Battery pack

Abstract

The utility model discloses a battery pack, which comprises: a battery cell assembly, the battery cell assembly comprises a circuit board and a battery cell, and the circuit board is fixedly connected to the side part of the battery cell; the steel sheet rubber frame shell is internally provided with a containing space, the circumferential size of the containing space is matched with the circumferential size of the battery core assembly, and the battery core assembly is arranged in the containing space; the expansion absorption layers are arranged on the two opposite surfaces of the battery cell and abut against the inner wall of the steel sheet rubber frame shell, and each expansion absorption layer is of a structure shaped like a Chinese character'hui 'and located on the edge of the surface of the battery cell. According to the battery pack, the circumferential size of the accommodating space is set to be adaptive to the circumferential size of the battery cell assembly, so that the battery cell and the circuit board can be fixedly mounted without low-pressure injection molding, the packaging procedure of the battery pack is simplified, and the packaging cost of the battery pack is greatly reduced. Meanwhile, thermal expansion of the battery cells can be absorbed in the battery pack through the arrangement of the expansion absorption layer, potential safety hazards such as blasting and thermal runaway caused by deformation of the battery pack are avoided, and the safety of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the field of battery packaging technology, and in particular to a battery pack. Background Art

[0002] Lithium-ion batteries are widely used in electronic devices, energy storage devices, and new energy vehicles due to their advantages such as large capacity and long discharge time. Lithium-ion battery cells, especially polymer lithium-ion battery cells, are generally packaged in soft packaging, so the overall structure of lithium-ion batteries needs to provide adequate protection for the cells. The traditional battery packaging structure is to cover the battery cell with a plastic shell. The plastic shell can be formed into an upper shell and a lower shell separately and then closed to cover the battery cell, or it can be formed by directly injecting plastic material onto the battery cell. However, due to the limitations of the plastic molding process, it is difficult to make the plastic shell very thin, resulting in the overall thickness of the battery being too thick. If the plastic shell is forced to be thin, problems such as glue overflow or bulging may occur.

[0003] To this end, the prior art discloses a battery with a steel sheet rubber frame. During assembly, the fixed connection structure of the battery cell and circuit board is simply installed into the steel sheet rubber frame. Low-pressure injection molding is then performed to fill the gaps between the steel sheet rubber frame, the battery cell, and the circuit board with hot melt adhesive to form a rubber compound. The label is then tightly wrapped around the steel sheet rubber frame, battery cell, and rubber compound to complete the package. In this way, the thinner steel sheet can reduce the thickness of the battery. Moreover, the hardness of the steel sheet is much greater than that of plastic, which can better protect the battery cell and prevent glue overflow or bulging.

[0004] However, low-pressure injection molding is not only cumbersome and costly, but the thermal expansion of the battery cells will cause the entire battery to expand, resulting in severe deformation of the battery and posing safety risks of explosion and thermal runaway. Utility Model Content

[0005] In order to solve the above-mentioned defects in the prior art, the purpose of this application is to provide a battery pack that can achieve fixed installation of battery cells and circuit boards without low-pressure injection molding, which not only simplifies the process and reduces costs, but also can absorb the thermal expansion of the battery cells in the battery pack, avoiding safety hazards such as explosion and thermal runaway caused by deformation of the battery pack, thereby improving the safety of the battery pack.

[0006] The technical solutions provided according to the purpose of this application are as follows:

[0007] A battery pack, comprising:

[0008] The battery cell assembly includes a circuit board and a battery cell, and the circuit board is fixedly connected to the side of the battery cell;

[0009] A steel sheet rubber frame housing is provided with a receiving space in the steel sheet rubber frame housing, the circumferential dimension of the receiving space is adapted to the circumferential dimension of the battery cell assembly, and the battery cell assembly is arranged in the receiving space;

[0010] The expansion absorbing layer is arranged on two opposite surfaces of the battery core and abuts against the inner wall of the steel sheet rubber frame shell. The expansion absorbing layer has a "U"-shaped structure and is located at the surface edge of the battery core.

