WO2024016908A1

WO2024016908A1 - Battery pack and electric device comprising same

Info

Publication number: WO2024016908A1
Application number: PCT/CN2023/100122
Authority: WO
Inventors: 刘斌; 陈保国; 刘峰; 蒋建云; 彭月猛; 王晨
Original assignee: 天津市捷威动力工业有限公司
Priority date: 2022-07-20
Filing date: 2023-06-14
Publication date: 2024-01-25
Also published as: CN115117510A

Abstract

The present application provides a battery pack and an electric device comprising same. The battery pack comprises a box body (1); a bottom liquid cooling plate (2), a battery module and a top liquid cooling plate (4) are sequentially stacked in the box body (1) from bottom to top; the battery module comprises at least two layers of battery units (20) sequentially stacked from bottom to top; and a middle liquid cooling plate (8) is provided between two adjacent layers of battery units (20).

Description

Battery pack and electric device including same

This disclosure claims priority to the Chinese patent application with application number 202210862295.8 filed with the China Patent Office on July 20, 2022. The entire content of the above application is incorporated into this application by reference.

Technical field

The present application belongs to the field of battery technology, for example, to a battery pack and an electric device including the same.

Background technique

With the development of the electric vehicle market, the requirements for high endurance, fast charging, high power discharge, and lifespan of batteries in the field of electric vehicles are getting higher and higher. In order to meet the needs of the market, the battery system needs to meet the requirements of large power layout, support the requirements of fast charging, support the requirements of high-rate discharge, and have a good operating temperature environment inside the battery system to improve the performance and life of the battery during use.

The battery system is designed to have high power as much as possible by increasing the system volume density to achieve high endurance requirements. In order to meet the needs of fast charging and fast discharging, high-performance products are developed for battery cells. In related technologies, hybrid electric vehicles (Hybrid Electric Vehicle) , HEV) battery cells can achieve a discharge rate of 30C (C represents the rated capacity of the battery, in ampere hours (A·h)), and pure electric vehicle (Battery Electric vehicle, BEV) batteries can achieve a charge and discharge rate of 1C-2C rate, but the heat generation of the battery core cannot be effectively controlled during rapid charging and discharging, and a thermal management system needs to be applied to dissipate heat.

For pure electric vehicles, the main heat dissipation methods used are natural heat dissipation and liquid cooling, as well as air cooling. On the basis of air cooling, direct cooling has also been developed. However, it still cannot meet the needs of the market, which requires 20 minutes (min) or less to charge 80% or fully charge. The charging rate of conventional ternary batteries is 0.5C-1C, and it takes at least 1 hour to fully charge. Moreover, ternary batteries generate a lot of heat during fast charging. In market applications, when used continuously, the internal temperature of the battery system reaches the upper limit of use. , affecting the use of the car and the life of the battery core.

Contents of the invention

In view of the deficiencies in related technologies, this application provides a battery pack and an electric device including the same. The battery pack designed in this application arranges liquid cooling plates on both sides of the battery module in the direction of maximum heat production, so that the module can dissipate heat more evenly. The overall temperature difference is smaller, which can achieve rapid heat dissipation.

In a first aspect, embodiments of the present application provide a battery pack. The battery pack includes a box body. A bottom liquid cooling plate, a battery module and a top liquid cooling plate are stacked in the box from bottom to top. The battery pack The pool module includes at least two layers of battery modules stacked sequentially from bottom to top, with a middle liquid cooling plate disposed between two adjacent layers of battery modules.

In a second aspect, embodiments of the present application provide an electric device, which includes the battery pack described in the first aspect.

Description of drawings

Figure 1 is an exploded view of a battery pack provided by an embodiment of the present application;

FIG. 2 is an exploded view of multiple parts of a battery pack provided by an embodiment of the present application.

Reference signs:

1. Box; 2. Bottom liquid cooling plate; 3. Liquid cooling tube; 4. Top liquid cooling plate; 5. Fixed rod; 6. Fixed plate; 7. First battery module; 8. Middle liquid cooling plate; 9. Second battery module; 10. Thermal conductive layer; 11. Insulation layer;

12. Bottom plate; 13. Supports; 14. Longitudinal beams;

20. Battery module; 30. Fixed components.

Detailed ways

It should be understood that in the description of this application, the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and The description is simplified and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation. Furthermore, the terms “first”, “second”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined by "first," "second," etc. may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise stated, "plurality" means two or more.

It should be noted that in the description of this application, unless otherwise clearly stated and limited, the terms "set", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the meanings of the above terms in this application can be understood through actual situations.

