Rectangular battery and manufacturing method thereof

Abstract

The square battery comprises a shell and a battery cell arranged in the shell, the shell comprises a top cover plate, a positive pole is arranged on the top cover plate, the positive pole and the top cover plate are insulated, the battery cell comprises a positive pole lug group and a negative pole lug group, and the positive pole lug group and the negative pole lug group are both located at the end, facing the top cover plate, of the battery cell. The positive pole lug group is gathered towards the first side of the battery cell and forms a first bending structure which is arranged corresponding to the positive pole and is bent once, and the negative pole lug group is gathered towards the first side of the battery cell and forms a second bending structure which is arranged corresponding to the top cover plate and is bent once; the positive pole lug group is directly welded and connected with the positive pole column, or the positive pole lug group is welded and connected with the positive pole column through a plate-shaped first adapter plate; and the negative tab group is directly welded and connected with the top cover plate, or the negative tab group is welded and connected with the top cover plate through a plate-shaped second adapter plate. According to the embodiment of the invention, the space utilization rate in the battery is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more particularly to a square battery and a method for manufacturing the same. Background Technology

[0002] In some existing metal-cased batteries, the terminals are typically riveted to the casing. To ensure the laser welding path of the adapter plate is not obstructed, the adapter plate is usually quite long to ensure that the path is not blocked when the stacked core (wound core) moves away from the laser-welded adapter plate. When the stacked core (wound core) is flipped into the casing, the adapter plate and the tab group need to be bent simultaneously. A long adapter plate is also needed to ensure that the stacked core (wound core) does not interfere with the casing or pull on the tabs during insertion. After insertion into the casing, the two bends of the adapter plate and the tab group occupy a significant amount of internal space in the battery, resulting in reduced space utilization within the cell. Summary of the Invention

[0003] The purpose of this invention is to provide a square battery and its manufacturing method to solve the problem of reduced space utilization inside the battery cell caused by the two bends of the adapter plate and the tab group in the prior art.

[0004] To achieve the above objectives, the present invention provides a square battery, comprising a casing and a battery cell disposed within the casing. The casing includes a top cover plate, on which a positive electrode post is provided. The positive electrode post is insulated from the top cover plate. The battery cell includes a group of positive electrode tabs and a group of negative electrode tabs, both located at one end of the battery cell facing the top cover plate. The positive electrode tabs converge toward a first side of the battery cell to form a first bending structure corresponding to a first bend of the positive electrode post. The negative electrode tabs converge toward the first side of the battery cell to form a second bending structure corresponding to a first bend of the top cover plate. The positive electrode tabs are directly welded to the positive electrode post, or the positive electrode tabs are welded to the positive electrode post via a plate-shaped first adapter piece. The negative electrode tabs are directly welded to the top cover plate, or the negative electrode tabs are welded to the top cover plate via a plate-shaped second adapter piece.

[0005] Preferably, the housing further includes a shell and a side cover plate. The shell includes a bottom plate and a connecting side plate disposed on the bottom plate to form a first cavity corresponding to the top cover plate and a second cavity corresponding to the side cover plate. The top cover plate is disposed on the shell to close the first cavity, and the side cover plate is disposed on the shell and the top cover plate to close the second cavity.

[0006] Preferably, the housing is a one-piece structure.

[0007] Preferably, the first bending structure has a first bending area, which is located close to the base plate and the distance between the first bending area and the base plate is greater than or equal to 0 and less than or equal to 3 mm.

[0008] Preferably, the second bending structure has a second bending region, which is located close to the base plate and the distance between the second bending region and the base plate is greater than or equal to 0 and less than or equal to 3 mm.

[0009] Preferably, the length of the housing is greater than or equal to 10 mm and less than or equal to 40 mm, the width of the housing is greater than or equal to 10 mm and less than or equal to 30 mm, and the height of the housing is greater than or equal to 3 mm and less than or equal to 6 mm.

[0010] Preferably, the top cover, the side cover, and the housing are all metal structures.

[0011] This invention also provides a method for manufacturing a square battery, comprising the following steps: placing a top cover plate flat with the welding surface of the top cover plate and the welding surface of the positive electrode post facing upwards; gathering the positive electrode tabs of the battery cell towards a first side of the battery cell, and placing the free ends of the positive electrode tabs on the positive electrode post or a first adapter piece on the positive electrode post; gathering the negative electrode tabs of the battery cell towards the first side of the battery cell, and placing the free ends of the negative electrode tabs on the top cover plate or a second adapter piece on the top cover plate; welding the positive electrode tabs to the positive electrode post, or welding the positive electrode tabs to the first adapter piece; welding the negative electrode tabs to the top cover plate, or welding the negative electrode tabs to the second adapter piece; bending the welded positive electrode tabs once to form a first bent structure, and bending the welded negative electrode tabs once to form a second bent structure.

[0012] Preferably, the housing further includes a shell and side cover plates. The shell includes a bottom plate and connecting side plates surrounding the bottom plate to form a first cavity corresponding to the top cover plate and a second cavity corresponding to the side cover plate. After the steps of bending the welded positive electrode tab group to form the first bending structure and bending the welded negative electrode tab group to form the second bending structure, the method further includes: placing the battery cell in the shell and covering the shell with the top cover plate; welding the top cover plate to the shell to close the first cavity; covering the shell and the top cover plate with the side cover plate; and welding the side cover plate, the top cover plate, and the shell together to close the second cavity.

[0013] Preferably, the housing, the top cover plate, or the side cover plate has an injection hole that communicates with the interior of the housing. After the step of welding the side cover plate, the top cover plate, and the housing together to close the second cavity, the method further includes: injecting electrolyte into the housing through the injection hole and sealing the injection hole with a sealing nail.

[0014] Compared with the prior art, the present invention has only one first bending structure between the positive electrode post and the positive electrode tab group and only one second bending structure between the top cover plate and the negative electrode tab group. Compared with the two bending structures in the prior art, the embodiment of the present invention greatly improves the internal space utilization of the battery, thereby improving the energy density of the battery. Attached Figure Description

[0015] Figure 1 This is a structural diagram of a square battery according to an embodiment of the present invention.

