JP7819306B2 - Cell Top Cover - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to Chinese Patent Application No. 2023111258482, entitled "Cell Top Cover," filed on September 1, 2023; priority to Chinese Patent Application No. 2023111265128, entitled "Under-Plastic Structure of Cell Top Cover and Cell Top Cover," filed on September 1, 2023; and priority to Chinese Patent Application No. 2023223848895, entitled "Under-Plastic Structure of Cell Top Cover and Cell Top Cover," filed on September 1, 2023, the entire disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION
The present application relates to the technical field of energy storage cells, and in particular to cell top covers.

Currently commercially available top covers for energy storage cells include components such as poles, aluminum reflective sheets, and under-plastic. Through-holes are located at the same height in the aluminum reflective sheet and under-plastic to form liquid injection holes, which are fitted with sealing nails. Conventional liquid injection holes are straight and cylindrical, which means that after electrolyte is injected into the cell, the injection speed through the liquid injection hole is slow and the injection time is long. Furthermore, before liquid injection, a vacuum must be evacuated from the inside of the cell to create negative pressure within the cell. After liquid injection is complete and the sealing nail is attached to the liquid injection hole, the negative pressure can easily push the sealing nail into the cell, affecting the sealing performance of the liquid injection hole and causing electrolyte to leak out of the liquid injection hole, resulting in serious leakage problems.

Therefore, the under-plastic structure of the cell top cover in conventional technology has the problem of slow liquid injection speed and a tendency for liquid to leak.

The present embodiment aims to provide a cell top cover that can increase the liquid injection speed, avoid the problem of liquid leakage, and reduce the erosion strength of the electrolyte against the inside of the cell during liquid injection.

To solve the above technical problems, an embodiment of the present application provides a cell top cover, which includes an aluminum reflective sheet and an under-plastic structure, with the upper side of the under-plastic structure attached to the bottom side of the aluminum reflective sheet. The under-plastic structure includes a first plate body, a second plate body, and an intermediate protrusion located between the first plate body and the second plate body. The intermediate protrusion protrudes from the bottom side of the first plate body and the bottom side of the second plate body. The first plate body is provided with a first electrode post through-hole, and the second plate body is provided with a first liquid injection through-hole and a second electrode post through-hole. The bottom side of the second plate body is provided with a stopper portion protruding from the periphery of the first liquid injection through-hole. The stopper portion has an openwork structure, and the openwork area of the stopper portion is larger than the cross-sectional area of the first liquid injection through-hole.

In some embodiments, the stopper portion includes a side surface and a bottom surface, the side surface continuing to the bottom side of the second plate body and surrounding the periphery of the first liquid injection through-hole, the side surface extending away from the second plate body and continuing to the bottom surface, the side surface having a plurality of evenly spaced diversion holes arranged along its periphery, and the total area of all the diversion holes being greater than the cross-sectional area of the first liquid injection through-hole. In this way, the bottom surface provides an excellent barrier against sealing nails, and the provision of a plurality of diversion holes on the side surface allows the electrolyte injected through the first liquid injection through-hole to quickly disperse and flow out along the periphery of the stopper portion, thereby increasing the liquid injection speed through the first liquid injection through-hole.

In some embodiments, the first plate body and the second plate body are provided with side end protrusions on both sides spaced apart from each other, the side end protrusions protruding from the bottom side of the first plate body and the bottom side of the second plate body, and the side end protrusions are provided with a plurality of holes. This allows the side end protrusions to form an insertion space between the first plate body and the second plate body, respectively, making it easier to insert a jelly roll of the cellular structure into the bottom side of this under-plastic structure and further facilitating attachment between the cell top cover and the cellular structure provided on the bottom side of the cell top cover. The multiple holes in the side end protrusions can reduce the weight of the under-plastic structure, and therefore the weight of the cell top cover.

In some embodiments, the side end protrusions have a frame structure, and are provided with a plurality of reinforcing ribs extending along the length of the under-plastic structure. By configuring the side end protrusions as a frame structure, the weight of the under-plastic structure can be further reduced, and the provision of reinforcing ribs can increase the strength of the under-plastic structure.

In some embodiments, the cell top cover further includes a sealing nail, and the aluminum reflective sheet is provided with a second liquid injection through-hole having the same central axis as the first liquid injection through-hole, the sealing nail is inserted into the second liquid injection through-hole, and the gap between the bottom end of the sealing nail and the bottom of the stopper portion is set to 0.5 mm to 2 mm.

In some embodiments, the second liquid injection through hole is a stepped hole including a first hole segment and a second hole segment, the radial dimension of the first hole segment being larger than the radial dimension of the second hole segment, and the second hole segment being closer to the first liquid injection through hole.

In some embodiments, the cell top cover further includes an explosion-proof valve, and the intermediate protrusion has multiple ventilation holes, the explosion-proof valve being attached to the back surface of the intermediate protrusion and positioned opposite the multiple ventilation holes.

In some embodiments, a locking groove is provided on each side of the intermediate protrusion where it connects to the first plate body and the second plate body, the explosion-proof valve is locked in the locking groove, and the recess depth of the locking groove is smaller than the protruding height of the intermediate protrusion.

In some embodiments, the intermediate protrusion is rectangular, the ventilation holes are rod-shaped and extend along the width of the under-plastic structure, and multiple ventilation holes are uniformly spaced apart from one another on the intermediate protrusion.

In some embodiments, the aluminum reflective sheet has a positive electrode column through-hole, a negative electrode column through-hole, and an explosion-proof through-hole that penetrate the thickness of the aluminum reflective sheet, and the positive electrode column through-hole and the negative electrode column through-hole are respectively located at two different orientations of the explosion-proof through-hole. The aluminum reflective sheet further includes an explosion-proof valve, the explosion-proof valve having opposing upper and lower surfaces, the explosion-proof valve being fixed to the aluminum reflective sheet and covering the explosion-proof through-hole, the upper surface facing the explosion-proof through-hole, and the explosion-proof valve including an explosion serration and a reinforcing rib, the explosion serration being a recess extending from the upper surface to the lower surface, the reinforcing rib being located within a partial area of the recess, and the distance between the reinforcing rib and the negative electrode column through-hole being smaller than the distance between the reinforcing rib and the positive electrode column through-hole.

In some embodiments, the thickness of the explosive notches ranges from 0.1 mm to 0.15 mm.

In some embodiments, the thickness of the reinforcing ribs is greater than the thickness of the explosion notches.

In some embodiments, the thickness of the reinforcing rib ranges from 0.16 mm to 0.25 mm.

In some embodiments, the deployed length of the reinforcing rib is 1/6 or less of the deployed length of the explosive notch.

In some embodiments, the explosion-proof valve further includes an installation marking, the installation marking being located on the underside and adjacent to the reinforcing rib.

In some embodiments, the explosion-proof valve further includes a connecting portion, the connecting portion including a first outer ring portion and a second outer ring portion, the first outer ring portion being disposed around the outer periphery of the explosion indentations and connected to the explosion indentations, the second outer ring portion being disposed around the outer periphery of the first outer ring portion and connected to the first outer ring portion, and wherein the thickness of the first outer ring portion is less than or equal to the thickness of the second outer ring portion.

In some embodiments, the thickness range of the second outer ring portion is 0.3 mm to 0.7 mm.

In some embodiments, the explosion-proof valve further includes a rupture disk, the rupture disk being connected to the inner periphery of the explosion indentations, and the explosion indentations being disposed around the outer periphery of the rupture disk.

In some embodiments, the reinforcing rib and the rupture disk are integrally molded structures.

In the cell top cover of this embodiment, an openwork stopper portion is provided on the bottom side of the first liquid injection through-hole in the under-plastic structure. After electrolyte is injected into the first liquid injection through-hole, the stopper portion divides the electrolyte into multiple streams and injects them into the cell in different directions, significantly reducing interference with the electrolyte caused by the cell's inner wall, thereby increasing the liquid injection speed and shortening the liquid injection time through the first liquid injection through-hole. The stopper portion also acts as a barrier against the sealing nail, preventing it from being pushed into the cell by negative pressure, causing sealing problems and ultimately preventing liquid leakage from the first liquid injection through-hole. Therefore, this under-plastic structure of the cell top cover can increase the liquid injection speed and prevent liquid leakage. Furthermore, because the stopper portion separates the electrolyte into multiple bundles, when each bundle of electrolyte is injected into the cell, the strength of the electrolyte's corrosion of the pole pieces inside the cell is relatively weak, preventing the problem of the electrode material (positive or negative electrode material) at the pole pieces peeling off due to electrolyte corrosion and ensuring that the pole pieces maintain good electrical conductivity.

