Busbar, battery module and battery pack

Abstract

The utility model discloses a busbar, battery module and battery pack, the busbar includes at least two conducting strip, by setting the first weak part and the second weak part above the thinning area, when the pressure is released, the thinning area will be burst open by the high pressure gas in the single battery, and the impact force will break the first weak part and the second weak part. Therefore, the pressure release valve can efficiently and smoothly release pressure; and when the first weak part and the second weak part are disconnected, the circuit connection between the two adjacent single batteries is also disconnected, so that short-circuit protection is realized, and finally, dual protection of pressure relief protection and battery cell short-circuit protection is synchronously realized. In addition, the first weak part and the second weak part are fused due to overcurrent when being subjected to strong current, and dual protection can also be achieved. The battery module with the busbar can realize dual protection of internal pressure relief protection and battery cell short-circuit protection of the battery module. The battery pack with the battery module has higher safety performance.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a bus bar, a battery module and a battery pack. Background Art

[0002] In the field of cylindrical batteries, in order to increase the output voltage or current of the battery, a bus is usually used to connect several single cells in series and / or in parallel to form a battery module. For this purpose, the bus can transmit the electrical energy generated by all single cells to the output port of the battery module for use by external devices. The bus can also evenly distribute the electrical energy differences between the single cells, thereby improving the service life and performance of the entire battery module.

[0003] In the cylindrical battery module, the pressure relief valve of the single cell is designed on the same side as its positive and negative electrodes, and the busbar connects the positive and negative electrodes of multiple single cells in series and in parallel by welding. This structure has a technical defect: when the pressure relief valve needs to release pressure, the busbar will affect the pressure relief efficiency of the pressure relief valve, resulting in a slower pressure relief efficiency of the pressure relief valve. When a large amount of heat is released inside the single cell, the heat inside the single cell under this structure cannot be quickly discharged, and the surrounding single cells are prone to heat surges, causing continuous thermal runaway reactions, damaging the entire battery module. In addition, when a short circuit occurs in the single cell itself, the busbar design under this structure cannot provide timely and effective short-circuit protection. Utility Model Content

[0004] In order to overcome at least one of the defects described in the above-mentioned prior art, one of the purposes of the utility model is to provide a busbar, which can improve the pressure relief efficiency of the pressure relief valve and at the same time timely realize short-circuit protection between single cells, thereby realizing pressure relief protection and short-circuit protection when the battery is abnormal.

[0005] The second purpose of the utility model is to provide a battery module, which can improve the efficient pressure relief of the pressure relief valve on the single battery and can also timely realize the short circuit protection between the single batteries, thereby realizing the dual protection of the battery module.

[0006] The third purpose of the utility model is to provide a battery pack, which can ensure that the pressure relief valve on the single battery can release pressure efficiently, and can also ensure short-circuit protection between the single batteries in time, thereby realizing double protection of the battery.

[0007] One of the technical solutions adopted by the utility model to solve the problem is:

[0008] A busbar, used for connecting a plurality of single cells in series and / or in parallel, comprises at least two conductive sheets, each conductive sheet comprising a positive electrode welding portion and a negative electrode welding portion;

[0009] A first weak portion is provided at the connection between the positive electrode welding portions of two adjacent conductive sheets, and a second weak portion is provided at the connection between the positive electrode welding portion and the negative electrode welding portion of each conductive sheet;

[0010] In each of the conductive sheets, the positive electrode welding portion is connected to the positive electrode of the single cell, and the negative electrode welding portion is connected to the negative electrode of an adjacent single cell;

[0011] In each of the single cells, a pressure relief valve is provided at the positive electrode thereof, and the pressure relief valve is provided with a thinned area for bursting when the pressure is released, and the first weak portion and the second weak portion are respectively located above the thinned area, and the first weak portion and the second weak portion are broken by a strong impact force when the thinned area bursts, and / or the first weak portion and the second weak portion are melted due to overcurrent when subjected to a strong current.

[0012] By arranging the first weak part and the second weak part of the busbar above the thinned area, when the pressure relief valve releases pressure, the thinned area will be first opened by the high-pressure gas in the single cell, and at the same time, the strong impact force of the rapid opening of the pressure relief valve will break the first weak part and the second weak part, so that the pressure relief valve can release pressure efficiently without being affected by the obstruction of the busbar; and when the first weak part and the second weak part are disconnected, the circuit connection loop between the two adjacent single cells will also be disconnected, so that even if a short circuit occurs between the single cells, short circuit protection can be carried out in time, and finally the dual protection of internal pressure relief protection when the single cell is abnormal and the short circuit protection of the battery cells between the single cells is realized simultaneously, providing enhanced protection for the thermal safety and electrical safety operation of the battery. In addition, the first weak part and the second weak part will also be melted due to overcurrent when subjected to strong current, which can also achieve the purpose of dual protection, realizing the internal pressure relief protection when the single cell is abnormal and the short circuit protection of the battery cells between the single cells.

[0013] Furthermore, the positive electrode welding portion and the negative electrode welding portion of each of the conductive sheets are respectively connected to the positive electrode and the negative electrode of two adjacent single batteries, so that the two adjacent single batteries are connected in series and form a battery unit; the two adjacent battery units are connected through the positive electrode welding portions of the two conductive sheets thereon to achieve parallel connection of the two adjacent battery units; a first connecting strip is provided at the connection between the positive electrode welding portions of the two conductive sheets on the two adjacent battery units, and the first weak portion is provided on the first connecting strip.

[0014] In order to ensure the connection strength between two adjacent conductive sheets and facilitate the transportation and installation of the busbar, the technical solution provides a first connecting strip between the positive electrode welding parts of two adjacent conductive sheets. The first connecting strip can also carry large currents and reduce electrical losses.

[0015] Furthermore, two first weak portions are provided, and the two first weak portions are respectively provided at two ends of the first connecting strip and close to the corresponding positive electrode welding portion, and the two first weak portions are respectively opposite to the thinning areas of two adjacent pressure relief valves.

[0016] The technical solution adopts two first weak parts, and the two first weak parts are respectively opposite to the thinned areas of two adjacent pressure relief valves. When any pressure relief valve is opened for pressure relief, the connection between the two adjacent conductive sheets can be independently broken, thereby ensuring efficient pressure relief of the pressure relief valve and realizing circuit short-circuit protection.

