Three-face liquid cooling CTP battery pack

Abstract

The utility model discloses a three-side liquid cooling CTP battery pack which comprises a battery box body liquid cooling bottom plate and a battery cell side surface liquid cooling assembly fixed on the upper surface of the battery box body liquid cooling bottom plate, and the battery cell side surface liquid cooling assembly comprises a plurality of side surface liquid cooling plates which are arranged in parallel at intervals; battery cell units are respectively arranged in a plurality of U-shaped spaces formed between the adjacent side surface liquid cooling plates, and the two ends of the plurality of side surface liquid cooling plates are fixedly connected with the fixed end plates. According to the utility model, the battery box body liquid cooling bottom plate and the battery core side surface liquid cooling assembly are adopted to form a three-surface liquid cooling system, so that the heat dissipation rate of the battery core is increased, the temperature difference of the battery system is reduced, the thermal management requirement of the battery can be met, the battery box body liquid cooling bottom plate is simultaneously used as a battery box body bottom plate, and the energy density is improved by the CTP integrated design.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, in particular to a three-sided liquid-cooled CTP battery pack. Background Art

[0002] As the core power of new energy vehicles, people have higher and higher requirements for battery packs. In order to make new energy vehicles travel more mileage with the same energy consumption, higher requirements are put forward for the improvement of the energy density of battery packs. At the same time, the demand for fast charging and high power increases the heat generation of batteries. Therefore, how to make the battery dissipate heat efficiently has become an important research topic.

[0003] Most of the existing battery packs are MTP (Module To Pack) solutions, which combine the battery packs into modules, and then place the battery modules one by one in the battery box and fix them with bolts. This solution has a cumbersome production process, low efficiency, and high labor costs; at the same time, it adds materials such as module end plates and side plates, which reduces the energy density of the battery pack and increases material costs. In addition, the existing thermal management solutions for battery packs are mostly natural cooling or liquid cooling at the bottom of the battery pack. There is a 1C charging and discharging demand during the use of the current battery, and the heat generation is higher. Relying solely on natural cooling or bottom liquid cooling can no longer meet the temperature requirements of the battery cell. If the battery cell is in a high temperature environment for a long time, it will affect the performance of the battery cell and even have the risk of thermal runaway. For this reason, people have proposed a CTP (Cell TOPACK) battery pack. However, the existing CTP (Cell To Pack) battery packs are mostly equipped with horizontal and longitudinal beams inside the battery box, and the battery cell units are squeezed into the box, which has higher requirements for equipment and site, and the cost of rework after entering the box is high. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies and defects of the prior art and to provide a three-sided liquid-cooled CTP battery pack.

[0005] A three-sided liquid-cooled CTP battery pack comprises a battery box liquid-cooled bottom plate and a cell side liquid-cooled assembly fixed to the upper surface of the battery box liquid-cooled bottom plate, wherein the cell side liquid-cooled assembly comprises a plurality of parallel and spaced side liquid-cooled plates, wherein a plurality of U-shaped spaces formed between adjacent side liquid-cooled plates are each provided with a cell unit, and both ends of the plurality of side liquid-cooled plates are connected and fixed to fixed end plates.

[0006] Wherein, the side liquid cooling plate and the outer surface of the battery cell of the battery cell unit are fixed by a heat-conducting structural adhesive.

[0007] Wherein, the liquid-cooled bottom plate of the battery box is fixed to the bottom of the battery cell of the battery cell unit by means of a thermally conductive structural adhesive.

[0008] The battery cell unit is composed of a plurality of arranged battery cells, and the battery cells are bonded and fixed with inter-cell fillers.

[0009] Among them, the cooling liquid flow channels of the liquid cooling assembly on the side of the battery cell and the liquid cooling bottom plate of the battery box are linear.

