Battery pack, energy storage system and electric device

Abstract

A battery pack, an energy storage system and an electric device. In the battery pack, a heating assembly (20) is provided between two adjacent columns of battery cells (10), a heating portion (202) and a buffer portion (201) are stacked in a first direction, the heating portion (202) is adapted to heat the battery cells (10) and the buffer portion (201), and the buffer portion (201) is adapted to shrink under pressure and expand under heat so as to flexibly deform, and the heating assembly (20) fits with the battery cells (10).

Description

Battery packs, energy storage systems, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number "202420290049.4" filed by Contemporary Amperex Technology Co., Ltd. on February 8, 2024, entitled "Battery Pack, Energy Storage System and Electrical Device." Technical Field

[0003] The present application relates to the technical field of battery packs, and in particular to a battery pack, an energy storage system, and an electrical device. Background Art

[0004] The battery cells in the battery pack need to control the operating temperature at an appropriate temperature. If the temperature is too high, there is a risk of thermal runaway, and if the temperature is too low, the capacity of the battery pack will be attenuated (that is, the battery life in daily life will be reduced).

[0005] In related technologies, battery cells are cooled by liquid cooling plates, and heated by providing heating films, heating patches and other structures. The heating films, heating patches and battery cells are in close contact with each other to transfer heat. However, battery cells expand and contract during the charging and discharging process, which may cause the battery cells to be loosely fitted with the heating films and heating patches, resulting in dry burning. This will not only reduce the reliability of the battery pack, but also lead to poor heating performance.

[0006] Summary of the Invention

[0007] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a battery pack, an energy storage system, and an electrical device, wherein the battery pack has a better heating effect and higher reliability.

[0008] A battery pack comprises: battery cells and a heating assembly, wherein there are multiple battery cells, and the multiple battery cells are arranged in columns along a first direction and in rows along a second direction, the first direction is orthogonal to the second direction, the heating assembly is arranged between two adjacent columns of the battery cells, the heating assembly comprises a heating portion and a buffer portion extending along the second direction, the heating portion and the buffer portion are stacked in the first direction, the heating portion is suitable for heating the battery cells and the buffer portion, the buffer portion is suitable for shrinking under pressure and expanding under heat to deform flexibly, and the heating assembly is fitted to the battery cells.

[0009] Therefore, the heating component includes a heating part and a buffer part. The buffer part and the battery cell can be heated by the heating part, and the buffer part can produce flexible deformation, which can not only make the battery cell and the heating component fit better, thereby reducing the probability of dry burning of the heating component, improving the safety and reliability of the battery pack, and reducing safety hazards, but also when the battery cell is deformed, the area of ​​the heat conduction interface between the heating component and the battery cell can be kept stable, which can further improve the heating effect and heating efficiency of the heating component.

[0010] According to some embodiments of the present application, the heating component includes: a substrate and a flexible membrane located on both sides of the substrate, the flexible membrane is sealed to the substrate, a buffering heat-conducting medium is filled between the substrate and the flexible membrane, the buffering heat-conducting medium and the flexible membrane define the buffer portion, and a heating element is embedded in the substrate to define the heating portion.

[0011] According to some embodiments of the present application, the buffering heat-conducting medium is configured as an insulating coolant.

[0012] According to some embodiments of the present application, the heating portion is configured as a positive temperature coefficient thermistor.

[0013] According to some embodiments of the present application, the heating assembly includes a buffer layer and heating films located on both sides of the buffer layer, the buffer layer defines the buffer portion, and the heating film defines the heating portion.

[0014] According to some embodiments of the present application, the buffer layer is constructed as a foam layer.

[0015] According to some embodiments of the present application, the buffer layer includes: a first sub-buffer layer and second sub-buffer layers located on both sides of the first sub-buffer layer, and the first sub-buffer layer and the second sub-buffer layer are made of different materials.

[0016] According to some embodiments of the present application, the first sub-buffer layer is configured as an airbag layer.

[0017] According to some embodiments of the present application, the second sub-buffer layer is constructed as a foam layer.

[0018] According to some embodiments of the present application, the airbag layer has a plurality of airbags filled with a heat-expandable medium. According to some embodiments of the present application, the size of the heating component in the first direction is 0.5 mm to 20 mm.

[0019] According to some embodiments of the present application, end plates are further provided at both ends of each column of battery cells in the second direction, and ends of the buffer portion in the second direction are connected to the end plates via fasteners.

