Soft package lithium battery module for electric tool

Abstract

The utility model discloses a soft package lithium battery module for an electric tool, and belongs to the technical field of new energy batteries. The soft package lithium battery module comprises a battery cell serving as a power supply end; a positive electrode lug and a negative electrode lug are arranged; the first bracket is provided with a tab slot and a conductive connecting sheet groove; the tab slot is used for a battery cell tab to pass through, the conductive connecting sheet groove is formed in the outer side of the first bracket and is fixedly provided with a conductive connecting sheet in a positioning manner, the conductive connecting sheet is provided with a power supply end butt joint point and a power utilization end butt joint point, and the power supply end butt joint point is electrically connected with the battery cell tab; the second bracket and the first bracket are closed to form a protective shell, and a battery cell accommodating cavity is formed; the battery cells are stacked in the battery cell accommodating cavity along the Y direction, and an adhesive heat conduction pad is arranged between every two adjacent battery cells in the Y direction; the battery cell protection plate is arranged at the top of the protection shell; and a power utilization end butt joint point on the conductive connecting sheet is electrically connected with the battery cell protection plate and penetrates through the battery cell protection plate. The utility model has the advantages of good structural stability, thermal stability, electrical insulation and the like.

Description

Technical Field

[0001] This utility model relates to a technology in the field of new energy batteries, specifically a soft-pack lithium battery module for power tools. Background Technology

[0002] With the widespread use of rechargeable power tools, the battery life and safety of power tool battery packs have become major concerns. Currently, power tools primarily use cylindrical lithium battery modules, which have low overall energy density and large size. Furthermore, conventional cylindrical lithium battery modules cannot dissipate heat evenly, leading to individual cells overheating and failing to register temperature readings. This can cause the protection board to fail to trigger temperature protection, posing a safety risk such as the entire pack exploding. While higher energy density pouch cells are also used to some extent, they are still stacked in the traditional cylindrical lithium battery module manner and then transferred to the protection board via an adapter board. This adapter board transfer increases costs, increases the overall pack size, and makes the structure unstable; given the high vibration levels encountered by power tools, this also presents safety hazards. Utility Model Content

[0003] To address the aforementioned shortcomings of existing technologies, this invention proposes a soft-pack lithium battery module for power tools. The internal cells of the module are stacked in the Y direction, protected by a shell formed by a bracket, and electrically connected through embedded connecting pieces. It can adapt to the vibration conditions of power tools and has advantages such as good structural stability, thermal stability, and electrical insulation.

[0004] This utility model relates to a soft-pack lithium battery module for power tools, comprising:

[0005] Several battery cells serve as the power supply terminals; they are equipped with positive and negative terminals.

[0006] The first bracket has several tab slots and several conductive connecting piece grooves; the tab slots are for the battery cell tabs to pass through, and the conductive connecting piece grooves are located on the outside of the first bracket and are fixed with conductive connecting pieces; the conductive connecting pieces have power supply end docking points and power consumption end docking points, the power supply end docking points are electrically connected to the battery cell tabs, and the power consumption end docking points are used to electrically connect to the power consumption end.

[0007] The second bracket, together with the first bracket, forms a protective shell and a cell housing cavity. The cells are stacked in the cell housing cavity along the Y direction. Adhesive thermal pads are provided between two adjacent cells in the Y direction, which can dissipate heat evenly to each cell, avoid the risk of the whole package exploding due to excessive temperature of individual cells, and improve vibration resistance.

[0008] The cell protection board is located on the top of the protective housing; the conductive connecting piece is electrically connected to the cell protection board by an electrical terminal mating point and passes through the cell protection board.

[0009] In some specific implementation schemes, the protective housing is provided with a spring fixing groove at the top in the Z-axis direction. The spring fixing groove is used to fix the button spring, which is used for the power tool to unlock the battery module.

[0010] In some specific implementation schemes, the first bracket and the second bracket are directly fixedly connected to form a protective shell.

[0011] In some specific implementation schemes, the first bracket and the second bracket are fixedly connected by a third bracket to form a protective shell.

[0012] Preferably, the first bracket, the second bracket, and the third bracket are fixed together by means of snap-fit ​​and slot engagement to improve the structural strength of the protective shell.

[0013] In some specific implementation schemes, the protective shell is surrounded by thermally conductive pads.

[0014] In some specific implementation schemes, in the direction of the tab extension, a supporting foam is provided between the first bracket and the battery cell, which further improves the stability of the battery cell in the battery cell housing cavity.