[0010] Among them, the outer sides of the two outer liquid cooling plates located on the outer sides of the side liquid cooling plates have a first fixed boss, which is used to cooperate with the second fixed boss in the length direction of the upper surface of the liquid cooling bottom plate of the battery box body, and is supported and limited at the bottom by the second fixed boss. A plurality of first fixing holes are arranged on the first fixed boss, and second fixing holes corresponding to the first fixing holes are arranged on the second fixed boss; after the first fixing holes correspond to the second fixing holes, bolts are installed to fix them.

[0011] Among them, each of the two ends of the side liquid cooling plate has a third fixing hole, and the fixed end plate has multiple fourth fixing holes that match the third fixing holes. After the third fixing holes are aligned with the fourth fixing holes, bolts are installed to connect and fix the side liquid cooling plate and the fixed end plate.

[0012] Among them, the front end and the rear end of the side liquid cooling plate are respectively arranged with a first water pipe joint, and the battery box liquid cooling bottom plate is arranged with a water inlet, a water outlet and a second water pipe joint of the battery pack; the second water pipe joint is connected to the first water pipe joint at the front end of the battery cell side liquid cooling assembly through a front end water pipe assembly; the first water pipe joint at the rear end of the side liquid cooling plate is connected through a rear end water pipe assembly.

[0013] Therein, a first limiting hole is provided in the middle of the fixed end plate for the first water pipe joint to extend out, and limiting grooves are provided at both ends for limiting the first water pipe joint on the outside.

[0014] Among them, the three-sided liquid-cooled CTP battery pack includes a battery box upper cover, which cooperates with the battery box liquid-cooled bottom plate and the vertical plate at the front end of the battery box liquid-cooled bottom plate to form a space, and the battery cell side liquid cooling assembly and the battery cell unit are covered in the space; the water inlet and outlet of the battery pack are arranged on the outer side of the vertical plate.

[0015] The utility model adopts a battery box liquid cooling bottom plate and a cell side liquid cooling component to form a three-sided liquid cooling system. The cell side liquid cooling component increases the heat dissipation of the cell side, increases the heat dissipation rate of the cell, reduces the temperature difference of the battery system, and can meet the thermal management requirements of the battery. The battery box liquid cooling bottom plate also serves as the battery box bottom plate, and the CTP integrated design improves the energy density. The side liquid cooling plate can be used as a cell unit side plate while providing a coolant flow channel as a liquid cooling plate, thereby enhancing the mechanical strength of the battery pack. No horizontal or vertical beams are provided in the battery box, and the CTP grouping is simple. The cell entry method does not use extrusion of the cell into the battery box, and is easier to disassemble, saving assembly equipment costs and rework costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an exploded view of the battery pack of the embodiment of the present utility model.

[0017] Figure 2 It is a schematic diagram of the flow of coolant in the liquid cooling assembly and water pipe assembly on the side of the battery cell of the battery pack of the embodiment of the utility model.

[0018] Figure 3 It is a schematic diagram of the flow of cooling liquid in the liquid-cooled bottom plate of the battery box of the battery pack of the embodiment of the utility model.

[0019] Figure 4 It is a schematic diagram of the liquid cooling assembly on the side of the battery cell of the battery pack according to an embodiment of the utility model.

[0020] Figure 5 It is a schematic diagram of the outer liquid cooling plate of the battery pack according to an embodiment of the present utility model.

[0021] Figure 6 It is a schematic diagram of a liquid-cooled bottom plate of a battery box of a battery pack according to an embodiment of the utility model.

[0022] Figure 7 It is a schematic diagram of the connection of the front end water pipe assembly of the battery pack according to an embodiment of the utility model.

[0023] Figure 8 It is a schematic diagram of the connection of the rear end water pipe assembly of the battery pack of an embodiment of the utility model.