[0016] Figure 2 This is an exploded structural diagram of the outer shell in an embodiment of the present invention.

[0017] Figure 3 This is a structural diagram of the positive electrode group and negative electrode group of the battery cell being welded to the first adapter piece and the second adapter piece, respectively, in one embodiment of the present invention.

[0018] Figure 4 This is a structural diagram of an embodiment of the present invention after a first bending structure and a second bending structure are formed between the top cover plate and the battery cell.

[0019] Figure 5 In one embodiment of the present invention, Figure 4 The diagram shows the structure of the top cover, battery cell, and casing after assembly.

[0020] Figure 6 for Figure 5 A cross-sectional structural diagram.

[0021] Figure 7 for Figure 5 Another cross-sectional view of the structure.

[0022] Figure 8 This is a structural diagram of the top cover plate and the battery cell after the first bending structure and the second bending structure are formed in another embodiment of the present invention. In this case, the first adapter piece and the second adapter piece are not provided.

[0023] Figure 9 In another embodiment of the present invention, Figure 8 The diagram shows the structure of the top cover, battery cell, and casing after assembly.

[0024] Explanation of reference numerals in the attached figures: 10. Square battery; 1. Outer casing; 11. Top cover plate; 12. Casing; 120. Receiving cavity; 121. Bottom plate; 122. First side plate; 123. Second side plate; 124. Third side plate; 125. First cavity opening; 126. Second cavity opening; 127. Liquid filling hole; 13. Side cover plate; 2. Cell; 201. First side; 202. Second side; 21. Positive electrode tab group; 211. First bending structure; 2111. First bending area; 22. Negative electrode tab group; 221. Second bending structure; 2211. Second bending area; 3. Positive electrode post; 4. Insulator; 5. First adapter piece; 6. Second adapter piece. Detailed Implementation

[0025] To illustrate the technical content, structural features, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0026] Example 1 like Figures 1 to 9 As shown, this embodiment of the invention discloses a square battery, including a casing 1 and a battery cell 2 disposed within the casing 1. The casing 1 includes a top cover plate 11, on which a positive electrode post 3 is provided. The positive electrode post 3 is insulated from the top cover plate 11. The battery cell 2 includes a positive electrode tab group 21 and a negative electrode tab group 22. Both the positive electrode tab group 21 and the negative electrode tab group 22 are located at the end of the battery cell 2 facing the top cover plate 11. The positive electrode tab group 21 converges towards a first side 201 of the battery cell 2 to form a first bending structure 211 corresponding to the first bending of the positive electrode post 3. The negative electrode tab group 22 converges towards the first side 201 of the battery cell 2 to form a second bending structure 221 corresponding to the first bending of the top cover plate 11. The positive electrode tab group 21 and the positive electrode post 3 are welded together by a plate-shaped first adapter piece 5. The negative electrode tab group 22 and the top cover plate 11 are welded together by a plate-shaped second adapter piece 6. Specifically, as shown... Figures 1 to 7 As shown, the battery cell 2 can be a stacked battery cell or a wound battery cell. The battery cell 2 has a first side 201 and a second side 202 in the thickness direction. The first bending structure 211 and the second bending structure 221 can both be C-shaped. The positive electrode tab group 21 and the negative electrode tab group 22 are arranged alternately to ensure electrical isolation between the positive electrode tab group 21 and the negative electrode tab group 22. The positive electrode post 3 passes through the top cover plate 11 and is connected to the top cover plate 11 by an insulating member 4 to ensure insulation between the positive electrode post 3 and the top cover plate 11. The insulating member 4 can be formed by combining multiple sealing rings. The connection method between the positive electrode post 3 and the top cover plate 11 is prior art and will not be described in detail here. The surface of the positive electrode post 3 facing the battery cell 2 is a plane for welding the first adapter piece 5 or, in other specific embodiments, for welding with the positive electrode tab group 21, such as... Figure 2 as well as Figures 5 to 6As shown, the inner surface of the positive electrode post 3 can be parallel to the side of the top cover plate 11 facing the cell 2. Therefore, in this embodiment of the invention, both the first adapter piece 5 and the second adapter piece 6 are plate-shaped. The first adapter piece 5 and the second adapter piece 6 do not need to be bent, and the dimensions of the first adapter piece 5 and the second adapter piece 6 can be set to be relatively short. Therefore, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22, which greatly improves the space utilization rate inside the square battery 10. In addition, the first adapter piece 5 and the second adapter piece 6 are both plate-shaped with a simple appearance, and the first adapter piece 5 and the second adapter piece 6 do not need to be bent, which can ensure that the positive electrode tab group 21 and the negative electrode tab group 22 are not pulled and broken during the bending process.

[0027] It should be noted that the welding connection in the embodiments of the present invention is preferably a laser welding connection, but it is not limited thereto.

[0028] In some other specific embodiments of the invention, such as Figures 8 to 9 As shown, the first adapter piece 5 and the second adapter piece 6 can be eliminated. That is, the positive electrode tab group 21 is directly welded to the positive electrode post 3, and the negative electrode tab group 22 is directly welded to the top cover plate 11. This results in only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. This also greatly improves the space utilization rate inside the square battery 10, and the structure is simpler.

[0029] In some other specific embodiments of the invention, only the first adapter piece 5 may be provided, without the second adapter piece 6. That is, the positive electrode tab group 21 and the positive electrode post 3 are welded together by the plate-shaped first adapter piece 5, and the negative electrode tab group 22 is directly welded together with the top cover plate 11. Alternatively, only the second adapter piece 6 may be provided, without the first adapter piece 5. That is, the positive electrode tab group 21 and the positive electrode post 3 are directly welded together, and the negative electrode tab group 22 and the top cover plate 11 are welded together by the plate-shaped second adapter piece 6. This also allows for only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. This can greatly improve the space utilization rate inside the square battery 10, and the structure is also simpler compared to the case where both the first adapter piece 5 and the second adapter piece 6 are used.

