power battery

Abstract

The application discloses a power battery, which comprises a shell, a roll core, a current collecting disc and an explosion-proof valve piece. The shell is sleeved outside the roll core. The shell comprises a shell bottom. A boss part protruding upward is formed on the shell bottom. An exhaust hole penetrating through the shell bottom is arranged at a position of the shell bottom spaced from the boss part. A reinforcing rib protruding upward is arranged at the periphery of the exhaust hole. The upper side of the current collecting disc is welded to the end of the roll core. The lower side of the current collecting disc is welded to the boss part. The reinforcing rib supports the current collecting disc. The explosion-proof valve piece is arranged at the exhaust hole. The application can effectively improve the balance and compactness of the internal structure of the power battery, effectively avoid the explosion risk caused by the blockage of the exhaust hole due to the deformation of the current collecting disc, and effectively improve the problem that the deformation of the shell caused by the increase of the internal air pressure of the power battery affects the deformation / valve opening consistency of the explosion-proof valve piece.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a power battery. BACKGROUND

[0002] At present, lithium ion / sodium ion power batteries gradually become mainstream products in the new energy industry due to the advantages of high energy density, good capacity consistency, and support for large rate charging and discharging. The conventional power battery structure generally only has one liquid injection hole, and the following common problems exist:

[0003] Cylindrical aluminum shell power batteries have many advantages: low cost, lightweight, etc. Due to the softness of the aluminum shell material, when the internal abnormal pressure of the battery increases, the aluminum shell is easy to deform significantly, thereby affecting the opening consistency of the explosion-proof valve piece, and bringing safety risks to the power battery.

[0004] With the optimization of the structure of the power battery and the improvement of the rate demand, the convex formed by the bottom wall of the liquid injection groove in the middle of the shell bottom locally adheres to the current collector plate and is laser penetrated and welded, resulting in a gap between the position around the current collector plate and the shell bottom. When the power battery is rolled or vibrated, the power battery is lack of balance and compactness, and the power battery is easy to break the circuit.

[0005] When the power battery is abnormal and the internal pressure increases, the rapid pressure relief drives the current collector plate to deform, filling the gap with the shell bottom. After the current collector plate deforms, the through hole of the current collector plate for exhausting gas is easy to randomly tilt, causing the non-hole position to block the pressure relief valve and bringing explosion risks. SUMMARY

[0006] The purpose of the present application is to provide a power battery that can solve at least one technical problem in the background art.

[0007] In order to achieve the above-mentioned purpose, the present application provides a power battery, which comprises a shell, a roll core, a current collector plate and an explosion-proof valve piece. The shell is sleeved outside the roll core. The shell comprises a shell bottom. A convex portion protruding upward is formed on the shell bottom. An exhaust hole penetrating the shell bottom is arranged at a position of the shell bottom spaced from the convex portion. A reinforcing rib protruding upward is arranged around the exhaust hole. The upper side of the current collector plate is welded to the end of the roll core. The lower side of the current collector plate is welded to the convex portion. The reinforcing rib supports the current collector plate. The explosion-proof valve piece is arranged at the exhaust hole.

[0008] Optionally, the reinforcing rib has an upper surface abutting the current collector plate, and a plurality of communication grooves penetrating the reinforcing rib are arranged on the upper surface.

[0009] Optionally, a plurality of through holes are distributed on the current collector plate, and the through holes are capable of allowing gas to pass through.

[0010] Optionally, the current collecting plate is provided with a plurality of through holes, which are capable of allowing gas to pass through; at least part of the through holes faces the space inside the reinforcing rib.

[0011] Optionally, the current collecting plate is punched upward to form at least two sunken portions, the current collecting plate is welded to the end of the winding core through the sunken portions, and the through holes are formed in the non-punched area of the current collecting plate.

[0012] Optionally, the current collecting plate is punched upward to form at least two sunken portions, each of the sunken portions defines a sunken groove, and at least part of the sunken groove faces the space inside the reinforcing rib to form an exhaust passage.