[0015] Preferably, the soft-pack lithium battery module has an opening at the top in the Z-axis direction for placing a temperature sensor to collect battery temperature information and improve the accuracy of the cell protection board in monitoring the temperature of the entire pack.

[0016] For some specific implementation schemes, corresponding to the electrode slot, the first bracket is provided with an electrode guide groove on the inner side to guide the electrode as it passes through the electrode slot, so as to avoid the electrode being damaged by force and causing leakage.

[0017] In some specific implementations, the conductive connecting piece grooves are either separated from or connected to each other;

[0018] When separated from each other, the conductive connecting piece and the electrode tab have low degree of freedom in electrical connection, the cell connection method is simple, and the overall performance of the cell package is relatively fixed.

[0019] When interconnected, the cells can be connected in different series and parallel ways through the conductive connecting piece, which means that different series and parallel connection methods can share the same shell structure, improving the versatility of lithium battery modules; correspondingly, the first bracket is provided with discontinuous ribs. On the one hand, the ribs form the groove of the conductive connecting piece, and on the other hand, while realizing the high degree of freedom of electrical connection between the conductive connecting piece and the tab, it also realizes electrical insulation to avoid short circuit.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] 1) Compared with the traditional stacking scheme, the Y-axis stacking of cells increases the cell capacity, and the cell expansion direction changes from the Z-axis to the Y-axis;

[0022] 2) The Y-axis stacking of the cells avoids the Z-axis stress damage to the cell protection board caused by the large-area expansion in the thickness direction of the cells;

[0023] 3) The conductive connecting piece directly connects the power supply end and the power consumption end, eliminating the need for the adapter board structure and reducing costs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a power tool battery pack;

[0025] Figure 2 This is an exploded structural diagram of a soft-pack lithium battery module and its bottom shell.

[0026] Figure 3 This is a schematic diagram of a soft-pack lithium battery module without a cell protection board.

[0027] Figure 4 To remove Figure 3 Schematic diagram of the soft-pack lithium battery module structure behind the third bracket in the middle;

[0028] Figure 5 This is a schematic diagram of the first support structure;

[0029] Figure 6 To remove Figure 4 Schematic diagram of the soft-pack lithium battery module structure behind the first bracket in the middle;

[0030] Figure 7 This is a schematic diagram of the Y-axis stacking structure of pouch cells;

[0031] Figure 8 This is a cross-sectional view of the assembly structure of the first, second, and third supports;

[0032] Figure 9 for Figure 8 Enlarged structural diagram at point I;

[0033] Figure 10 for Figure 4 The side view shows the first connection method of the battery cell;

[0034] Figure 11 This is the second connection method for the battery cell;

[0035] In the diagram: 100, First bracket; 101, Top plate; 102, Side plate; 103, Tab slot; 104, Tab guide groove; 105, Guide component; 106, Strip partition; 107, Rib; 200, Second bracket; 300, Third bracket; 301, Spring fixing groove; 302, Button spring; 400, Battery cell; 401, Positive tab; 402, Negative tab; 403, Adhesive thermal pad; 404, Supporting foam; 500, Cell protection board; 600, Conductive connecting piece; 700, Battery pack bottom shell; 800, Soft-pack lithium battery module; 801, Arc-shaped buckle; 802, Protrusion; 803, Cylindrical buckle groove; 804, Recess; 805, Opening; 806, Screw hole; 900, Battery pack top cover. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 1 and Figure 2 As shown, this embodiment relates to a lithium-ion battery pack for power tools, including a battery pack bottom shell 700, a pouch lithium battery module 800, and a battery pack top cover 900. The battery pack bottom shell 700 has raised ribs arrayed on its four side walls, creating a four-walled groove structure with a high level of protection in the Y direction, making the pouch lithium battery module 800 placed inside safer. Preferably, the raised ribs extend in the Z direction, facilitating the placement and removal of the pouch lithium battery module 800.

[0039] like Figures 2 to 7 As shown, the above-mentioned soft-pack lithium battery module 800 includes: a first bracket 100, a second bracket 200, a third bracket 300, a battery cell 400, a battery cell protection board 500, and a conductive connecting piece 600.

