Battery device, energy storage device and energy storage system

Abstract

Some embodiments of the utility model provide a battery device, an energy storage device and an energy storage system, the battery device comprises a box body and a battery monomer, the box body forms a cavity, the battery monomer is accommodated in the cavity, the box body comprises a first wall part, at least part of the first wall part is provided with an expansion structure, and the expansion structure separates the cavity from the outside; the softening point A of the expansion structure is set to be larger than or equal to 90 DEG C and smaller than or equal to 120 DEG C. At least part of the first wall part in the box body is provided with the expansion structure for separating the cavity from the outside, the softening point of the expansion structure is set to be A, and the A is greater than or equal to 90 DEG C and less than or equal to 120 DEG C, so that the temperature and the pressure in the cavity are increased due to discharged substances of the battery monomers, and the expansion structure becomes soft; and the first wall part is expanded outwards under the action of pressure in the cavity, so that not only is the heat dissipation area of the box body increased, but also the rise of the pressure in the cavity is reduced, the battery device can be quickly decompressed and cooled, and the reliability of the battery device is facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage devices, and in particular to a battery device, an energy storage device and an energy storage system. Background Art

[0002] Battery devices have the advantages of high specific energy and high power density. They are widely used in energy storage devices such as energy storage containers or energy storage cabinets. Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems.

[0003] As the application fields of battery devices continue to increase, how to improve the reliability of battery devices has attracted more and more attention. Therefore, how to quickly reduce the pressure and temperature of thermal runaway battery devices to ensure the reliability of battery devices has attracted more and more attention from technicians in this field. Utility Model Content

[0004] In view of the above problems, the present application provides a battery device, an energy storage device and an energy storage system. The battery device can quickly reduce pressure and temperature when thermal runaway occurs and has good reliability.

[0005] In a first aspect, some embodiments of the present application provide a battery device, comprising a case and a battery cell, wherein the case forms a cavity, and the battery cell is accommodated in the cavity, and the case comprises a first wall portion, and at least a portion of the first wall portion is provided with an expansion structure, and the expansion structure separates the cavity from the outside; the softening point of the expansion structure is set to A, 90°C≤A≤120°C, and the expansion structure can be deformed after softening to expand the cavity.

[0006] In the above structure, since at least part of the first wall portion in the box body is provided with an expansion structure that separates the cavity from the outside, and the softening point of the expansion structure is set to A, 90°C≤A≤120°C, when a battery cell in the battery device undergoes thermal runaway, the discharge of substances from the battery cell causes the temperature and pressure in the cavity to rise, which softens the expansion structure and deforms under the action of the pressure in the cavity, causing the first wall portion to bulge outward, which not only increases the heat dissipation area of ​​the box body, but also reduces the increase in pressure in the cavity, so that the battery device can quickly reduce pressure and cool down, which is beneficial to the reliability of the battery device.

[0007] According to the battery device provided in some embodiments of the present application, the linear expansion coefficient of the expansion structure is set to B, B≥70×10 -6 m / mK, so that the expansion structure can expand after being heated, which can alleviate the thinning of the expansion structure caused by bulging, so that the volume of the cavity can be fully expanded, which is beneficial to the deformation of the expansion structure and can also reduce the possibility of rupture of the expansion structure due to deformation.

[0008] According to the battery device provided in some embodiments of the present application, the first wall portion is provided with a through hole which penetrates along the thickness direction thereof, and the expansion structure is located in the through hole and sealingly connected to the inner wall surface of the through hole, so that the expansion structure can seal and block the through hole, thereby reducing the possibility of leakage of the discharged material in the cavity to the outside, which is beneficial for the box body to form a sealed space in the cavity.

[0009] According to the battery device provided in some embodiments of the present application, the inner wall surface of the through hole is provided with an inwardly recessed recess, and the outer peripheral surface of the expansion structure is convexly provided with a protrusion, which is inserted into the recess, and can increase the contact area between the expansion structure and the inner wall surface of the through hole, which is conducive to enabling the expansion structure to be more firmly set in the through hole.

