Adapter piece and battery

Abstract

The invention relates to an adapter piece and a battery, the adapter piece comprises an adapter piece body and a plurality of pyramid protrusions, the adapter piece body comprises a first surface and a second surface which are used as two opposite side surfaces of the adapter piece body, the first surface is provided with a laser incidence area for laser beam incidence, and the plurality of pyramid protrusions are all arranged on the laser incidence area; the battery comprises the adapter piece. According to the adapter piece and the battery, the plurality of pyramid bulges with the consistent morphology are arranged on the laser incidence area of the adapter piece body, so that a uniform molten pool morphology is formed, the uniformity of energy obtained in the welding process is ensured, and the contact area between laser and the adapter piece body can be increased by utilizing the pyramid structures of the pyramid bulges; and the laser can be reflected from one pyramid bulge to the next pyramid bulge, so that the utilization rate of energy is increased, the energy loss is reduced, and the problems of poor welding and incapability of detecting poor conditions such as insufficient welding and broken welding are effectively solved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an adapter and a battery. Background Art

[0002] With the development of modern society and the enhancement of people's environmental awareness, more and more devices choose lithium-ion batteries as power sources, which provides broad space for the application and development of lithium-ion batteries.

[0003] At present, during the manufacturing process of lithium batteries, adapters are often used in combination with laser welding to achieve the connection between the battery core and the cover plate. However, the adapters in the prior art are generally copper or aluminum sheets. Since the surface of the adapter material is relatively smooth, the laser will be reflected by the mirror after being incident on the surface of the adapter, thereby losing most of the energy, resulting in poor welding such as cold welding. In addition, the smooth surface of the adapter will also make it impossible to detect whether there are bad conditions such as cold welding and broken welding during the visual inspection process. Summary of the invention

[0004] Based on this, it is necessary to provide an adapter and a battery to address the problems of poor welding between the core and the cover during the welding process and the inability to detect whether there are poor welds or broken welds.

[0005] According to one aspect of the present application, there is provided a transfer sheet, comprising a transfer sheet body;

[0006] The adapter plate body has a first surface and a second surface that are arranged opposite to each other. The first surface has a laser incident area for incident laser beams. The laser incident area is provided with a plurality of pyramidal protrusions.

[0007] In one embodiment, the pyramid protrusion is a quadrangular pyramid structure.

[0008] In one embodiment, the pyramid protrusion includes a first side, a second side, a third side and a fourth side extending from the vertex to the first surface, and the first side, the second side, the third side and the fourth side are all arranged toward the incident direction of the laser beam.

[0009] In one embodiment, the first surface also has a welding area, and the first side surface, the second side surface, the third side surface and the fourth side surface are arranged in sequence along the circumferential direction of the side of the pyramid protrusion. The distance between the first side surface and the welding area is greater than the distance between the third side surface and the welding area, and the distance between the second side surface and the welding area is equal to the distance between the fourth side surface and the welding area.

[0010] In one embodiment, the angle between the first side surface and the first surface is greater than the angle between the third side surface and the first surface.

[0011] In one embodiment, the angle between the second side surface and the first surface is equal to the angle between the fourth side surface and the first surface.

[0012] In one embodiment, the distance between the vertex and the first surface is greater than 0.5 mm and less than 0.1 mm.

[0013] In one embodiment, a plurality of pyramidal protrusions are arranged at equal intervals in a horizontal direction and a vertical direction, the horizontal direction is parallel to the first surface, and the vertical direction is perpendicular to the horizontal direction and parallel to the first surface.

[0014] In one embodiment, two adjacent pyramidal protrusions along the horizontal direction are connected to each other and / or two adjacent pyramidal protrusions along the vertical direction are connected to each other.

[0015] According to another aspect of the present application, a battery is provided, comprising a switching piece as described in any one of the above embodiments.

