WO2024000946A1 - Cap assembly, battery, battery module, battery pack, and vehicle - Google Patents

Abstract

Provided in the present application are a cap assembly, a battery, a battery module, a battery pack, and a vehicle. The cap assembly is used for a battery, the battery comprising a cell and a casing used for accommodating the cell. The cap assembly comprises a disc busbar and a plastic pad; the disc busbar is arranged in the casing, and the disc busbar is attached to the top end of the cell so as to be connected to the cell; and the plastic pad is located between the casing and the disc busbar, and the surface of the plastic pad is arranged in a raised-and-recessed mode.

Description

Cap components, batteries, battery modules, battery packs and vehicles

This application claims priority to the Chinese patent application with application number 202221649841.1, which was submitted to the China Patent Office on June 28, 2022. The entire content of the above application is incorporated into this application by reference.

Technical field

The present application relates to the field of battery technology, for example, to a cap assembly, a battery, a battery module, a battery pack and a vehicle.

Background technique

Batteries are widely used in life. Batteries in related technologies mainly include battery cells, battery casings and cap components. That is, the battery cells are placed into the battery casing and the tabs of the battery cells are bent together and then connected to the cap component, thereby achieving The cap assembly is electrically connected to the battery core and the battery case is sealed. During the process of assembling the battery, plastic pads are often used to protect and seal the cells. Since the plastic pads will swell after contact with the electrolyte in the battery case, the rubber pads will cause greater damage to the case and cells. Under large pressure, the casing and battery core may easily deform after long-term use of the battery, thereby affecting the performance of the battery.

Contents of the invention

This application provides a cap assembly, which is provided with concavities and convexities on the surface of the plastic pad, thereby absorbing the stress generated by the plastic pad when it swells, reducing the pressure of the stress on the battery core and the casing, and also absorbing the pressure generated by the expansion of the battery core due to charging. .

In a first aspect, the application provides a cap assembly for a battery. The battery includes a battery core and a shell for accommodating the battery core. The cap assembly includes:

A busbar, the busbar is arranged in the housing, and the busbar is attached to the top of the battery core to connect with the battery core;

A plastic pad is located between the housing and the manifold, and the surface of the plastic pad is concave and convex.

In one embodiment, a plurality of first annular grooves are provided on the top surface of the plastic pad, and the plurality of first annular grooves are equidistantly distributed along the radial direction of the plastic pad.

In one embodiment, a plurality of second annular grooves are provided on the bottom surface of the plastic pad, and the plurality of second annular grooves are equidistantly distributed along the radial direction of the plastic pad.

In one embodiment, the first annular grooves and the second annular grooves are staggered.

In one embodiment, the cap assembly further includes:

Terminals, the terminals are inserted through the top of the housing and are electrically connected to the busbar;

A sealing ring is located between the housing and the terminal, and the sealing ring penetrates the plastic pad.

In one embodiment, the cap assembly further includes a cover plate, which is disposed at the bottom end of the housing and connected to the battery core.

This application provides a battery. By applying the above-mentioned cap assembly, the stress generated by the swelling of the plastic pad and the pressure generated by the expansion of the battery core due to charging can be absorbed, thereby ensuring the performance of the battery.

In a second aspect, the present application provides a battery. The battery includes a battery core, a casing and a cap assembly as described above. The casing is used to accommodate the battery core, and the cap assembly is connected to the battery cell respectively. The core is connected to the shell.

This application provides a battery module. By using the above-mentioned battery, it can absorb the stress generated by the swelling of the plastic pad and the pressure generated by the expansion of the battery core due to charging, thereby ensuring the performance of the battery.

In a third aspect, the present application provides a battery module. The battery module includes a plurality of batteries as described above, and a plurality of the batteries are arranged in multiple rows and columns.

This application provides a battery pack that can absorb the stress generated by the swelling of the plastic pad and the pressure generated by the expansion of the battery core due to charging by applying the above-mentioned battery module, thereby ensuring the performance of the battery.

In a fourth aspect, the present application provides a battery pack, including a box and the above-mentioned battery module, and the battery module is arranged in the box.

This application provides a vehicle that can absorb the stress generated by the swelling of the plastic pad and the pressure generated by the expansion of the battery core due to charging by applying the above-mentioned battery pack, thereby ensuring the performance of the battery.

In a fifth aspect, the present application provides a vehicle, including a vehicle body and a battery pack as described above, and the battery pack is disposed in the vehicle body.