The cell top cover also includes a sealing nail, and the aluminum reflective sheet is provided with a second liquid injection through-hole having the same central axis as the first liquid injection through-hole. The sealing nail is inserted into the second liquid injection through-hole, and the gap between the bottom end of the sealing nail and the bottom of the stopper portion 1 is set to 0.5 mm to 2 mm. As a result, since the aluminum reflective sheet is provided above the under-plastic structure, providing the second liquid injection through-hole directly above the first liquid injection through-hole contributes to accelerating the electrolyte injection speed.

The second liquid injection through hole is a stepped hole including a first hole segment and a second hole segment, with the radial dimension of the first hole segment being larger than the radial dimension of the second hole segment, and the second hole segment being closer to the first liquid injection through hole. This allows the stepped second liquid injection through hole to also provide a certain blocking effect against the sealing nail, further avoiding sealing problems with the liquid injection through hole.

The cell top cover further includes an explosion-proof valve, with multiple vent holes provided in the intermediate protrusion. The explosion-proof valve is attached to the back surface of the intermediate protrusion and is installed opposite the multiple vent holes. As a result, the intermediate protrusion protrudes downward from the explosion-proof valve, ensuring sufficient gas discharge space between the under-plastic structure and the explosion-proof valve. The provision of vent holes in the intermediate protrusion not only serves to discharge gas, but also filters the rupture disk of the explosion-proof valve in the event of an explosion, preventing the rupture disk of the explosion-proof valve from falling into the cell structure at the bottom of the under-plastic structure.

In addition, a locking groove is provided on each side of the intermediate protrusion where it connects to the first plate body and the second plate body, and the explosion-proof valve is locked into the locking groove, with the recess depth of the locking groove being smaller than the protruding height of the intermediate protrusion. This allows the explosion-proof valve to be attached to the back surface of the intermediate protrusion with a simple structure, making the attachment structure between the explosion-proof valve and the intermediate protrusion easier.

The intermediate protrusion is rectangular, the ventilation hole is rod-shaped and extends along the width of the under-plastic structure, and multiple ventilation holes are evenly spaced apart on the intermediate protrusion. This arrangement ensures a sufficient gas discharge area for the explosion-proof valve, allowing the intermediate protrusion to perform better gas conduction.

One or more embodiments are illustratively illustrated in the accompanying drawing figures, but these illustrative illustrations are not intended to be limiting of the embodiments, and in the accompanying drawings, like reference numerals refer to like parts, and unless otherwise noted, the drawings are not limited to scale.
FIG. 1 is a diagram showing the configuration of the under-plastic structure of the cell top cover provided in some embodiments of the present application. FIG. 2 is a diagram showing a top view of the under-plastic structure of the cell top cover provided in some embodiments of the present application. FIG. 3 is a cross-sectional view of the configuration of FIG. FIG. 4 is a diagram showing a cross-sectional view of the under-plastic structure and aluminum reflecting sheet of the cell top cover provided in some embodiments of the present application. FIG. 5 is an exploded view of a cell top cover provided in some embodiments of the present application. FIG. 6 is an assembly diagram of a cell top cover provided in some embodiments of the present application. FIG. 7 shows a combination configuration of the cell top cover provided in some embodiments of the present application. FIG. 8 is a perspective half-sectional view of an aluminum reflector sheet provided in some embodiments of the present application. FIG. 9 is a diagram illustrating the configuration of an explosion-proof valve provided in some embodiments of the present application. FIG. 10 illustrates another explosion-proof valve configuration provided in some embodiments of the present application. FIG. 11 is a diagram illustrating another explosion-proof valve configuration provided in some embodiments of the present application. FIG. 12 illustrates another explosion-proof valve configuration provided in some embodiments of the present application. FIG. 13 is a diagram showing a front view of another explosion-proof valve provided in some embodiments of the present application. FIG. 14 illustrates another explosion-proof valve configuration provided in some embodiments of the present application. FIG. 15 illustrates another explosion-proof valve configuration provided in some embodiments of the present application. FIG. 16 is a diagram showing a front view of another explosion-proof valve provided in some embodiments of the present application. FIG. 17 shows another combination configuration of the cell top cover provided in some embodiments of the present application. FIG. 18 is a structural perspective view of the protection sheet provided in some embodiments of the present application. FIG. 19 is a structural perspective view of a gasket provided in some embodiments of the present application. FIG. 20 is a diagram showing the structure of the protection sheet body provided in some embodiments of the present application. FIG. 21 is an exploded view provided in some embodiments of the present application. FIG. 22 is an assembly diagram of the cell top cover and cell housing provided in some embodiments of the present application.

In order to clarify the objectives, technical ideas, and advantages of the embodiments of the present invention, each embodiment of the present invention will be described in detail below with reference to the drawings. However, while many technical details are described in each embodiment of the present invention to help readers better understand the present invention, it will be obvious to those skilled in the art that the technical solutions protected by the present invention can be realized without these technical details and the various changes and modifications based on the following embodiments.

In the embodiments of the present invention, the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" are orientations or positional relationships indicated based on the drawings. These terms are primarily intended to better explain the present invention and its embodiments, and are not intended to limit the indicated devices, units, or components to have a specific orientation or to be configured and operated in a specific orientation.

In addition, some of the above terms can be used to express meanings other than orientation or positional relationships. For example, the term "up" can also be used to express a dependency or connection relationship in some cases. Those skilled in the art will be able to understand the specific meanings of these terms in the present invention depending on the specific circumstances.

Furthermore, the terms "attach," "install," "provided," "established," "connected," and "coupled" should be understood in a broad sense. For example, they may refer to a fixed connection, a removable connection, or an integral structure; a mechanical connection, an electrical connection; a direct connection, an indirect connection via an intermediate medium, or an internal connection between two devices, units, or components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

Furthermore, terms such as "first," "second," etc. are primarily used to distinguish between different devices, units, or components (which may be of the same or different specific type and configuration), and are not intended to state or imply the relative importance or quantity of the designated devices, units, or components. Unless otherwise specified, "plurality" means two or more.

In an embodiment of the present application, an under-plastic structure of a cell top cover is provided. As shown in FIGS. 1 to 3 , the under-plastic structure of the cell top cover includes a first plate body 110, a second plate body 120, and an intermediate protrusion 130 located between the first plate body 110 and the second plate body 120. The intermediate protrusion 130 protrudes from the bottom side of the first plate body 110 and the bottom side of the second plate body 120. The first plate body 110 is provided with a first electrode post through-hole 111, and the second plate body 120 is provided with a first liquid injection through-hole 121 and a second electrode post through-hole 122. The bottom side of the second plate body 120 is provided with a stopper portion 140 protruding from the periphery of the first liquid injection through-hole 121. The stopper portion 140 has an openwork structure, and the openwork area of the stopper portion 140 is larger than the cross-sectional area of the first liquid injection through-hole 121.

In this embodiment, the electrolyte for the cell is injected into the interior of the cell through the first liquid injection through-hole 121. Because an openwork stopper portion 140 is provided at the bottom of the first liquid injection through-hole 121, the electrolyte enters the first liquid injection through-hole 121 and then disperses through the openwork area of the stopper portion 140 before being injected into the interior of the cell. Therefore, the stopper portion 140 can change the flow direction of the electrolyte injected into the interior of the cell through the first liquid injection through-hole 121, and can also divide the electrolyte into multiple streams that are injected into the interior of the cell in different directions, significantly reducing the obstruction of the electrolyte from the cell's inner wall. This in turn increases the liquid injection speed through the first liquid injection through-hole 121 and shortens the liquid injection time. The area of the openwork region of the stopper portion 140 is set larger than the cross-sectional area of the first liquid injection through-hole 121, ensuring that the electrolyte injected through the first liquid injection through-hole 121 can immediately flow out of the stopper portion 140. This prevents the stopper portion 140 from interfering with the electrolyte injected into the first liquid injection through-hole 121 and thus reduces the influence of the stopper portion 140 on the liquid injection speed. Furthermore, after liquid injection is completed, the first liquid injection through-hole 121 must be sealed with the sealing nail 30. When negative pressure is created inside the cell, the stopper portion 140 acts as a barrier against the sealing nail 30, preventing the sealing nail 30 from being pushed into the cell by the negative pressure, causing sealing problems and ultimately preventing liquid leakage from the first liquid injection through-hole 121. Therefore, this under-plastic structure of the cell top cover can increase the liquid injection speed and prevent liquid leakage. Furthermore, the provision of the intermediate protrusion 130 increases the overall strength of the under-plastic structure 10.

