Cover plate assembly, battery cell and battery pack

Abstract

The application provides a cover plate assembly, an electric core and a battery pack, and relates to the technical field of batteries. The cover plate assembly comprises a cover plate, a pole, a lower plastic part and a press ring. The pole is arranged in the cover plate. The lower plastic part is arranged on one side of the cover plate. The press ring is sleeved on one end of the pole and is located on the same side of the lower plastic part. Along the radial direction of the pole, the lower plastic part and the press ring are inserted. The lower plastic part and the press ring are fixed in the circumferential direction of the pole, so that the lower plastic part is fixed relative to the press ring. The press ring is fixed relative to the cover plate through the pole, so that the lower plastic part is fixed relative to the cover plate. In this way, the lower plastic part can be prevented from rotating relative to the cover plate, so that the position stability of the lower plastic part relative to the cover plate is improved.

Description

Technical Field

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

[0002] In related technologies, a battery cell includes a housing, a cover assembly, and an electrode assembly. The cover assembly includes a cover plate, terminals, a lower plastic component, a sealing ring, and a current collector. The cover plate closes to the housing to define a receiving cavity. The electrode assembly is disposed within the receiving cavity, with the terminals passing through the cover plate and sealed and insulated from it by the sealing ring. The current collector is disposed within the receiving cavity and connects the electrode assembly to the terminals. The lower plastic component is disposed between the current collector and the cover plate and connects to the cover plate. The lower plastic component insulates and isolates the current collector and electrode assembly from the cover plate.

[0003] Currently, the lower plastic part is prone to rotation relative to the cover plate, which can easily cause friction damage and has an adverse effect on the assembly of the cover plate assembly. Utility Model Content

[0004] Embodiments of this application provide a cover plate assembly, a battery cell, and a battery pack, which can improve the positional stability of the lower plastic part relative to the cover plate.

[0005] In a first aspect, embodiments of this application provide a cover plate assembly, which includes a cover plate, an electrode post, a lower plastic component, and a pressure ring. The electrode post passes through the cover plate; the lower plastic component is disposed on one side of the cover plate; the pressure ring is sleeved on one end of the electrode post and is located on the same side of the cover plate as the lower plastic component; wherein, along the radial direction of the electrode post, the lower plastic component and the pressure ring are inserted into each other. This allows the lower plastic component and the pressure ring to engage in a stop-fitting relationship in the circumferential direction of the electrode post, thereby fixing the lower plastic component relative to the pressure ring; and the pressure ring is fixed relative to the cover plate via the electrode post, further fixing the lower plastic component relative to the cover plate. This prevents the lower plastic component from rotating relative to the cover plate, thus improving the positional stability of the lower plastic component relative to the cover plate.

[0006] In some embodiments, a concave structure is provided on the surface of the pressure ring near the lower plastic component, and a convex structure is provided on the surface of the lower plastic component near the pressure ring. The convex structure is inserted into the concave structure and fits against the inner wall of the concave structure. In this way, the pressure ring can be inserted into the lower plastic component, and the weight of the pressure ring can be reduced, which is beneficial to improving the energy density of the battery cell.

[0007] In some embodiments, the concave structure is a through groove extending along the axis of the pole post, and the convex structure is a column. One end of the column is connected to the lower plastic part, and the side of the column closest to the axis of the pole post is inserted into the through groove and fits against the inner wall of the through groove. Thus, when assembling the cover plate assembly, the lower plastic part can be installed on the cover plate first, and then the pressure ring can be moved along the axis of the cover plate to insert the pressure ring into the lower plastic part, thereby reducing the assembly difficulty of the cover plate assembly and improving the assembly efficiency of the cover plate assembly.

[0008] In some embodiments, the protruding structure is integrally formed with the lower plastic part; and / or, the column is cylindrical and the cross-section of the through groove is semi-circular. This improves the reliability of the connection between the protruding structure and the lower plastic part, thereby enhancing the structural reliability of the cover assembly.

[0009] In some embodiments, the lower plastic part is provided with a liquid passage hole, and the cover plate is provided with a liquid injection hole, with the liquid passage hole and the liquid injection hole being arranged opposite to each other. In this way, the electrode liquid injected from the liquid injection hole can flow quickly to the electrode assembly through the liquid passage hole, thereby improving the liquid injection efficiency of the battery cell.

[0010] In some embodiments, the port of the liquid through-hole facing away from the cover plate is the liquid outlet port, and the end face of the lower plastic part facing away from the cover plate is the contact end face. The liquid outlet port is located on the side of the contact end face closer to the cover plate. This creates a gap between the liquid outlet port and the electrode assembly, providing flow space for the electrolyte flowing out from the liquid outlet port. This allows the electrolyte to not only flow downwards but also move circumferentially and radially based on the gap, resulting in smoother electrolyte injection and preventing electrolyte leakage, thus improving the electrolyte injection efficiency of the battery cell.

