Pack structure of low-voltage lithium battery

Abstract

The utility model discloses a low-voltage lithium battery pack structure which comprises a shell and a battery module, and an accommodating cavity is formed in the shell; the battery module is arranged in the accommodating cavity, the battery module comprises a battery cell main body and a BMS (Battery Management System) device, the battery cell main body is square, the BMS device is arranged on any one of four side surfaces of the square, and the BMS device is connected with a positive electrode and a negative electrode of the battery cell main body through a connecting bar. According to the utility model, the BMS device is assembled on the end plate or the side plate of the battery module, so that the height of the module is reduced, and the technical problems that the size of the battery module assembled into a Pack structure is relatively large and the size boundary requirement of a low-voltage lithium battery is not met are solved.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage lithium battery technology, and in particular to a low-voltage lithium battery pack structure. Background Technology

[0002] Lithium-ion battery-powered parking air conditioning starters are widely used in commercial vehicles. With technological advancements and simplified processes, higher demands are being placed on the size limits and multi-scenario applicability of low-voltage lithium-ion batteries. However, the existing BMS (Battery Management System) for low-voltage lithium-ion batteries is typically designed at the top of the battery module, resulting in a relatively high module height and consequently a large battery pack structure that occupies significant space, failing to meet the size requirements of low-voltage lithium-ion batteries. Furthermore, patent literature on pack structures in this field does not address this issue. For example, the Chinese utility model patent "Lithium-ion Battery Pack Structure" (CN215119096U) addresses the problem of reduced wiring and improved wiring redundancy in existing pack structures. Therefore, the problem of the large size of low-voltage lithium-ion battery pack structures remains unresolved. Utility Model Content

[0003] In view of this, the present invention proposes a low-voltage lithium battery pack structure in which the BMS device is assembled on the end plate or side plate of the battery module, thereby reducing the module height and solving the technical problem that the battery module is too large after being assembled into a pack structure, which does not meet the size boundary requirements of low-voltage lithium batteries.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A low-voltage lithium battery pack structure, comprising:

[0006] The outer casing has an internal cavity;

[0007] A battery module is disposed in the receiving cavity. The battery module includes a cell body and a BMS device. The cell body is square, and the BMS device is disposed on any one of the four sides of the square. The BMS device is connected to the positive and negative terminals of the cell body through a connector.

[0008] In some embodiments, the BMS device includes a BMS and a mounting bracket, the mounting bracket being disposed on any side of the battery cell body, and the BMS being mounted on the mounting bracket.

[0009] In some embodiments, the battery cell body includes a battery cell, an end plate, and a side plate. Multiple battery cells are arranged in a group. Two end plates are respectively disposed on the outer sides of the two outermost battery cells. Two side plates are respectively disposed on the other two sides of the multiple battery cells. The end plates and side plates are fixed by riveting. The BMS is mounted on the end plate or on the side plate by the mounting bracket.

[0010] In some embodiments, the cell body further includes a buffer pad, and a plurality of the buffer pads are disposed between every two adjacent cells.

[0011] In some embodiments, the battery module further includes a CCS device disposed on top of the cell body.

[0012] In some embodiments, the housing includes a lower housing and a upper cover, the lower housing having the receiving cavity formed inside, and the upper cover being disposed on top of the receiving cavity to seal the receiving cavity.

[0013] In some embodiments, rivet nuts are provided at the four corners of the bottom surface of the lower housing, and the battery module is fixed in the lower housing by long bolts and the four rivet nuts.

[0014] In some embodiments, the distance between the four sides of the battery module and the four inner walls of the lower housing is 3mm to 5mm.

[0015] In some embodiments, an adhesive groove is formed on the inner edge of the upper cover, and the adhesive groove is filled with adhesive to bond it to the lower housing.

[0016] In some embodiments, the top cover is an integrally molded injection-molded structure containing inserts.

