Cover plate assembly and battery cell

Abstract

The utility model relates to the technical field of batteries, particularly provides a cover plate assembly and a battery cell, and aims to solve the problem that a first insulating part in an existing cover plate assembly is relatively high. In order to achieve the purpose, the cover plate assembly comprises a cover plate, a first insulating part, a pole and a switching piece, the first insulating part is located on one side of the cover plate, and a containing groove is formed in one side of the first insulating part; the pole penetrates through the first insulating part and the cover plate from one side, far away from the cover plate, of the first insulating part and then is exposed; the switching piece is located in the containing groove and electrically connected with the pole and the tab, and a part of the tab is located between the switching piece and the first insulating part. Therefore, the tab is in a clamped compression state, so that the space occupied by the tab is small, and the maximum depth of the accommodating groove is reduced, that is, the maximum height of the first insulating part can be reduced, and the maximum height of the corresponding cover plate assembly is reduced; and under the condition of the same size of the shell, the maximum height of the pole group can be set to be larger, and the capacity of the corresponding battery core is larger.

Description

Technical Field

[0001] This utility model relates to the technical field of batteries, specifically providing a cover plate assembly and a battery cell. Background Technology

[0002] With the development of new energy sources, lithium battery technology is constantly being upgraded. The rigid structural components of a lithium battery cell can be broadly divided into cylindrical and square structures, mainly including the casing, cover assembly, connectors, and base plate. The cover assembly plays a crucial role in the lithium battery cell. The electrode assembly is placed inside the casing, with both ends supported and protected by the cover assembly and the base plate. For square structures, the side of the electrode assembly with the tabs faces the cover assembly.

[0003] The cover plate assembly includes a cover plate, a first insulating member, a pole post, and an adapter plate. The first insulating member is located on one side of the cover plate. The pole post passes through the first insulating member and the cover plate from the side away from the cover plate and then protrudes. The adapter plate is disposed on the side of the first insulating member away from the cover plate and is electrically connected to the pole post. The adapter plate is electrically connected to the tabs of the pole assembly.

[0004] In existing cover plate assemblies, the first insulating component is relatively tall, taking up a large amount of space, which is not conducive to increasing the capacity of the battery cell. Utility Model Content

[0005] The present invention aims to solve the above-mentioned technical problem, namely, to solve the problem of the high height of the first insulating component in the existing cover plate assembly.

[0006] In a first aspect, the present invention provides a cover plate assembly electrically connected to the tabs of an electrode assembly, comprising: a cover plate; a first insulating member located on one side of the cover plate, having a receiving groove on one side; an electrode post extending from the side of the first insulating member away from the cover plate, passing through the first insulating member and the cover plate and then protruding; and an adapter piece located within the receiving groove, electrically connected to the electrode post and the tabs, wherein a portion of the tabs is located between the adapter piece and the first insulating member.

[0007] In a specific embodiment of the above-mentioned cover plate assembly, the cover plate assembly further includes a snap-fit ​​member, which is fixed to the side of the first insulating member away from the cover plate. A snap-fit ​​groove is formed between the snap-fit ​​member and the first insulating member, and a portion of the adapter piece is accommodated in the snap-fit ​​groove to constrain the adapter piece.

[0008] In a specific embodiment of the above-mentioned cover plate assembly, the snap-fit ​​component and the first insulating component are made of plastic, and the snap-fit ​​component and the first insulating component are ultrasonically welded together.

[0009] In a specific embodiment of the above cover plate assembly, the adapter plate includes an integrally connected pole contact portion and a tab contact portion. The pole contact portion contacts the pole to achieve electrical connection, and the tab contact portion contacts the tab to achieve electrical connection.

[0010] In a specific embodiment of the above cover plate assembly, the tab contact portion includes two tabs, both located on the same side of the pole contact portion, and each tab contact portion contacts at least one set of tabs.

