Battery pack

Abstract

The utility model relates to a battery pack. The battery pack comprises a battery cell shell, the battery cell assembly comprises a plurality of laminated sheet-shaped battery cells, and the sheet-shaped battery cells are accommodated in the battery cell shell; the battery pack further comprises elastic supports arranged at the two longitudinal ends of the battery cell assembly. And the elastic bracket is arranged, so that the weight of the battery pack is reduced, and the battery cells are convenient to assemble.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, in particular to a lightweight and easy-to-assemble battery pack. Background Art

[0002] In the prior art, non-cylindrical battery cells are adopted in a battery pack, and a soft material is arranged between adjacent battery cells to achieve a shock-absorbing effect. However, the process of arranging the soft material between every two battery cells is very complicated, which is not conducive to the production of a battery pack with multiple battery cells.

[0003] In view of this, it is necessary to provide an improved battery pack to overcome the defects existing in the prior art. Summary of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide a battery pack that uses elastic brackets to fix battery cells, which can reduce the weight of the battery pack and is convenient for assembling the battery cells.

[0005] The technical solution adopted by the utility model to solve the problems of the prior art is: a battery pack, comprising: a battery cell housing; a battery cell assembly, including a plurality of sheet-shaped battery cells arranged in a stacked manner, and the sheet-shaped battery cells are received in the battery cell housing; the battery pack further includes elastic brackets arranged at both longitudinal ends of the battery cell assembly.

[0006] A further improvement is: the elastic bracket includes a first bracket and a second bracket arranged oppositely, and the first bracket and the second bracket at least partially wrap both ends of the battery cell assembly.

[0007] A further improvement is: the sheet-shaped battery cell includes an ear extending outward from the end, and the first bracket is provided with a corresponding first opening, and the ear passes through the first opening.

[0008] A further improvement is: the battery pack includes an adapter plate arranged in the battery cell housing, and the ear is connected to the adapter plate.

[0009] A further improvement is: the adapter plate is provided with a nickel sheet, and the ear is welded to the nickel sheet.

[0010] A further improvement is: the battery pack includes a fixing plate arranged between the first bracket and the adapter plate, the fixing plate is provided with a second opening corresponding to the first opening, and the ear passes through the first opening and the second opening and is connected to the adapter plate.

[0011] A further improvement is: the length of the ear is greater than the sum of the longitudinal height of the first bracket, the thickness of the fixing plate and the thickness of the adapter plate.

[0012] A further improvement scheme is that the fixing plate is made of an elastic material.

[0013] A further improvement scheme is that the second bracket includes a main frame and a partition portion connected to the main frame. The main frame includes side walls surrounded in a circumferential direction. An accommodation space is formed on the inner wall of the side walls. The partition portion divides the accommodation space into a plurality of slots or jacks for inserting the battery cells.

[0014] A further improvement scheme is that the partition portion includes a plurality of partition members. The plurality of partition members are arranged side by side at equal intervals in the accommodation space, and the slots or jacks are formed between adjacent partition members.

[0015] Compared with the prior art, the utility model has the following beneficial effects: The battery pack further includes elastic brackets arranged at the longitudinal two ends of the battery cell assembly. The arrangement of the elastic brackets reduces the weight of the battery pack and facilitates the assembly of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following further describes in detail the specific embodiments of the utility model with reference to the drawings:

[0017] Figure 1 is a schematic structural diagram of the battery pack according to a preferred embodiment of the utility model;

[0018] Figure 2 is Figure 1 a schematic structural diagram of the battery pack shown after removing the battery pack housing;

[0019] Figure 3 is Figure 2 a partial disassembly schematic diagram of the battery pack shown;

[0020] Figure 4 is Figure 3 a disassembly schematic diagram of the elastic bracket and the battery cell assembly in the battery pack shown;

[0021] Figure 5 is Figure 4 a schematic structural diagram of the elastic bracket shown.

[0022] The meanings of the reference numerals in the drawings:

[0023] Battery cell housing 1 End cap 11

[0024] Sheet-like battery cell 21 Tab 22

[0025] Adapter plate 3 Nickel sheet 31

[0026] Fixing plate 4 Second opening portion 41

[0027] Elastic support 5, first support 51

[0028] Second support 52, first opening 53

[0029] Main frame 54, side wall 541

[0030] Receiving space 542, slot / jack 543

[0031] Partition 55, partition member 551

[0032] Gap 56, battery pack housing 6

[0033] First housing 61, second housing 62

[0034] Terminal groove 63, battery pack interface 7

[0035] Guide rail 71, electrical connector 72 Detailed implementation manner

[0036] The terms used in the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. For example, the terms indicating orientation or positional relationship such as "upper", "lower", "front", "rear", etc. are only based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model.

