Battery pack and energy storage device

Abstract

A battery pack and energy storage device are disclosed, relating to the field of energy storage technology. A collection tank and a first junction tank are connected on the bottom plate of the housing. A battery module is mounted and fixed on the bottom plate. When electrolyte leakage occurs in the battery module, the electrolyte can flow along the outer surface of the battery module to the first junction tank and / or the collection tank under gravity. Since the first junction tank and the collection tank are connected, the electrolyte flowing into the first junction tank can flow into the collection tank. Because there is a certain distance between the first junction tank and the bottom of the battery module, and between the bottom of the collection tank and the bottom of the battery module, the electrolyte accumulated in the first junction tank and / or the collection tank will not directly contact the bottom of the battery module. This prevents direct electrical connection between the battery module and the housing via electrolyte, improving the safety and reliability of the battery pack.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a battery pack and energy storage device. Background Technology

[0002] With the rapid development of electric vehicles, energy storage power stations, and other fields, battery packs are widely used as power supply devices. As the core energy carrier, the safety and reliability of battery packs are crucial considerations. Battery modules within battery packs typically use liquid electrolytes, and in actual use, leakage can occur. Because the electrolyte is conductive, it can create abnormal conductive paths between the battery module and the casing, leading to insulation failure and internal short circuits. In severe cases, this can cause thermal runaway of the battery module, resulting in serious safety incidents. Summary of the Invention

[0003] This application provides a battery pack and energy storage device that collects leaked electrolyte from the battery module through a collection tank and a first manifold. The leaked electrolyte is less likely to come into contact with the battery module, thereby improving the safety and reliability of the battery pack.

[0004] In a first aspect, this application provides a battery pack including a housing and a battery module. The housing forms a receiving cavity for housing the battery module, and the battery module is disposed on a bottom plate of the housing. The bottom plate has a collection groove and a first confluence groove disposed on the outer periphery of the collection groove. The collection groove and the first confluence groove communicate with each other. The openings of both the collection groove and the first confluence groove face the battery module and communicate with the receiving cavity. Along the arrangement direction of the battery module and the bottom plate, the orthographic projection of the collection groove at least partially overlaps with the orthographic projection of the battery module.

[0005] In the battery pack of this application, a collection tank and a first confluence tank are provided on the bottom plate of the casing. The battery module is installed and fixed on the bottom plate. When the battery module leaks electrolyte, the electrolyte can flow along the outer surface of the battery module to the first confluence tank and / or the collection tank under the action of gravity. Since the first confluence tank and the collection tank are connected, the electrolyte flowing into the first confluence tank can flow into the collection tank. Because there is a certain distance between the first confluence tank and the bottom of the battery module, and between the bottom of the collection tank and the bottom of the battery module, the electrolyte accumulated in the first confluence tank and / or the collection tank will not directly contact the bottom of the battery module. This prevents the battery module and the casing from being directly connected by electrolyte, thereby improving the safety and reliability of the battery pack.

[0006] The first manifold serves two purposes. First, it increases the effective capacity of the electrolyte storage within the casing. Without needing to drain the electrolyte, the first manifold and the collection tank can completely collect any electrolyte that may leak from the battery module. Second, the first manifold is located on the outer periphery of the collection tank, closer to the side wall of the battery module. This ensures that the battery module is stably mounted on the base plate, allowing electrolyte leaking from the side wall of the battery module to first collect in the first manifold. This prevents the electrolyte leaking from the side wall of the battery module from contacting the side plate of the casing, thereby reducing or eliminating the phenomenon of direct conduction between the side wall of the battery module and the side wall of the casing through the electrolyte.

[0007] Furthermore, the first manifold and the collection tank are directly recessed into the base plate, simplifying the machining process and reducing manufacturing costs. The openings of both the collection tank and the first manifold face the battery module, allowing electrolyte leaking from the bottom of the battery module to fall directly into the collection tank under gravity. This design also maximizes the size of the inlets for electrolyte into the collection tank and the first manifold, minimizing or preventing leaked electrolyte from flowing into other parts of the casing.

[0008] In one possible implementation, the orthographic projection of the sidewall of the battery module falls within the first busbar along the arrangement direction of the battery module and the base plate, or the sidewall of the battery module is flush with the sidewall of the first busbar, and both the sidewall of the first busbar and the sidewall of the battery module extend along the arrangement direction of the battery module and the base plate.

[0009] In other words, the sidewall of the battery module is located above the opening of the first busbar. Electrolyte leaking from the sidewall of the battery module can fall directly into the first busbar under gravity, accumulate in the first busbar, or flow from the first busbar to the collection tank, reducing or avoiding the situation where the electrolytic cell is conductively connected to the housing and the battery module.

[0010] When the sidewall of the battery module is flush with the sidewall of the first busbar, the sidewall of the battery module can be flush with the sidewall of the first busbar near the collection tank. At this time, the opening of the first busbar is outside the sidewall of the battery module. The electrolyte leaking from the sidewall of the battery module can directly enter the first busbar through the opening of the first busbar under the action of gravity. The electrolyte leaking from the bottom of the battery module can also flow into the first busbar more quickly along the sidewall of the first busbar.