[0011] Furthermore, the thickness of the expansion absorbing layer is equal to the thickness increased by the battery cell due to thermal expansion.

[0012] Furthermore, the steel sheet rubber frame housing includes a steel sheet rubber frame and a steel sheet cover plate, the steel sheet cover plate is arranged on the steel sheet rubber frame to form an accommodating space therebetween, and the steel sheet cover plate and the steel sheet rubber frame are detachably connected via a snap-fit ​​structure.

[0013] Furthermore, the steel sheet plastic frame includes a first steel sheet and a plastic frame, wherein the plastic frame is provided at a circumferential edge of the first steel sheet and protrudes relative to a surface of the first steel sheet to enclose an accommodation space;

[0014] The accommodating space is divided into a first space and a second space by a partition plate. The circumferential size of the first space is adapted to the circumferential size of the battery cell to accommodate and fix the battery cell. The circuit board is arranged in the second space and abuts the plastic frame.

[0015] Furthermore, the steel sheet cover includes a fixedly connected second steel sheet and a bracket, the second steel sheet is arranged corresponding to the first space, and the bracket is arranged corresponding to the second space and extends into the second space to abut against a side of the circuit board away from the plastic frame.

[0016] Furthermore, the bracket extends toward the second space to form an elastic arm, and a receiving groove adapted for the elastic arm is provided in the second space. The elastic arm is provided in the receiving groove and abuts against a side of the circuit board away from the plastic frame.

[0017] Furthermore, the elastic arm and the circuit board are interference-fitted, and the interference between the elastic arm and the circuit board is 0.15-0.3 mm.

[0018] Furthermore, the elastic arm is a vertically arranged bridge-shaped structure, and the arch portion of the elastic arm abuts against the circuit board, and the end of the bottom of the elastic arm away from the circuit board is arranged to tilt up and down toward the circuit board.

[0019] Furthermore, the tabs of the battery cell extend out and are fixedly connected to the circuit board, and the bracket is provided with avoidance holes corresponding to the tabs.

[0020] Furthermore, the first steel sheet and the plastic frame are inlaid and injection-molded into a steel sheet plastic frame of an integrated structure, and a first through hole is opened in the embedded portion of the first steel sheet;

[0021] The second steel sheet and the bracket are inlaid and injection-molded to form a steel sheet cover with an integrated structure, and a second through hole is opened in the embedded part of the second steel sheet.

[0022] The battery pack provided by this application has the following technical effects:

[0023] By adapting the circumferential dimensions of the housing to those of the cell assembly, the cells and circuit board can be securely mounted without low-pressure injection molding, simplifying the battery pack packaging process and significantly reducing packaging costs. Furthermore, the expansion-absorbing layer absorbs the thermal expansion of the cells within the battery pack, preventing potential safety hazards such as explosion and thermal runaway caused by deformation, thereby improving the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of the battery pack of this application;

[0025] Figure 2 An exploded view of the battery pack for this application;

[0026] Figure 3 A cross-sectional view of the battery pack of this application;

[0027] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0028] Figure 5 This is an exploded view of the steel sheet cover for this application;

[0029] Figure 6 This is an exploded view of the steel sheet rubber frame of this application;

[0030] Figure 7 This is a schematic diagram of the structure of the battery cell assembly of this application.

[0031] Reference numerals:

[0032] 1. Battery cell assembly; 11. Circuit board; 12. Battery cell; 121. Tab; 2. Steel sheet rubber frame shell; 21. Accommodation space; 211. First space; 212. Second space; 213. Accommodation groove; 22. Steel sheet rubber frame; 221. First steel sheet; 2211. First through hole; 2212. Boss; 222. Rubber frame; 223. Partition plate; 224. Slot; 23. Steel sheet cover; 231. Second steel sheet; 2311. Second through hole; 232. Bracket; 2321. Avoidance hole; 233. Elastic arm; 234. Hook; 3. Expansion absorption layer; 4. Label. DETAILED DESCRIPTION