[0037] Please refer to Figures 1 to 5 Shown is a battery pack related to a preferred embodiment of the present utility model, which can be detachably connected to an external device.

[0038] The external device can be an electrical device or a charger. When the battery pack is connected to the electrical device, the battery pack can provide electrical energy for the electrical device. Optionally, the electrical device can be a power tool, a household appliance, etc. The power tool can be a handheld power tool, such as a hammer drill, an electric drill, an angle grinder, etc., or a garden power tool, such as a blower, a chainsaw, a smart lawn mower, etc., and the household appliance can be a vacuum cleaner, a floor washer, a fan, etc. The present utility model does not limit this. When the battery pack is connected to the charger, the charger connected to the power supply can provide electrical energy for the battery pack.

[0039] Please refer to Figure 1 As shown, the battery pack includes a battery pack housing 6 and a battery pack interface 7 for connecting to an external device. The battery pack housing 6 includes a first housing 61 and a second housing 62 that are connected to each other, and the first housing 61 and the second housing 62 are fixed by screws.

[0040] Specifically, the battery pack interface 7 includes a pair of guide rails 71 and an electrical connector 72. The pair of guide rails 71 are arranged on the second housing 62 and are used to guide the mechanical connection between the battery pack and an external device, so that the battery pack can be detachably mounted on the external device. The electrical connector 72 is arranged between the pair of guide rails 71. The electrical connector 72 includes a plurality of battery pack terminals and is used for electrical connection with corresponding terminals of the external device to input or output electric energy. The battery pack housing 6 is provided with a plurality of terminal slots 63, and at least part of the battery pack terminals are received in the terminal slots 63. When the battery pack is connected to the external device, the battery pack terminals are plugged into the corresponding terminals of the external device, thereby realizing the electrical connection between the battery pack and the external device.

[0041] Please refer to Figure 2 and Figure 3 As shown, the battery pack includes a battery cell housing 1 and a battery cell assembly 2 received in the battery pack housing 6. The battery cell housing 1 includes an end cover 11 and a box body. The end cover 11 is fixedly connected to the box body by screws to form an internal space, and the battery cell assembly 2 is received in the internal space formed by the end cover 11 and the box body.

[0042] Specifically, the battery cell assembly 2 includes a plurality of interconnected battery cells, and the battery cells are non-cylindrical battery cells. In this embodiment, the battery cells are sheet-shaped battery cells, and the battery cells can be bent into an arc shape. The battery cell is a sheet-shaped battery cell 21, and a single sheet-shaped battery cell 21 extends along the longitudinal direction. Optionally, the longitudinal direction is set as the up-down direction shown in the figure.

[0043] Furthermore, a plurality of the sheet-shaped battery cells 21 are stacked. Each sheet-shaped battery cell 21 is provided with a tab 22 extending outward from one longitudinal end, and the tab 22 is bent so that adjacent sheet-shaped battery cells 21 overlap and are welded to each other.

[0044] Please refer to Figures 2 to 5 As shown, the battery pack further includes elastic brackets 5 arranged at both longitudinal ends of the battery cell assembly 2. The elastic brackets 5 include a first bracket 51 and a second bracket 52 arranged opposite to each other. The first bracket 51 and the second bracket 52 at least partially wrap both ends of the battery cell assembly 2 respectively, so that both ends of the battery cell assembly 2 can be stably supported inside the battery cell housing 1.

[0045] Specifically, the elastic bracket 5 includes a main frame 54 and a partition part 55 connected to the main frame 54. The main frame 54 and the partition part 55 separate a certain gap 56 between a plurality of sheet-shaped battery cells 21 and there is no filler in the gap 56, so that the sheet-shaped battery cells 21 have good heat dissipation performance on the premise of stable installation. Moreover, there is no direct contact between adjacent sheet-shaped battery cells 21. Therefore, under the support of the elastic bracket 5, the safety performance of the battery pack is improved.

