Secondary battery and cover assembly thereof

Abstract

The embodiment of the present application discloses a secondary battery and its cover plate assembly, the cover plate assembly includes a cover body, a seal, a pole and a connector. The cover body has a through-going mounting hole; the seal is located on one side of the cover body along the axial direction of the mounting hole, and is arranged around the axis of the mounting hole in a full circle outside the mounting hole, the seal is made of an insulating material and has elasticity; the pole is covered on one side of the seal and is arranged in the mounting hole, so that the seal is clamped between the pole and the cover body along the axial direction of the mounting hole; the connector is made of an insulating material, and the connector is fixedly connected to the cover body and the pole, respectively, so that the pole presses the seal along the axial direction of the mounting hole, thereby sealing the pole and the cover body at the mounting hole. In the embodiment of the present application, the cover plate assembly reduces the number of parts, thereby reducing costs.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a secondary battery and a cover plate assembly thereof. Background Art

[0002] Secondary batteries are widely used as power batteries in electric vehicles and energy storage fields. The cover assembly of the secondary battery is welded to the aluminum shell of the secondary battery to form a housing cavity isolated from the outside world. The current inside the secondary battery is transmitted to the outside through the pole in the cover assembly.

[0003] The traditional cover assembly is mainly composed of a bare aluminum sheet, a riveted block, a pole, an upper plastic, a lower plastic, and a sealing ring. The traditional cover assembly has many parts, resulting in a high cost of the cover assembly. Summary of the invention

[0004] The embodiments of the present application provide a secondary battery and a cover plate assembly thereof, which reduce the number of components of the cover plate assembly and reduce the cost of the cover plate assembly.

[0005] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0006] On the one hand, a cover plate assembly of a secondary battery is provided, comprising a cover body, a sealing member, a pole and a connecting member. The cover body has a through-going mounting hole; the sealing member is located on one side of the cover body along the axial direction of the mounting hole, and is arranged around the axis of the mounting hole in a full circle outside the mounting hole, and the sealing member is made of an insulating material and has elasticity; the pole is covered on one side of the sealing member in the mounting hole, and the sealing member is clamped between the pole and the cover body along the axial direction of the mounting hole; the connecting member is made of an insulating material, and the connecting member is fixedly connected to the cover body and the pole, respectively, so that the pole presses the sealing member along the axial direction of the mounting hole, thereby sealing the pole and the cover body at the mounting hole.

[0007] In addition to or as an alternative to one or more features disclosed above, the cover body has a mounting groove, the mounting groove is located on the surface of the cover body facing the seal, the mounting hole is arranged at the bottom of the mounting groove, and the seal is accommodated in the mounting groove.

[0008] In addition to or as an alternative to one or more of the features disclosed above, along the axial direction of the mounting hole, the pole protrudes from the cover body and the connecting piece respectively.

[0009] In addition to or as an alternative to one or more of the features disclosed above, the height of the pole protruding from the cover body is less than or equal to 2.5 mm.

[0010] In addition to or as an alternative to one or more features disclosed above, the connector is arranged around the axis of the mounting hole in a complete circle outside the pole, and a seam arranged around the axis of the mounting hole is formed between the connector and the pole, and the sealing member covers the seam.

[0011] In addition to or as an alternative to one or more of the features disclosed above, the joint extends non-linearly in the axial direction of the mounting hole.

[0012] In addition to or as an alternative to one or more features disclosed above, the seam extends a first distance toward the cover body along the axial direction of the mounting hole, then extends a second distance radially inwardly along the mounting hole, and then extends a third distance toward the cover body along the axial direction of the mounting hole.

[0013] In addition to one or more of the features disclosed above, or as an alternative, the connector and the pole together form a receiving groove, the opening of the receiving groove faces the cover body and is arranged in a full circle around the axis of the mounting hole, a seam is formed at the bottom of the receiving groove, and a sealing member is accommodated in the receiving groove.

[0014] In addition to one or more of the features disclosed above, or as an alternative, the connecting piece is welded to the cover body and the pole respectively; or, the connecting piece is threadedly connected to the cover body and the pole respectively; or, the connecting piece is welded to one of the cover body and the pole and threadedly connected to the other of the cover body and the pole.