[0011] In a specific embodiment of the above-mentioned cover plate assembly, the corners of the electrode contact portion are rounded.

[0012] In a specific embodiment of the above-mentioned cover plate assembly, the cover plate assembly further includes an explosion-proof valve, which is installed on the cover plate and corresponds to the exhaust hole provided on the cover plate. The first insulating member is provided with an exhaust port corresponding to the explosion-proof valve.

[0013] In a second aspect, the present invention provides a battery cell, including an electrode assembly and the aforementioned cover plate assembly, wherein the electrode assembly includes a tab, a portion of which is located between an adapter plate and a cover plate.

[0014] In a specific embodiment of the above-mentioned battery cell, the battery cell further includes: a housing, the electrode group being housed within the housing, and the cover plate assembly being located at one end of the housing; and an insulating membrane being located between the housing and the electrode group, with one end located between the cover plate and the first insulating member.

[0015] In the specific embodiment of the above-mentioned battery cell, the housing is a square housing, the positive and negative tabs of the electrode group are both located at the same end of the electrode group near the cover plate assembly, and the adapter includes a positive adapter electrically connected to the positive tab and a negative adapter electrically connected to the negative tab.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The cover plate assembly of this utility model includes a cover plate, a first insulating member, an electrode post, and an adapter plate. The first insulating member is located on one side of the cover plate, and a receiving groove is formed on one side of it. The electrode post passes through the first insulating member and the cover plate from the side away from the cover plate and then protrudes. The adapter plate is located in the receiving groove and is electrically connected to the electrode post and the electrode tab, with a portion of the electrode tab located between the adapter plate and the first insulating member. Because the electrode tab is fixed by the adapter plate and the first insulating member, the electrode tab is in a clamped and compressed state. Therefore, the space occupied by the electrode tab is smaller, the maximum depth required for the receiving groove is reduced, that is, the maximum height of the first insulating member can be reduced, and the maximum height of the cover plate assembly is reduced accordingly. With the same housing size, after the maximum height of the cover plate assembly is reduced, the maximum height of the electrode group can be set larger, and the corresponding cell capacity is larger. Attached Figure Description

[0018] The preferred embodiments of this utility model are described below with reference to the accompanying drawings, in which:

[0019] Figure 1 This is an exploded structural diagram of the battery cell provided by this utility model;

[0020] Figure 2 This is an exploded structural diagram of the cover plate assembly provided by this utility model;

[0021] Figure 3 This is a cross-sectional structural diagram of the battery cell provided by this utility model;

[0022] Figure 4 yes Figure 3 Enlarged view of part A in the image;

[0023] Figure 5 This is a three-dimensional structural schematic diagram of the cover plate assembly provided by this utility model;

[0024] Figure 6 This is a partial cross-sectional view of the cover plate assembly provided by this utility model;

[0025] Figure 7 This is a structural diagram of the adapter plate provided by this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Electrode assembly; 11. Electrode tab; 111. Positive electrode tab; 112. Negative electrode tab; 2. Housing; 3. Base plate; 4. Isolation membrane; 5. Cover plate assembly; 51. Cover plate; 511. Vent hole; 52. First insulating component; 521. Receiving groove; 522. Mounting hole; 523. Vent port; 53. Second insulating component; 54. Electrode post; 541. Positive electrode post; 542. Negative electrode post; 540. Sealing ring; 55. Adapter piece; 551. Positive electrode adapter piece; 552. Negative electrode adapter piece; 553. Electrode post contact part; 554. Electrode tab contact part; 56. Snap-fit ​​component; 561. Snap-fit ​​groove; 57. Explosion-proof valve; 58. Explosion-proof valve protection plate; 6. Top patch; 501. Sealing aluminum nail; 502. Adhesive nail; 7. Blue film. Detailed Implementation

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that in the description of this utility model, the terms "upper," "lower," "left," "right," "inner," and "outer," which indicate directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" 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 direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] The battery cell includes an electrode assembly, a housing, a cover plate assembly, a base plate, and a separator. The electrode assembly is placed inside the housing, and its two ends are supported and protected by the cover plate assembly and the base plate. The separator is located between the housing and the electrode assembly; its first end is fixed and sealed to the cover plate assembly, and its second end is fixed and sealed to the base plate. For prismatic cells, the positive and negative electrode tabs in the electrode assembly are located on one side and both face the cover plate assembly.

