Integrated liquid-cooled battery pack

Abstract

The utility model provides an integrated liquid cooling battery pack. The integrated liquid cooling battery pack comprises a lower box body and lower heat-conducting glue arranged on a lower liquid cooling plate, the battery module comprises a first tail end and a second tail end, the first tail end is provided with a busbar connected with the positive and negative poles of the battery cell, and the second tail end is positioned on the lower heat-conducting glue; the upper liquid cooling plate is positioned at the second tail end of the battery module; the upper heat-conducting glue is arranged between the second tail end of the battery module and the upper liquid cooling plate; the box cover is connected with the lower box body and covers the battery module; the liquid cooling pipe is used for conveying cooling liquid to the upper liquid cooling plate; the liquid cooling device further comprises an elastic component arranged between the upper liquid cooling plate and the box cover, one end of the liquid cooling pipe is connected with the upper liquid cooling plate, and the other end of the liquid cooling pipe is connected with the lower liquid cooling plate. The integrated liquid-cooled battery pack disclosed by the utility model is good in liquid cooling effect, and the safety performance of the battery pack is improved.

Description

Technical Field

[0001] The utility model relates to the field of lithium-ion batteries, in particular to an integrated liquid-cooled battery pack. Background Art

[0002] In the power battery system, the excess heat generated by the battery operation will have a certain impact on the battery life and user experience. At present, the power batteries used in electric vehicles are mainly lithium-ion batteries that are sensitive to temperature changes. The temperature inside the battery pack has a great impact on the reliability, life and performance of the battery cell, so the battery thermal management system has become an important guarantee for the operation of new energy vehicles.

[0003] According to the market and communication and research with many customers, the market's requirements for high cycle life of square hard-shell lithium batteries are constantly increasing. How to improve the heat transfer of battery packs is crucial to solving the current market's requirement for battery systems to achieve high cycle life.

[0004] The heat of the battery in the liquid-cooled battery pack can be transferred through the contact between the battery pack (or battery cell) and the surface of the liquid cooling plate, and the battery temperature can be reduced by circulating the coolant in the liquid cooling plate. However, the contact method between the liquid cooling plate and the various components of the battery cell in the battery pack, as well as the specific cooling effect of the liquid cooling plate, will greatly affect the heat conduction efficiency in the battery pack. Therefore, how to reasonably set the connection method between the liquid cooling plate and the battery cell in the battery pack and improve the liquid cooling effect of the liquid cooling plate is crucial to improving the cycle life of the battery pack, and is an urgent problem to be solved. Utility Model Content

[0005] In order to enhance the liquid cooling effect of a liquid-cooled battery pack and increase the cycle life of the battery pack, the utility model provides an integrated liquid-cooled battery pack, comprising: a lower box body, comprising a lower liquid cooling plate and a cooling liquid inlet and a cooling liquid outlet; a lower thermally conductive adhesive arranged on the lower liquid cooling plate; a battery module, comprising a first end and a second end, the first end being provided with a bus connected to the positive and negative poles of the battery cell, and the second end being located on the lower thermally conductive adhesive; an upper liquid cooling plate, located at the second end of the battery module; an upper thermally conductive adhesive, arranged between the second end of the battery module and the upper liquid cooling plate; a box cover, constructed to be connected to the lower box body and cover the battery module; a liquid cooling pipe, used to transport cooling liquid to the upper liquid cooling plate; and also comprising an elastic member arranged between the upper liquid cooling plate and the box cover, one end of the liquid cooling pipe being connected to the upper liquid cooling plate, and the other end of the liquid cooling pipe being connected to the lower liquid cooling plate.

[0006] Further, the elastic member is configured to support foam.

[0007] Furthermore, a plurality of supporting foams are provided.

[0008] Furthermore, a layer of insulating film is arranged outside the upper thermal conductive adhesive.

[0009] Furthermore, the surface of the upper liquid cooling plate is provided with insulating paint.

[0010] Furthermore, there are multiple upper liquid cooling plates.

[0011] Furthermore, the upper liquid cooling plate is constructed in a U shape.

[0012] Furthermore, the liquid cooling pipe includes a coolant inlet pipe and a coolant outlet pipe, the coolant inlet pipe is connected to the coolant input port, and the coolant outlet pipe is connected to the coolant outlet port.