[0020] According to some embodiments of the present application, the heating assembly further includes: a connecting plate, the connecting plate extending along the first direction, and the ends of the buffer portions adjacent to each other in the first direction are connected via the connecting plate.

[0021] An energy storage system includes: the battery pack described in the above embodiment.

[0022] An electrical device includes the battery pack described in the above embodiment.

[0023] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] FIG1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0026] FIG2 is a schematic diagram of a battery according to an embodiment of the present application;

[0027] FIG3 is a schematic diagram of a disassembled box according to an embodiment of the present application;

[0028] FIG4 is a schematic diagram of a disassembled support plate according to an embodiment of the present application;

[0029] FIG5 is a schematic diagram of a plate body structure according to the first embodiment of the application;

[0030] FIG6 is a schematic diagram of another plate body structure according to the first embodiment of the present application;

[0031] FIG7 is a schematic diagram of a plate body structure according to a second embodiment of the present application;

[0032] FIG8 is a partial schematic diagram of the cooperation between a support plate and a frame according to an embodiment of the present application;

[0033] FIG9 is a partial schematic diagram of another embodiment of the present application showing the cooperation between the support plate and the frame;

[0034] FIG10 is a partial enlarged schematic diagram of a plate body according to an embodiment of the present application;

[0035] FIG11 is a cross-sectional view of a reinforcement plate according to an embodiment of the present application;

[0036] FIG12 is a cross-sectional view of another reinforcing plate according to an embodiment of the present application;

[0037] FIG13 is a cross-sectional view of another reinforcement plate according to an embodiment of the present application. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0040] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0042] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0043] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In the description of the present application, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features being in contact with each other not directly but via another feature therebetween.

[0046] In the description of this application, a first feature “on”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0047] The term "plurality" used in this application refers to two or more (including two).

[0048] In the embodiment of the present application, the heating component 20 can be used to heat the battery cell 10. In some severely cold usage environments, such as the usage scenario in the north in winter, the ambient temperature is low, which will cause the activation energy of the electrolyte inside the battery cell 10 to decrease, and the efficiency of the battery cell 10 to decrease. By setting up the heating component 20, the temperature of the battery cell 10 can be adjusted by the heating component 20, and the battery cell 10 can be heated to improve the efficiency of the battery cell 10 in a low temperature environment, reduce the attenuation of the energy storage capacity of the battery cell 10 in a cold environment, and improve the usage experience.

[0049] The battery cell 10 may be a secondary battery. A secondary battery refers to a battery cell 10 that can be continuously used by activating active materials by charging after the battery cell 10 is discharged.

[0050] The battery cell 10 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0051] The battery pack 100 mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells 10 to provide higher voltage and capacity. When there are multiple battery cells 10, the multiple battery cells 10 are connected in series, in parallel, or in hybrid through a busbar.

[0052] In some embodiments, a plurality of battery cells 10 may be combined into a battery module 600 . That is, when there are a plurality of battery cells 10 , the plurality of battery cells 10 are arranged and fixed to form a battery module 600 .

[0053] In some embodiments, the battery pack 100 includes a case 500 and a battery cell 10, at least one battery cell 10 or at least one battery module 600 is accommodated in the case 500, and the case 500 has an accommodating space, and at least one battery cell 10 or at least one battery module 600 is accommodated in the accommodating space.

[0054] In some embodiments, the box 500 can be used as part of the chassis structure of the vehicle. For example, part of the box 500 can become at least a part of the floor of the vehicle, or part of the box 500 can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0055] In some embodiments, the battery pack 100 or the battery module 600 may be part of an energy storage system, which may be an energy storage container, an energy storage cabinet, etc., in which batteries and energy shutdown modules are integrated.

[0056] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety performance of the battery also needs to be considered.

[0057] Because the energy we need is highly temporal and spatially dependent, in order to rationally utilize and improve energy efficiency, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form, and then release it in a specific form based on future application needs. As we all know, achieving the goal of carbon neutrality currently relies primarily on replacing fossil energy with green energy to generate green electricity.

[0058] Current green energy sources mainly include solar energy, wind energy, and hydropower. However, solar energy and wind energy generally have problems of strong intermittency and large volatility, which will cause unstable voltage of the green power grid (insufficient electricity during peak hours and too much electricity during low hours). Unstable voltage will cause damage to electricity. Therefore, it may cause the problem of "wind and solar power curtailment" due to insufficient electricity demand or insufficient grid acceptance capacity.

