Cylinder and shell for high-capacity battery and high-capacity battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a cylinder and a shell for a high-capacity battery and the high-capacity battery. The barrel comprises a barrel main body and at least one rib fixed on the barrel main body; two opposite ends of the cylinder main body are open ends; the end faces of the ribs and the end face of the open end of the barrel are located on the same plane and serve as friction stir welding feed points and retracting points. The shell comprises the cylinder and an end plate sealed at the open end of the cylinder. The high-capacity battery comprises a shell and a single battery positioned in the shell; the end plate is sealed and fixed at the open end of the cylinder body in a friction stir welding manner, so that the strength and the sealing performance of a welding seam are improved; and after welding is completed, the rib serving as the arc suppression plate does not need to be cut off, the post-processing work of welding is simplified, and the overall welding efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the battery field, specifically is a large capacity battery cylinder, shell and large capacity battery. BACKGROUND

[0002] At present, many single batteries are connected in parallel or series to form a large capacity battery (also known as a battery module or battery pack) on the market.

[0003] However, there are differences between each single battery in the existing large capacity battery, and due to the existence of the bucket effect, the performance of the worst single battery often affects the entire large capacity battery, resulting in a great limitation of the capacity upper limit and cycle times of the entire large capacity battery. Therefore, how to improve the uniformity of each single battery in the large capacity battery has become the focus and difficulty of research in this field.

[0004] In order to solve the above problems, a large capacity battery is provided in Chinese patent CN220797038U, as shown in the figure, which includes a shell body 01 and a plurality of single batteries; the plurality of single batteries are placed in the shell body 01, and the shell body top plate 02 (the second cover plate in CN220797038U) is provided with a third through hole corresponding to the pole of each single battery for the pole of the single battery to extend out of the shell body 01; each single battery pole extends out of the third through hole, and the region of the shell body 01 corresponding to the third through hole is fixed and sealed with the single battery shell. Figure 1

[0005] The shell body bottom plate 03 is provided with an electrolyte sharing chamber 04, and the electrolyte sharing chamber 04 and the electrolyte area of each single battery inner cavity are in communication, so that each single battery is in a unified electrolyte environment through the electrolyte sharing chamber 04, ensuring the uniformity of the electrolyte in each single battery and improving the performance and cycle life of the large capacity battery.

[0006] A gas chamber 05 can also be provided on the shell body top plate 02, which can be in communication with the gas area of each single battery inner cavity to achieve gas balance of each single battery, further improving the performance and cycle life of the large capacity battery. The gas chamber 05 can also serve as a venting channel, when thermal runaway occurs in any single battery, the thermal runaway flue gas in the single battery inner cavity enters the gas chamber 05 and breaks through the venting mechanism provided at either end of the gas chamber 05, and is discharged.

[0007] In one embodiment of CN220797038U, the shell body 01 is composed of a cylinder and end plates (first cover plate and third cover plate in CN220797038U) sealed and welded at both ends thereof.

[0008] In order to ensure that the electrolyte in the inner cavity of the shell body 01 is not affected by the external environment, the strength and sealing performance of the welded part of the shell body 01 are particularly important.​ Utility model content

[0009] The utility model discloses a cylinder for large capacity battery, shell and large capacity battery improve the strength and leakproofness of shell weld part.

[0010] The utility model discloses a concept is:

[0011] Cylinder and end plate can adopt laser welding, electric arc welding, friction stir welding and common welding method of stirring;

[0012] Compared with laser welding, electric arc welding, friction stir welding mainly has following advantages in cylinder and end plate welding:

[0013] 1, friction stir welding is a solid phase welding technology, in the welding process, can avoid the blowhole, slag and other defects in laser welding, electric arc welding. This makes the weld strength higher, can better satisfy the stress requirement of cylinder and end plate in the use process.

[0014] 2, laser welding and electric arc welding produce a large amount of heat in the welding process, cause the welding area and the surrounding material to heat expansion, contract after cooling, thus produce larger welding deformation. And the heat input of friction stir welding is relatively low, and the heat generated in the welding process is mainly concentrated in the local area of the stirring head and the cylinder, end plate contact, and the influence on the surrounding structure is smaller. Therefore, the deformation of cylinder and end plate after welding is very small.

[0015] Based on the above analysis, the utility model adopts the mode of friction stir welding to weld the end plate on the open end of the cylinder.

