Battery housing, secondary battery and manufacturing method therefor

Abstract

Provided is a battery housing (100), comprising a casing (10). The casing (10) is provided with an accommodation cavity (11) having a cavity opening (11a) and used for placing an electrode core (300). The cavity opening (11a) comprises a first cavity opening (111) located on an end wall surface (12) of the casing (10) and a second cavity opening (112) located on a side wall surface (13) of the casing (10), the first cavity opening (111) and the second cavity opening (112) being in communication with each other. The battery housing (100) can overcome the technical defect that laser cannot be placed vertically during the welding process of terminals (240) and tabs of the electrode core (300), thereby facilitating the laser welding of the terminals (240) and the tabs of the electrode core (300), and improving working efficiency. Also provided are a secondary battery (1000) and a manufacturing method therefor.

Description

Battery casing, secondary battery and its manufacturing method Technical Field

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

[0002] As is well known, lithium-ion batteries are a type of rechargeable battery that can be widely used as power batteries in the new energy field.

[0003] For a square casing of a lithium-ion battery, it includes a housing and a top cover. The housing includes a square base plate and four side walls that bend upwards from the four sides of the base plate. These four side walls and the base plate together define a receiving cavity with only one upward-facing opening. Meanwhile, the terminals are usually located on the side walls of the housing. Therefore, during the welding process of the terminals and the electrode tabs, the side walls of the housing block the light source, causing the laser to be positioned at an angle rather than vertically, making the welding of the electrode tabs and terminals difficult. Furthermore, before welding, the housing and the electrode are placed vertically; after welding, they need to be flipped closer together, further increasing the welding difficulty.

[0004] Therefore, there is an urgent need for a battery casing, a secondary battery, and a method for manufacturing them to overcome the aforementioned defects.

[0005] Application content

[0006] One objective of this application is to provide a battery casing that solves the technical problem that the laser cannot be vertically positioned during the electrode tab welding process between the electrode post and the electrode core.

[0007] Another objective of this application is to provide a secondary battery that solves the technical problem that the laser cannot be vertically positioned during the electrode tab welding process between the electrode post and the electrode core.

[0008] Another objective of this application is to provide a method for manufacturing a secondary battery that solves the technical problem that the laser cannot be placed vertically during the electrode tab welding process between the electrode post and the electrode core.

[0009] To achieve the above objectives, the battery casing of this application includes a housing. The housing has a receiving cavity with an opening for placing the electrode core, characterized in that the opening includes a first opening located on the end wall of the housing and a second opening located on the side wall of the housing, the first opening and the second opening being in communication with each other.

[0010] Compared with the existing technology, since the cavity includes a first cavity on the end wall of the housing and a second cavity on the side wall of the housing, and the first cavity and the second cavity are interconnected, the side wall where the second cavity of the housing is located will not obstruct the vertical placement of the laser. This solves the technical defect that the laser cannot be placed vertically during the electrode tab welding process of the electrode post and the electrode core, thus making the laser welding of the electrode post and the electrode core easier, simplifying the manufacturing process and improving work efficiency.

[0011] Preferably, the housing includes a sheet substrate, two first sidewalls bent from two opposing first sides of the substrate, and a second sidewall bent from a second side of the substrate adjacent to the first side to be adjacent to the two first sidewalls. The first sidewall, the second sidewall, and the substrate define the receiving cavity. The first cavity opening is opposite to the second sidewall, and the second cavity opening is opposite to the substrate.

[0012] Preferably, the first sidewall and the second sidewall together form an integral structure; the first sidewall, the second sidewall and the substrate are perpendicular to each other.

[0013] Preferably, the battery casing of this application further includes a side cover and an end cover, wherein the side cover covers the side wall surface where the second cavity is located and closes the second cavity, and the end cover covers the end wall surface where the first cavity is located and closes the first cavity.

[0014] Preferably, the end cap has a mating surface that mates with the end wall surface where the first cavity is located and a positioning boss protruding from the mating surface. The positioning boss is positioned and embedded in the receiving cavity from the first cavity, and the side wall surface where the second cavity is located is flush with the end cap.

[0015] Preferably, the side cover and end cover are both sheet-like structures, and the side cover, end cover and shell are all metal structures.