[0013] Furthermore, the cooling liquid inlet pipe includes a cooling liquid inlet main pipe and a plurality of cooling liquid inlet branch pipes, and the plurality of cooling liquid inlet branch pipes are respectively connected to the plurality of upper liquid cooling plates.

[0014] Furthermore, the upper liquid cooling plate includes an upper liquid cooling plate cooling liquid inlet and an upper liquid cooling plate cooling liquid outlet, the upper cooling liquid inlet branch pipe is connected to the upper liquid cooling plate cooling liquid inlet; the upper cooling liquid outlet branch pipe is connected to the upper liquid cooling plate cooling liquid outlet.

[0015] The integrated liquid-cooled battery pack of the utility model is provided with liquid cooling plates at both ends of the battery module for cooling, and has a good cooling effect; and an elastic member is provided between the upper liquid cooling plate and the battery box cover, so that the gap between the upper thermal conductive glue and the battery module bus is reduced, thereby improving the electrical safety performance of the battery pack. The battery pack adopting the solution of the utility model significantly improves the heat transfer effect and electrical safety of the battery pack, and increases the cycle life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the integrated liquid-cooled battery pack of the utility model;

[0017] Figure 2 This is an exploded schematic diagram of the integrated liquid-cooled battery pack of the utility model;

[0018] Figure 3 It is a schematic diagram of the liquid cooling system in the integrated liquid cooling package of the utility model;

[0019] Figure 4 This is a schematic diagram of the structure of the lower liquid cooling plate of the integrated liquid cooling package of the utility model;

[0020] Figure 5 It is a cross-sectional view of the upper liquid cooling plate of the integrated liquid cooling package of the utility model;

[0021] Figure 6 It is a schematic diagram of the upper liquid cooling plate of the integrated liquid cooling package of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0023] like Figure 1-6 As shown, the integrated liquid-cooled battery of the present invention includes: a lower box body 20 , a box cover 10 , a battery module 30 , an upper liquid cooling plate 40 , a liquid cooling pipe 50 , an upper thermal conductive adhesive 70 and a lower thermal conductive adhesive 60 .

[0024] like Figure 2 As shown, the integrated liquid-cooled battery pack of the utility model includes a plurality of battery modules 30, each of which includes a plurality of single cells, and a buffer foam (not shown) is arranged between the single cells to absorb the expansion of the cells due to heat. An end plate is arranged at both ends of each battery module 30 to fix the plurality of cells between the two end plates, and a tie 301 is also arranged on the outside of each battery module to bundle the cells in the module into an independent battery module. A bus bar 90 is also arranged at the upper end of each battery module 30, and the bus bar 90 is directly welded to the positive and negative poles of each cell to connect the positive and negative poles of the cell in series and parallel. In the utility model, a pit is arranged at a position corresponding to the positive and negative poles of the cell on the bus bar 90, so that the welding point between the cell pole and the bus bar can be arranged at the pit to prevent the solder at the welding point from flying to other places of the cell and affecting the performance of the cell.

[0025] like Figure 4 As shown, the lower box 20 of the utility model is generally rectangular in shape, preferably made of aluminum, and of course, optionally, can also be made of other materials. The lower box 20 includes a lower liquid cooling plate 205, a lower liquid cooling plate coolant inlet 201, a lower liquid cooling plate coolant outlet 202, a liquid cooling tube coolant inlet 203, and a liquid cooling tube coolant outlet 204. The lower liquid cooling plate 205 is generally planar in shape, and can be used to support the second end of the battery cell of the battery module, and is provided with a coolant liquid flow channel for the coolant to circulate to cool the second end of the battery module.

[0026] like Figure 3As shown, the liquid cooling pipe 50 includes a coolant inlet pipe 501 and a coolant outlet pipe 502; the liquid cooling pipe 50 is configured as a whole to be composed of a flexible material so that the shape of the liquid cooling pipe can be changed according to the installation requirements to adapt to the specific installation position of the liquid cooling plate. In this embodiment, the coolant inlet pipe 501 and the coolant outlet pipe 502 are independently arranged, and the coolant inlet pipe 501 is used to flow uncooled fresh coolant into the upper liquid cooling plate 40. The coolant outlet pipe 502 is used to discharge the cooled liquid from the upper liquid cooling plate to the outside of the battery pack. The coolant outlet pipe 502 includes a coolant outlet pipe branch 5022 and a coolant outlet pipe main pipe 5021; the coolant inlet pipe 501 includes a coolant inlet pipe branch 5012 and a coolant inlet pipe main pipe 5011. A plurality of coolant inlet branches 5012 are provided, which can be respectively connected to a plurality of upper liquid cooling plates 40 to input the coolant into each upper liquid cooling plate 40. A plurality of cooling liquid outflow branches 5022 are provided, which can be respectively connected to a plurality of upper liquid cooling plates 40 to discharge the cooling liquid from each upper liquid cooling plate 40 to a cooling liquid outlet.