[0011] In some embodiments, the total height of the lower plastic part along the axial direction of the electrode post is H1, and the length of the liquid passage hole is H2, satisfying: 0.3H1≤H2≤0.7H1; and / or, a groove is provided on the side of the lower plastic part away from the cover plate, and the liquid outlet port is located at the bottom of the groove. Thus, by limiting the length H2 of the liquid passage hole, on the one hand, the liquid passage hole has sufficient length to guide the flow of electrolyte, thereby improving the smoothness of electrolyte injection; on the other hand, it avoids the liquid passage hole being too large, resulting in a small gap between the liquid outlet port and the electrode assembly, thereby ensuring sufficient gap between the liquid outlet port and the electrode assembly for electrolyte flow, thus improving the electrolyte injection efficiency of the battery cell.

[0012] In some embodiments, the cover plate assembly further includes a current collector located on the side of the lower plastic part opposite to the cover plate, and the current collector is connected to the electrode post and / or pressure ring. The current collector is welded to the tabs of the electrode assembly to improve the overcurrent reliability between the electrode post and the electrode assembly.

[0013] In some embodiments, a positioning structure is provided on the surface of the lower plastic part facing the manifold, and the surface of the positioning structure facing the axis of the cover assembly contacts the manifold. Thus, when assembling the manifold to one side of the cover, the position of the manifold can be determined by the positioning structure contacting the manifold. This component can improve the assembly efficiency of the cover assembly, and the positioning structure can also limit the movement of the manifold relative to the cover, thereby ensuring the reliability of the connection between the manifold and the pole and / or pressure ring.

[0014] In some embodiments, the positioning structure is strip-shaped and extends along the length of the collector plate. This increases the mating area between the positioning structure and the collector plate, thereby improving the positioning accuracy of the positioning structure on the collector plate.

[0015] In some embodiments, the positioning structure has a length dimension L1, and the outer diameter of the lower plastic part is C, satisfying: 0.15C≤L1≤0.3C; and / or, the positioning structure has a width dimension W1 along the direction away from the collector plate, satisfying: 0.05C≤L1≤0.15C. Thus, by limiting the length dimension L1 of the positioning structure, on the one hand, sufficient mating area between the positioning structure and the collector plate can be ensured to guarantee the positional stability of the collector plate; on the other hand, the excessive length dimension L1 of the positioning structure can be avoided from affecting the arrangement of other components.

[0016] In some embodiments, there are two positioning structures, each located on one side of the collector plate, with the collector plate and the two positioning structures having a clearance fit; and / or, a groove is provided on the surface of the lower plastic part facing the collector plate, and a clearance opening is provided on the groove wall, with the positioning structure disposed within the groove, and the end of the collector plate near the pole located within the groove. This improves the ease of assembling the collector plate and the lower plastic part, thereby increasing the assembly efficiency of the cover plate assembly.

[0017] In some embodiments, a core-pressing structure is provided on the surface of the lower plastic part facing away from the cover plate. One side of the core-pressing structure is connected to the lower plastic part, and the other side is configured to contact the electrode assembly of the battery cell. In this way, the core-pressing structure can contact the electrode assembly to fix and press the electrode assembly during battery assembly, ensuring the stability of the electrode assembly.

[0018] In some embodiments, the core structure includes a first rib and a second rib, both connected to the lower plastic part. The first rib extends circumferentially along the cover plate, and the second rib extends radially along the cover plate, with one end of the second rib facing the cover plate axis connected to the first rib; and / or, the core structure includes a third rib disposed at the edge of the lower plastic part and extending circumferentially along the lower plastic part. This simplifies the core structure while allowing it to have a larger contact area with the electrode assembly, thereby improving the reliability of the lower plastic part in positioning the electrode assembly.

[0019] In some embodiments, the lower plastic part is injection molded to the cover plate; and / or, the outer diameter of the lower plastic part is smaller than the outer diameter of the surface of the cover plate near the lower plastic part. This improves, on the one hand, the tightness of the connection between the lower plastic part and the cover plate, thereby enhancing the sealing performance between them and effectively preventing electrolyte flow between them, thus improving the smoothness and efficiency of electrode fluid injection; on the other hand, it reduces assembly steps, simplifying the manufacturing process of the cover plate assembly and improving its molding efficiency and economy.

[0020] Secondly, embodiments of this application provide a battery cell comprising a housing, an electrode assembly, and the aforementioned cover assembly; the electrode assembly is disposed within the housing; the cover assembly is closed to the housing, and the electrode assembly is connected to the terminal post. This prevents the lower plastic component from rotating relative to the cover assembly, thereby improving the positional stability of the lower plastic component relative to the cover assembly and thus enhancing the reliability of the battery cell.

