Compared with the liquid electrolyte, the advantages of the solid electrolyte include higher safety, higher density, better stability, limited generation of lithium dendrites, and a higher working temperature range. These advantages significantly improve the adaptability and reliability of the solid-state battery.

[0034] However, the solid-state battery also has the problem of a relatively large expansion rate. Taking a lithium-metal-based negative electrode sheet lithium-ion solid-state battery as an example, during the use of the lithium-ion solid-state battery, since lithium ions are deposited on the negative electrode sheet to form lithium metal, the thickness of the negative electrode sheet increases, which will cause the overall thickness of the battery cell to expand during charging. Tests have found that the expansion force of a lithium-metal-based negative electrode sheet lithium-ion solid-state battery 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 solid-state battery also has the problem that the electrical performance deteriorates too quickly, resulting in an unsatisfactory service life.

[0035] In view of the above-mentioned at least one technical problem existing in the existing solid-state battery.

[0036] The embodiment of the present application provides a negative electrode sheet and a solid-state battery having the negative electrode sheet. By providing an annular modification layer in the second region of the negative electrode body, when the negative electrode sheet in the present application is used in a solid-state battery, the modification layer can form a certain gap in the solid-state battery. For example, this gap can provide a accommodation space for components that deform during use (such as a negative electrode sheet with increased thickness, a deformed negative electrode sheet, a deformed solid electrolyte membrane, etc.), which is beneficial to reducing the expansion rate of the solid-state battery.

[0037] In addition, the inventors have found through research that during storage or use of a solid-state battery cell or a solid-state battery, lithium ions will diffuse from the negative electrode sheet to the periphery opposite to the outer contour of the positive electrode sheet, resulting in self-discharge of the solid-state battery cell or the solid-state battery or a decline in the comprehensive performance during use. In the present application, by providing a modification layer, the modification layer can block the diffusion of lithium ions from the first region to the second region in the periphery, thereby improving the service life of the solid-state battery.

[0038] The following will separately describe in detail the negative electrode sheet and the solid-state battery having the negative electrode sheet in the present application with specific embodiments.

[0039] The embodiment of the present application provides a solid-state battery, which includes one or more battery cells. Exemplarily, the solid-state battery includes a battery cell, a housing, a connector, etc. It can be understood that the battery cell is the core component of the battery, and its main function is to store and release electrical energy, which is the basic unit of the battery.

[0040] It should be noted that the shape of the solid-state battery is not limited. Exemplarily, the shape of the solid-state battery can be a cuboid, a cube, a cylinder, an irregular polygon, etc.

[0041] The solid-state battery in the present application includes but is not limited to a soft-pack solid-state battery. Exemplarily, the solid-state battery is a solid-state battery with a soft-pack aluminum plastic film structure. Of course, the housing of the solid-state battery can also be an aluminum shell, a plastic shell, a steel shell, etc., which is not limited herein. Unless otherwise specified, the solid-state batteries in the following text are all solid-state batteries with a soft-pack aluminum plastic film structure.

[0042] In the present application, please refer to Figures 1 to 3 , the solid-state battery cell includes a positive electrode sheet 30, a negative electrode sheet 10, and a solid electrolyte membrane 20. That is, the solid-state battery includes a positive electrode sheet 30, a negative electrode sheet 10, and a solid electrolyte membrane 20. Among them, the solid electrolyte membrane 20 is disposed between the positive electrode sheet 30 and the negative electrode sheet 10. Exemplarily, the solid-state battery cell includes the positive electrode sheet 30, the solid electrolyte membrane 20, and the negative electrode sheet 10 stacked in sequence.

[0043] In some embodiments of the present application, a positive electrode active layer (not shown in the figure) is provided on the positive electrode sheet 30. Exemplarily, the positive electrode sheet 30 includes a positive electrode current collector (not shown in the figure) 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 31.