[0016] The above-mentioned adapter and battery form a uniform molten pool morphology by arranging a number of pyramidal protrusions with consistent morphology on the laser incident area of ​​the adapter body to ensure the uniformity of energy obtained during the welding process. The pyramidal structure of the pyramidal protrusions can be used to increase the contact area between the laser and the adapter body, and the laser can be reflected from one of the pyramidal protrusions to the next pyramidal protrusion, thereby increasing energy utilization and reducing energy loss, thereby effectively solving the problem of poor welding and the inability to detect whether there are adverse conditions such as cold welding and broken welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic diagram of the structure of an adapter sheet according to some embodiments of the present application.

[0018] FIG. 2 is a schematic structural diagram of several pyramidal protrusions of an adapter sheet according to some embodiments of the present application.

[0019] FIG. 3 is a schematic structural diagram of a partial cross section of an adapter sheet in some embodiments of the present application.

[0020] FIG. 4 is a schematic structural diagram of a partial cross section of an adapter sheet in some embodiments of the present application from another viewing angle.

[0021] Reference numerals:

[0022] 1. adapter body; 11. first surface; 12. laser incident area; 13. welding area;

[0023] 2. Pyramidal protrusion; 21. First side surface; 22. Second side surface; 23. Third side surface; 24. Fourth side surface; 25. Vertex. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0025] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0026] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0030] With the development of modern society and the enhancement of people's environmental awareness, more and more devices choose lithium-ion batteries as power sources, such as mobile phones, laptops, power tools and electric vehicles, etc., which provides a broad space for the application and development of lithium-ion batteries. At present, the role of the adapter in lithium batteries includes: connecting the battery cover and the battery cell, that is, the adapter, as a key component connecting the battery cover and the battery cell, must simultaneously meet the battery's overcurrent, strength and low spatter requirements. Carrying current: The adapter needs to carry current, so during the welding process, there needs to be sufficient weld width and no foreign matter falling on the battery cell to avoid the abnormality of battery short circuit. Welding quality requirements: During the welding process, the welding quality of the adapter directly affects the performance and safety of the battery. During welding, it is necessary to prevent spatter, meet the low spatter conditions, and it must be ensured that no spatter will splash onto the battery cell, otherwise there will be a serious consequence of battery short circuit. Structural strength: The adapter needs to maintain a certain structural strength after welding to ensure the stability and safety of the battery when it is subjected to external impact. Fine control of welding process: The welding process of the adapter needs to be precisely controlled to ensure the uniformity and quality of welding, which is crucial to the overall performance and reliability of the battery. In summary, the adapter plays the role of connection, current carrying, welding quality assurance, structural strength and fine welding control in the laser welding process. It is an indispensable key component in the power battery manufacturing process.

[0031] It is understandable that in the current manufacturing process of batteries, adapters are often used in conjunction with laser welding to achieve the connection between the battery core and the cover plate. However, since the material of the adapter needs to match the material of the battery's pole ears and poles, it is usually aluminum, copper or alloy materials to ensure the welding quality and the reliability of the electrical connection. Therefore, the adapter in the prior art is generally a copper sheet or an aluminum sheet. However, since the surface of the adapter material is relatively smooth, the laser will be mirror-reflected after being incident on the surface of the adapter, and most of the energy will be lost, resulting in poor welding such as cold welding. If the fusion of the welding part is guaranteed by increasing the laser welding power, welding defects such as explosion points and welding penetration are prone to occur. In addition, the smooth surface of the adapter will also cause problems such as the inability to detect whether there are undesirable conditions such as cold welding and broken welding during the CCD visual inspection process.

[0032] Therefore, there is an urgent need for an adapter to reduce energy loss during the welding process, and there is no need to increase the laser welding power to ensure the fusion of the welding parts, to solve the problems of poor welding such as cold welding, welding defects such as explosion points and weld penetration, and the inability to detect whether there are cold welding and broken welding during CCD visual inspection.

