Battery pack

Abstract

The utility model discloses a battery pack, and belongs to the technical field of batteries. The battery pack comprises a box body which is provided with a bottom wall and an opening opposite to the bottom wall; the first cover body covers the opening, and an accommodating space is defined by the first cover body and the box body; the plurality of single batteries are arranged in the accommodating space, and one side, deviating from the plurality of single batteries, of the bottom wall is used for fitting an external cold plate; and the heating film is arranged on one side, facing the bottom wall, of the plurality of battery monomers. Therefore, the single batteries are arranged in the accommodating space, the bottom wall is attached to the external cold plate to enhance heat dissipation, and the heating film is positioned between the single batteries and the bottom wall to provide a heating function, so that the stable performance of the battery pack at an extreme temperature is ensured; and meanwhile, the battery pack is compact in structure and high in space utilization rate, and the safety and adaptability of the battery pack are effectively improved through dual thermal management of cooling of the cold plate and the heating film.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery pack. BACKGROUND

[0002] With the rapid development of the new energy industry, the demand for battery packs continues to grow. In order to meet the requirements of new energy vehicles for long cruising range, high safety performance and fast charging, battery packs not only need to have high energy density to extend the cruising ability, but also must achieve fast charging and discharging. This requires the battery pack to have good thermal management performance to ensure that the battery pack is always in an efficient charging and discharging temperature range.

[0003] However, in order to ensure the thermal management performance of the battery pack, a liquid cooling plate and related liquid cooling components are usually installed in the battery pack, resulting in a relatively low overall energy density of the battery pack. CONTENT OF THE UTILITY MODEL

[0004] The application provides a battery pack to solve the problem that the installation of a liquid cooling plate and related liquid cooling components in the battery pack results in a relatively low overall energy density of the battery pack.

[0005] The application provides a battery pack, comprising:

[0006] a box body having a bottom wall and an open mouth opposite to the bottom wall;

[0007] a first cover body covering the open mouth and enclosing a containing space with the box body;

[0008] a plurality of battery monomers arranged in the containing space, and a side of the bottom wall away from the plurality of battery monomers being used to fit an external cooling plate;

[0009] a heating film arranged on a side of the plurality of battery monomers facing the bottom wall.

[0010] In some embodiments, a second cover body is further arranged on a side of the plurality of battery monomers facing the first cover body, and the second cover body is an insulating cover body.

[0011] In some embodiments, a fireproof cloth is further arranged between the second cover body and the first cover body and covers at least part of the second cover body.

[0012] In some embodiments, a plurality of protrusions are arranged on a side of the bottom wall facing the plurality of battery monomers, and a first groove is formed between the protrusions;

[0013] The battery pack further comprises a structural adhesive, and the structural adhesive is contained in the first groove and bonded with the heating film.

[0014] In some embodiments, the box further has a plurality of side walls, which are arranged around the edge of the bottom wall.

[0015] The battery pack further comprises a plurality of end plates arranged between the battery monomers and the side walls.

[0016] In some embodiments, the plurality of battery monomers are arranged in a longitudinal and transverse staggered manner.

[0017] In some embodiments, the plurality of battery monomers are arranged and hollowed out on at least one side to form a placement area, and the battery pack further comprises a plug arranged in the placement area and electrically connected to the battery monomers.

[0018] In some embodiments, comprising:

[0019] A plurality of first battery groups arranged in a first direction, each of the first battery groups comprising a plurality of battery monomers arranged in a second direction, and the large faces of adjacent two battery monomers contacting each other;

[0020] A plurality of second battery groups arranged in the second direction, each of the second battery groups comprising a plurality of battery monomers arranged in the first direction, and the large faces of adjacent two battery monomers contacting each other;

[0021] The plug is arranged on one side of the plurality of first battery groups in the first direction, and at least one second battery group is arranged on both sides of the plug in the second direction.

[0022] In some embodiments, the first cover is provided with a second groove, the bottom surface of the second groove is provided with a plug connecting portion, and the plug is connected to an external circuit through the plug connecting portion.