[0021] Thirdly, embodiments of this application provide a battery pack including the aforementioned battery cells, wherein there are multiple battery cells electrically connected to each other. This prevents the lower plastic component from rotating relative to the cover plate, thereby improving the positional stability of the lower plastic component relative to the cover plate and thus enhancing the reliability of the battery pack.

[0022] The beneficial effects of the embodiments of this application are as follows:

[0023] In the embodiments of this application, by inserting the lower plastic component and the pressure ring radially along the pole post, the lower plastic component and the pressure ring are engaged in a stop-fitting relationship in the circumferential direction of the pole post, thereby fixing the lower plastic component relative to the pressure ring; and the pressure ring is fixed relative to the cover plate through the pole post, thereby fixing the lower plastic component relative to the cover plate. This prevents the lower plastic component from rotating relative to the cover plate, thus improving the positional stability of the lower plastic component relative to the cover plate. This effectively avoids frictional damage between the lower plastic component and surrounding components when it rotates relative to the cover plate, and also ensures that the installation of the manifold is not affected during cover plate assembly, thereby improving the assembly efficiency of the cover plate assembly. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the battery pack structure provided in an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of the battery cell structure provided in an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of the structure of the cover plate assembly provided in an embodiment of this application;

[0028] Figure 4 yes Figure 3 A schematic diagram of the AA cross-sectional view after rotating 90° counterclockwise.

[0029] Figure 5 This is a schematic diagram of the structure of the lower plastic part provided in an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of the lower plastic part and the pressure ring mating according to an embodiment of this application;

[0031] Figure 7 yes Figure 4 Enlarged view of section B.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1000 - Battery pack; 201 - Housing; 202 - Housing cover;

[0034] 100-cell;

[0035] 10-Cover plate assembly; 11-Cover plate; 111-Injection hole; 12-Electrode post; 13-Lower plastic part; 131-First rib; 132-Second rib; 133-Third rib; 134-Protruding structure; 135-Liquid passage hole; 1351-Liquid outlet port; 136-Contact end face; 137-Positioning structure; 138-Groove; 139-Pressure core structure; 140-Allowing opening;

[0036] 14-Pressure ring; 141-Concave structure; 15-Sealing ring; 16-Collector's plate;

[0037] 21-Shell;

[0038] 22-Electrode assembly. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Furthermore, it should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a product that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such a product.

[0043] The following combination Figures 1 to 7 This application provides a detailed description of a cover plate assembly 10, a battery cell 100, and a battery pack 1000 provided in the embodiments of this application.

[0044] Please see Figure 1 This application provides a battery pack 1000, which includes multiple battery cells 100. The multiple battery cells 100 are electrically connected.

[0045] To meet different power demands, the battery pack 1000 can include different numbers and models of battery cells 100, with multiple battery cells 100 electrically connected, such as... Figure 1 As shown. Multiple battery cells 100 can be connected in series, parallel, or a combination thereof. A combination thereof means that some battery cells 100 are connected in series, while others are connected in parallel. Optionally, multiple battery cells 100 can first be connected in series, parallel, or a combination thereof to form a battery module, and then multiple battery modules can be connected in series, parallel, or a combination thereof to form a battery pack 1000. That is, multiple battery cells 100 can directly form a battery pack 1000, or they can first be formed into multiple battery modules, and then the multiple battery modules can be combined to form a battery pack 1000.

[0046] It is understood that the battery pack 1000 may also include a housing 201 and a cover 202. The housing 201 and the cover 202 fit together to define an installation cavity. The battery cell 100 is disposed within the installation cavity.

[0047] It is understandable that the battery pack 1000 may also include a power management system, which is also located within the mounting cavity.

[0048] Please see Figure 2 The battery cell 100 provided in the embodiments of this application includes a housing 21, an electrode assembly 22, and a cover plate assembly 10. The electrode assembly 22 is disposed inside the housing 21. The cover plate 11 of the cover plate assembly 10 covers the housing 21. The electrode assembly 22 is connected to the electrode post 12.

[0049] It is understood that the electrode assembly 22 includes a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound sequentially. The positive electrode sheet includes a positive current collector and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector; the positive current collector includes a positive current collection section and a positive tab, the positive current collection section being coated with the positive active material layer, and the positive tab not being coated with the positive active material layer. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector; the negative current collector includes a negative current collection section and a negative tab, the negative current collection section being coated with the negative active material layer, and the negative tab not being coated with the negative active material layer. The positive tab can be connected to the terminal post 12 via the current collector plate 16, and the negative tab can be directly connected to the housing 21. Thus, the terminal post 12 and the housing 21 serve as the positive and negative output terminals of the battery cell 100, respectively.

[0050] The cover plate 11 is welded and fixed to the shell 21, and the collector plate 16 is welded and fixed to the pole post 12.