[0030] In this embodiment of the invention, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. Compared with the two bending structures in the prior art, this embodiment of the invention greatly improves the space utilization rate inside the battery, thereby improving the energy density of the battery.

[0031] In embodiments of the present invention, such as Figures 1 to 2 As shown, the outer casing 1 also includes a housing 12 and a side cover plate 13. The housing 12 includes a bottom plate 121 and a connecting side plate disposed on the bottom plate 121 so that the housing 12 forms a first cavity 125 corresponding to the top cover plate 11 and a second cavity 126 corresponding to the side cover plate 13. The top cover plate 11 covers the housing 12 and closes the first cavity 125, and the side cover plate 13 covers the housing 12 and the top cover plate 11 and closes the second cavity 126. Specifically, a receiving cavity 120 for placing the battery cell 2 is formed inside the housing 12. The bottom plate 121 is rectangular, and connecting side plates are provided on three of the four sides of the bottom plate 121. The connecting side plates include a first side plate 122, a second side plate 123, and a third side plate 124. The first side plate 122 and the third side plate 124 are arranged opposite to each other. The second side plate 123 connects the first side plate 122 and the third side plate 124. The first side plate 122, the third side plate 124, and the bottom plate 121 form a first cavity 125. The first side plate 122, the second side plate 123, and the third side plate 124 form a first cavity 125. The first side plate 122 and the third side plate 124 form a second cavity 126. A top cover plate 11 is placed on the first side plate 122, the third side plate 124, and the bottom plate 121 and welded to them. A side cover plate 13 is placed on the first side plate 122, the second side plate 123, the third side plate 124, and the top cover plate 11 and welded to them, thereby sealing the first cavity 125 and the second cavity 126. The housing 12 may also have a liquid injection hole 127 communicating with the interior of the outer shell 1, such as... Figure 2 As shown, the injection hole 127 can be opened on the first side plate 122. Of course, the injection hole 127 can also be opened on the third side plate 124, or the injection hole 127 can also be opened on the top cover plate 11 or the side cover plate 13. After the injection hole 127 is filled with liquid, it will be sealed by the sealing nail, so that the outer shell 1 forms a sealed structure.

[0032] In this embodiment of the invention, the housing 12 is a one-piece structure. Specifically, as shown... Figure 2 As shown, the housing 12 can be integrally stamped from a single piece of material, which facilitates the processing of the housing 12 and provides better sealing. Of course, the housing 12 can also be formed in other ways, as long as the forming method meets the sealing requirements of the square battery 10.

[0033] In this embodiment of the invention, the first bending structure 211 has a first bending region 2111, which is located close to the base plate 121, and the distance between the first bending region 2111 and the base plate 121 is greater than or equal to 0 and less than or equal to 3 mm. Specifically, as shown... Figures 5 to 6As shown, the first bending area 2111 is set close to the base plate 121 and the distance between the first bending area 2111 and the base plate 121 is the first distance d1. By setting the first distance d1, when the cell 2 is put into the housing 12, when the first distance d1 is greater than 0, the first bending area 2111 does not contact the base plate 121, thus avoiding the impact on the first bending structure 211. When the first distance d1 is equal to 0, although the first bending area 2111 contacts the base plate 121, it will not be squeezed by the base plate 121, thus also avoiding the impact on the first bending structure 211. Moreover, the first bending area 2111 is set close to the base plate 121, which further ensures that the positive electrode tab group 21 will not split.

[0034] Furthermore, the second bending structure 221 has a second bending region 2211, which is located close to the base plate 121, and the distance between the second bending region 2211 and the base plate 121 is greater than or equal to 0 and less than or equal to 3 mm. Specifically, as shown... Figure 5 as well as Figure 7 As shown, the second bending region 2211 is located close to the base plate 121, and the distance between the second bending region 2211 and the base plate 121 is the second distance d2. By setting the second distance d2, when the cell 2 is placed into the housing 12, when the second distance d2 is greater than 0, the second bending region 2211 does not contact the base plate 121, thus avoiding any impact on the second bending structure 221. When the second distance d2 is equal to 0, although the second bending region 2211 contacts the base plate 121, it will not be squeezed by the base plate 121, thus also avoiding any impact on the second bending structure 221. Moreover, the second bending region 2211 is located close to the base plate 121, further ensuring that the negative electrode tab group 22 will not split.

[0035] In embodiments of the present invention, such as Figures 1 to 2 As shown, the length of the outer shell 1 is greater than or equal to 10 mm and less than or equal to 40 mm, the width of the outer shell 1 is greater than or equal to 10 mm and less than or equal to 30 mm, and the height of the outer shell 1 is greater than or equal to 3 mm and less than or equal to 6 mm. Specifically, the length direction of the outer shell 1 corresponds to the length direction of the first side 12, and the height direction of the outer shell 1 corresponds to the height direction of the first side 12. The square battery 10 in this embodiment of the invention is small in size and suitable for use in wearable devices.

[0036] In this embodiment of the invention, the top cover plate 11, the side cover plate 13 and the shell 12 are all metal structures, for example, the top cover plate 11, the side cover plate 13 and the shell 12 are all made of steel or aluminum.

[0037] Example 2 This invention also provides a method for manufacturing a square battery, used to manufacture the square battery 10 provided with the first adapter piece 5 and the second adapter piece 6, the manufacturing method including the following steps: S1. Place the top cover plate 11 flat with the welding surface of the top cover plate 11 and the welding surface of the positive electrode post 3 facing upwards; specifically, as follows: Figure 3 As shown, the top cover plate 11 is an independently set component. Therefore, the top cover plate 11 can be placed flat, which facilitates the welding of the first adapter piece 5 on the positive electrode post 3 and the welding of the second adapter piece 6 on the top cover plate 11 in step S2. It also facilitates the welding connection of the positive electrode tab group 21 to the first adapter piece 5 in step S5 and the welding connection of the negative electrode tab group 22 to the second adapter piece 6 in step S6.