[0010] According to the battery device provided in some embodiments of the present application, the expansion structure is bonded to the inner wall surface of the through hole by an adhesive, and the softening point of the adhesive is set to C, C>A, so that the adhesive has a higher softening temperature than the expansion structure, so that when the expansion structure softens and deforms, the adhesive is not easy to soften and still has good bonding ability, so that the expansion structure can be firmly bonded to the inner wall surface of the through hole.

[0011] According to the battery device provided in some embodiments of the present application, the first wall portion includes a first part and a second part that are interconnected, the first part is configured as an expansion structure, and the first part and the second part are an integrally molded structure, so that the first part and the second part are an integral structure, which is not only beneficial to improving the structural strength of the first wall portion, but also beneficial to improving the sealing of the first wall portion.

[0012] According to the battery device provided in some embodiments of the present application, the box body further includes a second wall portion connected to the first wall portion, and the battery device further includes a pressure relief mechanism, which is arranged on the second wall portion to connect the cavity with the outside. By arranging the pressure relief mechanism on the second wall portion, the pressure relief mechanism on the second wall portion is not easily affected when the first wall portion is deformed, which is conducive to keeping the pressure relief mechanism in a normal working state.

[0013] According to the battery device provided in some embodiments of the present application, the expansion structure is an ethylene-vinyl acetate copolymer structure.

[0014] In a second aspect, some embodiments of the present application provide an energy storage device, which includes a cabinet and at least one battery device as provided in any of the above technical solutions; the cabinet is formed with a accommodating space, and the battery device is accommodated in the accommodating space. The first wall portion of the battery device is arranged toward the wall of the cabinet, and the expansion structure can contact the wall of the cabinet, so that the heat of the battery device can be transferred to the wall of the cabinet by heat conduction, which is beneficial to increase the speed at which the heat of the battery device diffuses outward.

[0015] According to the energy storage device provided in some embodiments of the present application, the energy storage device also includes an electrical module and a fire protection module, both of which are arranged in the accommodating space, and the electrical module is electrically connected to the battery device.

[0016] According to the energy storage device provided in some embodiments of the present application, at least one battery cluster is disposed in the accommodating space, and the battery cluster includes at least two battery devices.

[0017] In a third aspect, some embodiments of the present application provide an energy storage system, which includes a power conversion device and at least one energy storage device as provided by any of the above technical solutions, and the power conversion device is used to electrically connect a power generation device and at least one energy storage device.

[0018] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0019] Some embodiments of the present application provide a battery device, which includes a box and a battery cell, wherein the box is formed with a cavity, the battery cell is accommodated in the cavity, the box includes a first wall, at least part of the first wall is provided with an expansion structure, the expansion structure separates the cavity from the outside; the softening point of the expansion structure is set to A, 90℃≤A≤120℃, and the expansion structure can be deformed to expand the cavity after softening. In the above structure, since at least part of the first wall in the box is provided with an expansion structure that separates the cavity from the outside, and the softening point of the expansion structure is set to A, 90℃≤A≤120℃, when the battery cell in the battery device has thermal runaway, the discharge of the battery cell causes the temperature and pressure in the cavity to rise, which makes the expansion structure soften, and deforms under the action of the pressure in the cavity, so that the first wall bulges outward, which not only increases the heat dissipation area of ​​the box, but also reduces the increase in pressure in the cavity, so that the battery device can quickly reduce pressure and temperature, which is beneficial to the reliability of the battery device.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0022] Figure 1 An exploded view of a battery device provided in some embodiments of the present application;

[0023] Figure 2 A disassembled diagram of a battery device provided in some other embodiments of the present application;

[0024] Figure 3 for Figure 1 The partial schematic diagram of the F in the middle;

[0025] Figure 4 A left view of an expansion structure provided in some embodiments of the present application;

[0026] Figure 5 A schematic diagram of the internal structure of an energy storage device provided in some embodiments of the present application;

[0027] Figure 6 A schematic diagram of the internal structure of a partial battery device of an energy storage device provided in some embodiments of the present application when thermal runaway occurs.

