Lithium ion battery, shell of lithium ion battery and electronic product

Abstract

The utility model relates to the field of lithium ion batteries, and discloses a lithium ion battery, a shell of the lithium ion battery and an electronic product. The shell comprises a metal shell body and a cover plate assembly, the open end of the metal shell body serves as the top, the shell bottom of the metal shell body is a curved surface, a step lower than the side wall is arranged at the position, at the open end of the metal shell body, of the inner wall of the side wall, the step surrounds the side wall to be in a closed ring shape, and the heights from all positions of the step to the shell bottom are the same. Comprising a first metal cover plate, a second metal cover plate and an insulating layer, the outer edge of the first metal cover plate is the outer edge of the cover plate assembly, the first metal cover plate and the insulating layer are respectively provided with a through hole, the second metal cover plate seals the two through holes, and the insulating layer is combined between the first metal cover plate and the second metal cover plate in a sealing mode. The top face and the bottom face of the second metal cover plate are exposed out of the top face and the bottom face of the cover plate assembly respectively, the cover plate assembly is limited between the side walls of the metal shell, the bottom face of the outer edge of the first metal cover plate makes face-to-face contact with the step, metal of the contact face is fused, sealed and combined, and the cover plate assembly seals the opening of the metal shell. By adopting the technical scheme, the capacity of the lithium ion battery can be improved in a limited space.

Description

Technical Field

[0001] The utility model relates to the field of battery manufacturing, in particular to a lithium ion battery and a shell thereof and an electronic product. Background Art

[0002] As the application of smart wearable products becomes more and more widespread, people's demand for small-sized button-type secondary rechargeable batteries (lithium-ion batteries for short) is also increasing.

[0003] Lithium-ion batteries are currently the most widely used type, and are increasingly used in smart wearable products, medical products, etc.

[0004] Hearing aids, especially cochlear hearing aids, have higher and higher functional demands from end users. Adding functions such as Bluetooth to the original ones has increased the power consumption of hearing aids and the demand for battery capacity has become higher and higher. Summary of the invention

[0005] One of the purposes of the embodiments of the present utility model is to provide a lithium-ion battery and its housing and an electronic product. The adoption of this technical solution is conducive to increasing the capacity of the lithium-ion battery in a limited space.

[0006] In a first aspect, the present embodiment provides a housing suitable for a lithium-ion battery, comprising:

[0007] A metal shell, wherein the opening end of the metal shell is the top, the shell bottom of the metal shell is a curved surface, and at the opening end of the metal shell, a step lower than the side wall is provided on the inner wall of the side wall, the step surrounds the side wall in a closed ring, and the height from each part of the step to the shell bottom is the same,

[0008] A cover plate assembly comprises a first metal cover plate, a second metal cover plate and an insulating layer, wherein the outer edge of the first metal cover plate is the outer edge of the cover plate assembly, a through hole is respectively provided on the first metal cover plate and the insulating layer, the second metal cover plate seals the two through holes, the insulating layer is sealed and combined between the first metal cover plate and the second metal cover plate, and the top surface and the bottom surface of the second metal cover plate are respectively exposed to the top surface and the bottom surface of the cover plate assembly through the two through holes,

[0009] The cover plate assembly is located between the side walls of the metal shell, the bottom surface of the outer edge of the first metal cover plate is in face-to-face contact with the step, the metals of the contact surfaces are melted and sealed, and the cover plate assembly seals the opening of the metal shell.

[0010] Optionally, the cover plate assembly is a curved surface parallel to the shell bottom.

[0011] Optionally, it also includes a metal sheet with an arc-shaped surface,

[0012] A penetrating injection hole is provided on the shell bottom, and the metal sheet covers the shell bottom in face-to-face contact. A sealing track is formed on the metal sheet, and the sealing track completely surrounds the injection hole and is at a predetermined distance from the injection hole. In the sealing track area, the metal of the contact surface between the metal sheet and the shell bottom is melted and sealed.

[0013] Optionally, on the top surface of the cover plate assembly, the top surfaces of the first metal cover plate and the second metal cover plate are flush with each other, and the outer periphery of the second metal cover plate exposed on the top surface of the cover plate assembly has a predetermined distance from the first metal cover plate.