[0015] In addition to one or more of the features disclosed above, or as an alternative, the cover body has a mounting groove, the mounting groove is located on the surface of the cover body facing the seal, the mounting hole is arranged at the bottom of the mounting groove, the connecting piece is arranged in a full circle around the axis of the mounting hole and is embedded in the mounting groove, the connecting piece and the cover body are welded and connected at the edge of the groove of the mounting groove, and at the edge of the groove of the mounting groove, the connecting piece is flush with the cover body.

[0016] In addition to one or more of the features disclosed above, or as an alternative, the connecting piece is arranged in a complete circle around the axis of the mounting hole outside the pole, and a seam arranged around the axis of the mounting hole is formed between the connecting piece and the pole. The connecting piece and the pole are welded to each other at one end of the seam facing away from the cover body, and at the end of the seam facing away from the cover body, the connecting piece is flush with the pole.

[0017] In addition to or as an alternative to one or more of the features disclosed above, the cover assembly further comprises an insulating member. The first portion of the insulating member is located on the other side of the cover body along the axial direction of the mounting hole, the second portion of the insulating member and the sealing member are located on the same side of the cover body, the third portion of the insulating member is located in the mounting hole and respectively connects the first portion and the second portion, the second portion is sandwiched between the sealing member and the cover body in the axial direction of the mounting hole, and the pole presses the second portion against the cover body through the sealing member in the axial direction of the mounting hole.

[0018] In addition to or as an alternative to one or more of the features disclosed above, an edge of the mounting hole facing the sealing member has a notch to form a step shape, and the second part is accommodated in the notch.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the second portion is arranged in a complete circle around the axis of the mounting hole.

[0020] In addition to one or more of the features disclosed above, or as an alternative, the compression rate of the seal along the axial direction of the mounting hole is greater than or equal to 20% and less than or equal to 75%; or the compression amount of the seal along the axial direction of the mounting hole is greater than or equal to 0.2mm and less than or equal to 2mm.

[0021] On the other hand, a secondary battery is provided, the secondary battery comprising a shell, a cover plate assembly and an electrode assembly. One side of the shell has an opening; the cover plate assembly covers the opening of the shell and is surrounded by the shell to form a receiving cavity; the electrode assembly is received in the receiving cavity. The cover plate assembly is any of the above-mentioned cover plate assemblies.

[0022] One of the above technical solutions has the following advantages or beneficial effects:

[0023] The pole is covered in the mounting hole on one side of the seal, and the seal is clamped between the pole and the cover body along the axial direction of the mounting hole. The connector is made of an insulating material, and the connector is fixedly connected to the cover body and the pole, respectively, so that the pole presses the seal along the axial direction of the mounting hole, thereby sealing the pole and the cover body at the mounting hole. Compared with the prior art, the cover assembly reduces the number of parts and components, thereby reducing costs. In addition, since the number of parts and components is reduced, the weight of the cover assembly can also be reduced and the assembly process can be reduced. In the case where the cover body has a mounting groove, the seal is accommodated in the mounting groove, which is conducive to reducing the size of the cover assembly in the axial direction of the mounting hole, thereby improving the volume energy density of the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0025] Figure 1 It is a three-dimensional structural schematic diagram of a cover plate assembly in the related art;

[0026] Figure 2 yes Figure 1 a side view of the cover assembly shown;

[0027] Figure 3 yes Figure 1 a bottom view of the cover assembly shown;

[0028] Figure 4 yes Figure 1 A partial cross-sectional view of the cover plate assembly at the pole;

[0029] Figure 5 is a three-dimensional exploded view of an embodiment of a secondary battery of the present application;

[0030] Figure 6 is a schematic diagram of the three-dimensional structure of an embodiment of a cover plate assembly of the present application;

[0031] Figure 7 is a three-dimensional exploded view of an embodiment of a cover plate assembly of the present application;

[0032] Figure 8 is a top view of an embodiment of a cover plate assembly of the present application;

[0033] Fig. 9 is a cross-sectional view of an embodiment of the cover plate assembly of the present application in an assembled state;

[0034] Fig.10 is a cross-sectional view of an embodiment of the cover plate assembly of the present application in an exploded state;

[0035] Fig.11 is a cross-sectional view of a connector, a pole, and a seal in an exploded state in an embodiment of a cover plate assembly of the present application;

[0036] Fig.12 It is a cross-sectional view of an embodiment of a cover plate assembly of the present application.

[0037] Explanation of the reference numerals: 201-cover; 203-pole; 205-rivet; 207-lower plastic; 209-upper plastic; 211-seal; 213-first assembly hole; 215-second assembly hole; 100-secondary battery; 101-shell; 103-cover assembly; 105-electrode assembly; 107-opening; 109-accommodating chamber; 111-cover; 113-pole; 115-explosion-proof valve; 117-liquid injection hole; 119-insulating member; 121-seal; 123-connector; 125-mounting hole; 127-mounting groove; 129-seam; 131-accommodating groove; 133-slot edge; 135-first part; 137-second part; 139-third part; 141-notch; 143-chamfer; L1-axis line. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and beneficial effects of this application more clear, the following further describes this application in detail in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining this application, not for limiting this application.

[0039] A secondary battery is a battery that can be recharged to activate the active materials after being discharged and continue to be used.

[0040] Figure 1 It is a schematic diagram of the three-dimensional structure of the cover plate assembly in the related technology. Figure 2 yes Figure 1 A side view of the cover plate assembly is shown. Figure 3 yes Figure 1 Bottom view of the cover assembly shown. Figure 4 yes Figure 1 The illustrated is a partial cross-sectional view of the cover plate assembly at the pole 203 .

[0041] In the related art, the cover plate assembly includes a cover body 201 , a pole 203 , a rivet 205 , a seal 211 , an upper plastic 209 and a lower plastic 207 .

[0042] The cover body 201 has a first assembly hole 213 extending therethrough. The first assembly hole 213 has an axis L0.

[0043] The lower plastic 207 has a penetrating second assembly hole 215 . The second assembly hole 215 is disposed opposite to the first assembly hole 213 .

[0044] The pole 203 is respectively disposed in the first assembly hole 213 and the second assembly hole 215 , and presses the lower plastic 207 against the cover 201 along the axis L0 , thereby fixing the lower plastic 207 to the cover 201 .

[0045] The seal 211 is used to seal the pole 203 and the cover 201. Specifically, the seal 211 is sleeved outside the pole 203, and is clamped between the pole 203 and the cover 201 along the radial direction of the first assembly hole 213, and is clamped between the lower plastic 207 and the cover 201 along the axial direction of the first assembly hole 213.

[0046] The rivet 205 and the lower plastic 207 are respectively disposed on two opposite sides of the cover 201. The rivet 205 is riveted to the pole 203.

[0047] The upper plastic 209 is disposed around the pole 203 and connects the rivet 205 to the cover 201. The upper plastic 209 can be formed between the rivet 205 and the cover 201 by injection molding.

[0048] When assembling the cover assembly, the lower plastic 207 , the seal 211 , the pole 203 and the rivet 205 may be assembled to the cover body 201 , and then the whole assembly may be put into an injection molding machine, and the upper plastic 209 may be molded in the injection molding machine.

[0049] In the related art, the cover plate assembly has a large number of parts and components, a large weight, and many assembly steps, which results in a high cost of the cover plate assembly and is not conducive to cost reduction and weight reduction of secondary batteries.

[0050] In the related art, the height H1 of the pole 203 in the cover plate assembly (the distance from the upper surface of the cover body 201 to the upper surface of the rivet 205) is relatively high, generally 3.2 mm, which is not conducive to improving the volume energy density of the secondary battery.

[0051] In the related art, the upper plastic 209 is injection molded, resulting in low structural strength of the cover assembly and poor rigidity at the upper plastic 209. Under a large force, the upper plastic 209 may even crack. In addition, when molding the upper plastic 209, once the injection molding fails, the electrolyte of the secondary battery may leak, causing safety hazards and low reliability.

[0052] The secondary battery and the cover plate assembly embodiment of the present application are used to solve the problems in the above-mentioned related technologies.

[0053] Figure 5 It is a three-dimensional exploded view of an embodiment of a secondary battery 100 of the present application.

[0054] The secondary battery 100 includes a housing 101 , a cap plate assembly 103 , and an electrode assembly 105 .

[0055] One side of the housing 101 has an opening 107. Specifically, the housing 101 is substantially in a rectangular box shape and has an opening 107 at one end of the Z axis.

[0056] The cover plate assembly 103 covers the opening 107 of the housing 101 and is surrounded by the housing 101 to form a receiving chamber 109. The receiving chamber 109 also receives electrolyte.

[0057] The electrode assembly 105 is accommodated in the accommodating cavity 109. The electrode assembly 105 includes a positive electrode sheet (not shown), a negative electrode sheet (not shown), and a separator (not shown). During the charge and discharge process of the battery, active ions are embedded and removed back and forth between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet to play an isolation role. The electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet. In some embodiments, the electrode assembly 105 is wound by a positive electrode sheet, a negative electrode sheet, and a separator. In other embodiments, the electrode assembly 105 is stacked by a positive electrode sheet, a negative electrode sheet, and a separator.

[0058] The secondary battery 100 is not limited to the square battery shown in the figure. The present application does not limit the specific structure of the secondary battery 100, and the improvement of the present application mainly lies in the cover plate assembly 103.

[0059] Figure 6 It is a schematic diagram of the three-dimensional structure of an embodiment of the cover assembly 103 of the present application. Figure 7 It is a three-dimensional exploded view of an embodiment of the cover assembly 103 of the present application. Figure 8 It is a top view of an embodiment of the cover assembly 103 of the present application.

[0060] In some embodiments, the cover plate assembly 103 includes a cover body 111 , a seal 121 , a pole 113 , a connector 123 , and an insulating member 119 .

[0061] The cover 111 is used to cover the opening 107 of the shell 101 of the secondary battery 100, so as to surround the shell 101 to form a receiving cavity 109. In some embodiments, the cover 111 is generally flat. The material of the cover 111 is aluminum or aluminum alloy. The cover 111 and the shell 101 are laser welded.

[0062] In some embodiments, the cover 111 has a liquid injection hole 117 to inject electrolyte into the accommodating cavity 109 through the liquid injection hole 117 .

[0063] In some embodiments, the cover 111 has an explosion-proof valve 115 to release the high-pressure gas in the accommodating chamber 109 through the explosion-proof valve 115 .

[0064] The cover body 111 has a mounting hole 125 extending therethrough. The mounting hole 125 has an axis L1. The axis L1 extends in the inner and outer directions of the accommodating chamber 109. The pole 113 is installed at the mounting hole 125. A portion of the pole 113 is located in the accommodating chamber 109 and is electrically connected to the electrode assembly 105. Another portion of the pole 113 is located outside the accommodating chamber 109 for outputting current. In some embodiments, the mounting hole 125 is a circular hole. In other embodiments, the mounting hole 125 is a square hole, an elliptical hole, or a hole of other irregular shape. The shape of the mounting hole 125 matches the shape of the pole 113. The specific shape of the mounting hole 125 is not limited.

[0065] In some embodiments, as shown in the figure, the number of poles 113 in the cover plate assembly 103 is two, one pole 113 is the positive pole of the secondary battery 100, and the other pole 113 is the negative pole of the secondary battery 100. Correspondingly, the cover body 111 has two mounting holes 125, and the poles 113 correspond to the mounting holes 125 one by one. Each pole 113 is installed at the corresponding mounting hole 125.

[0066] In some embodiments, the number of poles 113 in the cap plate assembly 103 is one, and one pole 113 is the positive electrode or the negative electrode of the secondary battery 100. For example, the secondary battery 100 has two cap plate assemblies 103, wherein the pole 113 in one cap plate assembly 103 is the positive electrode of the secondary battery 100, and the pole 113 in the other cap plate assembly 103 is the negative electrode of the secondary battery 100.

[0067] The sealing member 121 is disposed at the mounting hole 125 and is used to seal the connection between the pole 113 and the cover 111 .

[0068] The sealing member 121 is located on one side of the cover body 111 along the axial direction of the mounting hole 125. Specifically, the sealing member 121 is located on the outer side of the cover body 111, that is, on the side away from the housing 101.

[0069] The seal 121 is disposed around the axis L1 of the mounting hole 125 and is arranged outside the mounting hole 125 in a full circle. In some embodiments, the mounting hole 125 is a circular hole, and the seal 121 is coaxially disposed with the mounting hole 125. In some embodiments, the mounting hole 125 is a square hole, and the seal 121 is in a square frame shape, and along the circumference of the mounting hole 125, the distance between the seal 121 and the edge of the mounting hole 125 is substantially equal.

[0070] The sealing member 121 is made of an insulating material and has elasticity. In some embodiments, the sealing member 121 is made of a rubber material.

[0071] In some embodiments, the compression rate of the seal 121 along the axial direction of the mounting hole 125 is greater than or equal to 20% and less than or equal to 75%. The axial compression rate refers to the ratio of the axial compression amount of the seal 121 to the axial size of the seal 121 in an uncompressed state. For example, the axial compression rate is 20%, 25%, 45%, 65% or 75%.

[0072] In some embodiments, the compression amount of the sealing member 121 along the axial direction of the mounting hole 125 is greater than or equal to 0.2 mm and less than or equal to 2 mm. For example, the axial compression amount is 0.2 mm, 0.5 mm, 1 mm, 1.5 mm or 2 mm.

[0073] Fig. 9 It is a cross-sectional view of the cover plate assembly 103 embodiment of the present application in an assembled state. Fig.10 It is a cross-sectional view of the cover plate assembly 103 embodiment of the present application in a disassembled state.

[0074] The pole 113 is covered on the mounting hole 125 on one side of the seal 121, and the seal 121 is sandwiched between the pole 113 and the cover 111 along the axial direction of the mounting hole 125. Specifically, with the axial direction of the mounting hole 125 as the projection direction, the projection of the mounting hole 125 is located within the projection of the pole 113. The pole 113 can be mounted on the edge of the mounting hole 125. In some embodiments, as shown in the figure, a portion of the central area of ​​the pole 113 is accommodated in the mounting hole 125. On the one hand, the thickness of the pole 113 in the axial direction of the mounting hole 125 is increased to enhance the strength of the pole 113. On the other hand, the sealing effect of the pole 113 and the cover 111 in the mounting hole 125 can be improved. The surface of the pole 113 facing away from the cover 111 is used to be electrically connected to the busbar to supply power to the outside. The surface of the pole 113 facing the accommodating cavity 109 through the mounting hole 125 is used to be electrically connected to the electrode assembly 105.

[0075] In some embodiments, the cover body 111 has a mounting groove 127, and the mounting groove 127 is located on the surface of the cover body 111 facing the seal 121. Among them, the mounting hole 125 is arranged at the bottom of the mounting groove 127, and the seal 121 is accommodated in the mounting groove 127. In some embodiments, with the axial direction of the mounting hole 125 as the projection direction, the projection of the mounting groove 127 is circular, and the projection of the seal 121 is annular. The outer diameter of the mounting groove 127 is greater than the outer diameter of the seal 121. In the axial direction of the mounting hole 125, the depth of the mounting groove 127 is greater than the height of the seal 121. The seal 121 is completely accommodated in the mounting groove 127. Such a configuration is conducive to reducing the size of the cover plate assembly 103 in the axial direction of the mounting hole 125, thereby improving the volume energy density of the secondary battery.

[0076] In some embodiments, the pole 113 protrudes from the cover 111 and the connector 123 along the axial direction of the mounting hole 125. This arrangement makes it easier for the pole 113 to be electrically connected to external parts. In the application scenario where the pole 113 is welded to the bus bar, the pole 113 protrudes from the cover 111 and the connector 123, respectively, so that the bus bar is not interfered.

[0077] In some embodiments, the height H2 of the pole 113 protruding from the cover 111 is less than or equal to 2.5 mm. For example, the height H2 of the pole 113 protruding from the cover 111 is 2 mm or 1.5 mm.

[0078] The connector 123 is used to fix the pole 113 to the cover 111. The connector 123 is made of an insulating material. In some embodiments, the connector 123 is made of a ceramic material. The connector 123 is fixedly connected to the cover 111 and the pole 113, respectively, so that the pole 113 presses the sealing member 121 along the axial direction of the mounting hole 125, thereby sealing the pole 113 and the cover 111 at the mounting hole 125.

[0079] In some embodiments, the connector 123 is arranged around the axis L1 of the mounting hole 125 and is arranged outside the pole 113 in a complete circle. That is, the connector 123 is a complete ring. Such an arrangement enables the connector 123 to be fixedly connected to all the edges of the pole 113 in the circumferential direction, thereby enabling the pole 113 to apply a uniform pressure to the seal 121 in the circumferential direction, thereby improving the sealing effect of the seal 121.

[0080] When the connector 123 is disposed around the axis L1 of the mounting hole 125 and outside the pole 113 in a full circle, in some embodiments, a joint 129 disposed around the axis L1 of the mounting hole 125 is formed between the connector 123 and the pole 113, and the sealing member 121 covers the joint 129. This arrangement improves the sealing effect at the joint 129.

[0081] In some embodiments, the joint 129 extends nonlinearly in the axial direction of the mounting hole 125. Specifically, the joint 129 extends a first distance along the axial direction of the mounting hole 125 toward the cover body 111, then extends a second distance inwardly along the radial direction of the mounting hole 125, and then extends a third distance toward the cover body 111 along the axial direction of the mounting hole 125. In this way, a labyrinth seal structure is formed between the connector 123 and the pole 113, further improving the sealing effect at the joint 129.

[0082] Please also read Fig.11 . Fig.11 It is a cross-sectional view of the connector 123, the pole 113 and the seal 121 in the exploded state in the embodiment of the cover plate assembly 103 of the present application.

[0083] In some embodiments, the connector 123 and the pole 113 jointly form a receiving groove 131, the opening of the receiving groove 131 faces the cover 111, and is arranged in a circle around the axis L1 of the mounting hole 125, the joint 129 is formed at the bottom of the receiving groove 131, and the sealing member 121 is accommodated in the receiving groove 131. When assembling the cover assembly 103, the connector 123 and the pole 113 can be fixedly connected to form the receiving groove 131, and then the sealing member 121 can be plugged into the receiving groove 131, and then the pole 113 is covered in the mounting hole 125, and then the connector 123 is fixedly connected to the cover 111. Such a configuration can improve the position accuracy of the sealing member 121, and at the same time, a labyrinth seal structure is formed between the connector 123, the pole 113 and the cover 111 in the radial direction of the mounting hole 125.

[0084] The connection member 123 is fixedly connected to the cover 111 and the pole 113 respectively in the following manner:

[0085] In some embodiments, the connector 123 is respectively welded to the cover 111 and the pole 113. Specifically, in some embodiments, the connector 123 is made of ceramic material, and the connector 123 can be respectively welded to the cover 111 and the pole 113 by a brazing process. To improve the welding quality, in some embodiments, a metal layer is preformed on the surface to be welded of the connector 123, or a metal layer is preformed on the surface to be welded of the cover 111 and the surface to be welded of the pole 113.

[0086] In the case where the cover 111 has a mounting groove 127, in some embodiments, the connector 123 is embedded in the mounting groove 127 to reduce the height of the connector 123 protruding from the cover 111. The connector 123 is welded to the cover 111 at the notch edge 133 of the mounting groove 127. Fig.10 As shown, since the connecting member 123 protrudes at the groove edge 133 of the mounting groove 127, the welding equipment (laser welding head) or the cover plate assembly 103 needs to be set at an angle.

[0087] Please also read Fig.12 . Fig.12 It is a cross-sectional view of an embodiment of the cover plate assembly 103 of the present application.

[0088] In some embodiments, the connector 123 is welded to the cover 111 at the notch edge 133 of the mounting groove 127, and the connector 123 is flush with the cover 111 at the notch edge 133 of the mounting groove 127. With this arrangement, during the welding operation, the welding equipment (laser welding head) or the cover assembly 103 does not need to be tilted, which can improve the welding efficiency.

[0089] When the connector 123 is arranged around the axis L1 of the mounting hole 125 and outside the pole 113 in a full circle, and when the connector 123 and the pole 113 form a joint 129 arranged around the axis L1 of the mounting hole 125, the connector 123 and the pole 113 are welded at the end of the joint 129 facing away from the cover 111, and at the end of the joint 129 facing away from the cover 111 (at the Q2 position), the connector 123 is flush with the pole 113. With such an arrangement, during the welding operation, the welding equipment (laser welding head) or the cover plate assembly 103 does not need to be tilted, which can improve the welding efficiency.

[0090] In some embodiments, the connector 123 is arranged around the axis L1 of the mounting hole 125 and is arranged outside the pole 113 in a full circle, and is embedded in the mounting groove 127. The connector 123 and the cover body 111 are welded and connected in a full circle around the axis L1 at the Q1 position. The connector 123 and the pole 113 are welded and connected in a full circle around the axis L1 at the Q2 position and the Q3 position. In this way, the sealing effect between the pole 113 and the cover body 111 at the mounting hole 125 can be further improved. Specifically, when assembling the cover plate assembly 103, the connector 123 is first welded and connected to the pole 113, and then the connector 123 is welded and connected to the cover body 111.

[0091] In some embodiments, the connector 123 is threadedly connected to the cover 111 and the pole 113 , respectively. In some embodiments, the axial direction of the connecting thread of the connector 123 is the axial direction of the mounting hole 125 .

[0092] In some embodiments, the connector 123 is welded to one of the cover 111 and the pole 113 , and is threadedly connected to the other of the cover 111 and the pole 113 .

[0093] For example, the connector 123 is welded to the cover 111 and is threaded to the pole 113. During the assembly of the cover 111 assembly, the connector 123 is first welded to the cover 111, and then the seal 121 is placed, and then the pole 113 is threaded to the connector 123, and the pole 113 is tightened in the axial direction of the mounting hole 125, so that the pole 113 presses against the seal 121.

[0094] The fixing connection method of the connecting member 123 and the cover body 111 or the pole 113 is not limited to welding and threaded connection, and other fixing methods such as bonding may also be used.

[0095] In the embodiment of the present application, the connector 123 is fixedly connected to the cover body 111 and the pole 113 respectively, so that the pole 113 can apply a large pressure to the seal 121 to ensure the sealing effect at the seal 121, and the connector 123 is not easily damaged or failed, which improves the reliability compared with the above-mentioned related technologies.

[0096] The insulating member 119 is used to prevent the electrode assembly 105 from contacting the cover 111 .

[0097] The first portion 135 of the insulating member 119 is located on the other side of the cover 111 along the axial direction of the mounting hole 125, the second portion 137 of the insulating member 119 and the sealing member 121 are located on the same side of the cover 111, and the third portion 139 of the insulating member 119 is located in the mounting hole 125 and respectively connects the first portion 135 and the second portion 137. The second portion 137 is sandwiched between the sealing member 121 and the cover 111 in the axial direction of the mounting hole 125. The pole 113 presses the second portion 137 against the cover 111 along the axial direction of the mounting hole 125 through the sealing member 121.

[0098] When assembling the cover assembly 103, the insulating member 119 is assembled to the cover body 111, and then the insulating member 119 and the pole 113 are assembled. The pole 113 presses the second portion 137 of the insulating member 119 while pressing the insulating member 119, which can improve the fixing effect of the insulating member 119 on the cover body 111.

[0099] In some embodiments, the edge of the mounting hole 125 facing the sealing member 121 has a notch 141, and the second portion 137 is accommodated in the notch 141. Further, in the axial direction of the mounting hole 125, the thickness of the second portion 137 is less than or equal to the depth of the notch 141, so that the second portion 137 does not protrude from the bottom surface of the mounting groove 127. Such a configuration can prevent the second portion 137 from affecting the protruding height of the pole 113.

[0100] In some embodiments, a depth H3 of the notch 141 in the axial direction of the mounting hole 125 is greater than or equal to 0.2 mm.

[0101] In some embodiments, a width G1 of the second portion 137 in the radial direction of the mounting hole 125 is greater than or equal to 0.5 mm.

[0102] In some embodiments, the second portion 137 is arranged in a circle around the axis L1 of the mounting hole 125, and correspondingly, the third portion 139 is arranged in a circle around the axis L1 of the mounting hole 125, and the notch 141 is arranged in a circle around the axis L1 of the mounting hole 125. Such a configuration can increase the area of ​​the insulating member 119 being pressed, and further improve the fixing effect of the insulating member 119.

[0103] In some embodiments, a chamfer 143 is disposed on the outer edge of the second portion 137 , so that it is easier to assemble the insulating member 119 to the cover 111 through the mounting hole 125 .

[0104] In summary, in the embodiment of the present application, the connector fixes the pole to the cover body, and causes the pole to press against the seal along the axial direction of the mounting hole, thereby sealing the pole and the cover body at the mounting hole. Compared with the prior art, the cover assembly reduces the number of parts, thereby reducing costs. In addition, due to the reduction in the number of parts, the weight of the cover assembly can also be reduced and the assembly process can be reduced.

[0105] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the present application. For ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A cover plate assembly for a secondary battery, characterized in that: include: A cover body, wherein the cover body has a penetrating mounting hole; A sealing member, the sealing member is located on one side of the cover body along the axial direction of the mounting hole, and is arranged around the axis of the mounting hole in a full circle outside the mounting hole, the sealing member is made of an insulating material and has elasticity; A pole, wherein the pole is covered on one side of the sealing member and disposed on the mounting hole, and the sealing member is sandwiched between the pole and the cover body along the axial direction of the mounting hole; A connecting piece, the connecting piece is made of an insulating material, and the connecting piece is fixedly connected to the cover body and the pole, respectively, so that the pole presses the sealing piece along the axial direction of the mounting hole, thereby sealing the pole and the cover body at the mounting hole; The connecting member is arranged around the axis of the mounting hole and outside the pole in a complete circle, and a joint arranged around the axis of the mounting hole is formed between the connecting member and the pole, and the sealing member covers the joint; The connecting member and the pole together form a receiving groove, the opening of the receiving groove faces the cover body and is arranged in a full circle around the axis of the mounting hole, the joint is formed at the bottom of the receiving groove, and the sealing member is received in the receiving groove; The connecting piece is respectively connected to the cover body and the pole by welding; or, The connecting piece is respectively connected with the cover body and the pole by threads; or, The connecting piece is welded to one of the cover body and the pole, and is threadedly connected to the other of the cover body and the pole; The cover body has a mounting groove, the mounting groove is located on the surface of the cover body facing the sealing member, the mounting hole is arranged at the bottom of the mounting groove, the connecting member is arranged in a full circle around the axis of the mounting hole and is embedded in the mounting groove, the connecting member and the cover body are welded and connected at the edge of the notch of the mounting groove, and the connecting member is flush with the cover body at the edge of the notch of the mounting groove; and / or, The connecting piece is arranged around the axis of the mounting hole in a complete circle outside the pole, and a seam arranged around the axis of the mounting hole is formed between the connecting piece and the pole. The connecting piece and the pole are welded and connected at one end of the seam facing away from the cover body, and at the end of the seam facing away from the cover body, the connecting piece is flush with the pole.

2. The cover plate assembly according to claim 1, characterized in that: The cover body has a mounting groove, the mounting groove is located on the surface of the cover body facing the sealing member, the mounting hole is arranged at the bottom of the mounting groove, and the sealing member is accommodated in the mounting groove.

3. The cover plate assembly according to claim 2, characterized in that: Along the axial direction of the mounting hole, the poles protrude from the cover body and the connecting member respectively.

4. The cover plate assembly according to claim 3, characterized in that: The height of the pole protruding from the cover body is less than or equal to 2.5 mm.

5. The cover plate assembly according to claim 1, characterized in that: The seam extends nonlinearly in the axial direction of the mounting hole, or the seam extends a first distance in the axial direction of the mounting hole toward the cover body, then extends a second distance radially inwardly along the mounting hole, and then extends a third distance in the axial direction of the mounting hole toward the cover body.

6. The cover plate assembly according to claim 1, characterized in that: Also includes: An insulating member, wherein the first portion of the insulating member is located on the other side of the cover body along the axial direction of the mounting hole, the second portion of the insulating member and the sealing member are located on the same side of the cover body, the third portion of the insulating member is located in the mounting hole and respectively connects the first portion and the second portion, the second portion is clamped between the sealing member and the cover body in the axial direction of the mounting hole, and the pole presses the second portion against the cover body through the sealing member along the axial direction of the mounting hole.

7. The cover plate assembly according to claim 6, characterized in that: The edge of the mounting hole facing the sealing member has a notch, and the second part is accommodated in the notch.

8. The cover plate assembly according to claim 6, characterized in that: The second part is arranged in a complete circle around the axis of the mounting hole.

9. The cover plate assembly according to claim 1, characterized in that: The compression rate of the sealing member along the axial direction of the mounting hole is greater than or equal to 20% and less than or equal to 75%; or The compression amount of the sealing member along the axial direction of the mounting hole is greater than or equal to 0.2 mm and less than or equal to 2 mm.

10. A secondary battery, characterized in that: include: A housing, one side of which has an opening; A cover plate assembly, the cover plate assembly is arranged to cover the opening of the shell and is surrounded by the shell to form a receiving cavity; An electrode assembly, wherein the electrode assembly is accommodated in the accommodation cavity; Wherein, the cover plate assembly is the cover plate assembly according to any one of claims 1 to 9.

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