Soft package lithium battery for light electric vehicle

Abstract

The utility model provides a soft package lithium battery for a light electric vehicle, which comprises a shell and a soft package module positioned in the shell, the shell comprises an upper shell and a lower shell which are mutually covered, the soft package module comprises a plurality of soft package battery cells which are sequentially stacked, and the adjacent soft package battery cells are bonded and connected through double-sided foam; the top surface of each soft package battery cell is provided with a battery cell tab, an epoxy plate is padded above the battery cell tab, a sampling plate is arranged above the epoxy plate, a protection plate is arranged above the sampling plate, the epoxy plate and the sampling plate are respectively provided with a mounting hole for the battery cell tab to pass through, and each soft package battery cell is welded and connected with the sampling plate through the battery cell tab. According to the PACK structure technology, a support and an inner container are omitted, the soft package module is directly arranged in the lower shell, material use and machining procedures can be reduced, the production technology is simplified, cost is reduced, and production efficiency is improved; and the size is optimized, so that the size of the battery PACK is more compact, the volume is reduced, and the energy density is improved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium battery technology, specifically relating to a soft-pack lithium battery for light electric vehicles. Background Technology

[0002] Lithium batteries are being used more and more widely in the field of light electric vehicles, mainly in electric bicycles, electric scooters and electric motorcycles.

[0003] Compared to cylindrical or prismatic cells, pouch cells for lithium-ion batteries are more fragile and flexible in structure. During the packing process, it is necessary to ensure that the cells do not deform or become damaged during packaging to maintain their structural stability.

[0004] Currently, there are many forms of pouch lithium batteries in the market, such as designing and installing brackets for pouches. For the light electric vehicle market, this will lead to excessively high material costs and a lack of market competitiveness. For example, patent application CN119812651A discloses a pouch cell bracket and its electrical connection buckle. The pouch cell bracket includes a bracket and a liquid cooling plate. The liquid cooling plate is located in the middle of the inner side of the bracket. The cell is placed between the liquid cooling plates between adjacent brackets, and the large surface of the cell contacts the liquid cooling plate for heat dissipation.

[0005] Some pouch lithium batteries are designed with epoxy boards wrapped around the pouch. This type of pack not only increases material costs but also makes production more complicated. Others use potting compound for pouch batteries, which increases material production costs, increases battery weight, makes manufacturing and maintenance inconvenient, and has no recycling value.

[0006] In summary, existing conventional soft-pack PACK solutions suffer from problems such as high material costs, cumbersome production, increased battery weight, poor heat dissipation, reduced heat dissipation efficiency, increased battery temperature, and reduced battery life. The cumbersome design may also increase potential failure points and reduce the reliability and stability of the battery PACK. Utility Model Content

[0007] To address the aforementioned technical problems in the existing technology, this utility model provides a soft-pack lithium battery for light electric vehicles.

[0008] This utility model provides a soft-pack lithium battery for light electric vehicles, including a housing and a soft-pack module located inside the housing. The housing includes an upper shell and a lower shell that overlap each other. The soft-pack module includes a plurality of soft-pack cells stacked sequentially, with adjacent soft-pack cells connected by double-sided foam bonding. The top surface of each soft-pack cell has a cell tab, an epoxy board is placed above the cell tab, a sampling plate is placed above the epoxy board, and a protective plate is placed above the sampling plate. Both the epoxy board and the sampling plate have mounting holes for the cell tabs to pass through, and each soft-pack cell is welded to the sampling plate through the cell tab.

[0009] Furthermore, foam is provided between adjacent pouch cells in the cell tab area located below the epoxy board to form safety insulation.

[0010] Furthermore, foam is placed between the bottom surface of the soft-pack module and the inner bottom surface of the lower shell to provide flexible cushioning for the soft-pack module.

[0011] Furthermore, the lower casing is filled with potting compound to fill the assembly gap between the soft-pack module and the lower casing, thus fixing the soft-pack module in place. The front and rear cells of the soft-pack module are in full contact with the inner wall of the outer casing. With the assistance of the potting compound, heat can be dissipated through the lower casing wall of the battery box, greatly improving the battery's heat dissipation capacity.

[0012] Furthermore, the upper shell and the lower shell are fixed together by screws.

[0013] Furthermore, the lower shell is provided with first reinforcing ribs around its perimeter, which provides better mechanical strength and reduces the risk of deformation and breakage of the shell.

[0014] Furthermore, the bottom surface of the lower shell has a raised center and recessed structures on both sides perpendicular to the direction of the pouch cells. This concentrates the stress on the pouch module in the middle, preventing the two bottom corners of the pouch cell package from breaking due to excessive stress.

[0015] Furthermore, the outer bottom surface of the lower shell is provided with a second reinforcing rib.

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

[0017] 1. This PACK structure technology eliminates the need for a support frame and inner liner, allowing the soft-pack mold to be directly assembled into the lower shell. This reduces material usage and processing steps, simplifies the production process, lowers costs, and improves production efficiency.

[0018] 2. Optimize the size to make the battery pack more compact, reduce volume, and increase energy density;

[0019] 3. Improved reliability, reduced connection points of internal components, and lowered the internal failure rate of the battery;

[0020] 4. The simplified design reduces potential failure points and improves the reliability and stability of the battery pack.

[0021] 5. Easy to repair: the protection board can be directly replaced after opening the top shell, and the battery cells are also easy to disassemble and have recycling value. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the soft-pack lithium battery of this utility model.