The technical solutions of the present application will be described below through specific implementations. The described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. The contents of the embodiments do not constitute an infringement of the present application. Limitation: Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the scope of protection of this application.

With the rapid development of social economy, electric vehicles are becoming more and more popular among consumers. Electric vehicles use battery packs as their energy source. Therefore, the use of battery packs directly determines the driving safety of electric vehicles. When the temperature of the battery module 20 in the battery pack is too high or the charging voltage is too high, it will cause many potential exothermic side effects. If the heat is not dissipated, it will cause the battery temperature to rise rapidly and thermal runaway to spread rapidly. This creates a greater safety hazard. Therefore, how to control and delay the spread of thermal runaway in battery packs has become an urgent problem to be solved.

At least in order to solve the above problems, referring to Figures 1-2, the present application provides a battery pack in one embodiment. The battery pack includes a box 1, and a bottom liquid layer is arranged in the box 1 in order from bottom to top. Cold plate 2, battery module and top liquid cooling plate 4. The battery module includes at least two layers of battery modules 20 stacked sequentially from bottom to top. A middle liquid cooling plate is provided between two adjacent layers of battery modules 20. 8.

The battery pack designed in this application arranges liquid cooling plates on both sides of the battery module 20 in the direction of maximum heat generation, so that the module can dissipate heat more evenly, and the overall temperature difference can be smaller, achieving rapid heat dissipation. Considering the demand for high battery life, when the battery pack is laid out as a two-layer battery module 20 or a multi-layer battery module 20 , the battery pack is designed as a sandwich thermal management structure, including liquid cooling plates and batteries stacked sequentially from bottom to top. Module - liquid cooling plate - battery module..., the battery module 20 in the middle is in contact with its upper and lower liquid cooling plates for heat dissipation. Compared with thermal management solutions in related technologies, this solution has doubled the contact area between the liquid cooling plate and the battery module 20. That is, when the N-layer battery module 20 is installed in the battery pack, the heat dissipation contact area of this solution is is 2N×S, and the heat dissipation area of the solution in the related art is N×S (S is the contact area between the single-layer battery module 20 and the liquid cooling plate). In addition, the thermal management structure of the multi-layer liquid cooling plate designed in this application can provide more coolant flow channels and lower flow resistance under the same inlet flow rate; under the same flow resistance requirement, it can withstand greater Import flow rate requirements. In addition, the thermal management structure of the multi-layer liquid cooling plate can improve the structural stability of the battery system.

It should be noted that the structure of the liquid cooling plate in this application can refer to liquid cooling plates that have been disclosed in related technologies or have not been disclosed in new technologies and other cooling and heat dissipation structures with similar functions. The structures of the above liquid cooling plates can be used in this application. Applying. By way of example, this application provides an optional liquid-cooling plate structure: a serpentine water-cooling flow channel is formed in the liquid-cooling plate, and an inlet joint and an outlet joint are provided on the liquid-cooling plate. A buffer layer is provided on at least one side of the liquid cooling plate. Therefore, while the liquid cooling plate cools or heats the battery module 20, the buffer layer can absorb impact energy.

It should be noted that the internal structure of the battery module 20 in the box 1 of this application can refer to the internal structure of the battery module 20 disclosed in the related art. In this application, the battery module 20 is arranged horizontally, that is, Multiple battery modules 20 are stacked along the height direction of the box 1 , so that the height requirements of the battery pack can be adaptively adjusted by adjusting the stacked thickness and number of stacked layers of the battery modules 20 . In this application, each battery module 20 optionally includes 2 to 4 single cells connected in series. The single cells can be welded or connected through positive and negative tabs. Riveting realizes electrical series connection, and increases the thickness of the battery module 20 by connecting single cells in series, thereby significantly improving the space utilization and battery capacity of the battery pack. However, too many single cells connected in series will cause the entire The battery module 20 is too thick, which increases the heat generated by the battery module 20 and is not conducive to the heat dissipation of the battery pack. Therefore, it is necessary to control the number of single cells in series to 2 to 4, so that the battery pack has a high space utilization rate. In addition to the battery capacity, the heat generation of the battery pack can also be controlled within a certain range. The length of the battery module 20 is determined by the single cell. The single cell in each battery module 20 is formed by multiple pole pieces. The longer the pole piece, the lower the yield of the battery module 20 and the unit thickness. The softer the battery module 20 is, and increasing the length of the pole pieces will significantly increase the process difficulty of stacking the pole pieces. Therefore, the length of a single battery module 20 should not be too long. In this application, by controlling the length range of the battery module 20, Ensure that the single battery core has appropriate strength.