[0051] Please see Figure 3 and Figure 4 This application provides a cover plate assembly 10, which includes a cover plate 11, a terminal post 12, a lower plastic component 13, and a pressure ring 14. The terminal post 12 passes through the cover plate 11. The lower plastic component 13 is disposed on one side of the cover plate 11. The pressure ring 14 is sleeved on one end of the terminal post 12 and is located on the same side of the cover plate 11 as the lower plastic component 13. The lower plastic component 13 is inserted into the pressure ring 14 along the radial direction of the terminal post 12.

[0052] The pole post 12 can be integrally formed with the pressure ring 14. When the pole post 12 and the pressure ring 14 are integrally formed, the cover plate assembly 10 also includes a terminal. The terminal is located on the side of the cover plate 11 away from the lower plastic part 13. The terminal is sleeved on the pole post 12, so that the terminal, together with the pressure ring 14, clamps the pole post 12 onto the cover plate 11.

[0053] The pressure ring 14 can also be set separately from the pole post 12. In this case, the pole post 12 has a T-shaped structure, with the large-diameter section of the pole post 12 located on the side of the cover plate 11 away from the lower plastic part 13, and the small-diameter section of the pole post 12 welded to the pressure ring 14.

[0054] It is understood that the lower plastic part 13 is located on the side of the cover plate 11 facing the electrode assembly 22. The lower plastic part 13 abuts against the electrode assembly 22 to insulate and isolate the electrode assembly 22 and the current collector 16 from the cover plate 11, and to press the electrode assembly 22 firmly to prevent the electrode assembly 22 from shaking relative to the housing of the cell 100.

[0055] It is understood that the cover plate assembly 10 may also include a sealing ring 15, which is disposed between the pole post 12 and the cover plate 11 to seal the mating part between the pole post 12 and the cover plate 11 and to insulate and isolate the pole post 12 and the cover plate 11.

[0056] It is understandable that the lower plastic part 13 and the pressure ring 14 are inserted radially along the pole post 12. This can be either the lower plastic part 13 having a protruding external structure 134 that is inserted into the pressure ring 14, or the pressure ring 14 having a protruding external structure 134 that is inserted into the lower plastic part 13.

[0057] In this embodiment, by inserting the lower plastic part 13 and the pressure ring 14 radially along the pole post 12, the lower plastic part 13 and the pressure ring 14 are engaged in a stop-fitting relationship in the circumferential direction of the pole post 12, thereby fixing the lower plastic part 13 relative to the pressure ring 14; and the pressure ring 14 is fixed relative to the cover plate 11 through the pole post 12, thereby fixing the lower plastic part 13 relative to the cover plate 11. In this way, the rotation of the lower plastic part 13 relative to the cover plate 11 can be avoided, which helps to improve the positional stability of the lower plastic part 13 relative to the cover plate 11. This can effectively avoid frictional damage between the lower plastic part 13 and surrounding components when it rotates relative to the cover plate 11, and can also ensure that the installation of the manifold 16 is not affected during the assembly of the cover plate 11, thereby improving the assembly efficiency of the cover plate assembly 10.

[0058] Please see Figure 4 In some embodiments, a concave structure 141 is provided on the surface of the pressure ring 14 near the lower plastic part 13. A convex structure 134 is provided on the surface of the lower plastic part 13 near the pressure ring 14. The convex structure 134 is inserted into the concave structure 141 and fits against the inner wall of the concave structure 141.

[0059] Specifically, the convex structure 134 is connected to the inner surface of the concave structure 141.

[0060] For example, there are two convex structures 134 and two concave structures 141. The two convex structures 134 are centrally symmetrically distributed along the axis of the pole post 12.

[0061] In this embodiment, by providing a concave structure 141 on the pressure ring 14 and a convex structure 134 on the lower plastic part 13, the pressure ring 14 can be inserted into the lower plastic part 13, and the weight of the pressure ring 14 can be reduced, which is beneficial to improving the energy density of the battery cell 100.

[0062] Please see Figure 4 In some embodiments, the concave structure 141 is a through groove extending along the axis of the pole post 12. The convex structure 134 is a column. One end of the column is connected to the lower plastic part 13, and the side of the column near the axis of the pole post 12 is inserted into the through groove and fits against the inner wall of the through groove. Thus, when assembling the cover plate assembly 10, the lower plastic part 13 can be installed on the cover plate 11 first, and then the pressure ring 14 can be moved along the axis of the cover plate 11 to insert the pressure ring 14 into the lower plastic part 13, thereby reducing the assembly difficulty of the cover plate assembly 10 and improving the assembly efficiency of the cover plate assembly 10.

[0063] Please see Figure 4 In some embodiments, the protruding structure 134 is integrally formed with the lower plastic part 13. This improves the reliability of the connection between the protruding structure 134 and the lower plastic part 13, thereby improving the structural reliability of the cover assembly 10.