[0023] Figure 2 This is a schematic diagram of the exploded structure of the soft-pack lithium battery of this utility model.

[0024] Figure 3 This is an exploded structural diagram of the soft-pack module of this utility model.

[0025] Figure 4 This is a side view of the soft-pack lithium battery of this utility model.

[0026] Figure 5 for Figure 4 A cross-sectional view along the AA direction.

[0027] Figure 6 This is a schematic diagram of the lower shell of this utility model.

[0028] Figure 7 This is a front view structural diagram of the lower shell of this utility model.

[0029] Figure 8 for Figure 7 A sectional view along the BB direction.

[0030] Figure label:

[0031] Shell 1, upper shell 11, lower shell 12, soft-pack module 2, soft-pack battery cell 21, double-sided foam 22, battery cell tab 23, epoxy board 24, sampling board 25, protection board 26, first reinforcing rib 27, recessed structure 28, second reinforcing rib 29. Detailed Implementation

[0032] like Figures 1-8 As shown, this utility model provides a soft-pack lithium battery for light electric vehicles, including a housing 1 and a soft-pack module 2 located inside the housing 1. The housing 1 includes an upper shell 11 and a lower shell 12 that overlap each other, and the upper shell 11 and the lower shell 12 can be fixed together by screws. This fixing method is firm and reliable, with excellent waterproof performance and anti-aging properties, and is also easy to disassemble and repair without damaging the housing during the repair process.

[0033] The soft-pack module 2 includes several soft-pack battery cells 21 stacked sequentially. Adjacent soft-pack battery cells 21 are bonded together by double-sided foam 22. The top surface of the soft-pack battery cell 21 has a battery cell tab 23. An epoxy board 24 is placed above the battery cell tab 23. A sampling board 25 is placed above the epoxy board 24. A protective board 26 is placed above the sampling board 25. Both the epoxy board 24 and the sampling board 25 have mounting holes through which the battery cell tab 23 passes. Each soft-pack battery cell 21 is welded to the sampling board 25 through the battery cell tab 23.

[0034] Foam is provided between adjacent pouch cells 21 in the area of ​​cell tabs 23 located below epoxy board 24 to form safety insulation. The foam is preferably EVA.

[0035] Foam is placed between the bottom surface of the soft-pack module 2 and the inner bottom surface of the lower shell 12 to provide flexible cushioning for the soft-pack module 2. The lower shell 12 is filled with potting compound to fill the assembly gap between the soft-pack module 2 and the lower shell 12, thus securing the soft-pack module 2. After the foam and potting compound cure, they work together to provide flexible cushioning for the soft-pack module 2, allowing it to successfully pass drop and vibration tests.

[0036] The front and rear cells of the soft-pack module 2 are in full contact with the inner wall of the outer casing. With the help of potting compound, heat can be conducted through the lower shell 12 of the battery box, which greatly improves the heat dissipation capacity of the battery.

[0037] The lower casing 12 is provided with first reinforcing ribs 27 around its perimeter, providing better mechanical strength and reducing the risk of deformation and breakage of the casing. The first reinforcing ribs 27 inside the lower casing 12 can limit the bulging of the pouch cells 21, ensuring the safety and reliability of the battery pack. During drops, vibrations, compression, and collisions, the raised reinforcing ribs around the perimeter can keep the internal cells at a safe distance.

[0038] The bottom surface of the lower shell 12 has a raised center and recessed structures 28 on both sides perpendicular to the arrangement direction of the soft-pack cells 21. This concentrates the force on the soft-pack module 2 in the middle, preventing the two bottom corners of the soft-pack cell 21 from being damaged due to excessive force. To make the lower shell 12 more stable, a second reinforcing rib 29 is provided on the outer bottom surface of the lower shell 12.

Claims

1. A pouch lithium battery for a light electric vehicle, comprising a housing and a pouch module located within the housing, the housing comprising an upper shell and a lower shell that overlap each other, characterized in that, The soft-pack module includes several soft-pack battery cells stacked sequentially, with adjacent soft-pack battery cells connected by double-sided foam bonding. The top surface of the pouch cell has a cell tab, an epoxy board is placed on top of the cell tab, a sampling plate is placed on top of the epoxy board, and a protective plate is placed on top of the sampling plate. Both the epoxy board and the sampling plate have mounting holes for the cell tab to pass through. Each pouch cell is welded to the sampling plate through the cell tab.

2. The pouch lithium battery for a light electric vehicle according to claim 1, wherein Foam is provided between adjacent pouch cells, in the area of ​​the cell tabs located below the epoxy board. 3.The pouch lithium battery for a light electric vehicle according to claim 1, wherein Foam is placed between the bottom surface of the soft-pack module and the inner bottom surface of the lower shell. 4.The pouch lithium battery for a light electric vehicle according to claim 1, wherein The lower shell is filled with potting compound to fill the assembly gap between the soft-pack module and the lower shell. 5.The pouch lithium battery for a light electric vehicle according to claim 1, wherein The upper and lower shells are fixed together by screws. 6.The pouch lithium battery for a light electric vehicle according to claim 1, wherein, The lower shell is provided with a first reinforcing rib around its perimeter.

7. The soft-pack lithium battery for light electric vehicles according to claim 1, characterized in that, The bottom surface of the lower shell has a raised center and recessed structures on both sides perpendicular to the direction of the soft-pack battery cell arrangement.

8. The pouch lithium battery for light electric vehicles according to claim 7, wherein The bottom surface of the lower shell is provided with a second reinforcing rib.

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