[0011] In one possible implementation, along the arrangement direction of the battery module and the base plate, the depth of the first busbar is less than or equal to the depth of the collection tank.

[0012] When the depth of the first busbar is less than the depth of the collection tank, the bottom of the first busbar is closer to the bottom of the battery module than the bottom of the collection tank. There is a height difference between the bottom of the first busbar and the bottom of the collection tank. The electrolyte flowing into the first busbar can flow more smoothly into the collection tank under the action of gravity. The collection tank is deeper, so the electrolyte collected in the collection tank will not directly contact the bottom of the battery module, thereby preventing the battery module and the casing from being directly connected through the electrolyte, thus improving the safety and reliability of the battery pack.

[0013] When the depth of the first manifold is equal to the depth of the collection tank, the first manifold can collect the electrolyte leaking from the side wall of the battery module, and the collection tank can directly collect the electrolyte leaking from the bottom of the battery module. The collection tank and the first manifold have the same depth and are interconnected. After the electrolyte accumulates in the first manifold near the connection point with the collection tank, it can also flow into the collection tank from the connection point. The first manifold can not only serve to collect the electrolyte, but also to increase the space for collecting electrolyte in the box. Even if the electrolyte cannot be separated or discharged in time, the insulation between the box and the battery module can still be maintained, ensuring the safety and reliability of the battery pack.

[0014] In one possible implementation, the first confluence channel is an annular channel, which surrounds the outer periphery of the collection channel.

[0015] The annular first manifold allows electrolyte leakage from any location on the side wall of the battery module to flow into the first manifold along the direction of gravity and then collect in the collection tank connected to the first manifold.

[0016] In one possible implementation, the base plate is further provided with a second busbar, which is located between the collection tank and the first busbar and connects the first busbar and the collection tank. The opening of the second busbar faces the battery module.

[0017] A second concave manifold is formed on the base plate, facing away from the battery module, to connect the first manifold and the collection tank. This allows the electrolyte in the first manifold to be collected into the collection tank through the second manifold. Furthermore, the opening of the second manifold faces the battery module, increasing the inlet area for electrolyte leaking from the battery module to flow into the collection tank. This increases the path for leaking electrolyte to enter the collection tank; that is, electrolyte leaking from the bottom of the battery module directly opposite the second manifold can fall directly into the second manifold and then flow into the collection tank.

[0018] In one possible implementation, the depth of the second manifold is less than or equal to the depth of the collection trough along the arrangement direction of the battery module and the base plate.

[0019] When the depth of the second busbar is less than the depth of the collection tank, the bottom of the second busbar is closer to the battery module than the bottom of the collection tank. This creates a height difference between the bottoms of the two busbars, allowing the electrolyte flowing into the second busbar to flow more smoothly into the collection tank under gravity. Meanwhile, the greater depth of the collection tank prevents the electrolyte from directly contacting the bottom of the battery module, thus preventing direct conductivity between the battery module and the housing through the electrolyte and improving the safety and reliability of the battery pack.

[0020] When the depth of the second manifold is equal to the depth of the collection tank, the second manifold can collect electrolyte leaking from the bottom of the battery module and / or electrolyte flowing into the second manifold from the first manifold. The collection tank can also directly collect electrolyte leaking from the bottom of the battery module. Since the collection tank and the second manifold have the same depth and are connected, electrolyte in the second manifold can also flow into the collection tank. The second manifold not only serves to collect electrolyte but also increases the space for collecting electrolyte inside the box. Even if the electrolyte cannot be separated or drained in time, the insulation between the box and the battery module can still be maintained, ensuring the safety and reliability of the battery pack.

[0021] In one possible implementation, the depth of the second manifold is greater than or equal to the depth of the first manifold along the arrangement direction of the battery module and the base plate.

[0022] When the depth of the second busbar is greater than that of the first busbar, the bottom of the second busbar is further away from the battery module than the bottom of the first busbar, resulting in a height difference between the bottom of the second busbar and the bottom of the first busbar. The electrolyte in the first busbar can flow smoothly into the second busbar and then be collected in the collection tank through the second busbar.

[0023] When the depth of the second busbar is equal to the depth of the first busbar, on the one hand, it ensures that the base plate has sufficient thickness to support the battery module. On the other hand, the second busbar and the first busbar can also serve to combine and collect electrolyte, thereby increasing the space for collecting electrolyte in the box. Even if the electrolyte cannot be separated or discharged in time, the insulation between the box and the battery module can still be maintained, ensuring the safety and reliability of the battery pack.

[0024] In one possible implementation, along the arrangement direction of the battery module and the base plate, there is a gap between the side of the battery module facing the base plate and the surface of the base plate closest to the battery module.