[0014] Optionally, the second metal cover plate is sealed and bonded to the bottom surface of the first metal cover plate through the insulating layer, and the bottom surface of the second metal cover plate is completely exposed from the bottom surface of the cover plate assembly.

[0015] The area of ​​the second metal cover plate facing the through hole of the insulating layer bulges toward the top, forming a boss on the top surface of the second metal cover plate and a recess opposite to the boss on the bottom surface of the second metal cover plate, and the top of the boss is exposed to the top surface of the cover plate assembly through the through hole of the insulating layer.

[0016] Optionally, the edges of the opening ends of at least two opposite side walls of the metal shell at the shell bottom and the shell top and the step are parallel arc-shaped, and the outer edge of the cover assembly sealed on the metal shell is arc-shaped.

[0017] In a second aspect, an embodiment of the present invention provides a lithium-ion battery, comprising:

[0018] Any of the above-mentioned housings,

[0019] The lithium-ion battery stack is filled with electrolyte, and the bottom surface of the stack is curved and abuts against the bottom of the shell.

[0020] The two electrodes of the laminated body are respectively connected to the bottom surfaces of the first metal cover plate and the second metal cover plate of the cover plate assembly of the shell.

[0021] Optionally, it also includes a first electrode sheet and a second electrode sheet, one end of which is respectively connected to the top surface of the first metal cover plate and the second metal cover plate, and the other end extends out of the shell for external connection, and an insulating sheet is spaced between the second electrode sheet and the top surface of the first metal cover plate.

[0022] Optionally, the second metal cover plate is sealed and bonded to the bottom surface of the first metal cover plate through the insulating layer, and the bottom surface of the second metal cover plate is completely exposed from the bottom surface of the cover plate assembly.

[0023] The area of ​​the second metal cover plate facing the through hole of the insulating layer protrudes toward the top, forming a boss on the top surface of the second metal cover plate, and the top of the boss is exposed to the top surface of the cover plate assembly through the through hole of the insulating layer. The positive electrode of the stack is welded to the bottom surface of the second metal cover plate, and the negative electrode is connected to the bottom surface of the second metal cover plate or the inner wall of the metal shell.

[0024] In a third aspect, an embodiment of the utility model provides an electronic product, wherein a lithium-ion battery as described above is disposed in a battery chamber of the electronic product, a shell wall of the lithium-ion battery shell is in contact with an inner wall of the battery chamber, and an electrode of the lithium-ion battery is electrically connected to a circuit module of the electronic product.

[0025] As can be seen from the above, relative to the technical solution of sealing the bottom surface of the cover assembly with the end surface of the side wall at the opening end, the technical solution of this embodiment is to set a step lower than the side wall on the inner wall of the side wall of the metal shell. The side wall limits the cover assembly on the step between the side walls, ensuring the contact surface of the cover assembly with the step, which is conducive to improving the accuracy of positioning and sealing and improving work efficiency.

[0026] In particular, after sealing, the cover assembly of the present embodiment is a curved surface. A cover assembly with an area larger than the cross-sectional area of ​​the opening of the metal shell can be used. The side wall of the metal shell is used to position the outer edge of the cover assembly so that the cover assembly is deformed into a curved surface. This solution is further beneficial to the positioning of the cover assembly and the metal shell, improves the reliability of the sealing connection between the cover assembly and the metal shell, and facilitates operation.

[0027] As an illustration of this embodiment, it is preferred but not limited to make the cover assembly sealed at the open end of the metal shell a curved surface parallel to the shell bottom. The height of the cavity in the metal shell is consistent at all locations, which is conducive to increasing the thickness of the laminate and the capacity of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute an improper limitation of the present invention.

[0029] Figure 1 A side structural schematic diagram of a cover plate assembly provided in an embodiment of the utility model;

[0030] Figure 2 for Figure 1 A schematic diagram of the top view of the cover plate shown;

[0031] Figure 3 for Figure 1 A schematic diagram of the structure of the cover plate as viewed from above;

[0032] Figure 4 for Figure 1 A three-dimensional schematic diagram of the exploded structure of the cover plate shown;

[0033] Figure 5 for Figure 4 A schematic diagram of the exploded structure of the cover plate shown;

[0034] Figure 6 A schematic diagram of the three-dimensional structure of the connection of the pole ears on the bottom surface of the cover plate provided by an embodiment of the utility model;

