Shell of power battery and power battery

Abstract

The shell comprises a side wall, the side wall is used for being arranged on the outer side of a roll core of the power battery in a sleeved mode, the side wall comprises a side wall main body and a necking part which is connected to the top end of the side wall main body and contracts inwards relative to the side wall main body, the inner side of the top face of the necking part is sunken downwards to form an annular downwards-concave platform, and the annular downwards-concave platform is arranged on the side wall main body. The annular downward-concave platform is used for being in lap joint with the outer edge of the collector plate, an inward-concave area is formed on the outer surface, opposite to the side wall body, of the outer side of the necking part, and the inward-concave area is used for containing and supporting the annular downward-convex portion of the sealing soldering lug. According to the utility model, the laser welding power can be effectively reduced, and the risk of shell wall penetration or pseudo soldering is avoided. Moreover, the current collecting disc can be welded and fixed on the shell, so that the torque resistance of the cylindrical roll core is improved, and the risk of open circuit of the battery is avoided. In addition, the collector plate is fixed on the side wall of the shell through laser seam welding, so that a large welding area is achieved, and high-rate charging and discharging of the power battery can be conveniently realized.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a casing and a power battery. Background Technology

[0002] Currently, lithium-ion / sodium-ion cylindrical power batteries are gradually becoming the mainstream product in the new energy industry due to their advantages such as high energy density, good capacity consistency, and ability to support high-rate charging and discharging. With the popularization of new energy vehicles, people have placed higher demands on fast-charging travel (i.e., high-rate fast charging of power batteries) and long-life consistency of power batteries. However, current power batteries have the following problems:

[0003] (1) After the current collector is welded into the cylindrical power battery core, it is directly inserted into the shell and assembled with the bottom of the shell by resistance welding or laser penetration welding. The welding area is relatively small, making it difficult to achieve high-rate charging and discharging, and the temperature rise is also relatively large.

[0004] (2) When cylindrical power batteries are installed in vehicles and subjected to long-term vibration or roller testing, the core drives the current collector connecting piece and the top cover connecting piece to rotate. The large torque directly impacts the welding position, causing the battery to open circuit.

[0005] (3) A few manufacturers have begun to explore the side wall welding assembly of cylindrical power battery current collectors into the shell, that is, laser welding of the current collector to the side wall of the shell. However, due to the thinness of the side wall of the shell, it is easy to weld through the side wall of the shell or to produce a false weld, resulting in a lot of welding defects. Utility Model Content

[0006] The purpose of this utility model is to provide a casing and a power battery that can solve at least one of the technical problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides a housing for a power battery. The housing includes a sidewall for fitting around the outer side of the battery core. The sidewall includes a main body and a constricted portion connected to the top of the main body and tapering inward relative to the main body. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The annular concave platform is used for the outer edge of the current collector to overlap. The outer side of the constricted portion forms an inward concave region relative to the outer surface of the main body. The inward concave region is used to accommodate and support the annular downward protrusion of the sealing weldment.

[0008] In this embodiment of the invention, a constricted portion is formed at the top of the side wall of the housing. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The annular concave platform is used for the outer edge of the current collector to overlap. The outer side of the constricted portion forms an inward concave region relative to the outer surface of the main body of the side wall. The inward concave region is used to accommodate and support the annular downward protrusion of the sealing weld. Since the outer edge of the current collector can overlap the annular concave platform, the current collector can be fixed to the side wall of the housing by laser seam welding, eliminating the need for high-power laser penetration welding, effectively reducing laser welding power and effectively avoiding the risk of welding through the housing wall or incomplete welding. Moreover, since the current collector can be welded and fixed to the housing, the torque resistance of the cylindrical core is effectively improved, avoiding the risk of battery open circuit. In addition, since the current collector is fixed to the side wall of the housing by laser seam welding, it has a large welding area, which facilitates high-rate charging and discharging of the power battery and can effectively suppress excessive temperature rise.