Specifically, the stopper portion 140 includes a side surface 141 and a bottom surface 142. The side surface 141 is continuous with the bottom side of the second plate body 120 and surrounds the periphery of the first liquid injection through-hole 121. The side surface 141 extends away from the second plate body 120 and is continuous with the bottom surface 142. A plurality of diversion holes 1411 are uniformly spaced along the periphery of the side surface 141, and the total area of all the diversion holes 1411 is greater than the cross-sectional area of the first liquid injection through-hole 121. In this way, the bottom surface 142 effectively prevents the sealing nail 30 from leaking. The provision of a plurality of diversion holes 1411 on the side surface 141 allows the electrolyte injected through the first liquid injection through-hole 121 to quickly disperse and flow out along the periphery of the stopper portion 140, thereby increasing the liquid injection speed of the first liquid injection through-hole 121.

More specifically, the stopper portion 140 may be bowl-shaped, can-shaped, or the like, and the thickness of the stopper portion 140 is set to approximately 0.8 mm, preferably 0.8 mm. The shape of the diversion hole 1411 may be trapezoidal, rectangular, triangular, or the like, and can be set specifically according to the shape of the side surface 141. In this embodiment, the stopper portion 140 is bowl-shaped, and the diversion hole 1411 is a trapezoidal hole. A through hole may also be provided in the bottom surface 142 of the stopper portion 140, and the radial dimension of the through hole must be smaller than the minimum radial dimension of the sealing nail 30.

The first plate body 110, the second plate body 120, and the intermediate protrusion 130, and the stopper portion 140 and the second plate body 120 may be connected by adhesive, fastening, or other methods, or may be integrally molded. Specifically, these may be installed according to actual design and usage needs. This embodiment does not limit this. The first electrode post through-hole 111 and the second electrode post through-hole 122 are used to allow the positive electrode post 50 and the negative electrode post 60 to pass through the under-plastic structure 10, respectively. The first liquid injection through-hole 121 may be provided in the first plate body 110. In this case, the stopper portion 140 is provided on the bottom side of the first plate body 110 and protrudes from the periphery of the first liquid injection through-hole 121 in a direction away from the first plate body 110.

Furthermore, side end protrusions 150 are provided on both mutually spaced sides of the first plate body 110 and the second plate body 120. The side end protrusions 150 protrude from the bottom side of the first plate body 110 and the bottom side of the second plate body 120, and each side end protrusion 150 has a plurality of holes 151. As a result, the side end protrusions 150 form an insertion space between the first plate body 110 and the second plate body 120, respectively, making it easier to insert a cellular jelly roll into the bottom side of this under-plastic structure 10 and further facilitating attachment between the cell top cover and the cell structure provided on the bottom side of the cell top cover. The plurality of holes 151 in the side end protrusions 150 reduces the weight of the under-plastic structure 10, which in turn reduces the weight of the cell top cover.

Specifically, the side end protrusions 150 have a frame structure, and are provided with a plurality of reinforcing ribs 152 extending along the longitudinal direction X of the under-plastic structure 10. By configuring the side end protrusions 150 as a frame structure, the weight of the under-plastic structure 10 can be further reduced, and the provision of the reinforcing ribs 152 can increase the strength of the under-plastic structure 10.

More specifically, the number of holes 151 and reinforcing ribs 152 in the side end protrusion 150 may be two, three, four, etc., respectively, and the number of holes 151 may be greater than the number of reinforcing ribs 152. Specific settings can be made according to actual needs. This embodiment does not specifically limit this.

An embodiment of the present application further provides a cell top cover. As shown in Figures 4 to 6, the cell top cover includes an aluminum reflective sheet 20 and an under-plastic structure of any of the above-mentioned cell top covers. The upper side of the under-plastic structure 10 is located on the bottom side of the aluminum reflective sheet 20. A seal ring 70 is located between the under-plastic structure 10 and the aluminum reflective sheet 20, and the seal ring 70 is fitted onto the pole.

In the cell top cover of this embodiment, an openwork stopper portion 140 is provided at the bottom of the first liquid injection through-hole 121 of the under-plastic structure 10. After the electrolyte is injected into the first liquid injection through-hole 121, the stopper portion 140 divides the electrolyte into multiple streams and injects them in different directions into the cell, significantly reducing the obstruction of the electrolyte from the cell's inner wall, thereby improving the liquid injection speed through the first liquid injection through-hole 121 and shortening the liquid injection time. Furthermore, the stopper portion 140 acts as a barrier against the sealing nail 30, preventing the sealing nail 30 from being pushed into the cell by negative pressure, causing sealing problems and ultimately preventing liquid leakage from the first liquid injection through-hole 121. Therefore, this under-plastic structure of the cell top cover can increase the liquid injection speed and prevent liquid leakage.

Furthermore, in conventional technology, liquid injection holes are generally straight, cylindrical holes. When electrolyte is injected into a cell through a straight, cylindrical hole, it can significantly corrode the pole pieces inside the cell, posing a risk of peeling off the positive or negative electrode material in the pole pieces. In contrast, in the embodiment of the present application, the stopper portion 140 divides the electrolyte into multiple bundles and injects each into the cell in a different direction, thereby improving the liquid injection speed. Furthermore, because the electrolyte is divided into multiple bundles, the strength of corrosion of the electrolyte on the pole pieces inside the cell is relatively weaker when injected into the cell. This reduces the risk of peeling off the positive or negative electrode material due to significant corrosion of the pole pieces by the electrolyte, and ensures that the pole pieces maintain good performance even after the electrolyte is injected into the cell.

The cell top cover further includes a sealing nail 30, and the aluminum reflective sheet 20 is provided with a second liquid injection through-hole 210 having the same central axis as the first liquid injection through-hole 121. The sealing nail 30 is inserted into the second liquid injection through-hole 210, and the gap between the bottom end of the sealing nail 30 and the bottom of the stopper portion 140 is set to 0.5 mm to 2 mm, and may be, for example, 0.5 mm, 0.9 mm, 1.6 mm, or 2 mm. As a result, since the aluminum reflective sheet 20 is provided above the under-plastic structure 10, providing the second liquid injection through-hole 210 directly above the first liquid injection through-hole 121 contributes to accelerating the injection speed of the electrolyte.

Specifically, the second liquid injection through-hole 210 is a stepped hole including a first hole segment 211 and a second hole segment 212, where the radial dimension of the first hole segment 211 is larger than the radial dimension of the second hole segment 212, and the second hole segment 212 is closer to the first liquid injection through-hole 121. This allows the stepped second liquid injection through-hole 210 to also have a certain blocking effect on the sealing nail 30, further avoiding sealing problems with the liquid injection through-hole.

The aluminum reflective sheet 20 is further provided with a third electrode post through hole 220 and a fourth electrode post through hole 230, which have the same central axes as the first electrode post through hole 111 and the second electrode post through hole 122, respectively. The positive electrode post 50 passes through the first electrode post through hole 111 and the third electrode post through hole 220 in sequence and extends to the outside of the cell top cover, and the negative electrode post 60 passes through the second electrode post through hole 122 and the fourth electrode post through hole 230 in sequence and extends to the outside of the cell top cover.

The cell top cover further includes an explosion-proof valve 40, with multiple vent holes 131 provided in the middle protrusion 130. The explosion-proof valve 40 is attached to the back surface of the middle protrusion 130 and is installed opposite the multiple vent holes 131. As a result, the middle protrusion 130 protrudes downward relative to the explosion-proof valve 40, ensuring sufficient gas discharge space between the under-plastic structure 10 and the explosion-proof valve 40. The provision of the vent holes 131 in the middle protrusion 130 not only serves to discharge gas, but also filters the rupture disk of the explosion-proof valve 40 in the event of explosion, preventing the rupture disk of the explosion-proof valve 40 from falling into the cell structure at the bottom of the under-plastic structure 10.