[0023] In some embodiments, further comprising an integrated busbar bundle arranged on the side of the plurality of battery monomers facing the second cover.

[0024] Compared with the prior art, the battery pack provided by the embodiments of the present application comprises: a box having a bottom wall and an open mouth opposite to the bottom wall; a first cover arranged on the open mouth and surrounding the box to form a containing space; a plurality of battery monomers arranged in the containing space, the side of the bottom wall away from the plurality of battery monomers being used for abutting an external cold plate; and a heating film arranged on the side of the plurality of battery monomers facing the bottom wall. In this way, the battery monomers are arranged in the containing space, the bottom wall abuts the external cold plate to enhance heat dissipation, the heating film is located between the battery monomers and the bottom wall to provide heating function, and the performance stability of the battery pack under extreme temperature is ensured; at the same time, the battery pack has compact structure and high space utilization rate, and the safety and adaptability of the battery pack are effectively improved through the double thermal management of the cold plate heat dissipation and the heating film. BRIEF DESCRIPTION OF DRAWINGS

[0025] The technical solutions and other beneficial effects of the present application will be apparent from the following detailed description of the embodiments of the present application, taken in conjunction with the accompanying drawings.

[0026] Figure 1 A structural schematic diagram of a battery pack provided by an embodiment of the present application is shown in FIG. 1.

[0027] Figure 2 An exploded structural schematic diagram of a battery pack provided by an embodiment of the present application is shown in FIG. 2.

[0028] Figure 3 A structural schematic diagram of a first cover of a battery pack provided by an embodiment of the present application is shown in FIG. 3.

[0029] Figure 4 A structural schematic diagram of a box body of a battery pack provided by an embodiment of the present application is shown in FIG. 4.

[0030] Figure 5 A structural schematic diagram of a battery cell of a battery pack provided by an embodiment of the present application is shown in FIG. 5.

[0031] Figure 6 A cross-sectional structural schematic diagram of a battery pack provided by an embodiment of the present application is shown in FIG. 6.

[0032] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the present application. The present application will be described and explained with reference to the accompanying drawings in detail. DETAILED DESCRIPTION

[0033] The technical solutions and other beneficial effects of the present application will be apparent from the following detailed description of the embodiments of the present application, taken in conjunction with the accompanying drawings.

[0034] In the description of the present application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In the description of the present application, the meaning of "multiple" is two or more than two, unless otherwise explicitly specified and limited. In addition, the terms "first", "second" are for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included one or more features.

[0035] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0036] The present application provides a battery pack, please refer to Figure 1 and Figure 2 , Figure 1 schematic diagram of the structure of the battery pack provided by the embodiments of the present application; Figure 2 schematic diagram of the explosion structure of the battery pack provided by the embodiments of the present application. The battery pack provided by the present application comprises: a box body 10, a first cover body 20, a heating film 40 and a plurality of battery monomers 30. Among them, the box body 10 has a bottom wall 11 and an opening 12 opposite to the bottom wall 11; the first cover body 20 is covered on the opening 12 and forms an accommodating space 13 with the box body 10; the plurality of battery monomers 30 are arranged in the accommodating space 13, and the side of the bottom wall 11 away from the plurality of battery monomers 30 is used to fit the external cold plate; the heating film 40 is arranged on the side of the plurality of battery monomers 30 facing the bottom wall 11. Specifically, the box body 10 replaces the structural support and fixing member, and the first cover body 20 serves as the upper cover of the whole box body 10, which has high structural strength and protects the sealing property of the box body 10. In addition, the heating film 40 is arranged on the side of the plurality of battery monomers 30 facing the bottom wall 11, which occupies less space and can heat the battery monomers 30 more uniformly through bottom heating, thereby ensuring the low-temperature charging and discharging performance of the battery pack. Again, the battery monomers 30 in the present application are electrically connected through busbars, the busbars are welded with the positive and negative poles of the battery monomers 30, and the plurality of battery monomers 30 are connected in series, for example, 1 parallel 96 series.

