Energy storage device and energy storage system

Abstract

The utility model relates to an energy storage device and an energy storage system. The energy storage device comprises a box body and a battery, the box body comprises wall plates and a plurality of pressure relief plates, a containing cavity is defined by the wall plates, and a plurality of pressure relief openings communicated with the containing cavity are formed in the wall plates; the plurality of pressure relief plates are connected to the wall plate, and one pressure relief plate correspondingly seals one pressure relief opening; the battery is arranged in the accommodating cavity; the pressure relief plate is configured to be opened when the internal pressure of the box body reaches the opening pressure of the pressure relief plate so as to open the corresponding pressure relief opening; wherein the opening pressures of at least part of the pressure relief plates are different. According to the energy storage device, at least part of the pressure relief plates are set to be different in opening pressure, step-by-step opening of the multiple pressure relief plates can be achieved after the thermal runaway gas is burnt and exploded, and then step-by-step pressure relief and explosion venting of the energy storage device are achieved. By opening the pressure relief plate step by step, direct contact between the battery and external air after the pressure relief plate is opened can be reduced as much as possible, generation of open fire is reduced, the thermal runaway propagation speed is reduced, and the influence of accidents and disasters is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to an energy storage device and an energy storage system. BACKGROUND

[0002] A large number of batteries are stored in the energy storage device, and when the batteries are in thermal runaway, a large amount of combustible gas will be accumulated, which will cause the energy storage device to have a risk of combustion and explosion. In the related technology, a pressure relief plate is installed on the box body of the energy storage device, and when the combustible gas is in combustion and explosion, the pressure relief plate is opened to release pressure. However, after the pressure relief plate is opened, the batteries in the box body will be in contact with too much air, and the batteries will produce open flames in the oxygen-rich environment, which will accelerate the propagation of thermal runaway between the batteries and aggravate the disaster development. CONTENT OF THE UTILITY MODEL

[0003] In view of the above problems, the present application provides an energy storage device and an energy storage system, which can alleviate the problem of accelerated thermal runaway propagation after the pressure relief plate is opened to release pressure.

[0004] In a first aspect, the present application provides an energy storage device, comprising: a box body comprising a wall plate and a plurality of pressure relief plates, the wall plate enclosing a containing cavity, and a plurality of pressure relief openings being provided on the wall plate and being in communication with the containing cavity; the plurality of pressure relief plates being connected to the wall plate, and one pressure relief plate corresponding to one closed pressure relief opening; and a battery being arranged in the containing cavity; wherein the pressure relief plates are configured to be opened when the internal pressure of the box body reaches the opening pressure of the pressure relief plates, so as to open the corresponding pressure relief openings; and wherein the opening pressures of at least part of the pressure relief plates are different.

[0005] In the technical scheme of the embodiments of the present application, by setting the opening pressures of at least part of the pressure relief plates to be different, the step-by-step opening of the plurality of pressure relief plates after the combustion and explosion of the thermal runaway gas can be realized, and then the graded pressure relief and explosion relief of the energy storage device can be realized. By step-by-step opening of the pressure relief plates, the direct contact of the batteries with the external air after the opening of the pressure relief plates can be reduced as much as possible, the generation of open flames can be reduced, the propagation speed of thermal runaway can be reduced, and the influence of the accident disaster can be reduced. By graded pressure relief, the pressure release process can be more stable, the batteries and the box body structure can be protected, the stability of the energy storage device can be improved, the frequent opening and replacement requirements of the pressure relief plates can be reduced, and the maintenance cost and complexity of the energy storage device can be reduced. At the same time, the multi-stage pressure relief plates can also improve the safety redundancy of the energy storage device, and improve the safety and reliability.

[0006] In some embodiments, the areas of the surfaces of at least part of the pressure relief plates facing the inside of the box body are different in size. In this way, at least part of the pressure relief plates can be set to different opening pressures, so that the step-by-step opening of the plurality of pressure relief plates after the combustion and explosion of the thermal runaway gas can be realized, and then the graded pressure relief and explosion relief of the energy storage device can be realized.

[0007] In some embodiments, the box further comprises fasteners, and the pressure relief plate is fixedly connected to the wall plate through the fasteners; wherein, when the internal pressure of the box reaches the opening pressure of the pressure relief plate, the fasteners can be broken to open the pressure relief plate. In this way, the opening pressure of the pressure relief plate can be controlled by designing the number and specifications of the fasteners used to fix the pressure relief plate, which is conducive to opening the pressure relief plate at a set pressure, improving the pressure relief effect of the pressure relief plate, reducing the risk of explosion, and improving the safety of the energy storage device.