[0046] Further, the main frame 54 includes side walls 541 that are circumferentially arranged. An accommodation space 542 is formed on the inner wall surface of the side walls 541. The partition portion 55 divides the accommodation space 542 into a plurality of slots or sockets 543 for inserting the sheet-shaped battery cells 21. The partition portion 55 includes a plurality of partition members 551. The plurality of partition members 551 are arranged side by side at equal intervals in the accommodation space 542, and slots or sockets 543 are formed between adjacent partition members 551. Slots or sockets 543 are formed between the partition members 551 and the side walls 541. The partition portion 55 includes 4 - 16 partition members 551. The ends of the sheet-shaped battery cells 21 are sequentially inserted into the slots or sockets 543. This installation method improves the convenience of assembling the battery cell assembly 2, thereby improving the installation efficiency of the battery cells.

[0047] After being inserted, at least a part of the battery cell abuts against the partition member 551. The abutting surface between the battery cell and the partition member 551 is a non-smooth plane. Optionally, the abutting surface between the battery cell and the partition member 551 is wavy.

[0048] Specifically, the partition portion 55 and the main frame 54 are made of an elastic material, and the elastic material is foam, silicone, or rubber.

[0049] Please refer to Figure 2 and Figure 3 As shown, the battery pack includes a transfer board 3 and a fixing board 4 disposed in the battery cell housing 1. The transfer board 3 is used to form an electrical connection with the battery cell assembly 2. The sheet-shaped battery cell 21 includes tabs 22 extending outward from the end. The tabs 22 are connected to the transfer board 3, thereby realizing the electrical connection between the battery cell assembly 2 and the transfer board 3.

[0050] Specifically, the first bracket 51 of the elastic bracket 5 is provided with a first opening 53. The tab 22 is connected to the transfer board 3 through the first opening 53. Usually, a nickel sheet 31 is provided on the transfer board 3, and the tab 22 is welded to the nickel sheet 31 of the transfer board 3, improving the reliability of the welding.

[0051] Further, in order to better connect the tab 22 to the transfer board 3, the length of the tab 22 is set to be greater than the sum of the longitudinal height of the first bracket 51, the thickness of the fixing board 4, and the thickness of the transfer board 3. The fixing board 4 is located between the transfer board 3 and the elastic bracket 5 and is made of an elastic material, which is used to prevent the tab 22 from being over-pulled when the battery pack is impacted. The fixing board 4 is also provided with a second opening 41 corresponding to the first opening 53 for the tab 22 to pass through. Optionally, foam can also be provided between the transfer board 3 and the elastic bracket 5 to fill the gap caused by the length of the tab 22, thereby preventing the tab 22 from being damaged and improving the safety performance of the battery pack.

[0052] The energy of a battery refers to the electrical energy output by the battery when doing work externally under certain discharge conditions, and the unit is usually expressed in watt-hours or kilowatt-hours. As the power source of an electric tool, the energy, weight, or volume of the battery pack are two important factors affecting the user experience.

[0053] In this embodiment, the elastic support 5 includes a partition member 551 extending into the gap 56. Among them, the applicant found through research that in the embodiment of this application, when the volume percentage range of the gap 56 in the battery cell assembly 2 is 10%-30%, and the volume percentage range of the battery cell assembly 2 in the battery pack is 60%-70%, the electrical device can not only meet the user's requirements for energy but also meet the user's requirements for the volume of the electrical device, and is conducive to the miniaturization and light weight of the electrical device.

[0054] In the embodiment of this application, the nominal capacity of the sheet-shaped battery cell 21 is 2 Ah - 6 Ah, and the weight energy density range of the sheet-shaped battery cell 21 is 160 - 260 Wh / Kg. In a specific embodiment, when the nominal capacity of the sheet-shaped battery cell 21 is 4 Ah, the weight energy density of the sheet-shaped battery cell 21 is 240 Wh / kg. In a specific embodiment, when the nominal capacity of the sheet-shaped battery cell 21 is 6 Ah, the weight energy density of the sheet-shaped battery cell 21 is 245 Wh / kg.

[0055] The applicant found through research that in the embodiment of this application, the weight energy density range of the battery pack is 160 - 170 Wh / Kg. At this time, under the same weight, the battery pack can provide more energy for the electrical device, thereby improving work efficiency.

[0056] In the embodiment of this application, the sum of the masses of the battery cell assembly 2 and the elastic support 5 accounts for 50% - 60% of the mass of the battery pack, meeting the overall light-weight requirement of the battery pack and improving the user experience during use.