[0035] Figure 7 A schematic diagram of the three-dimensional structure of the connection of the pole ears on the bottom surface of the cover plate provided by an embodiment of the utility model;

[0036] Figure 8 A schematic diagram of the side view structure of the connection of the pole ears on the bottom surface of the cover plate provided by an embodiment of the utility model;

[0037] Fig. 9 A schematic diagram of the three-dimensional structure of a lithium-ion battery provided in an embodiment of the utility model;

[0038] Fig.10 A schematic diagram of the side structure of a lithium-ion battery provided by an embodiment of the utility model;

[0039] Fig.11 A schematic diagram of a top view of a lithium-ion battery provided in an embodiment of the utility model;

[0040] Fig.12 A bottom-up structural schematic diagram of a lithium-ion battery provided in an embodiment of the utility model;

[0041] Fig.13 A schematic diagram of the right side structure of a lithium-ion battery provided in an embodiment of the utility model;

[0042] Fig.14 A schematic diagram of the left side structure of a lithium-ion battery provided in an embodiment of the utility model;

[0043] Fig.15 A schematic diagram of the three-dimensional structure of an external electrode sheet of a lithium-ion battery provided in an embodiment of the utility model.

[0044] 1: metal shell; 11: step; 12: side wall;

[0045] 13: Shell bottom; 2: Cover plate assembly; 21: First metal cover plate;

[0046] 211: first through hole; 22: second metal cover plate; 221: boss; 23: insulating layer; 231: second through hole; 3: tab; 41: first electrode sheet; 42: second electrode sheet; 5: insulating sheet. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The schematic embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0048] Examples of embodiments of the present invention described in detail below are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions.

[0049] The embodiments described below with reference to the drawings attached to this specification are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships 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 limiting the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0052] See also Figure 1-15 .

[0053] This embodiment provides a shell suitable for lithium-ion batteries, which includes: a metal shell 1 and a cover plate assembly 2, wherein one end of the metal shell 1 is open, and the cover plate assembly 2 seals the opening. For the convenience of description, the open end of the metal opening is referred to as the top, the shell bottom 13 is opposite to the open end, and the shell wall surrounding the shell bottom 13 to form the open end is referred to as the side wall 12. A metal cover plate serving as an electrode of the lithium-ion battery is arranged on the cover plate assembly 2.

[0054] The bottom 13 of the metal shell 1 is a curved surface, such as but not limited to convex toward the bottom or convex toward the top, and the shape of the curved surface can be determined according to the shape of the bottom of the adapted battery chamber. The radius of each part of the curved surface can be the same or different.

[0055] A circle of steps 11 is also provided on the inner periphery of the side wall 12 at the open end of the metal shell 1. The steps 11 surround the side wall 12 to form a closed ring. The top surface of the step 11 is at the same height from the shell bottom 13 at all places. The top surface of the step 11 is slightly lower than the top surface of the side wall 12, so that when the cover assembly 2 is sealed on the step 11, the top surface of the cover assembly 2 is basically flush with the side wall 12.

[0056] The cover plate assembly 2 includes a first metal cover plate 21 and a second metal cover plate 22, which are respectively used as two electrode terminals of the lithium-ion battery. The outer edge of the first metal cover plate 21 is the outer edge of the cover plate assembly 2. A first through hole 211 is provided on the first metal cover plate 21, and a second through hole 231 with a larger aperture than the first through hole 211 is provided on the insulating layer 23. When assembled, the first metal cover plate 21, the second metal cover plate 22, and the insulating layer 23 are stacked, the centers of the first through hole 211 and the second through hole 231 are opposite, the second metal cover plate 22 seals the first through hole 211 and the second through hole 231, the insulating layer 23 is sealed and combined between the first metal cover plate 21 and the second metal cover plate 22, and the two surfaces of the insulating layer 23 are respectively sealed and combined with the surfaces of the first metal cover plate 21 and the second metal cover plate 22 that are attached to the surfaces to form a three-layer sealed combination structure.

[0057] The order from large to small in outer diameter and from outside to inside is respectively the first metal cover plate 21, the insulating layer 23, and the second metal cover plate 22, and the second metal cover plate 22 is located at the innermost layer. Through the second through hole 231, the top surface and the bottom surface of the second metal cover plate 22 are exposed to the top surface and the bottom surface of the cover plate assembly 2, respectively, so as to be connected to the outside and to the electrodes of the battery cell in the shell.