[0037] That is, the battery pack provided by the application greatly reduces the structures such as the cross beam and the bottom plate through the arrangement scheme without the module, and does not need to set the liquid cooling and liquid heating components and the battery pack management components in the battery pack, thereby greatly improving the energy density of the battery pack. Especially, the box body 10 replaces the structural support and the fixing member, the first cover body 20 is arranged on the opening 12, and the box body 10 and the first cover body 20 enclose the containing space 13, and the plurality of battery monomers 30 are arranged in the containing space 13, so that the overall structure of the battery pack is compact, the space occupied is small, the battery pack is convenient to install and arrange in various devices, and the space utilization rate of the device is improved. At the same time, the bottom wall 11 of the box body 10 is used to adhere to the external cold plate on the side away from the plurality of battery monomers 30, so that the heat generated by the battery monomers 30 can be quickly conducted to the external cold plate, the external cold plate can be used for high-efficiency heat dissipation, the battery monomers 30 can work in the appropriate temperature range, and the performance and the service life of the battery pack are improved. In addition, the heating film 40 is arranged on the side of the plurality of battery monomers 30 facing the bottom wall 11, and when the battery pack is in a low-temperature environment, the heating film 40 can work to provide heat for the battery monomers 30, so that the performance of the battery pack is not reduced due to the low temperature, and the battery pack can normally work in different environmental temperatures.

[0038] Therefore, referring to Figure 6 , Figure 6 a cross-sectional structure of the battery pack is shown. Although the important liquid cooling and liquid heating components in the battery pack are simplified in the application to increase the energy density of the battery pack, the external cold plate, the box body 10 and the heating film 40 can replace the existing thermal management system components, and the heating film 40 and the external cold plate can be used in multiple heating and cooling modes, including low-temperature charging double heating, high-temperature charging liquid cooling, low-temperature driving single heating and the like, so that the energy density of the battery pack is improved, the use demand of the thermal management in the battery pack is met, the battery monomers 30 can be quickly raised or lowered to the appropriate temperature range, and the high-efficiency charging and discharging performance of the battery pack is ensured.

[0039] Optionally, the heating film 40 is any one of an epoxy plate heating film, a PI film or a silica gel heating film, so that the layout and the power of the heating wire are reasonably designed, the heating is fast and uniform, the temperature of the battery monomer 30 is raised in a short time, the battery monomer 30 can quickly reach the appropriate working temperature range in a low-temperature environment, the charging and discharging performance of the battery pack in the low-temperature environment is improved, the activity and the energy output efficiency of the battery pack are improved, and the service life of the battery pack is prolonged.

[0040] Therefore, referring to Figure 2In some embodiments, the battery pack further comprises a second cover 50 arranged on the side of the plurality of battery cells 30 facing the first cover 20, and the second cover 50 is an insulating cover. Specifically, the second cover 50 is an insulating cover, which can effectively isolate the first cover 20 and other structures to avoid short circuit, electric leakage and other faults between different electrical components, and ensure the electrical safety of the battery pack. In addition, the second cover 50 can play a heat preservation role for the entire battery pack, which helps to maintain the stability of the working environment temperature of the battery cells 30. In a low-temperature environment, the second cover 50 can reduce heat loss, so that the battery cells 30 can work at a suitable temperature, avoiding the performance degradation of the battery cells 30 due to too low temperature. In a high-temperature environment, the second cover 50 can also prevent external heat from entering to a certain extent, protecting the battery cells 30.

[0041] Optionally, the second cover 50 can be a polycarbonate cover or a mica cover, or other insulating covers, and the most suitable material can be selected according to actual needs, which improves the flexibility and adaptability of the battery pack design.