[0013] Optionally, the inner side wall of the reinforcing rib and the side wall of the exhaust hole are spaced apart inward and outward, so that a platform surface is formed between the inner side wall of the reinforcing rib and the side wall of the exhaust hole, and the outer edge of the explosion-proof valve plate is attached to the platform surface.

[0014] Optionally, the bottom of the exhaust hole is expanded outward to form an annular stepped surface for attaching a film.

[0015] Optionally, the reinforcing rib and the exhaust hole are integrally punched, stretched and cold extruded.

[0016] Optionally, the middle part of the boss portion is formed with a liquid injection hole.

[0017] In the embodiment of the application, a reinforcing rib is protruded upward around the exhaust hole at the bottom of the shell, the reinforcing rib supports the current collecting plate, so that, in addition to the local attachment and welding of the boss portion and the current collecting plate, the reinforcing rib can support other positions of the current collecting plate upward, which can effectively improve the balance and compactness of the internal structure of the power battery, thereby avoiding the safety risks that may be caused by insufficient balance / compactness. Moreover, when the internal gas pressure of the power battery increases and the valve is opened for pressure relief, the support of the reinforcing rib to the current collecting plate can effectively avoid the explosion risk caused by the blockage of the exhaust hole due to the deformation of the current collecting plate. In addition, due to the arrangement of the reinforcing rib, the strength of the position where the explosion-proof valve plate is arranged is increased, which can effectively improve the problem that the deformation of the shell caused by the increase of the internal gas pressure of the power battery affects the consistency of the deformation / opening of the explosion-proof valve plate when the material of the shell is relatively soft. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the three-dimensional structure of the power battery of the embodiment of the application.

[0019] Figure 2 is a schematic diagram of the cross-sectional structure of the power battery of the embodiment of the application.

[0020] Figure 3is a sectional view of a partial structure of a power battery according to an embodiment of the present application.

[0021] Figure 4 is a sectional view of a partial structure of a shell and an explosion-proof valve according to an embodiment of the present application.

[0022] Figure 5 is a sectional view of a partial structure of a shell according to an embodiment of the present application.

[0023] Figure 6 is a perspective view of a winding core and a current collector according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the technical content, structural features and achieved effects of the present application more apparent, clear and easy to understand, the following will describe the specific embodiments of the present application in detail with reference to the accompanying drawings.

[0025] In order to make the technical content, structural features and achieved effects of the present application more apparent, clear and easy to understand, the following will describe the specific embodiments of the present application in detail with reference to the accompanying drawings.

[0026] Please refer to Figures 1 to 6 The present application discloses a power battery, which comprises a shell 10, a winding core 20, a current collector 30 and an explosion-proof valve 40. The shell 10 is sleeved outside the winding core 20. The shell 10 comprises a shell bottom 11. The shell bottom 11 is provided with a boss portion 12 protruding upward (i.e. towards the inside of the power battery). The shell bottom 11 is provided with an exhaust hole 13 penetrating the shell bottom 11 at a position spaced apart from the boss portion 12. A reinforcing rib 14 protrudes upward around the exhaust hole 13. The upper side of the current collector 30 is welded to the end of the winding core 20. The lower side of the current collector 30 is welded to the boss portion 12. The reinforcing rib 14 supports the current collector 30. The explosion-proof valve 40 is arranged at the exhaust hole 13.

[0027] In the embodiment of the present application, the shell bottom 11 protrudes outwardly at the periphery of the exhaust hole 13 by a reinforcing rib 14, the reinforcing rib 14 supports the current collecting disc 30, so that the shell bottom 11 is locally welded to the boss portion 12 and the current collecting disc 30, and the reinforcing rib 14 can support the current collecting disc 30 at other positions upwardly, which can effectively improve the balance and compactness of the internal structure of the power battery, thereby avoiding the safety risks that may be caused by insufficient balance / compactness. Moreover, when the internal pressure of the power battery increases and the valve is opened to release pressure, the support of the reinforcing rib 14 to the current collecting disc 30 can effectively avoid the explosion risk caused by the blockage of the exhaust hole 13 due to the deformation of the current collecting disc 30. In addition, due to the arrangement of the reinforcing rib 14, the strength of the position where the explosion-proof valve plate 40 is arranged is increased, which can effectively improve the problem that the deformation of the shell 10 caused by the increase of the internal pressure of the power battery affects the consistency of the deformation / opening of the explosion-proof valve plate 40 when the material of the shell 10 is relatively soft.