[0024] Description of reference numerals:

[0025] 1-Battery box cover;

[0026] 2-battery cell unit;

[0027] 3-Liquid cooling assembly on the side of the battery cell;

[0028] 31-outer liquid cooling plate; 32-middle liquid cooling plate; 33-fixed end plate; 34-fastener;

[0029] 311 - third fixing hole; 312 - first water pipe joint; 313 - flow channel; 314 - first fixing hole; 315 - first fixing boss;

[0030] 4-Liquid cooling base plate of battery box;

[0031] 41 - water inlet; 42 - water outlet; 43 - second water pipe joint; 44 - second fixing hole; 45 - second fixing boss;

[0032] 5- Water pipe assembly;

[0033] 51 - water pipe; 52 - quick-insert water pipe connector; 53 - front-end water pipe assembly; 54 - rear-end water pipe assembly. DETAILED DESCRIPTION

[0034] 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.

[0035] like Figures 1 to 8 As shown, the three-sided liquid-cooled CTP battery pack of the embodiment of the utility model includes a battery box liquid-cooled bottom plate 4 and a cell side liquid-cooled assembly 3 fixed to the upper surface of the battery box liquid-cooled bottom plate 4, which become the main body of the liquid cooling system of the battery pack. The cell side liquid-cooled assembly includes a plurality of parallel and spaced side liquid-cooled plates, and a plurality of U-shaped spaces formed between adjacent side liquid-cooled plates are each arranged with a cell unit 2, and the two ends of the plurality of side liquid-cooled plates are connected and fixed to the fixed end plate 33. The liquid cooling system of the battery pack circulates the selected coolant in the cooling channels of the battery box liquid-cooled bottom plate and the cell side liquid-cooled assembly, transferring and taking away the heat of the cell unit 2, thereby realizing the function of cooling the battery pack.

[0036] The side liquid cooling plate is composed of an outer liquid cooling plate 31 and an intermediate liquid cooling plate 32. There are two outer liquid cooling plates 31 arranged on the outside, and the inner side is in contact with the battery cell of the battery cell unit for liquid cooling. There are multiple intermediate liquid cooling plates 32, and the two sides thereof are in contact with the battery cell of the battery cell unit for liquid cooling. Optionally, the main bodies of the outer liquid cooling plate 31 and the intermediate liquid cooling plate 32 are both extruded profiles, which can be used as side plates of the battery cell unit 2 while providing a coolant flow channel as a liquid cooling plate, thereby enhancing the mechanical strength of the battery pack.

[0037] In order to more stably fix the battery cell unit 2, in one embodiment, the side liquid cooling plate (i.e., the outer liquid cooling plate 31 and the middle liquid cooling plate 32) and the outer surface of the battery cell of the battery cell unit 2 are fixed by thermally conductive structural adhesive. Fixing by thermally conductive adhesive does not affect the thermal conductivity and does not affect the liquid cooling effect.

[0038] In order to more stably fix the battery cell unit 2, in one embodiment, the battery box liquid cooling bottom plate 4 is fixed to the bottom of the battery cell of the battery cell unit 3 by thermally conductive structural glue. In the present application, in addition to the side liquid cooling plate and the battery cell of the battery cell unit being fixed by thermally conductive glue, the bottom of the battery cell is also fixed to the battery box liquid cooling bottom plate 4 by thermally conductive glue, which can better fix the battery cell unit without affecting the thermal conductivity and liquid cooling effect.

[0039] Wherein, the battery cell unit is composed of a plurality of battery cells arranged longitudinally. In order to stabilize the battery cells, in the present application, preferably, the battery cells are bonded and fixed with inter-cell fillers.

[0040] In a preferred embodiment, the coolant flow channels of the liquid cooling assembly on the side of the battery cell and the liquid cooling bottom plate of the battery box are linear. The coolant passes through the linear flow channels with low resistance, smooth flow, and good liquid cooling effect. The linear flow channels can enable the coolant to circulate quickly, which is conducive to rapid heat dissipation.