[0033] For better understanding and implementation, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0034] In the description of this application, it should be noted that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0036] See Figure 2 The present application discloses a battery pack, comprising a battery cell assembly 1, a steel sheet rubber frame shell 2 and an expansion absorbing layer 3. The battery cell assembly comprises a circuit board 11 and a battery cell 12, and the circuit board 11 is fixedly connected to the side of the battery cell 12. An accommodating space 21 is provided in the steel sheet rubber frame shell 2, and the circumferential dimension of the accommodating space is adapted to the circumferential dimension of the battery cell assembly 1, and the battery cell assembly 1 is arranged in the accommodating space 21. The expansion absorbing layer 3 is provided on the two opposite surfaces of the battery cell 12 and abuts against the inner wall of the steel sheet rubber frame shell 2. The expansion absorbing layer 3 is a "U"-shaped structure and is located at the surface edge of the battery cell 12.

[0037] Taking the rectangular structure of the battery cell 12 and the circuit board 11 as an example, only one battery cell 12 can be provided, or Figure 7 Two or more cells are stacked as shown. A circuit board 11 is positioned to the side of a cell 12, with one surface of the circuit board 11 facing a side of the cell 12. The circuit board 11 is spaced apart from the cell 12. A tab 121 of the cell 12 extends outward and is fixedly connected to the circuit board 11. The tab 121 is located on one side of the cell 12 and extends outward to be spot-welded to the circuit board 11, thereby achieving electrical connection between the cell 12 and the circuit board 11.

[0038] The side of the steel sheet rubber frame shell 2 is a rubber frame structure, and the bottom is a steel sheet structure. The side circumferential dimension of the accommodating space 21 of the steel sheet rubber frame shell 2 is adapted to the side axial dimension of the battery cell assembly 1, so that when the battery cell assembly 1 is assembled in the accommodating space 21, the side wall of the battery cell assembly 1 abuts against the inner wall of the steel sheet rubber frame shell 2 to ensure the stable installation of the battery cell assembly 1.

[0039] The two opposing surfaces of the battery cell assembly 1 are spaced apart from the inner walls of the corresponding steel sheet rubber frame housing 2, thereby providing an expansion absorbing layer 3 between the battery cell assembly 1 and the steel sheet rubber frame housing 2. The expansion absorbing layer 3 thereby separates the battery cell 12 from the steel sheet structure. Furthermore, since thermal expansion of the battery cell 12 generally occurs in the central region of the battery cell 12, the "U"-shaped expansion absorbing layer 3 can utilize the central region to absorb the thermal expansion of the battery cell 12, thereby absorbing the thermal expansion of the battery cell 12 within the battery pack, thereby preventing safety hazards such as explosion and thermal runaway caused by battery pack deformation.

[0040] Thus, by adapting the circumferential dimensions of the accommodation space 21 to the circumferential dimensions of the battery cell assembly 1, the present application enables the fixed installation of the battery cell 12 and the circuit board 11 without the need for low-pressure injection molding, thereby simplifying the battery pack packaging process and significantly reducing the packaging cost of the battery pack. Furthermore, the provision of the expansion-absorbing layer 3 can absorb the thermal expansion of the battery cell 12 within the battery pack, preventing safety hazards such as explosion and thermal runaway caused by battery pack deformation, thereby improving the safety of the battery pack.

[0041] The expansion-absorbing layer 3 is an elastic structure, such as foam, and is bonded to the battery cell 12 with a heat-resistant adhesive. The thickness of the expansion-absorbing layer 3 is equal to the thickness of the battery cell 12 due to thermal expansion. That is, regardless of whether there is a single battery cell 12 or two or more, the thickness of the expansion-absorbing layer 3 on one side is equal to the thickness of the battery cell 12 due to expansion toward that side. This allows the thermal expansion of the battery cell 12 to be absorbed within the battery pack, ensuring safety and facilitating assembly.