[0025] In other words, there is a gap between the bottom of the battery module and the surface of the base plate closest to the battery module, separating the bottom of the battery module from the surface of the base plate closest to the battery module. In this way, the electrolyte leaking out of or flowing to the bottom of the battery module is not obstructed by the bottom of the battery module and the surface of the base plate closest to the battery module, and the electrolyte can flow smoothly into the collection tank and the first confluence tank.

[0026] In one possible implementation, the battery cell of the battery module includes a body, a positive terminal and a negative terminal, with an electrolyte inside the body, a positive terminal and a negative terminal on the top of the body, and the bottom of the body mounted on a base plate.

[0027] By placing the battery cell upright on the base plate, the electrolyte accumulates at the bottom of the cell during long-term use, away from the positive and negative electrode welding area. This reduces or avoids the possibility of electrolyte seeping into the welding area, thereby lowering the risk of cell leakage.

[0028] Secondly, this application provides an energy storage device comprising a plurality of battery packs as provided in any implementation of the first aspect, wherein the plurality of battery packs are stacked.

[0029] In one possible implementation, the energy storage device further includes a power converter for converting direct current (DC) from the energy storage device into alternating current (AC) and supplying it to the power grid or load. And / or, the power converter is used to convert AC from an external AC power source into DC and supply it to the energy storage device. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0031] Figure 1 This application provides a schematic diagram of the architecture of an energy storage system according to one embodiment. Figure 2 A three-dimensional structural schematic diagram of a battery pack provided in an embodiment of this application; Figure 3 for Figure 2 The diagram shows the exploded structure of the battery pack. Figure 4 This is a cross-sectional structural diagram of a battery pack provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a box provided in one embodiment of this application; Figure 6 A cross-sectional structural schematic diagram of another battery pack provided in an embodiment of this application; Figure 7 This is a three-dimensional structural diagram of a battery module provided in one embodiment of this application; Figure 8 This is an exploded view of a battery pack according to an embodiment of this application.

[0032] Explanation of reference numerals in the attached figures: X - Length direction of battery pack; Y - Width direction of battery pack; Z - Height direction of battery pack; 10 - Housing; 11 - Receiving cavity; 12 - Bottom plate; 121 - Collection slot; 122 - First busbar; 123 - Second busbar; 13 - Top plate; 14 - Side plate; 15 - Cover plate; 16 - Gap; 20 - Battery module; 21 - Cell; 211 - Body; 212 - Positive terminal; 213 - Negative terminal; 22 - End plate; 23 - Fastener; 30 - Insulating strip; 40 - Busbar; 50 - Sampling circuit board; 60 - Power module; 61 - Power board; 62 - Power device; 100 - Battery pack; 1000 - Energy storage device; 2000 - Power converter; 3000 - Power grid; 4000 - Load; 5000 - Photovoltaic array. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0034] The terms "first," "second," "third," "fourth," etc., used in this application and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] In this specification, the terms "vertical" and "parallel" are explained.

[0036] Perpendicularity: The perpendicularity defined in this application is not limited to an absolute perpendicular intersection (with an included angle of 90°). It is permissible for non-absolute perpendicular intersections caused by factors such as assembly tolerances, design tolerances, and structural flatness. It is permissible for errors within a small angular range, such as an assembly error range of 80° to 100°, which can all be understood as a perpendicular relationship.

[0037] Parallelism: The parallelism defined in this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, allowing for situations where the parallelism is not absolute due to factors such as assembly tolerances, design tolerances, and structural flatness.

[0038] The battery pack 100 provided in this application is used in an energy storage device 1000. The battery pack 100 is used to provide energy storage for the energy storage device 1000 or to supply power to the functional devices in the energy storage device 1000. The energy storage device 1000 can be a photovoltaic energy storage device 1000 or a vehicle-mounted energy storage device 1000, etc.

[0039] Figure 1 This is a schematic diagram of the architecture of an energy storage system according to an embodiment of this application. Figure 1 As shown, the energy storage system includes an energy storage device 1000, a power converter 2000, and a power grid 3000 or a load 4000. The power converter 2000 converts direct current (DC) from the energy storage device 1000 into alternating current (AC) and supplies it to the power grid 3000 or the load 4000. And / or, the power converter 2000 converts AC from an external AC power source into DC and supplies it to the energy storage device 1000. The power converter 2000 may integrate a DC / DC conversion circuit and a DC / AC conversion circuit. The DC / DC conversion circuit converts high-voltage DC to low-voltage DC, and the DC / AC conversion circuit converts the DC power transmitted from the energy storage device 1000 into AC. The energy storage device 1000 includes a base and one or more battery packs 100, which are stacked on the base and connected in series and parallel.

[0040] The energy storage device 1000 can also receive DC power from an external DC power source, such as DC power generated by the photovoltaic array 5000. The electrical energy generated by the photovoltaic array 5000 can be used to charge the energy storage device 1000 after being boosted or bucked by the DC / DC converter circuit. When the electrical energy generated by the photovoltaic array 5000 is insufficient to supply power to the grid 3000 or the load 4000, the electrical energy stored in the energy storage device 1000 can be transferred to the grid 3000 or the load 4000 through the DC / AC converter circuit in the power converter 2000.

