Lithium battery PACK structure

Abstract

The utility model relates to a lithium battery PACK structure which comprises a battery cell support, a battery cell assembly arranged on the battery cell support and a protection circuit board arranged on the side face of the battery cell support and used for managing charging and discharging of the battery cell assembly. The battery cell assembly comprises a plurality of battery cells and a plurality of first connecting sheets connected to positive and negative electrodes of the battery cells, and the protection circuit board is provided with second connecting sheets connected to the first connecting sheets in a one-to-one correspondence manner. According to the lithium battery PACK structure designed by the utility model, the problem that the performance is influenced due to unstable connection between the battery cell and the protection circuit board is solved, and meanwhile, the assembly efficiency is improved.

Description

Technical Field

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

[0002] A lithium battery pack is a power supply device composed of one or more battery cells. A protection circuit board protects and controls the cells. By assembling the battery pack with the main unit, the lithium battery can safely supply power to the device. In existing lithium battery packs, the cells and the protection circuit board are electrically connected via connecting tabs, and the connection points are soldered using a soldering iron. This soldering process is prone to soldering defects such as missing solder or poor solder joints, leading to unstable battery pack performance, frequent short circuits, and low efficiency, thus affecting the overall assembly output of the lithium battery pack. Utility Model Content

[0003] To address the aforementioned problems, the purpose of this invention is to design a lithium battery PACK structure that solves the problem of unstable connection between the battery cell and the protection circuit board, which affects performance, while also improving assembly efficiency.

[0004] The objective of this utility model is achieved through the following technical solution:

[0005] A lithium battery PACK structure includes a cell support, a cell assembly disposed on the cell support, and a protection circuit board disposed on the side of the cell support for managing the charging and discharging of the cell assembly. The cell assembly includes a plurality of cells and a plurality of first connecting pieces connected to the positive and negative terminals of the cells. The protection circuit board is provided with second connecting pieces that are connected to the first connecting pieces one by one.

[0006] The lithium battery pack structure designed in this scheme supports the battery cell assembly through a cell bracket and insulates the battery cell assembly from the protection circuit board. The protection circuit board is located on the side of the cell bracket, rather than at the end of the battery cell assembly. This effectively prevents short circuits caused by abnormal temperature of the protection circuit board, which could melt the insulating gasket of the positive electrode cap and lead to a short circuit. In the event of a cell malfunction, the protection circuit board will block the vent valve of the positive electrode cap, preventing venting and increasing pressure, potentially leading to an explosion and increasing the risk of the battery pack. The battery cells are connected in series or parallel via a first connecting piece, and then connected to the protection circuit board via corresponding second connecting pieces. Specifically, the first connecting piece uses molded nickel sheets, which are resistance welded to the positive and negative electrodes of the battery cell. The second connecting piece uses surface mount nickel strips, which are mounted on the protection circuit board using SMT (Surface Mount Technology). Finally, the first and second connecting pieces are welded together using laser welding, improving connection stability. Furthermore, the use of automated welding replaces manual soldering, improving production and assembly efficiency.

[0007] Furthermore, the battery cell support is provided with receiving grooves that correspond one-to-one with the first connecting piece, and the first connecting piece is embedded in the receiving groove.

[0008] The end of the battery cell bracket has cutouts corresponding to the positive and negative terminals of the battery cell. A receiving groove is provided beside the cutout and is connected to the cutout. The first connecting piece is placed in the receiving groove, with its end that connects to the positive and negative terminals of the battery cell extending into the cutout for easy welding. The surface of the first connecting piece is not higher than the surface of the battery cell bracket, thus preventing the first connecting piece from protruding and effectively preventing welding failure between the first connecting piece and the positive and negative terminals of the battery cell due to impact.

[0009] Furthermore, the first connecting piece is provided with a first connecting end extending toward the protective circuit board, the second connecting piece is provided with a second connecting end and a third connecting end, the first connecting end is welded to the second connecting end, and the third connecting end is attached to the protective circuit board.

[0010] The second connecting piece is mounted on the protection circuit board using SMT surface mount technology. The third connecting end of the second connecting piece is connected to the solder joint on the protection circuit board to achieve electrical conduction. The first connecting end of the first connecting piece is attached to the second connecting end of the second connecting piece and connected by laser welding. The welding strength is high, the solder joint position can be precisely controlled, and the current transmission stability is ensured.

[0011] Furthermore, the battery cell support includes a first support and a second support, which together form a cavity for accommodating the battery cell, and a battery cell slot corresponding to each battery cell is provided in the cavity.

[0012] By designing cell slots that correspond one-to-one with the cells, stable support is provided for the cells. After the cells are assembled into the cell slots, they are separated from each other, forming a natural convection channel, which can improve heat dissipation.