[0042] Please refer to Figure 2 In some embodiments, the battery pack further comprises a fireproof cloth 60 arranged between the second cover 50 and the first cover 20 and covering at least part of the second cover 50. Specifically, the fireproof cloth 60 is arranged between the second cover 50 and the first cover 20, and serves as the main protection component when the battery pack is in thermal runaway. The fireproof cloth 60 can effectively reduce the risk of the first cover 20 being burned through. When the battery pack is in a high-temperature or even fire situation due to short circuit, overcharge and other reasons, the fireproof cloth 60 can effectively prevent the spread of fire, prevent the flame from spreading from the second cover 50 to the first cover 20 and other areas of the battery pack, reduce the harm of the fire to the entire battery pack and surrounding equipment and environment, and protect the safety of personnel and property. In addition, the fireproof cloth 60 has good heat insulation performance, which can reduce the heat transfer between the second cover 50 and the first cover 20. On the one hand, it can prevent excessive heat generated during the operation of the battery pack from being dissipated to the outside of the battery pack, which helps to maintain the stability of the internal temperature of the battery pack and improves the performance and efficiency of the battery pack. On the other hand, when the external environment temperature of the battery pack is too high, the fireproof cloth 60 can also prevent a large amount of external heat from entering the battery pack, avoiding damage to the battery pack due to overheating and prolonging the service life of the battery pack.

[0043] Please refer to Figure 4 , Figure 4A structural schematic diagram of a middle box of a battery pack is shown. In some embodiments, the bottom wall 11 is provided with a plurality of protrusions 111 on a side facing the plurality of battery monomers 30, and a first groove 112 is formed between the protrusions 111; the battery pack further comprises a structural adhesive, which is accommodated in the first groove 112 and bonded with the heating film 40. Specifically, a plurality of protrusions 111 are arranged on the bottom wall 11, a first groove 112 is formed between the protrusions 111, and a structural adhesive (not shown in the figure) is accommodated in the first groove 112 and bonded with the heating film 40. In this way, the contact area of the structural adhesive with the bottom wall 11 and the heating film 40 is increased, and the connection between the heating film 40 and the bottom wall 11 is more stable. During the operation of the battery pack, whether subjected to vibration or other external forces, the heating film 40 can be firmly fixed on the bottom wall 11, ensuring the stable exertion of the heating function. Secondly, the distribution of the protrusions 111 and the first grooves 112 can be designed according to the heating characteristics of the battery monomers 30 and the heating demand, so as to guide the heating film 40 to better fit the bottom profile of the battery monomers 30, make the heating more uniform, avoid the situation of local overheating or overcooling, improve the overall heating effect and temperature consistency of the battery monomers 30, and thus improve the performance and service life of the battery pack. In addition, the first grooves 112 provide a specific accommodation space for the structural adhesive, limiting the flow range of the structural adhesive during application and curing, effectively preventing the structural adhesive from overflowing to the battery monomers 30 or other unnecessary areas, thereby avoiding pollution to the battery monomers 30 and affecting the performance of the battery pack, and also eliminating the need for additional effort to clean the overflowing structural adhesive, improving the efficiency and quality of production and assembly.

[0044] Please refer again to Figure 4 In some embodiments, the box 10 further has a plurality of side walls 14 arranged around the edges of the bottom wall 11; the battery pack further comprises a plurality of end plates 15 arranged between the battery monomers 30 and the side walls 14. Specifically, the end plates 15 are used to fill the gap between the battery monomers 30 and the side walls 14, thereby effectively reducing the relative movement between the battery monomers 30 and the side walls 14 and enhancing the overall structural strength of the battery pack. During the transportation, installation or use of the battery pack, it is inevitable to be subjected to certain vibration or external impact, and the end plates 15 can avoid the direct collision between the battery monomers 30 and the side walls 14, prevent the displacement of the battery monomers 30 under vibration or impact, improve the mechanical stability and reliability of the battery pack, and avoid the risks of shell damage, internal structure damage and other risks caused by the collision of the battery monomers 30, thereby protecting the integrity and performance of the battery monomers.

[0045] Please refer again to Figure 2In some embodiments, the battery pack further comprises a first sealing member 70 arranged between the first cover 20 and the box 10. Specifically, the first sealing member 70 can effectively prevent moisture, humidity, and the like from entering the interior of the battery pack; in the case that the battery pack may be exposed to a humid environment or face water washing, etc., preventing water from contacting the battery cells, circuitry, and other components, thereby avoiding short circuit, corrosion, and other problems, thereby protecting the electrical performance and service life of the battery pack. At the same time, the first sealing member 70 can block dust, sand, and other small foreign matter from entering the interior of the battery pack, ensuring that the interior of the battery pack remains clean and maintaining the stability of the performance of the battery pack. Optionally, the first sealing member 70 is sealing foam, so that the sealing level of the battery pack is IP67.

