Negative electrode terminal assembly for battery cell top cover and battery cell top cover assembly

Abstract

The utility model belongs to the technical field of energy storage devices, and particularly relates to a negative electrode terminal assembly for a battery cell top cover and a battery cell top cover assembly comprising the electrode terminal assembly, the negative electrode terminal assembly for the battery cell top cover is arranged on an electrode leading-out hole of a cover plate, and the electrode leading-out hole is formed in the cover plate. Comprising an insulating part, a battery cell negative pole and a sealing part, according to the negative electrode terminal assembly for the battery cell top cover, the number of parts in the assembly is small, the structure of a cell cover plate assembly is simplified, the space utilization rate of a lithium cell is improved, and the energy density of the cell is further improved; and due to the reduction of parts and interfaces, failure points are effectively reduced, so that the yield of the battery cell is improved, the failure probability of the battery cell is reduced, and the reliability of a battery system is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy storage devices, and particularly relates to a negative electrode terminal assembly for a battery cell top cover, and a battery cell top cover assembly including the electrode terminal assembly. Background Art

[0002] The structural components of new energy batteries are continuously iterated. It includes a cell top cover and a housing, which are the core components for protecting the safety of lithium batteries, playing roles such as supporting, protecting, and transmitting energy. It needs to have characteristics such as high dimensional accuracy, high surface quality, and high performance requirements, playing roles such as transmitting energy, carrying electrolyte, protecting safety, and fixing and supporting the battery, and having specific functions such as connectability, seismic resistance, heat dissipation, corrosion resistance, anti-interference, and antistatic according to different application environments.

[0003] The structure of the lithium battery top cover is complex and precise, undertaking the functions of energy transmission and explosion-proof pressure relief, and is composed of more than 10 kinds of components. The existing top cover structure mainly consists of structures such as a cover plate, positive and negative electrode posts, liquid injection holes, flip pieces, explosion-proof sheets (valves), etc. For example, a top cover assembly of a secondary battery disclosed in Chinese patent document CN109817853A has a complex and precise structure, numerous components and interfaces, resulting in many overall failure points of the battery cell, low yield, high production cost, and short top cover life. Summary of the Utility Model

[0004] Aiming at the deficiencies in the prior art, the purpose of the utility model is to provide a highly integrated negative electrode terminal assembly for a battery cell top cover, and a battery cell top cover assembly including the electrode terminal assembly, so as to solve the technical problems such as low yield and short top cover life caused by too many components in the existing top cover structure.

[0005] To achieve the above purpose, the solutions adopted by the utility model are as follows:

[0006] In the first aspect, the utility model provides a negative electrode terminal assembly for a battery cell top cover, which is arranged on the electrode lead-out hole of the cover plate. Among them, the negative electrode terminal assembly for a battery cell top cover includes:

[0007] An insulating member, including a base and a convex platform located on the base. The base is stuck on one side of the cover plate, the convex platform penetrates through the electrode lead-out hole of the cover plate and extends towards the other side of the cover plate. The base and the convex platform have a through stepped hole, and the large-sized hole of the stepped hole is located on the side of the convex platform;

[0008] The negative electrode terminal of the battery cell includes a negative electrode terminal plate of the battery cell and a negative electrode terminal lining connected to one side of the negative electrode terminal plate of the battery cell. The negative electrode terminal plate of the battery cell covers the large-diameter hole of the stepped hole of the insulating member. The negative electrode terminal lining of the battery cell includes a press riveting and fixing portion passing through the stepped hole of the insulating member and a connecting column provided at the top for connecting to the negative electrode terminal plate of the battery cell;

[0009] The sealing member is located in the annular space between the side wall of the negative electrode terminal lining of the battery cell and the inner wall of the stepped hole of the insulating member.

[0010] Preferably, the insulating member is made of plastic and is integrally injection-molded on the electrode lead-out hole of the cover plate.

[0011] Preferably, the material of the negative electrode terminal of the battery cell is selected from any one of silver, copper, gold, aluminum, nickel, and iron, and preferably aluminum.

[0012] In a second aspect, the present utility model further provides a battery cell top cover assembly, which includes a cover plate provided with an electrode lead-out hole, and further includes the negative electrode terminal assembly for the top cover of the battery cell as described above installed in the electrode lead-out hole of the cover plate.