[0017] Furthermore, the first weak portion is a connecting piece provided with a first notch.

[0018] Furthermore, the first notch is located in the middle of the connecting piece.

[0019] Furthermore, the connecting piece forms breakable portions on both sides of the first notch, and the sum of the cross-sectional areas of the two breakable portions is not greater than the cross-sectional area of ​​the first notch.

[0020] Furthermore, the width of the breakable portion is a, the width of the connecting piece is b, and the ratio of a / b is in the range of 0.12-0.15.

[0021] The first notch of the technical solution reduces the cross-section of the connecting piece, making it easier for the first weak portion to be cut off by the opened pressure relief valve. When the first notch is located in the middle of the connecting piece, the first notch is a through hole, and the connecting piece forms breakable portions on both sides of the first notch, and the cross-section of the breakable portions is much smaller than the cross-sectional area of ​​the first notch, making it easier for the first weak portion to be cut off by the opened pressure relief valve.

[0022] Furthermore, in a single conductive sheet, its positive electrode welding portion and its negative electrode welding portion are connected via a second connecting strip, and the second weak portion is provided on the second connecting strip, and the second weak portion is close to the positive electrode welding portion.

[0023] The technical solution sets a second connecting strip to enhance the connection strength between the positive electrode welding part and the negative electrode welding part in each conductive sheet. When the battery is subjected to its own expansion force or external force impact, the second connecting strip can be deformed accordingly to avoid disconnection of the second weak part.

[0024] Furthermore, the second weak portion is a connecting piece with a second notch.

[0025] Furthermore, the second notch is located in the middle of the connecting piece, and the connecting piece forms breakable portions on both sides of the second notch, and the cross-sectional area of ​​the breakable portions is much smaller than the cross-sectional area of ​​the second notch.

[0026] Furthermore, the width of the breakable portion is a, the width of the connecting piece is b, and the ratio of a / b is in the range of 0.073-0.077.

[0027] The second notch of the technical solution reduces the cross-section of the connecting piece. When the second notch is located in the middle of the connecting piece, the second notch is a through hole. The connecting piece forms breakable portions on both sides of the second notch, and the cross-section of the breakable portions is much smaller than the cross-sectional area of ​​the second notch, so that the second weak portion is more easily broken by the opened pressure relief valve.

[0028] Furthermore, the second connecting strip is provided with a buffer step, the positive electrode welding portion and the second weak portion are both located on the upper step surface of the buffer step, the negative electrode welding portion is located on the lower step surface of the buffer step, and the upper step surface is connected to the lower step surface via an inclined surface.

[0029] The buffer step setting of the present technical solution can, firstly, match the height difference between the positive electrode and the negative electrode, so that the positive electrode welding part can fit with the upper surface of the positive electrode, and the negative electrode welding part can fit with the upper surface of the negative electrode; secondly, it can provide a buffer for the slight relative movement between two adjacent single cells to avoid deformation or breakage of the second weak part.

[0030] Furthermore, the height difference between the upper step surface and the lower step surface is 1-2 mm.

[0031] Furthermore, the negative electrode of the single battery is an annular surface, and the negative electrode welding part is provided with an inwardly concave arc surface matching with the annular surface; the positive electrode of the single battery is a circular pole, and the positive electrode welding part is a circular surface matching with the circular pole.

[0032] The negative electrode welding part of the technical solution is provided with an inwardly concave arc surface, which can firstly increase the welding area with the negative electrode and enhance the connection strength, and secondly avoid the pressure relief valve to prevent the negative electrode welding part from covering the thinning area of ​​the pressure relief valve, thereby causing the pressure relief valve to fail to open normally. The circular surface of the positive electrode welding part cooperates with the circular pole of the positive electrode to enhance the connection strength.

[0033] Furthermore, the positive electrode welding portion is provided with a positioning through hole for welding connection with the positive electrode of the single battery.

[0034] The positioning through hole of the present technical solution is conducive to finding the positive electrode when laser welding the positive electrode welding part and the positive electrode, thereby achieving welding accuracy.

[0035] Furthermore, the pressure relief valve is arranged around the positive electrode, and when the pressure is released, the positive electrode falls off along with the falling off of the pressure relief valve.

[0036] Furthermore, the negative electrode of the single cell is arranged around the pressure relief valve, and the thinned area is arranged close to the negative electrode.

[0037] The second technical solution adopted by the utility model to solve the problem is:

[0038] A battery module comprises a plurality of single cells and the busbar, wherein the busbar connects the plurality of single cells in series and / or in parallel via the conductive sheet.

[0039] Furthermore, the positive electrode welding part and the negative electrode welding part of the conductive sheet are respectively connected to the positive electrode and the negative electrode of two adjacent single batteries, so that the two adjacent single batteries are connected in series to form a battery unit; the two adjacent battery units are connected through the positive electrode welding parts of the two adjacent conductive sheets to achieve parallel connection of the two adjacent battery units.

[0040] Furthermore, the second notch is a glue leakage hole, and two adjacent single batteries are bonded together by adhesive injected from the glue leakage hole.

[0041] The third technical solution adopted by the utility model to solve the problem is:

[0042] A battery pack comprises the battery module.

[0043] The busbar provided by the utility model has the following technical effects:

[0044] By arranging the first weak part and the second weak part of the busbar above the thinned area, when the pressure relief valve releases pressure, the thinned area will be first opened by the high-pressure gas in the single cell, and at the same time, the strong impact force of the rapid opening of the pressure relief valve will break the first weak part and the second weak part, so that the pressure relief valve can release pressure efficiently without being hindered by the busbar. When the first weak part and the second weak part are disconnected, the circuit connection loop between the two adjacent single cells will also be disconnected, so that even if a short circuit occurs between the single cells, short circuit protection can be carried out in time, and finally the dual protection of internal pressure relief protection when the single cell is abnormal and battery short circuit protection is achieved simultaneously, providing enhanced protection for the thermal safety and electrical safety operation of the battery. In addition, the first weak part and the second weak part will also be melted due to overcurrent when subjected to strong current, which can also achieve the purpose of dual protection, realizing internal pressure relief protection when the single cell is abnormal and battery short circuit protection between the single cells.

