Cover plate assembly and battery cell

Abstract

The application relates to the technical field of battery cells, and provides a cover plate assembly and a battery cell. The cover plate assembly comprises a cover plate body and a lower plastic arranged on one side of the cover plate body; one side of the lower plastic, which faces away from the cover plate body, is provided with a first boss; the first boss is provided with a first groove body; the opening of the first groove body is opposite to a liquid injection hole of the cover plate body; the groove bottom wall of the first groove body is provided with a plurality of first liquid passing holes which penetrate through the first boss; one end of the first boss, which faces away from the cover plate body, is provided with a second boss; and the plurality of first liquid passing holes are arranged around the second boss. The cover plate assembly disclosed by the application can block the tab of the pole group when vacuumizing, so that the first liquid passing holes around the tab are not easily blocked by the tab, the gas in the shell can smoothly enter the first liquid passing holes, the battery cell exhaust effect is improved, the exhaust time is shortened, and the vacuumizing efficiency of the battery cell is improved.

Description

Technical Field

[0001] This application relates to the field of battery cell technology, and in particular to a cover plate assembly and a battery cell. Background Technology

[0002] A battery cell is the smallest functional unit in a battery pack. It typically includes a housing, electrode assembly, electrolyte, and cover assembly. The electrode assembly and electrolyte are housed in the housing, and the cover assembly seals the opening in the housing. The terminals in the cover assembly connect to the tabs of the electrode assembly, allowing the cell to receive or release electrical energy through the terminals.

[0003] During the manufacturing process of the battery cell, electrolyte needs to be injected through the injection hole on the cover plate assembly and the air inside the casing needs to be evacuated. However, during the evacuation process, the tabs on the electrode assembly may move and block the injection hole. Due to the pressure difference between the inside and outside of the injection hole, the tabs will block the injection hole, which is not conducive to improving the efficiency of the battery cell evacuation. Utility Model Content

[0004] In view of this, this application aims to provide a cover plate assembly to improve the efficiency of cell vacuuming.

[0005] 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 protrusion on the side facing away from the cover plate body; The first protrusion is provided with a first groove, the opening of the first groove is directly opposite the liquid injection hole of the cover plate body, and the bottom wall of the first groove is provided with a plurality of first liquid passage holes penetrating the first protrusion. The first protrusion has a second protrusion at the end facing away from the cover plate body, and a plurality of the first liquid passage holes are arranged around the second protrusion.

[0006] Furthermore, a second tank is formed by a recess in the middle of the bottom wall of the first tank. A second liquid passage hole is provided on the bottom wall of the second tank at a location not directly opposite the injection hole, and the second liquid passage hole penetrates the second boss.

[0007] Furthermore, the first protrusion is provided with an annular baffle arranged around the second protrusion. The first protrusion, the second protrusion, and the annular baffle form an exhaust channel. One side of the annular baffle is provided with a notch for gas to pass through.

[0008] Furthermore, a first reinforcing rib is provided between the second boss and the annular retaining edge, and the first reinforcing rib does not extend beyond the annular retaining edge in the thickness direction of the lower plastic.

[0009] Furthermore, the reinforcing ribs are arranged in a plurality of positions surrounding the second boss, and the first liquid passage hole is provided between any adjacent reinforcing ribs.

[0010] Furthermore, the annular flange and the second boss are arranged flush with each other in the thickness direction of the lower plastic.

[0011] Furthermore, a third protrusion is provided on the side of the lower plastic facing away from the cover plate body, and the first protrusion and the third protrusion are respectively located at both ends of the lower plastic in its own length direction. The second protrusion and the third protrusion can jointly abut against the electrode assembly inside the battery cell housing.

[0012] Furthermore, the third protrusion is provided with a third groove, the opening of the third groove faces the cover plate body, and the bottom of the third groove is provided with a third liquid passage hole that penetrates the third protrusion.

[0013] Furthermore, the lower plastic is provided with a mounting part for mounting the pole post. The mounting part is located between the first boss and the third boss, and is arranged close to the third boss.