[0041] On the other hand, the energy storage device 1000 can also receive power from an external AC power source (such as the power grid). The AC power output from the power grid is converted into DC power by a DC / AC conversion circuit and transmitted to the energy storage device 1000 to charge it. Alternatively, the power converter 2000 may only include a DC / AC conversion circuit, while the energy storage device 1000 may have a built-in DC / DC conversion circuit, allowing it to directly receive DC power generated by the photovoltaic array 5000.

[0042] Please see Figure 2 and Figure 3 , Figure 2 This is a three-dimensional structural diagram of a battery pack 100 provided in an embodiment of this application. Figure 3 for Figure 2 The diagram shows an exploded view of the battery pack 100. This application provides a battery pack 100, which includes a housing 10 and a battery module 20. The housing 10 has a receiving cavity 11 for housing the battery module 20. The housing 10 includes a bottom plate 12, a top plate 13, multiple side plates 14, and a cover plate 15. The bottom plate 12 and top plate 13 are disposed opposite to each other. The multiple side plates 14 are connected to the edges of the bottom plate 12 and top plate 13. The bottom plate 12, top plate 13, and multiple side plates 14 form a space with an opening. The cover plate 15 is detachably fitted onto the opening. The cover plate 15 is disposed opposite to one of the side plates 14. The cover plate 15 is used to seal and shield the space enclosed by the bottom plate 12, top plate 13, and multiple side plates 14 to form the receiving cavity 11 for housing the battery module 20. For example, the housing 10 has a cuboid structure, with three side panels 14. Two side panels 14 are arranged opposite each other along the length of the base plate 12, and the other side panel 14 is arranged opposite to the cover plate 15 along the width of the base plate 12. The base plate 12, top plate 13, and side panels 14 can be integrally formed or separate structures. The base plate 12, top plate 13, and side panels 14 are connected and fixed by means of snap-fit, welding, or screws.

[0043] The battery module 20 is mounted on the base plate 12 of the housing 10. For example, the battery module 20 can be placed on the base plate 12 by means of screws or other means, so that the base plate 12 provides support for the battery module 20.

[0044] The base plate 12 is provided with a collection tank 121 and a first confluence tank 122. The collection tank 121 and the first confluence tank 122 are connected. The openings of both the collection tank 121 and the first confluence tank 122 face the battery module 20 and are connected to the receiving cavity 11. The first confluence tank 122 is disposed on the outer periphery of the collection tank 121. The first confluence tank 122 and the collection tank 121 are used to collect electrolyte leaked from the battery module 20. Along the arrangement direction of the battery module 20 and the base plate 12, the orthographic projection of the collection tank 121 at least partially overlaps with the orthographic projection of the battery module 20. The arrangement direction of the battery module 20 and the base plate 12 can be the height direction Z of the battery pack 100.

[0045] For example, the surface of the base plate 12 facing the battery module 20 is recessed to form a collection groove 121 and a first confluence groove 122. For example, the surface of the base plate 12 facing the battery module 20 is recessed to form a collection groove 121 and a first confluence groove 122 on the side away from the battery module 20. Along the arrangement direction of the battery module 20 and the base plate 12, the depth of the collection groove 121 and the depth of the first confluence groove 122 are both less than the thickness of the base plate 12.

[0046] Battery module 20 is at risk of leakage during use. Whether it is electrolyte leakage or external liquid entering the casing 10, the liquid will pose a safety hazard to battery module 20. Because electrolyte is conductive, it will form an abnormal conductive path between battery module 20 and casing 10, causing insulation failure and internal short circuit. In severe cases, it may lead to thermal runaway of battery module 20 and cause a serious safety accident.

[0047] In the battery pack 100 of this application, a collection tank 121 and a first confluence tank 122 are provided on the bottom plate 12 of the housing 10. The battery module 20 is installed and fixed on the bottom plate 12. When the battery module 20 leaks electrolyte, the electrolyte can flow along the outer surface of the battery module 20 to the first confluence tank 122 and / or the collection tank 121 under the action of gravity. Since the first confluence tank 122 is connected to the collection tank 121, the electrolyte flowing into the first confluence tank 122 can flow into the collection tank 121. Since there is a certain distance between the first confluence tank 122 and the bottom of the battery module 20, and between the bottom of the collection tank 121 and the bottom of the battery module 20, the electrolyte accumulated in the first confluence tank 122 and / or the collection tank 121 will not directly contact the bottom of the battery module 20. This prevents the battery module 20 from being directly connected to the housing 10 through the electrolyte, thereby improving the safety and reliability of the battery pack 100.

