Cover plate assembly and battery

Abstract

The application relates to the technical field of lithium batteries, and provides a cover plate assembly and a battery. The cover plate assembly comprises a cover plate body and a lower plastic part; the lower plastic part is respectively provided with a first groove and a second groove at both ends in the length direction, the bottom of the first groove and the bottom of the second groove are used for limiting the electric core in the battery shell; the first groove is correspondingly arranged with a liquid injection hole on the cover plate body, the bottom wall of the first groove is in a stepped shape, and the bottom wall is provided with a first flat wall and a second flat wall which are arranged at intervals along the liquid injection direction, and a vertical wall which connects the first flat wall and the second flat wall, the second flat wall has a closed area opposite to the liquid injection hole and a flow-through area except the closed area, and the flow-through area, the vertical wall and the first flat wall are all provided with liquid passing holes. The cover plate assembly can not only avoid damage of electrolyte injection pressure to the pole group during liquid injection, but also ensure the smooth performance of the battery vacuum pumping operation and the operation efficiency of the vacuum pumping.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a cover plate assembly. This application also relates to a battery equipped with the aforementioned cover plate assembly. Background Technology

[0002] A typical lithium battery structure includes a casing, electrode arrays and electrolyte housed within the casing, and a cover assembly sealing the casing. The cover assembly typically consists of a cover body and a casing, usually fixed together by laser welding, forming a sealed space that protects the electrode arrays and provides structural strength. The cover assembly includes a cover body, a lower plastic component, and an explosion-proof valve. The cover body has an injection hole, and the lower plastic component has a through-hole communicating with the injection hole, allowing electrolyte to flow into the casing and wet the electrode arrays.

[0003] In traditional structures, to accelerate the flow of electrolyte into the housing, the through holes on the lower plastic part and the injection holes on the cover plate body are concentrically set, and the cross-sectional area of ​​the through holes is larger than that of the injection holes, so that there is no obstruction when the electrolyte enters the through holes from the injection holes, thereby increasing the injection speed.

[0004] However, due to the relatively fragile structure of the electrode assembly, it is often damaged during electrolyte injection. Furthermore, after electrolyte injection, the battery interior typically requires vacuuming before the sealing plug and cap are installed to seal the casing. During vacuuming, the tabs on the electrode assembly are affected by the negative pressure inside the battery, which can cause them to block the through-holes in the lower plastic component, affecting vacuuming efficiency. Utility Model Content

[0005] In view of this, this application aims to provide a cover plate assembly that can prevent damage to the electrode assembly by the electrolyte injection pressure during liquid injection, while ensuring the efficiency of vacuuming operations.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: A cover plate assembly includes a cover plate body and a lower plastic part disposed on one side of the cover plate body; The lower plastic part has a first groove and a second groove at both ends along its length, and the bottom of the first groove and the bottom of the second groove are used to limit the electrode assembly inside the battery casing. The first groove is provided corresponding to the injection hole on the cover plate body, and the bottom wall of the first groove is stepped, and has a first flat wall and a second flat wall spaced apart along the injection direction, as well as a vertical wall connecting the first flat wall and the second flat wall. The second flat wall has a closed area opposite to the injection hole, and a flow area other than the closed area. The flow area, the vertical wall and the first flat wall are all provided with liquid passage holes.

[0007] Furthermore, in the thickness direction of the lower plastic part, the distance L between the first straight wall and the second straight wall is between 0.5mm and 5mm.

[0008] Furthermore, a through hole is provided on the bottom wall of the second groove.

[0009] Furthermore, the liquid passage holes are a plurality of holes arranged at intervals; and / or, the liquid passage holes are round holes, elongated holes, or rectangular holes.

[0010] Furthermore, the lower plastic part is provided with an electrode mounting portion; the electrode mounting portion is located between the first groove and the second groove, and is disposed close to the second groove.

[0011] Furthermore, on the side of the lower plastic part away from the cover plate, a first cavity and a second cavity are formed on the lower plastic part, and the first cavity and the second cavity are respectively disposed on both sides of the pole mounting part; the first cavity and / or the second cavity are provided with reinforcing ribs.