[0014] Furthermore, the lower plastic part has a first cavity and a second cavity on the side opposite to the cover plate body. The first cavity and the second cavity are respectively located on both sides of the mounting part, and the first cavity and / or the second cavity are provided with a second reinforcing rib.

[0015] Compared with related technologies, this application has the following advantages: (1) The cover plate assembly described in this application, by setting a first protrusion and a first groove on the first protrusion, can provide a temporary storage space for electrolyte when electrolyte is injected into the battery cell. The first liquid passage hole is used to allow electrolyte to enter the housing or to provide a channel for gas in the housing to leave the battery cell. When vacuuming, the second protrusion can block the tabs of the electrode group, so that the first liquid passage hole around the tab is not easily blocked by the tab, and the gas in the housing can smoothly enter the first liquid passage hole. This not only helps to improve the venting effect of the battery cell, but also shortens the venting time, thereby improving the efficiency of vacuuming the battery cell.

[0016] (2) The second tank can store electrolyte. The second liquid passage hole at the bottom of the second tank can shorten the drop between the lower plastic and the electrode assembly, and reduce the impact of the electrolyte on the electrode assembly. At the same time, the second liquid passage hole is not set at the position of the bottom wall of the second tank directly opposite the injection hole. The electrolyte entering through the injection hole will not directly impact the electrode assembly. This can buffer the electrolyte and effectively reduce the damage to the electrode assembly caused by the electrolyte injection pressure.

[0017] (3) When the electrolyte is injected, the lower plastic is in the state of the first boss facing down. When vacuuming, some of the gas in the shell can enter the exhaust channel formed between the annular baffle, the first boss and the second boss through the notch. The gas entering the exhaust channel is finally discharged through the first liquid passage, which is beneficial to improve the exhaust effect. At the same time, the annular baffle can also enhance the structural strength of the lower plastic.

[0018] (4) The first reinforcing rib can enhance the structural strength of the lower plastic and improve its resistance to deformation. Setting the first reinforcing rib in the form of a ring-shaped baffle that does not protrude in the thickness direction of the lower plastic can ensure the smooth flow of the exhaust channel and prevent it from being blocked by the first reinforcing rib.

[0019] (5) Setting the first reinforcing ribs as multiple ones surrounding the second boss can further enhance the support effect on the second boss and the annular baffle. Setting the first liquid passage hole between adjacent first reinforcing ribs can better discharge the air between adjacent first reinforcing ribs. Arranging the annular baffle and the second boss flush in the lower plastic thickness direction can make the two together press the electrode group and improve the fixing effect of the electrode group.

[0020] (6) A third protrusion is provided, and the first protrusion and the third protrusion are placed at both ends of the lower plastic length direction, so that the second protrusion and the third protrusion can cooperate to press the two ends of the electrode group respectively, which is beneficial to improve the fixing effect of the electrode group, making the electrode group less prone to movement and more stable.

[0021] (7) A third tank is set on the third protrusion, and a third liquid passage hole is set on the bottom wall of the third tank. The electrolyte can enter the third tank through the third liquid passage hole. The third tank can store the electrolyte, which is equivalent to increasing the electrolyte injection volume of the battery cell, which is beneficial to improving the service life of the battery cell.

[0022] (8) By setting the mounting part on the lower plastic, the mounting part can be set close to the third tank body. This allows the electrode post installed on the mounting part to be far away from the position of the liquid injection hole, so that the overflowing electrolyte will not easily contaminate the electrode post during liquid injection.

[0023] (9) Setting the first cavity and the second cavity on the lower plastic can reduce the weight of the lower plastic, which is beneficial to the lightweight design of the battery cell. At the same time, setting the second reinforcing rib can enhance the structural strength of the lower plastic at the first cavity and / or the second cavity.

[0024] Another object of this application is to provide a battery cell having the aforementioned cover plate assembly.