[0028] In the accompanying drawings: 1, box body; 11, first wall; 111, through hole; 1111, recess; 112, first part; 113, second part; 12, expansion structure; 121, protrusion; 13, second wall; 131, pressure relief mechanism; 14, battery cell; 15, cavity; 10, cabinet; 20, battery device; 30, accommodating space; 40, electrical module; 50, fire protection module; 60, battery cluster. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0031] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0035] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-9°, the two directions can be considered to be perpendicular; if the angle between two directions is 5°-5°, the two directions can be considered to be parallel.

[0036] The term “plurality” used in this application refers to two or more (including two).

[0037] At present, from the perspective of market development, the application of battery devices is becoming more and more extensive. Battery devices are not only used in energy storage power supply systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in energy storage devices such as energy storage containers or energy storage cabinets. With the continuous expansion of the application field of battery devices, people's requirements for the reliability of battery devices are also constantly increasing.

[0038] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar component.

[0039] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0040] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0041] In some embodiments, the battery device may include one or more battery packs, which may include one or more battery cell assemblies. As an example, the battery pack includes a box and one or more battery cell assemblies, which are, for example, accommodated in the box in a fixed manner. As another example, the battery device includes multiple battery packs, which may be connected in series, in parallel, or in a mixed manner.

[0042] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate, and the first box can enclose a cavity with an opening, and the first box covers the opening.

[0043] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0044] In some embodiments, the multiple battery packs included in the battery device may constitute one or more battery clusters, so that the energy storage device provided in the embodiment of the present application includes one or more battery clusters to increase the voltage and capacity of the energy storage device. The battery cluster may include multiple battery packs, and the multiple battery packs are connected in series through a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters may be connected in series, in parallel, or in a mixed connection.

[0045] The energy storage device can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems. The energy storage device can store electrical energy as needed and output electrical energy at an appropriate time. For example, the energy storage device can store electrical energy during low power consumption and provide electrical energy to relevant users or electrical equipment during peak power consumption. The energy storage system provided in the embodiment of the present application can be any power system that requires the use of an energy storage device.

[0046] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0047] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters, wherein the battery clusters are housed in the cabinet.

[0048] In some embodiments, the energy storage device may include modules such as a thermal management module, a main control module, a master control module, a power distribution module, and a fire protection module.

[0049] As an example, the thermal management module may include a liquid cooling unit that provides cooling liquid for regulating the temperature of the battery cells to each battery device through a pipeline.

[0050] As an example, the main control module can be used as a battery management unit of a battery cluster to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power or temperature of the battery cluster. For example, the charging and discharging current and voltage of the battery cluster can be controlled. The main control module includes modules such as the slave battery management unit SBMU (SBMU) and the fusion switch.

[0051] As an example, the master control module can be used as a battery management unit of an energy storage device to monitor and manage the energy storage device. The master control module can monitor information such as the current, voltage, power, state of charge or temperature of the energy storage device. For example, the charging and discharging current, voltage, etc. of the energy storage device can be controlled. As an example, the master control module includes an insulation monitoring module IMM (Insulation Monitoring Module, abbreviated as IMM), a master battery management unit MBMU (Master Battery Management Unit, MBMU), Ethernet ETH (EtherNet, ETH) and a fiber optic conversion module.

[0052] As an example, the fire protection module includes a control panel, a detector, an alarm device, etc., which are used to detect, alarm or extinguish fire in the energy storage system.

[0053] As an example, the power distribution module can be used to distribute power to the power consumption modules of the energy storage device.