[0040] Preferably, there are 10 battery cells 400, each with an exposed positive electrode tab 401 and a negative electrode tab 402. For example... Figure 7 As shown, 10 battery cells 400 are stacked along the Y direction, with the thickness of the cells aligned with the Y direction. An adhesive thermal pad 403 is sandwiched between two adjacent battery cells 400, thus fixing the battery cells 400 together to form a battery cell package that can uniformly generate and dissipate heat, while also reducing the impact of power tool vibration. Even if a single battery cell overheats abnormally, the heat can be quickly conducted, avoiding the risk of the entire package exploding. Based on the above structure, the temperature of the entire battery cell package can be monitored by setting a single temperature acquisition point, improving safety performance.

[0041] like Figure 4 , Figure 8 and Figure 9As shown, preferably, in this embodiment, the first bracket 100 and the second bracket 200 are fixedly connected by a third bracket 300 with a plate-like main body to form a protective shell. The protective shell has a cell receiving cavity, in which the entire cell package is placed. The first bracket 100 and the second bracket 200 are respectively provided with several pairs of two-lobed arc-shaped buckles 801 on the top of the protective shell. The top of the arc-shaped buckle 801 has a protrusion 802 on the outer side. The third bracket is correspondingly provided with a cylindrical buckle groove 803. The cylindrical buckle groove 803 has a concave portion 804 on the top. The cylindrical buckle groove 803 presses the two-lobed arc-shaped buckles 801 on the first bracket 100 and the two-lobed arc-shaped buckles 801 on the second bracket 200 together. The protrusion 803 of the arc-shaped buckle 801 and the concave portion 804 of the cylindrical buckle groove 802 engage with each other to form a stable structure.

[0042] The third bracket 300 has a spring fixing groove 301 at the top in the Z-axis direction. The spring fixing groove 301 is used to fix the button spring 302. The button spring 302 is used to add or unlock the battery module of the power tool.

[0043] The first bracket 100 and the third bracket 300 have an opening 805 on the top of the protective shell, which serves as a temperature acquisition point for placing a temperature sensor to collect battery temperature information, thereby improving the accuracy of the cell protection board 500 in monitoring the temperature of the entire pack.

[0044] The first bracket 100 and the second bracket 200 are also provided with screw holes 806 on the top of the protective housing, and the battery cell protection board 500 is fixed to the protective housing by screws.

[0045] The structure of the first support 100 is as follows: Figure 4 and Figure 5 As shown, it has a top plate 101 and a side plate 102. The side plate 102 is parallel to the Z-axis direction, and the top plate 101 is parallel to the XY horizontal plane.

[0046] Corresponding to the battery cell 400, a corresponding number of electrode tab slots 103 are provided on the side plate 102. In this embodiment, the number of positive and negative electrode tab slots 103 is preferably 10 pairs. The positive electrode tab 401 and the negative electrode tab 402 of the battery cell 400 pass through the corresponding electrode tab slots 103. For any pair of electrodes, the positive electrode tab can be on top or the negative electrode tab can be on top.

[0047] Corresponding to each tab slot 103, the side plate 102 may also be provided with a corresponding tab guide groove 104 on its inner side. The tab guide groove 104 plays a guiding role in the process of the tab passing through the tab slot 103, avoiding the problem of leakage caused by accidental collision and damage during the insertion of the tab. The tab guide groove 104 is composed of guide members 105 arranged on the left and right sides of the tab slot 103 in the Y-axis direction. From the beginning position of the guide to the end position of the guide, the distance between the guide members 105 on the left and right sides of the tab slot 103 decreases. Preferably, the guide members 105 are plate-shaped structures. Two rows of 6 plate-shaped guide members are matched with one tab slot 103. The 3 plate-shaped guide members in the same row are arranged along the Z-axis direction. The two adjacent rows of plate-shaped guide members are separated by strip partitions 106.

[0048] In the direction of tab extension, a support foam 404 is provided between the first bracket 100 and the battery cell 400. On the one hand, it provides a buffer during insertion to further avoid the impact of collision. On the other hand, it further improves the vibration resistance stability of the battery cell in the battery cell housing cavity, especially the vibration resistance stability in the X direction.

[0049] The top plate 101 and the side plate 102 form conductive connecting piece grooves on the outer side by setting discontinuous protrusions 107. Conductive connecting pieces 600 are provided in the conductive connecting piece grooves for connecting the power supply end and the power consumption end.