[0033] Referring to FIG. 1 , an embodiment of the present application provides an adapter sheet, including an adapter sheet body 1 and a plurality of pyramidal protrusions 2. The adapter sheet body 1 is used to cooperate with laser welding to realize the connection between the battery core and the cover plate. During welding, the laser welding head can be opposite to the laser incident area 12 of the adapter sheet, so that the laser beam emitted by the laser welding head is irradiated to the laser incident area 12 of the adapter sheet, thereby utilizing the heat generated by the laser beam to realize the welding of the battery core and the cover plate. The plurality of pyramidal protrusions 2 are used to increase the contact area between the laser and the adapter sheet body 1, increase the energy utilization rate, and reduce energy loss.

[0034] In the specific configuration, the adapter body 1 includes a first surface 11 and a second surface as two opposite side surfaces thereof. The first surface 11 has a laser incident area 12 for incident laser beams, and a plurality of pyramidal protrusions 2 are arranged on the laser incident area 12 .

[0035] Specifically, the first surface 11 has a laser incident area 12 and a welding area 13. The laser beam emitted by the laser welding head irradiates the laser incident area 12, and uses the heat generated by the laser beam to achieve welding of the battery core and the cover plate in the welding area 13. It can be understood that in the embodiment of the present application, the ratio of the area of ​​the laser incident area 12 to the area of ​​the first side surface 21 is less than one-half, and the ratio of the area of ​​the welding area 13 to the area of ​​the first side surface 21 is less than one-half.

[0036] The adapter of the present application forms a uniform molten pool morphology by setting a plurality of pyramidal protrusions 2 with the same morphology on the laser incident area 12 of the adapter body 1, thereby ensuring the uniformity of energy obtained during welding. In addition, the adapter body 1 can use the pyramidal structure of the pyramidal protrusions 2 to increase the contact area between the laser and the adapter body 1, and make the laser reflect from one of the pyramidal protrusions 2 to the next pyramidal protrusion 2, thereby increasing the utilization rate of energy and reducing energy loss, thereby effectively solving the problem of poor welding and the inability to detect whether there are poor conditions such as cold welding and broken welding.

[0037] It is worth noting that although there is currently a technology for improving energy utilization by roughening the laser incident area 12 of the adapter to form a rough surface, and reflecting the laser beam through the rough surface, the rough surface cannot guarantee that the energy will be reflected from one rough protrusion to the next rough protrusion, and therefore the effect of improving energy utilization as a whole in the present application cannot be achieved.

[0038] Referring to FIG. 1 and FIG. 2 , in one embodiment, the pyramid protrusion 2 is a quadrangular pyramid structure. Compared with a triangular pyramid structure, the quadrangular pyramid structure can provide the pyramid protrusion 2 with more surfaces for reflection of the laser, thereby increasing the energy utilization rate. Compared with a pentagonal pyramid, a hexagonal pyramid, a heptagonal pyramid, etc. structure, the quadrangular pyramid structure can prevent the laser from being reflected too dispersed, thereby affecting the welding effect.

[0039] Specifically, the pyramid protrusion 2 is a right quadrangular pyramid structure. The edges of the right quadrangular pyramid all intersect at the apex, and each side surface intersects perpendicularly with the edge of the bottom surface, which means that the vertex 25 of the right quadrangular pyramid is directly located above a vertex 25 of the bottom surface, and the side surface is perpendicular to the bottom surface. By making the pyramid protrusion 2 a right quadrangular pyramid structure, it is ensured that the four side surfaces of the pyramid protrusion 2 can be arranged toward the incident direction of the laser beam, so that the four side surfaces can reflect the laser beam, thereby ensuring the energy utilization rate.

[0040] That is, it can be understood that, referring to Figures 2 to 4, in the embodiments of the present application, the pyramidal protrusion 2 includes a first side 21, a second side 22, a third side 23 and a fourth side 24 extending from the vertex 25 to the first surface 11, and the first side 21, the second side 22, the third side 23 and the fourth side 24 are all arranged in the incident direction of the laser beam, so that when the laser beam is irradiated into the laser incident area 12 of the adapter, the first side 21, the second side 22, the third side 23 and the fourth side 24 of the pyramidal protrusion 2 can all reflect the laser beam, thereby ensuring the energy utilization and further ensuring the effect of the laser beam on the welding of the battery core and the cover plate.