[0058] The connection between the cover assembly 2 and the metal shell 1 is specifically that the outer edge of the first metal cover 21 is limited to the inner wall of the side wall 12, and the bottom surface of the outer edge is face-to-face contact with the top surface of the step 11 on the inner wall of the side wall 12 surrounding the metal shell 1, and the metal on the contact surface is melted and sealed into one.

[0059] The housing of this embodiment is applied to lithium-ion batteries, and is particularly suitable for laminated lithium-ion batteries. The following description is made using a laminated lithium-ion battery as the battery cell.

[0060] The laminated body includes stacked positive electrode sheets, negative electrode sheets, and layers of separators spaced between each adjacent positive electrode sheet and negative electrode sheet. The laminated body is placed on a predetermined curved positioning mold. Under the action of gravity, each layer of electrode sheets and separators are in a shape consistent with the curved surface of the positioning mold. The exposed areas of each electrode sheet of the laminated body are stacked on the side of the laminated body. In this embodiment, the laminated body can also be shaped, but not limited to, such as but not limited to hot pressing; after the laminated body is placed in the metal shell 1, it can naturally be curved under the action of the curved surface of the shell bottom 13.

[0061] In order to facilitate the connection between the cover plate assembly and the laminate body, a pole ear 3 made of a metal sheet can be welded on the bottom surface of the cover plate assembly in advance, one end of the pole ear 3 is welded to the bottom surface of the first metal cover plate 21 and the second metal cover plate 22 respectively, and the other end extends out of the cover plate assembly. When connecting, the two pole ears 3 on the bottom surface of the cover plate assembly are respectively aligned with the exposed area of ​​the stacked pole pieces on the laminate body side, and the two pole ears 3 are respectively welded together with the exposed area of ​​the pole pieces they are facing, and then the welded pole ears 3 and the exposed area of ​​the pole pieces are cut off, and the connection position and the periphery of the laminate body are insulated to avoid contact with the metal shell, and the electrode welding of the laminate body is completed.

[0062] Generally, the positive electrode of the laminate is connected to the second metal cover plate 22 located at the center of the cover plate assembly 2, and the negative electrode of the laminate is connected to the first metal cover plate 21 located at the periphery. The laminate is placed in the metal shell 1. The bottom surface of the laminate matches the curved surface of the shell bottom 13 and is face-to-face with each other, thereby making full use of the space in the shell and increasing the capacity of the lithium-ion battery.

[0063] After the stack is placed, the cover plate assembly 2 is covered on the open end of the metal shell 1, that is, the stack is sealed in the shell to obtain a lithium ion battery.

[0064] Compared with the technical solution of sealing the bottom surface of the cover assembly 2 with the end surface of the side wall 12 located at the open end, this embodiment provides a technical solution of setting a step 11 lower than the side wall 12 on the inner wall of the side wall 12 of the metal shell 1. The side wall 12 limits the cover assembly 2 on the step 11 between the side walls 12, ensuring the contact surface of the cover assembly 2 with the step 11, which is conducive to improving the accuracy of positioning and sealing and improving work efficiency.

[0065] In particular, after sealing, the cover assembly 2 of the present embodiment is a curved surface. A cover assembly 2 having an area larger than the cross-sectional area of ​​the opening of the metal shell 1 can be used. The outer peripheral edge of the cover assembly 2 is positioned by the side wall 12 of the metal shell 1 to deform the cover assembly 2 into a curved surface. This scheme is further beneficial to the positioning of the cover assembly 2 and the metal shell 1, improves the reliability of the sealing connection between the cover assembly 2 and the metal shell 1, and facilitates operation.

[0066] As an illustration of this embodiment, it is preferred but not limited to make the cover plate assembly 2 sealed at the open end of the metal shell 1 a curved surface parallel to the shell bottom 13. The height of the cavity in the metal shell 1 is consistent at all locations, which is conducive to increasing the thickness of the laminate and the capacity of the lithium-ion battery.

[0067] The top surface of the cover plate assembly 2 may be, but is not limited to, flush or substantially flush with the top end surface of the side wall 12 of the metal shell 1 .