[0025] The battery cell described in this application, by setting the aforementioned cover plate assembly, ensures that the electrode tabs of the electrode group are blocked by the second protrusion during vacuuming, thus preventing blockage of the first liquid passage hole. This allows the first liquid passage hole to release gas normally, improving the venting effect and efficiency, and consequently enhancing the production efficiency of the battery cell. Attached Figure Description

[0026] 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 an overall schematic diagram of the cover plate assembly described in the embodiments of this application; Figure 2 This is an overall schematic diagram of the cover plate assembly described in an embodiment of this application from another perspective; Figure 3 This is a top view of the cover plate assembly described in an embodiment of this application; Figure 4 for Figure 3 Sectional view at point AA; Figure 5 This is a schematic diagram of the lower plastic structure described in the embodiments of this application; Figure 6 This is a schematic diagram of the lower plastic structure from another perspective, as described in an embodiment of this application. Figure 7 This is a schematic diagram of the structure of the injection hole as described in the embodiment of this application; Figure 8 This is an overall schematic diagram of the battery cell described in the embodiments of this application; Explanation of reference numerals in the attached figures: 1. Cover plate body; 101. Injection hole; 1011. Inner hole; 1012. Outer hole; 2. Lower plastic part; 201. First boss; 202. First groove; 203. First liquid passage hole; 204. Second boss; 205. Second groove; 206. Second liquid passage hole; 207. Annular flange; 2071. Notch; 208. First reinforcing rib; 209. Third boss; 210. Third groove; 211. Third liquid passage hole; 212. Mounting part; 213. First cavity; 214. Second cavity; 215. Second reinforcing rib; 2151. Structural rib; 2152. Limiting rib; 3. Electrode assembly; 301. Electrode tab; 4. Housing; 401. Explosion-proof valve; 5. Sealing plug; 6. Sealing cap; 601. Protrusion; 7. Pole post; 8. Insulating film; a. Exhaust passage. Detailed Implementation

[0027] 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.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] An embodiment of the first aspect of this application provides a cover plate assembly to improve the efficiency of cell vacuuming.

[0034] In related technologies, a battery cell is the smallest functional unit in a battery pack. It typically includes a casing, electrode assembly, electrolyte, and cover assembly. The electrode assembly and electrolyte are housed in the casing, and the cover assembly seals the opening in the casing. The terminals in the cover assembly connect to the tabs of the electrode assembly, allowing the battery cell to receive or release electrical energy through the terminals.

[0035] During the manufacturing process of the battery cell, electrolyte needs to be injected through the injection hole on the cover plate assembly and the air inside the casing needs to be evacuated. However, during the evacuation process, there will be a negative pressure inside the casing. The tabs on the electrode assembly may move and block the injection hole. Due to the pressure difference between the inside and outside of the injection hole, the tabs will block the injection hole, affecting the air release from the injection hole and hindering the efficiency of the battery cell evacuation.

[0036] 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 6 In terms of content and overall design, it includes a cover plate body 1 and a lower plastic 2 located on one side of the cover plate body 1.

[0037] The lower plastic 2 has a first protrusion 201 on the side facing away from the cover plate body 1. The first protrusion 201 has a first groove 202, the opening of which faces the liquid injection hole 101 of the cover plate body 1. The bottom wall of the first groove 202 has multiple first liquid passage holes 203 penetrating the first protrusion 201. The end of the first protrusion 201 facing away from the cover plate body 1 has a second protrusion 204, and the multiple first liquid passage holes 203 are arranged around the second protrusion 204.

[0038] Therefore, by setting the first protrusion 201 and the first groove 202 on the first protrusion 201, a temporary storage space for electrolyte can be provided when electrolyte is injected into the battery cell. The first liquid passage 203 is used to allow electrolyte to enter the housing 4 or to provide a channel for gas in the housing 4 to leave the battery cell. When vacuuming, the second protrusion 204 can block the tabs 301 of the electrode group 3, so that the first liquid passage 203 around the tabs 301 is not easily blocked by the tabs 301, and the gas in the housing 4 can smoothly enter the first liquid passage 203. This not only helps to improve the venting effect of the battery cell, but also shortens the venting time, thereby improving the efficiency of vacuuming the battery cell.