Specifically, the explosion-proof valve 40 can be attached to the under-plastic structure 10 by fastening, gluing, screwing, or other methods. In this embodiment, a locking groove 132 is provided on each side of the intermediate protrusion 130, where it connects to the first plate body 110 and the second plate body 120, and the explosion-proof valve 40 is locked into the locking groove 132. This allows the explosion-proof valve 40 to be attached to the backside of the intermediate protrusion 130 with a simple structure, simplifying the installation structure between the explosion-proof valve 40 and the intermediate protrusion 130. Furthermore, the recess depth of the locking groove 132 is smaller than the protruding height of the intermediate protrusion 130, providing a gap between the under-plastic structure 10 and the explosion-proof valve 40 and ensuring sufficient gas exhaust space. The recess depth of the locking groove 132 is equal to the thickness of the explosion-proof valve 40, ensuring that the top of the under-plastic structure 10 is tightly attached to the bottom of the aluminum reflective sheet 20, eliminating any gaps between the under-plastic structure 10 and the aluminum reflective sheet 20 and ultimately making the cell top cover more compact.

More specifically, the locking groove 132 may be provided at a midpoint in the width direction Y of the under-plastic structure 10 of the intermediate protrusion 130, or at a position close to both sides in the width direction Y of the under-plastic structure 10 of the intermediate protrusion 130. Preferably, in this embodiment, the locking groove 132 is provided at a midpoint in the width direction Y of the under-plastic structure 10 of the intermediate protrusion 130.

The intermediate protrusion 130 is rectangular, and the ventilation hole 131 is rod-shaped and extends along the width direction Y of the under-plastic structure 10. The ventilation holes 131 are uniformly spaced apart from one another on the intermediate protrusion 130. For example, the number of ventilation holes 131 may be six, twelve, or the like, depending on the actual situation. This is not a limitation in this embodiment. The ventilation hole 131 is set large in the width direction Y of the under-plastic structure 10, ensuring a sufficient gas discharge area for the explosion-proof valve 40, allowing the intermediate protrusion 130 to perform better gas conduction. The ventilation hole 131 is set small in the length direction X of the under-plastic structure 10 compared to the rupture disk of the explosion-proof valve 40, preventing the rupture disk of the explosion-proof valve 40 from falling into the cell structure at the bottom of the under-plastic structure 10.

In the above embodiment, the electrolyte of the cell is injected into the interior of the cell through the first liquid injection through-hole 121. An openwork stopper portion 140 is provided on the bottom side of the first liquid injection through-hole 121, and after the electrolyte enters the first liquid injection through-hole 121, it is injected so that it disperses into the interior of the cell through the openwork area of the stopper portion 140. Therefore, the stopper portion 140 can change the flow direction of the electrolyte injected into the interior of the cell from the first liquid injection through-hole, and can divide the electrolyte into multiple bundles and inject them into the interior of the cell along different directions, greatly reducing the obstruction of the electrolyte caused by the inner wall of the cell, thereby increasing the liquid injection speed through the first liquid injection through-hole 121 and shortening the liquid injection time. At the same time, because the electrolyte is divided into multiple bundles, the strength of the electrolyte's corrosion into the cell's interior is reduced while the electrolyte is being injected into the cell. This reduces the impact force of the electrolyte on the materials inside the cell, and the strength of the electrolyte's corrosion of the pole pieces inside the cell is also reduced, preventing the positive or negative electrode material in the pole pieces from peeling off due to electrolyte corrosion. Therefore, in this embodiment, damage to the pole pieces during liquid injection is prevented, and good conductivity of the pole pieces can be ensured.

By setting the area of the openwork region of the stopper portion 140 to be larger than the area of the cross section of the first liquid injection through-hole 121, it is ensured that the electrolyte injected through the first liquid injection through-hole 121 can flow out of the stopper portion 140 in a timely manner, preventing the stopper portion 140 from interfering with the electrolyte injected into the first liquid injection through-hole 121 and thereby preventing the stopper portion 140 from affecting the liquid injection speed.

Furthermore, after liquid injection is completed, the first liquid injection through-hole 121 must be sealed with the sealing nail 30. When negative pressure is created inside the cell, the stopper portion 140 acts to block the sealing nail 30, preventing the sealing nail 30 from being pushed into the cell by the negative pressure, causing sealing problems. This in turn prevents liquid leakage from the first liquid injection through-hole 121.

Therefore, this cell top cover under-plastic structure 10 can improve the liquid injection speed and prevent liquid leakage problems. Furthermore, by providing the intermediate protrusion 130, the overall strength of the under-plastic structure 10 can be increased.

7 is a diagram showing the combined configuration of a cell top cover provided in some embodiments of the present application; FIG. 8 is a perspective half-sectional view of an aluminum reflective sheet provided in some embodiments of the present application; FIG. 9 is a diagram showing the configuration of an explosion-proof valve provided in some embodiments of the present application; FIG. 10 is a diagram showing the configuration of another explosion-proof valve provided in some embodiments of the present application; FIG. 11 is a diagram showing the configuration of another explosion-proof valve provided in some embodiments of the present application; FIG. 12 is a diagram showing the configuration of another explosion-proof valve provided in some embodiments of the present application; FIG. 13 is a diagram showing the front view structure of another explosion-proof valve provided in some embodiments of the present application; and FIG. 14 is a diagram showing the configuration of another explosion-proof valve provided in some embodiments of the present application. 15 is a diagram showing the configuration of another explosion-proof valve provided in some embodiments of the present application; FIG. 16 is a diagram showing the front configuration of another explosion-proof valve provided in some embodiments of the present application; FIG. 17 is a diagram showing the assembled configuration of another cell top cover provided in some embodiments of the present application; FIG. 18 is a structural perspective view of the protective sheet provided in some embodiments of the present application; FIG. 19 is a structural perspective view of the gasket provided in some embodiments of the present application; FIG. 20 is a diagram showing the configuration of the protective sheet body provided in some embodiments of the present application; FIG. 21 is an exploded view provided in some embodiments of the present application; and FIG. 22 is an assembled structural view of the cell top cover and cell housing provided in some embodiments of the present application.

Note that the specific descriptions regarding the aluminum reflective sheet and under-plastic structure in the embodiments of Figures 1 to 6 also apply to the following embodiments. To avoid repetition, the under-plastic structure will not be described in detail in the following embodiments; for details, please refer to the corresponding descriptions above.

As shown in Figures 7 and 8, the cell top cover 300 provided in this embodiment includes an aluminum reflective sheet 301 and an explosion-proof valve 302. The aluminum reflective sheet 301 has a positive electrode column through-hole 303, a negative electrode column through-hole 304, and an explosion-proof through-hole 305 that penetrate the thickness of the aluminum reflective sheet 301, and the positive electrode column through-hole 303 and the negative electrode column through-hole 304 are respectively positioned in two different directions from the explosion-proof through-hole 305. The explosion-proof valve 302 is fixed to the aluminum reflective sheet 301 and covers the explosion-proof through-hole 305.

In the examples of the present application, the positional relationship between the positive electrode column through hole 303 and the negative electrode column through hole 304 is not limited, and when one of the positive electrode column through hole 303 and the negative electrode column through hole 304 shown in Figure 7 is a positive electrode column through hole, the other is a negative electrode column through hole.

The aluminum reflective sheet 301 is the main body of the cell top cover and is used to seal the cell, preventing electrolyte leakage and creating a closed chemical reaction space within the cell to facilitate electrochemical reactions. The positive electrode post through-hole 303 is used to insert the positive electrode post, connecting the positive electrode post to the external power consumption environment of the battery. The negative electrode post through-hole 304 is used to insert the negative electrode post, connecting the negative electrode post to the internal power consumption environment of the cell. The explosion-proof through-hole 305 is used to secure the explosion-proof valve 302, allowing gas to escape from the cell after the explosion-proof valve 302 is opened. The positive electrode post through-hole 303 and the negative electrode post through-hole 304 are located in two different directions from the explosion-proof through-hole 305, respectively, to prevent confusion between the positive electrode post and the negative electrode post.