[0048] The first manifold 122 serves two purposes. First, it increases the effective capacity of the electrolyte storage within the housing 10. Without needing to drain the electrolyte, the first manifold 122 and the collection tank 121 can completely collect any electrolyte that may leak from the battery module 20. Second, the first manifold 122 is located on the outer periphery of the collection tank 121, closer to the side wall of the battery module 20. This ensures that the battery module 20 is stably mounted on the base plate 12, allowing electrolyte leaking from the side wall of the battery module 20 to first collect in the first manifold 122. This prevents the electrolyte leaking from the side wall of the battery module 20 from contacting the side plate 14 of the housing 10, thereby reducing or eliminating direct electrical connection between the side wall of the battery module 20 and the side wall of the housing 10 via electrolyte. The side wall of the battery module 20 extends along the height direction Z of the battery pack 100.

[0049] Furthermore, the first conduit 122 and the collection tank 121 are directly recessed into the base plate 12, simplifying the process of forming the collection tank 121 and the first conduit 122 on the base plate 12, which helps to reduce manufacturing costs. The openings of the collection tank 121 and the first conduit 122 both face the battery module 20 side, allowing the electrolyte leaking from the bottom of the battery module 20 to fall directly into the collection tank 121 under gravity. The openings for the electrolyte to enter the collection tank 121 and the first conduit 122 are made as large as possible, reducing or preventing leaked electrolyte from flowing into other parts of the housing 10.

[0050] The battery pack 100 of this application is used in an energy storage device 1000. Multiple battery packs 100 are stacked, for example, multiple battery packs 100 are stacked along the height direction Z of the battery pack 100. In this way, when electrolyte leakage occurs in a certain battery pack 100, the leaked electrolyte can flow into the first manifold 122 and the collection tank 121 under the action of gravity.

[0051] Please see Figure 4 , Figure 4 This is a cross-sectional structural diagram of a battery pack 100 provided in an embodiment of this application. Along the height direction Z of the battery pack 100, there is a gap 16 between the surface of the bottom plate 12 closest to the battery module 20 and the side of the battery module 20 facing the bottom plate 12. The surface of the bottom plate 12 facing the battery module 20 is a plane, on which a first busbar 122 and a collection groove 121 are recessed. The position on this plane where the first busbar 122 and the collection groove 121 are not formed is separated from the bottom of the battery module 20 by a gap 16. For example, an insulating strip 30 is provided inside the housing 10. The insulating strip 30 is disposed between the bottom plate 12 and the battery module 20 to separate the battery module 20 and the bottom plate 12, and to form a gap 16 between the bottom of the battery module 20 and the bottom plate 12. This design separates the bottom of the battery module 20 from the surface of the base plate 12 closest to the battery module 20. Electrolyte leaking from or flowing towards the bottom of the battery module 20 is not obstructed by the bottom of the battery module 20 or the surface of the base plate 12 closest to the battery module 20, allowing the electrolyte to flow smoothly into the collection tank 121 and the first confluence tank 122. The insulating strip 30 is made of insulating material to ensure insulation between the battery module 20 and the housing 10.

[0052] In one embodiment, along the height direction Z of the battery pack 100, the orthographic edge of the collection tank 121 is located within the orthographic edge of the battery module 20. The battery module 20 is in contact with the bottom plate 12 located at the edge of the collection tank 121. At this time, if leakage occurs in the part of the bottom of the battery module 20 directly facing the collection tank 121, it can fall directly into the collection tank 121 under the action of gravity.

[0053] In another embodiment, along the height direction Z of the battery pack 100, a portion of the orthographically projected edge of the collection groove 121 lies outside the orthographically projected edge of the battery module 20. For example, along the width direction Y of the battery pack 100, the size of the collection groove 121 is smaller than the size of the battery module 20; along the length direction X of the battery pack 100, the size of the collection groove 121 is larger than the size of the battery module 20; or, for example, along the width direction Y of the battery pack 100, the size of the collection groove 121 is larger than the size of the battery module 20; along the length direction X of the battery pack 100, the size of the collection groove 121 is smaller than the size of the battery module 20. This increases the area of ​​the collection groove 121 covering the bottom of the battery module 20, allowing electrolyte leaking from the bottom of the battery module 20 to fall directly into the collection groove 121.

[0054] Along the height direction Z of the battery pack 100, the outer contour shape of the orthographic projection of the collection slot 121 can be rectangular, circular, or other shapes, without any specific limitation. The number of collection slots 121 can be one or more, with multiple collection slots 121 spaced apart on the base plate 12. Multiple collection slots 121 correspond to one battery module 20, or each collection slot 121 corresponds to one battery module 20.

[0055] In one embodiment, along the width direction Y of the battery pack 100, the size of the collection tank 121 is smaller than the size of the battery module 20, but larger than half the size of the battery module 20; along the length direction X of the battery pack 100, the size of the collection tank 121 is larger than half the size of the battery module 20. This arrangement maximizes the effective capacity of the collection tank 121, enabling it to effectively store the maximum capacity of electrolyte that the battery module 20 may leak. This prevents the electrolyte accumulated in the collection tank 121 from directly contacting the bottom of the battery module 20, thereby preventing direct communication between the battery module 20 and the housing 10 through the electrolyte and improving the safety and reliability of the battery pack 100.