[0038] S2. Weld the first adapter piece 5 onto the positive electrode post 3 and the second adapter piece 6 onto the top cover plate 11. Specifically, the first adapter piece 5 can be welded onto the positive electrode post 3 by laser welding process, and the second adapter piece 6 can be welded onto the top cover plate 11 by laser welding process.

[0039] S3. Gather the positive electrode tab group 21 of the battery cell 2 towards the first side 201 of the battery cell 2, and place the free end of the positive electrode tab group 21 on the first adapter piece 5 on the positive electrode post 3; specifically, as follows: Figure 3 As shown, the battery cell 2 is placed flat, so that the free end of the positive electrode tab group 21 can be directly connected to the first adapter piece 5.

[0040] S4. Gather the negative electrode tabs 22 of the battery cell 2 towards the first side 201 of the battery cell 2, and place the free end of the negative electrode tabs 22 on the second adapter piece 6 on the top cover plate 11; specifically, as follows: Figure 3 As shown, the battery cell 2 is placed flat, so that the free end of the negative electrode tab group 22 can be directly connected to the second adapter piece 6.

[0041] S5. Weld the positive electrode tab group 21 to the first adapter piece 5; specifically, as follows: Figure 3 As shown, when laser welding is used, the parts of the cell 2 other than the positive electrode tab group 21 used for welding with the first adapter piece 5 and the negative electrode tab group 22 used for welding with the second adapter piece 6 will not interfere with the laser path with the top cover plate 11. Therefore, the positive electrode tab group 21 can be directly welded to the first adapter piece 5 from above using a laser.

[0042] S6. Weld the negative electrode tab group 22 to the second adapter piece 6. Similarly, when laser welding is used, the parts of the cell 2 other than the positive electrode tab group 21 used to weld to the first adapter piece 5 and the negative electrode tab group 22 used to weld to the second adapter piece 6 will not interfere with the laser path with the top cover plate 11, so that the negative electrode tab group 22 can be directly welded to the second adapter piece 6 from above using a laser.

[0043] S7. The welded positive electrode tab group 21 is bent once to form a first bent structure 211, and the welded negative electrode tab group 22 is bent once to form a second bent structure 221, as detailed below. Figure 3 as well as Figure 4 As shown.

[0044] It should be noted that step S5 can be interchanged with step S4. That is, after placing the free end of the positive electrode tab group 21 on the first adapter piece 5 on the positive electrode post 3, the positive electrode tab group 21 and the first adapter piece 5 can be welded directly.

[0045] In this embodiment of the invention, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. Under the same internal dimensions, the space occupied by the positive electrode tab group 21, the negative electrode tab group 22, the first adapter piece 5 and the second adapter piece 6 in the length direction of the casing 12 is reduced by 30% to 60% compared with the space occupied by the traditional square battery with two bends. This can increase the length of the electrode in the cell 2 to improve the spatial energy density of the battery.

[0046] In this embodiment of the invention, the first bending structure 211 has a first bending region 2111, which is located close to the base plate 121 and the distance between the first bending region 2111 and the base plate 121 is greater than or equal to 0 and less than or equal to 3 mm; the second bending structure 221 has a second bending region 2211, which is located close to the base plate 121 and the distance between the second bending region 2211 and the base plate 121 is greater than or equal to 0 and less than or equal to 3 mm. Specifically, as shown... Figures 5 to 6As shown, the first bending region 2111 is positioned close to the base plate 121, and the distance between the first bending region 2111 and the base plate 121 is a first distance d1. By setting the first distance d1, when the battery cell 2 is placed into the housing 12, if the first distance d1 is greater than 0, the first bending region 2111 does not contact the base plate 121, thus avoiding any impact on the first bending structure 211. If the first distance d1 is equal to 0, although the first bending region 2111 contacts the base plate 121, it will not be squeezed by the base plate 121, also avoiding any impact on the first bending structure 211. Furthermore, the fact that the first bending region 2111 is positioned close to the base plate 121 further ensures that the positive electrode tab group 21 will not split. Figure 5 as well as Figure 7 As shown, the second bending region 2211 is located close to the base plate 121, and the distance between the second bending region 2211 and the base plate 121 is the second distance d2. By setting the second distance d2, when the battery cell 2 is placed into the housing 12, when the second distance d2 is greater than 0, the second bending region 2211 does not contact the base plate 121, thus avoiding any impact on the second bending structure 221. When the second distance d2 is equal to 0, although the second bending region 2211 contacts the base plate 121, it will not be squeezed by the base plate 121, thus also avoiding any impact on the second bending structure 221. Moreover, the second bending region 2211 is located close to the base plate 121, further ensuring that the negative electrode tab group 22 will not split. In addition, the positive electrode tab group 21 and the negative electrode tab group 22 have already undergone the first bending structure 211 and the second bending structure 221 before being placed in the housing 12. The battery cell 2 will not interfere with other structural components during the process of entering the housing, making installation convenient and without affecting the battery cell 2.

[0047] In this embodiment of the invention, the outer shell 1 further includes a shell 12 and a side cover plate 13. The shell 12 includes a bottom plate 121 and a connecting side plate surrounding the bottom plate 121 to form a first cavity 125 corresponding to the top cover plate 11 and a second cavity 126 corresponding to the side cover plate 13. After step S7, which involves bending the welded positive electrode tab group 21 to form a first bending structure 211 and bending the welded negative electrode tab group 22 to form a second bending structure 221, the invention further includes: S81. Place the battery cell 2 into the housing 12 and cover the housing 12 with the top cover plate 11. Specifically, as follows: Figure 5 As shown, after the battery cell 2 is placed in the housing 12, the top cover plate 11 can be correspondingly placed on the housing 12.

[0048] S82. The top cover plate 11 and the housing 12 are welded together to seal the first cavity 125. Specifically, the top cover plate 11 and the housing 12 can be welded together using laser welding technology.