[0045] The battery module provided by the utility model has the above-mentioned bus bar. By arranging the first weak portion and the second weak portion of the bus bar opposite to the thinning area, the pressure relief valve can efficiently relieve pressure and disconnect the circuit connection loop between two adjacent single cells, so that even if a short circuit occurs between the single cells or within the battery module, short-circuit protection can be carried out in time, and finally the dual protection of internal pressure relief protection and battery cell short-circuit protection of the battery module is realized simultaneously, thereby improving the thermal safety and electrical safety operation performance of the battery module; in addition, the first weak portion and the second weak portion will also be melted due to overcurrent when subjected to strong current, and the dual protection of pressure relief protection and short-circuit protection can also be achieved.

[0046] The battery pack provided by the utility model has the above-mentioned battery module, which can ensure that the pressure relief valve can efficiently relieve pressure and at the same time disconnect the circuit connection loop between two adjacent single cells, so that even if a short circuit occurs between the single cells or in the battery module or battery pack, short-circuit protection can be performed in time, and finally the dual protection of internal pressure relief protection and cell short-circuit protection of the battery pack is realized simultaneously, thereby improving the thermal safety and electrical safety operation performance of the battery pack; in addition, the first weak portion and the second weak portion will also be melted due to overcurrent when subjected to strong current, and the dual protection of pressure relief protection and short-circuit protection can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the main structure of the busbar of the utility model;

[0048] Figure 2 It is a three-dimensional structural schematic diagram of the busbar of the utility model;

[0049] Figure 3 for Figure 2 A schematic diagram of the local enlarged structure at point A in the middle;

[0050] Figure 4 It is a schematic diagram of the main structure of the busbar of the utility model when the first weak part and the second weak part are both disconnected;

[0051] Figure 5 It is a schematic diagram of the three-dimensional structure of the busbar of the utility model when the first weak part and the second weak part are both disconnected;

[0052] Figure 6 It is a schematic diagram of the structure of a single cell of the utility model;

[0053] Figure 7 This is a schematic diagram of the main structure of a busbar of the utility model that connects multiple single cells in series and parallel;

[0054] Figure 8 It is a three-dimensional structural schematic diagram of a busbar of the utility model that connects a plurality of single cells in series and parallel;

[0055] Fig. 9 It is a schematic diagram of the front view structure of the battery module of the utility model when the first weak part and the second weak part are partially disconnected;

[0056] Fig.10 It is a schematic diagram of the three-dimensional structure when the first weak part and the second weak part of the battery module of the utility model are partially disconnected.

[0057] The meanings of the reference numerals are as follows:

[0058] 1. Single cell, 11. Positive electrode, 12. Negative electrode, 13. Pressure relief valve, 131. Thinning area;

[0059] 2. conductive sheet, 21. positive electrode welding portion, 210. positioning through hole, 22. negative electrode welding portion, 220. arc surface;

[0060] 23. first connecting strip, 230. first weak portion, 2301. first notch, 2302. first easily breakable portion;

[0061] 24. second connecting strip, 240. second weak portion, 2401. second notch, 2402. second breakable portion,

[0062] 25, buffer step, 250, upper step surface, 251, lower step surface, 252, inclined surface;

[0063] 26. Process positioning holes. DETAILED DESCRIPTION

[0064] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0065] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0067] See also Figure 1 and Figure 2 The utility model discloses a busbar, which is used to connect a plurality of single cells 1 in series and / or in parallel, and then several single cells 1 can be connected in series and / or in parallel to form a battery module, see Figure 7 and Figure 8 The busbar can transmit the electric energy generated by all the single cells 1 to the output port of the battery module for use by external devices.

[0068] In this embodiment, see Figure 6 As shown, the single cell 1 is a cylindrical power battery, and the single cell 1 is provided with a positive electrode 11, a negative electrode 12 and a pressure relief valve 13, and the positive electrode 11, the negative electrode 12 and the pressure relief valve 13 on the single cell 1 are all located on the same end surface of the single cell 1, so as to facilitate the busbar to connect multiple single cells 1 in series and in parallel. Specifically, the positive electrode 11 of the single cell 1 is a positive electrode column, the pressure relief valve 13 is arranged around the positive electrode 11, and the negative electrode 12 is arranged around the pressure relief valve 13, and the positive electrode 11, the negative electrode 12 and the pressure relief valve 13 of the single cell 1 are all arranged coaxially. Since the positive electrode 11 of the single cell 1 is a positive electrode column, the upper surface of the positive electrode column is higher than the upper surface of the negative electrode 12 and the pressure relief valve 13 of the single cell 1, and this height difference facilitates the busbar to connect the positive electrode column and the negative electrode 12 respectively, and it is not easy to cause a short circuit between the positive and negative electrodes in the single cell 1. In some embodiments, the single cell 1 may also be a square cell or a rectangular cell, or other shaped cells, and the shape of the single cell 1 is not limited; when the single cell 1 may also be a square cell or a rectangular cell, the pressure relief valve 13 may be disposed on the positive electrode 11, without being limited by the position of the negative electrode 12. In some embodiments, the pressure relief valve 13 may be a pressure relief device such as a safety valve, a pressure release valve, or an explosion-proof valve.

[0069] See also Figure 6As shown, the positive electrode 11 and the pressure relief valve 13 of the single cell 1 are designed together. The positive electrode 11 and the pressure relief valve 13 of the single cell 1 can be an assembled structure or an integrally formed structure. When the pressure relief valve 13 is opened for pressure relief, the pressure relief valve 13 falls off from the single cell 1, and the positive electrode 11 falls off along with the pressure relief valve 13. When the internal pressure of the single cell 1 reaches the maximum pressure at which the pressure relief valve 13 is opened, in order to enable the pressure relief valve 13 to open smoothly, the pressure relief valve 13 is provided with a thinning area 131 for bursting during pressure relief, and the thinning area 131 is arranged in an annular shape, and the thinning area 131 is arranged close to the negative electrode 12, so as to maximize the opening area of ​​the pressure relief valve 13, facilitate rapid pressure relief, and improve safety performance. Among them, the thinned area 131 is the pressure relief notch of the pressure relief valve 13. The pressure relief notch is a preset weak area. The pressure relief notch will rupture when it reaches or exceeds a predetermined pressure. The pressure relief notch can be a groove, a cut, a weakened line or other forms of structure. The depth, width and shape of the pressure relief notch can be set according to actual conditions. It only needs to ensure that it ruptures under a predetermined pressure. In some embodiments, when the pressure relief valve 13 is opened for pressure relief, the positive electrode 11 may not fall off the single battery 1. At this time, the thinned area 131 of the pressure relief valve 13 needs to be additionally added, and the additional thinned area 131 needs to be close to the positive electrode 11, so that when the pressure relief valve 13 is opened for pressure relief, the two thinned areas 131 of the pressure relief valve 13 will burst open.