[0054] Current energy storage devices usually have a large capacity and can output or store electrical energy with a large amount of electricity continuously, which makes the battery cells inside them often work under a large load state, which makes people pay special attention to the reliability of the battery devices in the energy storage devices. Although the battery devices in the prior art are equipped with a pressure relief mechanism, there is a risk that the smoke and electrolyte droplets released after the thermal runaway of the battery cells will not enter the pressure relief mechanism but accumulate inside the battery device, which is not conducive to the heat dissipation and pressure control of the battery device, and brings challenges to the reliability of the battery device.

[0055] In order to enable the battery device to quickly reduce pressure and cool down when thermal runaway occurs, and to improve the reliability of the battery device, some embodiments of the present application provide a battery device, which includes a box and a battery cell, the box is formed with a cavity, the battery cell is accommodated in the cavity, the box includes a first wall, at least part of the first wall is provided with an expansion structure, the expansion structure separates the cavity from the outside; the softening point of the expansion structure is set to A, 90℃≤A≤120℃, and the expansion structure can be deformed to expand the cavity after softening. In the above structure, since at least part of the first wall in the box is provided with an expansion structure that separates the cavity from the outside, and the softening point of the expansion structure is set to A, 90℃≤A≤120℃, when the battery cell in the battery device has thermal runaway, the discharge of the battery cell causes the temperature and pressure in the cavity to rise, which makes the expansion structure soften, and deforms under the action of the pressure in the cavity, so that the first wall bulges outward, which not only increases the heat dissipation area of ​​the box, but also reduces the increase in pressure in the cavity, so that the battery device can quickly reduce pressure and cool down, which is beneficial to the reliability of the battery device.

[0056] The battery device described in the embodiments of the present application is suitable for an energy storage device using the battery device.

[0057] The energy storage device described in the embodiment of the present application may be an energy storage container or an energy storage cabinet, and the energy storage device described in the embodiment of the present application may be applicable to an energy storage system, which may include one or more energy storage devices and a power conversion device (Power Converter System, PCS for short), the power conversion device being used to connect between the power generation equipment and the energy storage device. The power generation equipment is used to generate electrical energy, and the electrical energy generated by the power generation equipment may be stored in the energy storage device through the power conversion device. As an example, the power generation equipment may specifically be a solar panel, a hydroelectric power generation equipment, a thermal power generation equipment, a wind power generation equipment, and the like.

[0058] Some embodiments of the present application provide a battery device, such as Figure 1 and Figure 2As shown, the battery device 20 includes a battery cell 14 and a box body 1, the box body 1 forms a cavity 15, the battery cell 14 is accommodated in the cavity 15, the box body 1 includes a first wall portion 11, at least part of the first wall portion 11 is provided with an expansion structure 12, the expansion structure 12 separates the cavity 15 from the outside; the softening point of the expansion structure 12 is set to A, 90℃≤A≤120℃, and the expansion structure 12 can be deformed after softening to expand the cavity 15.

[0059] The battery cell 14 may be the smallest unit that can output electric energy as an independent power source. The box 1 may be a component for enclosing a cavity 15, and the battery cell 14 is disposed in the cavity 15 in the box 1. The box 1 may be the first box 1 described in the above technical solution, or the second box 1 described in the above technical solution. The battery device 20 may be provided with a plurality of battery cells 14, and the plurality of battery cells 14 may be connected in series, in parallel, or in mixed connection to form a whole contained in the cavity 15 of the box 1.

[0060] The first wall portion 11 may be a partial wall structure in the box body 1, which is used to form the cavity 15. For example, the first wall portion 11 may be a wall structure in the first box body 1 in the aforementioned technical solution, or may be a wall structure in the second box body 1, and those skilled in the art may set it according to actual conditions.

[0061] The box 1 may include a first box 1 and a second box 1. The first box 1 and the second box 1 are buckled together to form a closed space inside the box 1 to accommodate the battery cell 14 assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box 1 can be a top cover or a bottom plate, and the first box 1 can enclose a cavity 15 with an opening, and the first box 1 covers the opening.