[0049] S83. Cover the housing 12 and the top cover 11 with the side cover 13.

[0050] S84. The side cover plate 13, the top cover plate 11, and the housing 12 are welded together to seal the second cavity 126. Specifically, as follows: Figure 1 as well as Figure 5 As shown, the side cover plate 13, top cover plate 11 and shell 12 can be welded together using laser welding technology to form a shell 12 that is sealed except for the injection hole 127.

[0051] In this embodiment of the invention, the housing 12, the top cover plate 11, or the side cover plate 13 are provided with a liquid injection hole 127 communicating with the interior of the housing 1. After step S84, which involves welding the side cover plate 13, the top cover plate 11, and the housing 12 together to seal the second cavity 126, the method further includes: S9. Electrolyte is injected into the outer casing 1 through the injection hole 127, and the injection hole 127 is sealed with a sealing pin. Specifically, the sealing pin can be welded to the outer casing 1. The method of connecting the sealing pin to the outer casing 1 is existing technology and will not be described in detail here.

[0052] In the manufacturing method of the square battery in this embodiment of the invention, since the top cover plate 11 is set independently, it can be laid flat, thus avoiding interference with the laser welding optical path. Therefore, this invention can utilize ultra-short plate-shaped first adapter piece 5 and second adapter piece 6, eliminating the need to bend the first adapter piece 5 and second adapter piece 6. Only the first bending structure 211 and the second bending structure 221 are used, resulting in a simple bending structure with a small space occupation. This ensures that the positive electrode tab group 21 and the negative electrode tab group 22 are not pulled and broken during the bending process, and also improves the internal space utilization of the battery, thereby increasing the battery energy density.

[0053] Example 3 The difference between this embodiment and Embodiment 2 is that the first adapter piece 5 and the second adapter piece 6 are omitted. That is, the positive electrode tab group 21 is directly welded to the positive electrode post 3, and the negative electrode tab group 22 is directly welded to the top cover plate 11. Therefore, the manufacturing method of the square battery in this embodiment is used to manufacture the square battery 10 without the first adapter piece 5 and the second adapter piece 6, and includes the following steps: S10. Place the top cover plate 11 flat and make the welding surface of the top cover plate 11 and the welding surface of the positive electrode post 3 face upward; specifically, the top cover plate 11 is an independently set component, so the top cover plate 11 can be placed flat to facilitate the welding connection between the positive electrode tab group 21 and the positive electrode post 3 in step S40 and the welding connection between the negative electrode tab group 22 and the negative electrode post 3 in step S50.

[0054] S20. Gather the positive electrode tab group 21 of the battery cell 2 toward the first side 201 of the battery cell 2, and place the free end of the positive electrode tab group 21 on the positive electrode post 3; specifically, the battery cell 2 is placed flat so that the free end of the positive electrode tab group 21 can be directly connected to the positive electrode post 3.

[0055] S30. Gather the negative electrode tab group 22 of the battery cell 2 toward the first side 201 of the battery cell 2, and place the free end of the negative electrode tab group 22 on the top cover plate 11; specifically, the battery cell 2 is placed flat so that the free end of the negative electrode tab group 22 can be directly connected to the top cover plate 11.

[0056] S40. Weld the positive electrode tab group 21 to the positive electrode post 3. Specifically, when laser welding is used, the part of the cell 2 other than the part of the positive electrode tab group 21 used to weld to the positive electrode post 3 and the part of the negative electrode tab group 22 used to weld to the top cover plate 11 will not interfere with the laser path with the top cover plate 11, so that the positive electrode tab group 21 can be directly welded to the positive electrode post 3 from above using laser.

[0057] S50. The negative electrode tab group 22 is welded to the top cover plate 11. Similarly, when laser welding is used, the part of the cell 2 other than the part of the positive electrode tab group 21 used to weld to the positive electrode post 3 and the part of the negative electrode tab group 22 used to weld to the top cover plate 11 will not interfere with the laser path with the top cover plate 11, so the negative electrode tab group 22 can be directly welded to the top cover plate 11 from above using laser.

[0058] S60. The welded positive electrode tab group is bent once to form a first bent structure 211, and the welded negative electrode tab group 22 is bent once to form a second bent structure 221, specifically as follows: Figure 8 As shown.

[0059] It should be noted that step S40 can be interchanged with step S30, that is, after placing the free end of the positive electrode tab group 21 on the positive electrode post 3, the positive electrode tab group 21 and the positive electrode post 3 can be welded directly.

[0060] In this embodiment of the invention, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. Under the same internal dimensions, the space occupied by the positive electrode tab group 21 and the negative electrode tab group 22 in the length direction of the casing 12 of the square battery 10 is reduced by 30% to 60% compared with the space occupied by the traditional square battery with two bends, thereby increasing the length of the electrode in the cell 2 to improve the spatial energy density of the battery.

[0061] In this embodiment of the invention, the outer shell 1 further includes a shell 12 and a side cover plate 13. The shell 12 includes a bottom plate 121 and a connecting side plate surrounding the bottom plate 121 to form a first cavity 125 corresponding to the top cover plate 11 and a second cavity 126 corresponding to the side cover plate 13. After step S60, which involves bending the welded positive electrode tab group to form a first bending structure 211 and bending the welded negative electrode tab group 22 to form a second bending structure 221, the invention further includes: S701. Place the battery cell 2 into the housing 12 and cover the housing 12 with the top cover plate 11. Specifically, as follows: Figure 9 As shown, after the battery cell 2 is placed in the housing 12, the top cover plate 11 can be correspondingly placed on the housing 12.

[0062] S702. The top cover plate 11 and the housing 12 are welded together to seal the first cavity 125. Specifically, the top cover plate 11 and the housing 12 can be welded together using laser welding technology.

[0063] S703. The side cover plate 13 is placed on the housing 12 and the top cover plate 11.