[0046] Referring to Figure 5 , Figure 5 A structural diagram of a battery cell of the battery pack provided by the embodiments of the present application is shown. In some embodiments, a plurality of battery cells 30 are arranged in a staggered manner. Specifically, the staggered arrangement of the battery cells 30 can better adapt to the shape of the space inside the battery pack, especially in irregularly shaped spaces, which can make full use of the corner and edge areas. Compared with parallel arrangement, more battery cells 30 can be placed in the same space, increasing the capacity of the battery pack and improving the energy density. Secondly, different application scenarios have different requirements for the size and shape of the battery pack, and the staggered arrangement of the battery cells 30 can be flexibly adjusted according to the specific space restrictions, so that the battery pack can better adapt to the specific space requirements of various devices or vehicles by changing the longitudinal and transverse ratio and arrangement of the battery cells 30, improving the versatility and applicability of the battery pack. In addition, the staggered arrangement of the battery cells 30 can make the electrical connection between the battery cells 30 more flexible and diverse, and by reasonably designing the connection lines, the connection distance between the battery cells 30 can be shortened, the resistance can be reduced, the energy loss can be reduced, and the charging and discharging efficiency of the battery pack can be improved. At the same time, it is also conducive to realizing the balanced charging and discharging between the battery cells 30, ensuring that each battery cell 30 can work in the best state, and improving the overall performance of the battery pack.

[0047] Referring again to Figure 5In some embodiments, the plurality of battery monomers 30 are arranged and hollowed on at least one side to form a placement area 31, and the battery pack further comprises a plug 80 arranged in the placement area 31 and electrically connected with the battery monomers 30. Specifically, the plug 80 is a high-low voltage plug, used for signals in the battery pack battery replacement process, and serves as the main interface for the battery pack power supply, facilitating fast battery replacement. In this way, the embodiments of the present application place the plug 80 by arranging the hollow placement area 31 in the arrangement of the battery monomers 30, which can make full use of the space inside the battery pack, avoid the plug 80 occupying additional space alone, make the structure of the battery pack more compact, realize more functions in limited space, and improve the space utilization rate of the battery pack. Secondly, the existence of the placement area 31 provides a clear position for the installation of the plug 80, which is beneficial to the overall layout planning of the components inside the battery pack, makes the structure inside the battery pack more regular and orderly, facilitates the layout and design of other components, and is also convenient for assembly operation in the production and manufacturing process.

[0048] Please refer again to Figure 5In some embodiments, the battery pack comprises a plurality of first battery groups 32 and a plurality of second battery groups 33. The plurality of first battery groups 32 are arranged along the first direction X, each first battery group 32 comprises a plurality of battery cells 30 arranged along the second direction Y, and the large faces 34 of two adjacent battery cells 30 are in contact with each other; the plurality of second battery groups 33 are arranged along the second direction Y, each second battery group 33 comprises a plurality of battery cells 30 arranged along the first direction X, and the large faces 34 of two adjacent battery cells 30 are in contact with each other; the plug 80 is arranged on one side of the plurality of first battery groups 32 along the first direction X, and along the second direction Y, at least one second battery group 33 is arranged on both sides of the plug 80. Specifically, the staggered arrangement of battery cells 30 can make full use of the internal space of the battery pack, place more battery cells 30 in a limited space, and improve the energy density of the battery pack, thereby increasing the overall power storage capacity of the battery pack. Secondly, the plug 80 is arranged on one side of the plurality of first battery groups 32 along the first direction X, and along the second direction Y, at least one second battery group 33 is arranged on both sides of the plug 80, so that the plug 80 does not occupy too much space and can be closely connected with the battery cells 30, ensuring the compactness of the overall structure of the battery pack, facilitating the connection with external equipment, and optimizing the spatial layout inside the battery pack. In addition, the large faces 34 of two adjacent battery cells 30 are in contact with each other, and this arrangement forms an effective heat dissipation channel between the battery cells 30. When the battery cells 30 work and generate heat, the heat can be transferred through the contact area of the large faces 34, and then quickly dissipated by the staggered arrangement of the first battery groups 32 and the second battery groups 33. Moreover, due to the staggered arrangement of the first battery groups 32 and the second battery groups 33, the heat can be evenly distributed throughout the battery pack, avoiding local overheating, so that each battery cell 30 works in a relatively suitable temperature environment, thereby prolonging the service life of the battery pack.