[0012] Furthermore, it also includes a sealing plug and a sealing cap disposed at the injection hole; the injection hole is a stepped hole and has a first hole, a second hole and a third hole that communicate along the injection direction, a first step surface is formed between the first hole and the second hole, and a second step surface is formed between the second hole and the third hole; the sealing plug is interference-fitted into the third hole, and one end of the sealing plug is limited on the second step surface; the sealing cap is disposed in the first hole and is welded to the cover plate body.

[0013] Furthermore, the sealing plug has a limiting flange at one end near the sealing cover, which can abut against the second step surface; the sealing cover has a limiting protrusion on the side facing the sealing plug, which can restrict the movement of the sealing plug in the direction pointing outward from the cover plate body.

[0014] Furthermore, the limiting protrusion is provided with a limiting groove, and the limiting protrusion can be inserted into the limiting groove.

[0015] Compared with related technologies, this application has the following advantages: (1) The cover plate assembly described in this application, by providing a first groove and a second groove at both ends of the lower plastic part, and using the bottom of the first groove and the second groove to limit the electrode assembly inside the battery, not only facilitates the lightweight design of the lower plastic part, but also effectively limits the electrode assembly and prevents the electrode assembly from shaking inside the battery. Furthermore, the first groove is arranged to correspond with the injection hole, and the bottom wall of the first groove is stepped, having a first flat wall, a vertical wall and a second flat wall connected together. A closed area is provided on the second flat wall so that when the electrolyte is injected, the electrolyte first flows into the closed area, then flows to the flow area and flows into the housing through the flow area, the vertical wall and the through hole on the first flat wall. This can buffer the electrolyte and effectively avoid damage to the electrode assembly caused by the electrolyte injection pressure.

[0016] Moreover, the use of a vertical wall structure allows for a larger design of the electrode tab portion in the length direction of the lower plastic part compared to an inclined wall. At the same time, the liquid passage holes on the vertical wall and the first flat wall are spaced apart from the electrode tabs, so that they will not be blocked by the electrode tabs during the battery vacuuming process, thus ensuring the smooth progress and efficiency of the vacuuming operation.

[0017] (2) The restriction on the distance between the first flat wall and the second flat wall can effectively ensure that the first flat wall and the electrode group maintain a certain distance, so that the electrolyte can pass smoothly through the liquid passage hole on the vertical wall and the first flat wall, thereby improving the electrolyte injection efficiency. At the same time, the first groove part corresponding to the first flat wall can also further buffer the electrolyte during the injection process.

[0018] (3) A through hole is provided on the bottom wall of the second groove so that the injected electrolyte can enter the second groove through the through hole. This can, to a certain extent, play the role of storing electrolyte and can also increase the amount of electrolyte injected, which is beneficial to improving the service life of the battery.

[0019] (4) Multiple liquid passage holes can be set to further improve the electrolyte injection efficiency. The liquid passage holes are round holes, elongated holes or rectangular holes, which have a relatively simple structure and are easy to prepare and mold on the lower plastic part.

[0020] (5) An electrode mounting part is provided on the lower plastic part, so that the electrode mounting part is located close to the second groove. This allows the electrode mounted on the electrode mounting part to be far away from the position of the liquid injection hole, thereby avoiding the electrolyte overflow and contamination of the cover plate body surface and electrode during liquid injection.

[0021] (6) The first cavity and the second cavity provided on the lower plastic part are conducive to reducing the weight of the lower plastic part, and the reinforcing ribs provided can improve the overall structural strength of the lower plastic part.

[0022] (7) The sealing plug is set to be interference fit in the third hole of the injection hole, and one end of the sealing plug is limited to the second step surface, which can effectively improve the sealing performance at the injection hole. At the same time, it can better improve the sealing performance at the injection hole by cooperating with the welding connection between the sealing cap and the cover plate body.