[0064] S704. The side cover plate 13, top cover plate 11, and housing 12 are welded together to seal the second cavity 126. Specifically, as follows: Figure 1 as well as Figure 9 As shown, the side cover plate 13, top cover plate 11 and shell 12 can be welded together using laser welding technology, thereby forming a shell 12 that is sealed except for the area where the injection hole 127 is connected to the outside.

[0065] In this embodiment of the invention, the housing 12, top cover plate 11, or side cover plate 13 are provided with a liquid injection hole 127 communicating with the interior of the housing 1. After step S704, which involves welding the side cover plate 13, top cover plate 11, and housing 12 together to seal the second cavity 126, the method further includes: S80. Electrolyte is injected into the outer casing 1 through the injection hole 127, and the injection hole 127 is sealed with a sealing pin. Specifically, the sealing pin can be welded to the outer casing 1. The method of connecting the sealing pin to the outer casing 1 is existing technology and will not be described in detail here.

[0066] In the manufacturing method of the square battery in this embodiment of the invention, since the top cover plate 11 is set independently, it can be laid flat, thus avoiding interference with the laser welding optical path. Therefore, this invention can directly weld the positive electrode tab group 21 to the positive electrode post 3 and the negative electrode tab group 22 to the top cover plate 11, eliminating the need for the first adapter piece 5 and the second adapter piece 6. This results in a simpler structure and further saves on processes. In addition, with only the first bending structure 211 and the second bending structure 221, the bending morphology is simple and occupies little space. This ensures that the positive electrode tab group 21 and the negative electrode tab group 22 are not pulled and broken during bending, and also improves the internal space utilization of the battery, thereby increasing the battery energy density.

[0067] Example 4 The difference between this embodiment and embodiment two is that only the first adapter piece 5 is provided, and the second adapter piece 6 is not provided. That is, the positive electrode tab group 21 and the positive electrode post 3 are welded together through the first adapter piece 5, and the negative electrode tab group 22 is directly welded together with the top cover plate 11. Therefore, the manufacturing method of the square battery 10 in this embodiment is used to manufacture the square battery 10 with only the first adapter piece 5, and includes the following steps: S100. Place the top cover plate 11 flat with the welding surface of the top cover plate 11 and the welding surface of the positive electrode post 3 facing upwards. Specifically, the top cover plate 11 is an independently set component. Therefore, the top cover plate 11 can be laid flat to facilitate the welding of the first adapter piece 5 on the positive electrode post 3 in step S200, and to facilitate the welding connection of the positive electrode tab group 21 to the first adapter piece 5 in step S500 and the welding connection of the negative electrode tab group 22 to the second adapter piece 6 in step S600.

[0068] S200. Weld the first adapter piece 5 onto the positive terminal 3. Specifically, the first adapter piece 5 can be welded onto the positive terminal 3 using a laser welding process.

[0069] S300, gather the positive electrode tab group 21 of the battery cell 2 toward the first side 201 of the battery cell 2, and place the free end of the positive electrode tab group 21 on the first adapter piece 5 on the positive electrode post 3; specifically, the battery cell 2 is placed flat so that the free end of the positive electrode tab group 21 can be directly connected to the first adapter piece 5.

[0070] S400, gather the negative electrode tab group 22 of the battery cell 2 toward the first side 201 of the battery cell 2, and place the free end of the negative electrode tab group 22 on the top cover plate 11; specifically, the battery cell 2 is placed flat so that the free end of the negative electrode tab group 22 can be directly connected to the top cover plate 11.

[0071] S500, The positive electrode tab group 21 is welded to the first adapter piece 5; specifically, when laser welding is used, the part of the cell 2 other than the part of the positive electrode tab group 21 used to weld to the first adapter piece 5 and the part of the negative electrode tab group 22 used to weld to the top cover plate 11 will not interfere with the laser path with the top cover plate 11, so that the positive electrode tab group 21 can be directly welded to the first adapter piece 5 from above using laser.

[0072] S600, the negative electrode tab group 22 is welded to the top cover plate 11; similarly, when laser welding is used, the part of the positive electrode tab group 21 used to weld to the first adapter piece 5 and the part of the negative electrode tab group 22 used to weld to the top cover plate 11 will not interfere with the laser path with the top cover plate 11, so the negative electrode tab group 22 can be directly welded to the top cover plate 11 from above using laser.

[0073] S700, the welded positive electrode tab group is bent once to form a first bent structure 211, and the welded negative electrode tab group 22 is bent once to form a second bent structure 221.

[0074] It should be noted that step S500 can be interchanged with step S400. That is, after placing the free end of the positive electrode tab group 21 on the first adapter piece 5 on the positive electrode post 3, the positive electrode tab group 21 and the first adapter piece 5 can be directly welded together.

[0075] In this embodiment of the invention, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. Under the same internal dimensions, the space occupied by the positive electrode tab group 21, the negative electrode tab group 22, and the first adapter piece 5 in the length direction of the housing 12 is reduced by 30% to 60% compared with the space occupied by the traditional square battery 10 with two bends, thereby increasing the length of the electrode in the cell 2 to improve the spatial energy density of the battery.

[0076] In this embodiment of the invention, the outer shell 1 further includes a shell 12 and a side cover plate 13. The shell 12 includes a bottom plate 121 and a connecting side plate surrounding the bottom plate 121 to form a first cavity 125 corresponding to the top cover plate 11 and a second cavity 126 corresponding to the side cover plate 13. After step S700, which involves bending the welded positive electrode tab group to form a first bending structure 211 and bending the welded negative electrode tab group 22 to form a second bending structure 221, the invention further includes: S8001. Place the battery cell 2 in the housing 12 and cover the housing 12 with the top cover plate 11. Specifically, after placing the battery cell 2 in the housing 12, the top cover plate 11 can be correspondingly covered on the housing 12.

[0077] S8002. The top cover plate 11 and the housing 12 are welded together to seal the first cavity 125. Specifically, the top cover plate 11 and the housing 12 can be welded together using laser welding technology.