[0070] Designing the pressure relief valve 13 of the single cell 1 directly with the positive electrode 11 of the single cell 1 can, on the one hand, ensure that the pressure relief valve 13 can respond quickly and accurately when the internal pressure of the single cell 1 increases abnormally. This real-time response capability helps to release the gas accumulated inside the single cell 1 in time and prevent the single cell 1 from being in danger due to excessive pressure. On the other hand, since the positive electrode 11 is one of the main areas where heat is generated inside the single cell 1, designing the pressure relief valve 13 at the positive electrode 11 of the single cell 1 can more effectively utilize the heat dissipation performance of the pressure relief valve 13, help reduce the battery temperature, and improve the thermal stability of the battery. Thirdly, integrating the pressure relief valve 13 with the battery positive electrode 11 can save space inside the battery and make the battery structure more compact, which helps to improve the energy density and power density of the battery and reduce production costs. Fourthly, by designing the pressure relief valve 13 with the battery positive electrode 11, the manufacturing process of the battery can be simplified and the production difficulty can be reduced. Therefore, the pressure relief valve 13 of the single cell 1 is directly designed together with the positive electrode 11 of the single cell 1, which can not only improve the safety performance and stability of the battery, but also achieve the goals of compact battery structure and simplified manufacturing process.

[0071] See also Figure 1 and Figure 2The busbar of the utility model comprises at least two conductive sheets 2, each conductive sheet 2 comprises a positive electrode welding portion 21 and a negative electrode welding portion 22, a first weak portion 230 is provided at the connection between the positive electrode welding portions 21 of two adjacent conductive sheets 2, and a second weak portion 240 is provided at the connection between the positive electrode welding portion 21 and the negative electrode welding portion 22 of each conductive sheet 2. See 7 and Figure 8 As shown, in each conductive sheet 2, its positive electrode welding portion 21 is connected to the positive electrode 11 of a single battery 1, and its negative electrode welding portion 22 is connected to the negative electrode 12 of another adjacent single battery 1, so as to realize the series connection of the two adjacent single batteries 1; the positive electrode welding portions 21 of the two adjacent conductive sheets 2 are respectively connected to the positive electrodes 11 of the two adjacent single batteries 1, so as to realize the parallel connection of the two adjacent single batteries 1. That is, each conductive sheet 2 realizes the series connection of two adjacent single batteries 1 and forms a battery unit, and the two adjacent battery units are connected through the positive electrode welding portions 21 of the two adjacent conductive sheets 2 to realize the parallel connection of the two adjacent battery units; the two adjacent battery units are staggered, so that the arrangement of the single batteries 1 is more compact, so that more single batteries 1 can be arranged in a unit volume, so as to form a battery module or battery pack with a small volume and large capacitance. Specifically, the connection between the positive electrode welding portion 21 and the positive electrode 11, and the connection between the negative electrode welding portion 22 and the negative electrode 12 can be laser welding, or crimping or screw connection.

[0072] When the positive electrode 11 of the single cell 1 and the pressure relief valve 13 are designed together, and when the busbar and the positive electrode 11 of the single cell 1 are welded together, the busbar will hinder the opening of the pressure relief valve 13. The existing design is to set an avoidance gap on the busbar to avoid the position of the pressure relief valve, but in this way, the area left for the pressure relief valve on the end face of the battery is very limited, resulting in a smaller opening of the pressure relief valve, and the pressure relief is not fast enough. In addition, the setting of the avoidance gap will also reduce the connection area between the busbar and the positive electrode, thereby weakening the connection strength. For this reason, when designing the positive electrode 11 and the pressure relief valve 13 of the single cell 1 together, the present application sets the first weak portion 230 and the second weak portion 240 opposite to the thinning area 131, see Figure 7 and Figure 8 , so that when the pressure relief valve 13 releases pressure, the pressure relief valve 13 can break through the first weak portion 230 and the second weak portion 240, thereby ensuring that the pressure relief valve 13 can release pressure efficiently without being affected by the obstruction of the bus bar.

[0073] In this embodiment, the first weak portion 230 and the second weak portion 240 of the busbar are arranged opposite to the thinned area 131. When the pressure relief valve 13 releases pressure, the thinned area 131 will be first opened by the high-pressure gas in the single battery 1, and the impact force of the rapid opening of the pressure relief valve 13 will break the first weak portion 230 and the second weak portion 240 (see Figure 4 , Figure 5 , Fig. 9 and Fig.10 As shown), the pressure relief valve 13 can release pressure efficiently without being affected by the obstruction of the busbar; in addition, see Fig. 9 and Fig.10 As shown, when the first weak part 230 and the second weak part 240 are disconnected, the circuit connection loop between the two adjacent single cells 1 will also be disconnected, so that even if a short circuit occurs on the single cell 1, short circuit protection can be carried out in time, and finally the dual protection of internal pressure relief protection and battery short circuit protection when the single cell 1 is abnormal is achieved simultaneously, providing enhanced protection for the thermal safety and electrical safety operation of the battery. In addition, the first weak part 230 and the second weak part 240 will also be melted due to overcurrent when subjected to strong current, which can also achieve the purpose of dual protection, realizing internal pressure relief protection when the single cell 1 is abnormal and battery short circuit protection between single cells 1.

[0074] Regarding the situation where the first weak portion 230 and the second weak portion 240 will melt due to overcurrent when subjected to a strong current, there are two specific melting conditions. The first melting condition is that since the first weak portion 230 realizes the parallel connection of two single cells 1, when a circuit short circuit or thermal runaway occurs inside the single cell 1, or a circuit short circuit or collision occurs outside the single cell 1, the first weak portion 230 will melt and then be able to cut off the short circuit from spreading to the parallel single cells 1, thereby preventing the thermal runaway from spreading to the adjacent single cells 1; the second melting condition is that since the second weak portion 240 realizes the series connection of two single cells 1, when the battery module composed of the single cells 1 has an external short circuit or is short-circuited within the battery module due to a collision, etc., the second weak portion 240 will melt and then be able to cut off the short circuit from spreading to the series-connected single cells 1, thereby preventing the thermal runaway from spreading to the adjacent single cells 1.