[0059] To address the issue of insufficient electricity demand or insufficient grid capacity, energy storage systems are essential. These systems convert electrical energy into other forms of energy through physical or chemical means, storing it. When needed, the stored energy is converted back into electricity and released. Simply put, an energy storage system acts like a large "power bank," storing electricity when there's sufficient solar or wind energy and releasing it when needed.

[0060] Currently, energy storage (i.e., energy storage) has a wide range of application scenarios, including power generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding energy storage system types include:

[0061] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation;

[0062] (2) The main operating mode of small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side and small household energy storage boxes used in home energy storage scenarios on the user side is "peak shaving and valley filling". Since there is a large price difference in electricity prices at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, they release the electricity in the energy storage equipment for use, so as to achieve the purpose of saving electricity bills. In addition, in remote areas, as well as areas with high incidence of natural disasters such as earthquakes and hurricanes, the existence of household energy storage systems is equivalent to users providing themselves and the power grid with backup power, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0063] In conjunction with the aforementioned physical or electrochemical energy storage, taking electrochemical energy storage as an example, the energy storage system can include at least one battery as described above, utilizing the chemical elements within the battery as the energy storage medium, with the charging and discharging process achieved through chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by solar and wind energy is stored in at least one battery through chemical reactions or changes in the energy storage medium. When external power usage reaches a peak, the energy stored in the at least one battery is released through chemical reactions or changes in the energy storage medium for use, or transferred to areas with power shortages for use.

[0064] The battery cell 10 serves as the smallest energy unit of the battery module 600, the battery pack 100, and the energy storage system. The battery module 600 or the battery pack 100 includes multiple battery cells 10. The battery cell 10 includes a large battery surface defined by the width edge and the length edge of the battery cell 10, a small battery surface defined by the width edge and the height edge, and a battery end surface defined by the length edge and the width edge. In order to enable the battery cell 10 to be used in a cold environment, a thermal film can be attached to the surface of the battery cell 10 (such as the large battery surface, the small battery surface or the battery end surface).

[0065] The heating film is attached to the surface of the battery cell 10. During the charging and discharging process, the battery cell 10 expands and contracts, which may cause the heating film to lose contact with the battery cell 10, resulting in the risk of dry burning or tearing of the heating film, posing a safety hazard and reducing the heating effect and efficiency.

[0066] An embodiment of the present application provides a battery pack 100, in which the heating component 20 in the battery pack 100 can produce adaptive deformation based on the expansion and contraction of the battery cells 10 in the battery pack 100, so that the heating component 20 and the battery cells 10 are more closely fitted, which can not only improve the heating effect and heating efficiency, but also reduce the risk of dry burning and reduce safety hazards.

[0067] The technical solutions described in the embodiments of the present application are applicable to the battery pack 100 and the electrical device 200 using the battery pack 100 .

[0068] The electrical device 200 can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railway use, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical device 200.

[0069] For the convenience of description, the following embodiments are described by taking the electric device 200 as a vehicle as an example.

[0070] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided by some embodiments of the present application. A battery pack 100 is disposed within the vehicle, and battery pack 100 can be located at the bottom, front, or rear of the vehicle. Battery pack 100 can be used to power the vehicle, for example, as the vehicle's operating power source.

[0071] The vehicle may further include a controller 300 and a motor 400 . The controller 300 is used to control the battery pack 100 to supply power to the motor 400 . The motor 400 serves as a load, for example, to meet the power requirements for starting, navigating, and driving the vehicle.

[0072] In some embodiments of the present application, the battery pack 100 can not only serve as the operating power source of the vehicle, but also serve as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0073] Please refer to Figure 2, which is an exploded view of a battery pack 100 provided in some embodiments of the present application. The battery pack 100 includes a battery module 600 and a box 500, and the box 500 is used to accommodate the battery module 600.

[0074] The case 500 is a component that houses the battery module 600. The case 500 provides storage space for the multiple battery cells 10 within the battery module 600. The case 500 can adopt various structures. In some embodiments, the case 500 can include a tray and the case 500. The tray and the case 500 cover each other to define a storage space for accommodating the battery cells 10. The tray and the case 500 can be of various shapes, such as a rectangular parallelepiped, a cylinder, etc. The tray can be a hollow structure with one side open, and the case 500 can also be a hollow structure with one side open. The open side of the case 500 covers the open side of the tray, forming a case 500 with a storage space. Alternatively, the tray can be a hollow structure with one side open, and the case 500 can be a plate-like structure. The case 500 covers the open side of the tray, forming a case 500 with a storage space. As an example, the battery cell 10 may be a cylindrical battery cell 10 , a prismatic battery cell 10 , a soft-pack battery cell 10 , or a battery cell 10 in another shape, which is not particularly limited in the present application.