[0056] The first confluencement channel 122 is disposed on the outer periphery of the collection channel 121. For example, the first confluencement channel 122 is an annular channel, and the first confluencement channel 122 surrounds the outer periphery of the collection channel 121. When there are multiple collection channels 121, the first confluencement channel 122 surrounds the outer periphery of multiple collection channels 121, or each collection channel 121 may have a first confluencement channel 122 surrounding its outer periphery. The annular first confluencement channel 122 ensures that when electrolyte leaks from any location on the side wall of the battery module 20, it can flow into the first confluencement channel 122 along the direction of gravity and then collect in the collection channel 121, which is connected to the first confluencement channel 122.

[0057] like Figure 5 As shown, Figure 5This is a schematic diagram of the structure of a housing 10 provided in one embodiment of this application. In other embodiments, the first manifold 122 and the collection trough 121 are arranged along the width direction Y of the battery pack 100, or the first manifold 122 and the collection trough 121 are arranged along the length direction X of the battery pack 100. The dimension of the battery module 20 along the length direction X of the battery pack 100 is greater than the dimension of the battery module 20 along the width direction Y of the battery pack 100. The first busbar 122 and the collection tank 121 can be arranged along the width direction Y of the battery pack 100. For example, the first busbar 122 is located on opposite sides of the collection tank 121 along the width direction Y of the battery pack 100, so that each of the two opposite side walls of the battery module 20 along the width direction Y of the battery pack 100 corresponds to a first busbar 122. The arrangement of the first busbar 122 and the collection tank 121 makes the dimension of the first busbar 122 along the length direction X of the battery pack 100 larger, such as equal to or greater than the dimension of the battery module 20 along the length direction X of the battery pack 100. This allows the electrolyte leaking from either of these two side walls to fall directly into the first busbar 122 under the action of gravity.

[0058] like Figure 4 As shown, along the height direction Z of the battery pack 100, the orthographic projection of the side wall of the battery module 20 falls within the first manifold 122. That is to say, the side wall of the battery module 20 is located above the opening of the first manifold 122. Electrolyte leaking from the side wall of the battery module 20 can fall directly into the first manifold 122 under the action of gravity, accumulating in the first manifold 122 or flowing from the first manifold 122 to the collection tank 121, reducing or avoiding the situation where the electrolytic cell is electrically connected to the housing 10 and the battery module 20.

[0059] like Figure 6 As shown, Figure 6 This is a cross-sectional structural diagram of another battery pack 100 provided in one embodiment of this application. Alternatively, along the height direction Z of the battery pack 100, the sidewall of the battery module 20 is flush with the sidewall of the first busbar 122, wherein the sidewall of the first busbar 122 extends along the height direction Z of the battery pack 100, specifically, the sidewall of the first busbar 122 is parallel to the height direction Z of the battery pack 100. In this embodiment, the sidewall of the battery module 20 is parallel to the sidewall of the first busbar 122 and is on the same plane. The sidewall of the battery module 20 can be flush with the sidewall of the first manifold 122 near the collection tank 121. At this time, the opening of the first manifold 122 is outside the sidewall of the battery module 20. The electrolyte leaking from the sidewall of the battery module 20 can directly enter the first manifold 122 through the opening of the first manifold 122 under the action of gravity. The electrolyte leaking from the bottom of the battery module 20 can also flow into the first manifold 122 more quickly along the sidewall of the first manifold 122.

[0060] Along the height direction Z of the battery pack 100, the depth of the first manifold 122 is less than or equal to the depth of the collection trough 121. For example, the depth of the first busbar 122 is less than the depth of the collection tank 121. Since both the first busbar 122 and the collection tank 121 are formed by the recess of the bottom plate 12 towards the battery module 20, when the depth of the first busbar 122 is less than the depth of the collection tank 121, the bottom of the first busbar 122 is closer to the bottom of the battery module 20 than the bottom of the collection tank 121. There is a height difference between the bottom of the first busbar 122 and the bottom of the collection tank 121. The electrolyte flowing into the first busbar 122 can flow more smoothly into the collection tank 121 under the action of gravity. The collection tank 121 is deeper, so that the electrolyte collected in the collection tank 121 will not directly contact the bottom of the battery module 20, thereby preventing the battery module 20 from being directly connected to the housing 10 through the electrolyte, and improving the safety and reliability of the battery pack 100. For example, the depth of the first manifold 122 is equal to the depth of the collection tank 121. The first manifold 122 can collect the electrolyte leaking from the side wall of the battery module 20, and the collection tank 121 can directly collect the electrolyte leaking from the bottom of the battery module 20. The collection tank 121 and the first manifold 122 have the same depth and are interconnected. After the electrolyte accumulates in the first manifold 122 near the connection port with the collection tank 121, it can also flow into the collection tank 121 from the connection port. The first manifold 122 can not only serve to collect the electrolyte, but also to collect the electrolyte, thereby increasing the space for collecting electrolyte in the housing 10. Even if the electrolyte cannot be separated or discharged in time, the insulation between the housing 10 and the battery module 20 can still be maintained, ensuring the safety and reliability of the battery pack 100.