[0028] In some embodiments, the reinforcing rib 14 has an upper surface 141 that is in contact with the current collecting disc 30, and a plurality of communication grooves 142 are formed in the upper surface 141 and extend through the reinforcing rib 14. Since the reinforcing rib 14 can be in contact with the current collecting disc 30 through the upper surface 141, the support effect can be ensured. When the valve is opened to release pressure, the gas outside the reinforcing rib 14 can flow into the space inside the reinforcing rib 14 through the communication grooves 142, and then be discharged outwardly through the exhaust hole 13, which is conducive to rapid pressure relief.

[0029] Specifically, the plurality of communication grooves 142 are equally spaced on the upper surface 141 of the reinforcing rib 14. Of course, it is not limited thereto.

[0030] Specifically, the communication grooves 142 can be grooves with a V-shaped or U-shaped cross section. Of course, the specific form of the communication grooves 142 is not limited, as long as they can extend through the reinforcing rib 14 to communicate the space outside the reinforcing rib 14 and the space inside the reinforcing rib 14.

[0031] In a specific example, the depth of the communication grooves 142 is H*1 / 3~H*1 / 2, and H is the height of the reinforcing rib 14.

[0032] In some embodiments, the height H of the reinforcing rib 14 is 0.3mm~0.8mm, and the width W is 0.8mm~2.5mm. Of course, it is not limited thereto.

[0033] In some embodiments, the current collecting disc 30 has a plurality of through holes 31 that can allow gas to pass through. That is, when the valve is opened to exhaust, the internal gas can first enter the space between the current collecting disc 30 and the shell bottom 11 through the through holes 31, and then be discharged outwardly through the exhaust hole 13.

[0034] Specifically, the gas entering the space between the current collector plate 30 and the shell bottom 11 can enter the space inside the reinforcing rib 14 through the communication groove 142 on the reinforcing rib 14, and then be discharged outward through the exhaust hole 13.

[0035] Specifically, at least part of the at least one through hole 31 faces the space inside the reinforcing rib 14, so that at least part of the gas discharged through the at least one through hole 31 can directly enter the space inside the reinforcing rib 14, facilitating rapid discharge outward through the exhaust hole 13.

[0036] Specifically, the current collector plate 30 is upwardly punched to form at least two sunken portions 32, each sunken portion 32 defining a sunken groove 33, the current collector plate 30 is welded to the end of the winding core 20 through the sunken portions 32, and the through hole 31 is formed in the non-punched area of the current collector plate 30.

[0037] Further, part of the at least one sunken groove 33 faces the space inside the reinforcing rib 14 to form an exhaust passage, through which at least part of the gas discharged through the at least one through hole 31 can pass and then be discharged outward through the exhaust hole 13. Of course, the sunken groove 33 is not limited to facing the space inside the reinforcing rib 14 to form the exhaust passage.

[0038] In a specific example, in addition to the central through hole 311 corresponding to the winding core through hole 21 and the liquid injection hole 16 on the shell bottom 11, the current collector plate 30 is additionally provided with three through holes 312 surrounding the central through hole 311. In addition, the current collector plate 30 is formed with three sunken portions 32 arranged at intervals in the circumferential direction, and one through hole 312 is respectively arranged between adjacent sunken portions 32.

[0039] In some embodiments, the current collector plate 30 is upwardly punched to form at least two sunken portions 32, each sunken portion 32 defining a sunken groove 33, and part of the at least one sunken groove 33 faces the space inside the reinforcing rib 14 to form an exhaust passage. The gas outside the reinforcing rib 14 can pass through the exhaust passage and be discharged outward through the exhaust hole 13. Of course, the sunken groove 33 is not limited to facing the space inside the reinforcing rib 14 to form the exhaust passage.