[0042] See Figure 2 、 Figure 5 and Figure 6 The steel-frame housing 2 includes a steel frame 22 and a steel cover 23. The steel cover 23 is mounted on the steel frame 22 to form a receiving space 21 therebetween. The steel cover 23 and the steel frame 22 are detachably connected by a snap-fit ​​structure. This detachable connection between the steel frame 22 and the steel cover 23 facilitates assembly of the battery cell assembly 1.

[0043] A plurality of hooks 234 are spaced apart along the circumferential edge of the steel cover plate 23, and a plurality of slots 224 are provided along the circumference of the steel rubber frame 22. The hooks 234 are equal in number to the slots 224 and are positioned in a one-to-one correspondence, with the hooks 234 fitting snugly into the corresponding slots 224. When the steel cover plate 23 is attached to the steel rubber frame 22, the hooks 234 engage in the corresponding slots 224, achieving a removable connection between the steel cover plate 23 and the steel rubber frame 22.

[0044] Specifically, the steel sheet plastic frame 22 includes a first steel sheet 221 and a plastic frame 222. The plastic frame 222 is provided at the circumferential edge of the first steel sheet 221 and protrudes from one surface of the first steel sheet 221 to enclose the accommodating space 21. The steel sheet cover 23 includes a fixedly connected second steel sheet 231 and a bracket 232. The steel sheet cover 23 covers the opening of the plastic frame 222 to enclose the accommodating space 21. The plastic frame 222 serves to enclose the battery cell assembly 1. The first steel sheet 221 and the second steel sheet 231 are relatively thin, which greatly reduces the thickness of the battery pack and helps to improve the strength of the battery pack.

[0045] The first steel sheet 221 and the plastic frame 222 are inlaid and injection-molded to form an integral steel sheet plastic frame 22, and the second steel sheet 231 and the bracket 232 are inlaid and injection-molded to form an integral steel sheet cover 23. This simplifies the manufacturing process and avoids problems such as deformation and surface unevenness when the first steel sheet 221 and the second steel sheet 231 are installed separately.

[0046] To enhance the structural stability of the steel sheet rubber frame 22 and the steel sheet cover plate 23, a first through-hole 2211 is defined in the embedded portion of the first steel sheet 221, and a second through-hole 2311 is defined in the embedded portion of the second steel sheet 231. At least one second through-hole 2311 is defined at one end of the second steel sheet 231 along its length. During mold opening and injection molding, the bracket 232 not only covers the end surface of the second steel sheet 231 but also embeds within the second through-hole 2311, enhancing the tightness of the connection between the bracket 232 and the second steel sheet 231. At least one first through hole 2211 is formed at one end of the first steel sheet 221 in the longitudinal direction, and the circumferential edge of the first steel sheet 221 protrudes toward a surface to form a plurality of latching protrusions 2212 arranged at intervals. After mold opening and injection molding, the plastic frame 222 is not only provided at the circumferential edge of the first steel sheet 221, but also embedded in the first through hole 2211, and the latching protrusions 2212 are embedded in the plastic frame 222, thereby improving the tightness of the connection between the plastic frame 222 and the first steel sheet 221.

[0047] On this basis, the accommodating space 21 is divided into a first space 211 and a second space 212 by a partition plate 223. The circumferential dimensions of the first space 211 are adapted to the circumferential dimensions of the battery cell 12 to accommodate and secure the battery cell 12. The circuit board 11 is disposed in the second space 212 and abuts the plastic frame 222. The first space 211 and the second space 212 are distributed along the length of the accommodating space 21. Because the tabs 121 of the battery cell 12 are spot-welded to the circuit board 11, the partition plate 223 is disposed discontinuously to facilitate the extension of the tabs 121 to connect to the circuit board 11. Furthermore, the partition plate 223 cooperates with the plastic frame 222 to secure the battery cell 12 within the first space 211, eliminating the need for low-pressure injection molding to secure the battery cell 12 within the battery pack.