In some embodiments, the aluminum reflective sheet 301 may be provided with a liquid injection hole 306 that penetrates the thickness of the aluminum reflective sheet 301. The liquid injection hole 306 is used to inject an electrolyte into the cell, causing an electrochemical reaction to occur in the electrolyte and generate an electric current. Figure 8 is a perspective half-sectional view of an aluminum reflective sheet provided in one embodiment of the present application, in which the aluminum reflective sheet 301 has a positive electrode column through-hole 303, a negative electrode column through-hole 304, an explosion-proof through-hole 305, and a liquid injection hole 306 that penetrate the thickness of the aluminum reflective sheet 301.

In some embodiments, the liquid injection hole 306 may be located away from the negative electrode post through-hole 304 and the corresponding negative electrode post. This prevents the electrolyte from accidentally leaking out when injecting the electrolyte into the liquid injection hole 306 and coming into contact with the negative electrode post, causing a current leak, which at least contributes to improving the safety of the battery.

As shown in Figures 7 and 9, the explosion-proof valve 302 is fixed to the aluminum reflective sheet 301 and covers the explosion-proof through-hole 305. The explosion-proof valve 302 has opposing upper and lower surfaces 31 and 32, with the upper surface 31 of the explosion-proof valve 302 facing the explosion-proof through-hole 305. When the cell is in normal use, the explosion-proof valve 302 serves to seal the cell and prevent leakage of the electrolyte inside the cell. When the air pressure inside the cell exceeds the explosion threshold of the explosion-proof valve 302, the explosion-proof valve 302 opens toward the outside of the cell, allowing the gas inside the cell to be discharged.

In some embodiments, the explosion-proof valve 302 may be made of aluminum or an aluminum alloy. For example, the explosion-proof valve 302 may be made of 1060 aluminum. The purity of 1060 aluminum is as high as 99.6% or more, providing excellent formability and resistance to various press, stretch, and bending processes, making it convenient for industrial production of explosion-proof valves with specific shapes. The 1060 aluminum has excellent corrosion resistance, which helps prevent corrosion of the explosion-proof valve 302 by the electrolyte in the battery, which would otherwise reduce the strength of the explosion-proof valve 302. Alternatively, the explosion-proof valve 302 may be made of a 3000-series aluminum alloy, such as a 3003 aluminum alloy, a 3105 aluminum alloy, or a 3A21 aluminum alloy. The 3000-series aluminum alloy is an aluminum-manganese alloy, and its high manganese content effectively enhances the corrosion resistance of the aluminum alloy, preventing corrosion of the explosion-proof valve 302 by the electrolyte and reducing the strength of the explosion-proof valve 302. The addition of manganese improves the welding performance of the aluminum alloy, making it easier to weld the explosion-proof valve 302 to the battery structure, preventing the welded portion of the explosion-proof valve 302 from rupturing due to pressure shock when pressure is released, and contributing to maintaining the integrity of the battery structure.

In some embodiments, the explosion-proof valve 302 may be formed by an extrusion process. Extrusion is a plastic processing method in which pressure is applied to a metal blank placed in a die cavity, causing directional plastic deformation in the metal blank, which is then forced out through a die hole in an extrusion die to obtain a part or semi-finished product with a desired cross-sectional shape and dimensions and consistent mechanical properties. Due to the process characteristics of extrusion, it can be used not only to produce rod, pipe, or wire products with simple cross-sectional shapes, but also to manufacture structures with complex cross-sectional shapes, making it useful for mass production of complex-shaped explosion-proof valve structures. In addition, extrusion-molded products have high precision, good product surface quality, and good compatibility with light metals such as aluminum or light alloys such as aluminum alloys, which can reduce product reject rates and effectively increase material utilization and yield.

In some embodiments, the explosion-proof valve 302 may be capsule-shaped. A capsule-shaped valve has a rectangular central section, with two opposing sides extending in an arcuate shape, forming a capsule-like shape. The straight sides of the arcuate section overlap with the straight sides of the rectangle. The symmetrical structure helps to uniformly distribute the force on the explosion-proof valve 302, concentrating stress on the explosion-proof valve 302 in a certain area and preventing the explosion-proof valve 302 from accidentally opening, ensuring normal operation of the explosion-proof valve 302. The arcuate design also reduces the sharp corners of the explosion-proof valve 302, contributing to processing and manufacturing. For example, in extrusion molding, the material of a rounded workpiece flows more smoothly through the mold than a workpiece with sharp corners, and stress at the corners of the workpiece is also reduced, improving the quality of the explosion-proof valve 302.

As shown in FIG. 9 , the explosion-proof valve 302 includes an explosion notch 307 and a reinforcing rib 308. The explosion notch 307 is a recess extending from the upper surface 31 toward the lower surface 32. The explosion notch 307 is a weak portion on the explosion-proof valve 302 that is used to burst when the air pressure inside the cell exceeds the explosion threshold of the explosion-proof valve 302, forming an opening in the explosion-proof valve 302 for venting gas, thereby equalizing the air pressure inside and outside the cell and preventing the battery from exploding. The reinforcing rib 308 is located within a portion of the recess and is used to prevent the explosion notch 307 from completely tearing and to control the direction of the released gas. The distance between the reinforcing rib 308 and the negative electrode pillar through hole 304 (see FIG. 7) is smaller than the distance between the reinforcing rib 308 and the positive electrode pillar through hole 303 (see FIG. 7), which prevents the ejected gas from ejecting toward the negative electrode pillar through hole 304 and the negative electrode pillar corresponding to the negative electrode pillar through hole 304, and prevents contact between the small amount of electrolyte carried by the ejected gas and the negative electrode pillar, thereby preventing leakage of electricity from the negative electrode pillar and at least contributing to improved safety performance of the battery.

In some embodiments, the thickness of the explosion notch 307 ranges from 0.1 mm to 0.15 mm, and may be, for example, 0.01 mm, 0.02 mm, 0.12 mm, or 0.15 mm. Controlling the thickness of the explosion notch 307 allows the explosion threshold of the explosion notch 307 to be controlled. This allows the explosion notch 307 to be set to release at an appropriate pressure, avoiding any impact on the normal use of the battery. For example, the explosion notch 307 can be prevented from suddenly opening during normal use of the battery, thereby preventing electrolyte leakage. It can also be prevented, for example, from the explosion notch 307 not opening even when the battery explosion pressure is reached, thereby preventing the explosion-proof valve 302 from losing its explosion-proof function.

In some embodiments, the cross-sectional shape of the depression may be an inverted trapezoid with a height of 0.18 mm, a long side length of 0.3 mm, and a short side length of 0.2 mm. As can be appreciated, when designing the explosive indentations 307, properties such as different cross-sectional shapes, deployment lengths, depression depths, and depression widths can be varied to suit different usage scenarios depending on the set explosion threshold.

In some embodiments, the thickness of the reinforcing ribs 308 is greater than the thickness of the explosion indentations 307. The reinforcing ribs 308 are located within a portion of the recess and are used to strengthen the connection between the explosion indentations 307 and the external platform and connecting parts, preventing the explosion indentations 307 from being completely torn off when the explosion-proof valve 302 is opened, preventing the rupture disk from separating, and preventing the rupture disk from impacting other structures inside the battery after separation, thereby contributing to improved battery safety.

In some embodiments, the thickness of the reinforcing rib 308 ranges from 0.16 mm to 0.25 mm, and may be, for example, 0.16 mm, 0.18 mm, 0.21 mm, or 0.25 mm. As can be appreciated, the thickness of the reinforcing rib 308 can be freely designed, as long as the reinforcing rib 308 can serve to strengthen the connection between the explosive notches 307 and the external platform and connection portion.

In some embodiments, the deployed length of the reinforcing rib 308 may be 1/6 or less of the deployed length of the explosion notches 307. This avoids the problem of the tearable portion of the explosion notches 307 being too short, which affects the gas discharge ability of the explosion-proof valve 302, and at least improves the explosion-proof effect of the explosion-proof valve 302. This improves the safety of the battery. As can be understood, the proportion of the deployed length of the reinforcing rib 308 to the deployed length of the explosion notches 307 needs to be set in accordance with the structure of the explosion notches 307.