[0075] When an abnormality occurs in the battery, such as an external collision, a circuit short circuit and thermal runaway of the battery will generally occur simultaneously. Therefore, the dual protection of internal pressure relief protection and cell short circuit protection implemented simultaneously in the present application can effectively enhance the safe operation of the battery. In addition, the present application uses the pressure relief valve 13 with the first weak part 230 and the second weak part 240 opened to break, so as to achieve circuit short circuit protection. Compared with the short circuit protection achieved by fusing, it is faster, takes less time, and is therefore safer.

[0076] In this embodiment, see Fig. 9 and Fig.10As shown, since the positive electrode 11 and the pressure relief valve 13 of the single battery 1 are an integrated structure, and the pressure relief valve 13 is arranged around the positive electrode 11, the thinned area 131 of the pressure relief valve 13 is close to the negative electrode 12. After the pressure relief valve 13 is opened for pressure relief, the first weak portion 230 and the second weak portion 240 are broken, which will cause the pressure relief valve 13 and the positive electrode 11 to fall off from the single battery 1 together, and the opening of the pressure relief valve 13 can be further enlarged, so as to achieve rapid and timely pressure relief of the single battery 1.

[0077] In some embodiments, if the pressure relief valve 13 is not opened normally or does not need to be opened, or the pressure after the pressure relief valve 13 is opened is relatively small, that is, the first weak portion 230 and the second weak portion 240 are not broken, when a short circuit occurs in the battery circuit, the first weak portion 230 and the second weak portion 240 can also be melted by the overloaded large current, thereby providing short-circuit protection between the single cells 1 and preventing the spread of thermal runaway.

[0078] In this embodiment, see Figure 1 and Figure 2 As shown, there are two first weak parts 230, and the two first weak parts 230 are respectively close to the positive electrode welding parts 21 of the two adjacent conductive sheets 2, and the two first weak parts 230 are respectively opposite to the thinning areas 131 of the two adjacent pressure relief valves 13. The present application adopts two first weak parts 230, and the two first weak parts 230 are respectively opposite to the thinning areas 131 of the two adjacent pressure relief valves 13. When any one of the pressure relief valves 13 is opened for pressure relief, the connection between the two adjacent conductive sheets 2 can be independently broken, ensuring that the pressure relief valve 13 on each single battery 1 can be smoothly opened to achieve efficient pressure relief, and short circuit protection on any single battery 1 can also be achieved; the two first weak parts 230 are set, when any one of the adjacent pressure relief valves 13 is opened for pressure relief, the first weak part 230 and the second weak part 240 on the corresponding conductive sheet 2 can be broken, so that the connection between the two adjacent conductive sheets 2 can be independently broken, so that each conductive sheet 2 can fall off with the corresponding pressure relief valve 13 and the positive electrode 11 falling off from the end of the single battery 1. In some embodiments, the first weak portion 230 can also be set to one, as long as the first weak portion 230 corresponding to the thinned area 131 of the pressure relief valve 13 is easily broken by the opened pressure relief valve 13. However, setting the first weak portion 230 to one may cause the connection strength of the positive electrode welding portion 21 of the two adjacent conductive sheets 2 to become weaker. When the battery is subjected to external impact, the first weak portion 230 will be severely deformed or even broken.

[0079] Furthermore, in order to enhance the connection strength of the positive electrode welding portions 21 of two adjacent conductive sheets 2, the positive electrode welding portions 21 of two adjacent conductive sheets 2 are connected by a first connecting strip 23, and two first weak portions 230 are located on the first connecting strip 23 and are respectively provided at both ends of the first connecting strip 23. The first connecting strip 23 can not only ensure the connection strength between the two adjacent conductive sheets 2, and facilitate the transportation and installation of the busbar, but also withstand external impact force to avoid the first weak portion 230 from breaking. In addition, the first connecting strip 23 can also carry large current to reduce electrical loss.

[0080] In this embodiment, see Figure 1 and Figure 2 As shown, the first weak portion 230 is a first connecting piece with a first notch 2301, and the first connecting piece is located at both ends of the first connecting piece strip 23. Preferably, the first notch 2301 is located in the middle of the first connecting piece, and in this case, the first notch 2301 is a through hole. The first connecting piece forms a first breakable portion 2302 on both sides of the first notch 2301, and the sum of the cross-sectional areas of the two first breakable portions 2302 is not greater than the cross-sectional area of ​​the first notch 2301.

[0081] The first notch 2301 of the present application is set to reduce the cross-section of the first connecting piece, so that when the pressure relief valve 13 is opened, the first weak portion 230 can be easily and quickly cut off. When the first notch 2301 is located in the middle of the first connecting piece, the first notch 2301 is a through hole, and the first connecting piece forms a first easily breakable portion 2302 on both sides of the first notch 2301, and the cross-section of the first easily breakable portion 2302 is much smaller than the cross-sectional area of ​​the first notch 2301. Under the condition that the first easily breakable portion 2302 can withstand the rated current of the single battery 1 during charging and discharging, the width and thickness of the first easily breakable portion 2302 can be designed to be as small as possible, so that the first weak portion 230 is more easily cut off by the opened pressure relief valve 13.

[0082] Furthermore, in order to ensure that the first easily breakable portion 2302 can withstand the rated current of the single cell 1 during charging and discharging, and that the first weak portion 230 is more easily broken by the impact force of the opened pressure relief valve 13, it is also necessary to ensure the connection strength of the first weak portion 230 during installation and transportation. To this end, the present application sets the width value of the first easily breakable portion 2302 to a, sets the width value of the first connecting piece to b, and sets the ratio range of a / b to 0.12-0.15. The preferred values ​​are 0.13 and 0.14. When the ratio of a / b is less than 0.12, the first weak portion 230 may sometimes be fused due to being unable to withstand the rated current during charging and discharging of the battery, and may sometimes fail to meet the connection strength requirements, making it easy to deform or break during installation and transportation. When the ratio of a / b is greater than 0.15, although the first weak portion 230 can meet the rated current requirements during battery charging and discharging, as well as the connection strength requirements, the first weak portion 230 will not be easily broken by the impact force of the opened pressure relief valve 13, or will not be easily melted in an overcurrent state, thereby causing the double protection of the first weak portion 230 to fail. For this reason, the ratio range of a / b needs to be set to within 0.12-0.15.

