CTP cylindrical battery system

Abstract

The utility model discloses a CTP cylindrical battery system which comprises a box body, at least one battery module arranged in the box body and a direct cooling plate upper cover, the battery module comprises a plurality of cylindrical battery cells, and a heat conduction layer is arranged between a busbar at the top of the battery module and the direct cooling plate upper cover. And the direct cooling plate upper cover exchanges heat with the top of the battery module through the heat conducting layer. According to the CTP cylindrical battery system disclosed by the utility model, the heat conduction layer is arranged between the busbar at the top of the battery module and the direct cooling plate upper cover, so that the direct cooling plate upper cover exchanges heat with the busbar at the top of the battery module through the heat conduction layer; therefore, the problems that the busbar at the top of the cylindrical battery of the battery pack formed by the large cylindrical battery in the prior art is relatively high in temperature rise, the top cannot be cooled, and the use safety of the battery is influenced are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical battery packs, in particular to a CTP cylindrical battery system. Background Art

[0002] In the application of refrigerant direct cooling technology, different automobile manufacturers have adopted different technical methods to cool cylindrical batteries. However, cylindrical batteries still use serpentine flat tube liquid cooling. This cooling method requires more thermal management related components, occupies a large space, has more internal connection pipes, and all are rigidly connected; due to the structural characteristics of cylindrical batteries, the electrical connections of large cylindrical batteries are currently at the top, and the temperature of the bus is relatively high. The current serpentine tube cooling solution cannot cool the top of the battery cell and the bus, and cannot alleviate the problem of excessive temperature rise of the bus caused by fast charging and other working conditions. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings and defects of the prior art and to provide a CTP cylindrical battery system, which aims to solve the problem that the busbars of the cylindrical battery are all connected to the top of the battery cell, the busbars in some positions carry a large current and the temperature rises too fast, which is prone to thermal safety problems.

[0004] A CTP cylindrical battery system comprises a box, at least one battery module placed in the box and a direct cooling plate upper cover, wherein the battery module comprises a plurality of cylindrical cells, a heat conducting layer is arranged between a bus bar at the top of the battery module and the direct cooling plate upper cover, and the direct cooling plate upper cover performs heat exchange with the bus bar at the top of the battery module through the heat conducting layer.

[0005] Wherein, the heat conductive layer is connected to the upper cover of the direct cooling plate and / or the busbar of the battery module by using a heat conductive adhesive.

[0006] Wherein, the heat-conducting layer is formed by bonding an upper heating film and a lower heat-conducting pad together.

[0007] Wherein, the upper heating film and the lower thermal pad are bonded together by thermally conductive adhesive.

[0008] The battery module includes a bottom bracket, and the upper surface of the bottom bracket has a plurality of openings corresponding to the battery cells one by one, which are used for defusing explosions when thermal runaway occurs.

[0009] The battery module includes two oppositely arranged side brackets located outside the battery cell stack, which are fixed to the busbar bracket on the top of the battery cell and the bottom bracket to form an integral frame to limit and protect the battery cell stack.

[0010] The busbar of the battery module is embedded in the busbar bracket, and the battery module further includes an FFC located on the inner side of the side bracket and between the side bracket and the battery cell.

[0011] The upper cover of the direct cooling plate is formed by connecting a flow channel plate and a cooling plate, and the height of the stamped flow channel inside the upper cover is ≤2.5mm and the width is ≤15mm.

[0012] A BDU area and an LMU area are formed inside the box, and the BDU area and the LMU area are arranged opposite to each other and located at two ends of the battery module.

[0013] Wherein, a coolant interface is arranged outside the box.

[0014] In the CTP cylindrical battery system of the utility model, a heat-conducting layer is arranged between the bus bar on the top of the battery module and the upper cover of the direct cooling plate. The upper cover of the direct cooling plate exchanges heat with the top of the battery module through the heat-conducting layer, thereby solving the problem that the bus bar on the top of the cylindrical battery of the battery pack composed of large cylindrical batteries in the prior art has a high temperature rise and cannot be cooled from the top, which affects the safety of battery use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an exploded view of the CTP cylindrical battery system of the utility model.

[0016] Figure 2 This is an exploded view of the battery module of the CTP cylindrical battery system of the present invention.

[0017] Figure 3 This is a schematic diagram of the bottom bracket of the CTP cylindrical battery system of the utility model on the connecting plate.

[0018] Figure 4 It is a top view of the CTP cylindrical battery system of the present utility model.