[0008] In some embodiments, the number of fasteners connected to at least part of the pressure relief plates is different. In this way, at least part of the pressure relief plates can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates after the explosion of the thermal runaway gas can be realized, and the graded pressure relief and explosion relief of the energy storage device can be realized.

[0009] In some embodiments, the diameters of the fasteners connected to at least part of the pressure relief plates are different. In this way, the cross-sectional areas of the fasteners used to fix at least part of the pressure relief plates can be different, and at least part of the pressure relief plates can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates after the explosion of the thermal runaway gas can be realized, and the graded pressure relief and explosion relief of the energy storage device can be realized.

[0010] In some embodiments, the materials of the fasteners connected to at least part of the pressure relief plates are different. In this way, the yield stresses of the fasteners used to fix at least part of the pressure relief plates can be different, and at least part of the pressure relief plates can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates after the explosion of the thermal runaway gas can be realized, and the graded pressure relief and explosion relief of the energy storage device can be realized.

[0011] In some embodiments, the pressure relief plate and the wall plate are integrally formed; the wall plate is provided with a groove, and the groove at least partially defines the pressure relief plate; the pressure relief plate is configured to be able to split along at least part of the groove to open the pressure relief plate. In this way, the pressure relief function is integrated on the wall plate, so that the box itself has a pressure relief function, realizing the integration of the structure, reducing the use of external pressure relief plates, reducing the need for equipment purchase and installation, reducing procurement and maintenance costs, and reducing material and manufacturing costs, thereby reducing overall costs, improving economic benefits, simplifying the installation process, reducing maintenance complexity, and improving production efficiency. Moreover, the pressure relief plate can directly respond to changes in the pressure inside the box, improving the efficiency of the pressure relief process, reducing the risk of explosion, and improving the safety of the energy storage device.

[0012] In some embodiments, the depths of the grooves around at least part of the pressure relief plates are different. In this way, at least part of the pressure relief plates can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates after the explosion of the thermal runaway gas can be realized, and the graded pressure relief and explosion relief of the energy storage device can be realized.

[0013] In some embodiments, the length and / or shape of the grooves around at least part of the pressure relief plate are different. In this way, at least part of the pressure relief plate can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates after the explosion of the thermal runaway gas can be realized, thereby realizing the graded pressure relief and explosion relief of the energy storage device.

[0014] In some embodiments, the pressure relief plate includes a first pressure relief plate, a second pressure relief plate, a third pressure relief plate, and a fourth pressure relief plate, the first pressure relief plate has a first opening pressure P1, the second pressure relief plate has a second opening pressure P2, the third pressure relief plate has a third opening pressure P3, and the fourth pressure relief plate has a fourth opening pressure P4, which satisfy: P1 < P2 < P3 < P4. In this way, four-stage pressure relief and explosion relief of the energy storage device is realized. Through four-stage pressure relief and explosion relief, the time of the entire pressure relief process is further prolonged, the time interval of the opening of each stage of pressure relief plate is more dispersed, the opening area of the pressure relief is minimized as much as possible, the direct contact opportunity of the battery and the external air is further reduced, the generation of open fire is reduced, the propagation speed of thermal runaway is reduced, the pressure inside the box can be quickly responded to, the pressure relief can be timely performed, the rapid increase of the pressure inside the box is slowed down, the pressure release process is more stable, the damage to other components is reduced, the frequent opening and replacement of the pressure relief plate is reduced, and the explosion relief cost is reduced.

[0015] In a second aspect, the present application provides an energy storage system, which includes the energy storage device in any of the above embodiments.

[0016] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limitations on the present application. Moreover, in the entire drawings, the same reference numerals are used to designate the same components. In the drawings:

[0018] Figure 1 The structural schematic diagram of the energy storage device provided by some embodiments of the present application is shown.

[0019] Figure 2 The structural schematic diagram of the battery provided by some embodiments of the present application is shown.

[0020] Figure 3 The structural schematic diagram of the box provided by some embodiments of the present application is shown.

[0021] Figure 4A top view of a box according to some embodiments of the application.

[0022] Figure 5 A schematic view of a box according to some other embodiments of the application.

[0023] Figure 6 A schematic view of a force on a pressure relief plate according to some embodiments of the application.

[0024] Figure 7 A top view of a pressure relief plate mounting structure according to some embodiments of the application.

