Battery cell safety structure and cylindrical battery

Abstract

The utility model provides a battery cell safety structure and a cylindrical battery, the battery cell safety structure comprises a shell, a cell body assembly, an end cover assembly and a sealing nail assembly, the shell is provided with a containing groove, the cell body assembly is installed in the containing groove and connected to the end cover assembly, the end cover assembly covers one end of the shell, and the sealing nail assembly is installed in the containing groove. The end cover assembly is provided with a liquid inlet hole and a mounting hole which are sequentially communicated, the liquid inlet hole is further communicated with the containing groove, the sealing nail assembly comprises a pressure relief piece and a sealing body, the sealing body is installed in the mounting hole, the sealing body is provided with a pressure relief channel communicated with the containing groove, and the sealing body is connected to the pressure relief piece and integrally formed. The face, away from the liquid inlet hole, of the pressure relief piece and the face, away from the liquid inlet hole, of the sealing body are flush with the outer side surface of the end cover assembly. The pressure relief sheet and the sealing body are integrally formed, so that the production is simple, trepanning and explosion-proof valve welding procedures are reduced, and the production cost is reduced; the pressure relief piece and the face, away from the liquid inlet hole, of the sealing body are flush with the end cover assembly, so that the surface of the end cover assembly is smoother.

Description

Technical Field

[0001] The present disclosure relates to the technical field of cylindrical batteries, and particularly to a core safety structure and a cylindrical battery. Background Art

[0002] With the rapid development of the new energy industry, the application of large cylindrical batteries in the power market is gradually increasing. Large cylindrical batteries are mainly used in power and energy storage. Due to the large size and high core capacity of cylindrical batteries, a pressure relief valve design is generally added to the end caps of cylindrical batteries to ensure the safety performance of the cores.

[0003] For cylindrical batteries, a liquid injection port and a pressure relief valve are respectively opened on the end cap first, then a thin aluminum sheet is covered at the corresponding position, and then laser welding is performed to fix the pressure relief valve, which increases the welding process and leads to an increase in production cost; after the sealing nail and the pressure relief valve are respectively welded to the end cap, the surface of the end cap is also uneven.

[0004] As disclosed in the prior art CN201621143053.X, a cylindrical battery explosion-proof cover plate includes a cover plate, on which a positive electrode column or a negative electrode column and corresponding positive and negative electrode column marking symbols, a liquid injection hole position are provided. In addition, an explosion-proof sheet mounting hole position is provided on the cover plate, and a pressure relief port with an enlarged blasting diameter corresponding to the shape is provided on the mounting hole position; an explosion-proof sheet corresponding to the shape is installed on the pressure relief port with the enlarged blasting diameter. However, this solution requires opening a pressure relief port and a liquid injection hole, and also requires installing a corresponding explosion-proof sheet, resulting in an increase in production cost. The explosion-proof sheet also increases the welding process, and the surface of the cylindrical battery is not flat enough after welding the explosion-proof sheet. Summary of the Utility Model

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a core safety structure and a cylindrical battery with lower integrated molding cost and a flat surface.

[0006] The purpose of the present disclosure is achieved by the following technical solutions:

[0007] A core safety structure includes a housing, a core assembly, an end cap assembly, and a sealing nail assembly. The housing is provided with a receiving groove, the core assembly is installed in the receiving groove, the end cap assembly covers one end of the housing, the core assembly is connected to the end cap assembly, the end cap assembly is provided with a liquid inlet hole and a mounting hole that are sequentially communicated, and the liquid inlet hole is also communicated with the receiving groove.

[0008] The sealing nail assembly includes a pressure relief piece and a sealing body. The sealing body is installed in the installation hole. The sealing body is provided with a pressure relief channel, and the pressure relief channel communicates with the accommodating groove. The sealing body is connected to the outer peripheral edge of the pressure relief piece. The pressure relief piece and the sealing body are integrally formed. The pressure relief piece is used for rupturing to relieve pressure when the pressure increases. The surface of the pressure relief piece facing away from the liquid inlet hole and the surface of the sealing body facing away from the liquid inlet hole are both flush with the outer surface of the end cover assembly.

[0009] In one embodiment, the installation hole is a tapered countersunk structure, and the sealing body is a frustum structure.

[0010] In one embodiment, a rounded corner structure is formed at one end of the sealing body facing away from the pressure relief piece.

[0011] In one embodiment, the pressure relief channel is a cylindrical structure.

[0012] In one embodiment, the radius of the pressure relief channel is greater than the radius of the liquid inlet hole.