[0023] (8) The limiting protrusion provided at one end of the sealing plug can increase the contact area with the nailing equipment, which is conducive to ensuring the assembly quality of the sealing plug when it is installed in the third hole. Furthermore, by using the limiting protrusion provided on the sealing cover, the limiting protrusion and the second step surface can effectively limit the axial displacement of the sealing plug, thereby ensuring that the sealing plug is always in the best sealing position.

[0024] (9) A limiting groove is provided on the limiting protrusion, that is, a limiting groove corresponding to the limiting protrusion is provided on the end face of the sealing plug, so that the limiting protrusion can be inserted into the limiting groove. In this way, by using the cooperation between the limiting protrusion and the limiting groove, when the gas pressure inside the cell pushes the plug, the sealing plug can be effectively prevented from moving in the opposite direction to the liquid injection direction, and the position reliability and sealing performance of the sealing plug can be further guaranteed.

[0025] Another object of this application is to provide a battery having a cover assembly as described above.

[0026] The battery described in this application, by employing the aforementioned cover plate assembly, not only avoids damage to the electrode assembly caused by the electrolyte injection pressure during electrolyte injection, but also ensures the smooth progress and efficiency of the battery vacuuming operation, thereby improving the battery's production efficiency and manufacturing quality. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a first-view structural schematic diagram of the cover plate assembly described in an embodiment of this application; Figure 2 This is a second-view structural schematic diagram of the cover plate assembly described in an embodiment of this application; Figure 3 This is a third-view structural schematic diagram of the cover plate assembly described in an embodiment of this application; Figure 4 for Figure 3 Sectional view from the AA direction; Figure 5 This is a first-view structural schematic diagram of the lower plastic part described in an embodiment of this application; Figure 6 This is a structural schematic diagram of the lower plastic part from a second perspective, as described in an embodiment of this application. Figure 7 This is a schematic diagram of the sealing state of the injection hole as described in the embodiments of this application; Figure 8 This is a schematic diagram of the injection hole structure described in an embodiment of this application; Figure 9 This is a schematic diagram of the sealing plug described in an embodiment of this application; Figure 10 This is a schematic diagram of the sealing cap structure described in an embodiment of this application; Explanation of reference numerals in the attached figures: 1. Cover plate body; 2. Lower plastic part; 3. Terminal post; 4. Battery casing; 5. Sealing plug; 6. Sealing cover; 101. Injection hole; 10. First hole; 20. Second hole; 30. Third hole; 21. First groove; 21a. First straight wall; 21b. Vertical wall; 21c. Second straight wall; 211. First liquid passage hole; 212. Second liquid passage hole; 213. Third liquid passage hole; 22. Second groove; 220. Through hole; 23. Pole post mounting part; 24. First cavity; 25. Second cavity; 231. First reinforcing rib; 232. Second reinforcing rib; 51. Main body; 52. Limiting protrusion; 520. Limiting groove; 61. Cover body; 62. Connecting edge; 611. Limiting protrusion. Detailed Implementation

[0028] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0030] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0032] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0034] An embodiment of the first aspect of this application provides a cover plate assembly that can prevent damage to the electrode assembly from electrolyte injection pressure during the injection process, while also ensuring the efficiency of vacuuming operations.

[0035] In related technologies, during the manufacturing process of lithium batteries, such as blade batteries, the amount of electrolyte injected is generally large, and the battery usually requires multiple electrolyte injections. In traditional structures, in order to accelerate the flow of electrolyte into the casing, the through holes on the lower plastic part and the injection holes on the cover plate body are concentrically arranged, and the cross-sectional area of ​​the through holes is larger than that of the injection holes. This ensures that there is no obstruction when the electrolyte enters the through holes from the injection holes, thereby increasing the injection speed.

[0036] However, due to the relatively fragile structure of the electrode assembly, it is often damaged during electrolyte injection. Furthermore, after electrolyte injection, the battery interior typically requires vacuuming before the sealing plug and cap are installed to seal the casing. During vacuuming, the tabs on the electrode assembly are affected by the negative pressure inside the battery, which can cause them to block the through-holes in the lower plastic component, affecting vacuuming efficiency.