[0041] In one embodiment, the first side surface 21, the second side surface 22, the third side surface 23 and the fourth side surface 24 are sequentially arranged along the circumferential direction of the pyramid protrusion 2. The first surface 11 also has a welding area 13, the distance between the first side surface 21 and the welding area 13 is greater than the distance between the third side surface 23 and the welding area 13, and the distance between the second side surface 22 and the welding area 13 is equal to the distance between the fourth side surface 24 and the welding area 13.

[0042] Specifically, the two sides of the first side 21 are respectively connected to the second side 22 and the fourth side 24, the two sides of the second side 22 are respectively connected to the first side 21 and the third side 23, the two sides of the third side 23 are respectively connected to the second side 22 and the fourth side 24, and the two sides of the fourth side 24 are respectively connected to the first side 21 and the third side 23.

[0043] Referring to FIG. 2-FIG. 3, in one embodiment, the angle between the first side surface 21 and the first surface 11 is greater than the angle between the third side surface 23 and the first surface 11. Specifically, the angle between the first side surface 21 and the first surface 11 is an acute angle, and the angle between the third side surface 23 and the first surface 11 is an acute angle. More specifically, the angle between the first side surface 21 and the first surface 11 is greater than 45°, and the angle between the third side surface 23 and the first surface 11 is less than 45°. This structure can cause the laser to be reflected more than once on the first side surface 21 and the third side surface 23, thereby improving the overall energy utilization.

[0044] Referring to FIG. 2 and FIG. 4 , in one embodiment, the angle between the second side surface 22 and the first surface 11 is equal to the angle between the fourth side surface 24 and the first surface 11. Specifically, the angle between the second side surface 22 and the first surface 11 is an acute angle. More specifically, the angle between the second side surface 22 and the first surface 11 is less than 45°. This structure can increase the area where the laser contacts the second side surface 22 and the fourth side surface 24, and enables the laser to be reflected onto the next pyramid protrusion 2, thereby increasing the utilization rate of energy.

[0045] In one embodiment, the distance between the vertex 25 and the first surface 11 is greater than 0.5 mm and less than 0.1 mm. Specifically, a groove is provided on the first surface 11 of the adapter body 1, and the plurality of pyramidal protrusions 2 are arranged in the groove, and the depth of the groove is greater than 0.5 mm and less than 0.1 mm. This distance can ensure that the laser has a reasonable number of reflections, and the welding effect will not be affected by too many reflections.

[0046] Referring to Fig. 1-Fig. 2, in one embodiment, a plurality of pyramidal protrusions 2 are arranged at equal intervals in the horizontal direction and the vertical direction, the horizontal direction is parallel to the first surface 11, and the vertical direction is perpendicular to the horizontal direction and parallel to the first surface 11. This structure enables the plurality of pyramidal protrusions 2 to be arranged in a matrix structure, ensuring the continuity and consistency of the plurality of pyramidal protrusions 2, and easily forming a consistent molten pool morphology, thereby ensuring the stability of welding.

[0047] In one of the embodiments, two adjacent pyramidal protrusions 2 in the horizontal direction are connected to each other. Two adjacent pyramidal protrusions 2 in the vertical direction are connected to each other. Specifically, the third side surface 23 of one of the pyramidal protrusions 2 is connected to the first side surface 21 of another adjacent pyramidal protrusion 2. The second side surface 22 of one of the pyramidal protrusions 2 is connected to the fourth side surface 24 of another adjacent pyramidal protrusion 2. This structure can reduce the distance between adjacent pyramidal protrusions 2 and pyramidal protrusions 2, ensuring that energy will be reflected from one of the pyramidal protrusions 2 to the next pyramidal protrusion 2, thereby improving the overall energy utilization.