[0013] In one embodiment, the core assembly includes a winding core, a current collecting plate and a connecting band. The winding core is installed in the accommodating groove. The current collecting plate is welded to one end of the winding core. Two ends of the connecting band are respectively connected to the end cover assembly and the current collecting plate. The current collecting plate is located below the liquid inlet hole.

[0014] In one embodiment, the sealing body is welded to the installation hole.

[0015] In one embodiment, the thickness of the pressure relief piece is 0.17 mm - 0.23 mm.

[0016] In one embodiment, the end cover assembly includes a terminal post and a sealing end cover. The sealing end cover covers the housing. The liquid inlet hole and the installation hole are opened in the sealing end cover. The sealing end cover is further provided with a through hole. The terminal post is installed in the through hole. The terminal post is connected to the core assembly.

[0017] A cylindrical battery includes the battery core installation structure described in any of the above embodiments.

[0018] Compared with the prior art, the present disclosure has at least the following advantages:

[0019] In the above-mentioned battery cell safety structure, the pressure relief piece and the sealing body are integrally formed by one-time stamping, which makes the production of the pressure relief piece and the sealing body simple. The integrally formed pressure relief piece and sealing body reduce the processes of opening the installation hole for the explosion-proof valve and welding the explosion-proof valve in the end cap assembly, thereby reducing the production cost of the battery. The surfaces of the pressure relief piece and the sealing body facing away from the liquid inlet hole are flush with the outer surface of the end cap assembly, making the surface of the end cap assembly smoother and improving the appearance quality of the battery cell. Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of the battery cell safety structure of an embodiment;

[0022] Figure 2 It is a partial enlarged view of the battery cell safety structure at A;

[0023] Figure 3 It is a schematic structural diagram of the sealing nail assembly. Detailed Embodiments

[0024] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present disclosure more thorough and comprehensive.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art belonging to the technical field of the present disclosure. The terms used in the description of the present disclosure herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0027] To better understand the technical solutions and beneficial effects of the present disclosure, the following further describes the present disclosure in detail with specific embodiments:

[0028] As Figures 1 to 3 shown, the cell safety structure 10 of an embodiment of the present disclosure includes a housing 100, a core component 200, an end cover component 300, and a sealing nail component 400. The housing 100 is provided with a receiving groove 101. The core component 200 is installed in the receiving groove 101. The receiving groove 101 can hold electrolyte. The end cover component 300 is covered on one end of the housing 100. The core component 200 is connected to the end cover component 300. The end cover component 300 is provided with a liquid inlet hole 301 and an installation hole 302 that are sequentially communicated. The liquid inlet hole 301 is also communicated with the receiving groove 101. The electrolyte can be injected into the receiving groove 101 through the installation hole 302 and the liquid inlet hole 301.

[0029] Further, the sealing nail component 400 includes a pressure relief piece 410 and a sealing body 420. The sealing body 420 is installed in the installation hole 302. The sealing body 420 is provided with a pressure relief channel 4201. The pressure relief channel 4201 is communicated with the receiving groove 101. The sealing body 420 is connected to the outer peripheral edge of the pressure relief piece 410 to enable the pressure relief piece 410 to seal the pressure relief channel 4201. The pressure relief piece 410 and the sealing body 420 are integrally formed. The pressure relief piece 410 is used to rupture when the pressure rises to relieve pressure. The surface of the pressure relief piece 410 facing away from the liquid inlet hole 301 and the surface of the sealing body 420 facing away from the liquid inlet hole 301 are both flush with the outer surface of the end cover component 300.

[0030] In this embodiment, the pressure relief piece 410 and the sealing body 420 are integrally formed by one stamping process, which makes the production of the pressure relief piece 410 and the sealing body 420 simple, and the dimensional accuracy of the pressure relief piece 410 and the sealing body 420 is ensured with high precision in one stamping. The core component 200 is installed in the receiving groove 101, then the connection part between the core component 200 and the end cover component 300 is welded, the end cover component 300 is welded to the housing 100. After injecting liquid through the liquid inlet hole 301, the integrally formed pressure relief piece 410 and sealing body 420 are installed in the installation hole 302. When the pressure in the receiving groove 101 is too high, the pressure relief piece 410 ruptures, enabling the receiving groove 101 to communicate with the external environment, so that the battery receiving groove 101 relieves pressure, thereby protecting the safety of the cell.

[0031] For the above-mentioned battery cell safety structure 10, the pressure relief piece 410 and the sealing body 420 are integrally formed by one-time stamping, which makes the production of the pressure relief piece 410 and the sealing body 420 simple. The integrally formed pressure relief piece 410 and sealing body 420 reduce the processes of opening the installation hole for the explosion-proof valve and welding the explosion-proof valve in the end cap assembly 300, thus reducing the welding process, and reducing the production cost of the battery. The surfaces of the pressure relief piece 410 and the sealing body 420 facing away from the liquid inlet hole 301 are flush with the outer surface of the end cap assembly 300, making the surface of the end cap assembly 300 smoother and improving the appearance quality of the battery cell.