[0061] Please return to the reference. Figure 3 and Figure 5 The base plate 12 is also provided with a second confluence channel 123, which is located between the collection channel 121 and the first confluence channel 122, and connects the first confluence channel 122 and the collection channel 121. That is, the collection channel 121 is connected to the first confluence channel 122 through the second confluence channel 123. The opening of the second confluence channel 123 faces the battery module 20. The second confluence channel 123 is formed by a recess in the surface of the base plate 12 facing the battery module 20 towards the side opposite to the battery module 20. The second confluence channel 123 is a channel connecting the first confluence channel 122 and the collection channel 121, and has an opening connecting the collection channel 121 and an opening connecting the first confluence channel 122, such as... Figure 3As shown, when the second manifold 123 is positioned between the collection tank 121 and the first manifold 122 along the width direction Y of the battery pack 100, the second manifold 123 has two openings that are opposite each other along the width direction Y of the battery pack 100. This allows the electrolyte flowing into the first manifold 122 to be collected into the collection tank 121 through the second manifold 123. Furthermore, the opening of the second manifold 123 faces the battery module 20, increasing the inlet area for the electrolyte leaking from the battery module 20 to flow into the collection tank 121. This increases the path for the electrolyte leaking from the battery module 20 to enter the collection tank 121. Specifically, electrolyte leaking from the bottom of the battery module 20, which faces the second manifold 123, can directly fall into the second manifold 123 and then flow into the collection tank 121. Moreover, the second manifold 123 is simple to form, which helps to save manufacturing costs.

[0062] The number of second manifolds 123 can be one or more, and multiple second manifolds 123 are spaced apart on the outer periphery of the collection tank 121 so that the electrolyte in the first manifold 122 can flow into the collection tank 121 along a shorter path.

[0063] For example, along the height direction Z of the battery pack 100, the depth of the second busbar 123 is less than or equal to the depth of the collection tank 121. For instance, the depth of the second busbar 123 is less than the depth of the collection tank 121, meaning the bottom of the second busbar 123 is closer to the battery module 20 than the bottom of the collection tank 121. This creates a height difference between the bottom of the second busbar 123 and the bottom of the collection tank 121, allowing the electrolyte flowing into the second busbar 123 to flow more smoothly into the collection tank 121 under gravity. The deeper collection tank 121 prevents the electrolyte collected therefrom from directly contacting the bottom of the battery module 20, thus preventing direct communication between the battery module 20 and the housing 10 via the electrolyte, improving the safety and reliability of the battery pack 100.

[0064] For example, the depth of the second manifold 123 is equal to the depth of the collection tank 121. The second manifold 123 can collect the electrolyte leaking from the bottom of the battery module 20 and / or the electrolyte flowing into the second manifold 123 from the first manifold 122. The collection tank 121 can also directly collect the electrolyte leaking from the bottom of the battery module 20. The collection tank 121 and the second manifold 123 have the same depth and are connected. The electrolyte in the second manifold 123 can also flow into the collection tank 121. The second manifold 123 can not only serve to collect the electrolyte, but also to collect the electrolyte, thereby increasing the space for collecting electrolyte in the housing 10. Even if the electrolyte cannot be separated or discharged in time, the insulation between the housing 10 and the battery module 20 can still be maintained, ensuring the safety and reliability of the battery pack 100.

[0065] For example, along the height direction Z of the battery pack 100, the depth of the second busbar 123 is greater than or equal to the depth of the first busbar 122. For instance, the depth of the second busbar 123 is greater than the depth of the first busbar 122, that is, the bottom of the second busbar 123 is further away from the battery module 20 than the bottom of the first busbar 122, so that there is a height difference between the bottom of the second busbar 123 and the bottom of the first busbar 122, and the electrolyte in the first busbar 122 can flow smoothly into the second busbar 123, and then be collected in the collection tank 121 through the second busbar 123.

[0066] For example, the depth of the second busbar 123 is equal to the depth of the first busbar 122. On the one hand, this ensures that the base plate 12 has sufficient thickness to support the battery module 20. On the other hand, the second busbar 123 and the first busbar 122 can also serve to combine and collect electrolyte, thereby increasing the space for collecting electrolyte within the housing 10. Even if the electrolyte cannot be separated or drained in time, the insulation between the housing 10 and the battery module 20 can still be maintained, ensuring the safety and reliability of the battery pack 100. In addition, since the second busbar 123 and the first busbar 122 have the same depth and are interconnected, electrolyte accumulated in the first busbar 122 near the connection point with the second busbar 123 can also flow into the second busbar 123 from the connection point, and then flow into the collection tank 121 through the second busbar 123.

[0067] Please see Figure 7 , Figure 7 This is a three-dimensional structural diagram of a battery module 20 according to an embodiment of this application. The battery module 20 includes a plurality of battery cells 21, which are arranged along the length direction X of the battery pack 100. End plates 22 are provided at opposite ends of the plurality of battery cells 21 along the length direction X of the battery pack 100. The plurality of battery cells 21 and the end plates 22 are connected and fixed together by fasteners 23. In other embodiments, the plurality of battery cells 21 may be arranged along the width direction Y of the battery pack 100.