[0064] Please see Figure 5 In some embodiments, the column is cylindrical, and the cross-section of the through groove is semi-circular. This reduces the sharp edges of the main body, thereby avoiding stress concentration in the protruding structure 134, which improves the stress state of the lower plastic part 13 and enhances the reliability of the cover plate assembly 10.

[0065] Correspondingly, the cross-section of the through groove is semi-circular, such as... Figure 6 As shown.

[0066] For example, the diameter of the cylinder is 1mm to 20mm. It can be understood that the diameter of the cylinder is positively correlated with the diameter of the cover plate 11, that is, the specific value of the cylinder diameter depends on the actual situation and is not fixed.

[0067] Please see Figure 4 In some embodiments, the lower plastic part 13 is provided with a liquid passage hole 135, and the cover plate 11 is provided with a liquid injection hole 111, with the liquid passage hole 135 and the liquid injection hole 111 being arranged opposite to each other. In this way, the electrode liquid injected from the liquid injection hole 111 can flow quickly to the electrode assembly 22 through the liquid passage hole 135, thereby improving the liquid injection efficiency of the battery cell 100.

[0068] The shape of the liquid passage 135 is the same as that of the liquid injection hole 111. For example, if the liquid injection hole 111 is a round hole, then the liquid passage 135 is also a round hole.

[0069] Please see Figure 4In some embodiments, the port of the liquid passage 135 facing away from the cover plate 11 is the liquid outlet port 1351. The end face of the lower plastic part 13 facing away from the cover plate 11 is the contact end face 136. The liquid outlet port 1351 is located on the side of the contact end face 136 closer to the cover plate 11. In this way, a gap is formed between the liquid outlet port 1351 and the electrode assembly 22, thereby providing flow space for the electrolyte flowing out from the liquid outlet port 1351. This allows the electrolyte to not only flow downwards but also move circumferentially and radially based on the gap, thus making the electrolyte injection smoother and preventing electrolyte leakage, which helps to improve the electrolyte injection efficiency of the battery cell 100.

[0070] Please see Figure 7 In some embodiments, the total height of the lower plastic part 13 along the axial direction of the pole post 12 is H1, and the length of the liquid passage hole 135 is H2, satisfying: 0.3H1≤H2≤0.7H1.

[0071] It is understood that the length dimension H2 of the liquid passage 135 includes, but is not limited to, 0.301, 0.31H1, 0.32H1, 0.33H1, 0.34H1, 0.35H1, 0.36H1, 0.37H1, 0.38H1, 0.39H1, 0.4H1, 0.41H1, 0.42H1, 0.43H1, 0.44H1, 0.45H1, 0.46H1, 0.47H1, 0.49H1, 0.51H1, 0.53H1, 0.55H1, 0.57H1, 0.59H1, 0.61H1, 0.63H1, 0.65H1, 0.67H1, 0.68H1, 0.69H1, and 0.7H1.

[0072] In this embodiment, by limiting the length H2 of the liquid passage 135, on the one hand, the liquid passage 135 can have a sufficient length to guide the flow of electrolyte, thereby improving the smoothness of electrolyte injection. On the other hand, it can prevent the length of the liquid passage 135 from being too large, which would result in a small gap between the liquid outlet port 1351 and the electrode assembly 22. This ensures that there is a sufficient gap between the liquid outlet port 1351 and the electrode assembly 22 for electrolyte flow, thereby improving the electrolyte injection efficiency of the cell 100.

[0073] A groove 138 is provided on the side of the lower plastic part 13 away from the cover plate 11, and the liquid outlet port 1351 is located at the bottom of the groove 138.

[0074] Please see Figure 3 or Figure 4 In some embodiments, the cover plate assembly 10 further includes a manifold 16. The manifold 16 is located on the side of the lower plastic part 13 opposite to the cover plate 11. The manifold 16 is connected to the pole post 12 and / or the pressure ring 14.

[0075] For example, the manifold 16 is welded to the pole post 12, or the manifold 16 is welded to the pressure ring 14, or the manifold 16 is welded to both the pole post 12 and the pressure ring 14.

[0076] It is understandable that the tabs of the current collector 16 and the electrode assembly 22 are welded together to improve the overcurrent reliability between the electrode post 12 and the electrode assembly 22.

[0077] Please see Figure 3 , Figure 5 as well as Figure 6 In some embodiments, a positioning structure 137 is provided on the surface of the lower plastic part 13 facing the manifold 16. The surface of the positioning structure 137 facing the axis of the cover assembly 10 contacts the manifold 16. Thus, when assembling the manifold 16 to one side of the cover 11, the position of the manifold 16 can be determined by the contact between the positioning structure 137 and the manifold 16. This component can improve the assembly efficiency of the cover assembly 10, and the positioning structure 137 can also limit the movement of the manifold 16 relative to the cover 11 to ensure the reliability of the connection between the manifold 16 and the pole post 12 / or pressure ring 14.