[0068] As an illustration of this embodiment, referring to the figure, the edges of the opening ends of the front and rear side walls 12 of the metal shell 1 of this embodiment located at the shell bottom 13 and the shell top are respectively parallel arcs, and accordingly, the shell bottom 13 and the cover plate combination located at the shell top are respectively parallel arc surfaces.

[0069] The lithium-ion battery of this embodiment may use a solid electrolyte or an electrolyte. When the electrolyte is used, after the two electrodes of the laminate are respectively welded to the bottom surfaces of the two cover plates of the cover plate assembly, the electrolyte is poured from the opening of the metal shell 1 to fully infiltrate the laminate in the shell, and after the electrolyte is poured, the cover plate assembly 2 is sealed to the opening of the metal shell 1.

[0070] It is also preferred but not limited to provide a through hole at the bottom 13 of the metal shell 1 as an injection hole for injecting electrolyte. In this way, before injecting the electrolyte, the cover plate assembly 2 is first sealed and connected to the open end of the metal shell 1, and then the electrolyte is injected through the injection hole 41 of the shell bottom 13. After the electrolyte injection is completed, a curved metal sheet with an area larger than the injection hole and matching the curved surface of the area is used to seal the injection hole. Specifically, a closed annular sealing track is formed on the curved metal sheet, and the sealing track surrounds the injection hole and has a predetermined spacing with the injection hole. In the sealing track area, the metal of the contact surface of the curved metal sheet and the shell bottom 13 is melted and sealed, and the injection hole is sealed below the curved metal sheet. The use of this injection hole scheme is conducive to avoiding the problem of electrolyte contaminating the sealing contact surface of the cover plate assembly 2 and the metal cover plate and affecting the reliability of the sealing combination, which is conducive to improving the sealing of lithium-ion batteries.

[0071] As an illustration of this embodiment, the top surfaces of the first metal cover plate 21 and the second metal cover plate 22 can be, but are not limited to, flush with each other, and the outer periphery of the second metal cover plate 22 exposed to the top surface has a certain distance from the first metal cover plate 21 (this area is the insulating layer 23) to facilitate external connection of the electrodes of the lithium-ion battery.

[0072] As an illustration of this embodiment, the first metal cover plate 21 and the second metal cover plate 22 of this embodiment can be made of, but not limited to, copper plates of uniform thickness. After the sheet-like insulating layer 23 and the second metal cover plate 22 are stacked on the bottom surface of the first metal cover plate 21, the second through hole 231 is located in the first through hole 211, and the second metal cover plate 22 is punched upward from the bottom surface of the second metal cover plate 22 facing the second through hole 231, so that the middle area of ​​the second metal cover plate 22 is deformed and bent upward toward the second through hole 231, forming a boss 221 limited in the second through hole 231, and the boss 221 is used as the external electrode of the lithium-ion battery. With this solution, since the air pressure in the shell of the second metal cover plate 22 increases during the application of the lithium-ion battery, the second metal cover plate 22 has a pressure acting on the first metal cover plate 21, so that the tightness of the connection between the first metal cover plate 21 and the second metal cover plate 22 is strengthened, which is conducive to improving the sealing of the cover plate assembly 2. In addition, a concave portion can be formed on the bottom surface of the second metal cover plate 22 (i.e., the back side of the boss 221) (not shown in the figure because the edge of the concave portion is a curved surface), and the concave portion can also be used as the electrode ear welding space of the battery cell of the lithium-ion battery, making full use of the space of the cover plate assembly 2 as the electrode welding space without occupying the space in the shell, which is conducive to improving the space utilization rate of the shell and increasing the capacity of the lithium-ion battery. The boss 221 on the top surface of the second metal cover plate 22 is exposed to the top surface of the cover plate assembly 2 through the second through hole 231 for external connection.

[0073] As an illustration of this embodiment, a protruding electrode sheet may be further provided, which are respectively denoted as a first electrode sheet and a second electrode sheet. One end of the two electrodes are respectively connected to the top surfaces of the first metal cover plate and the second metal cover plate, and the other ends are respectively extended out of the shell for external welding connection. An insulating sheet 5 is interposed between the second electrode sheet and the top surface of the first metal cover plate.