In one embodiment, a bottom plate 12 is provided at the bottom of the box 1 , and an insulation layer 11 is provided between the bottom plate 12 and the bottom liquid cooling plate 2 .

In this application, an insulation layer 11 is provided between the bottom liquid cooling plate 2 and the bottom plate 12. On the one hand, the insulation layer 11 plays the role of thermal insulation. On the other hand, when the bottom plate 12 is deformed due to impact, the insulation layer 11 can It plays a buffering role, can protect and support the bottom liquid cooling plate 2, and weaken the impact of external impact on the bottom liquid cooling plate 2.

Optionally, the insulation layer 11 in this application is made of airgel material, and airgel has excellent thermal insulation performance. The thermal conductivity of aerogels is 2 to 3 orders of magnitude lower than that of corresponding glassy materials. By doping different substances, the radiant heat conduction of the aerogel can be reduced and the aerogel can be given different physical and chemical properties. For example, after incorporating carbon elements, the thermal conductivity of aerogels at normal temperatures and pressures can be as low as 0.013 watts per meter Kelvin (W/(m·K)), which is the lowest thermal conductivity. solid materials. After incorporating titanium dioxide, the thermal conductivity of the aerogel at 800 Kelvin (K) is only 0.03W/(m·K). In addition, aerogel has good high temperature resistance and chemical stability, and can withstand high temperatures of 1,400 degrees Celsius (℃). At the same time, aerogel is the lightest solid known so far, with a density of only 3.55 kilograms per cubic meter (kg /cm ³ ), using it in a battery pack will not have a major impact on the weight of the battery pack. Therefore, in this application, airgel material can be used to prepare the insulation layer 11, which can reduce the heat exchange efficiency and achieve better thermal insulation effect.

In one embodiment, the thermal insulation layer 11 and the bottom liquid cooling plate 2 are stacked in sequence from bottom to top and then fixed on the bottom plate 12 .

In one embodiment, the top liquid cooling plate 4 and the adjacent middle liquid cooling plate 8 are supported and fixed by a fixing assembly 30 .

This application can improve the structural stability of the battery system by arranging fixing components 30 to connect the multi-layer liquid cooling plates into a whole.

In one embodiment, the fixing assembly 30 includes fixing rods 5 located at the four corners of the middle liquid cooling plate 8 and a plurality of fixing plates 6 located at the center line of the middle liquid cooling plate 8 . The fixing rods 5 and The fixed The plate 6 is arranged between the top liquid cooling plate 4 and the middle liquid cooling plate 8 .

In one embodiment, a plurality of supporting members 13 are arranged around the inner wall of the box 1 in the horizontal direction, and the outer edge of the middle liquid cooling plate 8 is fixed on the supporting members 13 .

In this application, a support 13 is provided on the inner wall of the box 1, and the bottom surface of the box 1, the side wall of the box 1, the support 13 and the liquid cooling plate (the liquid cooling plate includes the bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top layer The liquid cooling plate 4) is built into an integrated structure, so that when the bottom surface of the box 1 is subjected to an upward concentrated load, the concentrated load can be transmitted to different liquid cooling plates through the supports 13 of different heights, and they jointly bear the concentrated load, thereby improving Battery pack resistance. In addition, since the bottom surface of the box 1, the side walls of the box 1 and the support 13 are fixedly connected, there are fixed constraints at each connection. When an upward force is exerted, the bottom surface of the box 1 is restricted to move upward due to the presence of multiple fixed constraints. The amount of bending deformation.

In one embodiment, a longitudinal beam 14 is provided on the bottom plate 12 , and the bottom surface of the middle liquid cooling plate 8 close to the bottom plate 12 is in contact and fixed with the top surface of the longitudinal beam 14 . The longitudinal beam 14 It is arranged between the bottom plate 12 and the middle liquid cooling plate 8 .

In this application, the middle liquid cooling plate 8 is fixed in the box 1 only through the longitudinal beams 14. The middle area of the middle liquid cooling plate is supported and fixed through the longitudinal beams 14, and cooperates with the support 13 located on the inner wall of the box 1. The liquid cooling plate can be supported and fixed in all directions, and the longitudinal beams 14 and supports 13 can also effectively transmit external impacts, prevent the box 1 from deforming, improve the overall structural strength of the battery pack, and improve safety; in addition, It also eliminates the numerous beams and longitudinal beams in the battery pack of related technologies, greatly saving the internal space of the box 1 and improving the space utilization of the battery pack to adapt to application scenarios with smaller installation areas.