The beneficial effects of this application are:

This application provides a cap assembly, battery, battery module, battery pack and vehicle. The surface of the plastic pad is concave and convex, thereby absorbing the stress generated by the plastic pad when it swells, reducing the pressure of the stress on the battery core and the casing, and also It can absorb the pressure caused by the expansion of battery cells due to charging. The application has a simple structure, is easy to disassemble and assemble, and can absorb the stress generated by the swelling of the plastic pad and the pressure generated by the expansion of the battery core due to charging, thereby ensuring the performance of the battery.

Description of drawings

Figure 1 is a schematic structural diagram of a battery module provided by an exemplary embodiment of the present application;

Figure 2 is a schematic structural diagram of a battery provided by an exemplary embodiment of the present application;

Figure 3 is a schematic structural diagram of the battery in an exploded state according to the exemplary embodiment of the present application;

Figure 4 is a cross-sectional view of a battery provided by an example embodiment of the present application;

Figure 5 is a partial enlarged structural diagram of position A in Figure 4;

Figure 6 is a partial enlarged structural diagram of B in Figure 4;

Figure 7 is a bottom view of a battery provided by an exemplary embodiment of the present application;

Figure 8 is a schematic cross-sectional structural diagram along the C-C direction in Figure 7;

Figure 9 is a partial enlarged structural diagram of D in Figure 8;

Figure 10 is a bottom view of another battery provided by an example embodiment of the present application;

Figure 11 is a schematic cross-sectional structural diagram along the E-E direction in Figure 10;

Figure 12 is a partial enlarged structural diagram of F in Figure 11.

Reference signs:

1. Battery;

11. Cap assembly; 111. Cover plate; 1111. Welding part; 1112. Explosion-proof valve; 11121. Explosion-proof notch; 1113. Limiting part; 1114. Liquid injection hole; 112. Manifold; 113. Terminal; 114. Suction Energy structure; 1141, sealing ring; 1142, plastic gasket; 11421, first annular groove; 11422, second annular groove; 11423, isolation part;

12. Shell;

13. Battery core; 131. Positive pole tab; 132. Negative pole tab;

14. Solder part; 15. Solder bead part and lug;

14. Solder part; 15. Welding bead part.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.

In the description of this application, unless otherwise explicitly stipulated and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body. ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood on a case-by-case basis.

In this application, unless otherwise explicitly stated and limited, the term "above" or "below" a first feature on a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above or diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

It should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis", "Radial", " The orientation or positional relationship indicated such as "circumferential direction" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation. Constructed and operated in a specific orientation and therefore should not be construed as limiting this application. In the description of this application, unless otherwise stated, "plurality" means two or more. In addition, the terms "first" and "second" are only used for descriptive purposes and have no special meaning. Among them, the terms "first position" and "second position" are two different positions.

The technical solution of the present application will be described below with reference to the accompanying drawings and through example implementations.

This embodiment provides a vehicle, which includes a vehicle body and a battery pack. The battery pack is arranged in the vehicle body, and the battery pack provides power to the vehicle body to drive the vehicle body to move. The battery pack includes a box and a battery module. The battery module is arranged in the box, that is, the battery module is fixed and protected through the box. For example, as shown in Figure 1, in order to maximize the maximum amount of electricity that can be stored by the entire battery module, the battery module includes multiple batteries 1, and the multiple batteries 1 are arranged in multiple rows and columns. The number and specific arrangement of batteries 1 can be adjusted according to actual conditions, and are not specifically limited in this embodiment.

As shown in Figure 2, Figure 3 and Figure 4, the battery includes a battery core 13, a casing 12 and a cap assembly 11. The casing 12 is used to accommodate the battery core 13. The cap assembly 11 is connected to the battery core 13 and the casing 12 respectively. The cap assembly 11 includes a cover plate 111, a bus plate 112 and a terminal 113. The cover plate 111 is arranged at the bottom end of the housing 12 and is connected to the negative electrode tab 132 of the battery core 13. The bus plate 112 is attached to the top of the battery core 13. Connected to the positive tab 131 of the battery core 13 , the terminal 113 is passed through the top of the housing 12 and electrically connected to the bus plate 112 , and there is a gap between the top of the bus plate 112 and the bottom of the terminal 113 .