[0048] Due to the distribution structure of the accommodating spaces 21, the second steel sheet 231 is positioned corresponding to the first space 211, and the bracket 232 is positioned corresponding to the second space 212 and extends into the second space 212 to abut the side of the circuit board 11 away from the plastic frame 222. The abutment of the bracket 232 against the circuit board 11 ensures a seamless connection between the circuit board 11 and the plastic frame 222, thereby ensuring a stable electrical connection between the battery pack and the external circuit.

[0049] The bracket 232 is provided with an escape hole 2321 corresponding to the tab 121. The tab 121 passes through the escape hole 2321 and is spot-welded to the circuit board 11.

[0050] Further, see Figure 3 、 Figure 4 and Figure 5 The bracket 232 extends toward the second space 212 to form an elastic arm 233. A receiving slot 213 adapted for the elastic arm 233 is provided within the second space 212. The elastic arm 233 is positioned within the receiving slot 213 and abuts the side of the circuit board 11 away from the plastic frame 222. The provision of the elastic arm 233 further enhances the securing of the circuit board 11, preventing a gap between the circuit board 11 and the plastic frame 222. The receiving slot 213 can be formed by cutting a groove within the second space 212, or by providing side panels within the second space 212 to enclose the receiving slot 213. Regardless of the structure, the elastic arm 233 is required to be elastically secured within the receiving slot 213.

[0051] The spring arm 233 has an interference fit with the circuit board 11, with an interference margin of 0.15-0.3 mm. Within this interference margin, the spring arm 233 can provide thrust to the circuit board 11 to prevent a gap from forming between the circuit board 11 and the plastic frame 222, while also preventing damage to the circuit board 11 from excessive compression.

[0052] The elastic arm 233 is a vertically arranged bridge-shaped structure, with the arch portion of the elastic arm 233 abutting the circuit board 11. The bottom end of the elastic arm 233, facing away from the circuit board 11, is tilted upward and downward toward the circuit board 11. The middle region of the elastic arm 233 forms a bridge arch portion that abuts the circuit board 11. The two ends of the bridge arch portion are vertical sections that connect the bracket 232 and the receiving slot 213. The connection between the elastic arm 233 and the receiving slot 213 is an angled structure. When the circuit board 11 applies a reverse force to the elastic arm 233, the angled structure can be firmly inserted into the receiving slot 213, ensuring that the elastic arm 233 is stably stressed and preventing the elastic arm 233 from ejecting from the receiving slot 213, thereby ensuring the stable installation of the circuit board 11.

[0053] In addition, see Figure 1 and Figure 2The battery pack of the present application also includes a label 4, which is tightly wrapped around the outer surface of the steel sheet rubber frame shell 2 and exposes the side wall of the rubber frame 222 corresponding to the circuit board 11 and the side wall opposite to the side wall.

[0054] The above is the specific structure of the battery pack of the present application. During the packaging operation, the first steel sheet 221 and the rubber frame 222 are first inlaid and injection molded into a steel sheet rubber frame 22, and the second steel sheet 231 and the bracket 232 are inlaid and injection molded into a steel sheet cover 23, and the circuit board 11 is fixedly connected to the battery cell 12. Then, the expansion absorption layer 3 is attached to the two opposite surfaces of the battery cell 12, and then the battery cell assembly 1 with the expansion absorption layer 3 is placed in the accommodating space 21 of the steel sheet rubber frame 22, so that the battery cell 12 is fixed in the first space 211 and the circuit board 11 is fixed in the second space 212. Then, the steel sheet cover 23 is covered on the steel sheet rubber frame 22 to seal the accommodating space 21, and the elastic arm 233 is fixed in the accommodating groove 213 and abuts the circuit board 11. Finally, the label 4 is covered on the outer surface of the steel sheet rubber frame shell 2 to complete the packaging of the battery pack.