[0025] Figure 8 A front view of a pressure relief plate mounting structure according to some embodiments of the application.

[0026] Figure 9 A schematic view of a pressure relief plate and a wall panel according to some other embodiments of the application.

[0027] Figure 10 A perspective cut view of a pressure relief plate and a wall panel according to some other embodiments of the application.

[0028] Figure 11 An enlarged view of a partial cut of a pressure relief plate and a wall panel according to some other embodiments of the application.

[0029] Figure 12 A schematic view of another pressure relief plate according to some other embodiments of the application.

[0030] Figure 13 A schematic view of yet another pressure relief plate according to some other embodiments of the application.

[0031] Figure 14 A schematic view of still another pressure relief plate according to some other embodiments of the application.

[0032] Figure 15 A schematic view of yet another pressure relief plate according to some other embodiments of the application.

[0033] Figure 16 A schematic view of yet another pressure relief plate according to some other embodiments of the application.

[0034] Reference signs in the detailed description of the embodiments are as follows:

[0035] 100, energy storage device; 10, box body; 101, containing cavity; 1, wall plate; 11, pressure relief port; 12, flange; 13, notched groove; 131, end; 14, weak part; 15, unsealed edge; 16, top wall; 17, bottom wall; 18, side wall; 2, pressure relief plate; 21, first pressure relief plate; 22, second pressure relief plate; 23, third pressure relief plate; 24, fourth pressure relief plate; 3, fastener; 20, battery; 201, battery cell; 202, shell; 2021, first part; 2022, second part. DETAILED DESCRIPTION

[0036] In order to make the above objectives, features and advantages of the present application more clear and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0037] In this document, reference to“an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. Those skilled in the art will understand that an embodiment described herein can be incorporated into any other embodiment even though it is described in connection with a different embodiment.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the use of the terms“including,”“comprising,”“having” and“with” in this specification and in the claims, and the like, are used inclusively and in the most inclusive sense and are intended to cover a wide variety of compositions and processes.

[0039] In the description of the embodiments of the present application, it should be understood that the terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In the description of the embodiments of the present application, the terms "first", "second" are used only for the purpose of description, to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the embodiments of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing together, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0042] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0044] It should be noted that an element referred to as "fixed to" or "provided on" another element can be directly on the other element or can have a middle element. An element is considered to be "connected" to another element, which can be directly connected to another element or can have a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the embodiments of the present application are only for the purpose of description, and do not represent the only implementation.

[0045] From the development of market situation, the application of the battery is more and more extensive. For example, the battery is applied to the power generation places such as hydropower, thermal power, wind power and solar power station or the energy storage device in the energy storage power system. The energy storage device usually includes a large number of batteries arranged in the box. The battery stores the electric energy by converting the electric energy into chemical energy, can release the electric energy in the power peak period, and can be charged in the power valley period, so as to balance the load of the power system by using the energy storage device, relieve the pressure of the grid peak regulation and frequency regulation, and improve the stability and reliability of the grid. The energy storage device can also be used as an emergency backup power supply to provide continuous and stable power supply when the power system fails or natural disasters occur. When the battery in the energy storage device occurs thermal runaway, a large amount of flammable gas such as hydrogen, carbon monoxide and vaporized electrolyte will be generated. If the flammable gas is not discharged in time, the gas concentration may be too high, and then the hot gas explosion may be caused.

[0046] In order to alleviate the problem of explosion of the energy storage device, a pressure relief plate is usually installed on the box of the energy storage device to realize the pressure relief function. The pressure relief plate can be automatically opened when the internal pressure of the box reaches a certain threshold value, and the internal gas is released. The pressure relief plate is opened in time to release pressure and reduce the risk of explosion when the explosion occurs.

[0047] In the related art, the multiple pressure relief plates installed in the energy storage device usually adopt the same opening pressure, and the multiple pressure relief plates are opened at the same time to release pressure and explosion after the flammable gas accumulated in the inside explodes. However, after the multiple pressure relief plates are opened at the same time, the contact area between the box and the outside increases, which leads to a large possibility that the battery in the box contacts with the outside air, the battery is easy to produce open fire in the oxygen-rich environment, and the fire will gradually intensify, thereby accelerating the propagation of thermal runaway between the batteries and aggravating the disaster development.