[0027] like Figure 4-5 As shown, the upper liquid cooling plate 40 is U-shaped as a whole, made of aluminum, and the outermost layer of the liquid cooling plate is sprayed with insulating paint. Preferably, the upper liquid cooling plate is provided with two cavities, such as Figure 5 The first cavity 401 and the second cavity 402 shown are configured as liquid flow channels, and the upper liquid cooling plate coolant inlet 404 and the upper liquid cooling plate coolant outlet 405 are provided at the first end of the upper liquid cooling plate 40. In this embodiment, the upper liquid cooling plate coolant inlet 404 and the upper liquid cooling plate coolant outlet 405 are provided on the same side of the upper liquid cooling plate 40. Specifically, the coolant inlet pipe branch 5012 is connected to the coolant inlet 404 of the upper liquid cooling plate, and the coolant outlet pipe 5022 is connected to the coolant outlet 405 of the upper liquid cooling plate 40. This arrangement is conducive to the connection and installation of the liquid cooling pipe 50 and multiple upper liquid cooling plates 40, so that the coolant can flow in and out on the same side of the upper liquid cooling plate 40, which not only enhances the cooling effect of the coolant, but also improves the space utilization of the battery pack. In the battery pack of this embodiment, multiple upper liquid cooling plates 40 are provided, and the multiple upper liquid cooling plates 40 are respectively connected to different cooling liquid inflow branches 5012 and cooling liquid outflow branches 5022. Each upper liquid cooling plate can obtain fresh cooling liquid in time, so that the busbar on the battery module can be cooled in time. The cooling effect is better than that of only providing a large liquid cooling plate. The first end of the upper liquid cooling plate 40 is also provided with a first fixing hole 403, and the second end of the upper liquid cooling plate 40 is also provided with a second fixing hole 407, which can be passed through the first fixing hole 403 and the second fixing hole 407 by fasteners such as bolts or screws to the end plate of the battery module (not shown).

[0028] The integrated liquid-cooled battery pack of the utility model can be assembled according to the following steps:

[0029] A layer of lower thermally conductive adhesive 60 is laid on the upper surface of the lower liquid cooling plate 20, and the lower thermally conductive adhesive is made of insulating flame-retardant material; the second end of the battery module is then set on the lower thermally conductive adhesive 60, so that the lower thermally conductive adhesive 60 is located between the lower liquid cooling plate 205 and the battery cell of the battery module 30; then the upper thermally conductive adhesive 70 is installed above the bus 90 of the battery module, and the upper thermally conductive adhesive 70 is composed of thermally conductive silicone and an insulating film; the upper liquid cooling plate 40 is then placed above the upper thermally conductive adhesive 70, and finally the first fixing hole 406 and the second fixing hole 407 on the upper liquid cooling plate 40 are fixedly connected to the two side end plates of the battery module with bolts; then the elastic member 80 is placed above the upper liquid cooling plate, and finally the box cover 10 is closed on the lower box body.

[0030] In the present invention, an elastic member 80 is provided between the upper liquid cooling plate 40 and the box cover 10. The elastic member is preferably configured as a supporting foam. Optionally, the elastic member 80 may also be configured in other forms, such as sponge, spring, flexible vertical material, etc. In this embodiment, the box cover 10 squeezes the supporting foam so that the supporting foam generates pressure to squeeze the upper liquid cooling plate 40, so that the upper liquid cooling plate 40 is fully in contact with the upper thermal conductive adhesive 70. At the same time, the upper liquid cooling plate 40 squeezes the upper thermal conductive adhesive 70 and empties the gap between the bus 90 and the upper thermal conductive adhesive 70, thereby further increasing the thermal contact area between the upper liquid cooling plate 40 and the battery, thereby improving the cooling effect of the battery pack, thereby improving the electrical performance of the battery module.