[0013] Preferably, a pressure relief hole and a liquid injection hole are further provided on the cover plate, and the liquid injection hole is located beside the pressure relief hole.

[0014] Preferably, a pressure relief member is further installed in the pressure relief hole for relieving the internal pressure of the battery when the internal pressure or temperature of the battery reaches a threshold value.

[0015] Preferably, the pressure relief member includes an explosion-proof sheet covering the pressure relief hole of the cover plate and a dust-proof cover plate covering the explosion-proof sheet.

[0016] Preferably, a core positioning block is further included. The core positioning block is located on the side of the cover plate facing the battery core, and the top of the battery core abuts against the core positioning block; the core positioning block is two plastic parts, which are respectively arranged on one side of the electrode lead-out hole of the cover plate and at the pressure relief hole, and are integrally injection-molded on the cover plate with the insulating member in the negative electrode terminal assembly for the top cover of the battery cell.

[0017] Advantageous Effects

[0018] The negative electrode terminal assembly for the top cover of the battery cell provided by the present utility model has fewer components in the assembly, simplifies the structure of the battery cell cover assembly, improves the space utilization rate of the lithium battery cell, and further improves the energy density of the battery cell; due to the reduction of components and interfaces, the failure points are effectively reduced, thereby improving the yield rate of the battery cell, reducing the probability of battery cell failure, and ensuring the reliability of the battery system. Description of the Drawings

[0019] Figure 1 Schematic three-dimensional structure diagram of the battery cell top cover assembly related to the present utility model.

[0020] Figure 2 Schematic three-dimensional exploded structure diagram of the battery cell top cover assembly related to the present utility model.

[0021] Figure 3 For Figure 1 Schematic three-dimensional structure diagram of the back surface of the assembled battery cell top cover assembly before riveting in

[0022] Figure 4 For Figure 1 Schematic three-dimensional structure diagram of the back surface of the assembled battery cell top cover assembly after riveting in

[0023] Figure 5 For Figure 1 Schematic plan structure diagram of the back surface of the assembled battery cell top cover assembly before riveting in

[0024] Figure 6 For Figure 1 Schematic plan structure diagram of the back surface of the assembled battery cell top cover assembly after riveting in

[0025] Figure 7 Cross-sectional view of the assembled battery cell top cover assembly related to the present utility model.

[0026] Figure 8 Schematic structure diagram of the cover plate in the negative electrode terminal assembly for the battery cell top cover related to the present utility model.

[0027] Figure 9 Schematic structure diagram of the insulating part in the negative electrode terminal assembly for the battery cell top cover related to the present utility model.

[0028] Figure 10 Schematic structure diagram of the seal in the negative electrode terminal assembly for the battery cell top cover related to the present utility model.

[0029] Figure 11 Schematic structure diagram of the cell negative electrode plate in the negative electrode terminal assembly for the battery cell top cover related to the present utility model.

[0030] Figure 12 Schematic structure diagram of the cell negative electrode inner lining in the negative electrode terminal assembly for the battery cell top cover related to the present utility model.

[0031] Figure 13 Schematic structure diagram of the explosion-proof film of the battery cell top cover assembly related to the present utility model.

[0032] Figure 14Schematic diagram of the dust-proof cover of the battery cell top cover assembly related to the present utility model.

[0033] In the figure,

[0034] 1 - Electrode terminal assembly, 11 - Insulating part, 111 - Base, 112 - Boss, 113 - Step hole, 12 - Negative electrode column of the battery cell, 121 - Plate of the negative electrode column of the battery cell, 122 - Liner of the negative electrode column of the battery cell, 122a - Riveting fixing part, 13 - Sealing part

[0035] 2 - Cover plate, 21 - Electrode lead-out hole, 22 - Pressure relief hole, 23 - Liquid injection hole

[0036] 3 - Pressure relief part, 31 - Explosion-proof film, 32 - Dust-proof cover plate

[0037] 4 - Core positioning block. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts fall within the scope of protection of the present utility model.