In one embodiment, a liquid cooling pipe 3 is also provided in the box 1 , and the bottom liquid cooling plate 2 , the middle liquid cooling plate 8 and the top liquid cooling plate 4 are respectively connected to the liquid cooling pipe 3 in parallel.

In this application, the bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top liquid cooling plate 4 are arranged in parallel, and the first ends of the bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top liquid cooling plate 4 are connected to the liquid cooling The second ends of the tube 3, the bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top liquid cooling plate 4 are connected to an external heat exchange device. The bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top liquid cooling plate 4 respectively include a liquid inlet, a liquid outlet and a medium flow channel. The two ports of the medium flow channel are respectively a liquid inlet and a liquid outlet, and the liquid inlet is connected The liquid cooling pipe 3 has an inlet end connected to the water tank. The liquid cooling pipe 3 is also provided with a control valve and a delivery pump. The control valve controls the flow of coolant in the liquid cooling pipe 3. When the battery module 20 generates heat When it is too large, the coolant flow can be increased by adjusting the control valve to reduce the temperature of the battery module 20 and improve the heat dissipation efficiency. In addition, the control valve can also control the flow of coolant entering different liquid cooling plates, and individually control the flow of coolant in the corresponding liquid cooling plate according to the heat generated by different battery modules 20 . The liquid outlet of each layer of liquid cooling plate is connected to the heat exchange device. The coolant flows into the liquid cooling plate from the liquid inlet, flows out from the liquid outlet through the medium flow channel, and then enters the heat exchange device for heat exchange and cooling. For example, the liquid inlet and outlet of the liquid cooling plate are arranged on the same side of the liquid cooling plate, so that the length of the medium flow channel can be extended as much as possible, thereby increasing the heat dissipation area and improving heat dissipation efficiency.

During use, when the temperature of the single cell in the battery module 20 is too high, the coolant flows out from the water tank under the action of the transfer pump, flows into the corresponding liquid cooling plate along the liquid cooling pipe 3, and passes through the liquid cooling The plate and the battery module 20 perform heat exchange, and the heat in the battery module 20 is transferred to the coolant in the liquid cooling plate. After the normal temperature or low temperature coolant exchanges heat, the temperature rises to obtain a high-temperature coolant. The high-temperature coolant is obtained by The liquid outlet flows into the heat exchange device. After heat exchange in the heat exchange device, it cools down and becomes normal or low temperature coolant, and then flows into the water tank to realize the circulation of the coolant.

In one embodiment, between the bottom liquid cooling plate 2 and the adjacent battery module 20 , between the middle liquid cooling plate 8 and the adjacent battery module 20 , and between the top liquid cooling plate 2 and the adjacent battery module 20 , A thermal conductive layer 10 is respectively provided between the cold plate 4 and the adjacent battery module 20 .

In this application, two adjacent battery modules 20 can share a liquid cooling plate. The thermal conductive layer 10, the battery module 20 and the liquid cooling plate are in direct contact, and the heat of the battery module 20 can be directly transferred to the liquid cooling plate. board and exported, thereby performing independent cooling for each battery module 20, effectively absorbing heat from the inside of the battery module 20, and conducting the heat out of the battery in a timely manner through the cold liquid channels in each layer of liquid cooling plates. Mod 20. This allows the temperature of the cells in the battery module 20 to be evenly distributed during operation, effectively improving the usage conditions of the battery module 20 and extending the service life of the battery module 20 . Especially after thermal runaway occurs, the heat in the battery module 20 can be quickly taken away, thereby delaying the thermal runaway of the entire battery pack. It not only has high thermal conductivity efficiency, but also has a simple internal structure of the battery and is easy to assemble, and can also better Adapt to the requirement of lowering the height of the battery system. In addition, each battery module 20 is separated by providing a thermal conductive layer 10 and a liquid cooling plate to effectively reduce heat transfer between each battery module 20 . Once the temperature of a single battery module 20 is too high and a fire occurs, it can effectively slow down the transfer of flame or heat to adjacent battery modules 20, prevent the spread of hazards, and increase the emergency response time when hazards occur.

In another embodiment, the present application provides an electric device, which includes the battery pack provided in the above embodiment.

In this application, at least two layers of battery modules 20 are stacked from top to bottom in the battery pack. By increasing the number of stacked battery modules 20, the capacity in the height direction of the battery pack can be expanded, making full use of the interior of the box 1 in the height direction. space to ensure that the battery pack structure can be applied to passenger cars with a higher space under the car, and can also be adapted to large vehicles such as commercial vehicles and special vehicles that have a larger and more three-dimensional space than passenger cars. The use scenarios are wider and more practical. Sex is higher.