[0083] In this embodiment, the width value of the first breakable portion 2302 is 0.7mm, and its error floating value is plus or minus 0.05mm, that is, the width value of the first breakable portion 2302 is between 0.65mm-0.75mm; correspondingly, the width value of the first connecting piece is 5mm, and its error floating value is plus or minus 0.05mm, that is, the width value of the first connecting piece is between 4.95mm-5.05mm.

[0084] In this embodiment, see Figure 1 and Figure 2 As shown, in a single conductive sheet 2, its positive electrode welding part 21 and its negative electrode welding part 22 are connected through the second connecting strip 24, and the second weak part 240 is arranged on the second connecting strip 24, and the second weak part 240 is close to the positive electrode welding part 21. The second connecting strip 24 is provided in the present application to enhance the connection strength between the positive electrode welding part 21 and the negative electrode welding part 22 in each conductive sheet 2. When the battery is subjected to its own expansion force or external force impact, the second connecting strip 24 can be deformed accordingly to avoid the second weak part 240 from being broken. The second connecting strip 24 mainly realizes the series connection of two adjacent single batteries 1, and the current to be carried is large, so the width of the second connecting strip 24 is wide and the cross section is large; while the first connecting strip 23 mainly realizes the parallel connection of two adjacent single batteries 1, and the current to be carried is small, so the width of the first connecting strip 23 is narrow and the cross section is small. For this reason, the width value of the second connecting strip 24 is set to be greater than the width value of the first connecting strip 23.

[0085] Furthermore, the second weak portion 240 is a second connecting piece with a second notch 2401, and the second notch 2401 is also for reducing the cross-sectional area of ​​the second connecting piece. The second notch 2401 is located in the middle of the second connecting piece, and the second connecting piece forms a second breakable portion 2402 on both sides of the second notch 2401, and the cross-sectional area of ​​the second breakable portion 2402 is much smaller than the cross-sectional area of ​​the second notch 2401.

[0086] The setting of the second notch 2401 of the present application reduces the cross-section of the second connecting piece, so that the second weak portion 240 can be easily and quickly cut off when the pressure relief valve 13 is opened. When the second notch 2401 is located in the middle of the second connecting piece, the second notch 2401 is a through hole, and the second connecting piece forms a second easily breakable portion 2402 on both sides of the second notch 2401, and the cross-section of the second easily breakable portion 2402 is much smaller than the cross-sectional area of ​​the second notch 2401, so that the second weak portion 240 is more easily cut off by the opened pressure relief valve 13. Under the condition of ensuring that the second easily breakable portion 2402 can withstand the rated current of the single cell 1 during charging and discharging, the width and thickness of the second easily breakable portion 2402 can be designed to be as small as possible, so that the second weak portion 240 is more easily cut off by the opened pressure relief valve 13.

[0087] Furthermore, in order to ensure that the second easily breakable portion 2402 can withstand the rated current of the single cell 1 during charging and discharging, and that the second weak portion 240 is more easily broken by the impact force of the opened pressure relief valve 13, it is also necessary to ensure the connection strength of the second weak portion 240 during installation and transportation. To this end, the present application sets the width value of the second easily breakable portion 2402 to a, the width value of the second connecting piece to b, and the ratio range of a / b to 0.073-0.077. The preferred values ​​are 0.074, 0.075 and 0.076. When the ratio of a / b is less than 0.073, the second weak portion 240 may be fused because it cannot withstand the rated current of the battery during charging and discharging, and may not meet the connection strength requirements, making it easy to deform or break during installation and transportation. When the ratio of a / b is greater than 0.077, although the second weak portion 240 can meet the rated current requirements during battery charging and discharging, as well as the connection strength requirements, the second weak portion 240 will not be easily broken by the impact force of the opened pressure relief valve 13, or will not be easily melted in an overcurrent state, thereby causing the double protection of the second weak portion 240 to fail. For this reason, the ratio range of a / b needs to be set to within 0.073-0.077.

[0088] In this embodiment, the width of the second fragile portion 2402 is 2.1 mm, and its error floating value is plus or minus 0.05 mm, that is, the width of the second fragile portion 2402 is between 2.05 mm and 2.15 mm; correspondingly, the width of the second connecting piece is 28 mm, and its error floating value is plus or minus 0.05 mm, that is, the width of the second connecting piece is

[0089] Between 27.95mm-28.05mm.

[0090] When the busbar connects multiple single cells 1 in series and in parallel to form a battery module, and foam glue needs to be injected between adjacent single cells 1 for foaming so that all single cells 1 are bonded together by the foam glue, the second notch 2401 can be used as a glue leakage hole, and the adjacent single cells 1 are bonded together by the foam glue injected from the glue leakage hole, and the excess glue can also overflow from the glue leakage hole to ensure the uniformity of the glue filling between adjacent single cells 1. In some embodiments, the foam glue can also be other adhesive glue.

[0091] In this embodiment, see Figure 2 and Figure 3 As shown, the second connecting strip 24 is provided with a buffer step 25, the positive electrode welding portion 21 and the second weak portion 240 are both located on the upper step surface 250 of the buffer step 25, and the negative electrode welding portion 22 is located on the lower step surface 251 of the buffer step 25. In the vertical direction, the upper step surface 250 is located above the lower step surface 251. In the single battery 1 with the positive and negative electrodes 12 on the same end surface, there will be a certain height difference between the upper surface of the positive electrode 11 and the upper surface of the negative electrode 12. This height difference is convenient for the busbar to connect the positive electrode column and the negative electrode 12 respectively, and it is not easy to cause a short circuit in the single battery 1. In this embodiment, the upper surface of the positive electrode 11 is higher than the upper surface of the negative electrode 12, so the upper step surface 250 is located above the lower step surface 251. In addition, the upper surface of the positive electrode 11 of the single cell 1 is also higher than the upper surface of the pressure relief valve 13 of the single cell 1, so that there is a gap between the bottom surface of the second weak portion 240 and the upper surface of the corresponding pressure relief valve 13. When it is necessary to inject foam glue between adjacent single cells 1 for foaming, the second notch 2401 serves as a glue leakage hole. After the foam glue is injected from the second notch 2401, with the help of the gap between the bottom surface of the second weak portion 240 and the upper surface of the corresponding pressure relief valve 13, the foam glue can be combed and flow into the gap between the adjacent single cells 1.