[0040] When the reinforcing rib 14 is provided with a plurality of communication grooves 142 and the sunken groove 33 is used to form the exhaust passage, it is beneficial to rapid exhaust.

[0041] In some embodiments, the inner side wall of the reinforcing rib 14 and the side wall of the exhaust hole 13 are arranged at intervals inside and outside, so that a platform surface 131 is formed between the inner side wall of the reinforcing rib 14 and the side wall of the exhaust hole 13, and the outer edge of the explosion-proof valve plate 40 is attached to the platform surface 131. Of course, the installation of the explosion-proof valve plate 40 is not limited to this form.

[0042] Specifically, the explosion-proof valve sheet 40 is laser-welded after being attached to the platform surface 131.

[0043] It can be understood that the explosion-proof valve sheet 40 is lower than the reinforcing ribs 14 as a whole and is spaced apart from the current collector plate 30.

[0044] In some embodiments, the bottom of the exhaust hole 13 is expanded outward to form an annular stepped surface 132 for attaching a film. Since the bottom of the exhaust hole 13 is formed with the annular stepped surface 132 for attaching a film, the height of the power battery is not affected when attaching the film.

[0045] In some embodiments, the reinforcing ribs 14 and the exhaust hole 13 are integrally punched / stretched / cold-extruded. Of course, it is not limited to this.

[0046] In some embodiments, the middle part of the boss part 12 is formed with a liquid injection hole 16.

[0047] Specifically, the boss part 12 is formed with the liquid injection groove 17 on the upper side thereof.

[0048] In some embodiments, the material of the explosion-proof valve sheet 40 is MFX or other aluminum material.

[0049] The above disclosure is only a preferred embodiment of the present application, which is convenient for those skilled in the art to understand and implement. Of course, it cannot be used to limit the scope of the right of the present application, so the equivalent changes made according to the scope of the patent application of the present application still belong to the scope covered by the present application.

Claims

1. A power cell, characterized by The power battery comprises a shell, a winding core, a current collecting disc and an explosion-proof valve sheet, the shell is sleeved outside the winding core, the shell comprises a shell bottom, a boss portion protruding upward is formed on the shell bottom, an exhaust hole penetrating through the shell bottom is arranged at a position of the shell bottom spaced from the boss portion, a reinforcing rib protruding upward is arranged at the periphery of the exhaust hole, the upper side of the current collecting disc is welded to the end of the winding core, the lower side of the current collecting disc is welded to the boss portion, the reinforcing rib supports the current collecting disc, and the explosion-proof valve sheet is arranged at the exhaust hole. The reinforcing rib has an upper surface abutting against the current collecting disc, and a plurality of communication grooves penetrating through the reinforcing rib are arranged on the upper surface. A plurality of through holes are distributed on the current collecting disc, and the through holes are capable of allowing gas to pass through.

2. The power cell of claim 1, wherein, At least part of the area of part of the through holes faces the space inside the reinforcing rib.

3. The power cell of claim 2, wherein, The current collecting disc is upwardly punched to form at least two sunken portions, the current collecting disc is welded to the end of the winding core through the sunken portions, and the through holes are formed in the non-punched area of the current collecting disc.

4. The power cell of claim 1, wherein, The current collecting disc is upwardly punched to form at least two sunken portions, each of the sunken portions defines a sunken groove, and part of the area of at least one of the sunken grooves faces the space inside the reinforcing rib to form an exhaust passage.

5. The power cell of claim 1, wherein, The inner side wall of the reinforcing rib and the side wall of the exhaust hole are arranged in a spaced manner, so that a platform surface is formed between the inner side wall of the reinforcing rib and the side wall of the exhaust hole, and the outer edge of the explosion-proof valve sheet abuts against the platform surface.

6. The power cell of claim 1, wherein, The bottom of the exhaust hole is outwardly expanded to form an annular stepped surface for film pasting.

7. The power cell of claim 1, wherein, The reinforcing rib and the exhaust hole are integrally punched, stretched and cold extruded.

8. The power cell of claim 1, wherein, A liquid injection hole is formed in the middle of the boss portion.

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