In some embodiments, the explosion-proof valve 302 of the cell top cover may include an installation indicator mark. The installation indicator mark may be located on the underside. The installation indicator mark may also be located adjacent to the reinforcing rib 308. The purpose of providing the installation indicator mark is to improve the visibility of the installation direction of the explosion-proof valve 302. This standardizes the installation direction of the explosion-proof valve 302, guides the direction of the airflow inside the cell after the explosion-proof valve 302 is opened, and prevents the airflow from damaging the internal structure of the battery, thereby helping to improve battery safety.

In some embodiments, the shape of the attachment mark may be a letter. In some embodiments, the shape of the attachment mark may be a pattern. As can be appreciated, the shape of the attachment mark may be any shape as long as the attachment mark is visible.

As shown in FIG. 10 , in some embodiments, the explosion-proof valve 302 further includes a connecting portion 309. The connecting portion 309 includes a first outer ring portion 319 and a second outer ring portion 329. The first outer ring portion 319 is disposed around the outer periphery of the explosion notches 307, and the first outer ring portion 319 is connected to the explosion notches 307. The second outer ring portion 329 is disposed around the outer periphery of the first outer ring portion 319, and the second outer ring portion 329 is connected to the first outer ring portion 319. Here, the thickness of the first outer ring portion 319 is less than or equal to the thickness of the second outer ring portion 329.

The function of the connection 309 is to facilitate the connection between the explosion-proof valve 302 and the cell top cover. In some embodiments, the connection 309 and the cell top cover can be welded together to secure the explosion-proof valve 302 and the cell top cover, thereby sealing the cell and preventing leakage of the electrolyte inside the cell.

The second outer ring portion 329 is used to provide a contact surface and contributes to the connection between the explosion-proof valve 302 and the cell top cover. This defines a specific area to facilitate connection between the explosion-proof valve 302 and the cell top cover, increases the degree of standardization of the explosion-proof valve 302, helps improve assembly efficiency, improves production efficiency, and avoids quality issues caused by imperfect alignment during assembly of the explosion-proof valve 302 and the cell top cover, contributing to improved battery safety.

To facilitate the processing of the explosion indentations 307, the thickness of the first outer ring portion 319 may be smaller than the thickness of the second outer ring portion 329, and the thickness of the first outer ring portion 319 may be greater than the thickness of the explosion indentations 307. For example, when processing the explosion-proof valve 302 using an extrusion molding process, it is usually not possible to form explosion indentations with precise dimensions, and it is necessary to perform secondary processing on the explosion-proof valve 302 after extrusion molding to etch the explosion indentations 307 with precise dimensions into the explosion-proof valve 302. To simplify the etching process, the thickness of the first outer ring portion 319 may be smaller than the thickness of the second outer ring portion 329.

In some embodiments, the thickness of the second outer ring portion 329 ranges from 0.3 mm to 0.7 mm, and may be, for example, 0.3 mm, 0.4 mm, 0.5 mm, or 0.7 mm. In some embodiments, the thickness of the second outer ring portion 329 is the same as the thickness of the substrate forming the explosion-proof valve 302. Because the second outer ring portion 329 connects the explosion-proof valve 302 to the cell top cover, the second outer ring portion 329 must have a certain thickness to avoid problems with the explosion-proof valve 302 and the cell top cover falling off due to the second outer ring portion 329 being too thin, which would affect the safety of the battery. At the same time, the second outer ring portion 329 must not be too thick, which prevents it from occupying more space than necessary for other structures in the cell top cover and contributes to avoiding material waste.

As shown in FIG. 10 , in some embodiments, the explosion-proof valve 302 may further include a rupture disk 310, which is connected to the inner periphery of the explosion grooves 307 and which is attached to the outer periphery of the rupture disk 310. During normal use of the battery, the rupture disk 310 is connected to the explosion grooves 307, creating a sealed space inside the cell and making it easier to maintain a stable electrochemical reaction environment. When the air pressure inside the cell exceeds the explosion threshold of the explosion-proof valve 302, the explosion grooves 307 are torn, disconnecting the rupture disk 310 from the explosion grooves 307. The rupture disk 310 is then released to the outside of the cell by the impact of the gas inside the cell, guiding the airflow and preventing the small amount of electrolyte contained in the airflow from scattering in all directions, thereby preventing corrosion of the battery structure.

In some embodiments, the reinforcing rib 308 and the rupture disk 310 may be formed as a single unit. This strengthens the connection between the reinforcing rib 308 and the rupture disk 310, preventing the reinforcing rib 308 and the rupture disk 310 from separating and failing to direct the direction of the ejected airflow when the explosion-proof valve 302 is opened, thereby at least helping to improve the safety of the battery.

In some embodiments, the rupture disk 310 may be a planar structure with a uniform thickness. The rupture disk 310 may be provided with X-shaped or Y-shaped blast reinforcement ribs 308, which can prevent the rupture disk from being deformed by the air pressure inside the cell, prevent the blast notches 307 from being subjected to stress from the rupture disk 310, which can reduce the strength, prevent a reduction in the blast threshold, and at least improve the safety performance of the battery.

In some embodiments, as shown in FIG. 11, the rupture disk 310 may further include an internal platform 311 and an external platform 312 arranged around the outer periphery of the internal platform 311, where the external platform 312 is connected to the internal platform 311 and the thickness of the internal platform 311 is greater than the thickness of the external platform 312. This increases the strength of the rupture disk 310, prevents deformation of the rupture disk 310, reduces stress from the rupture disk 310 subjected to the explosive notches 307, contributes to preventing changes in the explosion threshold of the explosive notches 307, and improves the safety of the battery.

In some embodiments, the thickness of the external platform 312 is greater than the thickness of the explosion increment 307. This allows the opening point of the explosion-proof valve 302 to be precisely controlled to the explosion increment 307, avoiding the problem of the explosion-proof valve 302 opening at an inconsistent point, helping to control the direction of the gas released after the explosion-proof valve 302 is opened, preventing corrosion of the battery structure by the small amount of electrolyte contained in the released gas, and helping to improve the safety of the battery.

In some embodiments, the thickness of the internal platform 311 may be equal to or less than the thickness of the connecting portion 309. In other embodiments, the thickness of the internal platform 311 may be greater than the thickness of the connecting portion 309. The thickness of the internal platform 311 is affected by the manufacturing process of the explosion-proof valve 302. For example, when the explosion-proof valve 302 is manufactured using an extrusion molding method, the material has good plastic deformation ability, so some of the material in the explosion-proof valve 302 can be pressed against the internal platform 311, making the thickness of the internal platform 311 greater than the thickness of the connecting portion 309. This increases the thickness of the rupture disk 310, which at least increases the strength of the rupture disk 310, prevents the rupture disk 310 from easily deforming, and improves the safety of the battery.

In some embodiments, as shown in FIG. 12 , the rupture disk 310 may further include a first sloped portion 313. The first sloped portion 313 is connected between the outer platform 312 and the inner platform 311, and the thickness of the first sloped portion 313 gradually increases along the direction from the outer platform 312 to the inner platform 311 until it becomes the same thickness as the inner platform 311. The first sloped portion 313 forms a transition between the outer platform 312 and the inner platform 311, reducing the manufacturing difficulty of the explosion-proof valve 302. The first sloped portion 313 also reduces the structural stress on the edges and corners of the explosion-proof valve 302, helping to prevent excessive stress concentration on the edges and corners of the explosion-proof valve 302, which could lead to damage, thereby improving product quality.

13, the first inclined portion 313 includes a first inclined surface 33 and a bottom surface 34 facing the first inclined surface 33, the bottom surface 34 being part of the lower surface 32. The first inclined surface 33 connects the surface of the inner platform 311 with the surface of the outer platform 312, and the angle between the first inclined surface 33 and a normal to the bottom surface 34 ranges from 60° to 89°, and may be, for example, 60°, 75°, 85°, or 89°. As can be appreciated, as long as the first inclined portion 313 can connect the thickness of the outer platform 312 with the thickness of the inner platform 311, the angle between the first inclined surface 33 and the normal to the bottom surface 34 can be freely set according to the type of processing process for the explosion-proof valve.