[0048] It is worth noting that although there is currently a technology for improving energy utilization by roughening the laser incident area 12 of the adapter to form a rough surface, and reflecting the laser beam through the rough surface, the rough surface cannot guarantee that the energy will be reflected from one rough protrusion to the next rough protrusion, and therefore the effect of improving energy utilization as a whole in the present application cannot be achieved.

[0049] The embodiments of the present application also provide a battery, comprising an adapter sheet as in any one of the embodiments described above. Specifically, the adapter sheet comprises an adapter sheet body 1 and a plurality of pyramidal protrusions 2. The adapter sheet body 1 is used to cooperate with laser welding to realize the connection between the battery roll core and the cover plate. During welding, the laser welding head can be made opposite to the laser incident area 12 of the adapter sheet, so that the laser beam emitted by the laser welding head is irradiated to the laser incident area 12 of the adapter sheet, thereby utilizing the heat generated by the laser beam to realize the welding of the battery roll core and the cover plate. The plurality of pyramidal protrusions 2 are used to increase the contact area between the laser and the adapter sheet body 1, increase the energy utilization rate, and reduce energy loss.

[0050] 1-2 , in a specific configuration, the adapter body 1 includes a first surface 11 and a second surface as two opposite side surfaces thereof, the first surface 11 has a laser incident area 12 for incident laser beams, and a plurality of pyramidal protrusions 2 are arranged on the laser incident area 12 .

[0051] Specifically, the first surface 11 has a laser incident area 12 and a welding area 13. The laser beam emitted by the laser welding head irradiates the laser incident area 12, and uses the heat generated by the laser beam to achieve welding of the battery core and the cover plate in the welding area 13. It can be understood that in the embodiment of the present application, the ratio of the area of ​​the laser incident area 12 to the area of ​​the first side surface 21 is less than one-half, and the ratio of the area of ​​the welding area 13 to the area of ​​the first side surface 21 is less than one-half.

[0052] In one embodiment, the pyramid protrusion 2 is a quadrangular pyramid structure. Compared with a triangular pyramid structure, the quadrangular pyramid structure can provide the pyramid protrusion 2 with more surfaces for reflection to increase energy utilization. Compared with a pentagonal pyramid, a hexagonal pyramid, a heptagonal pyramid, etc., the quadrangular pyramid structure can prevent the laser from being reflected too dispersed, thereby affecting the welding effect.

[0053] Specifically, the pyramid protrusion 2 is a right quadrangular pyramid structure. The edges of the right quadrangular pyramid all intersect at the apex, and each side surface intersects perpendicularly with the edge of the bottom surface, which means that the vertex 25 of the right quadrangular pyramid is directly located above a vertex 25 of the bottom surface, and the side surface is perpendicular to the bottom surface. By making the pyramid protrusion 2 a right quadrangular pyramid structure, it is ensured that the four side surfaces of the pyramid protrusion 2 can be arranged toward the incident direction of the laser beam, so that the four side surfaces can reflect the laser beam, thereby ensuring the energy utilization rate.

[0054] That is, it can be understood that, referring to Figures 2 to 4, in the embodiments of the present application, the pyramidal protrusion 2 includes a first side 21, a second side 22, a third side 23 and a fourth side 24 extending from the vertex 25 to the first surface 11, and the first side 21, the second side 22, the third side 23 and the fourth side 24 are all arranged in the incident direction of the laser beam, so that when the laser beam is irradiated into the laser incident area 12 of the adapter, the first side 21, the second side 22, the third side 23 and the fourth side 24 of the pyramidal protrusion 2 can all reflect the laser beam, thereby ensuring the energy utilization and further ensuring the effect of the laser beam on the welding of the battery core and the cover plate.