[0049] In addition, it should be noted that although the first battery group 32 and the second battery group 33 are described in the present application, the first battery group 32 and the second battery group 33 are only distinguished from the arrangement of the battery cells 30, and the battery pack is actually in the form of electrical connection between a plurality of battery cells 30, not in the form of a plurality of battery modules.

[0050] Please refer to Figure 3 , Figure 3A structural schematic diagram of a first cover of a battery pack is shown. In some embodiments, the first cover 20 is provided with a second groove 21, and the bottom surface of the second groove 21 is provided with a plug connection part 22. The plug 80 is connected to the external circuit through the plug connection part 22. Specifically, the second groove 21 ingeniously integrates the plug 80 and the plug connection part 22 in the first cover 20, avoiding the extra space occupied by the plug 80 outside the battery pack, making the overall structure of the battery pack more compact, and thus better planning the positions of other components in the limited space of the battery pack, improving the space utilization. Secondly, the plug connection part 22 is arranged at the bottom surface of the second groove 21, so that the connection line from the inside of the battery pack to the external circuit can be arranged in order along the second groove 21, reducing the disorderly entanglement of the line, helping to maintain a clean wiring environment inside the battery pack, and further optimizing the space layout inside the battery pack. In addition, the second groove 21 provides a relatively fixed position for the plug 80, reducing the possibility of the plug 80 loosening due to external factors such as vibration and shaking, ensuring that the plug 80 and the external circuit always maintain reliable electrical connection during the use of the battery pack, and ensuring the stable transmission of the battery pack power. It can be understood that the corresponding parts of the plug 80 and the plug connection part 22 are provided with a second sealing member, which can be a sealing strip or other sealing structure, to achieve an IP67 sealing level and ensure the sealing effect of the battery pack.

[0051] Please refer again to Figure 2 In some embodiments, the battery pack further includes an integrated busbar harness 90 arranged on the side of the plurality of battery cells 30 facing the second cover 50. Specifically, the integrated busbar harness includes a bracket, a conductive member arranged in the bracket and electrically connected to the battery cells, and a flexible circuit board arranged in the bracket and electrically connected to the battery cells. The integrated busbar harness 90 (CCS) generally has good electrical conductivity, which can provide a low-resistance electrical connection path between the plurality of battery cells 30 and between the battery cells 30 and other components, ensuring efficient transmission of electrical energy inside the battery pack, reducing energy loss, and improving the overall performance and efficiency of the battery pack. The flexible circuit board (FPC) monitors and controls the voltage and temperature of the battery cells 30 in real time, and transmits the collected signals to the battery management system (BMS) to manage and control the state of the battery pack, ensuring the safe and stable operation of the battery pack.

[0052] Therefore, the busbar mode of the battery pack of the application is realized by integrating the busbar wire harness 90 and the conductive part, and a bracket (not shown in the figure) is used to facilitate the welding and addressing of the pole of the battery monomer 30, reduce the welding risk, and the signal sampling lines can be regularly arranged on the busbar wire harness 90, so that the connection between the plurality of battery monomers 30 is realized in an integrated structure, greatly reducing the number and complexity of the connection lines, making the electrical connection inside the battery pack more concise and clear, and reducing the risk of poor contact, short circuit and other faults that may occur due to too many connection points. In addition, the integrated busbar wire harness 90 can be customized according to the arrangement shape and spatial position of the battery monomer 30, better fit the contour of the battery monomer 30, make full use of the space between the battery monomer 30 and the second cover 50, make the space layout inside the battery pack more compact and reasonable, help to reduce the overall volume and weight of the battery pack, and improve the integration of the battery pack in limited space.