[0032] As Figure 1 and Figure 2 shown, in one embodiment, the installation hole 302 is a tapered countersunk head structure, and the sealing body 420 is a frustum structure. In this embodiment, the installation hole 302 is tapered, which is beneficial to converging the liquid, thus making the liquid injection process smoother. The sealing body 420 is a frustum structure, so that the sealing body 420 is adaptively installed on the installation hole 302, making the installation of the sealing body 420 convenient and the combination of the installation and the housing 100 tighter.

[0033] As Figure 2 and Figure 3 shown, in one embodiment, a rounded corner structure is formed at one end of the sealing body 420 facing away from the pressure relief piece 410. In this embodiment, by processing one end of the sealing body 420 facing away from the pressure relief piece 410 into a rounded corner, the sharp edge of the sealing body 420 is eliminated, and the stress distribution of the sealing body 420 is also reduced, thus making the structural strength of the sealing body 420 higher.

[0034] As Figure 2 and Figure 3 shown, in one embodiment, the pressure relief channel 4201 is a cylindrical structure. In this embodiment, the pressure relief channel 4201 forms a cylindrical flow channel, and the pressure in the accommodation cavity acts on the pressure relief piece 410 evenly, so that the pressure fluctuation range for the pressure relief piece 410 to rupture is small, and the pressure relief pressure of the pressure relief piece 410 is accurate.

[0035] As Figure 2As shown, in one embodiment, the radius of the pressure relief channel 4201 is greater than the radius of the liquid inlet hole 301. In this embodiment, when the radius of the pressure relief channel 4201 is less than the radius of the liquid inlet hole 301, as the pressure increases, the airflow flowing into the pressure relief channel 4201 generates a thrust on the pressure relief piece 410, causing the sealing body 420 to be driven by the pressure relief piece 410. The sealing body 420 is also pushed by the air pressure in the accommodation cavity to block the liquid inlet hole 301; when the radius of the pressure relief channel 4201 is greater than the radius of the liquid inlet hole 301, the airflow flowing into the pressure relief channel 4201 generates a thrust on the pressure relief piece 410, causing the sealing body 420 to be driven by the pressure relief piece 410. The force on the sealing body 420 is reduced, thereby increasing the connection strength between the sealing body 420 and the housing 100.

[0036] As Figure 1 shown, in one embodiment, the core assembly 200 includes a winding core 210, a current collecting plate 220 and a connecting band 230. The winding core 210 is installed in the accommodation groove 101. The current collecting plate 220 is welded to one end of the winding core 210. The two ends of the connecting band 230 are respectively connected to the end cover assembly 300 and the current collecting plate 220. The current collecting plate 220 is located below the liquid inlet hole 301. In this embodiment, when injecting the electrolyte, the current collecting plate 220 is located below the liquid inlet hole 301, and the connecting band 230 is misaligned with the current collecting plate 220, avoiding the connecting band 230 from blocking the electrolyte, making the process of injecting the electrolyte into the accommodation groove 101 smooth, thereby improving the efficiency of injecting the electrolyte.

[0037] As Figure 2 shown, in one embodiment, the sealing body 420 is welded to the mounting hole 302. In this embodiment, the surfaces of the pressure relief piece 410 and the sealing body 420 are flat, reducing the difficulty of welding the sealing body 420 to the end cover, and keeping the surface of the battery cell flat after the sealing body 420 is welded, thereby improving the appearance quality of the battery cell.

[0038] In one embodiment, the thickness of the pressure relief piece 410 is 0.17 mm - 0.23 mm. In this embodiment, when the pressure relief piece 410 has a thickness of 0.17 mm and a pressure test is performed, the pressure relief piece 410 breaks when the pressure exceeds 1.7 Mpa. When the pressure relief piece 410 has a thickness of 0.23 mm and a pressure test is performed, the pressure relief piece 410 breaks when the pressure exceeds 2.1 Mpa. Controlling the thickness of the pressure relief piece 410 within the range of 0.17 mm - 0.23 mm causes the pressure relief piece 410 to break within the pressure range of 1.7 Mpa - 2.1 Mpa, thereby timely releasing the pressure in the accommodation groove 101 and preventing safety problems caused by excessive internal pressure of the battery cell.