In one embodiment, this embodiment provides a battery pack. The battery pack includes a box 1. The bottom of the box 1 is provided with a bottom plate 12. As shown in Figures 1 and 2, the battery module includes a bottom plate 12. Two layers of battery modules 20 are stacked sequentially from top to bottom, which are the first battery module 7 and the second battery module 9 respectively. The inside of the box 1 is stacked from bottom to top with an insulation layer 11, a bottom liquid cooling plate 2, The bottom thermal conductive layer 10, the first battery module 7, the first intermediate thermal conductive layer 10, the middle liquid cooling plate 8, the second intermediate thermal conductive layer 10, the second battery module 9, the top thermal conductive layer 10 and the top liquid cooling plate 4.

The insulation layer 11 and the bottom liquid cooling plate 2 are fixed on the bottom plate 12 of the box 1 . A plurality of supports 13 are arranged on the inner wall of the box 1. The outer edge of the middle liquid cooling plate 8 is fixed on the supports 13. The bottom plate 12 is provided with a longitudinal beam 14. The bottom surface of the middle liquid cooling plate 8 is in contact with the longitudinal beam 14. The top surface is in contact and fixed, and the longitudinal beam 14 is provided between the bottom plate 12 and the middle liquid cooling plate 8 . Fixed rods 5 are provided at the four corners of the middle liquid-cooled plate 8, and a row of fixed plates 6 is provided at the center line of the middle liquid-cooled plate 8. The fixed rods 5 and the fixed plates 6 are arranged between the top liquid-cooled plate 4 and the top liquid-cooled plate 4. between the middle liquid cooling plates 8. The bottom liquid cooling plate 2, the middle liquid cooling plate 8 and the top liquid cooling plate 4 are respectively connected to the liquid cooling pipe 3 in parallel.

Claims

A battery pack. The battery pack includes a box (1). A bottom liquid cooling plate (2), a battery module and a top liquid cooling plate (4) are stacked in the box (1) from bottom to top. The battery module includes at least two layers of battery modules (20) stacked sequentially from bottom to top, and a middle liquid cooling plate (8) is provided between two adjacent layers of the battery modules (20).
The battery pack according to claim 1, wherein a bottom plate (12) is provided at the bottom of the box (1), and an insulation layer (12) is provided between the bottom plate (12) and the bottom liquid cooling plate (2). 11).
The battery pack according to claim 2, wherein the thermal insulation layer (11) and the bottom liquid cooling plate (2) are stacked in sequence from bottom to top and then fixed on the bottom plate (12).
The battery pack according to claim 1, wherein the top liquid cooling plate (4) and the adjacent middle liquid cooling plate (8) are supported and fixed by a fixing assembly (30).
The battery pack according to claim 4, wherein the fixing assembly (30) includes fixing rods (5) located at four corners of the middle liquid cooling plate (8) and a center line of the middle liquid cooling plate (8). A plurality of fixing plates (6) are provided at the fixing rod (5) and the fixing plate (6) are arranged between the top liquid cooling plate (4) and the middle liquid cooling plate (8).
The battery pack according to claim 1, wherein a plurality of supports (13) are arranged around the inner wall of the box (1) in a horizontal direction, and the outer edge of the middle liquid cooling plate (8) is fixed to the on the support (13).
The battery pack according to claim 2, wherein the bottom plate (12) is provided with a longitudinal beam (14), and the bottom surface of the middle liquid cooling plate (8) close to the bottom plate (12) is in contact with the longitudinal beam. The top surface of the beam (14) is in contact and fixed, and the longitudinal beam (14) is provided between the bottom plate (12) and the middle liquid cooling plate (8).
The battery pack according to claim 1, wherein a liquid-cooling tube (3) is further provided in the box (1), and the bottom liquid-cooling plate (2), the middle liquid-cooling plate (8) and the top liquid-cooling plate are The cold plates (4) are respectively connected in parallel to the liquid cooling tubes (3).
The battery pack according to claim 1, wherein between the bottom liquid cooling plate (2) and the adjacent battery module (20), between the middle liquid cooling plate (8) and all adjacent Thermal conductive layers (10) are respectively provided between the battery modules (20) and between the top liquid cooling plate (4) and the adjacent battery modules (20).
An electric device, which includes the battery pack according to any one of claims 1-9.