[0057] The greater the voltage of the battery pack, the higher the power of the electrical device. The applicant found that in the embodiment of this application, if it is set that when the voltage of the battery pack is greater than or equal to 35 volts, the working requirements of the electrical device under most working conditions can be met.

[0058] The applicant found through research that in the embodiment of this application, if it is set that when the energy W of the battery pack is greater than or equal to 400 watt-hours, and the mass M1 of the battery pack is less than or equal to 4 kilograms, the electrical device can not only meet the user's requirements for energy but also meet the user's requirements for the mass of the electrical device, and is conducive to the miniaturization and light weight of the electrical device. In a specific embodiment, the energy of the battery pack is 403 watt-hours, and the mass of the battery pack is 2.5 kilograms.

[0059] As a mature energy storage device, it is very difficult to change the structure or manufacturing process of the battery pack. The applicant found that in the embodiments of the present application, when the ratio of the energy W of the battery pack to the mass M1 of the battery pack satisfies: 130 watt-hours per kilogram ≤ W / M1 ≤ 170 watt-hours per kilogram, it can not only meet the user's requirements for miniaturization and light load of the power tool 10, but also will not be difficult to achieve due to overly high requirements. In some embodiments, the ratio of the energy W of the battery pack to the mass M1 of the battery pack can be set to 130.4 watt-hours per kilogram and 161.2 watt-hours per kilogram.

[0060] In the embodiments of the present application, the mass percentage range of the battery cell housing 1 in the battery pack housing 6 is 40% - 50%. In some embodiments, the mass percentage of the battery cell housing 1 in the battery pack housing 6 can be set to 46%.

[0061] In the embodiments of the present application, the volume percentage range of the battery cell assembly 2 and the overall volume of the elastic support 5 in the battery pack is 60% - 70%. In some embodiments, the volume percentage of the battery cell assembly 2 and the overall volume of the elastic support 5 in the battery pack can be set to 66%.

[0062] In the present utility model, the battery pack further includes elastic supports 5 provided at the longitudinal ends of the battery cell assembly 2. The provision of the elastic supports 5 reduces the weight of the battery pack and facilitates the assembly of the battery cells.

[0063] The present utility model is not limited to the above specific embodiments. Those of ordinary skill in the art can easily understand that without departing from the principles and scope of the present utility model, there are many alternative solutions for the battery pack of the present utility model. The protection scope of the present utility model shall be subject to the content of the claims.

Claims

1. A battery pack, comprising: A cell housing; A cell assembly including a plurality of stacked sheet-like cells, and the sheet-like cells are received in the cell housing; Characterized in that, the battery pack further includes elastic brackets disposed at longitudinal ends of the cell assembly, the elastic brackets include a first bracket and a second bracket disposed opposite to each other, the first bracket and the second bracket respectively at least partially wrap both ends of the cell assembly, the second bracket includes a main frame and a partition portion connected to the main frame, the main frame includes a side wall surrounded in a circumferential direction, an accommodation space is formed on an inner wall of the side wall, and the partition portion divides the accommodation space into a plurality of slots or jacks for inserting the cells.

2. The battery pack according to claim 1, wherein, The sheet-like cell includes tabs extending outward from an end portion, and the first bracket is provided with a corresponding first opening, and the tabs pass through the first opening.

3. The battery pack according to claim 2, characterized in that, The battery pack includes an adapter plate disposed in the cell housing, and the tabs are connected to the adapter plate.

4. The battery pack according to claim 3, characterized in that, Nickel sheets are provided on the adapter plate, and the tabs are welded to the nickel sheets.

5. The battery pack according to claim 3, wherein The battery pack includes a fixing plate disposed between the first bracket and the adapter plate, the fixing plate is provided with a second opening corresponding to the first opening, and the tabs pass through the first opening and the second opening and are connected to the adapter plate.

6. The battery pack according to claim 5, wherein The length of the tabs is greater than the sum of the longitudinal height of the first bracket, the thickness of the fixing plate, and the thickness of the adapter plate.

7. The battery pack according to claim 5, characterized in that, The fixing plate is made of an elastic material.

8. The battery pack according to claim 1, characterized in that, The partition portion includes a plurality of partition members, and the plurality of partition members are arranged side by side at equal intervals in the accommodation space, and the slots or jacks are formed between adjacent partition members.

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