[0041] In a preferred embodiment, the front end and the rear end of the side liquid cooling plate are respectively arranged with a corresponding first water pipe joint 312, the first water pipe joint 312 is welded to the front end and the rear end of the side liquid cooling plate, and is communicated with the internal flow channel 313, and a channel for circulating the coolant is formed through the water pipe assembly 5 connected to the front and rear ends, and the liquid cooling medium flows to the direction such as Figure 5 As shown by the arrows; in order to facilitate the connection of an external cold source system, a water inlet 41 and a water outlet 42 of the battery pack and two second water pipe joints 43 are arranged on the liquid cooling bottom plate 4 of the battery box; wherein, the water inlet 41 and the water outlet 42 are correspondingly connected with the two first water pipe joints 312 for water inlet and water return at the front end of the battery cell side liquid cooling assembly 3 through the two second water pipe joints 43 and the front end water pipe assembly 53, and the first water pipe joint 312 at the rear end of the side liquid cooling plate is connected through the rear end water pipe assembly 54, so that the coolant can reflux at the rear end of the side liquid cooling plate to form a circulation.

[0042] Among them, when the coolant of the battery pack is circulating, the coolant enters the liquid cooling system from the external liquid cooling unit through the water inlet 41, enters the liquid cooling bottom plate 4 of the battery box, passes through the water pipe assembly 5 connected to the flow channel of the liquid cooling system, is diverted into the liquid cooling assembly 3 on the side of the battery cell, passes through the entire battery system liquid cooling flow channel, and then returns to the water outlet 42 at the front end of the battery pack, flows into the external liquid cooling unit, and completes the circulation of the coolant.

[0043] Among them, the water inlet flow channel and the water return flow channel inside the liquid cooling bottom plate 4 of the battery box body are connected to the water inlet 41 and the water outlet 42 on the liquid cooling bottom plate 4 of the battery box body. The two second water pipe joints 43 for water inlet and water return of the battery cell side liquid cooling assembly 3 are arranged on the inner side of the water inlet 41 and the water outlet 42. The two second water pipe joints 43 include a water inlet pipe joint and a water return pipe joint. The two second water pipe joints 43 are connected to the front end water pipe assembly 53 accordingly, so as to realize the connection between the water inlet 41 and the water outlet 42 and the two first water pipe joints 312 at the front end of the battery cell side liquid cooling assembly In this way, when the external coolant enters, it enters through the water inlet 41, first enters the battery box liquid cooling bottom plate 4 and enters the internal flow channel of the battery box liquid cooling bottom plate 4, and is divided through the second water pipe joint 43 for water inlet and the corresponding front end water inlet pipe assembly, and enters the corresponding first water pipe joint 312, and enters the coolant flow channel of the liquid cooling assembly 3 on the side of the battery cell, and finally returns at the rear end of the liquid cooling assembly 3 on the side of the battery cell and the liquid cooling bottom plate 4 of the battery box, and flows back to the second water pipe joint 43 for water return through the corresponding first water pipe joint 312 for water return and the front end water pipe assembly 53, and finally flows out from the water outlet 42 to form a cycle.

[0044] In one embodiment, a limiting hole for the first water pipe connector 312 to extend out is provided in the middle of the two fixed end plates 32 arranged at the front and rear ends of the battery pack, and limiting grooves are formed at both ends to limit the outer first water pipe connector 312 .

[0045] In a preferred embodiment, the water pipe assembly 5 of the present application, such as the front water pipe assembly 53 and the rear water pipe assembly 54, both include a water pipe 51 and a quick-insert water pipe joint 52. The quick-insert water pipe joint 52 connects the corresponding water pipe 51 to the first water pipe joint / second water pipe joint on the battery box liquid cooling bottom plate 4 / cell side liquid cooling assembly 3, so as to form a passage for the circulation of the coolant. The use of quick-insert water pipe joints can reduce the difficulty of assembly, make the structure simple, and facilitate maintenance.