[0016] In addition, arc extinguishing is a key finishing step in friction stir welding. When the welding is about to end, the pressure of the stirring head on the workpiece needs to be gradually reduced, while the rotation of the stirring head is maintained, so that the stirring head slowly leaves the welding position. When the stirring head leaves the workpiece, if the operation is improper, shrinkage holes or loose defects may be formed at the end of the weld. In order to avoid these problems, in the prior art, special process is usually used at the end of welding, such as setting the arc collection plate, extending the welding process to the arc collection plate, and then stopping the rotation of the stirring head when the stirring head enters the arc collection plate from the main body of the workpiece. In this way, the discontinuous part at the end of the weld can be left on the arc collection plate, so as to ensure the quality of the weld of the main body of the workpiece. After welding is completed, the arc collection plate is cut off.

[0017] However, the operation process of cutting off the arc collection plate after the arc collection plate is arranged in advance and welding is completed is relatively complex; meanwhile, the cutting off of the arc collection plate usually needs to use a cutting device, and if the operation is not proper, the welding quality may be affected, so after the arc collection plate is cut off, the welding seam needs to be detected and evaluated again to ensure that the welding quality meets the requirements. This not only increases the difficulty of quality control, but also prolongs the production cycle.

[0018] Based on this, the utility model considers that the rib is directly arranged as the arc collection plate at the to-be-welded part of the end face of the cylinder, the end face of the rib is located in the same plane as the end face of the open end of the cylinder, the end face of the rib is used as the tool entry point and the tool exit point of the friction stir welding, after the welding is completed, the arc collection plate does not need to be cut off, the problem that the cutting off of the arc collection plate affects the welding quality can be avoided, and meanwhile the post-processing work of welding is greatly simplified, thereby the overall welding efficiency is improved. For the case of batch production, the improvement of the efficiency is particularly obvious. The production cycle can be shortened, the yield can be improved, and the production cost can be reduced.

[0019] Based on the above-mentioned inventive concept, the utility model provides a cylinder for a large-capacity battery in a first aspect, which is characterized in that: comprising a cylinder main body and at least one rib fixed on the cylinder main body;

[0020] The cylinder main body has at least one open end;

[0021] The end face of the rib is located in the same plane as the end face of the open end of the cylinder and is used as the tool entry point and the tool exit point of the friction stir welding.

[0022] In a first aspect, as described above, the rib serving as the arc collection plate does not need to be cut off after the welding is completed, the post-processing work of welding is simplified, and the overall welding efficiency is improved. In a second aspect, the rib in the utility model can also play a role in enhancing the structural strength of the cylinder. In a third aspect, the tool entry point and the tool exit point are located at the same point, which can ensure the continuity and stability of the welding path. In a fourth aspect, the end face of the rib is located in the same plane as the end face of the open end of the cylinder, which can ensure that the mixing head stably cuts into the end face of the cylinder, so that the to-be-welded part is fully softened and forms a good plastic flow state in the initial stage, thereby improving the bonding strength of the welding seam at the starting position and avoiding defects such as incomplete penetration and porosity.

[0023] Further, the cylinder main body has two opposite open ends; the rib is one and extends along the length direction of the cylinder main body and is an integral part with the cylinder main body, which can be integrally formed by an aluminum extrusion process; the two end faces of the rib are located in the same plane as the end faces of the two open ends of the cylinder.

[0024] The ribs are integral with the cylinder body, meaning they are made of the same material. During the welding process, the consistency of the material's thermal physical properties and chemical composition is crucial for the quality of the weld. Since the ribs are integral with the cylinder body, there is no risk of weld defects caused by material differences.

[0025] The ribs being integral with the cylinder body allows for more stable control of the welding parameters. In traditional welding, the presence of the collection plate can affect the stability of the welding arc and the heat input, requiring adjustments to the welding parameters. The integral design eliminates this influence, allowing the welding parameters to remain stable throughout the welding process. This helps to improve the consistency of the weld quality and reduce the occurrence of welding defects.

[0026] Further, the cylinder body bottom plate is convex in the direction away from the cylinder body top plate, forming an electrolyte sharing chamber; the ribs are located between the cylinder body bottom plate and the outer side wall of the electrolyte sharing chamber.

[0027] The ribs being located between the cylinder body bottom plate and the outer side wall of the electrolyte sharing chamber can significantly enhance the structural strength of the cylinder body. Large capacity batteries may be subjected to various external forces during use, such as vibration, impact, and extrusion. The presence of ribs can effectively disperse these external forces, preventing the cylinder from deforming or breaking, and improving the safety and reliability of the large capacity battery.