[0037] In view of this, in order to overcome the shortcomings of the related technology, the cover plate assembly of this embodiment combines... Figures 1 to 10 As shown, the overall design includes a cover plate body 1 and a lower plastic part 2 located on one side of the cover plate body 1.

[0038] The lower plastic part 2 has a first groove 21 and a second groove 22 at both ends along its length. The bottom of the first groove 21 and the bottom of the second groove 22 are used to limit the electrode assembly inside the battery casing 4. The first groove 21 is corresponding to the injection hole 101 on the cover plate body 1, and the bottom wall of the first groove 21 is stepped. It has a first straight wall 21a and a second straight wall 21c spaced apart along the injection direction, and a vertical wall 21b connecting the first straight wall 21a and the second straight wall 21c. The second straight wall 21c has a closed area opposite to the injection hole 101 and a flow area other than the closed area. Liquid passage holes are provided on the flow area, the vertical wall 21b and the first straight wall 21a.

[0039] At this time, in the above structure, by setting the first groove 21 and the second groove 22 at both ends of the lower plastic part 2 respectively, and using the bottom of the first groove 21 and the second groove 22 to limit the electrode group inside the battery, it is not only beneficial to the lightweight design of the lower plastic part 2, but also to better limit the electrode group and prevent the electrode group from shaking inside the battery.

[0040] Furthermore, the first groove 21 is arranged to correspond with the injection hole 101. The bottom wall of the first groove 21 is stepped, and it has a first flat wall 21a, a vertical wall 21b and a second flat wall 21c connected together. A closed area is provided on the second flat wall 21c so that when the electrolyte is injected, the electrolyte first flows into the closed area, then flows into the flow area and flows into the housing through the flow area, the vertical wall 21b and the through hole on the first flat wall 21a. This can buffer the electrolyte and effectively avoid damage to the electrode assembly caused by the electrolyte injection pressure.

[0041] Moreover, the vertical wall 21b structure allows for a larger electrode tab size in the length direction of the lower plastic part 2 compared to the inclined wall. At the same time, the liquid passage holes on the vertical wall 21b and the first flat wall 21a are spaced apart from the electrode tabs, so that they will not be blocked by the electrode tabs during the battery vacuuming process, thus ensuring the smooth progress and efficiency of the vacuuming operation.

[0042] Based on the above overview, specifically, let's continue to combine... Figures 1 to 10 As shown, the cover assembly includes a cover body 1 and a lower plastic part 2. The cover body 1 is used to weld and connect with the battery casing 4 to form a sealed cavity structure for accommodating the electrode assembly and electrolyte. The lower plastic part 2 is located on one side of the cover body 1 and sandwiched between the cover body 1 and the battery casing 4. The lower plastic part 2 can protect the cell structure, provide electrical insulation, and buffer and shock absorption.

[0043] In this embodiment, the lower plastic part 2, in terms of its specific structure, refers to... Figures 1 to 6As shown, the lower plastic part 2 has a first groove 21 and a second groove 22, which are located at both ends along the length of the lower plastic part 2. The bottom of the first groove 21 and the bottom of the second groove 22 are used to limit the electrode assembly inside the battery casing 4. In specific implementation, the bottom of the first groove 21 and the bottom of the second groove 22 abut against the separator of the electrode assembly, avoiding compression of the electrode sheets while enabling better positioning of the electrode assembly.

[0044] The bottom wall of the first groove 21 is stepped and has a first flat wall 21a, a vertical wall 21b, and a second flat wall 21c connected in sequence. The first flat wall 21a is positioned closer to the cover plate body 1 than the second flat wall 21c. The portion of the second flat wall 21c opposite to the injection hole 101 forms a closed area, and the remaining portion forms a flow area. That is, no through holes are formed on the portion of the second flat wall 21c opposite to the injection hole 101. When electrolyte is injected, it first contacts the closed area, is buffered by the closed area, and then flows to the flow area. Finally, it is injected into the battery casing 4 through the liquid passage hole in the flow area.