[0039] Based on the above overview, specifically, the cover plate body 1 is welded to the battery cell housing 4, forming a sealed inner cavity that accommodates the electrode assembly 3 and the electrolyte. The lower plastic 2 is located on the side of the cover plate facing inwards from the housing 4 and is sandwiched between the cover plate body 1 and the housing 4, serving to protect the battery cell structure, provide electrical insulation, and cushion and absorb shock.

[0040] Continue to combine Figures 1 to 6As shown, in some exemplary embodiments, the middle of the bottom wall of the first tank 202 is recessed to form a second tank 205, and a second liquid passage hole 206 is provided on the bottom wall of the second tank 205 at a position not directly opposite to the liquid injection hole 101, and the second liquid passage hole 206 penetrates the second boss 204.

[0041] In this embodiment, the second tank 205 is provided to store electrolyte and serves as a part that directly receives the electrolyte injected through the injection hole 101. The second liquid passage hole 206 at the bottom of the second tank 205 can shorten the drop between the lower plastic 2 and the electrode assembly 3, thereby reducing the impact of the electrolyte on the electrode assembly 3.

[0042] Meanwhile, the second liquid passage 206 is not provided on the bottom wall of the second tank 205 at the position directly opposite the liquid injection hole 101. The electrolyte entering through the liquid injection hole 101 will not directly impact the electrode assembly 3. In this way, the bottom wall of the second tank 205 can buffer the electrolyte, which can effectively reduce the damage caused by the electrolyte injection pressure to the electrode assembly 3, and help improve the service life and safety of the electrode assembly 3.

[0043] Preferably, the first tank 202 and the second tank 205 can be configured as rectangular tanks, with the opening edge of the second tank 205 equidistant from the sidewall of the first tank 202, which facilitates uniform diffusion of the electrolyte. The first through-holes 203 can be arranged in a dense pattern around the second protrusion 204 to increase the flow rate of electrolyte and gas. Similarly, second through-holes 206 can be densely arranged on the bottom wall of the second tank 205 at locations not directly opposite the injection hole 101 to increase the electrolyte flow rate at those locations. The second through-holes 206 can be arranged in a rectangular array.

[0044] Reference Figure 2 , Figure 4 and Figure 6 As shown, in some exemplary embodiments, the first boss 201 is provided with an annular baffle 207 arranged around the second boss 204. The first boss 201, the second boss 204 and the annular baffle 207 form an exhaust channel a. One side of the annular baffle 207 is provided with a notch 2071 for gas to pass through.

[0045] With this configuration, when the electrolyte is injected, the lower plastic 2 is in a state where the first protrusion 201 faces downward. When vacuuming, some of the gas inside the shell 4 can enter the exhaust channel a formed between the annular baffle 207, the first protrusion 201, and the second protrusion 204 through the notch 2071. The gas entering the exhaust channel a is finally discharged through the first liquid passage 203, which helps to improve the exhaust effect. At the same time, the annular baffle 207 can also enhance the structural strength of the lower plastic 2.

[0046] It is understandable that the exhaust channel a is arranged around the second protrusion 204, and the gas in the exhaust channel a is eventually discharged through the first liquid passage 203. During vacuuming, if there is also gas outside the second liquid injection hole 101, the second liquid injection hole 101 can also guide the gas out of the battery cell.

[0047] Continue to refer to Figure 2 , Figure 4 and Figure 6 As shown, in some exemplary embodiments, based on the presence of annular flange 207, a first reinforcing rib 208 is provided between the second boss 204 and the annular flange 207. The first reinforcing rib 208 does not extend beyond the annular flange 207 in the thickness direction of the lower plastic 2. The first reinforcing rib 208 can be integrally injection molded with the first boss 201, the annular flange 207, and the second boss 204.

[0048] In this way, the first reinforcing rib 208 can enhance the structural strength of the lower plastic 2 and improve its resistance to deformation, which is beneficial to extending the service life of the battery cell. In addition, setting the first reinforcing rib 208 to not protrude from the annular retaining edge 207 in the thickness direction of the lower plastic 2 can ensure the unobstructed flow of the exhaust channel a and prevent it from being blocked by the first reinforcing rib 208, which is beneficial to improving the exhaust effect.