[0078] Please see Figure 3 In some embodiments, the positioning structure 137 is strip-shaped and extends along the length of the collector plate 16. This increases the mating area between the positioning structure 137 and the collector plate 16, thereby improving the positioning accuracy of the positioning structure 137 on the collector plate 16.

[0079] It can be understood that the length direction of the collector plate 16 refers to the length direction of the collector plate 16 before bending.

[0080] Please see Figure 3 In some embodiments, the positioning structure 137 has a length dimension L1, and the outer diameter of the lower plastic part 13 is C, satisfying: 0.15C≤L1≤0.3C.

[0081] It is understood that the length L1 of the positioning structure 137 includes, but is not limited to, 0.15C, 0.16C, 0.17C, 0.18C, 0.19C, 0.20C, 0.21C, 0.22C, 0.23C, 0.24C, 0.25C, 0.26C, 0.27C, 0.28C, 0.29C, and 0.3C.

[0082] In this embodiment, by limiting the length L1 of the positioning structure 137, on the one hand, it can ensure that there is sufficient mating area between the positioning structure 137 and the collecting plate 16, so as to ensure the positional stability of the collecting plate 16. On the other hand, it can prevent the length L1 of the positioning structure 137 from being too large and affecting the arrangement of other components.

[0083] Please see Figure 3 In some embodiments, the positioning structure 137 has a width dimension W1 in the direction away from the collector disk 16, satisfying: 0.05C≤L1≤0.15C.

[0084] It is understood that the width dimension W1 of the positioning structure 137 includes, but is not limited to, 0.05C, 0.053C, 0.057C, 0.06C, 0.063C, 0.067C, 0.07C, 0.073C, 0.077C, 0.08C, 0.083C, 0.087C, 0.09C, 0.093C, 0.097C, 0.1C, 0.103C, 0.107C, 0.11C, 0.113C, 0.117C, 0.12C, 0.123C, 0.127C, 0.13C, 0.133C, 0.137C, 0.14C, 0.143C, and 0.15C.

[0085] In this embodiment, by limiting the width dimension W1 of the positioning structure 137, on the one hand, the structural strength of the positioning structure 137 can be guaranteed, so as to ensure the reliability of the connection between the positioning structure 137 and the lower plastic part 13. On the other hand, the width dimension W1 of the positioning structure 137 can be avoided from being too large and affecting the arrangement of other components.

[0086] Please see Figure 3 In some embodiments, there are two positioning structures 137, which are located on both sides of the manifold 16, and the manifold 16 is clearance-fitted with the two positioning structures 137. This improves the ease of assembling the manifold 16 with the lower plastic part 13, thereby improving the assembly efficiency of the cover assembly 10.

[0087] For example, the difference between the gap between the two positioning structures 137 and the width of the collector plate 16 is 0 to 1 mm. For instance, the difference between the gap between the two positioning structures 137 and the width of the collector plate 16 is 0.5 mm, that is, the gap between the collector plate 16 and each positioning structure 137 is 0.25 mm.

[0088] Please see Figure 3 In some embodiments, a groove 138 is provided on the surface of the lower plastic part 13 facing the collector plate 16. A clearance opening 140 is provided on the groove wall of the groove 138. A positioning structure 137 is disposed within the groove 138. The end of the collector plate 16 near the electrode post 12 is located within the groove 138. This allows the lower plastic part 13 and the collector plate 16 to share a portion of their height space, thereby reducing the height dimension of the cover plate assembly 10 and facilitating an increase in the energy density of the battery cell 100.

[0089] It is understandable that the collector plate 16 is in a flat state before bending, with one end connected to the pole post 12 and protruding from the clearance port 140.

[0090] Please see Figure 5 In some embodiments, a core-pressing structure 139 is provided on the surface of the lower plastic part 13 facing away from the cover plate 11. One side of the core-pressing structure 139 is connected to the lower plastic part 13, and the other side is configured to contact the electrode assembly 22 of the battery cell 100. In this way, the core-pressing structure 139 can contact the electrode assembly 22 to fix and press the electrode assembly 22 during battery assembly, ensuring the stability of the electrode assembly 22.

[0091] In addition, after the battery cell 100 is assembled, it can contact the electrode assembly 22 through the core pressing structure 139 to limit the electrode assembly 22 in the axial direction of the battery cell 100, so as to prevent the electrode assembly 22 from shaking relative to the cover plate 11, thereby improving the reliability of the connection between the electrode assembly 22 and other components, which helps to improve the reliability of the battery cell 100.

[0092] The width of the end of the manifold 16 connected to the electrode post 12 is 40%-60% of the outer diameter of the plastic surface of the cover plate 11 facing downwards. This avoids the manifold 16 affecting the contact between the core structure 139 and the electrode assembly 22.