[0019] Description of reference numerals:

[0020] 1-direct cooling plate upper cover; 2-heat conducting layer; 3-battery module; 4-box;

[0021] 11-flow channel plate; 12-cooling plate; 13-stamping flow channel;

[0022] 31-busbar; 32-busbar bracket; 33 battery cell; 34-FFC; 35-side bracket; 36-bottom bracket; 361-opening;

[0023] 41-coolant interface, 42-connecting plate. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] like Figures 1 to 4 As shown, the CTP cylindrical battery system of an embodiment of the utility model includes a box body 4, at least one battery module 3 placed in the box body and a direct cooling plate upper cover 1, wherein the battery module includes a plurality of cylindrical battery cells 33, and a heat conductive layer 2 is arranged between the bus 31 on the top of the battery module and the direct cooling plate upper cover 1, and the direct cooling plate upper cover 1 performs heat exchange with the bus 31 on the top of the battery module 3 through the heat conductive layer 3.

[0026] In some embodiments, the heat conductive layer 2 is connected to the upper cover of the direct cooling plate and / or the bus of the battery module by using a thermal conductive adhesive. Preferably, the heat conductive layer is formed as an integral sheet body, and each battery module is equipped with one heat conductive layer.

[0027] Among them, the thermally conductive adhesive is preferably a thermally conductive gel, which can effectively fill the gaps and has a soft texture, making it easy to disassemble and repair; in the present application, since the direct cooling method is used for cooling, and direct cooling has a fast cooling rate and can effectively control the temperature rise, it has the effect of quickly cooling the bus position, and at the same time, the heat transfer of the bus can be used to cool the battery cell synchronously.

[0028] In a preferred embodiment, the thermal conductive layer 2 is formed by bonding an upper heating film and a lower thermal conductive pad together. By bonding the upper heating film together, it is possible to reduce the on-site assembly process when assembling the battery pack and improve assembly efficiency. The upper heating film is provided with a heating plate, which can be heated when the battery needs to be heated. When the battery needs to be directly cooled, it does not work. The upper thermal conductive pad can achieve heat transfer during real cooling or heating. Optionally, the upper heating film and the lower thermal conductive pad are bonded together by thermal conductive adhesive. Since the thermal conductive layer 2 is formed by bonding an upper heating film and a lower thermal conductive pad together, the flexible characteristics of the lower thermal conductive pad can be used to effectively fill the gap at the bottom of the bus, increase the contact area, and improve the heat dissipation effect.

[0029] In some embodiments, the battery module 3 includes a bottom bracket 36, and the upper surface of the bottom bracket 36 has a plurality of openings 361 corresponding one-to-one to the battery cells, which are used for explosion disposal when thermal runaway occurs. The bottom bracket can also realize the positioning of multiple battery cells during assembly, so that the battery arrangement meets the preset requirements. Therefore, preferably, the opening is a stepped hole, consisting of an upper large diameter hole and a lower small diameter hole. The upper large diameter hole is adapted to the outer diameter of the cylindrical battery cell, so as to realize the positioning of the battery cell, and the lower small diameter hole is used for explosion disposal of thermal runaway as an explosion disposal hole.

[0030] In some embodiments, Figure 3 As shown, a plurality of connecting plates 42 are provided in the box body 4, the bottom bracket 36 is fixed on the connected connecting plates 42, and there is a gap between the bottom bracket 36 and the inner surface of the bottom of the box body 4, and the gap is connected to the explosion-proof valve of the box body. When the battery cell thermally runs away, the gas can be discharged from the explosion-proof valve through the gap.

[0031] In some embodiments, the battery module 3 includes two oppositely arranged side brackets 35 located on the outside of the battery cell stack, which are fixed to the bus bracket 32 ​​on the top of the battery cell and the bottom bracket 36 as an integral frame to limit and protect the battery cell stack. The structural design of the integral frame provides better strength support and can provide impact protection for the battery cell. In addition, the battery module also includes FFC (Flexible Flat Cable) 34, which is located on the inner side of the side bracket 35, that is, between the side bracket and the battery cell. In this application, the cooling system is concentrated on the top of the battery module and the FFC is placed on the side, which can reduce the space occupied in the height direction of the battery module. In addition, the FFC is set on the side to enable the thermal conductive gel to directly contact the bus, thereby improving the cooling effect.

[0032] In the cylindrical electric system of the present application, the entire battery module is welded at the upper end of the cylindrical battery cell, the bus is relatively concentrated, and the special size of the cylindrical battery cell determines that the bus shape is unconventional. Therefore, a bus bracket 32 ​​is provided and the bus 31 is embedded therein to ensure that the upper surface is as flat as possible, increase the heat transfer area, and facilitate heating and cooling.

[0033] In some implementation schemes, the bottom bracket, the side bracket and the bus bracket are fixed by bolts, and may also be fixed by other means.

[0034] In the present application, the battery module is limited by the bottom bracket, the side bracket and the bus bracket to form an integral module. After being loaded into the box, it can be connected by bolts, that is, bolted to the box. The bottom of the box can be fixed with a connecting plate 42 that is convenient for bolting the battery module 3, such as bolting to the box through the bottom bracket. The connecting plate 42 is a sheet metal bending component with a certain height, so the gas discharged from the bottom is discharged from the middle of the two connecting plates 42.