[0028] In addition, the ribs can also support the outer side wall of the electrolyte sharing chamber, helping to maintain the shape and stability of the electrolyte sharing chamber.

[0029] At the same time, by placing the ribs between the cylinder body bottom plate and the outer side wall of the electrolyte sharing chamber, the maximum dimensions of the large capacity battery in the length, width, and height directions are not affected, thereby the capacity density is not affected.

[0030] Further, the cross section of the ribs is rectangular, with the side lengths being l1 and l2, (d+2) cm ≤ l1 ≤ (d+8) cm, (d+2) cm ≤ l2 ≤ (d+8) cm, where d is the diameter of the stirring pin used for friction stir welding.

[0031] The size of the cross section of the ribs is associated with the diameter of the stirring pin used for friction stir welding, which can better adapt to the process requirements of friction stir welding. By setting the side lengths of the cross section of the ribs within the above range, the ribs can ensure that the end face has enough area to accommodate the stirring pin, achieving good welding effect under the premise of reasonable material cost.

[0032] Further, a step structure is provided along the circumference of the end face of the open end of the cylinder body, wherein the step face can serve as a positioning face for the end plate.

[0033] Further, the main wall thickness of the cylinder body is h, wherein 4cm≤h≤8cm, in this range, the cylinder body pressure-bearing strength meets the set requirements, while having lower material cost.

[0034] The utility model discloses a second aspect provides a kind of shell for large capacity battery, its special feature is that: including end plate and above-mentioned cylinder;End plate is sealed and fixed in the open end of cylinder by friction stir welding, and weld strength and sealing performance are higher, can better meet the stress and sealing requirement of cylinder and end plate in use process.

[0035] Further, the end plate and the step surface of the step structure of the open end of the main body of the cylinder abut. In the process of friction stir welding, good positioning can be achieved based on the step surface, ensuring the stability of the welding process and improving the quality and performance of the weld.

[0036] The utility model discloses a third aspect provides a kind of large capacity battery, its special feature is that: including shell and n single batteries arranged in the shell along the same direction;Wherein the shell is above-mentioned shell, and n is the integer greater than 1.

[0037] The utility model has the beneficial effects that:

[0038] First, the utility model utilizes the process of friction stir welding to seal and fix the end plate in the open end of the cylinder, ensuring that the weld has high strength and sealing performance, while reducing the impact of the welding process on the single batteries in the shell. In addition, the utility model sets a rib on the cylinder as an arc collection plate, uses the end surface of the rib as the entry and exit points of friction stir welding, and after completing the welding, there is no need to cut off the arc collection plate, which can avoid the problem of affecting the quality of the weld caused by cutting off the arc collection plate, while greatly simplifying the post-processing work of welding, thereby improving the overall welding efficiency. For batch production, this efficiency improvement is particularly evident. It can shorten the production cycle, improve the yield and reduce the production cost. Second, the rib in the utility model can also enhance the structural strength of the cylinder. Third, the entry and exit points in the utility model are located at the same point, which can ensure the continuity and stability of the welding path. Fourth, the end surface of the rib and the end surface of the open end of the cylinder are located in the same plane, which can ensure that the friction stir welding head smoothly cuts into the end surface of the cylinder, so that the to-be-welded part is fully softened and forms a good plastic flow state in the initial stage, thereby improving the bonding strength of the starting point of the weld and avoiding defects such as incomplete penetration and porosity. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of large capacity battery in background art;

[0040] Figure 2 It is a structural schematic diagram of cylinder in embodiment 1;

[0041] Figure 3 is a sectional view of the cylinder in Example 1;

[0042] Figure 4 is a structural schematic view of a cylinder in other examples;

[0043] Figure 5 is a structural schematic view of another cylinder in other examples;

[0044] Figure 6 is a structural schematic view of the shell in Example 2;

[0045] Figure 7 is an exploded structural schematic view of the shell in Example 2;

[0046] Figure 8 is a structural schematic view of the large-capacity battery in Example 3;

[0047] Figure 9 is an exploded structural schematic view of the large-capacity battery in Example 3.