[0044] In some embodiments of the present application, the negative electrode sheet 10 includes a negative electrode body 11 and a negative electrode modification layer 12. The negative electrode body has a first region 111 disposed opposite to the positive electrode active layer (i.e., the positive electrode sheet 30), and a second region 112 located outside the first region 111. The second region 112 is in a closed annular shape, and the first region 111 is located within the second region 112.

[0045] Exemplarily, the negative electrode body 11 is a metal foil. Further, the material for preparing the metal foil is selected from one or more of lithium, copper, and silver. For example, the negative electrode body 11 is a lithium metal sheet negative electrode. Another example is that the negative electrode body 11 is a copper metal sheet negative electrode. Another example is that the negative electrode body 11 is a silver metal sheet negative electrode. Unless otherwise specified below, the lithium metal sheet negative electrode (also referred to as the lithium metal negative electrode or lithium negative electrode) is taken as an example for description.

[0046] In the embodiments of the present application, the positive electrode sheet 30, the negative electrode sheet 10, and the solid electrolyte membrane 10 are all generally in a planar layer structure. To improve the performance of the battery, in a soft-pack battery, the area of the solid electrolyte membrane 20 is slightly larger than the area of the negative electrode sheet 10, and the area of the negative electrode sheet 10 is slightly larger than the area of the positive electrode sheet 30. Hereinafter, the positive electrode sheet 30 and the negative electrode sheet 10 are both square as an example for description.

[0047] Exemplarily, the positive electrode sheet 30 (i.e., the part of the positive electrode sheet 30 other than the positive electrode tab 31) is a square with a size of 10 mm × 10 mm, that is, the positive electrode active layer is a square with a size of 10 mm × 10 mm. The negative electrode body 11 is a square with a size of 12 mm × 12 mm. The positive electrode sheet 30 is stacked on the negative electrode body 11 and is located at a position close to the middle of the negative electrode body 11 (for example, the orthographic projection of the center of the square area in the positive electrode sheet 30 coincides with the center of the square area in the negative electrode body 11, and the outer contour line of the square area in the positive electrode sheet 30 is parallel to the outer contour line of the negative electrode body 11). Then, when the positive electrode sheet 30 and the negative electrode body 11 are stacked, the positive electrode active layer will cover a 10 mm × 10 mm square area located in the middle of the negative electrode body 11, that is, the positive electrode active layer will cover the first area 111 on the negative electrode body 11. Correspondingly, the part of the surface of the negative electrode body 11 facing the positive electrode active layer that is not covered by the positive electrode active layer is the second area 112, that is, the area between the outer contour line of the negative electrode body 11 (for example, the outer contour line of a 12 mm × 12 mm square) and the outer contour line of a 10 mm × 10 mm square inside it (that is, the outer contour line of the area on the negative electrode sheet covered by the positive electrode active layer) is the second area 112.

[0048] Also exemplarily, please refer to Figure 2 and Figure 3 , both the positive electrode sheet 30 and the negative electrode sheet 10 are generally rectangular. The first area 111 is the area covered by the orthographic projection of the positive electrode active layer on the negative electrode sheet 10 (or the negative electrode body 11) when the positive electrode sheet 30 and the negative electrode sheet 10 (or the negative electrode body 11) are stacked (with the positive electrode active layer facing the negative electrode sheet 10), or the area on the negative electrode body 11 covered or blocked by the positive electrode active layer (i.e., the positive electrode sheet 30). The second area 112 is the area on the negative electrode body 11 that is not covered by the positive electrode active layer (i.e., the positive electrode sheet 30) when the positive electrode sheet 30 and the negative electrode body 11 are stacked (with the positive electrode active layer facing the negative electrode sheet).

[0049] In the embodiment of the present application, by providing an annular negative electrode modification layer 12 in the second area 112 of the negative electrode body 11, when the negative electrode sheet 10 in the present application is used in a solid-state battery, the negative electrode modification layer 12 can form a certain gap in the solid-state battery. For example, this gap can provide a accommodation space for components that deform during use (such as a negative electrode sheet with an increased thickness, a deformed negative electrode sheet, a deformed solid electrolyte membrane, etc.), which is beneficial to reducing the expansion rate of the solid-state battery. Using a solid-state battery with this structure, the expansion rate of the battery within the life cycle can be within 10%.