[0048] Based on the above consideration, in order to improve the problem that a large amount of open fire is produced after the battery in the box contacts with the air, thereby accelerating the propagation of thermal runaway, the present application designs an energy storage device, sets multiple different pressure relief plates arranged on the box to different opening pressures, and the multiple pressure relief plates are opened step by step after the thermal runaway gas explosion, so as to realize the staged explosion relief of the energy storage device. By opening the pressure relief plate step by step, the contact between the battery and the outside air after the pressure relief plate is opened is reduced as much as possible, the production of open fire is reduced, the propagation speed of thermal runaway is reduced, and the influence of the accident disaster is reduced.

[0049] The energy storage device disclosed in this application can be applied, but is not limited to, energy storage systems in power generation sites such as wind power, hydropower, photovoltaic, and thermal power plants to balance the voltage of power plants and alleviate the problem of large intermittent fluctuations in power generation. Of course, it can also be applied to other energy storage power systems, such as energy storage systems in power distribution sites, energy storage systems in large industrial, commercial, and residential sectors, backup power supplies, smart charging stations, and other emerging fields. It can provide intelligent load management for the transmission and distribution side, timely peak shaving and frequency regulation according to grid load conditions, and provide users with peak shaving and valley filling modes and stable power quality management, achieving electricity coverage, reducing social electricity costs, and improving power security for users. This helps reduce the contact between the battery and outside air after the pressure relief plate is opened, reducing the risk of open flames from the battery, slowing the propagation speed of thermal runaway, and improving safety.

[0050] According to some embodiments of this application, refer to Figures 1 to 5 , Figure 1 The following are schematic diagrams of the energy storage device in some embodiments of this application. Figure 2 The following are schematic diagrams of the battery structure in some embodiments of this application. Figure 3 The following are schematic diagrams of the structure of the box in some embodiments of this application. Figure 4 A top view of the housing in some embodiments of this application is shown. Figure 5 A schematic diagram of the casing structure in some other embodiments of this application is shown. This application provides an energy storage device 100. The energy storage device 100 includes a casing 10 and a battery 20 disposed within the casing 10. The casing 10 includes a wall panel 1 and a plurality of pressure relief plates 2. The wall panel 1 forms a receiving cavity 101, and the wall panel 1 is provided with a plurality of pressure relief ports 11 communicating with the receiving cavity 101. The plurality of pressure relief plates 2 are connected to the wall panel 1, and each pressure relief plate 2 corresponds to closing one pressure relief port 11. The battery 20 is disposed within the receiving cavity 101. The pressure relief plates 2 are configured to open when the internal pressure of the casing 10 reaches the opening pressure of the pressure relief plate 2, thereby opening the corresponding pressure relief port 11. The opening pressures of at least some of the pressure relief plates 2 are different.

[0051] The energy storage device 100 may include multiple batteries 20, which are centrally located inside the housing 10. The multiple batteries 20 are used to store or output electrical energy for use when needed.

[0052] The battery 20 can adopt various structures. For example, the battery 20 may include a battery module or a battery pack. (See reference...) Figure 2 The battery 20 may include a battery cell 201 and a casing 202, with the battery cell 201 housed within the casing 202. The casing 202 provides housing space for the battery cell 201, reducing the impact of liquids or other foreign matter on the charging or discharging of the battery cell 201. The casing 202 can employ various structures. For example, see reference...Figure 2 The shell 202 can include a first part 2021 and a second part 2022, which are mutually coverable, and together define a containing space for containing the battery monomer 201. The second part 2022 can be a hollow structure with one side open, and the first part 2021 can be a plate structure, which is coverable on the open side of the second part 2022 to make the first part 2021 and the second part 2022 together define the containing space; the first part 2021 and the second part 2022 can also be hollow structures with one side open, and the open side of the first part 2021 is coverable on the open side of the second part 2022. Of course, the shell 202 formed by the first part 2021 and the second part 2022 can be in various shapes, such as a cylinder, a cuboid, etc.

[0053] In the battery 20, the battery monomer 201 can be multiple, and the multiple battery monomers 201 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple battery monomers 201 are connected in series and in parallel. The multiple battery monomers 201 can be directly connected in series, in parallel, or in a mixed manner, and the whole formed by the multiple battery monomers 201 is contained in the shell 202 of the battery 20; of course, the battery 20 can also be that the multiple battery monomers 201 are first connected in series, in parallel, or in a mixed manner to form a battery module, and the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is contained in the shell 202. The battery 20 can also include other structures, for example, the battery 20 can also include a current collecting component for realizing the electrical connection between the multiple battery monomers 201. Each battery monomer 201 can be a secondary battery; it can also be a lithium ion battery, a lithium-sulfur battery, a sodium ion battery, or a magnesium ion battery, but is not limited thereto. The battery monomer 201 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, i.e., the battery monomer 201 is not limited to a square cell, but can also be a cylindrical cell, etc.