In some embodiments, as shown in FIG. 14 , the explosion-proof valve 302 may further include an inner recess 314. The inner recess 314 is located in the central region of the rupture disk 310 and is recessed from the upper surface 31 to the lower surface 32 of the explosion-proof valve 302, with the inner platform 311 surrounding the outer periphery of the inner recess 314. The process of forming the inner recess 314 includes a press-molding process, and the formed explosion-proof valve 302 can be reprocessed using a press and a mold. While the process of forming the explosion-proof valve 302 inevitably results in an uneven surface on the explosion-proof valve 302, forming the inner recess 314 reduces the degree of unevenness on the surface of the explosion-proof valve 302, resulting in an explosion-proof valve 302 with better surface quality. This avoids quality issues caused by uneven stress on the surface of the explosion-proof valve 302 and helps improve battery safety.

In some embodiments, the thickness of the inner recess 314 may be greater than the thickness of the explosion notch 307. This prevents the explosion-proof valve 302 from opening at the inner recess 314 without opening at the explosion notch 307, or prevents the explosion-proof valve 302 from opening at both the inner recess 314 and the explosion notch 307 at the same time, which helps control the opening position of the explosion-proof valve 302 and controls the direction in which the airflow inside the battery escapes after the explosion-proof valve 302 opens, preventing the small amount of electrolyte carried by the airflow from corroding the battery structure.

In some embodiments, the thickness of the inner recess 314 may be less than or equal to the thickness of the connecting portion 309. In other embodiments, the thickness of the inner recess 314 may be greater than the thickness of the connecting portion 309. The thickness of the inner recess 314 can be freely set depending on the manufacturing process. However, as will be appreciated, regardless of the manufacturing process, the thickness of the inner recess 314 will be less than the thickness of the internal platform 311.

In some embodiments, as shown in FIG. 15, the rupture disk 310 may further include a second inclined portion 315. The second inclined portion 315 is connected between the inner platform 311 and the inner recess 314, and the thickness of the second inclined portion 315 gradually decreases along the direction from the inner platform 311 to the inner recess 314. The second inclined portion 315 forms a transition between the inner recess and the inner platform 311, reducing the manufacturing difficulty of the explosion-proof valve 302. The second inclined portion 315 also reduces the structural stress on the edges and corners of the explosion-proof valve 302, helping to prevent the edges and corners of the explosion-proof valve 302 from being damaged due to excessive stress concentration, thereby improving product quality.

16, the second inclined portion 315 includes a second inclined surface 35 and a second bottom surface 36 facing the second inclined surface 35, the second bottom surface 36 being part of the lower surface 32. The second inclined surface 35 connects the surface of the internal platform 311 to the surface of the internal recess 314, and the angle between the second inclined surface 35 and a normal line perpendicular to the second bottom surface 36 may be less than 30°, such as 30°, 28°, 15°, or 9°. As can be appreciated, as long as the second inclined portion can serve to connect the thickness of the internal platform 311 to the thickness of the internal recess 314, the angle between the second inclined surface 35 and a normal line perpendicular to the second bottom surface 36 can be freely set according to the processing steps of the explosion-proof valve 302.

In some embodiments, as shown in FIG. 17, the cell top cover 300 further includes a protective sheet 316. The protective sheet 316 is fixed to the aluminum reflective sheet 301 and covers the explosion-proof through-hole 305 (see FIG. 7). The protective sheet 316 is used to protect the explosion-proof valve 302 (see FIG. 7) and prevent the explosion-proof valve 302 from being damaged by foreign objects, preventing the explosion-proof valve from being damaged and unable to be used normally. This helps to avoid battery explosions and at least improve the safety of the battery. The protective sheet 316 is also used to block the small amount of electrolyte carried away by the airflow that escapes after the explosion-proof valve 302 is opened, preventing the electrolyte from splashing onto the negative electrode column due to the airflow that escapes, causing a cell short circuit.

In some embodiments, the protective sheet 316 may be made of a transparent or translucent material. This makes it easier to observe the condition of the top surface of the explosion-proof valve 302, contributing to timely detection of damage to the explosion-proof valve 302 and the taking of appropriate measures, avoiding safety issues that may arise from the use of the explosion-proof valve 302 if it is damaged, and helping to improve battery safety.

In some embodiments, as shown in Figures 18 to 20, the protective sheet 316 may be composed of a gasket 317 and a protective sheet main body 318. The protective sheet main body 318 is fixed to the gasket 317 and covers the explosion-proof through-hole 305 (see Figure 7), and the gasket 317 is fixed to the aluminum reflective sheet 301 and surrounds the outer periphery of the explosion-proof through-hole 305. This allows the protective sheet 316 and the aluminum reflective sheet 301 to be fixed in a specific area, which helps to increase the standardization of the cell top cover, improves assembly efficiency, and increases production efficiency. It also avoids quality issues caused by imperfect alignment during assembly of the protective sheet 316 and the cell top cover, contributing to improved battery safety. Figure 19 is a perspective structural diagram of the gasket provided in an embodiment of the present application, and Figure 20 is a diagram showing the configuration of the protective sheet main body provided in an embodiment of the present application.

In some embodiments, as shown in FIG. 18, the protective sheet 316 may have an opening 320 penetrating the thickness of the protective sheet 316. The function of the opening 320 is to form a gas flow path, preventing the gas inside the cell from being blocked and unable to be discharged after the explosion-proof valve is opened, and to prevent the cell from exploding due to an increase in internal pressure.

In some embodiments, the opening 320 is located in the edge region of the protective sheet away from the liquid inlet, so that any remaining electrolyte after injecting liquid into the liquid inlet can enter the cavity between the protective sheet 316 and the explosion-proof valve 302 through the opening 320, preventing the electrolyte from corroding the explosion-proof valve and damaging the explosion-proof valve 302, preventing it from being used normally.

In some embodiments, the distance from the end of the opening 320 to the center of the protective sheet 316 is smaller than the distance from the edge of the protective sheet to the center of the protective sheet 316. This controls the direction and range of the gas ejected from the opening 320, reduces damage to the battery structure caused by the ejected gas, and at least contributes to improving battery safety.

In some embodiments, the shape of the opening 320 may be circular. In other embodiments, the shape of the opening 320 may be square. In other embodiments, the shape of the opening 320 may be L-shaped. As can be appreciated, the function of the opening 320 is to allow gas communication between the cavity between the protective sheet 316 and the explosion-proof valve 302 and the external environment, and therefore the shape of the opening 320 may be of a variety of types.

In some embodiments, the openings 320 are located in the edge area of the protective sheet 316 away from the negative electrode post through-hole and the corresponding negative electrode post, which helps prevent electrolyte sprayed from the openings 320 from splashing onto the negative electrode post and causing a current leak in the negative electrode post, thereby avoiding sparks caused by a current leak and improving the safety of the battery.

In some embodiments, the width of opening 320 within protective sheet 316 in a direction perpendicular to the direction from opening 320 toward the center of protective sheet 316 is 1 mm or less. For example, if opening 320 is rectangular with its short side facing toward the center of protective sheet 316, the length of the short side of opening 320 within protective sheet 316 may be 0.1 mm, 0.2 mm, 0.5 mm, or 1 mm, for example. This prevents foreign matter from entering the cavity between protective sheet 316 and explosion-proof valve 302 due to the opening 320 being too wide, thereby preventing foreign matter from destroying or corroding the explosion-proof valve and preventing normal use of explosion-proof valve 302 and contributing to improved battery safety.

As shown in FIG. 21, in some embodiments, the cell top cover 300 may include structures such as a positive electrode upper plastic 321, a negative electrode upper plastic 322, a positive electrode sealing ring 323, a negative electrode sealing ring 324, an under-plastic structure 325, and a positive electrode pole 326 or a negative electrode pole 327.

Figure 22 is an assembly diagram of the cell top cover 300 and cell housing 400 provided in an embodiment of the present application, in which the cell top cover 300 is attached to the top of the cell housing 400.