[0048] In the drawings:

[0049] 01, outer shell body; 02, outer shell body top plate; 03, outer shell body bottom plate; 04, electrolyte sharing chamber; 05, gas chamber;

[0050] 1, cylinder; 11, cylinder main body; 111, cylinder main body top plate; 112, cylinder main body bottom plate; 113, electrolyte sharing chamber; 114, electrolyte sharing chamber outer sidewall; 115, avoidance hole; 116, step structure; 12, rib; 2, end plate; 3, single battery cell; 31, polarity terminal; 4, heat transfer pipe; 5, shell. DETAILED DESCRIPTION

[0051] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0052] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced without the specific details, other than those described herein, and it is understood that the present application is not limited to the embodiments described herein and can be practiced with or without other apparatuses, systems, structures, methodologies, procedures, components, materials and so on. Therefore, the present application is not limited to the specific embodiments disclosed below, but instead has numerous applications and should not be limited to embodiments and implementations described and shown herein but should be construed to cover any alternatives falling within the scope of the present application.

[0053] In the description of the utility model, it is necessary to explain that the position relation or the position relation of the term "top, bottom" and the like indicated in the drawings is based on the position or the position relation shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and is not indicative or suggestive of the device or the element indicated must have a specific position, a specific position structure and operation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first, second, third, fourth, etc." are only for the purpose of description, and cannot be understood as indicative or suggestive of relative importance.

[0054] The utility model provides a cylinder for large capacity battery, wherein the large capacity battery is mainly the large capacity battery described in the background technology, and the specific structure can be referred to Chinese patent CN220797038U, the shell of the large capacity battery is usually composed of a cylinder with two open ends and an end plate sealed at the open end. Because the shell of such a large capacity battery has a large amount of free electrolyte, the sealing requirement of the shell is relatively high. Under this requirement, the utility model proposes to use the process of friction stir welding to weld two end plates at the opposite open ends of the cylinder, so as to ensure that the weld has high strength and sealing performance.

[0055] Of course, the large capacity battery therein can also be other large capacity batteries with high sealing requirements for the shell, and the shell of such a large capacity battery is composed of a cylinder with at least one open end (in such a cylinder, an electrolyte sharing chamber can not be provided) and an end plate sealed at the open end.

[0056] The cylinder in the utility model comprises a cylinder main body, the cylinder main body has at least one open end, and is used for realizing sealed welding in the mode of friction stir welding with the end plate; arc extinguishing is a key finishing step in friction stir welding, the utility model sets a rib as an arc collecting plate on the cylinder main body to simplify the operation process and improve production efficiency, and the step of cutting off the arc collecting plate after arc extinguishing is omitted; meanwhile, in the friction stir welding process, the positions of the tool feed point and the tool withdrawal point have a direct influence on the initial state and the termination state quality of the weld, the utility model makes the end face of the rib flush with the end face of the open end of the cylinder (i.e. located on the same plane), uses the end face of the rib as the tool feed point and the tool withdrawal point at the same time, can ensure the flatness of the tool feed point and the part to be welded, makes the stirring needle smoothly inserted, the end face of the rib tightly combined with the shaft shoulder to generate sufficient heat, makes the part to be welded uniformly mixed and form a continuous weld at the starting point, and improves the integrity of the weld. Meanwhile, the flatness of the tool withdrawal point and the part to be welded can also be ensured, the stirring needle is smoothly withdrawn, and the material at the end of the weld can be prevented from appearing shrinkage holes due to the sudden disappearance of the pressure of the stirring head. In addition, the tool feed point and the tool withdrawal point are located at the same point, which can ensure the continuity and stability of the welding path.

[0057] The utility model will be further described in combination with the drawings and specific embodiments.

[0058] Embodiment 1

[0059] As shown in Figure 2 and Figure 3 , they are the structure schematic diagram and sectional view of the cylinder 1 for large capacity battery in this embodiment; wherein the cylinder 1 includes a cylinder body 11 and a rib 12 fixed on the cylinder body 11.

[0060] The two ends of the cylinder body 11 are open ends, which are respectively used for sealing and fixing with two end plates 2; as can be seen from the drawings, in this embodiment, a stepped structure 116 is arranged on the end face of the open end of the cylinder body 11 along the circumferential direction, and the stepped face is used as the positioning face of the end plate 2. The stepped face provides a clear mounting position for the end plate 2, ensuring that the end plate 2 can be quickly and accurately aligned when assembling with the cylinder 1. The stepped face arranged along the circumferential direction of the cylinder body 11 can limit the end plate 2 from multiple directions, preventing the end plate 2 from shifting during installation, thereby ensuring the accuracy of the welding position. In addition, the stepped face can support and constrain the end plate 2 during welding, preventing the end plate 2 from deforming due to welding heat. This helps to maintain the flatness and dimensional accuracy of the end plate 2, ensuring that the structure after welding meets the design requirements.