The cap assembly 11 in this embodiment creates a gap between the bus plate 112 and the terminal 113 to avoid friction and collision during assembly and use, ensuring the working performance and service life of the battery 1 as much as possible, and also ensuring the battery 1 as long as possible. The number of parts required for the cap assembly 11 is reduced, manufacturing costs are saved, and disassembly and assembly procedures are reduced. The cap assembly 11 can avoid friction and collision during assembly and use, ensure the working performance and service life of the battery 1 as much as possible, and can also reduce the number of parts required for the cap assembly 11 as much as possible, saving manufacturing costs, and The disassembly and assembly process is reduced.

In this embodiment, as shown in FIG. 4 and FIG. 5 , the cap assembly 11 also includes an energy-absorbing structure 114 . The energy-absorbing structure 114 is connected to the terminal 113 , the housing 12 and the manifold 112 respectively, and the energy-absorbing structure 114 is configured as A gap can be provided between the top end of the bus plate 112 and the bottom end of the terminal 113 . In addition, the energy-absorbing structure 114 can also play a certain shock-absorbing and buffering role between the terminal 113, the housing 12, and the busbar 112, thereby enhancing the ability of the battery 1 to withstand vibration and impact, and extending the service life of the entire battery 1. .

Exemplarily, the energy-absorbing structure 114 includes a sealing ring 1141 and a plastic gasket 1142. The sealing ring 1141 is located between the housing 12 and the terminal 113. The plastic gasket 1142 is located between the housing 12 and the manifold 112, and the sealing ring 1141 passes through On the plastic pad 1142. By providing the sealing ring 1141, the sealing between the terminal 113 and the housing 12 can also be achieved, thereby ensuring the safety of the cap assembly 11. And through the cooperation of the sealing ring 1141 and the plastic gasket 1142, a gap exists between the top end of the bus plate 112 and the bottom end of the terminal 113. For example, the material of the sealing ring 1141 may be electrolyte-resistant rubber or elastic plastic.

In this embodiment, the surface of the plastic pad 1142 is concave and convex to absorb the stress generated by the plastic pad 1142 when it swells, reduce the pressure of the stress on the battery core 13 and the housing 12, and also absorb the stress caused by the expansion of the battery core 13 due to charging. pressure.

Exemplarily, a plurality of first annular grooves 11421 are provided on the top surface of the plastic pad 1142. The plurality of first annular grooves 11421 are equidistantly distributed in the radial direction to improve the shock absorption and buffering effect of the entire energy-absorbing structure 114. Similarly, a plurality of second annular grooves 11422 are provided on the bottom surface of the plastic pad 1142, and the plurality of second annular grooves 11422 are equidistantly distributed in the radial direction. The plastic pad 1142 will swell in the electrolyte of the battery 1. The first annular groove 11421 and the second annular groove 11422 can absorb the stress generated by the plastic pad 1142 when it swells and reduce the stress on the battery core 13 and the case. 12. In addition, when the battery core 13 is expanded due to charging, the first annular groove 11421 and the second annular groove 11422 can also absorb the expansion pressure of the battery core 13.

For example, the first annular groove 11421 and the second annular groove 11422 are staggered, so that the surface of the plastic pad 1142 is uneven to enhance the shock-absorbing and buffering effect of the entire plastic pad 1142.

In this embodiment, the edge of the plastic pad 1142 extends in the direction close to the manifold 112 to form an isolation part 11423. The plastic pad 1142 can be covered on the manifold 112 through the isolation part 11423. The side of the isolation part 11423 away from the manifold 112 is in contact with the shell. The inner wall of the body 12 is close to each other, that is, the side peripheral wall of the manifold plate 112 is separated from the inner wall of the case 12 through the isolation portion 11423, thereby avoiding direct contact between the manifold plate 112 and the case 12 and improving the voltage resistance of the entire battery 1. Illustratively, manifold 112 is made of aluminum.

Among them, as shown in Figures 6 to 12, the cover plate 111 is provided with a welding portion 1111 and an explosion-proof valve 1112. The welding portion 1111 protrudes relative to the cover plate 111 in a direction close to the battery core 13. The explosion-proof valve 1112 is located relative to the cover plate. 111 protrudes in a direction away from the battery core 13 , that is, the welding portion 1111 is welded to the negative electrode tab 132 of the battery core 13 , and the explosion-proof valve 1112 serves as an explosion-proof function for the battery core 13 . In addition, since the welding portion 1111 protrudes in a direction closer to the battery core 13 relative to the cover plate 111 , the explosion-proof valve 1112 protrudes in a direction away from the battery core 13 relative to the cover plate 111 , that is, the top surface of the cover plate 111 is in contact with the negative electrode tab. The bottom surface of 132 has a distance h1, and the bottom surface of the explosion-proof valve 1112 and the bottom surface of the negative electrode tab 132 have a distance h2, so it can be seen that h2>h1>0, so h1 can be used to absorb the force generated when the battery core 13 expands, h2 and h1 The height difference between them can be used to collect blasting gas, ensuring a stable connection between the cover plate 111 and the negative electrode tab 132 while preventing the battery 1 from spontaneous combustion or explosion due to excessive internal pressure, thereby improving the safety of the battery 1 .