[0009] Optionally, the constricted portion includes a bent portion and a vertical portion. The lower end of the bent portion is connected to the main side wall, the upper end of the bent portion is connected to the lower end of the vertical portion, and the inner side of the top surface of the vertical portion is recessed downward to form the annular concave platform.

[0010] Optionally, the recessed region includes a vertical wall and a sloping wall, the lower end of the vertical wall and the upper end of the sloping wall are connected, the lower end of the sloping wall is connected to the outer surface of the sidewall body, and the vertical wall and the sloping wall are configured to fit the annular downward protrusion of the sealing weld.

[0011] Optionally, the recessed region includes a sloping wall surface or an overlapping platform surface adapted to the annular downward protrusion of the sealing sheet.

[0012] Optionally, the housing is integrally stamped and stretched.

[0013] Optionally, the housing is cylindrical in shape, and the constricted portion has a smaller radial dimension relative to the overall housing.

[0014] To achieve the above objectives, this utility model also provides a power battery, which includes a core, a current collector, a housing, and a sealing weld. The current collector is welded to the tab at the top of the core. The housing includes a sidewall that is fitted over the outside of the core. The sidewall includes a main body and a constricted portion connected to the top of the main body and tapering inward relative to the main body. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The outer edge of the current collector overlaps the annular concave platform and is fixed to the constricted portion by laser seam welding. The outer side of the constricted portion forms a concave region relative to the outer surface of the main body. The outer edge of the sealing weld protrudes downward from the annular concave region and is accommodated and supported in the concave region and fixed by laser welding.

[0015] Optionally, the constricted portion includes a bent portion and a vertical portion. The lower end of the bent portion is connected to the main side wall, the upper end of the bent portion is connected to the lower end of the vertical portion, and the inner side of the top surface of the vertical portion is recessed downward to form the annular concave platform.

[0016] Optionally, the recessed region includes a vertical wall and a sloping wall, the lower end of the vertical wall and the upper end of the sloping wall are connected, the lower end of the sloping wall is connected to the outer surface of the side wall body, and the vertical wall and the sloping wall are adapted to the annular downward protrusion of the sealing weld.

[0017] Optionally, the recessed region includes a sloping wall surface or an overlapping platform surface adapted to the annular downward protrusion of the sealing sheet.

[0018] In this embodiment of the invention, a constricted portion is formed at the top of the side wall of the housing. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The outer edge of the current collector overlaps the annular concave platform and is fixed to the constricted portion by laser seam welding. The outer side of the constricted portion forms an inward concave region relative to the outer surface of the main side wall. The outer edge of the sealing weld plate protrudes downward from the annular concave protrusion, which is accommodated and supported in the inward concave region and fixed by laser welding. Because the outer edge of the current collector overlaps the annular concave platform and is fixed to the constricted portion by laser seam welding, there is no need to use high-power laser penetration welding, which can effectively reduce the laser welding power and effectively avoid the risk of welding through the housing wall or incomplete welding. Moreover, since the current collector can be welded and fixed to the housing, the torque resistance of the cylindrical core is effectively improved, avoiding the risk of battery open circuit. In addition, since the current collector is fixed to the constricted portion by laser seam welding, it has a large welding area, which facilitates high-rate charging and discharging of the power battery and can effectively suppress excessive temperature rise. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the shell of an embodiment of this utility model.

[0020] Figure 2 yes Figure 1 Enlarged view of part A in the middle.

[0021] Figure 3 This is a cross-sectional structural diagram of the shell of an embodiment of this utility model.

[0022] Figure 4 yes Figure 3 Enlarged view of section B in the middle.

[0023] Figure 5 This is a cross-sectional structural schematic diagram of the shell of this utility model embodiment from another perspective.

[0024] Figure 6 yes Figure 5 Enlarged view of section C.

[0025] Figure 7 This is a cross-sectional structural diagram of the power battery according to an embodiment of the present invention.

[0026] Figure 8 yes Figure 7 Enlarged view of section D in the middle. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0028] Example 1

[0029] Please see Figures 1 to 8 This utility model discloses a power battery housing 10. The housing 10 includes a side wall 11, which is used to fit around the outer side of the power battery core 20. The side wall 11 includes a side wall body 12 and a constricted portion 13 connected to the top of the side wall body 12 and converging inward relative to the side wall body 12. The inner side of the top surface of the constricted portion 13 is recessed downward to form an annular concave platform 130. The annular concave platform 130 is used for the outer edge of the collector plate 30 to overlap. The outer side of the constricted portion 13 forms an inward concave region 14 relative to the outer surface of the side wall body 12. The inward concave region 14 is used to accommodate and support the annular protrusion 41 of the sealing weld plate 40.

[0030] In this embodiment of the invention, a constricted portion 13 is formed at the top of the side wall 11 of the housing 10. The inner side of the top surface of the constricted portion 13 is recessed downward to form an annular recessed platform 130. The annular recessed platform 130 is used for the outer edge of the current collector 30 to overlap. The outer side of the constricted portion 13 forms an inner recessed region 14 opposite to the outer surface of the side wall body 12. The inner recessed region 14 is used to accommodate and support the annular protrusion 41 of the sealing welding piece 40. Since the outer edge of the current collector 30 can overlap the annular recessed platform 130, the current collector 30 can be fixed to the side wall 11 of the housing 10 by laser seam welding. This eliminates the need for high-power laser penetration welding, effectively reducing laser welding power and avoiding the risk of welding through the housing wall or incomplete welding. Moreover, since the current collector 30 can be welded and fixed to the housing 10, the torque resistance of the cylindrical core 20 is effectively improved, avoiding the risk of battery open circuit. In addition, since the current collector 30 and the side wall 11 of the housing 10 are fixed by laser seam welding, they have a large welding area, which facilitates the high-rate charging and discharging of the power battery and can effectively suppress excessive temperature rise.

[0031] In some embodiments, the constricted portion 13 includes a bent portion 131 and a vertical portion 132. The lower end of the bent portion 131 is connected to the sidewall body 12, and the upper end of the bent portion 131 is connected to the lower end of the vertical portion 132. The inner side of the top surface of the vertical portion 132 is recessed downward to form an annular recessed platform 130. Of course, the constricted portion 13 is not limited to including the bent portion 131 and the vertical portion 132.

[0032] Specifically, the recessed region 14 includes a vertical wall 141 and a sloping wall 142. The lower end of the vertical wall 141 is connected to the upper end of the sloping wall 142, and the lower end of the sloping wall 142 is connected to the outer surface of the sidewall body 12. The vertical wall 141 and the sloping wall 142 are configured to fit with the annular downward protrusion 41 of the sealing weld 40.

[0033] More specifically, the sloping wall 142 is an integrally concave curved surface that is smoothly connected to the vertical wall 141.

[0034] In some embodiments, the recessed region 14 includes a sloping wall 142 adapted to the annular protrusion 41 of the sealing sheet 40, specifically a curved surface that is integrally recessed. Of course, the recessed region 14 is not limited to including the sloping wall 142; for example, its bottom may also have an overlapping platform surface for the annular protrusion 41 of the sealing sheet 40 to overlap.

[0035] In some embodiments, the housing 10 is cylindrical in shape, and the constricted portion 13 has a smaller radial dimension relative to the housing 10 as a whole.

[0036] In some embodiments, the housing 10 is integrally stamped and stretched. Of course, this is not a limitation.

[0037] In some embodiments, the housing 10 is made of aluminum or steel, but is not limited to this.

[0038] Example 2

[0039] Please see Figures 1 to 8 This utility model discloses a power battery, which includes a core 20, a current collector 30, a housing 10, and a sealing weld 40. The current collector 30 is welded to the full-pole tab at the top of the core 20. The housing 10 includes a side wall 11, which is sleeved on the outside of the core 20 of the power battery. The side wall 11 includes a side wall body 12 and a constricted portion 13 connected to the top of the side wall body 12 and converging inward relative to the side wall body 12. The inner side of the top surface of the constricted portion 13 is recessed downward to form an annular concave platform 130. The outer edge of the current collector 30 overlaps the annular concave platform 130 and is fixed to the constricted portion 13 by laser seam welding. The outer side of the constricted portion 13 forms an inward concave region 14 relative to the outer surface of the side wall body 12. The outer edge of the sealing weld 40 protrudes downward to form an annular protrusion 41, which is accommodated and supported in the inward concave region 14 and fixed by laser welding.

[0040] In this embodiment of the invention, a constricted portion 13 is formed at the top of the side wall 11 of the housing 10. The inner side of the top surface of the constricted portion 13 is recessed downwards to form an annular recessed platform 130. The outer edge of the current collector 30 overlaps with the annular recessed platform 130 and is fixed to the constricted portion 13 by laser seam welding. An inwardly recessed region 14 is formed on the outer surface of the side wall body 12 opposite to the outer surface of the constricted portion 13. The outer edge of the sealing weld 40 protrudes downwards from an annular downward protrusion 41, which is accommodated and supported in the inwardly recessed region 14 and fixed by laser welding. Because the outer edge of the current collector 30 overlaps with the annular recessed platform 130 and is fixed to the constricted portion 13 by laser seam welding, there is no need to use high-power laser penetration welding, effectively reducing laser welding power and effectively avoiding the risk of welding through the housing wall or incomplete welding. Moreover, because the current collector 30 can be welded and fixed to the housing 10, the torque resistance of the cylindrical core 20 is effectively improved, avoiding the risk of battery open circuit. In addition, since the current collector 30 is fixed to the constricted part 13 by laser seam welding, it has a large welding area, which facilitates the high-rate charging and discharging of the power battery and can effectively suppress excessive temperature rise.

[0041] In some embodiments, the constricted portion 13 includes a bent portion 131 and a vertical portion 132. The lower end of the bent portion 131 is connected to the sidewall body 12, and the upper end of the bent portion 131 is connected to the lower end of the vertical portion 132. The inner side of the top surface of the vertical portion 132 is recessed downward to form an annular recessed platform 130. Of course, the constricted portion 13 is not limited to including the bent portion 131 and the vertical portion 132.

[0042] Specifically, the concave region 14 includes a vertical wall 141 and a sloping wall 142. The lower end of the vertical wall 141 is connected to the upper end of the sloping wall 142. The lower end of the sloping wall 142 is connected to the outer surface of the side wall body 12. The vertical wall 141 and the sloping wall 142 are adapted to the annular downward protrusion 41 of the sealing weld 40, that is, the annular downward protrusion 41 forms a vertical side surface 411 and a sloping surface 412 that are adapted to it.

[0043] More specifically, the sloping wall 142 is an integrally concave curved surface that smoothly connects to the vertical wall 141. Correspondingly, the sloping surface 412 of the annular convex 41 is an integrally convex curved surface.

[0044] In some embodiments, the recessed region 14 includes a sloping wall 142 adapted to the annular protrusion 41 of the sealing sheet 40, specifically a curved surface that is integrally recessed. Of course, the recessed region 14 is not limited to including the sloping wall 142; for example, its bottom may also have an overlapping platform surface for the annular protrusion 41 of the sealing sheet 40 to overlap.

[0045] In some embodiments, the housing 10 is cylindrical in shape, and the constricted portion 13 has a smaller radial dimension relative to the housing 10 as a whole.

[0046] In some embodiments, the housing 10 is integrally stamped and stretched. Of course, this is not a limitation.

[0047] In some embodiments, the housing 10 is made of aluminum or steel, but is not limited to this.

[0048] In some embodiments, the sealing sheet 40 may be provided with a liquid injection hole and / or an explosion-proof valve, etc.

[0049] To facilitate understanding of this utility model, the assembly process of the power battery in the accompanying drawings is described below:

[0050] First, weld the current collector 30 to the full-pole tab at the top of the core 20.

[0051] Next, the core 20 is inserted into the housing 10, and the outer edge of the collector plate 30 overlaps the annular recessed platform 130 of the housing 10. The collector plate 30 is fixed to the constricted part 13 by laser welding.

[0052] Next, the sealing sheet 40 is assembled on the open end of the housing 10, that is, the end with the constricted portion 13, wherein the annular protrusion 41 is placed in the concave area 14 and fits against the vertical wall surface 141 and the sloping wall surface 142, and the sealing sheet 40 and the housing 10 are sealed and fixedly connected by laser welding.

[0053] The above-disclosed examples are merely preferred embodiments of the present utility model, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model are still within the scope of the present utility model.

Claims

1. A casing for a power battery, characterized in that, The housing includes a sidewall for fitting around the outer side of the power battery core. The sidewall includes a sidewall body and a constricted portion connected to the top of the sidewall body and tapering inward relative to the sidewall body. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The annular concave platform is used for the outer edge of the current collector to overlap. The outer side of the constricted portion forms an inward concave region relative to the outer surface of the sidewall body. The inward concave region is used to accommodate and support the annular downward protrusion of the sealing weldment.

2. The casing of the power battery according to claim 1, characterized in that, The constricted portion includes a bent portion and a vertical portion. The lower end of the bent portion is connected to the main side wall, and the upper end of the bent portion is connected to the lower end of the vertical portion. The inner side of the top surface of the vertical portion is recessed downward to form the annular concave platform.

3. The housing of the power battery according to claim 2, characterized in that, The recessed region includes a vertical wall and a sloping wall. The lower end of the vertical wall is connected to the upper end of the sloping wall, and the lower end of the sloping wall is connected to the outer surface of the sidewall body. The vertical wall and the sloping wall are configured to fit the annular downward protrusion of the sealing weld.

4. The casing of the power battery according to claim 1, characterized in that, The concave region includes a sloping wall surface or an overlapping platform surface that is adapted to the annular downward protrusion of the sealing sheet.

5. The casing of the power battery according to claim 1, characterized in that, The shell is formed by integral stamping and stretching.

6. The casing of the power battery according to claim 1, characterized in that, The shell is cylindrical in shape, and the constricted portion has a smaller radial dimension relative to the overall shell.

7. A power battery, characterized in that, The power battery includes a core, a current collector, a casing, and a sealing strip. The current collector is welded to the tab at the top of the core. The casing includes a sidewall that is fitted over the outside of the core. The sidewall includes a main body and a constricted portion connected to the top of the main body and tapering inward relative to the main body. The inner side of the top surface of the constricted portion is recessed downward to form an annular concave platform. The outer edge of the current collector overlaps the annular concave platform and is fixed to the constricted portion by laser seam welding. The outer side of the constricted portion forms a concave region relative to the outer surface of the main body. The outer edge of the sealing strip protrudes downward from an annular protrusion, which is accommodated and supported in the concave region and fixed by laser welding.

8. The power battery according to claim 7, characterized in that, The constricted portion includes a bent portion and a vertical portion. The lower end of the bent portion is connected to the main side wall, and the upper end of the bent portion is connected to the lower end of the vertical portion. The inner side of the top surface of the vertical portion is recessed downward to form the annular concave platform.

9. The power battery according to claim 8, characterized in that, The concave region includes a vertical wall and a sloping wall. The lower end of the vertical wall is connected to the upper end of the sloping wall, and the lower end of the sloping wall is connected to the outer surface of the side wall body. The vertical wall and the sloping wall are adapted to the annular downward protrusion of the sealing weld.

10. The power battery according to claim 7, characterized in that, The concave region includes a sloping wall surface or an overlapping platform surface that is adapted to the annular downward protrusion of the sealing sheet.

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