[0040] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship when the product of this utility model is usually placed. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0042] In addition, terms such as "horizontal" and "vertical" do not require the components to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the present invention, it should also be noted that, unless otherwise clearly specified and defined, the terms "arranged", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] For this reason, the following solutions are proposed:

[0045] <Electrode terminal assembly>

[0046] See Figures 1 to 14 , the present invention provides a negative electrode terminal assembly 1 for the top cover of a battery cell, which is arranged on the electrode lead-out hole 21 of the cover plate 2. Among them, the negative electrode terminal assembly 1 for the top cover of the battery cell includes: an insulating member 11, a battery cell negative electrode post 12, and a sealing member 13.

[0047] Specifically, in combination with Figure 1 , Figure 2 , Figure 7 and Figure 9 shown, in the negative electrode terminal assembly 1 for the top cover of a battery cell provided by the present invention, the insulating member 11, made of plastic, is integrally injection-molded on the electrode lead-out hole 21 of the cover plate 2, and includes a base 111 and a boss 112 located on the base 111. The base 111 is stuck on one side of the cover plate 2 (i.e., Figure 1 and Figure 2 the back of the cover plate 2 in Figure 1 and Figure 2 ), the boss 112 penetrates through the electrode lead-out hole 21 of the cover plate 2 and extends towards the other side of the cover plate 2 (i.e., Figure 1 and Figure 2 the front of the cover plate 2 in Figure 1 and Figure 2 ), and the base 111 and the boss 112 have a through stepped hole 113, and the large-size hole of the stepped hole 113 is located on the side of the boss 112.

[0048] In combination with Figure 1 , Figure 2 , Figure 7 , Figure 11 and Figure 12As shown in the figure, in a negative electrode terminal assembly 1 for a battery cell top cover provided by the present utility model, the cell negative electrode post 12 includes a cell negative electrode post plate 121 and a cell negative electrode post lining 122 connected to one side of the cell negative electrode post plate 121.

[0049] Here, the cell negative electrode post plate 121 and the cell negative electrode post lining 122 are of a split structure. The cell negative electrode post plate 121 is integrally flat and can cover the large-diameter hole of the stepped hole 113 of the insulating part 11. The cell negative electrode post lining 122 includes a press riveting and fixing part 122a passing through the stepped hole 113 of the insulating part 11 and a connecting post formed at the top. The cell negative electrode post lining 122 with such a structure forms support and connection to the cell negative electrode post plate 121 through the connecting post at the top, improving the reliability of the connection. At the same time, through the press riveting and fixing part 122a passing through the stepped hole 113 of the insulating part 11 and extending to the back of the cover plate 2 (as Figure 3 shown), and through riveting deformation, a riveting and fixing structure is formed with the back of the cover plate 2 (as Figure 4 shown), thereby realizing the fixed setting between the cell negative electrode post 12 and the cover plate 2.

[0050] Here, the specific number and shape of the connecting posts on the cell negative electrode post lining 122 are not limited. Preferably, two cylindrical connecting posts are formed on the cell negative electrode post lining 122.

[0051] In some embodiments, the material of the cell negative electrode post plate 121 of the cell negative electrode post 12 is selected from any one of silver, copper, gold, aluminum, nickel, and iron, and preferably aluminum.

[0052] In some embodiments, the material of the cell negative electrode post lining 122 of the cell negative electrode post 12 is selected from any one of silver, copper, gold, aluminum, nickel, and iron, and preferably copper.

[0053] As an embodiment of the present utility model, the connection method between the cell negative electrode post plate 121 and the cell negative electrode post lining 122 includes any one of, for example, riveting, ultrasonic welding, and explosion welding.

[0054] Combined with Figure 1 、 Figure 2 、 Figure 7 and Figure 10 shown, in a negative electrode terminal assembly 1 for a battery cell top cover provided by the present utility model, the sealing part 13 is located in the annular space between the side wall of the cell negative electrode post lining 122 of the cell negative electrode post 12 and the inner wall of the stepped hole 113 of the insulating part 11, sleeved around the cell negative electrode post lining 122 of the cell negative electrode post 12, and is used to seal the gap between the cell negative electrode post 12 and the insulating part 11, thereby ensuring the sealing performance of the battery cell top cover.