[0013] Furthermore, the first bracket has buckle grooves on both sides in the width direction, and the second bracket has buckle protrusions corresponding to the buckle grooves.

[0014] The first bracket and the second bracket are connected by a snap-fit ​​structure consisting of snap-fit ​​grooves and snap-fit ​​protrusions, which achieves one-click snap-fit ​​connection. Through the elastic deformation and mechanical engagement of the snap-fit ​​structure, the connection is stable and the assembly efficiency is high. At the same time, it can be quickly disassembled and easy to replace parts.

[0015] Furthermore, a limiting protection protrusion is provided on the side of the buckle protrusion.

[0016] The limiting protection protrusions are located on both sides of the buckle protrusion. After the buckle groove and the buckle protrusion are engaged, the limiting protection protrusions are located on both sides of the buckle groove, which plays a protective role and can prevent the buckle groove from being damaged by external force, thus preventing the connection between the buckle groove and the buckle protrusion from failing.

[0017] Furthermore, the first bracket is provided with a first locking hole, and the second bracket is provided with a second locking hole corresponding to the first locking hole.

[0018] In addition, to further enhance the stability of the connection between the first bracket and the second bracket, corresponding first locking holes and second locking holes are provided between the first bracket and the second bracket. After the first bracket and the second bracket are closed, the first locking holes and the second locking holes are connected and screwed together by threaded fasteners.

[0019] Furthermore, the side of the battery cell bracket that is attached to the protective circuit board is provided with positioning posts and mounting holes, and the protective circuit board is provided with positioning holes corresponding to the positioning posts and connection holes corresponding to the mounting holes.

[0020] The protection circuit board is locked onto the cell bracket by threaded fasteners. Specifically, the protection circuit board and the cell bracket are precisely positioned by a positioning structure consisting of positioning holes and positioning posts, so that the connection hole of the protection circuit board is connected to the mounting hole of the cell bracket, and then the two are screwed together by threaded fasteners.

[0021] Furthermore, a heat shrink tubing is fitted onto the outer side of the protective circuit board.

[0022] After the protection circuit board is assembled, heat shrink tubing is fitted onto the outside of the protection circuit board. It is then heated and shrunk to adhere to the surface of the protection circuit board and the cell support, thus encasing the protection circuit board and the cell support and providing physical protection and electrical isolation. After heat shrinking, the heat shrink tubing has a smooth appearance without wrinkles or sharp corners. While providing protection, it can effectively reduce the size of the battery pack packaging and is also relatively inexpensive.

[0023] Compared with the prior art, the beneficial effects of this utility model are:

[0024] The lithium battery pack structure designed in this scheme supports the battery cell assembly through a cell bracket and insulates the battery cell assembly from the protection circuit board. The protection circuit board is located on the side of the cell bracket, rather than at the end of the battery cell assembly. This effectively prevents short circuits caused by abnormal temperature of the protection circuit board, which could melt the insulating gasket of the positive electrode cap and lead to a short circuit. In the event of a cell malfunction, the protection circuit board will block the vent valve of the positive electrode cap, preventing venting and increasing pressure, potentially leading to an explosion and increasing the risk of the battery pack. The battery cells are connected in series or parallel via a first connecting piece, and then connected to the protection circuit board via corresponding second connecting pieces. Specifically, the first connecting piece uses molded nickel sheets, which are resistance welded to the positive and negative electrodes of the battery cell. The second connecting piece uses surface mount nickel strips, which are mounted on the protection circuit board using SMT (Surface Mount Technology). Finally, the first and second connecting pieces are welded together using laser welding, improving connection stability. Furthermore, the use of automated welding replaces manual soldering, improving production and assembly efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a lithium battery PACK structure (without heat shrink tubing) according to an embodiment of the present invention.

[0026] Figure 2 This is an exploded view of the lithium battery PACK structure according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of a battery cell support according to an embodiment of the present invention.

[0028] Figure 4 An explosion of a battery cell support according to an embodiment of this utility model. Figure 1 .

[0029] Figure 5 An explosion of a battery cell support according to an embodiment of this utility model. Figure 2 .