[0054] The box 10 is used to provide a storage space for the battery 20, which can reduce the influence of the environment, liquid, or other foreign matters on the storage or output of the battery 20. The shape of the box 10 is not specifically limited in the present application, for example, in some embodiments, the box 10 can be roughly in the shape of a square, a cylinder, a prism, etc. The wall plate 1 is in the shape of a plate, which can be but is not limited to a flat plate, an arc-shaped plate, a corrugated plate, etc. The material of the wall plate 1 can be but is not limited to copper, iron, aluminum, steel, and alloys thereof, etc. In some embodiments, referring to Figure 3 and Figure 5The box 10 can include a plurality of wall plates 1 connected and enclosed to form the accommodating cavity 101. For example, the plurality of wall plates 1 of the box 10 can include a top wall 16, a bottom wall 17, and a plurality of side walls 18. The top wall 16 is arranged opposite to the bottom wall 17, and the plurality of side walls 18 are connected between the top wall 16 and the bottom wall 17 to form the box 10 in a substantially cuboid shape.

[0055] Since the energy storage device 100 includes a plurality of batteries 20, and each battery 20 includes a plurality of battery cells 201, it can be understood that a large number of battery cells 201 are arranged in a concentrated manner. When the battery 20 in the box 10 experiences thermal runaway, a large amount of flammable gas will be generated. The large amount of flammable gas will gather, causing the pressure in the box 10 to increase sharply.

[0056] To timely release the internal pressure of the box 10 and discharge the flammable gas, a plurality of pressure relief openings 11 are arranged on the wall plate 1 of the box 10, and the pressure relief openings 11 are in communication with the accommodating cavity 101. The box 10 is also provided with a plurality of pressure relief plates 2 connected to the wall plate 1. The plurality of pressure relief plates 2 are used to correspondingly close the plurality of pressure relief openings 11. In some embodiments, when the plurality of pressure relief plates 2 are connected to the wall plate 1, the accommodating cavity 101 is in a sealed state. Of course, the accommodating cavity 101 can also be not completely sealed. The shape of the pressure relief plate 2 is not limited in the present application. For example, in some embodiments, the pressure relief plate 2 can have a substantially square, rectangular, triangular, trapezoidal, circular, or oblong shape.

[0057] The pressure relief plate 2 is used for pressure relief and explosion relief of the energy storage device 100 to improve the use safety of the energy storage device 100. Each pressure relief plate 2 has a corresponding opening pressure. The opening pressure of the pressure relief plate 2 refers to the pressure at which the pressure relief plate 2 needs to be opened to exert its pressure relief function. When the battery 20 in the accommodating cavity 101 experiences thermal runaway to generate a large amount of gas, causing the internal pressure of the box 10 to reach the opening pressure of the pressure relief plate 2, the pressure in the box 10 reaches the connection strength of the pressure relief plate 2 and the wall plate 1, causing the pressure relief plate 2 to at least partially separate from the wall plate 1, so that the pressure relief plate 2 is opened to open the corresponding pressure relief opening 11 of the pressure relief plate 2. The pressure relief plate 2 communicates the accommodating cavity 101 with the outside by opening the corresponding pressure relief opening 11, so that the gas generated by the battery 20 and the discharge medium can be discharged out of the box 10 to release the internal pressure of the box 10. In this way, the gas pressure in the box 10 can be reduced to reduce the risk of explosion, achieve pressure relief and explosion relief of the box 10, and improve the use safety of the energy storage device 100.

[0058] Since the pressure relief plate 2 is used in the scenario of thermal runaway of the battery 20, the pressure relief plate 2 needs to react stably and quickly, and timely reduce the air pressure inside the box 10 to reduce the explosion risk, achieve pressure relief and explosion relief of the box 10, and further improve the safety of the energy storage device 100. When the pressure relief plate 2 is relieved, the pressure relief plate 2 is passively opened relative to the box 10. Passive opening refers to that the structure of the pressure relief plate 2 is deformed or damaged under the action of pressure, and then the function of pressure relief and explosion relief is started. The pressure relief plate 2 can be preferentially opened relative to the box 10 to achieve passive explosion relief of the box 10. The explosion energy is preferentially released outward from the opened pressure relief port 11, which can reduce the damage degree of the energy storage device 100. The passive explosion relief of the box 10 refers to passive pressure relief and explosion relief, that is, the explosion relief mode when the pressure relief plate 2 is passively opened. It can be understood that passive is relative to active. Active explosion relief needs active control of sensors and controllers, while passive explosion relief does not need control of sensors and controllers, and can directly respond to the pressure change in the containing cavity 101, so that the passive explosion relief is more timely and has higher stability than the active explosion relief.