[0061] As can be seen from Figure 2 and Figure 3 , in this embodiment, a plurality of pole post avoiding holes 115 are provided on the top plate 111 of the cylinder body, for the polarity terminals 31 of each single battery 3 in the large capacity battery to extend out. In this embodiment, the bottom plate 112 of the cylinder body is raised away from the top plate 111 of the cylinder body, forming a channel extending along the length direction as an electrolyte sharing chamber 113. In other embodiments, as shown in Figure 5 , two support ribs can also be provided on the bottom plate 112 of the cylinder body, and a channel is formed between the two support ribs as the electrolyte sharing chamber 113.

[0062] In this embodiment, the thickness of the cylinder body 11 is 6 cm, and in other embodiments, the thickness of the cylinder body 11 can be between 4 cm and 8 cm, within this range, the cylinder body 11 has a pressure bearing strength that meets the set requirements, while having a lower material cost.

[0063] As can be seen from Figure 2 and Figure 3 , the rib 12 in this embodiment extends along the length direction of the cylinder body 11 and is an integral part of the cylinder 1 (which can be formed by aluminum extrusion process), and the end faces of the two ends are flush with the two open ends of the cylinder body 11, respectively, as the feed point and retreat point when welding the two open ends.

[0064] In other embodiments, two ribs 12 can be employed, one rib 12 having one end face flush with one open end of the cylinder body 11, serving as the entry and exit point for welding of the open end; the other rib 12 having one end face flush with the other open end of the cylinder body 11, serving as the entry and exit point for welding of the open end; the two ribs 12 can be fixed to the cylinder body 11 by welding, bonding or other processes, but the process is more complex compared to the present embodiment.

[0065] The present embodiment employs an integrated structure, which is relatively simple in processing, and the rib 12 and the cylinder body 11 have the same material. In the welding process, the consistency of the thermal physical properties and chemical composition of the material is crucial to the quality of the welding. Since the rib 12 and the cylinder body 11 are integrated, there will be no welding defects caused by material differences. Finally, the rib 12 and the cylinder body 11 being an integrated piece allows the welding parameters to be more stably controlled. In traditional welding, the presence of the electrode holder may affect the stability of the welding arc and heat input, thus requiring adjustment of the welding parameters. The integrated design can eliminate this effect, allowing the welding parameters to remain stable throughout the welding process. This helps to improve the consistency of the weld quality and reduce the occurrence of welding defects.

[0066] As can be seen from Figure 3 , the rib 12 of the present embodiment is located between the cylinder body bottom plate 112 and the electrolyte sharing chamber outer side wall 114, without affecting the overall size of the cylinder body 11, so that the capacity density is not affected. In addition, when it is assembled into the energy storage container, the original energy storage container structure does not need to be changed; at the same time, it can also support the electrolyte sharing chamber outer side wall 114, helping to maintain the shape and stability of the electrolyte sharing chamber 113, and significantly enhancing the structural strength of the cylinder body 11.

[0067] In other embodiments, as shown in Figure 4 and Figure 5 , the rib 12 can be located on the outer side wall of the cylinder body 11, but compared to the present embodiment, the presence of the rib 12 increases the size of the cylinder body 11 in the width direction, reducing its energy density, and at the same time, it may be difficult to assemble it into the original energy storage container due to the presence of the rib 12.

[0068] In the present embodiment, the cross section of the rib 12 is rectangular, and the two edge lengths of the rectangular cross section can be defined as l1 and l2 respectively. In order to ensure that the end face of the rib 12 has sufficient area to accommodate the stirring pin, the two edge lengths are defined as follows in the present embodiment:

[0069] (d+2) cm ≤ l1 ≤ (d+8) cm, (d+2) cm ≤ l2 ≤ (d+8) cm, where d is the diameter of the stirring pin used for friction stir welding.

[0070] l1, l2≥(d+2)cm, that is, when the center of the stirring pin is located at the geometric center of the rib end face, it is required to reserve a safety distance of at least 1cm between the stirring pin and the edge of the rib 12. When the distance is too small, the stirring pin may be tilted when inserted into the end face of the rib 12, thereby reducing the quality of the entire weld; l1, l2≤(d+8)cm, that is, when the center of the stirring pin is located at the geometric center of the rib end face, it is required to reserve a distance of at most 4cm between the stirring pin and the edge of the rib 12. Of course, in other embodiments, the value can also be increased, but the relative material cost is higher, and at the same time, the weight of the cylinder body 11 is increased, thereby increasing the transportation cost.