[0075] In the battery pack 100, there can be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations within the multiple battery cells 10. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid configuration to form a battery module 600. The multiple battery modules 600 are then connected in series, parallel, or in a hybrid configuration to form a single unit and housed within the housing 500. Alternatively, all battery cells 10 can be directly connected in series, parallel, or in a hybrid configuration, and then the entire unit formed by all battery cells 10 is housed within the housing 500.

[0076] The following describes a battery pack 100, an energy storage system, and an electrical device 200 according to an embodiment of the present application with reference to Figures 1 to 13.

[0077] As shown in Figures 2 and 12, the present application provides a battery pack 100, including: battery cells 10 and heating components 20. The heating components 20 can be arranged between adjacent battery cells 10, such as between the large battery surfaces of adjacent battery cells 10, between the small battery surfaces of adjacent battery cells 10, and between the battery end surfaces of adjacent battery cells 10, so as to heat the battery cells 10 through the heating components 20, increase the operating temperature of the battery cells 10, increase the activation energy of the electrolyte in the battery cells 10, reduce the endurance discount of the battery cells 10, and improve the energy storage capacity attenuation of the battery cells 10.

[0078] There are multiple battery cells 10 in the battery pack 100. The multiple battery cells 10 can be arranged in an array, or the multiple battery cells 10 can form at least one battery module 600. A battery module 600 has multiple single cells arranged in an array or a single row. The single cells are connected in series, in parallel or in a mixed manner to output electrical energy according to the required voltage.

[0079] There are a plurality of battery cells 10 , and the battery cells 10 are arranged in columns along a first direction and in rows along a second direction, and the first direction is orthogonal to the second direction.

[0080] For example, in the first direction, the battery cells 10 in the same column can be arranged with their large surfaces facing each other, and in the second direction, the battery cells 10 in the same row can be arranged with their small surfaces facing each other. The first direction can be the length direction, and the second direction can be the width direction. Of course, the small surfaces of the batteries can also be arranged with each other in the first direction, and the large surfaces of the batteries can be arranged with each other in the second direction. This application does not make any specific limitations.

[0081] The heating component 20 is arranged between two adjacent columns of battery cells 10. The heating component 20 includes a heating portion 202 extending along the second direction and a buffer portion 201. The heating portion 202 and the buffer portion 201 are stacked in the first direction. The heating portion 202 is suitable for heating the battery cells 10 and the buffer portion 201. The buffer portion 201 is suitable for shrinking under pressure and expanding under heat to deform flexibly, and to make the heating component 20 fit the battery cells 10.

[0082] The heating portion 202 and the buffer portion 201 of the heating assembly 20 extend along the second direction and are located between two adjacent columns of battery cells 10 in the first direction. They are suitable for heating the two columns of battery cells 10 on their large or small surfaces.

[0083] The heating part 202 and the buffer part 201 can be stacked in the first direction. The heating part 202 and the buffer part 201 can be both one and stacked in the first direction. Alternatively, there can be multiple heating parts 202 and multiple buffer parts 201, and multiple heating parts 202 and multiple buffer parts 201 can be stacked in the first direction, such as: the heating component 20 includes one heating part 202 and two buffer parts 201, and the heating part 202 is located on both sides of the buffer part 201, or the heating component 20 includes two buffer parts 201 and one heating part 202, and the buffer parts 201 are located on both sides of the heating part 202.

[0084] The buffer portion 201 can be made of a flexible material or a flexible film 22a can be selected to cover a liquid substance or a gaseous substance to achieve flexible deformation, and the heating portion 202 can be constructed as an electric heating structure such as a resistor, and the flexible deformation of the buffer portion 201 can include shape recovery under the action of elastic potential energy, shape recovery under the action of gravitational potential energy, etc., so that when the battery cell 10 is deformed, such as: when the battery cell 10 expands or contracts, the surface of the battery cell 10 opposite to the heating component 20 will bulge, and at least a portion of the buffer portion 201 can be compressed and contracted to fit with the bulging portion, and other portions of the buffer portion 201 can fit with the non-bulging portion, or the battery cell 10 and at least a portion of the heating component 20 can be separated, and as the temperature of the heating portion 202 rises, at least a portion of the buffer portion 201 can be heated and expanded to fill the battery cell 10. The gap between the battery cell 10 and the heating component 20 can make the fit between the battery cell 10 and the heating component 20 better, and the thermal conduction interface area between the battery cell 10 and the heating component 20 can be larger, and the area of ​​the thermal conduction interface can be kept stable, so that the heating efficiency and heating effect are better.