[0059] In the embodiment, the positions and the number of the wall plates 1 provided with the pressure relief ports 11 and the pressure relief plates 2 are not specifically limited. For example, in some embodiments, the wall plate 1 provided with the pressure relief port 11 can be the top wall 16 of the box 10, or the bottom wall 17 or the side wall 18, or the top wall 16 and the side wall 18 are both provided with the pressure relief port 11, etc. The number of the pressure relief ports 11 on the wall plate 1 can be at least two, and the number of the pressure relief plates 2 is the same as that of the pressure relief ports 11, for example, the number of the pressure relief ports 11 and the pressure relief plates 2 can be two, three, four, six, eight, etc. By providing multiple pressure relief ports 11 and multiple pressure relief plates 2, the pressure relief area can be increased, and the explosion relief capacity and efficiency of the energy storage device 100 can be improved.

[0060] The opening pressure of at least part of the pressure relief plates 2 is different, which means that the opening pressure of at least part of the pressure relief plates 2 is different from that of another part of the pressure relief plates 2. When the battery 20 is in thermal runaway, the pressure inside the box 10 gradually rises, first reaches the opening pressure of one part of the pressure relief plates 2, at this time, one part of the pressure relief plates 2 opens and releases part of the gas. The pressure inside the box 10 continues to rise and reaches the opening pressure of another part of the pressure relief plates 2, at this time, another part of the pressure relief plates 2 also opens and releases more gas. In this way, multiple pressure relief plates 2 are configured to open at different pressures inside the box 10 to relieve pressure, which can achieve at least two stages of opening of multiple pressure relief plates 2 after thermal runaway gas explosion, and gradually open multiple pressure relief ports 11, thereby achieving two or more stages of graded pressure relief of the energy storage device 100.

[0061] The staged pressure relief prolongs the time of the whole pressure relief process, disperses the time interval of the opening of each stage of the pressure relief plate 2, reduces the direct contact opportunity of each stage of the battery 20 and the external air, reduces the possibility of a large amount of combustible gas contacting the external air in a short time, and thus reduces the risk of generating an open flame. The staged pressure relief can be adjusted under different pressure conditions, reduces the impact wave effect caused by single pressure release, protects the battery 20 and the structure of the box 10, makes the pressure release process more stable, and reduces the instability of the energy storage device 100 caused by sudden stress drop. The staged pressure relief can reduce the frequent opening and replacement requirement of the pressure relief plate 2, and reduces the maintenance cost and complexity of the energy storage device 100. By setting multiple pressure relief plates 2, even if a stage of the pressure relief plate 2 fails, the pressure relief function can still be provided by the pressure relief plates 2 of other stages, and the safety redundancy of the energy storage device 100 is improved.

[0062] The energy storage device 100 of the embodiment of the present application can realize the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas, and thus realizes the staged pressure relief and explosion relief of the energy storage device 100. By step-by-step opening of the pressure relief plate 2, the direct contact of the battery 20 and the external air after the opening of the pressure relief plate 2 can be reduced as much as possible, the generation of an open flame is reduced, the thermal runaway propagation speed is reduced, and the influence of the accident disaster is reduced. By the staged pressure relief, the pressure release process can be more stable, the battery 20 and the structure of the box 10 can be protected, the stability of the energy storage device 100 is improved, the frequent opening and replacement requirement of the pressure relief plate 2 can be reduced, and the maintenance cost and complexity of the energy storage device 100 are reduced. Meanwhile, the multiple pressure relief plates 2 can also improve the safety redundancy of the energy storage device 100.

[0063] In some embodiments, referring to Figure 4 , the pressure relief plate 2 includes a first pressure relief plate 21, a second pressure relief plate 22, a third pressure relief plate 23, and a fourth pressure relief plate 24, the first pressure relief plate 21 has a first opening pressure P1, the second pressure relief plate 22 has a second opening pressure P2, the third pressure relief plate 23 has a third opening pressure P3, and the fourth pressure relief plate 24 has a fourth opening pressure P4, and P1

[0064] The wall plate 1 of the box 10 can be provided with at least four pressure relief openings 11, and at least four pressure relief plates 2 are connected to the wall plate 1, and the at least four pressure relief plates 2 have four different opening pressures. Among them:

[0065] The opening pressure of the first pressure relief plate 21 is P1, P1 is the smallest among the four opening pressures, so that the first pressure relief plate 21 opens first, releases a part of the gas when the pressure is initially increased, and reduces the rapid rise of the internal pressure of the box 10.