[0050] In addition, the negative electrode modification layer 12 can block the diffusion of lithium ions from the first area 111 to the second area 112 at the edge, avoiding the short-circuit risk caused by the solid-state battery, and greatly improving the safety and the overall electrical performance of the solid-state battery.

[0051] In some embodiments of the present application, the thickness of the negative electrode modification layer 12 is 4 μm to 130 μm. It should be noted that the thickness of the negative electrode modification layer 12 refers to the dimension of the negative electrode modification layer 12 in a plane perpendicular to the plane where the negative electrode body 11 is located.

[0052] It can be understood that if the thickness of the negative electrode modification layer 12 is too small, for example, the thickness of the negative electrode modification layer 12 is less than 4 μm, the volume of the accommodation space formed by it in the solid-state battery is small, and the effect of improving or avoiding the diffusion of lithium ions from the first region 111 at the central position to the second region 112 at the edge is not obvious. If the thickness of the negative electrode modification layer 12 is too large, for example, the thickness of the negative electrode modification layer 12 is greater than 130 μm, it is likely to cause the solid-state battery to have a large volume.

[0053] Exemplarily, the thickness of the negative electrode modification layer 12 is 4 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm.

[0054] It should be noted that the thickness of the negative electrode modification layer 12 is also related to the positive electrode active material. In some embodiments of the present application, the positive electrode sheet 30 is a lithium iron phosphate positive electrode sheet, that is, the active material of the positive electrode active layer in the positive electrode sheet 30 is mainly lithium iron phosphate. Exemplarily, if the positive electrode sheet 30 is a lithium iron phosphate positive electrode sheet, the thickness of the negative electrode modification layer 12 located on the second region 112 is 4 μm to 110 μm.

[0055] For another example, the positive electrode sheet 30 is a lithium cobalt oxide positive electrode sheet, that is, the active material of the positive electrode active layer in the positive electrode sheet 30 is mainly lithium cobalt oxide. Exemplarily, if the positive electrode sheet 30 is a lithium cobalt oxide positive electrode sheet, the thickness of the negative electrode modification layer 12 located on the second region 112 is 4 μm to 130 μm.

[0056] In some embodiments of the present application, the negative electrode body 11 and the negative electrode modification layer 12 are an integral structure. It can be understood that the integral structure of the negative electrode body 11 and the negative electrode modification layer 12 is beneficial to improving the connection force between the negative electrode modification layer 12 and the negative electrode body 11 and increasing the overall strength of the negative electrode body 11 and the negative electrode modification layer 12.

[0057] In some embodiments of the present application, the negative electrode modification layer 12 can be formed by processes such as coating, bonding, deposition, 3D printing, chemical etching, etc.

[0058] In some embodiments of the present application, the negative electrode modification layer 12 located on the second region 112 is a closed ring, that is, the negative electrode modification layer 12 is a continuous ring.

[0059] It is understandable that the negative electrode modification layer 12 is a closed ring, which is beneficial to improving the effect of the negative electrode modification layer 12 in blocking the diffusion of lithium ions from the first region 111 to the second region 112.

[0060] Exemplarily, the negative electrode modification layer 12 is a square ring.

[0061] In some embodiments of the present application, the negative electrode modification layer 12 covers the second region. In this way, the width of the negative electrode modification layer 12 (i.e., the dimension of the negative electrode modification layer 12 along the connection direction of the second region and the first region) can be increased, and the connection area between the negative electrode modification layer 12 and the negative electrode body 11 can be increased, which is beneficial to improving the connection force between the negative electrode modification layer 12 and the negative electrode body 11, and further improving the effect of the negative electrode modification layer 12 in blocking the diffusion of lithium ions from the first region 111 to the edge second region 112, thereby improving the service life of the solid-state battery.