[0053] The space utilization rate of the battery pack in the application is calculated by the following formula: module volume / PACK internal cavity volume*100. The system energy density of the battery pack is calculated by the following formula: battery capacity (Ah)*battery voltage (V) / battery weight (kg). The space utilization rate of the battery pack in the application reaches 85%, and the system energy density is 200Wh / kg. Compared with the current mainstream pure electric vehicle battery system energy density of 140-180Wh / kg, it can be seen that the system energy density of the battery pack in the application is greatly increased.

[0054] In summary, the battery monomer 30 in the application is arranged in the accommodation space 13, the bottom wall 11 is attached to the external cold plate to enhance heat dissipation, and the heating film 40 is located between the battery monomer 30 and the bottom wall 11 to provide heating function, ensuring the performance stability of the battery pack under extreme temperature; at the same time, the battery pack structure is compact, the space utilization rate is high, and the safety and adaptability of the battery pack are effectively improved through the double thermal management of the cold plate and the heating film 40.

[0055] The above describes in detail a battery pack provided by the embodiments of the application, and the principles and implementation manners of the application are described by applying specific examples. The above embodiment description is only used to help understand the technical solutions and core ideas of the application; those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A battery pack, characterized by, The battery pack comprises: a box body (10) having a bottom wall (11) and an open mouth (12) opposite to the bottom wall (11); a first cover (20) covering the open mouth (12) and forming a containing space (13) with the box body (10); a plurality of battery cells (30) arranged in the containing space (13), and the side of the bottom wall (11) away from the plurality of battery cells (30) being used for adhering to an external cold plate; a heating film (40) arranged on the side of the plurality of battery cells (30) facing the bottom wall (11).

2. The battery pack of claim 1, wherein, The battery pack further comprises a second cover (50) arranged on the side of the plurality of battery cells (30) facing the first cover (20), and the second cover (50) is an insulating cover.

3. The battery pack of claim 2, wherein, The battery pack further comprises a fireproof cloth (60) arranged between the second cover (50) and the first cover (20) and covering at least part of the second cover (50).

4. The battery pack of claim 1, wherein, The side of the bottom wall (11) facing the plurality of battery cells (30) is provided with a plurality of protrusions (111), and the protrusions (111) form a first groove (112) therebetween. The battery pack further comprises a structural adhesive contained in the first groove (112) and bonded with the heating film (40).

5. The battery pack of claim 4, wherein, The box body (10) further comprises a plurality of side walls (14) arranged around the edge of the bottom wall (11). The battery pack further comprises a plurality of end plates (15) arranged between the battery cells (30) and the side walls (14).

6. The battery pack of claim 1, wherein, The plurality of battery cells (30) are arranged in a longitudinal and transverse staggered manner.

7. The battery pack of claim 6, wherein, The plurality of battery cells (30) are arranged and hollowed out on at least one side to form a placement area (31), and the battery pack further comprises a plug (80) arranged in the placement area (31) and electrically connected with the battery cells (30).

8. The battery pack of claim 7, wherein, The battery pack comprises: a plurality of first battery groups (32) arranged in a first direction (X), each first battery group (32) comprising a plurality of battery cells (30) arranged in a second direction (Y), and the large faces (34) of adjacent two battery cells (30) being in contact with each other; a plurality of second battery groups (33) arranged in the second direction (Y), each second battery group (33) comprising a plurality of battery cells (30) arranged in the first direction (X), and the large faces (34) of adjacent two battery cells (30) being in contact with each other; the plug (80) is arranged on one side of the plurality of first battery groups (32) in the first direction (X), and at least one second battery group (33) is arranged on both sides of the plug (80) in the second direction (Y).

9. The battery pack of claim 7, wherein, The first cover (20) is provided with a second groove (21), the bottom surface of the second groove (21) is provided with a plug connecting portion (22), and the plug (80) is connected with an external circuit through the plug connecting portion (22).

10. The battery pack of claim 2, wherein, The battery pack further comprises an integrated busbar wire harness (90) arranged on the side of the plurality of battery cells (30) facing the second cover (50).

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