[0062] The expansion structure 12 may be a structure disposed on the first wall portion 11 that can be deformed after softening, which can separate the cavity 15 from the outside and is used to achieve outward expansion of the volume of the cavity 15. At least part of the first wall portion 11 is provided with the expansion structure 12, which may mean that the entire first wall portion 11 serves as the expansion structure 12, so that the entire first wall portion 11 can soften and deform to achieve expansion of the volume of the cavity 15; or it may mean that a part of the structure in the first wall portion 11 serves as the expansion structure 12, so that a part of the first wall portion 11 can soften and deform to achieve expansion of the volume of the cavity 15. After the expansion structure 12 expands, the surface area of ​​the box body 1 will be increased, which can not only increase the heat dissipation area of ​​the box body 1, but also reduce the increase in pressure in the cavity 15.

[0063] The softening point may be a temperature at which the expansion structure 12 softens and can deform. By setting the softening point A of the expansion structure 12 to a range of 90°C≤A≤120°C, not only can the expansion structure 12 be softened in time when thermal runaway occurs in the battery device 20, facilitating the outward expansion of the first wall portion 11, but also the expansion structure 12 is not easily softened due to the temperature rise caused by the heat of the battery device 20, thereby reducing the possibility of failure of the expansion structure 12.

[0064] In the above structure, since at least part of the first wall portion 11 in the box body 1 is provided with an expansion structure 12 that separates the cavity 15 from the outside, and the softening point of the expansion structure 12 is set to A, 90°C≤A≤120°C, when the battery cell 14 in the battery device 20 undergoes thermal runaway, the discharged substances of the battery cell 14 cause the temperature and pressure in the cavity 15 to rise, which makes the expansion structure 12 soften and deform under the action of the pressure in the cavity 15 so that the first wall portion 11 bulges outward, which not only increases the heat dissipation area of ​​the box body 1, but also reduces the increase in pressure in the cavity 15, so that the battery device 20 can quickly reduce pressure and temperature, which is beneficial to the reliability of the battery device 20.

[0065] In some embodiments, the linear expansion coefficient of the expansion structure 12 is set to B, B ≥ 70 × 10 -6 m / mK.

[0066] By setting the linear expansion coefficient B of the expansion structure 12 to a range of B ≥ 70 × 10 -6 m / mK, so that the expansion structure 12 can expand after being heated, which can alleviate the thinning of the expansion structure 12 caused by bulging, so that the volume of the cavity 15 can be fully expanded, which is beneficial to the deformation of the expansion structure 12 and can also reduce the possibility of rupture of the expansion structure 12 due to deformation.

[0067] In some embodiments, reference Figure 3 The first wall portion 11 is provided with a through hole 111 penetrating along the thickness direction thereof, and the expansion structure 12 is located in the through hole 111 and is sealed and connected to the inner wall surface of the through hole 111 .

[0068] The through hole 111 may be a hole-shaped structure provided on the first wall portion 11, which penetrates the first wall portion 11 along the thickness direction of the first wall portion 11. By providing the expansion structure 12 in the through hole 111, the expansion structure 12 can separate the cavity 15 from the outside, so that when the pressure in the cavity 15 increases, the expansion structure 12 can deform and move outward to expand the volume of the cavity 15.

[0069] By sealingly connecting the expansion structure 12 to the inner wall surface of the through hole 111, the expansion structure 12 can seal the through hole 111, reducing the possibility of leakage of the discharged material in the cavity 15 to the outside, which is beneficial for the box 1 to form a sealed space in the cavity 15.

[0070] In some embodiments, reference Figure 3 The inner wall surface of the through hole 111 is provided with a recessed portion 1111 recessed inwardly, referring to Figure 4 A protrusion 121 is convexly provided on the outer peripheral surface of the expansion structure 12 , and the protrusion 121 is inserted into the recess 1111 .