[0032] The cover plate assembly includes a cover plate, a first insulator, a terminal post, and an adapter plate. The first insulator is located on one side of the cover plate, and the terminal post protrudes from the side of the first insulator away from the cover plate, passing through the first insulator and the cover plate. An edge portion of the first insulator protrudes towards the side away from the cover plate, forming a receiving groove on one side of the first insulator. The adapter plate is located within the receiving groove and is electrically connected to the terminal post. The adapter plate includes a positive adapter plate and a negative adapter plate, and the terminal post includes a positive terminal post and a negative terminal post. The positive adapter plate is electrically connected to the positive tab and the positive terminal post to bridge the positive tab and the positive terminal post, and the negative adapter plate is electrically connected to the negative tab and the negative terminal post to bridge the negative tab and the negative terminal post.

[0033] The positive electrode tab is located on the side of the positive electrode adapter away from the first insulator and is welded to the positive electrode adapter. The negative electrode tab is located on the side of the negative electrode adapter away from the first insulator and is welded to the negative electrode adapter. During charging and discharging, the cell temperature easily rises, causing the positive and negative electrode tabs to expand and easily loosen. Therefore, the depth of the receiving groove needs to be increased to accommodate the positive and negative electrode tabs. Correspondingly, the height of the first insulator is relatively high, occupying a large space. Given a fixed overall cell size, the maximum height of the electrode group that can be set is correspondingly reduced, which is not conducive to increasing the cell capacity.

[0034] In addition, loose positive and negative electrodes may be inserted into the electrode assembly in reverse, which could cause a short circuit in the battery cell.

[0035] Based on this, the present invention provides a cover plate assembly electrically connected to the electrode tabs of an electrode assembly, comprising: a cover plate; a first insulating member located on one side of the cover plate, wherein the middle portion has a receiving groove; an electrode post extending from the side of the first insulating member away from the cover plate, passing through the first insulating member and the cover plate and then protruding; and an adapter piece located in the receiving groove, electrically connected to the electrode post and the electrode tabs, wherein a portion of the electrode tabs is located between the adapter piece and the first insulating member.

[0036] The cover plate assembly and the battery cell having the above cover plate assembly will be described below through specific embodiments.

[0037] like Figure 1 As shown, this utility model provides a battery cell, including an electrode assembly 1, a housing 2, a cover plate assembly 5, a bottom support plate 3, and a separator 4. The electrode assembly 1, also known as a bare battery cell, includes tabs 11 arranged in groups, with the tabs of each group aligned and electrically connected. The electrode assembly 1 is placed inside the housing 2, and its two ends are supported and protected by the cover plate assembly 5 and the bottom support plate 3. The separator 4 is located between the housing 2 and the electrode assembly 1; its first end is fixed and sealed to the cover plate assembly 5, and its second end is fixed and sealed to the bottom support plate 3.

[0038] The battery cell also includes a top patch 6, which is located on the side of the cover assembly 5 away from the electrode group 1. The cover assembly 5 is also provided with sealing aluminum nails 501 and adhesive nails 502 for sealing. The outer side of the housing 2 is covered with a blue film 7.