For example, the maximum width of the explosion-proof valve 1112 is less than half the radius of the housing 12 to minimize the exhaust space required for the entire battery module.

For example, the explosion-proof valve 1112 is provided with an explosion-proof score 11121, and the explosion-proof score 11121 is formed by stamping, so that when the internal pressure of the battery 1 is too high, the gas in the casing 12 can be released along the explosion-proof score 11121, reducing The gas release causes damage to the surroundings of the battery 1 .

For example, multiple welding portions 1111 are provided, and the plurality of welding portions 1111 are arranged in a ring on the cover plate 111 to ensure the stability of the connection with the negative electrode tab 132 . By way of example, three welding parts 1111 are provided.

For example, the welding part 1111 is arc-shaped, and the maximum optimal arc length of the welding part 1111 is greater than half the radius of the battery core 13 to ensure the largest contact area between the battery core 13 and the cover 111 as much as possible, and improve the electrical connection between the two. stability. Of course, in other embodiments, the welding portion 1111 can also have other shapes, as long as the welding portion 1111 and the negative electrode tab 132 can be welded stably, this embodiment does not impose any specific restrictions.

For example, multiple explosion-proof valves 1112 are provided, and the multiple explosion-proof valves 1112 are respectively arranged around the cover plate 111 to improve the explosion-proof performance. By way of example, three explosion-proof valves 1112 are provided.

For example, the welded portions 1111 and the explosion-proof valves 1112 are staggered to ensure balanced force on the entire cover 111 and improve gas circulation in the housing 12 .

In other embodiments, as shown in FIG. 10 , the cover plate 111 is also provided with a liquid injection hole 1114 for liquid injection or exhaust.

For example, the liquid injection hole 1114 coincides with the axis of the battery core 13 , that is, the liquid injection hole 1114 is provided in the center of the cover plate 111 to ensure balanced force on the entire cover plate 111 .

For example, the cover plate 111 protrudes along the edge of the liquid injection hole 1114 in a direction closer to the battery core 13 to form a liquid injection boss, thereby increasing the structural strength of the middle part of the cover plate 111 .

In this embodiment, as shown in FIGS. 7 to 9 , a limiting portion 1113 is also provided at the outer peripheral edge of the cover 111 . The limiting portion 1113 protrudes toward the battery core 13 relative to the cover 111 to surround the negative electrode. The lug 132, that is, positioning the negative electrode lug 132 through the limiting part 1113, not only enhances the strength of the entire cover 111, but also facilitates the subsequent accurate welding of the negative electrode lug 132 and the welding part 1111 to avoid the negative electrode lug during the welding process. The force deflection of 132 causes it to be close to the inner wall of the casing 12 , thereby causing poor welding and poor performance of the battery core 13 . In addition, since the limiting portion 1113 can surround the negative electrode tab 132, damage to the negative electrode tab 132 when assembling the battery core 13 can be avoided.

For example, the surface of the limiting portion 1113 that is in contact with the negative electrode tab 132 is inclined to improve the restraint ability of the negative electrode tab 132 and avoid the negative electrode tab 132 from being offset as much as possible.

Considering that after the battery core 13 is put into the case 12 through the opening at the bottom end of the case 12, it needs to be covered and fixed at the opening by the cover plate 111, that is, the outer peripheral edge of the cover plate 111 and the outer edge of the case 12 are soldered. The bottom ends are welded together, so that the solder portion 14 is formed at the connection between the housing 12 and the cover 111 , thereby achieving a stable connection between the cover 111 and the housing 12 .

Of course, as shown in FIGS. 10 to 12 , in other embodiments, a first chamfer can also be provided on the housing 12 along the edge of the opening, and a corresponding second chamfer can be provided on the cover 111 . When the cover plate 111 and the casing 12 are welded, the welding bead 15 can be formed at the connection between the casing 12 and the cover 111, which not only facilitates welding and reduces stress concentration, but also improves the connection between the cover 111 and the casing 12. of stability.

