Housing components for power batteries and power batteries

Abstract

This application discloses a housing assembly for a power battery and a power battery. The housing assembly includes a housing, a sealing pin, a sealing element, and a retaining ring. A sealing pin groove is formed on the upper surface of the housing, and a pressure relief through hole is eccentrically provided on the bottom wall of the sealing pin groove. The sealing pin is rotatably disposed in the sealing pin groove and has an exhaust through hole. A sealing element groove is recessed on the bottom wall of the sealing pin, and the top wall of the sealing element groove includes a first region and a second region. The sealing element is assembled in the sealing element groove. The portion of the sealing element corresponding to the first region has a first compression ratio, and the portion of the sealing element corresponding to the second region has a second compression ratio, wherein the first compression ratio is less than the second compression ratio. Rotation of the sealing pin allows the portion of the sealing element with the first compression ratio to move to cover the pressure relief through hole and allow the pressure relief gas to flow from the pressure relief through hole to the exhaust through hole, and also allows the portion of the sealing element with the second compression ratio to move to cover the pressure relief through hole. This application provides a switching mechanism for pressure relief and pressure prevention in the power battery.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a housing assembly for a power battery 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). At the same time, more and more manufacturers are exploring bottom-through welding technology to address the needs of fast-charging travel. However, the following common problems exist:

[0003] 1. During the cyclic charging and discharging process of cylindrical power batteries, the positive / negative electrode material system will gradually generate gas, or the internal pressure will gradually increase under high-rate charging and discharging / high-temperature conditions, which may cause the battery to deform or pose a safety risk to the battery, ultimately affecting the battery life.

[0004] 2. As people demand longer driving range from power batteries, many battery manufacturers have begun to explore / introduce positive / negative electrode material systems that produce more gas but have higher energy density. However, the greater the gas production of the battery, the more new safety risks will arise.

[0005] 3. If the existing pressure relief structure is directly introduced into the existing cylindrical power battery structure for venting and pressure relief, the internal pressure cannot rise due to air leakage, which will prevent the explosion-proof valve from opening. Summary of the Invention

[0006] The purpose of this application is to provide a housing and a power battery for a power battery, which can solve at least one of the technical problems mentioned in the background.

[0007] To achieve the above objectives, this application provides a housing assembly for a power battery. The housing assembly includes a housing, a rotatable sealing pin, a sealing element, and a retaining ring. A sealing pin groove is formed on the upper surface of the housing, and a pressure relief hole is eccentrically provided on the bottom wall of the sealing pin groove. The sealing pin is rotatably disposed in the sealing pin groove and has a through-hole extending vertically. A sealing element groove is formed on the bottom wall of the sealing pin, with the top wall of the sealing element groove including a first region and a second region, the first region being higher than the second region. The sealing element is assembled in the sealing element groove and pressed against the top wall of the sealing element groove and the bottom wall of the sealing pin groove. The sealing element has a first compression ratio for the portion corresponding to the first region and a second compression ratio for the portion corresponding to the second region, wherein the first compression ratio is less than the second compression ratio; the outer side of the fixing ring is fixedly connected to the sidewall of the sealing pin groove, and the inner side of the fixing ring limits the sealing pin in the vertical and radial directions and allows the sealing pin to rotate along it; the rotation of the sealing pin enables the portion of the sealing element with the first compression ratio to move to cover the pressure relief through hole and the sealing element to allow pressure relief gas to flow from the pressure relief through hole to the exhaust through hole, and enables the portion of the sealing element with the second compression ratio to move to cover the pressure relief through hole.

[0008] Optionally, the top wall of the sealing groove is divided into a first region, a second region, and a third region smoothly connected between the first region and the second region. The first region and the second region are planes parallel to the bottom wall of the sealing pin groove, and the third region is a smooth curved surface.

[0009] Optionally, the sealing element is a sealing ring, and an anti-rotation limiting protrusion is formed in the middle of the groove of the sealing element. The sealing ring is tightly fitted on the anti-rotation limiting protrusion, and the exhaust hole is formed at the anti-rotation limiting protrusion.

[0010] Optionally, the bottom outer periphery of the sealing nail is provided with an annular sliding protrusion, the bottom of which is in smooth contact with the bottom wall of the sealing nail groove.