[0055] During the assembly process, first, electrode lead holes 21 are made on the cover plate 2 with the structure as shown in Figure 8 . Then, an insulating part 11 with the structure as shown in Figure 9 is integrally injection-molded on the electrode lead holes 21. Any one of the methods such as riveting, ultrasonic welding, and explosion welding is used to weld the inner lining 122 of the negative electrode column of the battery cell with the structure as shown in Figure 12 to the negative electrode column plate 121 of the battery cell with the structure as shown in Figure 11 to form the negative electrode column 12 of the battery cell. Then, a seal 13 with the structure as shown in Figure 10 is sleeved on the outer periphery of the inner lining 122 of the negative electrode column of the battery cell. Then, the negative electrode column 12 of the battery cell is covered in the stepped hole 113 of the insulating part 11 in the direction as shown in Figure 2 , and the seal 13 located on the outer periphery of the inner lining 122 of the negative electrode column of the battery cell is fixed on the inner wall of the stepped hole 113 of the insulating part 11. The riveting fixing part 122a of the inner lining 122 of the negative electrode column of the battery cell of the negative electrode column 12 extends out of the back surface of the cover plate 2, forming a three-dimensional structure schematic diagram of the back surface of the assembled battery cell top cover assembly before riveting as shown in Figure 3 . After the riveting fixing part 122a of the inner lining 122 of the negative electrode column of the battery cell of the negative electrode column 12 is riveted and fixed, a three-dimensional structure schematic diagram of the back surface of the assembled battery cell top cover assembly after riveting as shown in Figure 4 is formed. During the riveting process, since the riveting fixing part 122a of the inner lining 122 of the negative electrode column of the battery cell of the negative electrode column 12 squeezes towards the inner wall of the stepped hole 113 of the insulating part 11, the seal 13 between the side wall of the inner lining 122 of the negative electrode column of the battery cell of the negative electrode column 12 and the inner wall of the stepped hole 113 of the insulating part 11 is further squeezed, further improving the sealing performance between the negative electrode column 12 of the battery cell and the insulating part 11. Figure 5 and Figure 6 are respectively the planar structure schematic diagrams of the back surfaces of the respective components of the battery cell top cover assembly in Figure 1 before and after riveting after assembly.

[0056] A negative electrode terminal assembly for a battery cell top cover provided by the present utility model, compared with the existing electrode terminal assembly, has fewer components in the assembly, simplifies the structure of the battery cell cover assembly, improves the space utilization rate of the lithium battery cell, and further improves the energy density of the battery cell; due to the reduction of components and interfaces, the failure points are effectively reduced, thereby improving the yield rate of the battery cell, reducing the probability of battery cell failure, and ensuring the reliability of the battery system.

[0057] <Battery cell top cover assembly>

[0058] See Figure 1 , Figure 2, the present utility model further provides a battery cell top cover assembly, including a cover plate 2 and an electrode terminal assembly 1. An electrode lead-out hole 21 is provided on the cover plate 2, and the electrode terminal assembly 1 is installed in the electrode lead-out hole 21 of the cover plate 2. Combining Figure 8 As shown, a pressure relief hole 22 and a liquid injection hole 23 are further provided on the cover plate 2. A pressure relief member 3 is provided on the pressure relief hole 22. The pressure relief member 3 includes an explosion-proof film 31 covering the pressure relief hole 22 of the cover plate 2 (as Figure 13 shown) and a dust-proof cover plate 32 covering the explosion-proof film 31 (as Figure 14 shown).

[0059] In a battery cell top cover assembly provided by the present utility model, a core positioning block 4 is further included. The core positioning block 4 is located on the side of the cover plate 2 facing the core, and the top of the battery core abuts against the core positioning block 4. The core positioning block 4 is two plastic parts, which are respectively arranged on one side of the electrode lead-out hole 21 of the cover plate 2 and at the pressure relief hole 22, and are integrally injection-molded on the cover plate 2 with the insulating part 11 in the electrode terminal assembly 1.