[0055] In one embodiment, the first side surface 21, the second side surface 22, the third side surface 23 and the fourth side surface 24 are sequentially arranged along the circumferential direction of the pyramid protrusion 2. The first surface 11 also has a welding area 13, the distance between the first side surface 21 and the welding area 13 is greater than the distance between the third side surface 23 and the welding area 13, and the distance between the second side surface 22 and the welding area 13 is equal to the distance between the fourth side surface 24 and the welding area 13.

[0056] The angle between the first side surface 21 and the first surface 11 is greater than the angle between the third side surface 23 and the first surface 11. This structure can make the laser reflect more than once on the first side surface 21 and the third side surface 23, thereby improving the energy utilization rate as a whole. The angle between the second side surface 22 and the first surface 11 is equal to the angle between the fourth side surface 24 and the first surface 11. This structure can increase the area of ​​the laser contacting the second side surface 22 and the fourth side surface 24, and enable the laser to be reflected on the next pyramid protrusion 2, thereby increasing the energy utilization rate.

[0057] In summary, the battery of the present application forms a uniform molten pool morphology by arranging a number of pyramidal protrusions 2 with consistent morphology on the laser incident area 12 of the adapter body 1, thereby ensuring the uniformity of energy obtained during the welding process. The pyramidal structure of the pyramidal protrusions 2 can be used to increase the contact area between the laser and the adapter body 1, and the laser can be reflected from one of the pyramidal protrusions 2 to the next pyramidal protrusion 2, thereby increasing energy utilization and reducing energy loss, thereby effectively solving the problem of poor welding and the inability to detect whether there are adverse conditions such as cold welds and broken welds.

[0058] It is worth noting that although there is currently a technology for improving energy utilization by roughening the laser incident area 12 of the adapter to form a rough surface, and reflecting the laser beam through the rough surface, the rough surface cannot guarantee that the energy will be reflected from one rough protrusion to the next rough protrusion, and therefore the effect of improving energy utilization as a whole in the present application cannot be achieved.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A transfer sheet, characterized in that: include: The adapter plate body has a first surface and a second surface that are arranged opposite to each other. The first surface has a laser incident area for incident laser beams. The laser incident area is provided with a plurality of pyramidal protrusions.

2. The adapter according to claim 1, characterized in that: The pyramid protrusion is a quadrangular pyramid structure.

3. The adapter according to claim 2, characterized in that: The pyramid protrusion includes a first side surface, a second side surface, a third side surface and a fourth side surface extending from the vertex toward the first surface, and the first side surface, the second side surface, the third side surface and the fourth side surface are all arranged toward the incident direction of the laser beam.

4. The adapter according to claim 3, characterized in that: The first surface also has a welding area, and the first side surface, the second side surface, the third side surface and the fourth side surface are arranged in sequence along the circumferential direction of the side of the pyramid protrusion. The distance between the first side surface and the welding area is greater than the distance between the third side surface and the welding area, and the distance between the second side surface and the welding area is equal to the distance between the fourth side surface and the welding area.

5. The adapter according to claim 4, characterized in that: An included angle between the first side surface and the first surface is greater than an included angle between the third side surface and the first surface.

6. The adapter according to claim 4, characterized in that: The included angle between the second side surface and the first surface is equal to the included angle between the fourth side surface and the first surface.

7. The adapter according to claim 3, characterized in that: The distance between the vertex and the first surface is greater than 0.5 mm and less than 0.1 mm.

8. The adapter according to claim 1, characterized in that: The plurality of pyramid protrusions are arranged at equal intervals in the horizontal direction and the vertical direction. The horizontal direction is parallel to the first surface, and the vertical direction is perpendicular to the horizontal direction and parallel to the first surface.

9. The adapter according to claim 8, characterized in that: Two adjacent pyramid protrusions along the horizontal direction are connected to each other and / or two adjacent pyramid protrusions along the vertical direction are connected to each other.

10. A battery, characterized in that: Comprising the adapter sheet as described in any one of claims 1 to 9.

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