[0011] Optionally, the sliding protrusion contacts the bottom wall line of the sealing pin groove.

[0012] Optionally, the upper surface of the sealing pin is provided with a pointer mark, and the upper surface of the housing is provided with a first state mark and a second state mark near the groove of the sealing pin. The first state mark and the second state mark are located at different positions in the rotation direction of the sealing pin. When the sealing pin rotates to the point where the pointer mark is aligned with the first state mark, the portion of the sealing member with the first compression ratio moves to cover the pressure relief through hole and the sealing member allows the pressure relief gas to flow from the pressure relief through hole to the exhaust through hole. When the sealing pin rotates to the point where the pointer mark is aligned with the second state mark, the portion of the sealing member with the second compression ratio moves to cover the pressure relief through hole.

[0013] Optionally, the sidewall of the sealing pin forms a first inverted conical surface, and the inner sidewall of the fixing ring forms a second inverted conical surface adapted to the first inverted conical surface. The first inverted conical surface has a plurality of hemispherical first grooves distributed along its circumference, and a plurality of hemispherical grooves distributed along its circumference. Hard spheres are respectively fitted into the plurality of hemispherical grooves. The second inverted conical surface is provided with an annular groove with a semi-circular cross-section adapted to the hard spheres. When the fixing ring is assembled into the groove of the sealing pin, the plurality of hard spheres and the annular groove are fitted and installed, and the plurality of hard spheres press and limit the sealing pin, thereby locking the compression ratio of the seal.

[0014] Optionally, a raised boss is provided on the outer edge of the bottom wall of the sealing nail groove, and the lower surface of the fixing ring is attached to the raised boss.

[0015] Optionally, the sidewall of the sealing pin groove and the outer sidewall of the fixing ring are matching conical surfaces.

[0016] To achieve the above objectives, this application also provides a power battery, including the housing assembly for the power battery as described above.

[0017] When the housing assembly of this application is used in a power battery, and the internal pressure is high due to excessive internal gas production during long-term cycling, rotating the sealing pin can move the portion of the seal with a first compressibility to cover the pressure relief hole. At this time, the seal allows the depressurized gas inside the power battery to flow from the pressure relief hole to the exhaust hole. After depressurization is complete, rotating the sealing pin can move the portion of the seal with a second compressibility to cover the pressure relief hole, thus achieving pressure stabilization of the power battery and re-establishing a high-compression-ratio seal. This application effectively addresses the problem of increased internal pressure caused by slow gas production in the power battery, enables switching between pressure relief and pressure stabilization, extends battery life, and improves battery safety. Attached Figure Description

[0018] Figure 1This is a three-dimensional structural diagram of the power battery according to an embodiment of this application.

[0019] Figure 2 yes Figure 1 Enlarged view of part A in the middle.

[0020] Figure 3 This is a cross-sectional schematic diagram of a partial structure of the power battery according to an embodiment of this application.

[0021] Figure 4 This is a cross-sectional structural schematic diagram of the power battery from another perspective in an embodiment of this application.

[0022] Figure 5 yes Figure 4 Enlarged view of section B in the middle.

[0023] Figure 6 This is a partial structural schematic diagram of the shell according to an embodiment of this application.

[0024] Figure 7 This is a cross-sectional schematic diagram of a partial structure of the shell in an embodiment of this application.

[0025] Figure 8 This is a three-dimensional structural diagram of the sealing nail according to an embodiment of this application.

[0026] Figure 9 This is a three-dimensional structural schematic diagram of the sealing nail from another perspective of an embodiment of this application.

[0027] Figure 10 This is a three-dimensional structural diagram of the sealing ring in a compressed state according to an embodiment of this application.

[0028] Figure 11 This is a three-dimensional structural diagram of the fixing ring according to an embodiment of this application.