[0017] Compared with the prior art, the beneficial effects of this utility model mainly include:

[0018] This invention provides a low-voltage lithium battery pack structure. By assembling the BMS device on any side of the cell body, the side of the cell body in both length and width directions can be fully utilized, thereby greatly reducing the height of the battery module. The height of the battery module after being placed into the housing cavity and assembled into a pack structure is also greatly reduced, thus reducing the space required for the battery pack and meeting the size requirements of low-voltage lithium batteries. Furthermore, the arrangement of this invention can shorten the length of the connecting bar, thereby reducing the component cost of the battery pack and making it easier to achieve automated and large-scale production. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the low-voltage lithium battery pack described in this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of the battery module described in this utility model.

[0021] The annotations in the attached figures are explained as follows:

[0022] 100. Outer shell; 110. Lower housing; 120. Top cover;

[0023] 200. Battery module; 210. Battery cell body; 211. Battery cell; 212. End plate; 213. Side plate; 214. Buffer pad; 220. BMS device; 230. CCS device. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0025] To address the issue that existing low-voltage lithium batteries have BMS devices mounted on top of the battery, resulting in a high pack structure that does not meet the size constraints of low-voltage lithium batteries, this invention proposes a low-voltage lithium battery pack structure. The improved solution is to place the BMS devices on the side, thereby reducing the height.

[0026] like Figure 1 As shown, the low-voltage lithium battery pack structure provided by this utility model includes a housing 100 and a battery module 200. The housing 100 has a receiving cavity, and the battery module 200 is disposed in the receiving cavity. The battery module 200 includes a cell body 210 and a BMS device 220. The cell body 210 is square, and the BMS device 220 is disposed on any one of the four sides of the square. The BMS device 220 is connected to the positive and negative terminals of the cell body 210 through a connecting bar.

[0027] Unlike existing technologies, this invention assembles the BMS device 220 on any side of the cell body 210 instead of the top surface. This fully utilizes the sides of the cell body 210 in both length and width directions, thereby significantly reducing the height of the battery module 200. Consequently, the height of the battery module 200 after being assembled into a pack structure within the housing 100 is also greatly reduced, thus minimizing the space required for the battery pack and meeting the dimensional requirements of low-voltage lithium batteries. Furthermore, this design shortens the length of the connecting strip, thereby reducing the component costs of the battery pack and facilitating automated and mass production.

[0028] In one embodiment, the BMS device 220 includes a BMS and a mounting bracket, the mounting bracket being disposed on any side of the cell body 210, and the BMS being mounted on the mounting bracket.

[0029] In this embodiment, the BMS device 220 is preferably mounted on the side plate 213 of the cell body 210.

[0030] In one embodiment, the battery cell body 210 includes a battery cell 211, two end plates 212, and two side plates 213. Multiple battery cells 211 are arranged in a group according to a certain pattern. The two end plates 212 are respectively disposed on the outer sides of the two outermost battery cells 211, and the two side plates 213 are respectively disposed on the other two sides of the multiple battery cells 211. The end plates 212 and the side plates 213 are respectively provided with fixing holes and riveting holes for fixing and connecting with each other and with other components. This part is a common technology in the art and will not be described in detail here.

[0031] In one embodiment, the battery cell 211 is a square aluminum shell battery cell, the end plate 212 is a sheet metal end plate with a certain degree of elasticity to accommodate multiple battery cells 211; the side plate 213 is an aluminum alloy side plate, and the side plate 213 and the end plate 212 are fixed by riveting and then bound with steel straps. The BMS is installed on the side plate 213 by a mounting bracket and is connected to the positive and negative output terminals of the battery cell 211 by connecting the connection array.

[0032] In one embodiment, the cell body 210 further includes a buffer pad 214, and a plurality of the buffer pads 214 are disposed between every two adjacent cells 211 for protecting the cells 211.

[0033] In one embodiment, the battery module 200 further includes a CCS device 230, which is disposed on top of the cell body 210.

[0034] CCS stands for Cells Contact System integrated busbar.

[0035] In one embodiment, the CCS device 230 integrates components such as an aluminum bar, temperature acquisition, and voltage acquisition. The CCS device 230 is connected to the electrode post of the battery cell 211 by laser welding through the aluminum bar. In this embodiment, the CCS device 230, the connecting bar, the side plate 213 and the insulating sheet, the BMS and the mounting bracket, etc. can all be inherited before the material arrives, reducing the battery packaging and assembly process and improving the production cycle.