[0049] In addition to the first reinforcing rib 208, in some exemplary embodiments, the reinforcing ribs are arranged as a plurality of ribs surrounding the second boss 204, and a first liquid passage hole 203 is provided between any adjacent reinforcing ribs.

[0050] According to this embodiment, the first reinforcing rib 208 is configured as multiple ribs surrounding the second protrusion 204, which can further enhance the support effect on the second protrusion 204 and the annular retaining edge 207. The first liquid passage hole 203 is provided between adjacent first reinforcing ribs 208, so that the air between each adjacent first reinforcing rib 208 can be vented through the corresponding first liquid passage hole 203, which helps to reduce dead angles during vacuuming and allows the gas in the battery cell to be better discharged.

[0051] Still refer to Figure 2 , Figure 4 and Figure 6 As shown, in some exemplary embodiments, the annular flange 207 and the second boss 204 are arranged flush with each other in the thickness direction of the lower plastic 2.

[0052] It should be noted that the flushing of the annular retaining edge 207 and the second protrusion 204 refers to the part of the annular retaining edge 207 facing away from the cover plate body 1 (excluding the notch 2071) being flush with the end of the second protrusion 204 facing away from the cover plate body 1. In this way, the annular retaining edge 207 and the second protrusion 204 can form a larger plane for pressing the electrode assembly 3, which is beneficial to improving the fixing effect of the electrode assembly 3.

[0053] See Figures 1 to 6 In some exemplary embodiments, the lower plastic 2 has a third protrusion 209 on the side facing away from the cover body 1, and the first protrusion 201 and the third protrusion 209 are respectively located at both ends of the lower plastic 2 in its length direction. The second protrusion 204 and the third protrusion 209 can jointly abut against the electrode group 3 inside the battery cell housing 4.

[0054] By setting the third protrusion 209, and positioning the first protrusion 201 and the third protrusion 209 at opposite ends along the length of the lower plastic 2, the second protrusion 204 and the third protrusion 209 can cooperate to press against both ends of the electrode assembly 3, thus improving the fixation effect on the electrode assembly 3, making it less prone to shifting and ensuring better stability. Specifically, the third protrusion 209 can be set as a cuboid, with the same width as the lower plastic 2 in the width direction, which can better fit the inner wall of the housing 4.

[0055] Based on the provision of the third boss 209, in some exemplary embodiments, the third boss 209 is provided with a third groove 210, the opening of the third groove 210 faces the cover plate body 1, and the bottom of the third groove 210 is provided with a third liquid passage hole 211 that penetrates the third boss 209.

[0056] By setting a third tank 210 on the third boss 209 and setting a third liquid passage hole 211 on the bottom wall of the third tank 210, the electrolyte can enter the third tank 210 through the third liquid passage hole 211. The third tank 210 can play the role of storing electrolyte, which is equivalent to increasing the electrolyte injection volume of the battery cell and is beneficial to improving the service life of the battery cell.

[0057] In practical implementation, the dimension of the third protrusion 209 in the length direction of the lower plastic 2 can be set to be smaller than that of the first protrusion 201, which helps to reduce the weight and volume of the lower plastic 2. Secondly, the end of the third protrusion 209 facing away from the cover plate body 1 can be flush with the end of the second protrusion 204 facing away from the cover plate body 1, which helps to improve the firmness of the compression fixation of the electrode assembly 3.

[0058] Continue to refer to Figures 1 to 6In some exemplary embodiments, the lower plastic 2 is provided with a mounting portion 212 for mounting the pole post 7. The mounting portion 212 is located between the first boss 201 and the third boss 209 and is arranged close to the third boss 209.

[0059] It is understandable that by providing the mounting part 212 on the lower plastic 2, the mounting part 212 can be positioned close to the third tank 210. This allows the electrode post 7 mounted on the mounting part 212 to be located away from the position of the injection hole 101, thereby preventing the overflowing electrolyte from contaminating the electrode post 7 during injection.