[0045] For ease of distinction, the liquid passage holes located in the flow area, the vertical wall 21b, and the first flat wall 21a are designated as the first liquid passage hole 211, the liquid passage hole on the vertical wall 21b as the second liquid passage hole 212, and the liquid passage hole on the first flat wall 21a as the third liquid passage hole 213. During electrolyte injection, the electrolyte first flows into the housing through the first liquid passage hole. Once the electrolyte volume in the first groove 21 reaches a certain level, it then flows into the housing through the second and third liquid passage holes.

[0046] Continue to combine Figures 1 to 3 As shown, in some exemplary embodiments, the electrolyte passages are, for example, a plurality of spaced-apart holes, which can further improve the electrolyte injection efficiency. Additionally, in some exemplary embodiments, the electrolyte passages are, for example, round holes, elongated holes, or rectangular holes, which have a simpler structure and are easier to fabricate on the lower plastic part 2.

[0047] In specific implementation, the first liquid passage 211 and the third liquid passage 213 are multiple passages arranged at intervals along both the length and width directions of the lower plastic part 2. The second liquid passage 212 is preferably an elongated hole, which partially penetrates the second flat wall 21c and partially penetrates the vertical wall 21b, thus reducing the amount of electrolyte remaining in the first groove 21. Alternatively, the second liquid passage 212 can also partially penetrate the first flat wall 21a, which also reduces the amount of electrolyte remaining at the first flat wall 21a.

[0048] It should be noted that, in addition to round, elongated, or rectangular holes, other irregularly shaped holes can also be used for the liquid passage.

[0049] Combination Figures 4 to 8 As shown, in some exemplary embodiments, for example, in the thickness direction of the lower plastic part 2, the distance L between the first straight wall 21a and the second straight wall 21c is between 0.5mm and 5mm. In specific embodiments, the distance L between the first straight wall 21a and the second straight wall 21c is 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm, etc.

[0050] Here, by limiting the distance between the first straight wall 21a and the second straight wall 21c, it can be effectively ensured that the first straight wall 21a and the electrode group maintain a certain distance. This allows the electrolyte to pass smoothly through the liquid passage holes on the vertical wall 21b and the first straight wall 21a, thereby improving the electrolyte injection efficiency. At the same time, the portion of the first groove 21 corresponding to the first straight wall 21a can also further buffer the electrolyte during the injection process.

[0051] Based on the liquid passage holes provided on the bottom wall of the first groove 21, combined with Figures 4 to 6 As shown, in some exemplary embodiments, a through hole 220 is also provided on the bottom wall of the second groove 22. In this case, the injected electrolyte can enter the second groove 22 through the through hole 220, which can, to a certain extent, serve to store the electrolyte, thereby increasing the amount of electrolyte injected and thus improving the battery's lifespan.

[0052] Combined Figures 4 to 6 As shown, in some exemplary embodiments, for example, a pole mounting portion 23 is provided on the lower plastic part 2, which is located between the first groove 21 and the second groove 22 and is disposed close to the second groove 22.

[0053] Specifically, the pole mounting part 23 includes a mounting hole formed on the lower plastic part 2. The pole 3 passes through the mounting hole and the through hole on the cover plate body 1 in sequence, and is riveted together with the riveting block to realize the installation of the pole 3.

[0054] In the above embodiment, by providing an electrode mounting part 23 on the lower plastic part 2 and positioning the electrode mounting part 23 close to the second groove 22, the electrode 3 mounted on the electrode mounting part 23 can be moved away from the position of the injection hole 101, thereby preventing electrolyte from overflowing and contaminating the surface of the cover plate body 1 and the electrode 3 during injection.

[0055] See Figure 6As shown, in some exemplary embodiments, for example, on the side of the lower plastic part 2 away from the cover plate, a first cavity 24 and a second cavity 25 are formed on the lower plastic part 2, with the first cavity 24 and the second cavity 25 respectively disposed on both sides of the pole mounting portion 23. Furthermore, both the first cavity 24 and the second cavity 25 are provided with reinforcing ribs. In this case, the first cavity 24 and the second cavity 25 provided on the lower plastic part 2 help to reduce the overall weight of the lower plastic part 2, and the reinforcing ribs can improve the overall structural strength of the lower plastic part 2.