[0085] According to the battery pack 100 of the embodiment of the present application, the heating component 20 includes a heating part 202 and a buffer part 201. The buffer part 201 and the battery cell 10 can be heated by the heating part 202, and the buffer part 201 can produce flexible deformation, which can not only make the battery cell 10 and the heating component 20 fit better, thereby reducing the probability of dry burning of the heating component 20, improving the safety and reliability of the battery pack 100, and reducing safety hazards, but also when the battery cell 10 is deformed, the area of ​​the heat conduction interface between the heating component 20 and the battery cell 10 can be kept stable, which can further improve the heating effect and heating efficiency of the heating component 20.

[0086] The flexible deformation of the buffer portion 201 of the embodiment of the present application needs to at least achieve compression contraction and thermal expansion, and correspondingly, it can be achieved by combining compression contraction with elastic potential energy recovery, or by combining compression contraction with gravitational potential energy recovery, or by combining compression contraction with thermal expansion, or by combining compression contraction, gravitational potential energy recovery, and thermal expansion. The following three specific examples will specifically illustrate several feasible implementation plans of the embodiment of the present application. It should be understood that the exemplary description of the present application is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present application, and is not an exhaustive list.

[0087] First embodiment:

[0088] As shown in Figures 3 and 4, in the first embodiment, the heating component 20 includes: a substrate 21a and a flexible membrane 22a located on both sides of the substrate 21a, the flexible membrane 22a is sealed to the substrate 21a, a buffering heat-conducting medium is filled between the substrate 21a and the flexible membrane 22a, the buffering heat-conducting medium and the flexible membrane 22a define a buffer portion 201, and a heating element 211a is embedded in the substrate 21a to define a heating portion 202.

[0089] The peripheral edge of the flexible membrane 22a is sealed and connected to the substrate 21a to define a flexible space on at least one side surface of the flexible membrane 22a and the substrate 21a in the first direction, and the flexible space can be filled with a buffer heat-conducting medium. The flexible membrane 22a is flexible and can be deformed after being compressed. The buffer heat-conducting medium is a liquid medium, such as a coolant. As the flexible membrane 22a deforms, the buffer heat-conducting medium can flow to adapt to the deformation of the battery cell 10. After the battery cell 10 is deformed, the flexible membrane 22a deforms to make the flexible space flexible. The flexible membrane 22a is always in contact with the battery cell 10. A portion of the heat exchange surface of the battery cell 10 can achieve indirect heat exchange with the heating part 202 through the gas in the flexible membrane 22a, while the other portion can achieve indirect heat exchange with the heating part 202 through the buffer heat-conducting medium. After the flexible membrane 22a is deformed, the liquid level of the corresponding buffer heat-conducting medium gradually rises, the area of ​​the gas indirect heat exchange portion gradually decreases, and the heat exchange effect and heat exchange efficiency gradually increase. After heating is completed or stopped, the buffer heat-conducting medium can be restored to its initial state under the action of gravity.

[0090] During the continuous heating process of the buffer heat-conducting medium by the heating part 202, the proportion of the vaporized buffer heat-conducting medium gradually increases, and the proportion of the liquid buffer heat-conducting medium gradually decreases, causing the flexible membrane 22a to expand, which can further absorb the gap between the flexible membrane 22a and the battery cell 10, and can also increase the area of ​​the heat conduction interface between the heating component 20 and the battery cell 10, thereby improving the heat exchange effect and heat exchange efficiency.

[0091] In the first embodiment, flexible deformation is achieved by cooperating with the liquid buffer heat-conducting medium through the flexible membrane 22a, and the gravitational potential energy changes to achieve reset to the initial state. During the flexible deformation process, the liquid level (liquid surface height) of the liquid buffer heat-conducting medium changes, which can increase the heat conduction interface area and initially improve the heating effect and heating efficiency. As the heating time increases and the temperature in the working environment rises, the proportion of vaporized buffer heat-conducting medium gradually increases, and the proportion of liquid buffer heat-conducting medium gradually decreases, causing the flexible membrane 22a to expand, which can further fill the gap between the flexible membrane 22a and the battery cell 10, further increase the heat conduction interface area, and improve the fitting effect of the heat conduction interface, which can correspondingly further improve the heating effect and heating efficiency.