[0039] like Figure 1 and Figure 2 As shown, the cover plate assembly 5 of this utility model includes a cover plate 51, a first insulating member 52, a second insulating member 53, a pole post 54, and an adapter piece 55. The first insulating member 52 is located on one side of the cover plate 51, and the pole post 54 passes through the first insulating member 52 and the cover plate 51 from the side of the first insulating member 52 away from the cover plate 51 and then protrudes. The edge of the first insulating member 52 protrudes towards the side away from the cover plate 51, forming a receiving groove 521 on the side of the first insulating member 52 away from the cover plate 51. The adapter piece 55 is located in the receiving groove 521 and is electrically connected to the pole post 54, which can be achieved by laser welding. An insulating sealing ring 540 is fitted on the pole post 54 to isolate the pole post 54 and the cover plate 51. The second insulating member 53 is located on the side of the cover plate 51 away from the first insulating member 52 and corresponds to the pole post 54.

[0040] In a specific example of this utility model, the first end of the separator 4 is located between the first insulating member 52 and the cover plate 51 to achieve sealing and fixation. This arrangement of the separator 4 does not impose very strict requirements on the height of the first insulating member 52, thereby reducing the height of the first insulating member 52 and correspondingly reducing the maximum height of the cover plate assembly 5. With the same housing size, after reducing the maximum height of the cover plate assembly 5, the maximum height of the electrode group 1 can be set larger, and the corresponding cell capacity is larger.

[0041] Of course, in other possible implementations, the separator 4 can also be fitted around the outer periphery of the first insulating member 52, and then the separator 4 and the first insulating member 52 can be sealed and fixed by heat fusion. However, this arrangement of the separator 4 requires a certain height of the first insulating member 52; otherwise, the reliability of the connection between the separator 4 and the first insulating member 52 after heat fusion cannot be guaranteed, which is not conducive to improving the capacity of the battery cell.

[0042] like Figure 3 and Figure 4 As shown, a portion of each set of tabs 11 facing the cover assembly 5 is located between the adapter piece 55 and the first insulator 52, and each set of tabs 11 is fixed by the adapter piece 55 and the first insulator 52. Since a portion of each set of tabs 11 is located between the adapter piece 55 and the first insulator 52, the tabs 11 are in a clamped and constrained state. Therefore, the space occupied by the tabs 11 is smaller, the maximum depth required for the receiving groove 521 is reduced, that is, the maximum height of the first insulator 52 can be reduced, and the overall height of the cover assembly 5 is lower. With the same size of housing 2, the lower the overall height of the cover assembly 5, the greater the maximum height that the electrode group 1 can be set, and the larger the corresponding cell capacity.

[0043] Furthermore, the end of the tab 11 is fixed and away from the electrode group 1, ensuring that the tab 11 is almost never loose, reducing the possibility of the tab 11 being inserted backwards into the electrode group 1, thereby improving the safety of the battery cell. In addition, since the tab 11 is constrained between the adapter piece 55 and the first insulator 52, and there is a certain gap between the adapter piece 55 and the first insulator 52, the pole post 54 needs to be moved towards the adapter piece 55 to compensate for this. This reduces the height of the pole post 54 beyond the cover plate 51, thus lowering the overall height of the cover plate assembly 5. With the same housing size, the lower the overall height of the cover plate assembly 5, the greater the maximum height that the electrode group 1 can be set to, and the larger the corresponding battery cell capacity.

[0044] Taking square battery cells as an example, combined with Figure 1 and Figure 2As shown, the housing 2 is square, and the positive electrode tab 111 and negative electrode tab 112 of the electrode group 1 are both located at the same end of the electrode group 1 facing the cover plate assembly 5. The adapter piece 55 includes a positive electrode adapter piece 551 and a negative electrode adapter piece 552, and the terminal 54 includes a positive terminal 541 and a negative terminal 542. The positive electrode adapter piece 551 is electrically connected to the positive electrode tab 111 and the positive terminal 541 to bridge the positive electrode tab 111 and the positive terminal 541, and the negative electrode adapter piece 552 is electrically connected to the negative electrode tab 112 and the negative terminal 542 to bridge the negative electrode tab 112 and the negative terminal 542.