[0046] In order to better fix the cell side liquid cooling assembly 3, the outer sides of the two outer liquid cooling plates 32 are provided with a first fixing boss 315, and the first fixing boss 315 is used to limit the second fixing boss 45 in the length direction of the upper surface of the liquid cooling bottom plate of the battery box, and is supported and limited at the bottom by the second fixing boss 45. A plurality of first fixing holes 314 are arranged on the first fixing boss 315, and second fixing holes 44 corresponding to the first fixing holes 314 are arranged on the second fixing boss; after the first fixing hole corresponds to the second fixing hole, bolts are inserted to fix them, thereby fixing the cell side liquid cooling assembly 3 to the liquid cooling bottom plate 4 of the battery box, and the second fixing boss 45 cooperates with the first fixing boss 315 to limit the height direction.

[0047] In order to fix the side liquid cooling plate of the cell side liquid cooling assembly 3 to the fixed end plate 32 to form a stable structure, each of the two ends of the side liquid cooling plate has a third fixing hole 311, and the fixed end plate has a plurality of fourth fixing holes (no longer marked) that match the third fixing holes. After the third fixing holes and the fourth fixing holes are aligned, the fasteners 34 are inserted to connect and fix the side liquid cooling plate and the fixed end plate 32. The fasteners 34 are used to stably fix the cell side liquid cooling assembly 3 and the cell unit 2 to the liquid cooling bottom plate 4 of the battery box through the first fixing hole 314 and the second fixing hole 44. The fixed end plate 32 is fastened with bolts when the cell is under pressure, so that the cell is under a specified pre-tightening pressure state, which can improve the cycle performance; and the fixed end plate is fastened with bolts, which is convenient for disassembly and has low later maintenance costs.

[0048] When assembling the battery pack of the present application, the battery cell unit 2 is first combined with the middle liquid cooling plate and the outer liquid cooling plate using a thermally conductive structural adhesive. The use of thermally conductive structural adhesive can enhance the structural strength and ensure good thermal conductivity between the side of the battery cell and the liquid cooling plate. Before the thermally conductive structural adhesive is cured, the fixed end plate 33 is installed and fixed and extruded so that the battery cell is under a specified extrusion force and fixed with a fastener 34. As the thermally conductive structural adhesive is cured, the battery cell unit 2 and the liquid cooling assembly 3 on the side of the battery cell will form a whole. The thermally conductive structural adhesive can ensure good thermal conductivity between the bottom of the battery cell and the liquid cooling bottom plate of the battery box 4, and has sufficient bonding strength. In this way, the battery cell unit is bonded to the liquid cooling bottom plate of the battery box and the liquid cooling assembly on the side of the battery cell using a thermally conductive structural adhesive, and then fasteners 34 (bolts) are used for secondary fixation, which increases the structural strength of the battery pack, and the CTP grouping technology further increases the energy density of the battery pack.

[0049] Among them, the three-sided liquid-cooled CTP battery pack also includes a battery box upper cover 1, and the battery box upper cover 1 cooperates with the battery box liquid-cooled bottom plate 4 and the vertical plate 46 at the front end of the battery box liquid-cooled bottom plate to form a space, and the battery cell side liquid cooling component 3 and the battery cell unit 2, and the water pipe component 5 are covered in the space; the outer side of the vertical plate is arranged with a water inlet 41 and a water outlet 42 of the battery pack.

[0050] In the present application, a three-sided liquid cooling system is formed by a liquid-cooled bottom plate of the battery box, a liquid-cooling assembly on the side of the battery cell, and a water pipe assembly. In addition to conventional bottom liquid cooling, the liquid-cooling assembly on the side of the battery cell increases the heat dissipation on the side of the battery cell, increases the heat dissipation rate of the battery cell, reduces the temperature difference of the battery system, and can meet the thermal management requirements of the battery.