[0066] The second pressure relief plate 22 opens at a pressure P2, P2 > P1. When the pressure inside the box 10 continues to rise and reaches P2, the second pressure relief plate 22 opens, further releasing gas.

[0067] The third pressure relief plate 23 opens at a pressure P3, P3 > P2. As the pressure inside the box 10 continues to increase, the third pressure relief plate 23 opens when the pressure inside the box 10 reaches P3, releasing more gas.

[0068] The fourth pressure relief plate 24 opens at a pressure P4, P4 > P3. In the most extreme case, when the pressure inside the box 10 reaches P4, all the pressure relief plates 2 open, achieving maximum pressure relief.

[0069] The pressure relief process of the energy storage device 100 is as follows:

[0070] In the initial stage, when the battery 20 experiences thermal runaway, the pressure inside the box 10 gradually rises, first reaching the opening pressure P1 of the first pressure relief plate 21, and the first pressure relief plate 21 opens, releasing some gas. This stage can achieve a rapid response, initially reducing the pressure inside the box 10. At this time, the other pressure relief plates 2 do not need to activate the pressure relief function, thereby reducing the pressure relief opening area.

[0071] In the intermediate stage, if the pressure inside the box 10 continues to rise, reaching the opening pressure P2 of the second pressure relief plate 22, the second pressure relief plate 22 opens, further releasing gas. This stage balances the release rate and safety of the gas inside the box 10, slowing the rapid increase of the pressure inside the box 10.

[0072] In the later stage, as the pressure inside the box 10 continues to rise, reaching the opening pressure P3 of the third pressure relief plate 23, the third pressure relief plate 23 opens, releasing more gas. This stage can improve the efficiency of releasing gas at higher pressures, reducing the risk of explosion.

[0073] In the final stage, the pressure inside the box 10 reaches the most extreme case, i.e. reaches the opening pressure P4 of the fourth pressure relief plate 24, and the fourth pressure relief plate 24 opens, achieving maximum pressure relief. In this stage, multiple pressure relief plates 2 are opened in the extreme case to perform rapid explosion relief, which can improve the efficiency of pressure relief, improve safety, and improve the situation where the pressure inside the box 10 exceeds the designed bearing range.

[0074] By setting multiple pressure relief plates 2 to have four different opening pressures, four-stage pressure relief and explosion relief of the energy storage device 100 is achieved. Through four-stage pressure relief and explosion relief, the time of the entire pressure relief process is further extended, the time interval of opening of each stage of pressure relief plate 2 is more dispersed, the opening area of pressure relief is minimized as much as possible, the opportunity of direct contact of the battery 20 with external air is further reduced, the generation of open fire is reduced, the heat runaway propagation speed is reduced, the pressure change inside the box 10 can be quickly responded, the pressure inside the box 10 can be timely relieved, the pressure inside the box 10 is slowed down, the pressure release process is more stable, the damage to other components is reduced, the frequent opening and replacement of the pressure relief plate 2 is reduced, and the explosion relief cost is reduced.

[0075] In some embodiments, referring to Figure 3 and Figure 5 , the wall plate 1 of the box 10 includes a top wall 16, multiple pressure relief openings 11 are arranged on the top wall 16, and multiple pressure relief plates 2 are connected to the top wall 16.

[0076] By arranging the pressure relief opening 11 and the pressure relief plate 2 on the top wall 16 of the box 10, when the battery 20 is in heat runaway, the energy storage device 100 can be exploded from the top, the explosion overpressure is upwardly relieved, and the unreacted combustible gas inside the box 10 can be discharged, which can reduce the significant damage to the surrounding area of the energy storage device 100 or the casualties caused by explosion, and reduce the safety hazard to other surrounding equipment and personnel.

[0077] In some embodiments, the area of the surface of at least part of the pressure relief plate 2 facing the inside of the box 10 is different.