[0045] In a specific example of this utility model, such as Figure 5 and Figure 6 As shown, the cover plate assembly 5 also includes a snap-fit ​​member 56, which is fixed to the side of the first insulating member 52 away from the cover plate 51. A snap-fit ​​groove 561 is formed between the snap-fit ​​member 56 and the first insulating member 52. A portion of the adapter piece 55 is accommodated in the snap-fit ​​groove 561, thereby constraining the adapter piece 55.

[0046] Both the first insulating member 52 and the cover plate 51 are made of plastic. The cover plate 51 has a mounting hole 522 for mounting the snap-fit ​​member 56. The snap-fit ​​member 56 is L-shaped, with one side installed in the mounting hole 522 and the other side parallel to the first insulating member 52, thus forming a snap-fit ​​groove 561 between the first insulating member 52 and the snap-fit ​​member 56. After the snap-fit ​​member 56 is installed into the mounting hole 522, the snap-fit ​​member 56 and the first insulating member 52 are welded and fixed by ultrasonic welding (also known as vibration friction welding).

[0047] Specifically, the ultrasonic welding equipment converts electrical energy into a high-frequency, high-voltage signal, which is then converted into high-frequency mechanical vibration through a transducer system. This vibration is transmitted through the welding head to the first insulating component 52 and the snap-fit ​​component 56, causing frictional heat and localized melting at their contact surfaces. During the welding process, a certain pressure is typically applied to ensure a tight fit between the contact surfaces of the first insulating component 52 and the snap-fit ​​component 56. After the ultrasonic waves cease, the first insulating component 52 and the snap-fit ​​component 56 cool and solidify under pressure, thus achieving the welding process.

[0048] like Figure 7As shown, the adapter 55 includes an integrally connected pole contact portion 553 and a tab contact portion 554. The pole contact portion 553 contacts and is welded to the pole 54 to achieve electrical connection. The tab contact portion 554 is accommodated in the snap-fit ​​groove 561 and is snapped and fixed by the snap-fit ​​member 56. A single set of tabs 11 is located between the tab contact portion 554 and the first insulating member 52 and is welded to the tab contact portion 554 to achieve electrical connection. First, clamp the end of the tab 11 between the tab contact 554 and the first insulating member 52. Then, gradually move the adapter piece 55 so that the end of the tab contact 554 is accommodated in the snap-fit ​​groove 561 and the pole contact 553 corresponds to the pole 54. This provides initial constraint on the adapter piece 55 to prevent it from moving. Then, weld the pole contact 553 to the pole 54 and the tab contact 554 to the tab 11 to fix the adapter piece 55 to the pole 54 and the adapter piece 55 to the tab 11.

[0049] Since the tab 11 is very thin, mostly made of aluminum foil or copper foil, its strength is low. In order to prevent the tab contact 554 from cutting off the tab 11 during the movement of the adapter 55, the corners (i.e., edges) of the tab contact 554 can be set as rounded corners.

[0050] In a specific example of this utility model, the tab contact portion 554 includes two parts, which are respectively located at both ends of the pole contact portion 553, making the adapter piece 55 generally U-shaped. The electrode group 1 includes multiple groups of a single type of tab 11 (such as positive tab 111 or negative tab 112), at least one group of tabs 11 is electrically connected to a single tab contact portion 554, and the different groups of tabs 11 connected to the same adapter piece 55 are of the same type.

[0051] like Figure 2 As shown, a vent 511 is provided on the cover plate 51. An explosion-proof valve 57 is installed at the vent 511 on the cover plate 51, and a corresponding vent 523 is provided on the first insulating component 52. During charging and discharging, the electrode group 1 generates heat and releases gas. The heat released by the electrode group 1 can be discharged from the battery cell through the explosion-proof valve 57 to improve the safety of the battery cell. An explosion-proof valve protection plate 58 is provided on the explosion-proof valve 57.