[0092] The present application provides a buffer step 25, which can firstly match the height difference between the positive electrode 11 and the negative electrode 12, so that the positive electrode welding portion 21 can fit with the upper surface of the positive electrode 11, and the negative electrode welding portion 22 can fit with the upper surface of the negative electrode 12, which is convenient for welding and fixing the bus and the positive and negative electrodes 12; secondly, it can provide a buffer for the slight relative movement between two adjacent single cells 1, avoiding deformation or breaking of the second weak portion 240.

[0093] Furthermore, the upper step surface 250 is connected to the lower step surface 251 by the inclined surface 252, and the connection between the upper step surface 250, the lower step surface 251 and the inclined surface 252 is arc-shaped. The arc and the inclined surface 252 both provide a greater buffering deformation for the buffer step 25, thereby enabling it to withstand a greater impact force or relative displacement. The height difference between the upper step surface 250 and the lower step surface 251 is 1-2 mm, preferably, the height difference is 1.5 mm.

[0094] Furthermore, a processing positioning hole 26 is provided in the second connecting strip 24, and the processing positioning hole 26 is located between the buffer step 25 and the second weak portion 240. The processing positioning hole 26 provides positioning for the busbar during processing, so as to achieve accurate processing of the busbar.

[0095] In this embodiment, see Figure 6 As shown, the positive electrode 11, the negative electrode 12 and the pressure relief valve 13 of the single battery 1 are coaxially arranged, and the positive electrode 11 is in the middle, and the outside is surrounded by the pressure relief valve 13 and the negative electrode 12 in sequence. That is, the positive electrode 11 is a pole, and the pressure relief valve 13 and the negative electrode 12 are rings surrounding the pole. Figure 1 and Figure 2 In order to match the annular surface of the negative electrode 12 and avoid the pressure relief valve 13, the negative electrode welding part 22 is provided with a concave arc surface 220 that matches the annular surface; in order to match the circular pole of the positive electrode 11, the positive electrode welding part 21 is a circular surface that matches the upper surface of the circular pole.

[0096] The negative electrode welding part 22 of the present application is provided with a concave arc surface 220, which can increase the welding area with the negative electrode 12 and enhance the connection strength, and secondly, avoid the pressure relief valve 13 to prevent the negative electrode welding part 22 from covering the thinning area 131 of the pressure relief valve 13, thereby causing the pressure relief valve 13 to fail to open normally. The circular surface of the positive electrode welding part 21 cooperates with the circular pole of the positive electrode 11 to increase the connection area and enhance the connection strength.

[0097] In this embodiment, see Figure 1 and Figure 2The positive electrode welding part 21 is provided with a positioning through hole 210 for welding and connecting with the positive electrode 11 of the single battery 1. When the robot performs laser welding, the positive electrode 11 can be locked through the positioning through hole 210, so that the positive electrode welding part 21 can be accurately welded to the positive electrode 11. The positive electrode 11 is provided with a groove opposite to the positioning through hole 210 for accommodating the welding liquid, so that the connection between the positive electrode 11 and the positive electrode welding part 21 is more firmly.

[0098] The positioning through hole 210 of the present technical solution is helpful for finding the positive electrode 11 when the positive electrode welding portion 21 and the positive electrode 11 are laser welded, thereby achieving welding accuracy.

[0099] The utility model also provides a battery module, see Figures 7 to 10 As shown, it comprises a plurality of single cells 1 and the busbar mentioned above, and the busbar connects the plurality of single cells 1 in series and / or in parallel via a plurality of conductive sheets 2, thereby forming a battery module.

[0100] The battery module of the present application places the first weak portion 230 and the second weak portion 240 of the busbar correspondingly above the thinning area 131. When the pressure is released, the pressure relief valve 13 can break the first weak portion 230 and the second weak portion 240, so that the pressure relief valve 13 can release the pressure efficiently and disconnect the circuit connection loop between two adjacent single cells 1, so that even if a short circuit occurs between the single cells 1 or inside and outside the battery module, short circuit protection can be carried out in time, and finally the dual protection of the battery module's partial pressure relief protection and the battery cell short circuit protection is realized simultaneously, thereby improving the thermal safety and electrical safety operation performance of the battery module. In addition, the first weak portion 230 and the second weak portion 240 will also be melted due to overcurrent when subjected to strong current, which can also achieve the dual protection of pressure relief protection and short circuit protection.

[0101] Further, see Figure 7 and Figure 8 As shown, the positive electrode welding parts 21 of two adjacent conductive sheets 2 are respectively connected to the positive electrodes 11 of two adjacent single cells 1, so that the two adjacent single cells 1 are connected in parallel; the positive electrode welding parts 21 and the negative electrode welding parts 22 of each conductive sheet 2 are respectively connected to the positive electrodes 11 and the negative electrodes 12 of two adjacent single cells 1, so that the two adjacent single cells 1 are connected in series. That is, each conductive sheet 2 realizes the series connection of two adjacent single cells 1 to form a battery unit, and the two adjacent battery units are connected through the positive electrode welding parts 21 of the two adjacent conductive sheets 2 to realize the parallel connection of the two adjacent battery units. The two adjacent battery units are staggered, so that the arrangement of the single cells 1 is more compact, so that the battery module has the largest capacity and the smallest volume possible.

[0102] When assembling the battery module, it is necessary to inject foam glue between adjacent single cells 1 for foaming, so that when all single cells 1 are bonded together by the foam glue, the second notch 2401 can be used as a glue leakage hole, and the adjacent single cells 1 are bonded together by the foam glue injected from the glue leakage hole, and the excess glue can also overflow from the glue leakage hole to ensure the uniformity of the glue filling between adjacent single cells 1. In some embodiments, the foam glue can also be other adhesive glue.

[0103] This embodiment also provides a battery pack, including the above-mentioned battery module.