[0056] Specifically, as an example structure, the reinforcing rib includes, for instance, a first reinforcing rib 231 and a second reinforcing rib 232 connected horizontally and vertically. The first reinforcing rib 231 extends along the length direction of the lower plastic part 2, and the second reinforcing rib 232 extends along the width direction of the lower plastic part 2. The connected first reinforcing rib 231 and second reinforcing rib 232 can further improve the structural strength of the lower plastic part 2.

[0057] In this embodiment, the first cavity 24 is provided with a first reinforcing rib 231 and a second reinforcing rib 232. The second cavity 25, due to its smaller size, only contains the first reinforcing rib 231. It is worth noting that, besides providing reinforcing ribs in both the first and second cavities 24 and 25, it is also possible to provide reinforcing ribs only in the first cavity 24 or only in the second cavity 25. The reinforcing ribs provided in the first cavity 24 can be as follows: Figure 6 As shown, it includes a first reinforcing rib 231 and a second reinforcing rib 232, but it may also only have the first reinforcing rib 231 or only the second reinforcing rib 232. The reinforcing ribs provided in the second cavity 25 may also include the first reinforcing rib 231 and the second reinforcing cavity, and the specific configuration can be made according to actual needs. This embodiment does not limit this.

[0058] In addition, it should be noted that the lower plastic part 2 in this embodiment is integrally formed by injection molding. On the one hand, this can ensure the insulation of the lower plastic part 2, and on the other hand, it is convenient to form the required first groove 21, second groove 22, pole mounting part 23, first cavity 24 and second cavity 25, and reinforcing ribs on the lower plastic part 2 during remanufacturing.

[0059] Combination Figures 7 to 10As shown, in some exemplary embodiments, the cover assembly further includes a sealing plug 5 and a sealing cap 6 disposed at the injection hole 101. The injection hole 101 is, for example, a stepped hole with a first hole 10, a second hole 20, and a third hole 30 communicating along the injection direction. A first stepped surface is formed between the first hole 10 and the second hole 20, and a second stepped surface is formed between the second hole 20 and the third hole 30. The sealing plug 5 is interference-fitted into the third hole 30, and one end of the sealing plug 5 is confined to the second stepped surface. The sealing cap 6 is disposed in the first hole 10 and welded to the cover body 1.

[0060] By setting the sealing plug 5 in the third hole 30 of the injection hole 101 with an interference fit, and limiting one end of the sealing plug 5 to the second step surface, the sealing performance at the injection hole 101 can be effectively improved. At the same time, in conjunction with the welding connection between the sealing cap 6 and the cover plate body 1, the sealing performance at the injection hole 101 can be further improved.

[0061] Specifically, the structure of the sealing plug 5 is as follows: Figure 7 and Figure 9 As shown, for example, the sealing plug 5 includes a main body 51 that is interference-fitted into the third hole 30, and a limiting flange 52 connected to one end of the main body 51. The limiting flange 52 is disposed near the sealing cover 6 and can abut against the second step surface. In a specific implementation, the sealing plug 5 is driven into the third hole 30 by a nailing device. At this time, the limiting protrusion 611 not only increases the contact area with the nailing device, which helps to ensure the assembly quality of the sealing plug 5 in the third hole 30, but also prevents the sealing plug 5 from extending excessively into the third hole 30, affecting the sealing performance of the injection hole 101.

[0062] Meanwhile, in this embodiment, a limiting protrusion 611 is also provided on the side of the sealing cover 6 facing the sealing plug 5. The limiting protrusion 611 can restrict the movement of the sealing plug 5 in the direction pointing outward from the cover body 1. At this time, the setting of the limiting protrusion 611 can generate gas inside the battery. When the gas pressure presses against the sealing plug 5, it can effectively prevent the sealing plug 5 from moving in the direction outward from the cover body 1. Moreover, combined with the limiting effect between the limiting protrusion 52 and the second step surface, bidirectional limiting of the sealing plug 5 can be achieved, effectively limiting the axial displacement of the sealing plug 5, so that the sealing plug 5 is always in the optimal sealing position.