In the description of this specification, reference to the description of the terms "some embodiments," "other embodiments," etc. means that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present application. or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Illustratively, the cover plate 111 in the embodiment of the present application is nickel-plated low carbon steel (nickel plating layer thickness 0.5 μm-3 μm), stainless steel, or nickel-plated copper.

For example, the material of the housing 12 in the embodiment of the present application is nickel-plated low carbon steel or stainless steel.

For example, the material of the negative electrode tab 132 in the embodiment of the present application is nickel-plated copper or copper.

The nickel plating layer on the cover 111 and the nickel plating layer on the nickel-plated shell are made of the same material to facilitate welding and can also reduce the internal resistance of the material. The low carbon steel base material has a high resistivity. By plating a layer of nickel on both the front and back surfaces of the low carbon steel base material, it is easy to weld with the (nickel-plated) shell and the resistance can be reduced at the same time. The resistivity of stainless steel will be high, but after welding with the (nickel-plated) shell, it can effectively prevent the (nickel-plated) shell from rusting. The copper base material has a low resistivity. By plating a layer of nickel on both the front and back surfaces of the copper base material, it is easy to weld with the (nickel-plated) shell.

The cover plate 111 is welded to the negative electrode tab 132. The negative electrode tab 132 is made of copper. In order to facilitate welding, the surface of the negative electrode tab 132 is also plated with nickel, and the surface of the cover plate 111 is also plated with a layer of nickel. At the same time, nickel also helps the solder joints resist corrosion.

Claims (14)

1. A cap assembly for a battery. The battery includes an electric core (13) and a housing (12) for accommodating the electric core (13). The cap assembly includes:

   The busbar (112) is arranged in the housing (12), and the busbar (112) is attached to the top of the battery core (13) to connect with the battery core. (13)Connection;

   Plastic pad (1142), the plastic pad (1142) is located between the housing (12) and the manifold plate (112), and the surface of the plastic pad (1142) is concave and convex.
2. The cap assembly according to claim 1, wherein a plurality of first annular grooves (11421) are provided on the top surface of the plastic pad (1142), and the plurality of first annular grooves (11421) are arranged along the The plastic pads (1142) are equidistantly distributed in the radial direction.
3. The cap assembly according to claim 2, wherein a plurality of second annular grooves (11422) are provided on the bottom surface of the plastic pad (1142), and the plurality of second annular grooves (11422) are formed along the Radially equidistant distribution of plastic pads (1142).
4. The cap assembly of claim 3, wherein the first annular grooves (11421) and the second annular grooves (11422) are staggered.
5. The cap assembly according to any one of claims 1 to 4, further comprising:

   Terminal (113), the terminal (113) is installed at the top of the housing (12) and is electrically connected to the bus plate (112);

   Sealing ring (1141), the sealing ring (1141) is located between the housing (12) and the terminal (113), and the sealing ring (1141) penetrates the plastic gasket (1142).
6. The cap assembly according to any one of claims 1 to 4, further comprising a cover plate (111), which is disposed at the bottom end of the housing (12) and connected with the battery core (13). )connect.
7. The cap assembly according to claim 6, wherein the material of the cover plate (111) is nickel-plated low carbon steel, stainless steel or nickel-plated copper.
8. The cap assembly according to claim 7, wherein the nickel plating layer thickness of the nickel-plated low carbon steel is 0.5 μm-3 μm.
9. The cap assembly according to claim 1, wherein the housing (12) is made of nickel-plated low carbon steel or stainless steel.
10. The cap assembly according to claim 6, wherein the cover plate (111) is connected to the negative electrode tab of the battery core (13), and the material of the negative electrode tab (132) is nickel-plated copper or copper.
11. A battery, a battery core (13), a casing (12) and a cap assembly according to any one of claims 1 to 10, the casing (12) is used to accommodate the battery core (13), so The cap assembly is connected to the battery core (13) and the housing (12) respectively.
12. A battery module includes a plurality of batteries according to claim 11, the plurality of batteries being arranged in multiple rows and columns.
13. A battery pack includes a box body and a battery module as claimed in claim 12, wherein the battery module is arranged in the box body.
14. A vehicle includes a vehicle body and a battery pack according to claim 13, wherein the battery pack is disposed in the vehicle body.

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