[0016] To achieve the above objectives, the secondary battery of this application includes a terminal assembly, the aforementioned battery casing, and an electrode core with a first tab and a second tab. The terminal assembly is assembled to the end cap and is insulated from the end cap. The electrode core is placed in the receiving cavity. The first tab of the electrode core is welded to the terminal in the terminal assembly, and the second tab of the electrode core is welded to the end cap.

[0017] Compared with the existing technology, since the cavity includes a first cavity on the end wall of the housing and a second cavity on the side wall of the housing, and the first cavity and the second cavity are interconnected, the side wall where the second cavity of the housing is located will not obstruct the vertical placement of the laser. This solves the technical defect that the laser cannot be placed vertically during the welding process of the first tab of the pole post and the second tab of the pole core to the end cap, thus making the laser welding of the tabs of the pole post and the pole core easier, simplifying the manufacturing process and improving work efficiency.

[0018] Preferably, the electrode assembly includes a metal gasket, a first insulating element, a second insulating element, and the electrode. The end cap has a mounting through hole, and the electrode passes through the mounting through hole. One end of the electrode has a first lateral protrusion structure located outside the mounting through hole, and the other end of the electrode has a second lateral protrusion structure located outside the mounting through hole. The metal gasket, the first insulating element, and the second insulating element are fitted over the electrode at a position between the first and second lateral protrusion structures. The first insulating element and the metal gasket are also sandwiched between the first lateral protrusion structure and the end cap, and the second insulating element is sandwiched between the second lateral protrusion structure and the end cap. The first insulating element and / or the second insulating element also extend into the mounting through hole.

[0019] Preferably, the secondary battery of this application further includes a sealing pin, and the housing, end cap or side cover has an injection hole communicating with the receiving cavity. The sealing pin is assembled on the housing, end cap or side cover where the injection hole is located, and the sealing pin also seals the injection hole.

[0020] To achieve the above objectives, the manufacturing method of the secondary battery of this application includes the following steps:

[0021] (1) Insert the electrode core into the receiving cavity of the housing through the cavity opening, so that the first electrode tab of the electrode core is welded to the electrode post and the second electrode tab of the electrode core is welded to the top cover;

[0022] (2) Assemble the end cap to the first cavity and the side cap to the second cavity. Weld the end cap, side cap and shell together to form a sealed battery shell with a reserved liquid injection hole.

[0023] (3) Inject electrolyte into the filling hole of the battery casing;

[0024] (4) Assemble the sealing pin into the injection hole and weld the sealing pin to the battery casing.

[0025] Compared with the existing technology, since the cavity includes a first cavity on the end wall of the housing and a second cavity on the side wall of the housing, and the first cavity and the second cavity are interconnected, the side wall where the second cavity of the housing is located will not obstruct the vertical placement of the laser. This solves the technical defect that the laser cannot be placed vertically during the welding process of the first tab of the pole post and the second tab of the pole core to the end cap, thus making the laser welding of the tabs of the pole post and the pole core easier, simplifying the manufacturing process and improving work efficiency. Attached Figure Description

[0026] Figure 1 is a perspective view of the secondary battery of this application.

[0027] Figure 2 is a three-dimensional exploded view of the secondary battery shown in Figure 1.

[0028] Figure 3 is a perspective view of Figure 2 after the side cover is hidden and the end cover is flipped 90 degrees.

[0029] Figure 4 is a three-dimensional view of Figure 2 after the pole core is hidden.

[0030] Figure 5 is a perspective view of the secondary battery shown in Figure 1 after the side cover, sealing pins, and electrode core are hidden.

[0031] Figure 6 is an internal view of the end cap and its pole assembly obtained by cutting it with a vertical plane passing through the center line of the pole assembly. Detailed Implementation

[0032] To illustrate the technical content and structural features of this application in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0033] Please refer to Figures 1 to 3. The secondary battery 1000 of this application includes a battery casing 100, an electrode assembly 200, and an electrode core 300 with a first electrode tab 310 and a second electrode tab 320. Optionally, as an example, the electrode core 300 may be a wound electrode core. Obviously, depending on actual needs, the electrode core 300 may also be a folded electrode core, so it is not limited thereto.