[0060] <Battery cell and battery pack>

[0061] According to the prior art, a battery cell for forming a battery pack of a new energy vehicle usually includes a top cover assembly, a housing, and an electrode assembly. In the present utility model, the top cover assembly of this battery cell adopts the above-mentioned battery cell top cover assembly provided by the present utility model. The electrode lead of the positive electrode plate or the negative electrode plate in the electrode assembly is connected to the inner lining 122 of the battery cell negative electrode column of the electrode terminal assembly 1 on the electrode lead-out hole 21 of the cover plate 2 of the above-mentioned battery cell top cover assembly provided by the present utility model. The battery cell negative electrode column plate 121 of the electrode terminal assembly 1 on the above-mentioned battery cell top cover assembly provided by the present utility model is connected to an external power source, so as to energize the battery cell. During assembly or use, the (supplemental) electrolyte can be injected through the liquid injection hole 23 located on the cover plate 2 in the above-mentioned battery cell top cover assembly provided by the present utility model.

[0062] In a battery cell top cover assembly provided by the present utility model, the pressure relief member 3 located on the pressure relief hole 22 of the cover plate 2 is used to release the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold value. The explosion-proof film 31 of the pressure relief member 3 can also be an explosion-proof valve, a gas valve, a pressure relief valve, a safety valve, etc.

Claims

1. A negative electrode terminal assembly for a battery cell top cover, arranged on the electrode lead-out hole of the cover plate, characterized in that: The negative electrode terminal assembly for the battery cell top cover comprises: An insulating member, comprising a base and a boss located on the base, wherein the base is clamped on one side of the cover plate, the boss passes through the electrode lead-out hole of the cover plate and extends toward the other side of the cover plate, the base and the boss have a penetrating step hole, and the large-size hole of the step hole is located on one side of the boss; A battery cell negative electrode column, comprising a battery cell negative electrode column plate and a battery cell negative electrode column liner connected to one side of the battery cell negative electrode column plate, wherein the battery cell negative electrode column plate covers the large-sized hole of the step hole of the insulating member, and the battery cell negative electrode column liner comprises a riveted fixing portion passing through the step hole of the insulating member and a connecting column arranged at the top for connecting to the battery cell negative electrode column plate; The sealing member is located in the annular space between the side wall of the inner liner of the negative electrode column of the battery cell and the inner wall of the step hole of the insulating member.

2. The negative electrode terminal assembly for a battery cell top cover according to claim 1, characterized in that: The insulating member is made of plastic and is integrally injection-molded on the electrode lead-out hole of the cover plate.

3. The negative electrode terminal assembly for a battery cell top cover according to claim 1, characterized in that: The material of the negative electrode column plate of the negative electrode column of the battery cell is selected from any one of silver, copper, gold, aluminum, nickel and iron.

4. The negative electrode terminal assembly for a battery cell top cover according to claim 1, characterized in that: The material of the inner lining of the negative electrode column of the battery cell is selected from any one of silver, copper, gold, aluminum, nickel and iron.

5. The negative electrode terminal assembly for a battery cell top cover according to claim 1, characterized in that: The connection method of the battery cell negative electrode column plate and the battery cell negative electrode column liner is selected from any one of riveting, ultrasonic welding and explosion welding.

6. A battery cell top cover assembly, comprising a cover plate provided with an electrode lead-out hole, characterized in that: It also includes a negative electrode terminal assembly for a battery cell top cover as described in any one of claims 1 to 5, which is installed in the electrode lead-out hole of the cover plate.

7. The battery cell top cover assembly according to claim 6, characterized in that: The cover plate is also provided with a pressure relief hole and a liquid injection hole, and the liquid injection hole is located beside the pressure relief hole.

8. The battery cell top cover assembly according to claim 7, characterized in that: Also included is a pressure relief member installed in the pressure relief hole, for releasing the pressure inside the battery when the internal pressure or temperature of the battery reaches a threshold value.

9. The battery cell top cover assembly according to claim 8, characterized in that: The pressure relief component comprises an explosion-proof plate covering the pressure relief hole of the cover plate and a dust-proof cover plate covering the explosion-proof plate.

10. The battery cell top cover assembly according to claim 7, characterized in that: It also includes a core positioning block, which is located on the side of the cover plate facing the core, and the top of the battery core rests on the core positioning block; the core positioning block is two plastic parts, which are respectively arranged on one side of the electrode lead-out hole of the cover plate and at the pressure relief hole, and are integrally injection-molded on the cover plate with the insulating part in the negative electrode terminal assembly for the battery cell top cover.

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