[0051] In this application, since the liquid cooling bottom plate of the battery box at the bottom also serves as the bottom plate of the battery box, the integrated design improves the energy density. Compared with the conventional CTP battery pack, the CTP box of the present application is provided with horizontal and longitudinal beams, and the battery cell unit is squeezed into the box, which saves the materials such as the end plate, side plate, and steel belt in the conventional group design, and further improves the energy density of the battery pack; the grouping form using bolts is simple and easier to disassemble, which saves the assembly equipment cost and rework cost, and has the characteristics of simple grouping, easy assembly and disassembly.

[0052] Since the liquid cooling assembly on the side of the battery cell can serve as a liquid cooling plate to provide a coolant flow channel, it can also serve as a side plate of the battery cell unit to enhance the mechanical strength of the battery pack. The liquid cooling assembly on the side of the battery cell and the bottom liquid cooling plate are bonded with thermally conductive structural adhesive, and then fixed again with bolts, which makes the mechanical strength of the battery pack higher.

[0053] The above shows and describes the basic principle 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.

[0054] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0055] 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. Three-sided liquid-cooled CTP battery pack, characterized by: It includes a battery box liquid-cooled bottom plate and a battery cell side liquid-cooled assembly fixed to the upper surface of the battery box liquid-cooled bottom plate, the battery cell side liquid-cooled assembly includes a plurality of parallel and spaced side liquid-cooled plates, a plurality of U-shaped spaces formed between adjacent side liquid-cooled plates are each provided with a battery cell unit, and both ends of the plurality of side liquid-cooled plates are connected and fixed to fixed end plates.

2. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The side liquid cooling plate is fixed to the outer surface of the battery cell of the battery cell unit by means of a heat-conducting structural adhesive.

3. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The liquid-cooling bottom plate of the battery box is fixed to the bottom of the battery cell of the battery cell unit by means of a heat-conducting structural adhesive.

4. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The battery cell unit is composed of a plurality of battery cells arranged in an array, and the battery cells are bonded and fixed with inter-cell fillers.

5. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The cooling liquid flow channels of the battery cell side liquid cooling assembly and the liquid cooling bottom plate of the battery box are linear.

6. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The outer sides of the two outer liquid cooling plates located on the outer sides of the side liquid cooling plates are provided with a first fixing boss, which is used to cooperate with the second fixing boss on the length direction of the upper surface of the liquid cooling bottom plate of the battery box body, and is supported and limited at the bottom by the second fixing boss. A plurality of first fixing holes are arranged on the first fixing boss, and second fixing holes corresponding to the first fixing holes are arranged on the second fixing boss; after the first fixing holes correspond to the second fixing holes, bolts are installed to fix them.

7. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: Each of the two ends of the side liquid cooling plate has a third fixing hole, and the fixed end plate has multiple fourth fixing holes that match the third fixing holes. After the third fixing holes are aligned with the fourth fixing holes, bolts are installed to connect and fix the side liquid cooling plate and the fixed end plate.

8. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: The front end and rear end of the side liquid cooling plate are respectively arranged with a first water pipe joint, and the battery box liquid cooling bottom plate is arranged with a water inlet, a water outlet and a second water pipe joint of the battery pack; the second water pipe joint is connected to the first water pipe joint at the front end of the battery cell side liquid cooling assembly through a front end water pipe assembly; the first water pipe joint at the rear end of the side liquid cooling plate is connected through a rear end water pipe assembly.

9. The three-sided liquid-cooled CTP battery pack according to claim 8, characterized in that: The fixed end plate has a first limiting hole in the middle for the first water pipe joint to extend out, and limiting grooves at both ends for limiting the first water pipe joint on the outside.

10. The three-sided liquid-cooled CTP battery pack according to claim 1, characterized in that: It includes a battery box upper cover, which cooperates with the battery box liquid cooling bottom plate and the vertical plate at the front end of the battery box liquid cooling bottom plate to form a space, and the battery cell side liquid cooling assembly and the battery cell unit are covered in the space; the outer side of the vertical plate is arranged with a water inlet and a water outlet of the battery pack.

Images