[0050] A power supply terminal connection point is provided at the beginning of the conductive connecting piece 600. The conductive connecting piece 600 is soldered to the electrode tab at the power supply terminal connection point. The number of electrode tabs can be one, two, three, etc.; when there is more than one, it can be connected in series with both the positive and negative electrode tabs to form a parallel circuit, or it can be connected in parallel with the same electrode tabs to form a series circuit. Figure 10 and Figure 11 These represent two different cell series-parallel connection methods. Figure 10 Ten battery cells are connected in series. Figure 11 The 10 battery cells are first connected in series and then in parallel, with 5 cells forming a group.

[0051] The conductive connecting piece 600 has an electrical end docking point at its end. The electrical end docking point protrudes in the Z-axis direction, passes through the third bracket 300 and the cell protection plate 500 in sequence, and is electrically connected to the cell protection plate 500.

[0052] like Figure 5 and Figure 6As shown, corresponding to the first bracket 100, the second bracket 200 is generally a cuboid frame structure with a top surface and a side surface open parallel to the Y direction, and has a bottom plate and three side plates; the second bracket 200 has ribs on the walls of at least the side plates extending in the Y direction, and these ribs, together with the discontinuous ribs on the first bracket 100, enhance the protection of the battery cell and improve the protection level in the Y direction; preferably, all three side plates are provided with ribs.

[0053] The general assembly process of the soft-pack lithium battery module in this embodiment is as follows:

[0054] First, the battery cells are stacked along the Y direction. The battery cells are bonded and fixed together as a whole with an adhesive thermal pad. Then, they are placed in the second bracket with the tab side exposed on the side.

[0055] Next, push the first bracket along the X-axis until it abuts against the second bracket. During this process, the tab guide groove plays a guiding role in the installation. Then, snap the third bracket in sequence and install the cell protection board.

[0056] Finally, wrap the protective housing with a thermal pad and place it in the bottom shell of the battery pack.

[0057] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A soft-pack lithium battery module for power tools, characterized in that, include: Several battery cells serve as the power supply terminals; they are equipped with positive and negative terminals. The first bracket has several tab slots and several conductive connecting piece grooves; the tab slots are for the battery cell tabs to pass through, and the conductive connecting piece grooves are located on the outside of the first bracket and are fixed with conductive connecting pieces; the conductive connecting pieces have power supply end docking points and power consumption end docking points, the power supply end docking points are electrically connected to the battery cell tabs, and the power consumption end docking points are used to electrically connect to the power consumption end. The second bracket, together with the first bracket, forms a protective shell and a cell housing cavity; the cells are stacked in the cell housing cavity along the Y direction, and an adhesive thermal pad is provided between two adjacent cells in the Y direction. The cell protection board is located on the top of the protective housing; the conductive connecting piece is electrically connected to the cell protection board by an electrical terminal mating point and passes through the cell protection board.

2. The soft-pack lithium battery module according to claim 1, characterized in that, The first bracket is provided with discontinuous ribs to form conductive connecting piece grooves, which are either separated from or connected to each other.

3. The soft-pack lithium battery module according to claim 2, characterized in that, The first bracket and the second bracket are directly fixedly connected to form a protective shell; Alternatively, the first bracket and the second bracket are fixedly connected by a third bracket to form a protective shell; The protective casing has raised ribs on its outer walls to enhance the protection of the battery cell in the Y direction.

4. The soft-pack lithium battery module according to claim 3, characterized in that, The first bracket, the second bracket, and the third bracket are fixed together by means of snap-fit ​​and slot engagement.

5. The soft-pack lithium battery module according to claim 1, 3, or 4, characterized in that, The first bracket and the second bracket are provided with screw holes on the top of the protective housing, and the battery cell protection board is fixed to the protective housing by screws through the screw holes.

6. The soft-pack lithium battery module according to claim 1, characterized in that, The protective shell is surrounded by thermal pads on all four sides.

7. The soft-pack lithium battery module according to claim 1, characterized in that, In the direction where the electrode extends, a supporting foam is provided between the first bracket and the battery cell.

8. The soft-pack lithium battery module according to claim 1, characterized in that, The soft-pack lithium battery module has an opening at the top in the Z-axis direction for placing a temperature sensor to collect battery temperature information.

9. The soft-pack lithium battery module according to claim 1, characterized in that, Corresponding to the electrode slot, the first bracket has an electrode guide groove on its inner side to guide the electrode as it passes through the electrode slot.

10. The soft-pack lithium battery module according to claim 1, characterized in that, The soft-pack lithium battery module is set in the bottom shell of the battery pack, and the bottom shell of the battery pack has convex ridges arrayed on the four side walls, making it a four-walled groove structure.

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