[0092] The flexible film 22a may be any one of PET (Polyethylene terephthalate) film, PI (Polyimide) film, PP (polypropylene) film, PC (Polycarbonate) film, and PVC (Polyvinylchlorid) film.

[0093] To facilitate assembly of the flexible film 22a structure between the battery cells 10, double-sided tape structures may be provided between the flexible film 22a and the substrate 21a, and between the flexible film 22a and the battery cells 10 during initial assembly, and may be removed after assembly is completed.

[0094] According to some embodiments of the present application, the buffering heat-conducting medium is configured as an insulating coolant.

[0095] The insulating coolant acts as a buffering heat-conducting medium. When the buffering heat-conducting medium in the heating component 20 leaks, it will not cause a short circuit in the surrounding components. This can further improve the safety and reliability of the battery pack 100 and reduce safety hazards. At the same time, the buffering heat-conducting medium also has a certain heat absorption capacity in non-cold environments. In some usage scenarios, it can also achieve auxiliary heat dissipation for the battery cell 10.

[0096] According to some embodiments of the present application, the heating portion 202 is configured as a positive temperature coefficient thermistor.

[0097] The heating part 202 can be embedded in the substrate 21a or wound around the substrate 21a. The higher the temperature of the heating part 202, the greater the resistance. When the temperature is too high, the resistance of the heating part 202 rises to a larger value. At this time, the heating part 202 is equivalent to a short circuit, which can achieve overheating protection to realize the overheating protection function and improve the safety and reliability of the heating component 20.

[0098] Second embodiment:

[0099] As shown in FIG5 and FIG6 , in the second embodiment, the heating assembly 20 includes a buffer layer 21 b and heating films 22 b located on both sides of the buffer layer 21 b . The buffer layer 21 b defines a buffer portion 201 , and the heating film 22 b defines a heating portion 202 .

[0100] The buffer layer 21b and the heating film 22b form a sandwich structure. In the first direction, the heating film 22b, the buffer layer 21b and the heating film 22b are stacked. In the first direction, the two heating films 22b are suitable for fitting with two adjacent battery cells 10 in the first direction, and the two battery cells 10 are heated by the two heating films 22b respectively, and the buffer layer 21b is located between the two heating films 22b. When the battery cell 10 expands, the buffer layer 21b can be compressed and contracted so that the heating film 22b can adapt to the deformation of the battery cell 10, reducing the probability of cracking of the heating film 22b after being subjected to force, and can keep the heating film 22b and the battery cell 10 still in contact. After heating is stopped, the buffer layer 21b can return to its original state under the action of elastic potential energy, so that the heat conduction interface area between the battery cell 10 and the heating film 22b remains stable, thereby improving the heating efficiency and heating effect.

[0101] According to some embodiments of the present application, the buffer layer 21b is constructed as a foam layer.

[0102] The foam layer can expand when heated. When the heating film 22b is dry-burned, the foam expands when heated to push the heating film 22b to fit the battery cell 10, improving the dry-burning phenomenon, improving the heating effect and heating efficiency, reducing safety hazards and improving reliability.

[0103] Third embodiment:

[0104] As shown in FIG7 and FIG8 , according to some embodiments of the present application, the buffer layer 21b includes: a first sub-buffer layer 211b and a second sub-buffer layer 212b located on both sides of the first sub-buffer layer 211b , and the first sub-buffer layer 211b and the second sub-buffer layer 212b are made of different materials.

[0105] In the third embodiment, based on the second embodiment, the buffer layer 21b is differentiated into a sandwich structure, and heating films 22b are further provided on both sides of the buffer layer 21b. The buffer layer 21b includes a first sub-buffer layer 211b and a second sub-buffer layer 212b located on both sides of the first sub-buffer layer 211b. The first sub-buffer layer 211b and the second sub-buffer layer 212b are made of different materials, so that one forms a heat-expanding structure and the other forms a pressure-deformed structure, or both can expand under heat and deform under pressure, but with different deformation coefficients and expansion coefficients.

[0106] The same technical effects as those of the first and second embodiments can also be achieved, and will not be described in detail here.

[0107] Exemplarily, the first sub-buffer layer 211b is configured as an airbag layer; and the second sub-buffer layer 212b is configured as a foam layer.