[0071] The recess 1111 may be a recessed structure formed by the inner wall of the through hole 111 being recessed inward. The protrusion 121 may be a protruding structure protruding outward from the outer peripheral surface of the expansion structure 12. By providing the recess 1111 on the inner wall surface of the through hole 111, providing the protrusion on the outer peripheral surface of the expansion structure 12, and inserting the protrusion 121 into the recess 1111, the contact area between the expansion structure 12 and the inner wall surface of the through hole 111 can be increased, which is conducive to making the expansion structure 12 more firmly arranged in the through hole 111.

[0072] In some embodiments, the expansion structure 12 is bonded to the inner wall surface of the through hole 111 by adhesive, and the softening point of the adhesive is set to C, C>A.

[0073] The expansion structure 12 is bonded to the inner wall of the through hole 111 by adhesive, and the outer peripheral surface of the expansion structure 12 and the inner wall of the through hole 111 are bonded by adhesive. The expansion structure 12 is bonded to the inner wall of the through hole 111 by adhesive, which not only allows the expansion structure 12 to be conveniently connected to the through hole 111, but also improves the sealing between the outer peripheral surface of the expansion structure 12 and the inner wall of the through hole 111.

[0074] By setting the softening point C of the adhesive to C>A, the adhesive has a higher softening temperature than the expansion structure 12, so that when the expansion structure 12 softens and deforms, the adhesive is not easy to soften and still has good bonding ability, so that the expansion structure 12 can be firmly bonded to the inner wall surface of the through hole 111.

[0075] In some embodiments, the first wall portion 11 includes a first portion 112 and a second portion 113 connected to each other, the first portion 112 is configured as an expansion structure 12, and the first portion 112 and the second portion 113 are an integrally formed structure.

[0076] The first part 112 and the second part 113 are two interconnected parts in the first wall portion 11. By configuring the first part 112 as the expansion structure 12, a part of the structure in the first wall portion 11 is the expansion structure 12, so that the first wall portion 11 expands the volume of the cavity 15 through deformation of the part of the structure.

[0077] The first part 112 and the second part 113 are an integrally formed structure, which may mean that the first part 112 and the second part 113 are made by an integrally formed process, so that the first part 112 and the second part 113 are an integral structure, which is not only beneficial to improving the structural strength of the first wall portion 11, but also beneficial to improving the sealing performance of the first wall portion 11.

[0078] In some embodiments, the box body 1 further includes a second wall portion 13 connected to the first wall portion 11 , and the battery device 20 further includes a pressure relief mechanism 131 , which is disposed on the second wall portion 13 to connect the cavity 15 with the outside.

[0079] The second wall portion 13 may be a partial wall structure in the box body 1, which is connected to the first wall portion 11 to form a cavity 15. Exemplarily, the second wall portion 13 may enclose a cavity 15 having an opening at one end, and the first wall portion 11 covers the opening, so that the box body 1 forms the cavity 15; or the first wall portion 11 may enclose a first cavity 15 having a first opening at one end, and the second wall portion 13 may enclose a second cavity 15 having a second opening at one end, and the second opening of the second wall portion 13 may be buckled with the first opening of the first wall portion 11, and the first cavity 15 and the second cavity 15 form the cavity 15.

[0080] The pressure relief mechanism 131 may be a mechanism provided on the housing 1 for releasing the internal pressure of the cavity 15, and is used to connect the cavity 15 with the outside. The pressure relief mechanism 131 may be a one-way valve, a balancing valve, etc. When the internal pressure of the cavity 15 reaches or exceeds a preset value, the pressure relief mechanism 131 can reduce the internal pressure of the cavity 15 by releasing the discharged substances inside the cavity 15 to the outside.

[0081] By arranging the pressure relief mechanism 131 on the second wall portion 13 , the pressure relief mechanism 131 on the second wall portion 13 is not easily affected when the first wall portion 11 is deformed, which is conducive to keeping the pressure relief mechanism 131 in a normal working state.