[0055] The technical means disclosed in the present application are not limited to those disclosed in the above-mentioned embodiments, but also include technical solutions composed of any combination of the above-mentioned technical features. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of the present application, and such improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A battery pack, characterized in that: include: A battery cell assembly (1), comprising a circuit board (11) and a battery cell (12), wherein the circuit board (11) is fixedly connected to a side of the battery cell (12); A steel sheet rubber frame housing (2), wherein a receiving space (21) is provided in the steel sheet rubber frame housing (2), the circumferential dimension of the receiving space being adapted to the circumferential dimension of the battery core assembly (1), and the battery core assembly (1) being arranged in the receiving space (21); An expansion absorbing layer (3) is provided on two opposite surfaces of the battery core (12) and abuts against the inner wall of the steel sheet rubber frame shell (2); the expansion absorbing layer (3) is a "U"-shaped structure and is located at the surface edge of the battery core (12).

2. The battery pack according to claim 1, wherein: The thickness of the expansion absorbing layer (3) is equal to the thickness increased by the battery core (12) after thermal expansion.

3. The battery pack according to claim 1 or 2, characterized in that: The steel sheet rubber frame housing (2) comprises a steel sheet rubber frame (22) and a steel sheet cover plate (23), wherein the steel sheet cover plate (23) is covered on the steel sheet rubber frame (22) to form the accommodation space (21) therebetween, and the steel sheet cover plate (23) and the steel sheet rubber frame (22) are detachably connected via a snap-fit ​​structure.

4. The battery pack according to claim 3, wherein: The steel sheet plastic frame (22) comprises a first steel sheet (221) and a plastic frame (222), wherein the plastic frame (222) is arranged on the circumferential edge of the first steel sheet (221) and protrudes relative to a surface of the first steel sheet (221) to enclose the accommodating space (21); The accommodating space (21) is divided into a first space (211) and a second space (212) by a partition plate (223); the circumferential dimension of the first space (211) is adapted to the circumferential dimension of the battery cell (12) so as to accommodate and fix the battery cell (12); the circuit board (11) is arranged in the second space (212) and abuts against the plastic frame (222).

5. The battery pack according to claim 4, wherein: The steel sheet cover (23) comprises a second steel sheet (231) and a bracket (232) that are fixedly connected, wherein the second steel sheet (231) is arranged corresponding to the first space (211), and the bracket (232) is arranged corresponding to the second space (212) and extends into the second space (212) to abut against a side of the circuit board (11) away from the plastic frame (222).

6. The battery pack according to claim 5, wherein: The bracket (232) extends toward the second space (212) to form an elastic arm (233), and a receiving groove (213) adapted for the elastic arm (233) is provided in the second space (212). The elastic arm (233) is provided in the receiving groove (213) and abuts against a side of the circuit board (11) away from the plastic frame (222).

7. The battery pack according to claim 6, wherein: The elastic arm (233) and the circuit board (11) are interference-fitted, and the interference between the elastic arm (233) and the circuit board (11) is 0.15-0.3 mm.

8. The battery pack according to claim 6, wherein: The elastic arm (233) is a vertically arranged bridge-shaped structure, and the bridge arch portion of the elastic arm (233) abuts against the circuit board (11), and the end of the bottom of the elastic arm (233) away from the circuit board (11) is arranged to tilt upward and downward toward the circuit board (11).

9. The battery pack according to claim 5, wherein: The tab (121) of the battery cell (12) extends out and is fixedly connected to the circuit board (11), and the bracket (232) is provided with an avoidance hole (2321) corresponding to the tab (121).

10. The battery pack according to claim 5, wherein: The first steel sheet (221) and the plastic frame (222) are inlaid and injection-molded to form the steel sheet plastic frame (22) as an integral structure, and a first through hole (2211) is provided in the embedded portion of the first steel sheet (221); The second steel sheet (231) and the bracket (232) are inlaid and injection-molded to form the steel sheet cover (23) as an integral structure, and a second through hole (2311) is provided in the embedded portion of the second steel sheet (231).

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