[0052] In summary, the battery cell provided by this utility model has at least the following advantages:

[0053] (1) The first end of the separator 4 is located between the first insulating member 52 and the cover plate 51 to achieve sealing and fixation. This arrangement of the separator 4 does not impose very strict requirements on the height of the first insulating member 52, thereby reducing the height of the first insulating member 52 and correspondingly reducing the maximum height of the cover plate assembly 5. With the same size housing 2, after the maximum height of the cover plate assembly 5 is reduced, the maximum height of the electrode group 1 can be set to be larger, and the corresponding cell capacity is larger.

[0054] (2) A portion of the tab 11 is located between the adapter piece 55 and the first insulator 52, constraining each set of tabs 11 through the adapter piece 55 and the first insulator 52. Since each set of tabs 11 is constrained by the adapter piece 55 and the first insulator 52, the tabs 11 are in a clamped and constrained state. Therefore, the space occupied by the tabs 11 is smaller, the maximum depth required for the receiving groove 521 is reduced, that is, the maximum height of the first insulator 52 can be reduced, and the overall height of the corresponding cover assembly 5 is lower. With the same housing size, the lower the overall height of the cover assembly 5, the greater the maximum height that the electrode group 1 can be set, and the larger the corresponding cell capacity.

[0055] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A cover plate assembly electrically connected to the electrode tabs of an electrode group, characterized in that, include: Cover plate; The first insulating element is located on one side of the cover plate, and a receiving groove is formed on one side of it; The pole post protrudes after passing through the first insulator and the cover plate from the side of the first insulator away from the cover plate; An adapter piece is located within the receiving groove and is electrically connected to the pole and the tab, with a portion of the tab located between the adapter piece and the first insulating member.

2. The cover plate assembly according to claim 1, characterized in that, The cover plate assembly further includes a snap-fit ​​member, which is fixed to the side of the first insulating member away from the cover plate. A snap-fit ​​groove is formed between the snap-fit ​​member and the first insulating member, and a portion of the adapter piece is accommodated in the snap-fit ​​groove to constrain the adapter piece.

3. The cover plate assembly according to claim 2, characterized in that, The snap-fit ​​component and the first insulating component are made of plastic, and the snap-fit ​​component and the first insulating component are ultrasonically welded together.

4. The cover plate assembly according to claim 1, characterized in that, The adapter includes an integrally connected pole contact portion and a tab contact portion. The pole contact portion contacts the pole to achieve electrical connection, and the tab contact portion contacts the tab to achieve electrical connection.

5. The cover plate assembly according to claim 4, characterized in that, The electrode contact portion includes two parts, both located on the same side of the electrode contact portion, and each electrode contact portion is in contact with at least one set of electrodes.

6. The cover plate assembly according to claim 4, characterized in that, The corners of the electrode contact portion are rounded.

7. The cover plate assembly according to claim 1, characterized in that, The cover plate assembly also includes an explosion-proof valve, which is installed on the cover plate and corresponds to the vent hole provided on the cover plate. The first insulating member is provided with a vent port corresponding to the explosion-proof valve.

8. A battery cell, characterized in that, The device includes an electrode assembly and a cover plate assembly as described in any one of claims 1 to 7, wherein the electrode assembly includes an electrode tab, a portion of which is located between the adapter plate and the cover plate.

9. The battery cell according to claim 8, characterized in that, The battery cell also includes: The housing contains the electrode assembly, and the cover plate assembly is located at one end of the housing; An isolation membrane is located between the housing and the electrode assembly, with one end located between the cover plate and the first insulating member.

10. The battery cell according to claim 9, characterized in that, The housing is square, and the positive and negative tabs of the electrode group are located at the same end of the electrode group near the cover plate assembly. The adapter includes a positive adapter that is electrically connected to the positive tab and a negative adapter that is electrically connected to the negative tab.

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