[0082] In some embodiments, the intumescent structure 12 is an ethylene vinyl acetate structure.

[0083] The expansion structure 12 is an ethylene-vinyl acetate copolymer structure, which may mean that the expansion structure 12 is made of ethylene-vinyl acetate copolymer. This allows the expansion structure 12 to change from a glass state with performance close to that of plastic to a high elastic state close to that of rubber after the temperature rises from low to high to the softening point. This allows the expansion structure 12 to have strong structural strength to maintain the structural strength of the first wall portion 11 when the temperature is lower than the softening point. When the temperature reaches the softening point, the expansion structure 12 can deform under the pressure inside the cavity 15.

[0084] Exemplarily, the expansion structure 12 may also be made of a high molecular polymer material having the same softening point as ethylene-vinyl acetate copolymer.

[0085] In the technical solution provided in the present application, when a battery cell 14 in a battery device 20 undergoes thermal runaway, if the released substances such as smoke and electrolyte droplets after the thermal runaway cannot be discharged to the outside through the pressure relief mechanism 131, resulting in an increase in the rated pressure and temperature inside the battery device 20, after the temperature of the expansion structure 12 reaches the softening point, the expansion structure 12 becomes soft and deforms under the action of the pressure in the cavity 15, causing the first wall portion 11 to bulge outward, which not only increases the heat dissipation area of ​​the box body 1, but also reduces the increase in pressure in the cavity 15, so that the battery device 20 can quickly reduce pressure and cool down.

[0086] Some embodiments of the present application also provide an energy storage device, referring to Figure 5 and Figure 6 The energy storage device includes a cabinet 10 and at least one battery device 20 as provided in the above technical solution; the cabinet 10 is formed with a accommodating space 30, the battery device 20 is accommodated in the accommodating space 30, the first wall portion 11 of the battery device 20 is arranged toward the wall of the cabinet 10, and the expansion structure 12 can contact the wall of the cabinet 10.

[0087] The accommodating space 30 formed by the cabinet 10 is used to accommodate components such as the battery device 20 , so that the components such as the battery device 20 in the energy storage device can be protected by the cabinet 10 .

[0088] By arranging the first wall portion 11 of the battery device 20 toward the wall of the cabinet 10, the expansion structure 12 is deformed to increase the volume of the cavity 15, so that the expansion structure 12 can contact the wall of the cabinet 10 (such as Figure 6 As shown), the heat of the battery device 20 can be transferred to the wall of the cabinet 10 by heat conduction, which is beneficial to increase the speed of heat diffusion of the battery device 20.

[0089] In some embodiments, the energy storage device further includes an electrical module 40 and a fire protection module 50 . Both the electrical module 40 and the fire protection module 50 are disposed in the accommodating space 30 , and the electrical module 40 is electrically connected to the battery device 20 .

[0090] Exemplarily, the fire module 50 may include a fire control box and a fire sprinkler, which is disposed in the accommodating space 30 and electrically connected to the fire control box. The fire control box can control the operation of the fire sprinkler when thermal runaway occurs in the battery device 20 in the accommodating space 30.

[0091] The electrical module 40 may include electrical components such as a high-voltage box and a distribution box. The electrical module 40 is electrically connected to the battery device 20 so that the energy storage device can be charged and discharged.

[0092] In some embodiments, at least one battery cluster 60 is disposed in the accommodation space 30 , and the battery cluster 60 includes at least two battery cells 14 .

[0093] The battery cluster 60 may be a device including at least two battery devices 20, which may be provided with a structure such as a bracket to support or place the battery device 20. The battery cluster 60 can reasonably arrange at least two battery devices 20 so that the battery devices 20 reasonably utilize the space in the accommodation space 30.

[0094] Some embodiments of the present application also provide an energy storage system, which includes a power conversion device and at least one energy storage device as provided by the above technical solution, and the power conversion device is used to electrically connect the at least one energy storage device of the power generation device.