[0074] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A housing suitable for a lithium-ion battery, characterized in that: include: A metal shell, wherein the opening end of the metal shell is the top, the shell bottom of the metal shell is a curved surface, and at the opening end of the metal shell, a step lower than the side wall is provided on the inner wall of the side wall, the step surrounds the side wall in a closed ring, and the height from each part of the step to the shell bottom is the same, A cover plate assembly comprises a first metal cover plate, a second metal cover plate and an insulating layer, wherein the outer edge of the first metal cover plate is the outer edge of the cover plate assembly, a through hole is respectively provided on the first metal cover plate and the insulating layer, the second metal cover plate seals the two through holes, the insulating layer is sealed and combined between the first metal cover plate and the second metal cover plate, and the top surface and the bottom surface of the second metal cover plate are respectively exposed to the top surface and the bottom surface of the cover plate assembly through the two through holes, The cover plate assembly is located between the side walls of the metal shell, the bottom surface of the outer edge of the first metal cover plate is in face-to-face contact with the step, the metals of the contact surfaces are melted and sealed, and the cover plate assembly seals the opening of the metal shell.

2. The housing suitable for lithium-ion batteries according to claim 1, characterized in that: The cover plate assembly is a curved surface parallel to the shell bottom.

3. The housing suitable for lithium-ion batteries according to claim 1, characterized in that: Also included are curved metal sheets, A penetrating injection hole is provided on the shell bottom, and the metal sheet covers the shell bottom in face-to-face contact. A sealing track is formed on the metal sheet, and the sealing track completely surrounds the injection hole and is at a predetermined distance from the injection hole. In the sealing track area, the metal of the contact surface between the metal sheet and the shell bottom is melted and sealed.

4. The housing for lithium-ion batteries according to claim 1, characterized in that: On the top surface of the cover plate assembly, the top surfaces of the first metal cover plate and the second metal cover plate are flush with each other, and the outer periphery of the second metal cover plate exposed on the top surface of the cover plate assembly has a predetermined distance from the first metal cover plate.

5. The housing suitable for lithium-ion batteries according to claim 1, characterized in that: The second metal cover plate is sealed and bonded to the bottom surface of the first metal cover plate through the insulating layer, and the bottom surface of the second metal cover plate is completely exposed from the bottom surface of the cover plate assembly. The area of ​​the second metal cover plate facing the through hole of the insulating layer bulges toward the top, forming a boss on the top surface of the second metal cover plate and a recess opposite to the boss on the bottom surface of the second metal cover plate, and the top of the boss is exposed to the top surface of the cover plate assembly through the through hole of the insulating layer.

6. The housing for lithium-ion batteries according to claim 1, characterized in that: The edges of the opening ends of at least two opposite side walls of the metal shell at the shell bottom and the shell top and the step are in parallel arc shapes, and the outer edge of the cover plate assembly sealed on the metal shell is in an arc shape.

7. A lithium-ion battery, comprising: The housing according to any one of claims 1 to 6, The lithium-ion battery stack is filled with electrolyte, and the bottom surface of the stack is curved and abuts against the bottom of the shell. The two electrodes of the laminated body are respectively connected to the bottom surfaces of the first metal cover plate and the second metal cover plate of the cover plate assembly of the shell.

8. The lithium-ion battery according to claim 7, characterized in that: It also includes a first electrode sheet and a second electrode sheet, one end of which is respectively connected to the top surface of the first metal cover plate and the second metal cover plate, and the other end extends out of the shell for external connection, and an insulating sheet is spaced between the second electrode sheet and the top surface of the first metal cover plate.

9. The lithium-ion battery according to claim 7, characterized in that: The second metal cover plate is sealed and bonded to the bottom surface of the first metal cover plate through the insulating layer, and the bottom surface of the second metal cover plate is completely exposed from the bottom surface of the cover plate assembly. The area of ​​the second metal cover plate facing the through hole of the insulating layer protrudes toward the top, forming a boss on the top surface of the second metal cover plate, and the top of the boss is exposed to the top surface of the cover plate assembly through the through hole of the insulating layer. The positive electrode of the stack is welded to the bottom surface of the second metal cover plate, and the negative electrode is connected to the bottom surface of the second metal cover plate or the inner wall of the metal shell.

10. An electronic product, characterized in that: The battery chamber of the electronic product is provided with the lithium-ion battery according to claim 7, 8 or 9, the shell wall of the lithium-ion battery shell is in contact with the inner wall of the battery chamber, and the electrodes of the lithium-ion battery are electrically connected to the circuit module of the electronic product.

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