[0063] In terms of specific structure, the sealing cover 6 has a cover body 61 with a sealing plug 5 and a connecting edge 62 provided around the cover body 61. The connecting protrusion is installed in the first hole 10, and the connecting edge 62 abuts against the first step surface. The sealing cover 6 is welded to the cover plate body 1 through the connecting edge 62.

[0064] Still combined Figures 7 to 10As shown, in some exemplary embodiments, a limiting groove 520 is provided on the limiting flange 52, and the limiting protrusion 611 can be inserted into the limiting groove 520. Specifically, a limiting groove 520 corresponding to the limiting protrusion 611 is provided on the end face of the sealing plug 5, so that the limiting protrusion 611 can be inserted into the limiting groove 520. In this way, by utilizing the cooperation between the limiting protrusion 611 and the limiting groove 520, when the gas pressure inside the cell pushes the plug, it can effectively prevent the sealing plug 5 from moving in the opposite direction to the liquid injection direction, further ensuring the positional reliability and sealing performance of the sealing plug 5.

[0065] It is worth noting that, regarding the cover plate assembly of this embodiment, based on the above exemplary embodiments, in specific implementation, as a preferred embodiment, it is still composed of... Figures 1 to 10 As shown, it may include, for example, a cover plate body 1 and a lower plastic part 2 connected to one side of the cover plate body 1. The lower plastic part 2 has a first groove 21 and a second groove 22 at both ends along the length direction, and the bottom of the first groove 21 and the bottom of the second groove 22 are used to limit the electrode assembly inside the battery housing 4.

[0066] The first groove 21 is correspondingly provided with the injection hole 101 on the cover plate body 1, and the bottom wall of the first groove 21 is stepped, and has a first flat wall 21a and a second flat wall 21c arranged at intervals along the injection direction, and a vertical wall 21b connecting the first flat wall 21a and the second flat wall 21c. The second flat wall 21c has a closed area opposite to the injection hole 101, and a flow area other than the closed area. The flow area, the vertical wall 21b and the first flat wall 21a are all provided with liquid passage holes.

[0067] In the thickness direction of the lower plastic part 2, the distance L between the first straight wall 21a and the second straight wall 21c is between 0.5mm and 5mm.

[0068] The bottom wall of the second groove 22 is provided with a through hole 220. The liquid passage holes formed on the first flat wall 21a, the vertical wall 21b and the second flat wall 21c are arranged in multiple intervals, and each liquid passage hole is a round hole, an elongated hole or a rectangular hole.

[0069] The lower plastic part 2 is provided with an electrode mounting portion 23, which is located between the first groove 21 and the second groove 22, and is positioned close to the second groove 22. On the side of the lower plastic part 2 away from the cover plate, that is, the side of the lower plastic part 2 facing the electrode assembly, a first cavity 24 and a second cavity 25 are formed, which are respectively located on both sides of the electrode mounting portion 23. Reinforcing ribs are provided in the first cavity 24 and the second cavity 25.

[0070] The cover plate body 1 is further provided with a sealing plug 5 and a sealing cap 6 at the injection hole 101. The injection hole 101 is a stepped hole and has a first hole 10, a second hole 20 and a third hole 30 that are connected along the injection direction. A first stepped surface is formed between the first hole 10 and the second hole 20, and a second stepped surface is formed between the second hole 20 and the third hole 30. The sealing plug 5 specifically includes a main body 51 that is interference-fitted into the third hole 30, and a limiting flange 52 provided at one end of the main body 51, which can abut against the second stepped surface.

[0071] The sealing cover 6 is located in the first hole 10, and the side of the sealing cover 6 facing the sealing plug 5 is provided with a limiting protrusion 611. The limiting protrusion 611 can restrict the movement of the sealing plug 5 in the direction pointing to the outside of the cover plate body 1.