[0034] Referring again to Figures 3 and 4, the battery casing 100 includes a housing 10, a side cover 20, and an end cover 30. The housing 10 has a receiving cavity 11 with an opening 11a for placing the electrode core 300. The opening 11a includes a first opening 111 located on the end wall surface 12 of the housing 10 and a second opening 112 located on the side wall surface 13 of the housing 10. The first opening 111 and the second opening 112 are interconnected. Optionally, as an example in Figure 4, both the first opening 111 and the second opening 112 are square openings, but this is not a limitation. The side cover 20 covers the side wall surface 13 where the second opening 112 is located and closes the second opening 112. The end cover 30 covers the end wall surface 12 where the first opening 111 is located and closes the first opening 111, thus satisfying the need to close the opening 11a of the receiving cavity 11. The pole assembly 200 is mounted on and insulated from the end cap 30 to meet the requirement that the pole assembly 200 and the end cap 30 are configured with different polarities. The pole core 300 is placed in the receiving cavity 11. The first tab 310 of the pole core 300 is welded to the pole 240 in the pole assembly 200, and the second tab 320 of the pole core 300 is welded to the end cap 30. Therefore, by means of the assembly of the end cap 30 with the housing 10, and the mounting of the pole assembly 200 on the end cap 30, the welding between the first tab 310 and the pole 240, and the welding between the second tab 320 and the end cap 30, can be arranged before or after the pole core 300 is placed in the receiving cavity 11, thus facilitating the welding operations between the first tab 310 and the pole 240, and between the second tab 320 and the end cap 30. More specifically, as follows:

[0035] Referring to Figures 1 to 4, as an example, the secondary battery 1000 of this application also includes a sealing pin 400. The housing 10 has a liquid injection hole 16 communicating with the receiving cavity 11. The sealing pin 400 is fitted onto the housing 10 and seals the liquid injection hole 16, so that the operator can easily perform liquid injection operations on the receiving cavity 11, which is closed by the end cap 30 and the side cap 20. The sealing pin 400 is used to seal the liquid after injection to prevent liquid leakage. Specifically, in Figures 1 to 4, as an example, the liquid injection hole 16 is located on a first side wall 10b described below, and the sealing pin 400 is fitted onto the first side wall 10b accordingly. Obviously, depending on actual needs, the liquid injection hole 16 can also be opened by the end cap 30 or the side cap 20, so it is not limited to what is shown in Figures 1 to 4.

[0036] As shown in Figures 5 and 6, as an example, the end cap 30 has a mating surface 31 that mates with the end wall surface 12 where the first cavity 111 is located, and a positioning boss 32 protruding from the mating surface 31. The positioning boss 32 is positioned and embedded in the receiving cavity 11 from the first cavity 111. The side wall surface 13 where the second cavity 112 is located is flush with the end cap 30, as shown in Figure 5. This design facilitates the precise and quick assembly of the end cap 30 at the first cavity 111, and the assembly at the first cavity 111 does not protrude relative to the side wall surface 13 where the second cavity 112 is located. Therefore, it is convenient for the side cap 20 to be surface-to-surface with the side wall surface 13 where the second cavity 112 is located, as well as the side cap 20 to be surface-to-surface with the end cap 30, thereby ensuring the reliability of the welding and sealing of the side cap 20 with the end cap 30 and the side wall surface 13 where the second cavity 112 is located. Specifically, as shown in Figures 2 to 5, as an example, both the side cover 20 and the end cover 30 are sheet-like structures to facilitate their manufacturing and processing. Furthermore, the side cover 20, end cover 30, and housing 10 are all metal structures, such as, but not limited to, hardware structures, preferably stainless steel or other alloy materials, to increase the structural strength of the battery housing 10. In addition, the wall thickness of the housing 10 can range from 0.1 mm to 5 mm; for example, the wall thickness of the housing 10 is 0.1 mm or 0.3 mm. The dimensions are 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, 2.7 mm, 2.9 mm, 3.1 mm, 3.3 mm, 3.5 mm, 3.7 mm, 3.9 mm, 4.1 mm, 4.3 mm, 4.5 mm, 4.7 mm, 4.9 mm, or 5 mm, to better meet the requirements of the housing 10 being manufactured by a stamping process.