[0078] S8003, Cover the housing 11 and the top cover 12 with the side cover plate 13.

[0079] S8004. The side cover plate 13, the top cover plate 11 and the shell 12 are welded together to seal the second cavity 126. Specifically, the side cover plate 13, the top cover plate 11 and the shell 12 can be welded together using laser welding technology to form a shell 12 that is sealed except for the area where the injection hole 127 is connected to the outside.

[0080] In this embodiment of the invention, the housing 12, the top cover plate 11, or the side cover plate 13 are provided with a liquid injection hole 127 communicating with the interior of the housing 1. After step S8004, which involves welding the side cover plate 13, the top cover plate 11, and the housing 12 together to seal the second cavity 126, the method further includes: S900, electrolyte is injected into the outer casing 1 through the injection hole 127, and the injection hole 127 is sealed with a sealing pin. Specifically, the sealing pin can be welded to the outer casing 1. The method of connecting the sealing pin to the outer casing 1 is existing technology and will not be described in detail here.

[0081] In the manufacturing method of the square battery in this embodiment of the invention, since the top cover plate 11 is set independently, it can be placed flat, thus avoiding interference with the laser welding optical path. Therefore, this invention can utilize the ultra-short plate-shaped first adapter piece 5 and directly weld the negative electrode tab group 22 to the top cover plate 11 without bending the first adapter piece 5. The process is simple, and only the first bending structure 211 and the second bending structure 221 need to be set. The bending morphology structure is simple and occupies little space. It can ensure that the positive electrode tab group 21 and the negative electrode tab group 22 are not pulled and broken during the bending process, and can also improve the internal space utilization of the battery, thereby increasing the battery energy density.

[0082] Example 5 The difference between this embodiment and embodiment two is that only the second adapter piece 6 is provided, and the first adapter piece 5 is not provided. That is, the positive electrode tab group 21 is directly welded to the positive electrode post 3, and the negative electrode tab group 22 is welded to the top cover plate 11 through the second adapter piece 6. Therefore, the manufacturing method of the square battery 10 in this embodiment is used to manufacture the square battery 10 with only the second adapter piece 6 provided, and includes the following steps: S1000, Place the top cover plate 11 flat with the welding surface of the top cover plate 11 and the welding surface of the positive electrode post 3 facing upward; specifically, the top cover plate 11 is an independently set component, so the top cover plate 11 can be placed flat to facilitate the welding of the second adapter piece 6 on the top cover plate 11 in step S2000, and to facilitate the welding connection of the positive electrode tab group 21 to the positive electrode post 3 and the welding connection of the negative electrode tab group 22 to the second adapter piece 6 in steps S5000 and S6000.

[0083] S2000. Weld the second adapter piece 6 onto the top cover plate 11. Specifically, the second adapter piece 6 can be welded onto the top cover plate 11 by laser welding.

[0084] S3000, gather the positive electrode tab group 21 of the battery cell 2 toward the first side 201 of the battery cell 2, and place the free end of the positive electrode tab group 21 on the positive electrode post 3; specifically, the battery cell 2 is laid flat so that the free end of the positive electrode tab group 21 can be directly connected to the positive electrode post 3.

[0085] S4000, the negative electrode tab group 22 of the battery cell 2 is brought together to the first side 201 of the battery cell 2, and the free end of the negative electrode tab group 22 is placed on the second adapter plate 6 on the top cover plate 11; specifically, the battery cell 2 is laid flat so that the free end of the negative electrode tab group 22 can be directly connected to the second adapter plate 6.

[0086] S5000, the positive electrode tab group 21 is welded to the positive electrode post 3; specifically, when laser welding is used, the part of the cell 2 other than the part of the positive electrode tab group 21 used to weld to the positive electrode post 3 and the part of the negative electrode tab group 22 used to weld to the second adapter piece 6 will not interfere with the laser path with the top cover plate 11, so that the positive electrode tab group 21 can be directly welded to the positive electrode post 3 from above using laser.

[0087] S6000, the negative electrode tab group 22 is welded to the second adapter piece 6; similarly, when laser welding is used, the parts of the cell 2 other than the part of the positive electrode tab group 21 used to weld to the positive electrode post 3 and the part of the negative electrode tab group 22 used to weld to the second adapter piece 6 will not interfere with the laser path with the top cover plate 11, so that the negative electrode tab group 22 can be directly welded to the second adapter piece 6 from above the top cover plate 11 using laser.

[0088] S7000, the welded positive electrode tab group is bent once to form a first bent structure 211, and the welded negative electrode tab group 22 is bent once to form a second bent structure 221.

[0089] It should be noted that step S5000 can be interchanged with step S4000. That is, after placing the free end of the positive electrode tab group 21 on the positive electrode post 3, the positive electrode tab group 21 and the positive electrode post 3 can be welded directly.

[0090] In this embodiment of the invention, there is only one first bending structure 211 between the positive electrode post 3 and the positive electrode tab group 21, and only one second bending structure 221 between the top cover plate 11 and the negative electrode tab group 22. Under the same internal dimensions, the space occupied by the positive electrode tab group 21, the negative electrode tab group 22, and the second adapter plate 6 in the length direction of the housing 12 is reduced by 30% to 60% compared with the space occupied by the traditional square battery 10 with two bends, thereby increasing the length of the electrode in the cell 2 to improve the spatial energy density of the battery.

[0091] In this embodiment of the invention, the outer shell 1 further includes a shell 12 and a side cover plate 13. The shell 12 includes a bottom plate 121 and a connecting side plate surrounding the bottom plate 121 to form a first cavity 125 corresponding to the top cover plate 11 and a second cavity 126 corresponding to the side cover plate 13. After step S7000, which involves bending the welded positive electrode tab group once to form a first bending structure 211 and bending the welded negative electrode tab group 22 once to form a second bending structure 221, the invention further includes: S80001. Place the battery cell 2 in the housing 12 and cover the housing 12 with the top cover plate 11. Specifically, after placing the battery cell 2 in the housing 12, the top cover plate 11 can be correspondingly covered on the housing 12.