[0062] In some embodiments of the present application, in order to avoid mutual corrosion between the negative electrode body 11 and the negative electrode modification layer 12 and improve the stability of the solid-state battery, the material for preparing the negative electrode modification layer 12 does not react with the material for preparing the negative electrode body 11.

[0063] Exemplarily, the material for preparing the negative electrode body includes a metal material. Exemplarily, the metal material is selected from one or more of lithium, copper, and silver. Specifically, the material for preparing the negative electrode body 11 includes metallic lithium, and the material for preparing the negative electrode modification layer 12 does not react with lithium metal. For example, the material for preparing the negative electrode modification layer 12 is selected from one of ceramics (such as alumina), polyimide, and polypropylene.

[0064] Furthermore, the material for preparing the negative electrode modification layer 12 also does not react with the material for preparing the solid electrolyte membrane 20.

[0065] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the detailed descriptions of other embodiments above, and details will not be repeated here.

[0066] 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 the present application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to the present application. Such modifications, improvements, and corrections are proposed in the present application, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0067] In the meantime, this application uses specific terms to describe the embodiments of this application. For example, "an embodiment", "one 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.

[0068] Similarly, it should be noted that, in order to simplify the description of this application's disclosure and thus help with the understanding of one or more embodiments of the invention, in the previous description of the embodiments of this application, sometimes multiple features are grouped into one embodiment, drawing, or description thereof. However, this method of disclosure does not mean that the features required by the subject matter 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 individual embodiments disclosed above.

[0069] In some embodiments, numbers are used to describe the components and the quantity of attributes. It should be understood that such numbers used for the description of embodiments are, in some examples, modified by the modifiers "about", "approximate", or "substantially". Unless otherwise stated, "about", "approximate", 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 in some embodiments of this application to confirm the breadth of their scope are approximate values, in specific embodiments, such numerical settings are made as precise as possible within the feasible range.

[0070] The embodiments of this application have been introduced in detail above. 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, based on 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 negative electrode sheet for a solid-state battery, the solid-state battery also comprising a positive electrode sheet, the positive electrode sheet being provided with a positive electrode active layer, characterized in that: The negative electrode sheet comprises a negative electrode body and a negative electrode modification layer; The negative electrode body comprises a first region arranged opposite to the positive electrode active layer, and a second region located outside the first region, the second region is in a closed ring shape, and the first region is located within the second region; The negative electrode modification layer is located on the second region, and the negative electrode modification layer is ring-shaped.

2. The negative electrode sheet according to claim 1, characterized in that: The negative electrode modification layer is in a closed ring shape; and / or The negative electrode modification layer covers the second region.

3. The negative electrode sheet according to claim 1, characterized in that: The thickness of the negative electrode modification layer is 4 μm to 130 μm.

4. The negative electrode sheet according to claim 1, characterized in that: The negative electrode body and the negative electrode modification layer are an integrated structure.

5. The negative electrode sheet according to claim 1, characterized in that: The negative electrode body is a metal foil, and the material for preparing the metal foil is selected from one or more of lithium, copper, and silver.

6. The negative electrode sheet according to claim 1, characterized in that: The material used to prepare the negative electrode body includes metallic lithium, and the material used to prepare the negative electrode modification layer does not react with lithium metal; and / or The material used to prepare the negative electrode body includes a metal material, and the material used to prepare the negative electrode modification layer is selected from one of ceramics, polyimide, and polypropylene.

7. A solid-state battery, characterized in that: The solid-state battery comprises a positive electrode sheet, a solid electrolyte membrane and the negative electrode sheet according to any one of claims 1 to 6, wherein the positive electrode sheet, the solid electrolyte and the negative electrode sheet are stacked in sequence.

8. The solid-state battery according to claim 7, 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.

9. The solid-state battery according to claim 8, characterized in that If the positive electrode sheet is a lithium iron phosphate positive electrode sheet, the thickness of the negative electrode modification 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 negative electrode modification layer is 4 μm to 130 μm.

10. The solid-state battery according to claim 7, characterized in that: The solid-state battery is a soft-pack battery.

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