[0037] As shown in Figure 6, as an example, the pole assembly 200 includes a metal gasket 210, a first insulating member 220, a second insulating member 230, and the aforementioned pole 240. The end cap 30 has a mounting through hole 33, and the pole 240 passes through the mounting through hole 33. One end of the pole 240 has a first lateral protrusion structure 241 located outside the mounting through hole 33, and the other end of the pole 240 has a second lateral protrusion structure 242 located outside the mounting through hole 33. The metal gasket 210, the first insulating member 220, and the second insulating member 230 are fitted onto the pole post 240 at position 243 between the first lateral protrusion structure 241 and the second lateral protrusion structure 242. The first insulating member 220 and the metal gasket 210 are also sandwiched between the first lateral protrusion structure 241 and the end cap 30, and the second insulating member 230 is sandwiched between the second lateral protrusion structure 242 and the end cap 30. The second insulating member 230 also extends into the assembly through hole 33, so as to achieve the purpose of insulating and separating the pole post 240 from the end cap 30 by means of the first insulating member 220 and the second insulating member 230. Obviously, according to actual needs, the first insulating member 220 can also extend into the assembly through hole 33, or both the first insulating member 220 and the second insulating member 233 can extend into the assembly through hole 33 at the same time, so it is not limited to what is shown in Figure 6. Specifically, as an example, the metal gasket 210 is a metal washer, and the pole post 240 is also a metal material, preferably aluminum or other alloy material; the first insulating element 220 and the second insulating element 230 are insulating sealing rings made of plastic or composite materials, preferably PP material.

[0038] As shown in Figure 5, as an example, the housing 10 includes a sheet substrate 10a, two opposing first sidewalls 10b bent from two opposing first sides 14 of the substrate 10a, and a second sidewall 10c bent from a second side 15 adjacent to the first side 14 of the substrate 10a, adjacent to the two first sidewalls 10b. The first sidewalls 10b, the second sidewalls 10c, and the substrate 10a define a receiving cavity 11. At this time, the first cavity opening 111 is opposite to the second sidewall 10c, and the second cavity opening 112 is opposite to the substrate 10a, as shown in Figure 5. This design facilitates the integral fabrication of the housing 10 by a stamping process, thus effectively simplifying the manufacturing process of the housing 10. Specifically, as an example in Figures 2 to 5, the first sidewall 10b and the second sidewall 10c together form an integral structure, so no additional welding is required between the first sidewall 10b and the second sidewall 10c, which further simplifies the manufacturing process of the housing 10; in addition, the first sidewall 10b, the second sidewall 10c and the substrate 10a are perpendicular to each other, which makes it easier to stamp and form the housing 10.

[0039] In summary, the manufacturing method of the secondary battery of this application includes the following steps:

[0040] (1) Insert the electrode core 300 into the receiving cavity 11 of the housing 10 through the cavity 11a, so that the first electrode tab 310 of the electrode core 300 is welded to the electrode post 240 and the second electrode tab 320 of the electrode core 300 is welded to the top cover 30, as shown in Figure 3; specifically, in Figure 3, as an example, the electrode core 300 in the receiving cavity 11 is arranged flat so that the first electrode tab 310 and the second electrode tab 320 of the electrode core 300 extend out of the housing 10 from the first cavity 111, thereby facilitating the welding of the first electrode tab 310 to the second side protrusion structure 242 of the electrode post 240. The welding of the second tab 320 to the end cap 30; alternatively, as an example in Figure 3, the electrode core 300 can be laterally inserted into the receiving cavity 11 from the second cavity 112, with the housing 10 providing support for the electrode core 300. At this time, the second tab 320 of the electrode core 300 is also engaged with the flat end cap 30, and the first tab 310 of the electrode core 300 is engaged with the pole post 240 on the flat end cap 30, thereby facilitating the welding operation of the second tab 320 to the end cap 30, and the welding operation of the first tab 310 to the pole post 240.

[0041] (2) Assemble the end cap 30 into the first cavity 111 and the side cap 20 into the second cavity 112. The end cap 30, the side cap 20 and the shell 10 are welded and sealed into a sealed battery shell 100 with a reserved liquid injection hole 16 by welding process.

[0042] (3) Inject electrolyte into the electrolyte injection hole 100 of the battery casing 100;

[0043] (4) Assemble the sealing pin 400 into the liquid injection hole 100 and weld the sealing pin 400 to the battery casing 100 to obtain the secondary battery 1000 shown in Figure 1.

[0044] Compared with the prior art, since the cavity 11a includes a first cavity 111 located on the end wall 12 of the housing 10 and a second cavity 112 located on the side wall 13 of the housing 10, and the first cavity 111 and the second cavity 112 are interconnected, the side wall 13 where the second cavity 112 of the housing 10 is located will not obstruct the vertical placement of the laser. This solves the technical defect that the laser cannot be vertically placed during the welding process of the first tab 310 of the pole post 240 and the first tab 320 of the pole core 300 and the end cap 30, thereby making the laser welding of the first tab 310 of the pole post 240 and the pole core 30 easier, simplifying the manufacturing process and improving work efficiency.