[0060] Specifically, the mounting part 212 may include mounting holes formed on the lower plastic 2. The pole post 7 passes through the mounting holes and the through holes on the cover plate body 1 in sequence, and is riveted together with the riveting block to realize the installation of the pole post 7.

[0061] Reference Figure 2 and Figure 6 In some exemplary embodiments, the lower plastic 2 has a first cavity 213 and a second cavity 214 on the side opposite to the cover plate body 1. The first cavity 213 and the second cavity 214 are respectively located on both sides of the mounting part 212, and a second reinforcing rib 215 is provided in both the first cavity 213 and the second cavity 214.

[0062] As described above, in this embodiment, the lower plastic 2 is provided with a first cavity 213 and a second cavity 214, which can reduce the weight of the lower plastic 2 and is beneficial to the lightweight design of the battery cell. At the same time, the second reinforcing rib 215 is provided to enhance the structural strength of the lower plastic 2 at the first cavity 213 and the second cavity 214.

[0063] Of course, the second reinforcing rib 215 can also be provided only in the first cavity 213 or the second cavity 214, but the structural reinforcement effect on the lower plastic 2 is not as good as the above-described implementation.

[0064] Specifically, the second reinforcing rib 215 may include, for example, a structural rib 2151 extending along the length of the lower plastic 2, and a limiting rib 2152 for defining the position of the rivet block. The two sides of the limiting rib 2152 are connected to the first boss 201 and the third boss 209 respectively through the structural rib 2151.

[0065] In this embodiment, the first liquid passage 203, the second liquid passage 206, and the third liquid passage 211 can all be circular holes. Of course, in addition to circular holes, elongated holes, rectangular holes, or other irregularly shaped holes can also be used.

[0066] Additionally, refer to Figure 7 In some embodiments, the injection hole 101 includes an outer hole 1012 and an inner hole 1011 connected sequentially along the injection direction, wherein the diameter of the outer hole 1012 is larger than that of the inner hole 1011.

[0067] The inner hole 1011 is press-fitted with a sealing plug 5, and the outer hole 1012 is welded with a sealing cap 6. The sealing cap 6 has a protrusion 601 on the side facing the sealing plug 5. The protrusion 601 can abut against the sealing plug 5, making it difficult for the sealing plug 5 to detach from the inner hole 1011. The protrusion 601 can be, for example, cylindrical in shape.

[0068] 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 7 As shown, it may include, for example, a cover body 1 with pole post 7, and a lower plastic 2 installed on the side of the cover body 1 facing the housing 4.

[0069] Among them, the lower plastic 2 has a first protrusion 201 and a third protrusion 209 on the side facing away from the cover plate body 1, and a second protrusion 204 on the side of the first protrusion 201 facing away from the cover plate body 1. The second protrusion 204 is flush with the third protrusion 209.

[0070] The first boss 201 is provided with a first groove 202, and the bottom wall of the first groove 202 is recessed into the second boss 204 to form a second groove 205. The bottom wall of the first groove 202 is provided with a first liquid passage hole 203, and the bottom wall of the second groove 205 is provided with a second liquid passage hole 206 at a part that is not directly opposite to the liquid injection hole 101.

[0071] The first boss 201 is provided with an annular baffle 207 arranged around the second boss 204. The annular baffle 207, the first boss 201 and the second boss 204 form an exhaust channel a. The annular baffle 207 is provided with a notch 2071.

[0072] The third boss 209 is provided with a third tank 210, and the bottom wall of the third tank 210 is provided with a third liquid passage hole 211.

[0073] In the preferred embodiment of the above cover plate assembly, the specific settings and arrangements of the cover plate body 1, the lower plastic 2, etc. 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 cover plate body 1, the lower plastic 2, etc. can also be referred to the descriptions in the above exemplary embodiments.