[0093] Please see Figure 5 In some embodiments, the core structure 139 includes a first rib 131 and a second rib 132, both connected to the lower plastic part 13. The first rib 131 extends circumferentially along the cover plate 11. The second rib 132 extends radially along the cover plate 11, and one end of the second rib 132 facing the axis of the cover plate 11 is connected to the first rib 131. This simplifies the structure of the core structure 139 while allowing it to have a larger contact area with the electrode assembly 22, thereby improving the reliability of the lower plastic part 13 in positioning the electrode assembly 22.

[0094] For example, the distance between the inner and outer peripheral surfaces of the first rib 131 is 1.5 mm.

[0095] Please see Figure 5 In some embodiments, the core structure 139 includes a third rib 133, which is disposed at the edge of the lower plastic part 13 and extends circumferentially along the lower plastic part 13. In this way, the circumference of the electrode assembly 22 can be matched with the core structure 139, thereby improving the uniformity of force on the electrode assembly 22.

[0096] It is understood that a groove 138 is provided on the surface of the lower plastic part 13 away from the cover plate 11, and the lower plastic part 13 defines the edge of the groove 138 as a third rib 133.

[0097] For example, the distance between the inner and outer peripheral surfaces of the third rib 133 is 1 mm.

[0098] For example, the outer diameter of the first rib 131 is 3 / 4 of the outer diameter of the third rib 133.

[0099] It can be understood that the second rib 132 is distributed between the first rib 131 and the third rib 133. The number of second ribs 132 is 3 to 6, and the interval angle of the second ribs 132 along the circumference of the pole post 12 is 120° to 60°.

[0100] Please see Figure 5 In some embodiments, there are multiple core structures 139. These multiple core structures 139 are arranged sequentially along the circumference of the cover plate 11. This increases the contact area between the lower plastic part 13 and the electrode assembly 22, thereby improving the stress state of the electrode assembly 22.

[0101] Among them, multiple core structures 139 can be arranged at intervals along the circumference, or some core structures 139 can be arranged at intervals along the circumference, and the first ribs 131 of some core structures 139 are connected to each other.

[0102] Please see Figure 5 In some embodiments, a groove 138 is provided on the surface of the lower plastic part 13 facing the collector plate 16. The core structure 139 is disposed in the groove 138. In this way, while ensuring that the core structure 139 has greater elasticity to improve the reliability of the lower plastic part 13 abutting against the electrode assembly 22, the height of the cover plate assembly 10 can also be reduced, which is beneficial to improving the reliability of the cell 100.

[0103] In some embodiments, the lower plastic part 13 is injection molded to the cover plate 11. This improves the tightness of the connection between the lower plastic part 13 and the cover plate 11, thereby enhancing the seal between them and effectively preventing electrolyte flow between them. This, in turn, improves the smoothness and efficiency of electrode fluid injection. Furthermore, it reduces assembly steps, simplifying the manufacturing process of the cover plate assembly 10 and thus improving its molding efficiency and economy.

[0104] Specifically, the metal parts such as the pressure ring 14, cover plate 11, and pole post 12 are first stamped and formed, and then these metal parts are placed into the injection mold, forming a space between the cover plate 11 and the inner wall of the injection mold to form the lower plastic part 13. Then, the injection mold is injected, and after the injection material is cured, the lower plastic part 13 is formed and integrated with the cover plate 11.

[0105] The sealing ring 15 can be manufactured separately from the top cover of the cover plate 11, or it can be formed by placing the cover plate 11 and the pole post 12 in an injection mold, forming an annular space between the cover plate 11 and the pole post 12 to form the sealing ring 15, and then molding the sealing ring 15 through an injection molding process.

[0106] In some embodiments, the outer diameter of the lower plastic part 13 is smaller than the outer diameter of the surface of the cover plate 11 near the lower plastic part 13. Thus, when the cover plate assembly 10 is fitted with the housing 21, the lower plastic part 13 can be smoothly installed into the housing 21, thereby improving the manufacturing efficiency of the battery cell 100.

[0107] For example, the outer diameter of the surface of the cover plate 11 facing the lower plastic is in the range of 12mm to 100mm, and the outer diameter of the lower plastic is 0.1mm smaller than the outer diameter of the surface of the cover plate 11 facing the lower plastic.

[0108] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A cover plate assembly (10), characterized in that, include: Cover plate (11); The pole post (12) is inserted through the cover plate (11); The lower plastic part (13) is disposed on one side of the cover plate (11); and A pressure ring (14) is sleeved on one end of the pole post (12) and is located on the same side of the cover plate (11) as the lower plastic part (13); Along the radial direction of the pole post (12), the lower plastic part (13) is inserted into the pressure ring (14).