[0030] Illustrations: 1. Battery cell bracket; 11. Receiving groove; 12. First bracket; 13. Second bracket; 14. Cavity; 15. Battery cell slot; 16. Positioning post; 17. Mounting hole; 121. Snap-fit ​​protrusion; 122. First locking hole; 131. Snap-fit ​​protrusion; 132. Limit protection protrusion; 133. Second locking hole; 2. Battery cell assembly; 21. Battery cell; 22. First connecting piece; 221. First connecting end; 3. Protective circuit board; 31. Second connecting piece; 32. Positioning hole; 33. Connecting hole; 311. Second connecting end; 312. Third connecting end; 4. Heat shrink tubing. Detailed Implementation

[0031] To facilitate understanding of this invention, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0032] like Figures 1 to 5 As shown, this embodiment provides a lithium battery PACK structure, including a cell support 1, a cell assembly 2 disposed on the cell support 1, and a protection circuit board 3 disposed on the side of the cell support 1 for managing the charging and discharging of the cell assembly 2. The cell assembly 2 includes multiple cells 21. The cell support 1 includes a first support 12 and a second support 13, which together form a cavity 14 for accommodating the cells 21. Cell slots 15, corresponding one-to-one with the cells 21, are provided within the cavity 14. In this embodiment, the cell assembly 2 includes four cells 21, and correspondingly, four cell slots 15 are provided. By designing cell slots 15 that correspond one-to-one with the cells 21, stable support is provided for the cells 21. After the cells 21 are assembled into the cell slots 15, they are separated from each other, forming natural convection channels, which improves heat dissipation. The first support 12 has snap-fit ​​protrusions 121 on both sides in the width direction, and the second support 13 has snap-fit ​​protrusions 131 corresponding to the snap-fit ​​protrusions 121. The first bracket 12 and the second bracket 13 are connected by a snap-fit ​​structure consisting of a snap-fit ​​groove 121 and a snap-fit ​​protrusion 131, achieving a one-click connection. Through the elastic deformation and mechanical engagement of the snap-fit ​​structure, the connection is stable and assembly efficiency is high, while also allowing for quick disassembly and easy component replacement. Two limiting protection protrusions 132 are also provided on the sides of the snap-fit ​​protrusion 131. These limiting protection protrusions 132 are located on both sides of the snap-fit ​​protrusion 131. After the snap-fit ​​groove 121 and the snap-fit ​​protrusion 131 are engaged, the limiting protection protrusions 132 remain on both sides of the snap-fit ​​groove 121, providing protection against damage to the snap-fit ​​groove 121 caused by external impact, which could lead to connection failure between the snap-fit ​​groove 121 and the snap-fit ​​protrusion 131. In addition, in order to further enhance the stability of the connection between the first bracket 12 and the second bracket 13, corresponding first locking holes 122 and second locking holes 133 are provided between the first bracket 12 and the second bracket 13. After the first bracket 12 and the second bracket 13 are closed, the first locking holes 122 and the second locking holes 133 are connected and screwed together by threaded fasteners.

[0033] like Figure 2As shown, the battery cell assembly 2 also includes a first connecting piece 22. The first connecting piece 22 is made of molded nickel sheet. The four battery cells 21 are connected in series through five first connecting pieces 22. Specifically, the ends of the first bracket 12 and the second bracket 13 are provided with cutouts corresponding to the positive and negative poles of the battery cells 21. After the battery cells 21 are installed in the battery cell bracket 1, the positive and negative poles of the battery cells 21 correspond to the cutout positions of the first bracket 12 and the second bracket 13. A receiving groove 11 is provided on the side of the cutout. The receiving groove 11 corresponds one-to-one with the first connecting piece 22. The receiving groove 11 is connected to the cutout. The first connecting piece 22 is set in the receiving groove 11, and its end connected to the positive and negative poles of the battery cells 21 extends into the cutout position. The first connecting piece 22 is welded to the positive and negative poles of the battery cells 21 by resistance welding process. The first connecting piece 22 is placed in the receiving groove 11, and its surface is not higher than the surface of the cell support 1, thereby avoiding the first connecting piece 22 from protruding and effectively preventing the welding failure between the first connecting piece 22 and the positive and negative poles of the cell 21 due to bumps.

[0034] like Figure 1 and Figure 2 As shown, the side of the battery cell bracket 1 that is attached to the protection circuit board 3 is provided with a positioning post 16 and a mounting hole 17. The protection circuit board 3 is provided with a positioning hole 32 corresponding to the positioning post 16 and a connection hole 33 corresponding to the mounting hole 17. The protection circuit board 3 is locked onto the battery cell bracket 1 by threaded fasteners. Specifically, the positioning structure composed of the positioning hole 32 and the positioning post 16 achieves precise positioning between the protection circuit board 3 and the battery cell bracket 1, so that the connection hole 33 of the protection circuit board 3 is connected to the mounting hole 17 of the battery cell bracket 1, and then the two are screwed together by threaded fasteners. The protection circuit board 3 is provided with a second connecting piece 31 that is connected to the first connecting piece 22. The first connecting piece 22 is provided with a first connecting end 221 extending toward the protection circuit board 3. The second connecting piece 31 is provided with a second connecting end 311 and a third connecting end 312. The second connecting piece 31 is made of surface mount nickel strip and is mounted on the protection circuit board 3 by SMT surface mount technology. The third connecting end 312 of the second connecting piece 31 is connected to the solder joint on the protection circuit board 3 to achieve electrical conduction. The first connecting end 221 of the first connecting piece 22 and the second connecting end 311 of the second connecting piece 31 are attached to each other and connected by laser welding. The welding strength is high, the solder joint position can be precisely controlled, and the current transmission stability is ensured.