[0045] It is worth noting that although Figure 1 shows that the outer shape of the battery casing 100 in the secondary battery 1000 of this application is square, obviously, depending on actual needs, the shape of the battery casing 100 can also be other examples, such as the outer contour of the cross-section of the battery casing 100 being a regular polygon or a circle, etc., and is not limited thereto. In addition, the side cover 20 can also be provided with the same positioning structure as the positioning boss 32 of the end cover 30, so as to achieve the purpose of accurately and quickly assembling the side cover 20 onto the second cavity 112.

[0046] The above-disclosed examples are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall fall within the scope of this application.

Claims

1. A battery casing, comprising a housing, the housing having an opening for placing an electrode core, characterized in that, The cavity includes a first cavity located on the end wall of the housing and a second cavity located on the side wall of the housing, and the first cavity and the second cavity are in communication with each other.

2. The battery casing according to claim 1, characterized in that, The housing includes a sheet substrate, two first sidewalls bent from two opposite first sides of the substrate, and a second sidewall bent from a second side of the substrate adjacent to the first side to be adjacent to the two first sidewalls. The first sidewall, the second sidewall, and the substrate define the receiving cavity. The first cavity opening is opposite to the second sidewall, and the second cavity opening is opposite to the substrate.

3. The battery casing according to claim 2, characterized in that, The first sidewall and the second sidewall together form an integral structure; the first sidewall, the second sidewall and the substrate are perpendicular to each other.

4. The battery casing according to claim 1, characterized in that, It also includes a side cover and an end cover. The side cover covers the side wall where the second cavity is located and closes the second cavity. The end cover covers the end wall where the first cavity is located and closes the first cavity.

5. The battery casing according to claim 4, characterized in that, The end cap has a mating surface that mates with the end wall surface where the first cavity is located and a positioning boss protruding from the mating surface. The positioning boss is positioned and embedded in the receiving cavity from the first cavity, and the side wall surface where the second cavity is located is flush with the end cap.

6. The battery casing according to claim 4, characterized in that, Both the side cover and the end cover are sheet-like structures, and the side cover, end cover, and shell are all metal structures.

7. A secondary battery, comprising an electrode assembly and an electrode core with a first tab and a second tab, characterized in that, The battery further includes a battery casing according to any one of claims 4 to 6, wherein the terminal assembly is assembled to the end cap and is insulated from the end cap, the electrode core is placed in the receiving cavity, the first tab of the electrode core is welded to the terminal in the terminal assembly, and the second tab of the electrode core is welded to the end cap.

8. The secondary battery according to claim 7, characterized in that, The electrode assembly includes a metal gasket, a first insulating element, a second insulating element, and the electrode. The end cap has an assembly through hole, and the electrode passes through the assembly through hole. One end of the electrode has a first lateral protrusion structure located outside the assembly through hole, and the other end of the electrode has a second lateral protrusion structure located outside the assembly through hole. The metal gasket, the first insulating element, and the second insulating element are fitted over the electrode at a position between the first and second lateral protrusion structures. The first insulating element and the metal gasket are also sandwiched between the first lateral protrusion structure and the end cap, and the second insulating element is sandwiched between the second lateral protrusion structure and the end cap. The first insulating element and / or the second insulating element also extend into the assembly through hole.

9. The secondary battery according to claim 7, characterized in that, It also includes a sealing pin, and the housing, end cap or side cover has an injection hole that communicates with the receiving cavity. The sealing pin is assembled on the housing, end cap or side cover where the injection hole is located, and the sealing pin also seals the injection hole.

10. A method for manufacturing a secondary battery according to claim 7, characterized in that, Includes the following steps: (1) Insert the electrode core into the receiving cavity of the housing through the cavity opening, so that the first electrode tab of the electrode core is welded to the electrode post and the second electrode tab of the electrode core is welded to the top cover; (2) Assemble the end cap to the first cavity and the side cap to the second cavity. Weld the end cap, side cap and shell together to form a sealed battery shell with a reserved liquid injection hole. (3) Inject electrolyte into the filling hole of the battery casing; (4) Assemble the sealing pin into the injection hole and weld the sealing pin to the battery casing.

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