[0068] The battery cell 21 includes a body 211, a positive terminal 212, and a negative terminal 213. The body 211 contains electrolyte. The top of the body 211 has the positive terminal 212 and the negative terminal 213. The bottom of the body 211 is mounted on the base plate 12. This arrangement allows the battery cell 21 of the battery module 20 to be placed upright on the base plate 12. During long-term use, the electrolyte accumulates at the bottom of the battery cell 21, away from the welding area of ​​the positive and negative terminals 213, reducing or avoiding the possibility of electrolyte seeping into the welding area, thereby reducing the risk of leakage of the battery cell 21.

[0069] The battery module 20 also includes busbars 40 and sampling circuit boards 50. Multiple busbars 40 connect multiple battery cells 21 in series. The busbars 40 can be made of aluminum, copper, nickel-plated copper, or copper-aluminum, etc. The sampling circuit board 50 can be a flexible printed circuit (FPC), flexible flat cable (FFC), flexible printed circuit assembly (FPCA), etc. The sampling circuit board 50 can perform temperature and voltage sampling of individual battery cells 21, as well as overcurrent protection functions. Both the sampling circuit board 50 and the multiple busbars 40 are located on top of the battery cells 21. The sampling circuit board 50 can be connected to the battery cells via nickel strips or other devices.

[0070] Please see Figure 8 , Figure 8 This is an exploded view of a battery pack 100 according to an embodiment of this application. For example, the battery pack 100 further includes a power module 60, which is disposed within the receiving cavity 11. The power module 60 is connected to the battery module 20 and is used to perform power conversion on the battery module 20. For example, the power module 60 integrates a DC / DC conversion circuit to boost or buck the electrical energy provided by the battery module 20. The power module 60 includes a power board 61 and power devices 62. The power board 61 is connected to the sampling circuit board 50 for processing by the power devices 62 on the power board 61. Power devices 62 are disposed on the surface of power board 61. Power devices 62 include inductors, capacitors and power chips. Power chips are used to convert power for battery module 20. Power chips can be insulated gate bipolar transistors (IGBT), metal-oxide-semiconductor field-effect transistors (MOSFET) or wide bandgap semiconductor devices (SiC / GaN), etc.

[0071] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery pack, characterized in that, The device includes a housing and a battery module. The housing forms a receiving cavity for accommodating the battery module. The bottom plate of the housing is provided with a collection groove and a first confluence groove disposed on the outer periphery of the collection groove. The collection groove is connected to the first confluence groove. The openings of the collection groove and the first confluence groove both face the battery module and are connected to the receiving cavity. The battery module is disposed on the base plate, and along the arrangement direction of the battery module and the base plate, the orthographic projection of the collection groove at least partially overlaps with the orthographic projection of the battery module.

2. The battery pack according to claim 1, characterized in that, Along the arrangement direction of the battery module and the base plate, the orthographic projection of the side wall of the battery module falls within the first manifold, or the side wall of the battery module is flush with the side wall of the first manifold, and the side wall of the battery module extends along the arrangement direction of the battery module and the base plate.

3. The battery pack according to claim 1 or 2, characterized in that, Along the arrangement direction of the battery module and the base plate, the depth of the first confluence channel is less than or equal to the depth of the collection channel.

4. The battery pack according to any one of claims 1-3, characterized in that, The first confluence channel is an annular channel, and the first confluence channel is arranged around the outer periphery of the collection channel.

5. The battery pack according to any one of claims 1-4, characterized in that, The base plate is also provided with a second confluence channel, which is located between the collection channel and the first confluence channel and connects the first confluence channel and the collection channel. The opening of the second confluence channel faces the battery module.

6. The battery pack according to claim 5, characterized in that, Along the arrangement direction of the battery module and the base plate, the depth of the second manifold is less than or equal to the depth of the collection trough.

7. The battery pack according to claim 5 or 6, characterized in that, Along the arrangement direction of the battery module and the base plate, the depth of the second manifold is greater than or equal to the depth of the first manifold.

8. The battery pack according to any one of claims 1-7, characterized in that, Along the arrangement direction of the battery module and the base plate, there is a gap between the side of the battery module facing the base plate and the surface of the base plate closest to the battery module.

9. The battery pack according to any one of claims 1-8, characterized in that, The battery cell of the battery module includes a body, a positive terminal and a negative terminal. The body contains an electrolyte, the positive terminal and the negative terminal are located on the top of the body, and the bottom of the body is mounted on the base plate.

10. An energy storage device, characterized in that, It includes multiple battery packs as described in any one of claims 1-9, wherein the multiple battery packs are stacked.

11. The energy storage device according to claim 10, characterized in that, The energy storage device further includes a power converter for converting direct current from the energy storage device into alternating current and supplying it to the power grid or load; and / or, the power converter for converting alternating current from an external AC power source into direct current and supplying it to the energy storage device.

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