[0036] In one embodiment, the housing 100 includes a lower housing 110 and an upper cover 120, wherein the lower housing 110 has the receiving cavity formed inside, and the upper cover 120 is disposed on top of the receiving cavity to seal the receiving cavity.

[0037] In one embodiment, the lower housing 110 is made of Q235 sheet metal, which has the advantages of simple structure, low cost and high strength; rivet nuts are provided at the four corners of the inner bottom surface of the lower housing 110, and the battery module 200 is fixed in the lower housing 110 by four long bolts and four rivet nuts.

[0038] In one embodiment, the distance between the four sides of the battery module 200 and the four inner walls of the lower housing 110 is 3mm to 5mm.

[0039] In one embodiment, the upper cover 120 is an injection-molded structure containing inserts. The inner edge of the upper cover 120 has a glue groove, which is filled with glue to seal and bond with the lower housing 110, thus meeting the IP67 dustproof and waterproof rating.

[0040] In one embodiment, the battery module 200 is designed with battery pack polarity conversion in mind. Plastic brackets are designed on the positive and negative output terminals of the cell body 210, which can complete the positive and negative polarity conversion of the battery pack with minimal design changes.

[0041] In summary, the low-voltage lithium battery pack structure provided by this utility model involves stacking multiple battery cells 211, clamping and pressing both ends with a clamping fixture, then assembling end plates 212 and side plates 213 on both sides and fixing them with rivets. After fixing, the fixture can be released. Next, the CCS device 230 is installed on the top of the battery cell body 210, the aluminum bar is laser welded to the battery cell terminal, the BMS is assembled on the side plate 213 through the mounting bracket, tightened with nuts, and the connecting strip is installed to complete the fabrication of the battery module 200. After the battery module 200 is assembled, it is lifted into the lower housing 110 using a hook, and four M6 long bolts are used to fix the battery module 200 to the lower housing 110, so that the battery module 200 and the lower housing 110 are firmly connected as one unit. Finally, the upper cover 120 is sealed.

[0042] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A low-voltage lithium battery pack structure, characterized in that, include: The outer casing has an internal cavity; A battery module is disposed in the receiving cavity. The battery module includes a cell body and a BMS device. The cell body is square, and the BMS device is disposed on any one of the four sides of the square. The BMS device is connected to the positive and negative terminals of the cell body through a connector.

2. The low-voltage lithium battery pack structure according to claim 1, characterized in that, The BMS device includes a BMS and a mounting bracket. The mounting bracket is disposed on any side of the battery cell body, and the BMS is mounted on the mounting bracket.

3. The low-voltage lithium battery pack structure according to claim 2, characterized in that, The battery cell body includes a battery cell, an end plate, and a side plate. Multiple battery cells are arranged in a group. Two end plates are respectively disposed on the outer sides of the two outermost battery cells. Two side plates are respectively disposed on the other two sides of the multiple battery cells. The end plates and side plates are fixed by riveting. The BMS is mounted on the end plate or on the side plate by the mounting bracket.

4. The low-voltage lithium battery pack structure according to claim 3, characterized in that, The cell body also includes a buffer pad, and a plurality of the buffer pads are disposed between every two adjacent cells.

5. The low-voltage lithium battery pack structure according to claim 1, characterized in that, The battery module also includes a CCS device, which is disposed on the top of the cell body.

6. The low-voltage lithium battery pack structure according to claim 1, characterized in that, The outer casing includes a lower housing and an upper cover. The lower housing has the receiving cavity inside, and the upper cover is disposed on top of the receiving cavity to seal the receiving cavity.

7. The low-voltage lithium battery pack structure according to claim 6, characterized in that, The lower housing has rivet nuts at each of the four corners of its bottom surface, and the battery module is fixed in the lower housing by long bolts and the four rivet nuts.

8. The low-voltage lithium battery pack structure according to claim 7, characterized in that, The distance between the four sides of the battery module and the four inner walls of the lower housing is 3mm to 5mm.

9. The low-voltage lithium battery pack structure according to claim 6, characterized in that, The inner edge of the upper cover has a glue groove, which is filled with glue to bond it to the lower box.

10. The low-voltage lithium battery pack structure according to claim 9, characterized in that, The top cover is an integral injection-molded structure containing inserts.

Images