[0108] The heating film 22b can be located between adjacent battery cells 10 and be in an interference compression assembly. When the battery cell 10 is deformed, the foam and the airbag can be squeezed, and the airbag is deformed to make the heating film 22b fit stably with the battery cell 10. When the heating film 22b is dry-burned, the gas inside the airbag can expand due to the heat to push the heating film 22b toward the battery cell 10, thereby improving the heating effect and heating efficiency.

[0109] According to some embodiments of the present application, the airbag layer comprises a plurality of airbags, and the airbags are filled with a heated expansion medium.

[0110] The heat expansion medium may be an inert gas, so that the heat expansion medium drives the airbag to expand, absorbs the gap between the heating film 22b and the battery cell 10, and reduces the probability of dry burning of the heating film 22b.

[0111] As shown in FIG. 9 , FIG. 10 and FIG. 11 , according to some embodiments of the present application, the size of the heating assembly 20 in the first direction is 0.5 mm to 20 mm.

[0112] Exemplarily, the size of the heating component 20 in the first direction can be 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 15mm, 20mm, etc., so that the thickness of the heating component 20 is more reasonable, taking into account the expansion absorption capacity, heating capacity and bonding capacity of the heating component 20 (the ability to make the heating component 20 more bonded to the battery cell 10).

[0113] As shown in FIG9 , FIG10 and FIG11 , according to some embodiments of the present application, end plates 30 are further provided at both ends of each column of battery cells 10 in the second direction, and the ends of the buffer portion 201 in the second direction are connected to the end plates 30 via fasteners.

[0114] The fasteners can be rivets, screws, bolts, etc., and fixing the heating component 20 and the battery cell 10 with fasteners can improve the fixing stability and reliability between the heating component 20 and the battery cell 10, and there is no need to set double-sided tape. The connection stability of the heating component 20 is less affected by aging and has higher stability.

[0115] As shown in FIG. 12 and FIG. 13 , according to some embodiments of the present application, the heating assembly 20 further includes: a connecting plate 203 , which extends along the first direction, and the ends of the adjacent buffer portions 201 in the first direction are connected by the connecting plate 203 .

[0116] The heating assembly 20 may include a plurality of heating units, each of which is disposed between two columns of battery cells 10 , and the plurality of heating units may be connected via a connecting plate 203 , so that the heating assembly 20 may be arranged in a serpentine shape.

[0117] When there are multiple columns of battery cells 10 in the battery pack 100 or the battery module 600, a column of heating units is set between adjacent columns of battery cells 10, and the multiple columns of heating units are all connected to the connecting plate 203, which can reduce the difficulty of arranging the heating component 20 and improve the convenience of arranging the heating component 20. The connecting plate 203 can also be fixed to the end plate 30, further improving the fixing stability and reliability of the heating component 20.

[0118] The present application provides an energy storage system, including: the battery pack 100 in the above embodiment.

[0119] As shown in FIG. 1 and FIG. 3 , the present application provides an electric device 200 , including: the battery pack 100 in the above embodiment.

[0120] According to the battery pack 100 of the embodiment of the present application, a heating assembly 20 can be arranged between adjacent columns of battery cells 10, and the buffer portion 201 is suitable for buffering and absorbing the expansion of the battery cells 10 or reducing the gap between the battery cells 10 and the heating assembly 20 due to expansion, so that the area of ​​the heat conduction interface can be kept stable or the area of ​​the heat conduction interface can be increased to improve the heating efficiency and heating effect.

[0121] The heating component 20 of the embodiment of the present application can be constructed as a structure that restores the initial state by gravitational potential energy in conjunction with the thermal expansion of the liquid medium, or it can be an elastic potential energy restoration initial assembly in conjunction with the thermal expansion structure to achieve the above technical effects.