2. The cover plate assembly (10) according to claim 1, characterized in that, A concave structure (141) is provided on the surface of the pressure ring (14) near the lower plastic part (13), and a convex structure (134) is provided on the surface of the lower plastic part (13) near the pressure ring (14). The convex structure (134) is inserted into the concave structure (141) and fits against the inner wall of the concave structure (141).

3. The cover plate assembly (10) according to claim 2, characterized in that, The concave structure (141) is a through groove that extends along the axis of the pole post (12). The convex structure (134) is a column. One end of the column is connected to the lower plastic part (13). The side of the column closest to the axis of the pole post (12) is inserted into the through groove and fits against the inner wall of the through groove.

4. The cover plate assembly (10) according to claim 3, characterized in that, The convex structure (134) is integrally formed with the lower plastic part (13); and / or, the column is a cylinder and the cross-section of the through groove is semi-circular.

5. The cover plate assembly (10) according to any one of claims 1-4, characterized in that, The lower plastic part (13) is provided with a liquid passage hole (135), and the cover plate (11) is provided with a liquid injection hole (111). The liquid passage hole (135) and the liquid injection hole (111) are arranged opposite to each other.

6. The cover plate assembly (10) according to claim 5, characterized in that, The port of the liquid passage (135) facing away from the cover plate (11) is the liquid outlet port (1351), and the end face of the lower plastic part (13) facing away from the cover plate (11) is the contact end face (136). The liquid outlet port (1351) is located on the side of the contact end face (136) close to the cover plate (11).

7. The cover plate assembly (10) according to claim 6, characterized in that, Along the axial direction of the pole post (12), the total height dimension of the lower plastic part (13) is H1, and the length dimension of the liquid passage hole (135) is H2, satisfying: 0.3H1≤H2≤0.7H1; And / or, a groove (138) is provided on the side of the lower plastic part (13) away from the cover plate (11), and the liquid outlet port (1351) is provided at the bottom of the groove (138).

8. The cover plate assembly (10) according to any one of claims 1-4, characterized in that, The cover plate assembly (10) further includes a manifold (16) located on the side of the lower plastic part (13) away from the cover plate (11), and the manifold (16) is connected to the pole post (12) and / or the pressure ring (14).

9. The cover plate assembly (10) according to claim 8, characterized in that, A positioning structure (137) is provided on the surface of the lower plastic part (13) facing the manifold (16), and the surface of the positioning structure (137) facing the axis of the cover assembly (10) is in contact with the manifold (16).

10. The cover plate assembly (10) according to claim 9, characterized in that, The positioning structure (137) is strip-shaped and extends along the length of the collecting disk (16).

11. The cover plate assembly (10) according to claim 10, characterized in that, The positioning structure (137) has a length dimension L1, and the outer diameter of the lower plastic part (13) is C, satisfying: 0.15C≤L1≤0.3C; And / or, the positioning structure (137) has a width dimension W1 in the direction away from the collector disk (16) such that: 0.05C≤L1≤0.15C.

12. The cover plate assembly (10) according to claim 9, characterized in that, There are two positioning structures (137), which are located on both sides of the collecting plate (16) and are in clearance fit with the two positioning structures (137). And / or, a groove (138) is provided on the surface of the lower plastic part (13) facing the collector plate (16), an avoidance opening (140) is provided on the groove wall of the groove (138), the positioning structure (137) is provided in the groove (138), and one end of the collector plate (16) near the pole post (12) is located in the groove (138).

13. The cover plate assembly (10) according to any one of claims 1-4, characterized in that, A core structure (139) is provided on the surface of the lower plastic part (13) away from the cover plate (11). One side of the core structure (139) is connected to the lower plastic part (13), and the other side is configured to contact the electrode assembly (22) of the cell (100).

14. The cover plate assembly (10) according to claim 13, characterized in that, The core structure (139) includes a first rib (131) and a second rib (132) both connected to the lower plastic part (13). The first rib (131) extends circumferentially along the cover plate (11), and the second rib (132) extends radially along the cover plate (11). The end of the second rib (132) facing the axis of the cover plate (11) is connected to the first rib (131). And / or, the core structure (139) includes a third rib (133) disposed at the edge of the lower plastic part (13) and extending circumferentially along the lower plastic part (13).

15. The cover plate assembly (10) according to any one of claims 1-4, characterized in that, The lower plastic part (13) is injection molded to the cover plate (11); and / or, the outer diameter of the lower plastic part (13) is smaller than the outer diameter of the surface of the cover plate (11) near the lower plastic part (13).

16. A battery cell (100), characterized in that, include: Shell (21); Electrode assembly (22) is disposed within the housing (21); as well as The cover plate assembly (10) according to any one of claims 1-15, wherein the cover plate (11) covers the housing (21) and the electrode assembly (22) is connected to the electrode post (12).

17. A battery pack (1000), characterized in that, Includes the battery cell (100) as described in claim 16, wherein there are multiple battery cells (100) and the multiple battery cells (100) are electrically connected.

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