[0104] The battery pack of the present application sets the first weak portion 230 and the second weak portion 240 of the bus bar opposite to the thinned area 131. When the pressure relief valve 13 releases pressure, the thinned area 131 will be first opened by the high-pressure gas in the single cell 1, and the impact force of the rapid opening of the pressure relief valve 13 will break the first weak portion 230 and the second weak portion 240, which can ensure that the pressure relief valve 13 can release pressure efficiently while disconnecting the circuit connection loop between two adjacent single cells 1, so that even if a short circuit occurs in the single cell 1 or the battery module or the battery pack, short-circuit protection can be carried out in time, and finally the dual protection of internal pressure relief protection and cell short-circuit protection of the battery pack is realized simultaneously, thereby improving the thermal safety and electrical safety operation performance of the battery pack; in addition, the first weak portion 230 and the second weak portion 240 will also be melted due to overcurrent when subjected to strong current, which can also achieve the dual protection of pressure relief protection and short-circuit protection.

[0105] The battery pack of this embodiment can be applied to a variety of fields, for example, it can be installed on electric equipment such as electric vehicles, electric bicycles, electric motorcycles, and can also be installed on mobile devices such as smart phones, and can also be installed on drones, model aircraft, as well as energy storage systems such as grid energy storage and solar energy storage, and can even be used in industrial robots and medical equipment.

[0106] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A busbar for connecting a plurality of single cells in series and / or in parallel, characterized in that: At least two conductive sheets are included, each conductive sheet includes a positive electrode welding portion and a negative electrode welding portion; A first weak portion is provided at the connection between the positive electrode welding portions of two adjacent conductive sheets, and a second weak portion is provided at the connection between the positive electrode welding portion and the negative electrode welding portion of each conductive sheet; In each of the conductive sheets, the positive electrode welding portion is connected to the positive electrode of the single cell, and the negative electrode welding portion is connected to the negative electrode of an adjacent single cell; In each of the single cells, a pressure relief valve is provided at the positive electrode thereof, and the pressure relief valve is provided with a thinned area for bursting when the pressure is released, and the first weak portion and the second weak portion are respectively located above the thinned area, and the first weak portion and the second weak portion are broken by a strong impact force when the thinned area bursts, and / or the first weak portion and the second weak portion are melted due to overcurrent when subjected to a strong current.

2. The busbar according to claim 1, characterized in that: The positive electrode welding part and the negative electrode welding part of each conductive sheet are respectively connected to the positive electrode and the negative electrode of two adjacent single batteries, so that the two adjacent single batteries are connected in series to form a battery unit; the two adjacent battery units are connected through the positive electrode welding parts of the two conductive sheets thereon to achieve parallel connection of the two adjacent battery units; a first connecting strip is provided at the connection between the positive electrode welding parts of the two conductive sheets on the two adjacent battery units, and the first weak part is provided on the first connecting strip.

3. The busbar according to claim 2, characterized in that: There are two first weak portions, which are respectively arranged at two ends of the first connecting strip and close to the corresponding positive electrode welding portion, and the two first weak portions are respectively opposite to the thinning areas of two adjacent pressure relief valves.

4. The busbar according to any one of claims 1 to 3, characterized in that: The first weak portion is a connecting piece with a first notch.

5. The busbar according to claim 4, characterized in that: The first notch is located in the middle of the connecting piece.

6. The busbar according to claim 4, characterized in that: The connecting piece forms breakable portions on both sides of the first notch, and the sum of the cross-sectional areas of the two breakable portions is not greater than the cross-sectional area of ​​the first notch.

7. The busbar according to claim 6, characterized in that: The width of the breakable portion is a, the width of the connecting piece is b, and the ratio of a / b is in the range of 0.12-0.

15.

8. The busbar according to claim 1, characterized in that: In a single conductive sheet, the positive electrode welding portion and the negative electrode welding portion are connected via a second connecting strip, the second weak portion is disposed on the second connecting strip, and the second weak portion is close to the positive electrode welding portion.

9. The busbar according to claim 1 or 8, characterized in that: The second weak portion is a connecting piece with a second notch.

10. The busbar according to claim 9, characterized in that: The second notch is located in the middle of the connecting piece, and the connecting piece forms breakable portions on both sides of the second notch, and the cross-sectional area of ​​the breakable portions is much smaller than the cross-sectional area of ​​the second notch.

11. The busbar according to claim 10, characterized in that: The width of the breakable portion is a, the width of the connecting piece is b, and the ratio of a / b is in the range of 0.073-0.

077.

12. The busbar according to claim 8, characterized in that: The second connecting strip is provided with a buffer step, the positive electrode welding portion and the second weak portion are both located on the upper step surface of the buffer step, the negative electrode welding portion is located on the lower step surface of the buffer step, and the upper step surface is connected to the lower step surface via an inclined surface.

13. The busbar according to claim 12, characterized in that: The height difference between the upper step surface and the lower step surface is 1-2 mm.

14. The busbar according to claim 1 or 8, characterized in that: The negative electrode of the single battery is an annular surface, and the negative electrode welding part is provided with an inwardly concave arc surface matching with the annular surface; the positive electrode of the single battery is a circular pole, and the positive electrode welding part is a circular surface matching with the circular pole.

15. The busbar according to any one of claims 1 to 3, characterized in that: The positive electrode welding portion is provided with a positioning through hole for welding connection with the positive electrode of the single battery.

16. The busbar according to claim 1, characterized in that: The pressure relief valve is arranged around the positive electrode. When the pressure is released, the positive electrode falls off along with the pressure relief valve.

17. The busbar according to claim 1 or 16, characterized in that: The negative electrode of the single cell is arranged around the pressure relief valve, and the thinned area is arranged close to the negative electrode.

18. A battery module, characterized in that: It comprises a plurality of single cells and a busbar as claimed in any one of claims 1 to 17, wherein the busbar connects the plurality of single cells in series and / or in parallel via the conductive sheet.

19. The battery module according to claim 18, characterized in that: The positive electrode welding part and the negative electrode welding part of the conductive sheet are respectively connected to the positive electrode and the negative electrode of two adjacent single batteries, so that the two adjacent single batteries are connected in series to form a battery unit; the two adjacent battery units are connected through the positive electrode welding parts of the two adjacent conductive sheets to achieve parallel connection of the two adjacent battery units.

20. The battery module according to claim 18, characterized in that: The second notch is a glue leakage hole, and two adjacent single batteries are bonded together by the sticky glue injected from the glue leakage hole.

21. A battery pack, characterized in that: Comprising a battery module as described in any one of claims 18-20.

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