[0092] S80002. The top cover plate 11 and the housing 12 are welded together to seal the first cavity 125. Specifically, the top cover plate 11 and the housing 12 can be welded together using laser welding technology.

[0093] S80003, Cover the housing 12 and the top cover 11 with the side cover 13.

[0094] S80004. The side cover plate 13, the top cover plate 11 and the shell 12 are welded together to seal the second cavity 126. Specifically, the side cover plate 13, the top cover plate 11 and the shell 12 can be welded together using laser welding technology to form a shell 12 that is sealed except for the area where the injection hole 127 is connected to the outside.

[0095] In this embodiment of the invention, the housing 12, the top cover plate 11, or the side cover plate 13 are provided with a liquid injection hole 127 communicating with the interior of the housing 1. After step S80004, which involves welding the side cover plate 13, the top cover plate 11, and the housing 12 together to seal the second cavity 126, the method further includes: S9000 injects electrolyte into the housing 1 through the injection hole 127 and seals the injection hole 127 with a sealing pin. Specifically, the sealing pin can be welded to the housing 1. The method of connecting the sealing pin to the housing 1 is existing technology and will not be described in detail here.

[0096] In the manufacturing method of the square battery in this embodiment of the invention, since the top cover plate 11 is set independently, it can be placed flat, thus avoiding interference with the laser welding optical path. Therefore, this invention can utilize the ultra-short plate-shaped second adapter piece 6 and can directly weld the positive electrode tab group 21 to the positive electrode post 3 without bending the second adapter piece 6. The process is simple, and only the first bending structure 211 and the second bending structure 221 need to be set. The bending morphology structure is simple and occupies little space. It can ensure that the positive electrode tab group 21 and the negative electrode tab group 22 are not pulled and broken during the bending process, and can also improve the internal space utilization of the battery, thereby increasing the battery energy density.

[0097] The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention shall still fall within the scope of the present invention.

Claims

1. A square battery, characterized in that, The device includes a housing and a battery cell disposed within the housing. The housing includes a top cover plate, on which a positive terminal post is provided. The positive terminal post is insulated from the top cover plate. The battery cell includes a group of positive electrode tabs and a group of negative electrode tabs. Both the positive electrode tabs and the negative electrode tabs are located at one end of the battery cell facing the top cover plate. The positive electrode tabs converge toward a first side of the battery cell to form a first bending structure corresponding to a first bending of the positive terminal post. The negative electrode tabs converge toward the first side of the battery cell to form a second bending structure corresponding to a first bending of the top cover plate. The positive electrode tab group is directly welded to the positive electrode post, or the positive electrode tab group is welded to the positive electrode post through a plate-shaped first adapter piece. The negative electrode tab group is directly welded to the top cover plate, or the negative electrode tab group is welded to the top cover plate through a plate-shaped second adapter piece.

2. The square battery as described in claim 1, characterized in that, The outer casing also includes a housing and a side cover plate. The housing includes a bottom plate and a connecting side plate disposed on the bottom plate to form a first cavity corresponding to the top cover plate and a second cavity corresponding to the side cover plate. The top cover plate is disposed on the housing to close the first cavity, and the side cover plate is disposed on the housing and the top cover plate to close the second cavity.

3. The square battery as described in claim 2, characterized in that, The shell is a one-piece structure.

4. The square battery as described in claim 2, characterized in that, The first bending structure has a first bending area, which is located close to the base plate and the distance between the first bending area and the base plate is greater than or equal to 0 and less than or equal to 3 mm.

5. The square battery as described in claim 2, characterized in that, The second bending structure has a second bending area, which is located close to the base plate and the distance between the second bending area and the base plate is greater than or equal to 0 and less than or equal to 3 mm.

6. The square battery as described in claim 2, characterized in that, The length of the housing is greater than or equal to 10 mm and less than or equal to 40 mm, the width of the housing is greater than or equal to 10 mm and less than or equal to 30 mm, and the height of the housing is greater than or equal to 3 mm and less than or equal to 6 mm.

7. The square battery as described in claim 2, characterized in that, The top cover, the side cover, and the housing are all metal structures.

8. A method for manufacturing a square battery as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Place the top cover plate flat with the welding surface of the top cover plate and the welding surface of the positive electrode column facing upwards; The positive electrode tabs of the battery cell are brought together to the first side of the battery cell, and the free end of the positive electrode tabs is placed on the positive terminal or the first adapter piece on the positive terminal. The negative electrode tabs of the battery cell are brought together to the first side of the battery cell, and the free end of the negative electrode tabs is placed on the top cover plate or the second adapter plate on the top cover plate. The positive electrode tab group is welded to the positive electrode post, or the positive electrode tab group is welded to the first adapter piece. The negative electrode tab group is welded to the top cover plate, or the negative electrode tab group is welded to the second adapter piece. The welded positive electrode tab group is bent once to form the first bent structure, and the welded negative electrode tab group is bent once to form the second bent structure.

9. The method for manufacturing a square battery as described in claim 7, characterized in that, The outer casing also includes a housing and side cover plates. The housing includes a bottom plate and connecting side plates surrounding the bottom plate to form a first cavity corresponding to the top cover plate and a second cavity corresponding to the side cover plates. After the steps of bending the welded positive electrode tab group to form the first bent structure and bending the welded negative electrode tab group to form the second bent structure, the casing further includes: The battery cell is placed in the housing and the top cover is placed on the housing; The top cover plate is welded to the housing to seal the first cavity opening; The side cover plate is placed over the housing and the top cover plate; The side cover plate, the top cover plate, and the housing are welded together to seal the second cavity.

10. The method for manufacturing a square battery as described in claim 9, characterized in that, After the step of welding the side cover plate, the top cover plate, or the side cover plate to seal the second cavity, the method further includes: Electrolyte is injected into the housing through the injection hole, and the injection hole is sealed with a sealing pin.

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