[0071] Embodiment 2

[0072] The present embodiment is a large-capacity battery shell 5, which includes two end plates 2 and the cylinder 1 in Embodiment 1, and the structure is as shown in Figure 6 and Figure 7 The two end plates 2 are in abutment with the step surface of the open end step structure 116 of the cylinder body 11, and are respectively sealed and fixed at the two open ends of the cylinder body 11 by means of friction stir welding.

[0073] Embodiment 3

[0074] The present embodiment is a large-capacity battery, and the structure is as shown in Figure 8 and Figure 9 The present embodiment is a large-capacity battery, and the structure is as shown in

[0075] The single battery 3 in the present embodiment is a square shell battery, and the number is 12. The inner cavity of each single battery 3 includes an electrolyte area and a gas area. In other embodiments, the number of single batteries 3 can be adjusted according to actual needs, and the form of the single battery 3 can also be adjusted according to actual needs. The electrolyte areas of the inner cavities of the single batteries 3 are connected through the electrolyte sharing chamber 113.

[0076] The polarity terminal 31 of each single battery 3 extends out of the corresponding avoiding hole 115 on the cylinder body top plate 111, and a sealing connecting piece is additionally arranged between the avoiding hole 115 and the polarity terminal 31, so as to realize the fixed sealing of the area of the cylinder body top plate 111 corresponding to the avoiding hole 115 and the shell of the single battery 3.

[0077] It should be noted that the polarity terminal 31 of the single battery 3 described herein can be a single battery 3 pole, and if the single battery 3 pole cannot smoothly extend out of the avoiding hole 115 or the height of the single battery 3 pole extending out of the avoiding hole 115 does not meet the set requirements, a pole adapter can also be connected to the single battery 3 pole, and the overall structure of the single battery 3 pole and the pole adapter in cooperation can be used as the single battery 3 polarity terminal 31.

[0078] In order to improve the heat exchange efficiency of the large capacity battery, the embodiment further comprises a heat transfer pipe 4, which is fixed on the position where the polarity terminal 31 of each single battery 3 extends out of the avoiding hole 115. When the temperature of the large capacity battery is higher than the set threshold value, the large capacity battery is cooled by passing a heat exchange medium with lower temperature into the heat transfer pipe 4; when the temperature of the large capacity battery is lower than the set threshold value, the large capacity battery is heated by passing a heat exchange medium with higher temperature into the heat transfer pipe 4; by controlling the temperature of the heat exchange medium, it can be ensured that the large capacity battery always operates at a normal working temperature.

Claims

1. A can for a high-capacity battery, characterized by: The cylinder body has at least one open end. The cylinder body has at least one open end. The end face of the rib is in the same plane as the end face of the open end of the cylinder, serving as the entry point and exit point of the friction stir welding.

2. The can for a large capacity battery according to claim 1, characterized by: The cylinder body has two opposite open ends; the rib is one, extending along the length direction of the cylinder body and being an integral part of the cylinder body.

3. The can for a high-capacity battery according to claim 2, characterized by: The bottom plate of the cylinder body is convex in the direction away from the top plate, forming an electrolyte sharing chamber; the rib is located between the bottom plate of the cylinder body and the outer lateral wall of the electrolyte sharing chamber.

4. The can for a high-capacity battery according to claim 3, characterized by: The cross section of the rib is rectangular, and the length of the cross section of the rib is l1 and l2, respectively, (d+2) cm≤l1≤(d+8) cm, (d+2) cm≤l2≤(d+8) cm, wherein d is the diameter of the stirring needle used for friction stir welding.

5. The can for a high-capacity battery according to any one of claims 1 to 4, characterized by: A step structure is arranged along the end face of the open end of the cylinder body in the circumferential direction.

6. The can for a high-capacity battery according to any one of claims 1 to 4, characterized by: The wall thickness of the cylinder body is h, wherein 4 cm≤h≤8 cm.

7. A housing for a high capacity battery, characterized by: The cylinder body includes an end plate and the cylinder body of any one of claims 1-6; the end plate is sealed and fixed to the open end of the cylinder body by friction stir welding.

8. The case for a large capacity battery according to claim 7, wherein: The end plate abuts against the step face of the step structure of the open end of the cylinder body.

9. A high capacity battery characterized by: The battery includes an outer shell and n single batteries arranged in the same direction in the outer shell; the outer shell is the outer shell of the large-capacity battery of claim 7 or 8, and n is an integer greater than 1.

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