[0039] As Figure 1As shown, in one embodiment, the end cap assembly 300 includes a terminal post 310 and a sealing end cap 320. The sealing end cap 320 covers the housing 100. A liquid inlet hole 301 and a mounting hole 302 are formed in the sealing end cap 320. The sealing end cap 320 is further provided with a through hole 3101. The terminal post 310 is installed in the through hole 3101, and the terminal post 310 is connected to the core component 200. In this embodiment, the sealing end cap 320 is welded to the housing 100. One end of the terminal post 310 is welded to the core component 200, and the terminal post 310 is fixed to the through hole 3101 of the end cap by welding, so that the current of the core component 200 flows out or flows in through the terminal post 310. After injecting liquid through the mounting hole 302 and the liquid inlet hole 301, the pressure relief piece 410 and the sealing body 420 are welded to the mounting hole 302, so that the sealing effect of the accommodating groove 101 is good.

[0040] This application also provides a cylindrical battery including the battery cell safety structure 10 in any of the above embodiments. In this embodiment, the pressure relief piece 410 and the sealing body 420 of the battery cell safety structure 10 are integrally formed, saving the process of opening an explosion-proof valve mounting hole in the housing 100. The side of the pressure relief piece 410 and the sealing body 420 facing away from the liquid inlet hole 301 together form a plane, making the surface of the battery cell flat and increasing the appearance quality of the surface of the battery cell.

[0041] Compared with the prior art, the present disclosure has at least the following advantages:

[0042] For the above-mentioned battery cell safety structure 10 and cylindrical battery, the pressure relief piece 410 and the sealing body 420 are integrally formed by one-time stamping, making the production of the pressure relief piece 410 and the sealing body 420 simple. The integrally formed pressure relief piece 410 and sealing body 420 reduce the explosion-proof valve mounting hole opened in the end cap assembly 300 and the process of welding the explosion-proof valve, thereby reducing the production cost; the surfaces of the pressure relief piece 410 and the sealing body 420 facing away from the liquid inlet hole 301 are flush with the outer surface of the end cap assembly 300, making the surface of the end cap assembly 300 more flat and increasing the appearance quality of the battery cell.

[0043] The above embodiments only represent several implementation manners of the present disclosure, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the disclosed patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several deformations and improvements can still be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A battery safety structure, comprising a shell, a core assembly, an end cover assembly and a sealing nail assembly, wherein the shell is provided with a receiving groove, the core assembly is installed in the receiving groove, the end cover assembly is covered at one end of the shell, the core assembly is connected to the end cover assembly, the end cover assembly is provided with a liquid inlet hole and a mounting hole connected in sequence, the liquid inlet hole is also connected to the receiving groove, characterized in that: The sealing nail assembly includes a pressure relief piece and a sealing body, the sealing body is installed in the installation hole, the sealing body is provided with a pressure relief channel, the pressure relief channel is connected to the accommodating groove, the sealing body is connected to the outer periphery of the pressure relief piece, the pressure relief piece and the sealing body are integrally formed, the pressure relief piece is used to rupture and relieve pressure when the pressure increases, and a side of the pressure relief piece facing away from the liquid inlet hole and a side of the sealing body facing away from the liquid inlet hole are both flush with the outer surface of the end cover assembly.

2. The battery safety structure according to claim 1, characterized in that: The mounting hole is a conical countersunk structure, and the sealing body is a truncated cone structure.

3. The battery safety structure according to claim 2, characterized in that: A rounded structure is formed on one end of the sealing body away from the pressure relief plate.

4. The battery cell safety structure according to claim 1, characterized in that: The pressure relief channel is a cylindrical structure.

5. The battery cell safety structure according to claim 4, characterized in that: The radius of the pressure relief channel is greater than the radius of the liquid inlet hole.

6. The battery cell safety structure according to claim 1, characterized in that: The core assembly includes a winding core, a conduit plate and a connecting belt. The winding core is installed in the accommodating groove. The conduit plate is welded to one end of the winding core. The two ends of the connecting belt are respectively connected to the end cover assembly and the conduit plate. The conduit plate is located below the liquid inlet hole.

7. The battery cell safety structure according to claim 1, characterized in that: The sealing body is welded to the mounting hole.

8. The battery cell safety structure according to claim 1, characterized in that: The thickness of the pressure relief sheet is 0.17 mm-0.23 mm.

9. The battery cell safety structure according to claim 1, characterized in that: The end cover assembly includes a pole and a sealing end cover, the sealing end cover is covered on the shell, the liquid inlet hole and the mounting hole are opened on the sealing end cover, the sealing end cover is also opened with a through hole, the pole is installed in the through hole, and the pole is connected to the core assembly.

10. A cylindrical battery, characterized in that: The invention comprises the battery cell safety structure according to any one of claims 1 to 9.

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