[0074] The cover plate assembly of this embodiment adopts the above design. By setting a first protrusion 201 and a first groove 202 on the first protrusion 201, it can provide a temporary storage space for electrolyte when electrolyte is injected into the battery cell. The first liquid passage 203 is used to allow electrolyte to enter the housing 4 or to provide a channel for gas in the housing 4 to leave the battery cell. During vacuuming, the second protrusion 204 can block the tabs 301 of the electrode group 3, so that the first liquid passage 203 around the tabs 301 is not easily blocked by the tabs 301, so that the gas in the housing 4 can smoothly enter the first liquid passage 203. This not only helps to improve the battery cell venting effect, but also shortens the venting time, thereby improving the efficiency of battery cell vacuuming.

[0075] An embodiment of the second aspect of this application provides a battery cell having a cover plate assembly as described in the first aspect of this application.

[0076] Specifically, refer to Figure 7 and Figure 8 As shown, the battery cell also includes a housing 4, an electrode assembly 3 disposed within the housing 4, an insulating film 8 wrapped around the electrode assembly 3, and a positive electrode cover assembly. The cover assembly of the embodiment of the first aspect of this application is used for the negative electrode of the battery cell. An explosion-proof valve 401 is provided in the middle of the housing 4.

[0077] In this embodiment of the battery cell, by setting the cover plate assembly of the first aspect of this application, when vacuuming is performed, the tabs 301 of the electrode group 3 will be blocked by the second protrusion 204 and will not easily block the first liquid passage hole 203, so that the first liquid passage hole 203 can be vented normally, which can improve the venting effect and venting efficiency, thereby helping to improve the production efficiency of the battery cell.

[0078] 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 protrusion on the side facing away from the cover plate body; The first protrusion is provided with a first groove, the opening of the first groove is directly opposite the liquid injection hole of the cover plate body, and the bottom wall of the first groove is provided with a plurality of first liquid passage holes penetrating the first protrusion. The first boss has a second boss at the end facing away from the cover plate body, and a plurality of the first liquid passage holes are arranged around the second boss.

2. The cover plate assembly according to claim 1, characterized in that: The second tank is formed by a recess in the middle of the bottom wall of the first tank. A second liquid passage hole is provided on the bottom wall of the second tank at a position not directly opposite the injection hole. The second liquid passage hole passes through the second boss.

3. The cover plate assembly according to claim 2, characterized in that: The first protrusion is provided with an annular baffle arranged around the second protrusion. The first protrusion, the second protrusion and the annular baffle form an exhaust channel. One side of the annular baffle is provided with a notch for gas to pass through.

4. The cover plate assembly according to claim 3, characterized in that: A first reinforcing rib is provided between the second boss and the annular retaining edge, and the first reinforcing rib does not extend beyond the annular retaining edge in the thickness direction of the lower plastic.

5. The cover plate assembly according to claim 4, characterized in that: The first reinforcing ribs are arranged in a plurality of configurations surrounding the second protrusion, and the first liquid passage hole is provided between any adjacent first reinforcing ribs; and / or, The annular flange and the second boss are arranged flush with each other in the thickness direction of the lower plastic.

6. The cover plate assembly according to claim 1, characterized in that: The lower plastic is provided with a third protrusion on the side facing away from the cover plate body, and the first protrusion and the third protrusion are respectively located at both ends of the lower plastic in its own length direction. The second protrusion and the third protrusion can jointly abut against the electrode assembly inside the battery cell housing.

7. The cover plate assembly according to claim 6, characterized in that: The third protrusion is provided with a third groove, the opening of the third groove faces the cover plate body, and the bottom of the third groove is provided with a third liquid passage hole that penetrates the third protrusion.

8. The cover plate assembly according to claim 6, characterized in that: The lower plastic part is provided with a mounting part for installing the pole post. The mounting part is located between the first boss and the third boss, and is arranged close to the third boss.

9. The cover plate assembly according to claim 8, characterized in that: The lower plastic part has a first cavity and a second cavity on the side opposite to the cover plate body. The first cavity and the second cavity are respectively located on both sides of the mounting part. The first cavity and / or the second cavity are provided with a second reinforcing rib.

10. A battery cell, characterized in that: The battery cell is provided with a cover plate assembly as described in any one of claims 1 to 9.

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