[0031] In the embodiment of the utility model, the upper thermal conductive adhesive 70 is provided with an insulating film outside the separate thermal conductive silicone pad; at the same time, the outer surface of the upper liquid cooling plate is sprayed with insulating paint; these two insulating measures between the insulating film of the upper thermal conductive adhesive and the insulating paint of the upper liquid cooling plate greatly reduce the electrical gap between the upper liquid cooling plate and the bus, ensuring the high-voltage safety of the battery pack. Furthermore, the upper thermal conductive adhesive uses a non-flowable thermal conductive silicone pad, which is simple in process and easy to install compared to the flowable thermal conductive silicone or thermal conductive gel commonly used in the prior art.

[0032] In an embodiment of the utility model, an upper liquid cooling plate is provided at the upper end of the battery module. The coolant flowing through the upper liquid cooling plate can have a good cooling effect on the bus on the battery module. The heat generated on the bus on the battery module can be efficiently cooled by the bus, thereby significantly improving the current carrying capacity of the bus. Therefore, the bus in the battery pack of the utility model can be designed to be smaller than the bus of the natural heat dissipation type, so as to reduce the cross-section of the bus, save the material used for the bus, and reduce the material cost.

[0033] The integrated liquid-cooled battery pack of the utility model is provided with liquid cooling plates at the upper and lower ends of the battery module for cooling, so that the cooling effect can be achieved at the upper and lower ends of the battery at the same time, which increases the uniformity of the temperature of the battery cells and avoids the technical problem of large temperature difference between the upper and lower parts of the battery cells caused by liquid cooling at only one end of the battery pack and no liquid cooling at the other end. Therefore, the battery pack can maintain a relatively comfortable high cycle life working condition even in harsh temperature and environment.

[0034] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention.

[0035] It is not a limitation of the implementation methods of the utility model. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. An integrated liquid-cooled battery pack, comprising: The lower box body includes a lower liquid cooling plate and a coolant inlet and a coolant outlet; A lower thermally conductive adhesive disposed on the lower liquid cooling plate; The battery module comprises a first end and a second end, wherein the first end is provided with a busbar connected to the positive and negative poles of the battery cell, and the second end is located on the lower thermal conductive adhesive; an upper liquid cooling plate, located at the second end of the battery module; An upper thermally conductive adhesive is disposed between the second end of the battery module and the upper liquid cooling plate; A box cover, configured to be connected to the lower box body and cover the battery module; A liquid cooling pipe, used for conveying cooling liquid to the upper liquid cooling plate; It is characterized in that it also includes an elastic component arranged between the upper liquid cooling plate and the box cover, one end of the liquid cooling tube is connected to the upper liquid cooling plate, and the other end of the liquid cooling tube is connected to the lower liquid cooling plate.

2. The integrated liquid-cooled battery pack according to claim 1, characterized in that: The elastic member is configured to support foam.

3. The integrated liquid-cooled battery pack according to claim 2, characterized in that: The supporting foam is provided in plurality.

4. The integrated liquid-cooled battery pack according to claim 1, characterized in that: A layer of insulating film is arranged outside the upper thermal conductive adhesive.

5. The integrated liquid-cooled battery pack according to claim 1, characterized in that: The surface of the upper liquid cooling plate is provided with insulating paint.

6. The integrated liquid-cooled battery pack according to claim 1, characterized in that: The upper liquid cooling plate is provided in plurality.

7. The integrated liquid-cooled battery pack according to claim 1, characterized in that: The upper liquid cooling plate is configured in a U shape.

8. The integrated liquid-cooled battery pack according to claim 1, characterized in that: The liquid cooling pipe includes a cooling liquid inlet pipe and a cooling liquid outlet pipe. The cooling liquid inlet pipe is connected to the cooling liquid input port, and the cooling liquid outlet pipe is connected to the cooling liquid outlet port.

9. The integrated liquid-cooled battery pack according to claim 8, characterized in that: The cooling liquid inflow pipe includes a cooling liquid inflow main pipe and a plurality of cooling liquid inflow branch pipes, and the plurality of cooling liquid inflow branch pipes are respectively connected to the plurality of upper liquid cooling plates.

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