[0095] Some embodiments of the present application provide a battery device 20, which includes a battery cell 14 and a box body 1. The battery cell 14 is accommodated in a cavity 15 of the box body 1. The box body 1 includes a first wall portion 11. The first wall portion 11 is provided with a through hole 111 that penetrates along its thickness direction. An expansion structure 12 is located in the through hole 111 and is sealed and connected to the inner wall surface of the through hole 111 to separate the cavity 15 from the outside. The softening point of the expansion structure 12 is set to A, 90°C≤A≤120°C; the linear expansion coefficient of the expansion structure 12 is set to B, B≥70×10 -6 m / mK. In the above structure, since at least part of the first wall portion 11 in the box body 1 is provided with an expansion structure 12 that separates the cavity 15 from the outside, and the softening point of the expansion structure 12 is set to A, 90°C≤A≤120°C, when the battery cell 14 in the battery device 20 has thermal runaway, the discharge of substances from the battery cell 14 causes the temperature and pressure in the cavity 15 to rise, which softens the expansion structure 12 and deforms under the action of the pressure in the cavity 15, causing the first wall portion 11 to bulge outward, which not only increases the heat dissipation area of ​​the box body 1, but also reduces the increase in pressure in the cavity 15, so that the battery device 20 can quickly reduce pressure and temperature, which is beneficial to the reliability of the battery device 20.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein 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 present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: Battery cells; A box body is formed with a cavity, and the battery cell is accommodated in the cavity. The box body includes a first wall portion, at least part of which is provided with an expansion structure, and the expansion structure separates the cavity from the outside world; the softening point of the expansion structure is set to A, 90℃≤A≤120℃, and the expansion structure can be deformed after softening to expand the cavity.

2. The battery device according to claim 1, characterized in that: The linear expansion coefficient of the expansion structure is set to B, B≥70×10 -6 m / mK.

3. The battery device according to claim 1, characterized in that: The first wall portion is provided with a through hole penetrating along the thickness direction thereof, and the expansion structure is located in the through hole and is sealed and connected to the inner wall surface of the through hole.

4. The battery device according to claim 3, characterized in that: The inner wall surface of the through hole is provided with a concave portion sunken inwardly, and the outer peripheral surface of the expansion structure is provided with a protrusion, and the protrusion is inserted into the concave portion.

5. The battery device according to claim 3, characterized in that: The expansion structure is bonded to the inner wall surface of the through hole by adhesive, and the softening point of the adhesive is set to C, C>A.

6. The battery device according to claim 1, characterized in that: The first wall portion includes a first portion and a second portion connected to each other, the first portion is configured as the expansion structure, and the first portion and the second portion are an integrally formed structure.

7. The battery device according to claim 1, characterized in that: The box body further includes a second wall portion connected to the first wall portion, and the battery device further includes a pressure relief mechanism, which is arranged on the second wall portion and is used to connect the cavity with the outside.

8. The battery device according to claim 1, characterized in that: The expansion structure is an ethylene-vinyl acetate copolymer structure.

9. An energy storage device, characterized in that: include: At least one battery device according to any one of claims 1 to 8; The cabinet is formed with a storage space, the battery device is stored in the storage space, the first wall of the battery device is arranged toward the wall of the cabinet, and the expansion structure can contact the wall of the cabinet.

10. The energy storage device according to claim 9, characterized in that: The energy storage device further comprises an electrical module and a fire-fighting module. Both the electrical module and the fire-fighting module are arranged in the accommodating space. The electrical module is electrically connected to the battery device.

11. The energy storage device according to claim 9, characterized in that: At least one battery cluster is arranged in the accommodation space, and the battery cluster includes at least two battery devices.

12. An energy storage system, characterized in that: include: Power conversion devices; At least one energy storage device according to any one of claims 9 to 11, wherein the power conversion device is used to electrically connect the power generation device and at least one of the energy storage devices.

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