[0122] As shown in Figures 9, 10, 11 and 13, in the first embodiment, the number of the heating part 202 and the buffer part 201 of the heating component 20 can be multiple and divided into multiple heating units, each heating unit is located between two adjacent columns of battery cells 10, and the multiple heating parts 202 and buffer parts 201 in each heating unit can be arranged at intervals and connected by a plate body (such as a substrate) connected to the connecting plate 203, so that the entire heating component 20 is strip-shaped; in the second embodiment, the buffer part 201 is defined by a foam layer extending along the second direction, and the foam layer serves as a supporting structure for the heating part 202. The heating part 202 is constructed as a heating film, which is supported by the foam layer, and rigid structures can be provided at both ends of the foam layer, and connected to the end plate through the rigid structure. The rigid structures at both ends of the foam layer are connected to the connecting plate 203 so that the entire heating component 20 can be in the shape of a strip; in the third embodiment, the buffer portion 201 is defined by the foam layer extending along the second direction and the airbag layer located on the inner side of the foam layer, the foam layer serves as a supporting structure for the heating portion 202, and the airbag layer supports the airbag layer on the inner side of the foam layer. The heating portion 202 is constructed as a heating film, which is supported by the foam layer, and rigid structures can be provided at both ends of the foam layer and connected to the end plate through the rigid structure. The rigid structures at both ends of the foam layer are connected to the connecting plate 203 so that the entire heating component 20 can be in the shape of a strip, and there can be multiple airbags in the airbag layer, and the multiple airbags are constructed as strip airbags and extend along the second direction, or are constructed as multiple spherical airbags, which are arranged in sequence in the second direction.

[0123] Other structures and operations of the battery pack 100, energy storage system and power-consuming device 200 according to the embodiment of the present application are well known to those skilled in the art and will not be described in detail here.

[0124] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0125] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery pack, wherein: include: A battery cell (10), wherein the battery cell (10) is multiple, and the multiple battery cells (10) are arranged in columns along a first direction and in rows along a second direction, and the first direction is orthogonal to the second direction; A heating assembly (20) is provided between two adjacent rows of battery cells (10). The heating assembly (20) comprises a heating portion (202) and a buffer portion (201) extending along the second direction. The heating portion (202) and the buffer portion (201) are stacked in the first direction. The heating portion (202) is suitable for heating the battery cells (10) and the buffer portion (201). The buffer portion (201) is suitable for shrinking under pressure and expanding under heat to deform flexibly, so that the heating assembly (20) and the battery cells (10) are attached to each other.

2. The battery pack according to claim 1, wherein: The heating assembly (20) comprises: a substrate (21a) and flexible membranes (22a) located on both sides of the substrate (21a); the flexible membranes (22a) are sealed to the substrate (21a); a buffering heat-conducting medium is filled between the substrate (21a) and the flexible membrane (22a); the buffering heat-conducting medium and the flexible membrane (22a) define the buffer portion (201); and a heating element (211a) is embedded in the substrate (21a) to define the heating portion (202).

3. The battery pack according to claim 2, wherein: The buffer heat-conducting medium is configured as an insulating coolant.

4. The battery pack according to claim 2, wherein: The heating portion (202) is configured as a positive temperature coefficient thermistor.

5. The battery pack according to claim 1, wherein: The heating component (20) comprises a buffer layer (21b) and heating films (22b) located on both sides of the buffer layer (21b), the buffer layer (21b) defines the buffer portion (201), and the heating film (22b) defines the heating portion (202).

6. The battery pack according to claim 5, wherein: The buffer layer (21b) is constructed as a foam layer.

7. The battery pack according to claim 5, wherein: The buffer layer (21b) comprises: a first sub-buffer layer (211b) and a second sub-buffer layer (212b) located on both sides of the first sub-buffer layer (211b); the first sub-buffer layer (211b) and the second sub-buffer layer (212b) are made of different materials.

8. The battery pack according to claim 7, wherein: The first sub-buffer layer (211b) is constructed as an airbag layer.

9. The battery pack according to claim 7, wherein: The second sub-buffer layer (212b) is constructed as a foam layer.

10. The battery pack according to claim 8, wherein: The airbag layer has a plurality of airbags therein, and the airbags are filled with a heat-expandable medium.

11. The battery pack according to any one of claims 1 to 10, wherein: The size of the heating component (20) in the first direction is 0.5 mm to 20 mm.

12. The battery pack according to any one of claims 1 to 10, wherein: End plates (30) are further provided at both ends of each column of battery cells (10) in the second direction, and the ends of the buffer portion (201) in the second direction are connected to the end plates (30) via fasteners.

13. The battery pack according to claim 12, wherein: The heating assembly (20) further comprises a connecting plate (203), wherein the connecting plate (203) extends along the first direction, and ends of the buffer portions (201) adjacent to each other in the first direction are connected via the connecting plate (203).

14. An energy storage system, wherein: include: The battery pack according to any one of claims 1 to 13.

15. An electrical device (200), wherein: include: The battery pack according to any one of claims 1 to 13.

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