[0035] In some embodiments, the upper cover 1 of the direct cooling plate is formed by connecting the flow channel plate 11 and the cooling plate 12, and the height of the stamped flow channel 13 inside is ≤2.5mm and the width is ≤15mm. The flow channel plate is located in the upper layer, and the cooling plate is located in the lower layer. The flow channel plate is formed by integral stamping, and a flow channel groove is formed on the surface. After being composite-sealed and connected with the cooling plate (such as by brazing), a flow channel is formed inside. The thickness of the flow channel plate is 1.0-1.5mm, and the coolant in the flow channel can be 50% ethylene glycol, R134a, with a working pressure range of 0.03-1.3MPa, a pressure resistance of ≤4MPa, and a bursting pressure of ≤9MPa. The above parameter range meets the pressure resistance and temperature uniformity performance requirements of liquid cooling and direct cooling; the stamped flow channel can provide certain reinforcement for the upper cover and act as a reinforcing rib. The upper cover 1 of the direct cooling plate is fixed to the box body 3 by bolting. This is a prior art structure and will not be repeated here.

[0036] In some embodiments, Figure 4 As shown, a BDU (Battery Disconnect Unit, a distribution box designed inside the battery pack, which can perform switching operations on the battery circuit according to the operating mode of the electric vehicle (such as charging status or driving status)) area and an LMU (Local Monitoring Unit) area are formed inside the box. The BDU area and the LMU area are relatively arranged, located at both ends of the battery module, between the BDU area and the LMU area and the battery module placement area, and separated by a partition. The BDU area and the LMU area are independent space structures. Such a design makes the overall space utilization of the box higher, which is conducive to improving the grouping rate.

[0037] In some embodiments, a coolant interface 41 is arranged on the outside of the box body 4, that is, a coolant interface is provided on the outside of the battery pack and is connected to an external coolant source to provide coolant to the upper cover of the direct cooling plate and for the circulation of the coolant. By arranging the coolant interface on the outside of the box body, the internal volume of the box body is not occupied, and no pipelines are arranged inside the battery pack of the present application, and the volume inside the pack is not occupied. The box space utilization rate is high, and the separation of the coolant and the circuit inside the pack is truly realized, thereby avoiding the safety hazard of short circuit in the battery pack due to leakage caused by poor sealing.

[0038] From the above description, it can be seen that the technology of the utility model can realize the cooling of the top bus of the large cylindrical battery, solve the problem of high and rapid temperature rise at the top bus position of the large cylindrical battery, and at the same time eliminate the cooling pipeline inside the original battery pack system, thereby improving the grouping rate and eliminating the internal cooling pipeline, thereby improving the safety of the entire pack and avoiding the risk of short circuit.

[0039] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.

[0040] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. CTP cylindrical battery system, characterized in that: It includes a box body, at least one battery module placed in the box body and a direct cooling plate upper cover, the battery module includes a plurality of cylindrical battery cells, a heat conductive layer is arranged between the bus bar on the top of the battery module and the direct cooling plate upper cover, and the direct cooling plate upper cover performs heat exchange with the bus bar on the top of the battery module through the heat conductive layer.

2. The CTP cylindrical battery system according to claim 1, characterized in that: The heat-conducting layer is connected to the upper cover of the direct cooling plate and / or the busbar of the battery module by using a heat-conducting adhesive.

3. The CTP cylindrical battery system according to claim 1, characterized in that: The heat-conducting layer is formed by bonding an upper heating film and a lower heat-conducting pad together.

4. The CTP cylindrical battery system according to claim 3, characterized in that: The upper heating film and the lower heat conductive pad are bonded together by heat conductive adhesive.

5. The CTP cylindrical battery system according to claim 1, characterized in that: The battery module comprises a bottom bracket, and an upper surface of the bottom bracket has a plurality of openings corresponding to the battery cells one by one, which are used for defusing explosions when thermal runaway occurs.

6. The CTP cylindrical battery system according to claim 1, characterized in that: The battery module includes two side brackets arranged opposite to each other on the outside of the battery cell stack, which are fixed to the busbar bracket on the top of the battery cell and the bottom bracket to form an integral frame to limit and protect the battery cell stack.

7. The CTP cylindrical battery system according to claim 6, characterized in that: The busbar of the battery module is embedded in the busbar bracket, and the battery module further includes an FFC located on the inner side of the side bracket and between the side bracket and the battery cell.

8. The CTP cylindrical battery system according to claim 1, characterized in that: The upper cover of the direct cooling plate is formed by connecting a flow channel plate and a cooling plate, and the height of the stamped flow channel inside the upper cover is ≤2.5mm and the width is ≤15mm.

9. The CTP cylindrical battery system according to claim 1, characterized in that: A BDU area and an LMU area are formed inside the box, and the BDU area and the LMU area are arranged opposite to each other and located at two ends of the battery module.

10. The CTP cylindrical battery system according to claim 1, characterized in that: A coolant interface is arranged outside the box.

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