[0035] In this embodiment, the battery cell assembly includes four battery cells. In other possible embodiments, the number of battery cells may be adapted and is not specifically limited here.

[0036] like Figure 2As shown, after the protection circuit board 3 is assembled, a heat shrink tube 4 is fitted on the outside of the protection circuit board 3. It is then heated and shrunk to adhere to the surface of the protection circuit board 3 and the cell support 1, thus wrapping the protection circuit board 3 and the cell support 1 inside, providing physical protection and electrical isolation. After the heat shrink tube 4 is heat-shrinked, it has a smooth appearance without wrinkles or sharp corners. While providing protection, it can effectively reduce the volume of the battery pack packaging and has a low cost.

[0037] In this embodiment, the lithium battery PACK structure supports the cell assembly 2 through the cell bracket 1 and insulates the cell assembly 2 from the protection circuit board 3. At the same time, the protection circuit board 3 is located on the side of the cell bracket 1, rather than at the end of the cell assembly 2. This can effectively prevent the insulation gasket of the positive cap of the cell 21 from melting due to abnormal temperature of the protection circuit board 3 and short circuit fire, which would cause the cell 21 to short circuit. When the cell 21 is abnormal, the protection circuit board 3 will block the vent valve of the positive cap of the cell 21. The cell 21 cannot vent, and the increased pressure will lead to an explosion, increasing the danger of the battery pack. The battery cells 21 are connected in series or in parallel through the first connecting piece 22, and then connected to the protection circuit board 3 through corresponding second connecting pieces 31. Specifically, the first connecting piece 22 is a molded nickel sheet, which is welded to the positive and negative terminals of the battery cell 21 by resistance welding. The second connecting piece 31 is a surface mount nickel strip, which is mounted on the protection circuit board 3 by SMT surface mount technology. Finally, the first connecting piece 22 and the second connecting piece 31 are welded by laser welding to improve the stability of the connection. At the same time, the automated welding method replaces the manual soldering method, improving the production and assembly efficiency.

[0038] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0039] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, the inclusion of "first," "second," etc., in a feature may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A lithium battery PACK structure, characterized by, The battery cell holder, the battery cell assembly arranged on the battery cell holder, and the protection circuit board arranged on the side of the battery cell holder for managing the charging and discharging of the battery cell assembly, the battery cell assembly comprises a plurality of battery cells and a plurality of first connecting pieces connected to the positive and negative poles of the battery cells, and the protection circuit board is provided with a plurality of second connecting pieces corresponding to the first connecting pieces.

2. The lithium battery PACK structure according to claim 1, characterized by, The battery cell holder is provided with a plurality of accommodating grooves corresponding to the first connecting pieces, and the first connecting pieces are embedded in the accommodating grooves.

3. The lithium battery PACK structure according to claim 1, characterized by, The first connecting piece comprises a first connecting end extending towards the protection circuit board, the second connecting piece comprises a second connecting end and a third connecting end, the first connecting end is welded to the second connecting end, and the third connecting end is attached to the protection circuit board.

4. The lithium battery PACK structure according to claim 1, characterized by, The battery cell holder comprises a first holder and a second holder, the first holder and the second holder form a cavity for accommodating the battery cells, and the cavity is provided with a plurality of battery cell grooves corresponding to the battery cells.

5. The lithium battery PACK structure according to claim 4, characterized by, The first holder is provided with a buckle protruding groove on both sides in the width direction, and the second holder is provided with a buckle protruding piece corresponding to the buckle protruding groove.

6. The lithium battery PACK structure according to claim 5, characterized by, The side of the buckle protruding piece is further provided with a limiting protection protruding piece.

7. The lithium battery PACK structure according to claim 4, characterized by, The first holder is provided with a first locking hole, and the second holder is provided with a second locking hole corresponding to the first locking hole. 8.The lithium battery PACK structure according to claim 1, characterized in that, The side of the battery cell holder attached to the protection circuit board is provided with a positioning column and a mounting hole, the protection circuit board is provided with a positioning hole corresponding to the positioning column and a connecting hole corresponding to the mounting hole. 9.The lithium battery PACK structure according to claim 1, characterized in that, The outer side of the protection circuit board is provided with a heat shrink tube.

Images