The cell top cover 300 provided in the above embodiment includes an aluminum reflective sheet 301 and an explosion-proof valve 302. The aluminum reflective sheet 301 is the main body of the cell top cover 300 and is used to seal the cell. The aluminum reflective sheet 301 has a positive electrode post through-hole 303, a negative electrode post through-hole 304, and an explosion-proof through-hole 305 that penetrate the thickness of the aluminum reflective sheet 301. The positive electrode post through-hole 303 is used to drill a positive electrode post, contributing to the positive electrode post connecting the inside of the cell with the power consumption environment outside the battery. The negative electrode post through-hole 304 is used to drill a negative electrode post, contributing to the negative electrode post connecting the inside of the cell with the power consumption environment outside the battery. The explosion-proof through-hole 305 is used to fix the explosion-proof valve 302 and contributes to the release of gas inside the cell after the explosion-proof valve 302 is opened. The positive electrode post through-hole 303 and the negative electrode post through-hole 304 are located at two different orientations of the explosion-proof through-hole 305, respectively, to avoid confusion between the positive electrode post and the negative electrode post. The explosion-proof valve 302 is fixed to the aluminum reflective sheet 301 and covers the explosion-proof through-hole 305. The explosion-proof valve 302 has opposing upper and lower surfaces 31 and 32, with the upper surface 31 of the explosion-proof valve 302 facing the explosion-proof through-hole 305. The explosion-proof valve 302 seals the cell during normal use and prevents leakage of the electrolyte inside the cell. The explosion-proof valve 302 includes explosion notches 307 and reinforcing ribs 308. The explosion notches 307 are recesses recessed from the upper surface 31 toward the lower surface 32. The explosion notches 307 are weak parts in the explosion-proof valve 302 and rupture when the air pressure inside the cell exceeds the explosion threshold of the explosion-proof valve 302, forming an opening in the explosion-proof valve 302 for discharging gas, thereby equalizing the air pressure inside and outside the cell and preventing the battery from exploding. The reinforcing ribs 308 are located within a partial area of the recess and are used to prevent the explosion notches 307 from completely tearing and to control the direction of the released gas. The distance between the reinforcing rib 308 and the negative electrode column through hole 304 is smaller than the distance between the reinforcing rib 308 and the positive electrode column through hole 303, which prevents the emitted gas from spraying toward the negative electrode column through hole 304 and the negative electrode column corresponding to the negative electrode column through hole 304, and prevents contact between the small amount of electrolyte carried by the emitted gas and the negative electrode column, thereby preventing leakage of electricity from the negative electrode column and at least contributing to improved safety performance of the battery.

Note that in the embodiments shown in Figures 1 to 6 and the embodiments shown in Figures 7 to 22, different terms are used for similar components, for example, the fourth electrode post through hole 230 and the positive electrode post through hole 303, and the third electrode post through hole 220 and the negative electrode post through hole 304. However, their positions and functions are similar, and the details of each embodiment can be combined with each other as long as they are not inconsistent.

The above has provided a detailed description of the "cell top cover under-plastic structure and cell top cover" according to an embodiment of the present invention. While the present specification has used specific examples to explain the principles and embodiments of the present invention, the description of the above embodiments is intended only to aid in understanding the concept of the present invention, and specific embodiments and scope of application may be modified. In short, the contents of this specification should not be understood as limiting the present invention. Those skilled in the art will understand that the above embodiments are specific examples for realizing the present disclosure, but that various modifications in form and detail may be made in practice without departing from the spirit and scope of the present disclosure.

Claims (17)

The aluminum reflective sheet, the under-plastic structure, and the sealing nail are included.
the upper side of the under-plastic structure is disposed on the bottom side of the aluminum reflective sheet, wherein:
The under-plastic structure includes a first plate body, a second plate body, and an intermediate protrusion located between the first plate body and the second plate body, the intermediate protrusion protruding from a bottom side of the first plate body and a bottom side of the second plate body,
a first electrode post through hole is provided in the first plate body, a first liquid injection through hole and a second electrode post through hole are provided in the second plate body, and a stopper portion protruding from a circumferential side of the first liquid injection through hole is provided on a bottom side of the second plate body;
the stopper portion includes a side surface and a bottom surface, the side surface being continuous with the bottom side of the second plate body, surrounding the periphery of the first liquid injection through hole, extending in a direction away from the second plate body, and being continuous with the bottom surface;
a plurality of diversion holes are uniformly spaced apart along the circumferential direction of the side surface, and the total area of all the diversion holes is greater than the cross-sectional area of the first liquid injection through-hole;
a second liquid injection through hole having the same central axis as the first liquid injection through hole is provided in the aluminum reflective sheet, the sealing nail is inserted into the second liquid injection through hole, and a gap between a bottom end of the sealing nail and a bottom of the stopper portion is set to 0.5 mm to 2 mm;
the second liquid-injection through-hole is a stepped hole including a first hole segment and a second hole segment, the radial dimension of the first hole segment being larger than the radial dimension of the second hole segment, and the second hole segment being closer to the first liquid-injection through-hole;
A cell top cover characterized by: The first plate body and the second plate body are provided with side end protrusions on both sides spaced apart from each other, the side end protrusions protruding from the bottom side of the first plate body and the bottom side of the second plate body, and the side end protrusions are provided with a plurality of holes.
The cell top cover according to claim 1 . The side end protrusion has a frame structure, and a plurality of reinforcing ribs extending along the length of the under-plastic structure are provided within the side end protrusion.
3. The cell top cover according to claim 2 . The intermediate protrusion further includes an explosion-proof valve, the intermediate protrusion is provided with a plurality of ventilation holes, the explosion-proof valve is attached to the rear surface of the intermediate protrusion and is disposed opposite the plurality of ventilation holes.
The cell top cover according to any one of claims 1 to 3 . a locking groove is provided on each of the two sides of the intermediate protrusion connected to the first plate body and the second plate body, the explosion-proof valve is locked in the locking groove, and the recess depth of the locking groove is smaller than the protruding height of the intermediate protrusion;
5. The cell top cover according to claim 4 . The intermediate protrusion has a rectangular shape, the ventilation hole has a rod shape and extends along the width direction of the under-plastic structure, and the ventilation holes are uniformly spaced apart from one another on the intermediate protrusion.
5. The cell top cover according to claim 4 . the aluminum reflective sheet has a positive electrode post through-hole, a negative electrode post through-hole, and an explosion-proof through-hole that penetrate through the thickness of the aluminum reflective sheet, and the positive electrode post through-hole and the negative electrode post through-hole are respectively located in two different directions of the explosion-proof through-hole; and further comprises an explosion-proof valve, the explosion-proof valve having opposing upper and lower surfaces, the explosion-proof valve being fixed to the aluminum reflective sheet to cover the explosion-proof through-hole, the upper surface facing the explosion-proof through-hole, wherein the explosion-proof valve includes explosion serrations and a reinforcing rib, the explosion serrations being recesses recessed from the upper surface toward the lower surface, the reinforcing rib being located within a partial area of the recess, and the distance between the reinforcing rib and the negative electrode post through-hole is smaller than the distance between the reinforcing rib and the positive electrode post through-hole;
The cell top cover according to claim 1 . The thickness range of the explosion cut is 0.1 mm to 0.15 mm.
The cell top cover according to claim 7 . The thickness of the reinforcing rib is greater than the thickness of the explosion notch;
The cell top cover according to claim 7 . The thickness range of the reinforcing rib is 0.16 mm to 0.25 mm.
The cell top cover according to claim 9 . The developed length of the reinforcing rib is 1/6 or less of the developed length of the explosive notch.
The cell top cover according to claim 7 . The explosion-proof valve further includes an installation mark, the installation mark is located on the lower surface, and the installation mark is provided adjacent to the reinforcing rib.
The cell top cover according to claim 7 . The explosion-proof valve further includes a connecting portion, the connecting portion including a first outer ring portion and a second outer ring portion;
The first outer ring portion is disposed around the outer periphery of the explosive notches, and the first outer ring portion is connected to the explosive notches;
the second outer ring portion is provided around an outer periphery of the first outer ring portion, and the second outer ring portion is connected to the first outer ring portion;
Here, the thickness of the first outer ring portion is equal to or less than the thickness of the second outer ring portion.
The cell top cover according to claim 7 . The thickness range of the second outer ring portion is 0.3 mm to 0.7 mm.
14. The cell top cover according to claim 13 . The explosion-proof valve further includes a rupture disk, wherein the rupture disk is connected to the inner periphery of the explosion notch, and the explosion notch is disposed around the outer periphery of the rupture disk;
14. The cell top cover according to claim 13 . The reinforcing rib and the rupture disk are integrally molded.
16. The cell top cover of claim 15 . A cell top cover according to claim 1 and a cell housing, wherein the cell top cover is attached to an upper portion of the cell housing.
A cell characterized by: