Top cover assembly, single battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and provides a top cover assembly, a single battery cell and a battery pack. The top cover assembly comprises a cover plate, a pole and a first sealing piece. The cover plate is provided with a mounting hole. The pole penetrates through the mounting hole. A channel for communicating the inside and the outside of the cover plate is formed in the pole. And the channel is configured to allow the tabs to pass through. The first sealing element is arranged in the mounting hole, and the first sealing element is sleeved on the pole; therefore, the tabs do not need to be bent in the shell, a height space reserved for bending the tabs in the shell is omitted, the height of the electrode assembly can be increased, and the volume energy density of the battery is increased.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a top cover assembly, a single battery cell, and a battery pack. Background Technology

[0002] In related technologies, the tabs of a single battery cell typically need to be bent and welded to a connecting piece, and then electrically connected to a terminal assembly via the connecting piece to enable the cell pack to supply power. However, because bending the tabs occupies internal height space, the volumetric energy density of the battery is relatively low. Utility Model Content

[0003] The present invention provides a top cover assembly, a single battery cell, and a battery pack. The tabs are inserted through the channels of the terminals so that the tabs can directly pass through the cover plate to provide power to the outside. As a result, the tabs do not need to be bent inside the housing, eliminating the height space reserved inside the housing for bending the tabs. This can increase the height of the electrode assembly, thereby increasing the volumetric energy density of the battery.

[0004] In a first aspect, embodiments of the present invention provide a top cover assembly, comprising:

[0005] The cover plate has mounting holes;

[0006] A pole post is inserted through the mounting hole, and the pole post forms a channel for communicating with the inside and outside of the cover plate. The channel is configured for the insertion of a tab.

[0007] A first sealing element is disposed within the mounting hole, and the first sealing element is sleeved onto the pole post.

[0008] In one embodiment, the pole post includes:

[0009] A connecting portion, wherein the channel is formed in the connecting portion, and the first sealing member is sleeved on the connecting portion;

[0010] The abutting part is connected to the periphery of the connecting part and is disposed near the inner side of the cover plate;

[0011] The abutting portion abuts against the first sealing member and compresses the first sealing member.

[0012] In one embodiment, the cover plate includes:

[0013] The first plate has a first through hole;

[0014] The second plate is connected to the first plate. The second plate has a second through hole, which communicates with the first through hole and forms the mounting hole.

[0015] The first sealing element is disposed in the first through hole, and the opposite sides of the first sealing element abut against the second plate and the abutting part, respectively.

[0016] In one embodiment, the compression of the first seal is Δh, which satisfies: 0.605 mm ≤ Δh ≤ 0.825 mm.

[0017] In one embodiment, a groove is formed on the side of the first plate facing the second plate, and a plurality of liquid injection holes are constructed on the bottom surface of the groove. The second plate is provided with liquid injection holes, which are configured to inject electrolyte into the individual battery cell and allow the electrolyte to flow into the groove and then be diverted to the electrode assembly through the plurality of liquid injection holes.

[0018] In one embodiment, the first plate has an extension protruding away from the second plate, the extension being configured to space the abutment portion from the electrode assembly.

[0019] In one embodiment, the top cover assembly further includes:

[0020] A welding plate is disposed on the outside of the cover plate, and the welding plate has a connecting hole. The pole extends out of the mounting hole and is inserted into the connecting hole; wherein the welding plate is configured to be welded to the pole lug.

[0021] In one embodiment, the top cover assembly further includes:

[0022] A welding cover is disposed on the side of the welding plate away from the cover plate;

[0023] The welding cover is sealed to the welding plate, and a receiving cavity is formed between the welding cover and the welding plate, the receiving cavity being configured to receive the electrode tab.

[0024] In one embodiment, the cavity height is H1, and the thickness of the tab located in the cavity is H2, satisfying: H1≥H2+k1, where 0.1 mm≤k1≤0.3 mm.

[0025] In one embodiment, a sealing cavity is further formed between the welding cover and the welding plate, the welding plate having a welding area for welding the electrode tab, the sealing cavity being arranged around the welding area, wherein a second sealing element is provided inside the sealing cavity.

[0026] In one embodiment, the height of the sealing cavity is H3, and the thickness of the second sealing element is D2, satisfying that H3 < D2.

[0027] Secondly, embodiments of this utility model provide a single battery cell, including the top cover assembly as described above.

[0028] In one embodiment, the single battery cell further includes:

[0029] Housing, with the top cover assembly connected to the housing;

[0030] Electrode assembly, disposed within the housing;

[0031] The cover plate has an extension protruding toward the electrode assembly, and the extension is configured to space the electrode post from the electrode assembly.

[0032] In one embodiment, the distance between the pole post and the electrode assembly is X, and the thickness of the tab is H2, satisfying: X≥H2+k2, where 0.1 mm≤k2≤0.3 mm.

[0033] Thirdly, embodiments of this utility model provide a battery pack, including the single battery cell as described above.

[0034] The beneficial effects of the embodiments of this utility model are as follows:

[0035] In this embodiment of the invention, mounting holes are provided on the cover plate to connect the electrode post, and the electrode tab is inserted through the channel formed by the electrode post, allowing the electrode tab to pass from the inside to the outside of the cover plate, thus enabling the core pack to supply power to the outside. A first sealing element is used to seal the connection between the cover plate and the electrode post, achieving a sealed connection between them. Therefore, the electrode tab does not need to be bent inside the housing, eliminating the height space reserved for bending the electrode tab within the housing, allowing for an increase in the height of the electrode assembly, thereby improving the volumetric energy density of the battery. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in an embodiment of this utility model;

[0038] Figure 2 This is a cross-sectional view of a single battery cell provided in an embodiment of this utility model;

[0039] Figure 3 This is an exploded view of the top cover assembly provided in an embodiment of this utility model;

[0040] Figure 4 This is a schematic diagram of the pole structure provided in an embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the structure of the first plate provided in an embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the structure of the second plate provided in an embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the structure of the welding plate provided in an embodiment of this utility model;

[0044] Figure 8 This is a schematic diagram of the structure of the welding cover provided in an embodiment of this utility model.

[0045] Figure label:

[0046] 10-Cover plate, 110-Mounting hole, 120-First plate, 1210-First through hole, 1220-Groove, 1230-Injection port, 1240-Extension, 130-Second plate, 1310-Second through hole, 1320-Injection hole, 140-Third plate, 20-Electrode post, 210-Channel, 220-Connecting part, 230-Abutting part, 30-First seal, 40-Electrode tab, 50-Welding plate, 510-Connecting hole, 520-Welding area, 60-Welding cover, 610-Accommodation cavity, 620-Sealing cavity, 70-Second seal, 80-Housing, 90-Electrode assembly. Detailed Implementation

[0047] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0048] like Figures 1 to 8As shown, this application embodiment provides a top cover assembly. The top cover assembly includes a cover plate 10, a pole post 20, and a first sealing member 30. The cover plate 10 has a mounting hole 110. The pole post 20 passes through the mounting hole 110. The pole post 20 forms a channel 210 for communicating with the inside and outside of the cover plate 10. The channel 210 is configured for a tab 40 to pass through. The first sealing member 30 is disposed in the mounting hole 110 and is sleeved on the pole post 20.

[0049] In this embodiment, the electrode post 20 is connected by providing mounting holes 110 on the cover plate 10, and the electrode tab 40 is passed through the channel 210 formed by the electrode post 20, so that the electrode tab 40 passes from the inside of the cover plate 10 to the outside of the cover plate 10, thereby realizing the external power supply of the core pack. The first sealing member 30 is used to seal the connection between the cover plate 10 and the electrode post 20 to achieve a sealed connection between the cover plate 10 and the electrode post 20. As a result, the electrode tab 40 no longer needs to be bent inside the housing 80, eliminating the height space reserved inside the housing 80 for bending the electrode tab 40, which can increase the height of the electrode assembly 90, thereby increasing the volumetric energy density of the battery.

[0050] Understandably, the cover plate 10 is a plate that covers the housing 80 of the individual battery cell. The mounting holes 110 on the cover plate 10 and the channels 210 formed by the electrode posts 20 cooperate to allow the tabs 40 of the electrode assembly 90 located inside the housing 80 to pass through from the inside to the outside of the cover plate 10. The width of the channel 210 formed in the electrode post 20 is greater than or equal to the total thickness of all the tabs 40 that pass through the channel 210, and the length of the channel 210 formed in the electrode post 20 is greater than or equal to the length of each tab 40 that passes through the channel 210.

[0051] It should be noted that since each battery cell has a positive electrode tab 40 and a negative electrode tab 40, two mounting holes 110 can be formed on the cover plate 10. Each mounting hole 110 is connected to a terminal post 20, and each mounting hole 110 is sealed to the corresponding terminal post 20 through a sealing element. The positive electrode tab 40 extends out of the cover plate 10 through the channel 210 of one terminal post 20, and the negative electrode tab 40 extends out of the cover plate 10 through the channel 210 of the other terminal post 20.

[0052] In some embodiments, since the pole post 20 passes through the mounting hole 110 and the first sealing member 30 is located between the outer surface of the pole post 20 and the wall surface of the mounting hole 110, the size of the mounting hole 110 is slightly larger than the size of the pole post 20. Specifically, when the mounting hole 110 is a square hole and the pole post 20 is configured as a square frame structure, the length of the mounting hole 110 is slightly larger than the length of the pole post 20, and the width of the mounting hole 110 is slightly larger than the width of the pole post 20. When the mounting hole 110 is a circular hole and the pole post 20 is configured as a cylindrical structure, the diameter of the mounting hole 110 is slightly larger than the outer diameter of the pole post 20.

[0053] It should be noted that there is no need to weld between the tab 40 and the pole post 20; the tab 40 only needs to be welded to the welding plate 50 described below.

[0054] In some embodiments, the first seal 30 is a rubber sealing ring. Of course, the first seal 30 can also be made of other materials, as long as it can achieve a sealing effect.

[0055] This embodiment of the application allows the tab 40 to extend directly through the housing 80, rather than bending the tab 40 inside the housing 80 and welding it to the connecting piece. Based on the design method in this embodiment, the gap between the cover plate 10 and the electrode assembly 90 can be reduced to only 1.6 mm. In the solution where the tab 40 is bent, the gap between the cover plate 10 and the electrode assembly 90 is at least 5 mm to 5.5 mm. Therefore, this solution can significantly reduce the reserved space at the top of the electrode assembly 90, increasing the height of the electrode assembly 90 and thus improving the volumetric energy density of the battery.

[0056] like Figure 4 As shown, in some embodiments, the pole post 20 includes a connecting portion 220 and an abutting portion 230. A channel 210 is formed in the connecting portion 220, and a first sealing member 30 is sleeved on the connecting portion 220. The abutting portion 230 is connected to the periphery of the connecting portion 220 and is disposed near the inner side of the cover plate 10. The abutting portion 230 abuts against and compresses the first sealing member 30.

[0057] Understandably, the connecting portion 220, which passes through the mounting hole 110, has a channel 210 formed therein, making the connecting portion 220 a hollow structure. The abutting portion 230 serves as a structure that abuts against the first sealing member 30. Specifically, the first sealing member 30 is fitted onto the connecting portion 220 from the end of the connecting portion 220 away from the abutting portion 230, and the first sealing member 30 abuts against the abutting portion 230 to prevent the first sealing member 30 from detaching from the connecting portion 220.

[0058] In this embodiment, the first sealing member 30 is compressed based on the abutment portion 230, so that the first sealing member 30 can deform horizontally within the through hole. As the first sealing member 30 is compressed thinner, the outer edge and inner edge of the first sealing member 30 form a tight fit with the hole wall surface of the through hole and the outer surface of the connecting portion 220, thereby ensuring that the first sealing member 30 has a good sealing effect.

[0059] In some embodiments, the pole post 20 is made of metal material, and the abutment portion 230 and the connecting portion 220 are integrally formed.

[0060] Please continue reading. Figure 3In some embodiments, the cover plate 10 includes a first plate 120 and a second plate 130. The first plate 120 has a first through hole 1210. The second plate 130 is connected to the first plate 120. The second plate 130 has a second through hole 1310. The second through hole 1310 communicates with the first through hole 1210 and forms a mounting hole 110. A first sealing member 30 is disposed within the first through hole 1210, and the opposite sides of the first sealing member 30 abut against the second plate 130 and the abutment portion 230, respectively.

[0061] Understandably, the first through hole 1210 and the second through hole 1310 serve as two segments of the mounting hole 110. The first sealing member 30 is disposed within the first through hole 1210. Since the opposite sides of the first sealing member 30 abut against the second plate 130 and the abutting portion 230 respectively, the size of the first through hole 1210 is larger than the size of the second through hole 1310, and the size of the first sealing member 30 is larger than the size of the second through hole 1310 but smaller than the size of the first through hole 1210, so that the first sealing member 30 can be disposed within the first through hole 1210 but does not pass through the second through hole 1310. When the first sealing member 30 is pressed against the second plate 130 by the abutting portion 230, the first sealing member 30 is squeezed and deformed to ensure that the first sealing member 30 can achieve a good sealing effect.

[0062] For example, both the first through hole 1210 and the second through hole 1310 are square holes, and the first sealing element 30 is a square sealing ring. Then, the length of the first through hole 1210 is greater than the length of the second through hole 1310, and the length of the first sealing element 30 is less than the length of the first through hole 1210 but greater than the length of the second through hole 1310; the width of the first through hole 1210 is greater than the width of the second through hole 1310, and the width of the first sealing element 30 is less than the width of the first through hole 1210 but greater than the width of the second through hole 1310.

[0063] For example, both the first through hole 1210 and the second through hole 1310 are circular holes, and the first sealing element 30 is an annular sealing ring. Therefore, the diameter of the first through hole 1210 is larger than the diameter of the second through hole 1310, the outer diameter of the first sealing element 30 is smaller than the diameter of the first through hole 1210, and the inner diameter of the first sealing element 30 is larger than the diameter of the second through hole 1310.

[0064] In some embodiments, the first plate 120 is a plastic plate and the second plate 130 is an aluminum plate.

[0065] Please continue reading. Figure 3 In some embodiments, the cover plate 10 further includes a third plate 140, which is connected to the side of the second plate 130 away from the first plate 120. The third plate 140 has a third through hole. The third through hole, the second through hole 1310, and the first through hole 1210 are connected to form the aforementioned mounting hole 110.

[0066] In some embodiments, the size of the third plate 140 is smaller than that of the second plate 130. There may be two third plates 140, which are respectively disposed at positions corresponding to the positive electrode tab 40 and the negative electrode tab 40.

[0067] In some embodiments, the third plate 140 is a plastic plate.

[0068] In some embodiments, the first plate 120 and the third plate 140 can be injection molded to the opposite sides of the second plate 130 to achieve interconnection between the first plate 120, the second plate 130 and the third plate. For example, during the molding stage of the cover plate 10, the second plate 130 is first placed in the injection mold, and the first plate 120 and the third plate 140 are injection molded to the opposite sides of the second plate 130.

[0069] In some embodiments, the first plate 120, the second plate 130, and the third plate 140 may simply be stacked on top of each other. After the connecting portion 220 of the pole post 20 passes through the through hole, the connecting portion 220 can be welded to the welding plate 50 located on the side of the third plate 140 away from the second plate 130. Thus, the first plate 120, the second plate 130, and the third plate 140 are sandwiched between the abutment portion 230 and the welding plate 50, ensuring a reliable connection between the first plate 120, the second plate 130, and the third plate 140.

[0070] In some embodiments, the second plate 130 may be formed by stamping, and an explosion-proof valve is welded onto the second plate 130. The weld penetration depth between the explosion-proof valve and the second plate 130 is set to 0.3 mm to 1 mm, and the weld width is set to 0.7 mm to 1.3 mm.

[0071] In some embodiments, the compression of the first seal 30 is Δh, which satisfies: 0.605 mm ≤ Δh ≤ 0.825 mm.

[0072] It is understandable that when the compression of the first seal 30 is less than 0.605 mm, the sealing effect of the first seal 30 may be poor. Based on the thickness limitation of the first seal 30, the ultimate compression of the first seal 30 is approximately 0.825 mm.

[0073] For example, the compression of the first seal 30 is set to 0.605 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.825 mm, or any value between any two.

[0074] In some embodiments, the thickness of the first seal 30 is D1, which can be set to 1.1 mm.

[0075] like Figure 5 and Figure 6 As shown, in some embodiments, a groove 1220 is formed on the side of the first plate 120 facing the second plate 130. The bottom surface of the groove 1220 is provided with a plurality of liquid injection holes 1230. The second plate 130 is provided with liquid injection holes 1320, which are configured to inject electrolyte into the individual battery cell, and allow the electrolyte to flow into the groove 1220 and then be diverted to the electrode assembly 90 through the plurality of liquid injection holes 1230.

[0076] Understandably, electrolyte can be injected into the individual battery cell through the injection hole 1320. After the electrolyte is injected through the injection hole 1320, it flows into the groove 1220 and then flows along the groove 1220 before being distributed to various positions of the electrode assembly 90 through the injection distribution holes 1230. Based on the arrangement of several injection distribution holes 1230, the electrolyte can be distributed horizontally first, and the position of the electrolyte dripping into the electrode assembly 90 can be controlled.

[0077] For example, the groove 1220 may include a first groove segment, a second groove segment, and a third groove segment arranged sequentially at intervals along the length direction of the first plate 120, a fourth groove segment connecting the first groove segment and the second groove segment, and a fifth groove segment connecting the second groove segment and the third groove segment. The first, second, and third groove segments all extend along the width direction of the first plate 120, while the fourth and fifth groove segments all extend along the length direction of the first plate 120.

[0078] In some embodiments, the first plate 120 is provided with two first through holes 1210 for the positive electrode tab 40 and the negative electrode tab 40 to pass through, respectively. One first through hole 1210 is located between the first slot segment and the second slot segment, and the other first through hole 1210 is located between the second slot segment and the third slot segment. There may be two fourth slot segments, each located on opposite sides of one first through hole 1210. There may also be two fifth slot segments, each located on opposite sides of another first through hole 1210.

[0079] It should be noted that the bottom surfaces of the first, second, third, fourth, and fifth tank sections are all provided with liquid injection orifices 1230. Based on the arrangement and distribution of the first, second, third, fourth, and fifth tank sections, electrolyte can be dripped into various positions in the horizontal direction of the electrode assembly 90, thereby improving the wetting efficiency of the electrolyte. The shapes of the liquid injection orifices 1230 in each tank section may be the same or different. For example, the liquid injection orifices 1230 can be set as circular holes, strip-shaped holes, etc.

[0080] like Figure 5As shown, in some embodiments, the first plate 120 has an extension 1240 protruding in a direction away from the second plate 130. The extension 1240 is configured to space the abutment portion 230 from the electrode assembly 90.

[0081] Understandably, when the cover plate 10 is installed on the housing 80, the extension 1240 can abut against the electrode assembly 90, or the extension 1240 can abut against the overlapping structure on the inner surface of the housing 80, so that the abutment portion 230 and the electrode assembly 90 are spaced apart. Thus, the gap between the abutment portion 230 and the diaphragm of the electrode assembly 90 provides sufficient space for the tab 40 to pass through the channel 210 of the electrode post 20, and prevents the electrode from contacting the electrode post 20 due to compression. Furthermore, this gap also serves as a space for temporarily storing the electrolyte, allowing the electrolyte to temporarily reside within this gap and gradually permeate the electrode assembly 90 downwards.

[0082] It should be noted that the gap between the contact portion 230 and the diaphragm can be set to 0.4 mm. Alternatively, the gap between the contact portion 230 and the diaphragm can be X, and the thickness of the tab 40 can be H2, satisfying: X≥H2+k2, where 0.1 mm≤k2≤0.3 mm.

[0083] For example, if the thickness of the tab 40 is set to 0.2 mm and the value of k2 is 0.2 mm, then the distance between the contact portion 230 and the diaphragm is greater than or equal to 0.4 mm. In this case, the distance between the contact portion 230 and the diaphragm can be set to values ​​such as 0.4 mm or 0.5 mm.

[0084] For example, k2 can be set to 0.1 mm, 0.2 mm, 0.3 mm, or any value in between.

[0085] Please continue reading. Figure 3 In some embodiments, the top cover assembly further includes a welding plate 50. The welding plate 50 is disposed on the outer side of the cover plate 10. The welding plate 50 has a connection hole 510. The pole post 20 extends out of the mounting hole 110 and is disposed within the connection hole 510. The welding plate 50 is configured to be welded to the tab 40.

[0086] Understandably, the welding plate 50 is used to weld with the tab 40 so that the tab 40 can output electrical energy through the welding plate 50. Specifically, after passing through the channel 210 of the pole post 20, the tab 40 can be bent and welded to the side of the welding plate 50 away from the cover plate 10. For example, the connecting hole 510 extends along the length of the welding plate 50, dividing the welding plate 50 into a left and right region. When the tab 40 passes through the channel 210 of the pole post 20, a portion of the tab 40 bends to the left and lies flat in the left region of the welding plate 50, and is welded to the left region of the welding plate 50; another portion of the tab 40 bends to the right and lies flat in the right region of the welding plate 50, and is welded to the right region of the welding plate 50.

[0087] It should be noted that the outer side of the cover plate 10 refers to the side of the cover plate 10 away from the electrode assembly 90, and the inner side of the cover plate 10 refers to the side of the cover plate 10 facing the electrode assembly 90.

[0088] In some embodiments, two welding plates 50 are provided, and the two welding plates 50 correspond to the positive electrode tab 40 and the negative electrode tab 40, respectively. The thickness of the welding plate 50 welded to the positive electrode tab 40 can be set to 1.5 mm, and the welding plate 50 can be an aluminum plate. The thickness of the welding plate 50 welded to the negative electrode tab 40 can be set to 1.5 mm, and the welding plate 50 can be a copper-aluminum composite plate, wherein the copper layer is 1 mm thick and the aluminum layer is 0.5 mm thick.

[0089] In some embodiments, the tab 40 is welded to the welding plate 50 by laser welding. The weld penetration depth between the tab 40 and the welding plate 50 can be set to 0.5 mm to 0.9 mm. This prevents burn-through between the tab 40 and the welding plate 50 and ensures the reliability of the weld between them.

[0090] It should be noted that there is no direct connection between the welding plate 50 and the cover plate 10; the welding plate 50 is simply placed on the upper side of the cover plate 10. After the connecting part 220 of the pole post 20 passes through the through hole, the connecting part 220 can be welded to the welding plate 50.

[0091] Please continue reading. Figure 3 In some embodiments, the top cover assembly further includes a welding cover 60. The welding cover 60 is disposed on the side of the welding plate 50 away from the cover plate 10. The welding cover 60 is sealed to the welding plate 50, and a receiving cavity 610 is formed between the welding cover 60 and the welding plate 50. The receiving cavity 610 is configured to receive the tab 40.

[0092] It is understood that the welding cover 60 is welded to the welding plate 50 so that the welding cover 60 and the welding plate 50 cooperate to form a positive terminal sub-assembly or a negative terminal sub-assembly. Based on the receiving cavity 610 formed between the welding cover 60 and the welding plate 50, the receiving cavity 610 is used to receive the tab 40 that is bent and welded to the welding plate 50.

[0093] It should be noted that a recessed area can be provided on the side of the welding cover 60 facing the welding plate 50. When the welding cover 60 is closed on the welding plate 50, this recessed area can form a receiving cavity 610 located between the welding plate 50 and the welding cover 60. Alternatively, a recessed area can be provided on the side of the welding plate 50 facing the welding cover 60. When the welding cover 60 is closed on the welding plate 50, this recessed area can form a receiving cavity 610 located between the welding plate 50 and the welding cover 60. Alternatively, a recessed area can be provided on the side of the welding cover 60 facing the welding plate 50, and another recessed area can be provided on the side of the welding plate 50 facing the welding cover 60. When the welding cover 60 is closed on the welding plate 50, the two recessed areas are connected and form a receiving cavity 610 located between the welding plate 50 and the welding cover 60.

[0094] It should be noted that the welding cover 60 is welded to the welding plate 50. For example, the welding cover 60 is laser welded to the welding plate 50, and the width of the weld is set to 0.8 mm to 1.3 mm.

[0095] In some embodiments, the cavity height of the accommodating cavity 610 is H1, and the thickness of the tab 40 located in the accommodating cavity 610 is H2, satisfying: H1≥H2+k1, where 0.1 mm≤k1≤0.3 mm.

[0096] Understandably, the height of the accommodating cavity 610 is greater than the thickness of the tab 40 to prevent the welding cover 60 and welding plate 50 from damaging the tab 40.

[0097] It should be noted that the cavity height of the accommodating cavity 610 can be equal to the sum of the thickness of the tab 40 and k1, so that the cavity height of the accommodating cavity 610 is only slightly greater than that of the tab 40. Since the deeper the cavity height of the accommodating cavity 610, the thicker the welding plate 50 and / or welding cover 60 will be. When the total height of the single cell remains unchanged, the greater the thickness of the welding plate 50 and / or welding cover 60, the smaller the height of the electrode assembly 90 will be, resulting in a decrease in the energy density of the single cell.

[0098] For example, if the thickness of the tab 40 is set to 0.2 mm and the value of k1 can be set to 0.1 mm, then the cavity height of the accommodating cavity 610 is set to 0.3 mm.

[0099] For example, the value of k1 can be set to 0.1 mm, 0.2 mm, 0.3 mm, or any value between the two.

[0100] Please continue reading. Figure 7 and Figure 8 In some embodiments, a sealing cavity 620 is formed between the welding cover 60 and the welding plate 50. The welding plate 50 has a welding area 520 for welding the electrode tab 40. The sealing cavity 620 is arranged around the welding area 520. A second sealing element 70 is provided inside the sealing cavity 620.

[0101] Understandably, the sealing cavity 620 between the welding cover 60 and the welding plate 50 is used to house the second sealing element 70. Since the sealing cavity 620 is arranged around the welding area 520 on the welding plate 50, the second sealing element 70 can ensure the sealing performance of the tab 40. The sealing cavity 620 can be a rectangular cavity arranged around the welding area 520, in which case the second sealing element 70 is a rectangular sealing ring. Alternatively, the sealing cavity 620 can be an annular cavity arranged around the welding area 520, in which case the second sealing element 70 is an annular sealing ring.

[0102] In some embodiments, the second seal 70 is a rubber sealing ring. Of course, the second seal 70 can also be made of other materials, as long as it can achieve a sealing effect.

[0103] In some embodiments, an annular sealing groove can be constructed on the side of the welding cover 60 facing the welding plate 50, and the sealing groove is arranged around the welding area 520 of the welding plate 50. When the welding cover 60 is closed on the welding plate 50, the sealing groove is closed by the welding plate 50 to form the aforementioned sealing cavity 620. Alternatively, an annular sealing groove can be constructed on the side of the welding plate 50 facing the welding cover 60, and the sealing groove is arranged around the welding area 520 of the welding plate 50. When the welding cover 60 is closed on the welding plate 50, the sealing groove is closed by the welding cover 60 to form the aforementioned sealing cavity 620. Alternatively, an annular sealing groove can be constructed on the side of the welding cover 60 facing the welding plate 50, and another annular sealing groove can be constructed on the side of the welding plate 50 facing the welding cover 60, both sealing grooves being arranged around the welding area 520 of the welding plate 50. When the welding cover 60 is closed on the welding plate 50, the two sealing grooves abut and form the aforementioned sealing cavity 620.

[0104] In some embodiments, the cavity height of the sealing cavity 620 is H3, and the thickness of the second sealing member 70 is D2, satisfying: H3 < D2.

[0105] It is understandable that the height of the sealing cavity 620 is less than the thickness of the second seal 70 in order to ensure that the second seal 70 can provide a reliable sealing effect.

[0106] For example, the thickness of the second seal 70 is set to 0.8 mm, and the height of the sealing cavity 620 is set to 0.6 mm, thereby enabling the sealing cavity 620 to compress the second seal 70 to ensure that the second seal 70 can provide a reliable sealing effect.

[0107] For example, the thickness of the second seal 70 is set to 0.8 mm. At this time, an annular sealing groove is constructed on the side of the welding cover 60 facing the welding plate 50, and the groove depth is 0.3 mm. Another annular sealing groove is constructed on the side of the welding plate 50 facing the welding cover 60, and this groove depth is also 0.3 mm. When the welding cover 60 is closed onto the welding plate 50, the two sealing grooves abut and form a sealing cavity 620 with a height of 0.6 mm, allowing the sealing cavity 620 to compress the second seal 70, ensuring that the second seal 70 provides a reliable sealing effect.

[0108] like Figure 1 and Figure 2 As shown in the embodiments, this application also provides a single battery cell. This single battery cell includes the top cover assembly as described in the foregoing embodiments.

[0109] In this embodiment, the electrode post 20 is connected by providing mounting holes 110 on the cover plate 10, and the electrode tab 40 is passed through the channel 210 formed by the electrode post 20, so that the electrode tab 40 passes from the inside of the cover plate 10 to the outside of the cover plate 10, thereby realizing the external power supply of the core pack. The first sealing member 30 is used to seal the connection between the cover plate 10 and the electrode post 20 to achieve a sealed connection between the cover plate 10 and the electrode post 20. As a result, the electrode tab 40 no longer needs to be bent inside the housing 80, eliminating the height space reserved inside the housing 80 for bending the electrode tab 40, which can increase the height of the electrode assembly 90, thereby increasing the volumetric energy density of the battery.

[0110] Please continue reading. Figure 1 and Figure 2 In some embodiments, the individual battery cell further includes a housing 80 and an electrode assembly 90. A top cover assembly is connected to the housing 80. The electrode assembly 90 is disposed within the housing 80. The cover plate 10 has an extension 1240 protruding toward the electrode assembly 90. The extension 1240 is configured to space the electrode post 20 from the electrode assembly 90.

[0111] Understandably, when the cover plate 10 is installed on the housing 80, the extension 1240 of the electrode post 20 can abut against the electrode assembly 90, or the extension 1240 of the electrode post 20 can abut against the overlapping structure on the inner surface of the housing 80, so that the electrode post 20 and the electrode assembly 90 are spaced apart. Thus, the gap between the electrode post 20 and the electrode assembly 90 provides sufficient space for the tab 40 to pass through the channel 210 of the electrode post 20, and prevents the electrode from contacting the electrode post 20 due to compression. Furthermore, this gap also serves as a space for temporarily storing the electrolyte, allowing the electrolyte to temporarily reside within this gap and gradually wet the electrode assembly 90.

[0112] For example, the spacing between the pole post 20 and the electrode assembly 90 can be set to 0.4 mm.

[0113] In some embodiments, the distance between the electrode post 20 and the electrode assembly 90 is X, and the thickness of the electrode tab 40 is H2, satisfying: X≥H2+k2, where 0.1 mm≤k2≤0.3 mm.

[0114] For example, if the thickness of the tab 40 is set to 0.2 mm and the value of k2 is 0.2 mm, then the distance between the electrode post 20 and the electrode assembly 90 is greater than or equal to 0.4 mm. In this case, the distance between the electrode post 20 and the electrode assembly 90 can be set to values ​​such as 0.4 mm and 0.5 mm.

[0115] For example, k2 can be set to 0.1 mm, 0.2 mm, 0.3 mm, or any value in between.

[0116] This application also provides a battery pack. The battery pack includes individual battery cells as described in the foregoing embodiments.

[0117] In this embodiment, the electrode post 20 is connected by providing mounting holes 110 on the cover plate 10, and the electrode tab 40 is passed through the channel 210 formed by the electrode post 20, so that the electrode tab 40 passes from the inside of the cover plate 10 to the outside of the cover plate 10, thereby realizing the external power supply of the core pack. The first sealing member 30 is used to seal the connection between the cover plate 10 and the electrode post 20 to achieve a sealed connection between the cover plate 10 and the electrode post 20. As a result, the electrode tab 40 no longer needs to be bent inside the housing 80, eliminating the height space reserved inside the housing 80 for bending the electrode tab 40, which can increase the height of the electrode assembly 90, thereby increasing the volumetric energy density of the battery.

[0118] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. 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 utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A top cover assembly, characterized in that, include: The cover plate has mounting holes; A pole post is inserted through the mounting hole, and the pole post forms a channel for communicating with the inside and outside of the cover plate. The channel is configured for the insertion of a tab. A first sealing element is disposed in the mounting hole, and the first sealing element is sleeved on the pole post; The pole includes a connecting part and an abutting part. The channel is formed in the connecting part, and the first sealing member is sleeved on the connecting part. The abutting part is connected to the periphery of the connecting part and is disposed near the inner side of the cover plate. The cover plate includes a first plate and a second plate connected together. The first plate has a first through hole, and the second plate has a second through hole. The second through hole communicates with the first through hole and forms the mounting hole.

2. The top cover assembly according to claim 1, characterized in that, The first sealing element is disposed in the first through hole, and the opposite sides of the first sealing element abut against the second plate and the abutting part, respectively.

3. The top cover assembly according to claim 2, characterized in that, The compression of the first seal is Δh, which satisfies the following condition: 0.605 mm ≤ Δh ≤ 0.825 mm.

4. The top cover assembly according to claim 2, characterized in that, The first plate has a groove formed on the side facing the second plate. The bottom surface of the groove has a plurality of liquid injection holes. The second plate has liquid injection holes configured to inject electrolyte into the individual cell and to allow the electrolyte to flow into the groove and then be distributed to the electrode assembly through the plurality of liquid injection holes.

5. The top cover assembly according to claim 2, characterized in that, The first plate has an extension protruding away from the second plate, the extension being configured to space the abutment portion from the electrode assembly.

6. The top cover assembly according to any one of claims 1 to 5, characterized in that, The top cover assembly also includes: A welding plate is disposed on the outside of the cover plate, and the welding plate has a connecting hole. The pole extends out of the mounting hole and is inserted into the connecting hole; wherein the welding plate is configured to be welded to the pole lug.

7. The top cover assembly according to claim 6, characterized in that, The top cover assembly also includes: A welding cover is disposed on the side of the welding plate away from the cover plate; The welding cover is sealed to the welding plate, and a receiving cavity is formed between the welding cover and the welding plate, the receiving cavity being configured to receive the electrode tab.

8. The top cover assembly according to claim 7, characterized in that, The cavity height is H1, and the thickness of the tab inside the cavity is H2, satisfying: H1≥H2+k1, where 0.1 mm≤k1≤0.3 mm.

9. The top cover assembly according to claim 7, characterized in that, A sealing cavity is also formed between the welding cover and the welding plate. The welding plate has a welding area for welding the electrode tab. The sealing cavity is arranged around the welding area, and a second sealing element is provided inside the sealing cavity.

10. The top cover assembly according to claim 9, characterized in that, The height of the sealed cavity is H3, and the thickness of the second sealing element is D2, satisfying that H3 < D2.

11. A single battery cell, characterized in that, Includes the top cover assembly as described in any one of claims 1 to 10.

12. The single-cell battery according to claim 11, characterized in that, The single battery cell also includes: Housing, with the top cover assembly connected to the housing; Electrode assembly, disposed within the housing; The cover plate has an extension protruding toward the electrode assembly, and the extension is configured to space the electrode post from the electrode assembly.

13. The single-cell battery according to claim 12, characterized in that, The distance between the pole post and the electrode assembly is X, and the thickness of the tab is H2, satisfying: X≥H2+k2, where 0.1 mm≤k2≤0.3 mm.

14. A battery pack, characterized in that, Including the single cell as described in any one of claims 11 to 13.

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