[0072] In the preferred embodiment of the cover plate assembly described above, the specific settings and arrangements of the first groove 21 and the second groove 22, the sealing plug 5, the sealing cap 6, and the mating structures of the sealing plug 5 and the sealing cap 6 with the injection hole 101 on the lower plastic part 2 can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the first groove 21 and the second groove 22, the sealing plug 5, the sealing cap 6, and the mating structures of the sealing plug 5 and the sealing cap 6 with the injection hole 101 on the lower plastic part 2 can also be referred to the descriptions in the above exemplary embodiments.

[0073] The cover plate assembly of this embodiment adopts the above design. By setting a first groove 21 with a stepped bottom wall and utilizing the set closed area, it can buffer the electrolyte and effectively avoid damage to the electrode assembly caused by the electrolyte injection pressure. Moreover, this structural form can also allow for a larger dimension of the electrode tab portion in the length direction of the lower plastic part 2, and the electrolyte passage will not be blocked by the electrode tab during battery vacuuming, thereby ensuring the smooth progress and efficiency of the vacuuming operation.

[0074] An embodiment of the second aspect of this application provides a battery having a cover assembly as described above.

[0075] The battery in this embodiment, by adopting the above-mentioned cover plate assembly, can not only avoid damage to the electrode assembly caused by the electrolyte injection pressure during electrolyte injection, but also ensure the smooth progress and efficiency of the battery vacuuming operation, thereby improving the battery production efficiency and manufacturing quality.

[0076] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A cover plate assembly, characterized in that: Includes a cover plate body and a lower plastic part disposed on one side of the cover plate body; The lower plastic part has a first groove and a second groove at both ends along its length, and the bottom of the first groove and the bottom of the second groove are used to limit the electrode assembly inside the battery casing. The first groove is provided corresponding to the injection hole on the cover plate body, and the bottom wall of the first groove is stepped, and has a first flat wall and a second flat wall spaced apart along the injection direction, as well as a vertical wall connecting the first flat wall and the second flat wall. The second flat wall has a closed area opposite to the injection hole, and a flow area other than the closed area. The flow area, the vertical wall and the first flat wall are all provided with liquid passage holes.

2. The cover plate assembly according to claim 1, characterized in that: In the thickness direction of the lower plastic part, the distance L between the first straight wall and the second straight wall is between 0.5mm and 5mm.

3. The cover plate assembly according to claim 1, characterized in that: The bottom wall of the second groove has a through hole.

4. The cover plate assembly according to claim 1, characterized in that: The liquid passage holes are multiple holes arranged at intervals; and / or, The liquid passage can be a round hole, an elongated hole, or a rectangular hole.

5. The cover plate assembly according to claim 1, characterized in that: The lower plastic part is provided with an electrode mounting part; The pole mounting portion is located between the first groove and the second groove, and is positioned close to the second groove.

6. The cover plate assembly according to claim 5, characterized in that: On the side of the lower plastic part away from the cover plate, a first cavity and a second cavity are formed on the lower plastic part, and the first cavity and the second cavity are respectively disposed on both sides of the pole mounting part; The first cavity and / or the second cavity are provided with reinforcing ribs.

7. The cover plate assembly according to any one of claims 1 to 6, characterized in that: It also includes a sealing plug and a sealing cap disposed at the injection hole; The injection hole is a stepped hole and has a first hole, a second hole and a third hole that are connected along the injection direction. A first step surface is formed between the first hole and the second hole, and a second step surface is formed between the second hole and the third hole. The sealing plug is interference-fitted into the third hole, and one end of the sealing plug is limited on the second step surface. The sealing cover is disposed in the first hole and welded to the cover plate body.

8. The cover plate assembly according to claim 7, characterized in that: The sealing plug has a limiting flange at one end near the sealing cover, and the limiting flange can abut against the second step surface; The sealing cover has a limiting protrusion on the side facing the sealing plug, which can restrict the movement of the sealing plug in the direction pointing outward from the cover plate body.

9. The cover plate assembly according to claim 8, characterized in that: The limiting protrusion is provided with a limiting groove, and the limiting protrusion can be inserted into the limiting groove.

10. A battery, characterized in that: The battery includes a cover assembly as described in any one of claims 1 to 9.

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