[0029] Figure 12 This is a cross-sectional structural diagram of the fixing ring according to an embodiment of this application. Detailed Implementation

[0030] To illustrate the technical content, structural features, and effects of this application in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application 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 application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] Please see Figures 1 to 12This application discloses a housing assembly for a power battery. The housing assembly includes a housing 10, a rotatable sealing pin 20, a sealing element 30, and a retaining ring 40. A sealing pin groove 11 is formed on the upper surface of the housing 10, and a pressure relief hole 12 is eccentrically provided on the bottom wall of the sealing pin groove 11. The sealing pin 20 is rotatably disposed in the sealing pin groove 11, and a vertically penetrating vent hole 21 is provided on the sealing pin 20. A sealing element groove 22 is recessed upward on the bottom wall of the sealing pin 20. The top wall of the sealing element groove 22 includes a first region 221 and a second region 222, with the first region 221 being higher than the second region 222. The sealing element 30 is assembled in the sealing element groove 22 and pressed against the top wall of the sealing element groove 22 and the bottom wall of the sealing pin groove 11. Between them, the portion of the seal 30 corresponding to the first region 221 has a first compression ratio, and the portion of the seal 30 corresponding to the second region 222 has a second compression ratio, the first compression ratio being less than the second compression ratio; the outer side of the fixing ring 40 is fixedly connected to the side wall of the sealing pin groove 11, the inner side of the fixing ring 40 limits the sealing pin 20 in the vertical and radial directions and allows the sealing pin 20 to rotate along it, the rotation of the sealing pin 20 enables the portion of the seal 30 with the first compression ratio (corresponding to the first region 221) to move to cover the pressure relief through hole 12 and the seal 30 to allow the pressure relief gas to flow from the pressure relief through hole 12 to the exhaust through hole 21 and enable the portion of the seal 30 with the second compression ratio (corresponding to the second region 222) to move to cover the pressure relief through hole 12.

[0033] It is understandable that when the portion with the first compression ratio covers the pressure relief hole 12, it can prevent external air from entering the power battery, that is, it can block the free flow of atmospheric pressure air. The approximate values ​​for the first and second compression ratios can be set as needed by adjusting the height of the first region 221 and the second region 222, the thickness of the seal 30, etc. For example, the first compression ratio can be such that when the accumulated gas pressure inside the power battery reaches a certain value, it can break through the obstruction of the portion of the seal 30 with the first compression ratio and flow out to the exhaust hole 21. The second compression ratio, it is understood, needs to be large enough to reliably prevent high-pressure gas from escaping after long-term cycling of the power battery. The pressure relief gas can be gas with a pressure exceeding a certain value.

[0034] Combination Figure 1 Specifically, the thickness of the portion of the seal 30 corresponding to the first region 221 after compression is T, and the compression rate is preferably 3% to 9%. The thickness of the portion of the seal 30 corresponding to the second region 222 after compression is t, and the compression rate is preferably 25% to 35%.

[0035] When the housing assembly of this application is used in a power battery, and the internal pressure is high due to excessive internal gas production during long-term cycling, rotating the sealing pin 20 can move the portion of the sealing member 30 with a first compression ratio to cover the pressure relief hole 12. At this time, the sealing member 30 allows the depressurized gas in the power battery to flow from the pressure relief hole 12 to the exhaust hole 21. After depressurization, rotating the sealing pin 20 can move the portion of the sealing member 30 with a second compression ratio to cover the pressure relief hole 12, thereby achieving pressure relief of the power battery and re-establishing a high compression ratio seal. This application can effectively eliminate the problem of increased internal pressure caused by slow gas production in the power battery, realize the switching between pressure relief and pressure relief of the power battery (preventing the explosion-proof valve from failing to open), extend the life of the power battery, and improve the safety of the power battery.

[0036] In some embodiments, the top wall of the sealing groove 22 is divided into a first region 221, a second region 222, and a third region 223 smoothly connected between the first region 221 and the second region 222. The first region 221 and the second region 222 are planes parallel to the bottom wall of the sealing pin groove 11, and the third region 223 is a smooth curved surface. This technique facilitates the reliable implementation of the aforementioned manual pressure relief and pressure-stopping structure. However, it is not limited to this.

[0037] In some embodiments, the seal 30 is a sealing ring 30.

[0038] Specifically, an anti-rotation limiting protrusion 23 is formed in the middle of the sealing groove 22, the sealing ring 30 is tightly fitted on the anti-rotation limiting protrusion 23, and the vent hole 21 is formed at the anti-rotation limiting protrusion 23. Through the cooperation of the anti-rotation limiting protrusion 23 and the sealing ring 30, relative rotation between the sealing ring 30 and the sealing pin 20 can be prevented during rotation, ensuring reliability.

[0039] Specifically, the anti-rotation limiting protrusion 23 is square, but not limited to this.

[0040] In some embodiments, the bottom outer periphery of the sealing pin 20 is provided with a downwardly protruding annular sliding protrusion 24, the bottom of which smoothly contacts the bottom wall of the sealing pin groove 11. Because the bottom of the sealing pin 20 has an annular sliding protrusion 24 and the sliding protrusion 24 smoothly contacts the bottom wall of the sealing pin groove 11, the sealing pin 20 can be slidably and rotatably mounted on the bottom wall of the sealing pin groove 11 via the sliding protrusion 24. This facilitates reliable assembly of the sealing pin 20 and reduces the difficulty of rotating the sealing pin 20.

[0041] Specifically, the sliding protrusion 24 contacts the bottom wall of the sealing nail groove 11, which facilitates the rotation of the sealing nail 20 on the bottom wall of the sealing nail groove 11.

[0042] In a specific example, the surface of the slip convex 24 has a radial cross-section that is arc-shaped.

[0043] In some embodiments, the upper surface of the sealing pin 20 is provided with a pointer mark 25, and the upper surface of the housing 10 is provided with a first state mark 13 and a second state mark 14 near the sealing pin groove 11. The first state mark 13 and the second state mark 14 are located at different positions in the rotation direction of the sealing pin 20. When the sealing pin 20 rotates to the point where the pointer mark 25 is aligned with the first state mark 13, the portion of the sealing member 30 with a first compression ratio moves to cover the pressure relief through hole 12 and the sealing member 30 allows the pressure relief gas to flow from the pressure relief through hole 12 to the exhaust through hole 21. When the sealing pin 20 rotates to the point where the pointer mark 25 is aligned with the second state mark 14, the portion of the sealing member 30 with a second compression ratio moves to cover the pressure relief through hole 12. By setting pointer 25 and first state mark 13 and second state mark 14, when the sealing pin 20 rotates until pointer 25 aligns with first state mark 13, it can be determined that the portion of the sealing member 30 with the first compression ratio has moved to cover the pressure relief hole 12. The internal gas can flow from the pressure relief hole 12 to the exhaust hole 21 and be discharged outward through the exhaust hole 21. After pressure relief is completed, when the sealing pin 20 rotates until pointer 25 aligns with second state mark 14, it can be determined that the portion of the sealing member 30 with the second compression ratio has moved to cover the pressure relief hole 12. Pressure can be stopped inside the power battery to achieve a strong seal.

[0044] Specifically, the pointer marking 25 may take the form of a grooved groove, but is not limited to this. For ease of identification, the pointer marking 25 may be colored, etc.

[0045] Specifically, the first state identifier 13 and the second state identifier 14 can be set to a concave dot form, but are not limited to this. For ease of identification, the first state identifier 13 and the second state identifier 14 can be colored, for example, the first state identifier 13 can be set to red and the second state identifier 14 can be set to blue.

[0046] Specifically, the first state identifier 13 and the second state identifier 14 are set roughly opposite to each other, but are not limited to this.

[0047] In some embodiments, the sidewall of the sealing nail 20 forms a first inverted conical surface 26, and the inner sidewall of the fixing ring 40 forms a second inverted conical surface 41 adapted to the first inverted conical surface 26. The first inverted conical surface 26 has a plurality of hemispherical grooves 261 distributed around its circumference, and a hard ball 60 is adapted to be installed in each of the plurality of hemispherical grooves 261. The second inverted conical surface 41 is provided with an annular groove 411 with a semi-circular cross section adapted to the hard ball 60. When the fixing ring 40 is assembled in the sealing nail groove 11, the plurality of hard balls 60 and the annular groove 411 are adapted to be installed, and the plurality of hard balls 60 press and limit the sealing nail 20, and the compression ratio of the sealing member 30 is locked. By using the second inverted conical surface 41 of the retaining ring 40, the first inverted conical surface 26 of the sealing pin 20, and a plurality of hard spheres 60, the sealing pin 20 can be limited in the vertical and radial directions (i.e., it cannot move in the vertical and radial directions), the sealing pin 20 can be rotated along the second inverted conical surface 41, and the compression ratio of the sealing element 30 can be locked.

[0048] Specifically, the hard sphere 60 can be a ceramic sphere, a metal sphere, etc., and this application does not impose any specific restrictions on it.

[0049] Specifically, a boss 111 is provided on the outer edge of the bottom wall of the sealing nail groove 11. The lower surface of the fixing ring 40 is attached to the boss 111. That is, after the fixing ring 40 is assembled, the fixing ring 40 is supported on the boss 111.

[0050] Specifically, the upper surface of the retaining ring 40 is a horizontal plane that is flush with or slightly lower than the upper surface of the housing 10. That is, after the retaining ring 40 is assembled, the upper surface of the retaining ring 40 is flush with or slightly lower than the upper surface of the housing 10, but it is not limited to this.

[0051] Specifically, the sidewall of the sealing pin groove 11 and the outer sidewall of the fixing ring 40 are matching conical surfaces, but this is not a limitation.

[0052] Specifically, the outer wall of the retaining ring 40 and the outer wall of the sealing pin groove 11 are fixed together by laser welding.

[0053] In some embodiments, the sealing nail 20 may be made of aluminum or steel, but is not limited to these materials.

[0054] In some embodiments, the sealing pin 20 may be integrally stamped / stretched, but is not limited to this.

[0055] In some embodiments, the retaining ring 40 may be made of aluminum or steel, but is not limited to these materials.

[0056] In some embodiments, the retaining ring 40 may be integrally stamped / stretched, but is not limited to this.

[0057] In the example shown in the attached drawings, the housing 10 is the outer casing of the power battery, which is used to fit over the outer side of the core 70. The housing includes a side wall 101 and a bottom 102, where the upper surface of the housing 10 refers to the upper surface (outer surface) of the bottom 102. Of course, the housing 10 is not limited to an outer casing; it can also be a cover for the power battery, in which case the upper surface of the housing 10 is the upper surface (outer surface) of the cover.

[0058] To facilitate understanding of this application, the assembly process of the housing assembly is described below with reference to the examples shown in the accompanying drawings. This should not be construed as a limitation of this application.

[0059] First, install and fix the sealing ring 30 in the sealing groove 22 at the bottom of the sealing nail 20.

[0060] Next, the sealing nail 20 is placed into the sealing nail groove 11, the sealing ring 30 is pressed against the bottom wall of the sealing nail groove 11, and the hard sphere 60 is placed into the hemispherical groove 261 distributed around the sealing nail 20.

[0061] Next, the retaining ring 40 is assembled. The annular groove 411 on the second inverted conical surface 41 is adapted to the exposed part of the hard sphere 60. The retaining ring 40 presses down on the sealing nail 20 through the hard sphere 60 and adjusts the sealing nail 20 in an adaptive position. When the lower surface of the retaining ring 40 is attached to the boss 111, the sealing nail 20 is limited in the vertical and radial directions, so that the sealing ring 30 is compressed downward into place, and the sliding protrusion 24 forms a line contact with the bottom wall of the sealing nail groove 11.

[0062] Next, the outer wall of the retaining ring 40 and the side wall of the sealing pin groove 11 are welded and fixed by laser welding.

[0063] Please combine Figures 1 to 12 This application also discloses a power battery, including the housing assembly for the power battery as described above.

[0064] In this embodiment of the application, when the power battery experiences prolonged cycling and excessive internal gas production leading to high internal pressure, rotating the sealing pin 20 can move the portion of the sealing member 30 with a first compression ratio to cover the pressure relief hole 12. At this time, the sealing member 30 allows gas inside the power battery to flow from the pressure relief hole 12 to the exhaust hole 21. After pressure relief is completed, rotating the sealing pin 20 can move the portion of the sealing member 30 with a second compression ratio to cover the pressure relief hole 12, thus achieving pressure stabilization of the power battery and re-establishing a high compression ratio seal. This application can effectively address the problem of increased internal pressure caused by slow gas production in the power battery, enabling switching between pressure relief and pressure stabilization, extending the power battery's lifespan, and improving its safety.

[0065] The above-disclosed examples are merely preferred embodiments of this application, intended to facilitate understanding and implementation by those skilled in the art. They should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the scope of this application are still within the scope of this application.

Claims

1. A housing assembly for a power battery, characterized in that, The housing assembly includes a housing, a rotatable sealing pin, a sealing element, and a retaining ring. The upper surface of the housing has a sealing pin groove, and the bottom wall of the sealing pin groove has an eccentrically located pressure relief hole. The sealing pin is rotatably disposed in the sealing pin groove and has a through-hole extending vertically. The bottom wall of the sealing pin has an upwardly recessed sealing element groove. The top wall of the sealing element groove includes a first region and a second region, with the first region being higher than the second region. The sealing element is assembled in the sealing element groove and pressed between the top wall of the sealing element groove and the bottom wall of the sealing pin groove. The sealing element corresponds to the first region. A portion of the region has a first compression ratio, and a portion of the seal corresponding to the second region has a second compression ratio, wherein the first compression ratio is less than the second compression ratio; the outer side of the retaining ring is fixedly connected to the sidewall of the sealing pin groove, and the inner side of the retaining ring limits the sealing pin in the vertical and radial directions and allows the sealing pin to rotate thereal; the rotation of the sealing pin enables the portion of the seal with the first compression ratio to move to cover the pressure relief through hole and the seal to allow pressure relief gas to flow from the pressure relief through hole to the exhaust through hole, and enables the portion of the seal with the second compression ratio to move to cover the pressure relief through hole.

2. The housing assembly for a power battery according to claim 1, characterized in that, The top wall of the sealing groove is divided into a first region, a second region, and a third region smoothly connected between the first region and the second region. The first region and the second region are planes parallel to the bottom wall of the sealing pin groove, and the third region is a smooth curved surface.

3. The housing assembly for a power battery according to claim 1, characterized in that, The sealing element is a sealing ring, and an anti-rotation limiting protrusion is formed in the middle of the groove of the sealing element. The sealing ring is tightly fitted on the anti-rotation limiting protrusion, and the exhaust hole is formed at the anti-rotation limiting protrusion.

4. The housing assembly for a power battery according to claim 1, characterized in that, The bottom outer periphery of the sealing nail has a downwardly protruding annular sliding protrusion, the bottom of which is in smooth contact with the bottom wall of the sealing nail groove.

5. The housing assembly for a power battery according to claim 4, characterized in that, The sliding protrusion contacts the bottom wall line of the sealing nail groove.

6. The housing assembly for a power battery according to claim 1, characterized in that, The upper surface of the sealing pin is provided with a pointer mark, and the upper surface of the housing is provided with a first state mark and a second state mark near the groove of the sealing pin. The first state mark and the second state mark are located at different positions in the rotation direction of the sealing pin. When the sealing pin rotates to the point where the pointer mark is aligned with the first state mark, the portion of the sealing member with the first compression ratio moves to cover the pressure relief through hole and the sealing member allows the pressure relief gas to flow from the pressure relief through hole to the exhaust through hole. When the sealing pin rotates to the point where the pointer mark is aligned with the second state mark, the portion of the sealing member with the second compression ratio moves to cover the pressure relief through hole.

7. The housing assembly for a power battery according to claim 1, characterized in that, The sidewall of the sealing pin forms a first inverted conical surface, and the inner sidewall of the fixing ring forms a second inverted conical surface that matches the first inverted conical surface. The first inverted conical surface has a plurality of hemispherical first grooves distributed along its circumference, and a plurality of hemispherical grooves distributed along its circumference. Hard spheres are respectively fitted into the plurality of hemispherical grooves. The second inverted conical surface has an annular groove with a semi-circular cross-section that matches the hard spheres. When the fixing ring is assembled into the groove of the sealing pin, the plurality of hard spheres and the annular groove are fitted together and installed. The plurality of hard spheres press and limit the sealing pin, and the compression ratio of the sealing element is locked.

8. The housing assembly for a power battery according to claim 7, characterized in that, The outer edge of the bottom wall of the sealing nail groove is provided with a raised boss, and the lower surface of the fixing ring is attached to the raised boss.

9. The housing assembly for a power battery according to claim 7 or 8, characterized in that, The sidewall of the sealing pin groove and the outer sidewall of the fixing ring are matching conical surfaces.

10. A power battery, characterized in that, Includes the housing assembly for a power battery as described in any one of claims 1 to 9.

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