[0078] It can be understood that the force received by the pressure relief plate 2 is the pressure of the gas inside the box 10 on the surface of the pressure relief plate 2 facing the inside of the box 10. Referring to Figure 6 , Figure 6 a force schematic diagram of the pressure relief plate 2 in some embodiments of the present application is shown, in which the X direction is the long side direction of the pressure relief plate 2, the Y direction is the short side direction of the pressure relief plate 2, the Z direction is the thickness direction of the wall plate 1, and the hollow arrow indicates the direction of the pressure inside the box. Taking the shape of the pressure relief plate 2 as a rectangle as an example, the long side length of the pressure relief plate 2 is a, and the short side length is b, at this time the area S of the surface of the pressure relief plate 2 facing the inside of the box 10 should satisfy: S=a·b. The opening pressure of the pressure relief plate 2 can be set as pressure P. Then the force F received by the pressure relief plate 2 should satisfy: F=P·S=P·a·b. That is, P=F / S. It can be understood that in the case that the force F received by the pressure relief plate 2 is the same, the larger the area S of the surface of the pressure relief plate 2 facing the inside of the box 10, the smaller the opening pressure P of the pressure relief plate 2, and vice versa, the smaller the area S of the surface of the pressure relief plate 2 facing the inside of the box 10, the larger the opening pressure P of the pressure relief plate 2.

[0079] By setting the area of the surface of the at least partial pressure relief plate 2 facing the inside of the box 10 to be different, the at least partial pressure relief plate 2 can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas can be realized, and then the graded pressure relief and explosion relief of the energy storage device 100 can be realized.

[0080] In some embodiments, referring to Figure 3 , Figure 4 , Figure 7 and Figure 8 , Figure 7 shows a top view of the pressure relief plate 2 mounting structure in some embodiments of the present application, Figure 8 shows a front view of the pressure relief plate 2 mounting structure in some embodiments of the present application. The box 10 further comprises fasteners 3, and the pressure relief plate 2 is fixedly connected to the wall plate 1 through the fasteners 3. Among them, when the internal pressure of the box 10 reaches the opening pressure of the pressure relief plate 2, the fasteners 3 can be broken to open the pressure relief plate 2.

[0081] The pressure relief plate 2 can be fixedly connected to the wall plate 1 through the fasteners 3. Among them, the fasteners 3 can be but are not limited to bolts, rivets, etc. By setting the breaking point of the fasteners 3, when the internal pressure of the box 10 reaches the opening pressure of the pressure relief plate 2, the fasteners 3 mechanically break, causing the pressure relief plate 2 to separate from the wall plate 1, so that the pressure relief plate 2 opens to open the pressure relief port 11, so that the gas and the discharge medium generated by the battery 20 can be discharged out of the box 10, realizing rapid pressure relief and gas release. In this way, the gas pressure inside the box 10 can be reduced, thereby reducing the risk of explosion and achieving pressure relief and explosion relief of the box 10, improving the safety of the energy storage device 100.

[0082] The area of the surface of the pressure relief plate 2 facing the inside of the box 10 is S, the number of fasteners 3 fixing the pressure relief plate 2 is N, the cross-sectional area of a single fastener 3 is s, and the yield stress of the fastener 3 is t. When the internal pressure of the box 10 is P, the force F on the pressure relief plate 2 satisfies F=P·S. When the force F on the pressure relief plate 2 is converted to a single fastener 3, the tensile force f on a single fastener 3 satisfies f=F / N=P·S / N. At this time, the tensile stress t on the fastener 3 satisfies t=f / s=P·S / (N·s).

[0083] It can be understood that when the tensile stress t on the fastener 3 is greater than or equal to the yield stress t0 of the fastener 3 itself, the fastener 3 is pulled off, and the pressure relief plate 2 separates from the wall plate 1, so that the pressure relief plate 2 opens. That is, t0=P·S / (N·s), and the pressure relief plate 2 satisfies the opening condition, that is, P=t0·N·s / S.

[0084] In the case that the area S of the surface of the pressure relief plate 2 facing the inside of the box 10 is the same, by selecting the number N of the fasteners 3 used for fixing the pressure relief plate 2 and the specifications of the fasteners 3 (i.e. the yield stress t0 and the cross-sectional area s of the fasteners 3), etc., the opening pressure P of the pressure relief plate 2 can be controlled, which is conducive to opening the pressure relief plate 2 at the set pressure. For example, the number N of the fasteners 3 can be 6, 8, 10, 12, 16, etc. The yield limit t0 of the fasteners 3 is related to the material of the fasteners 3, for example, the material of the fasteners 3 can be but is not limited to carbon steel or stainless steel, etc. The cross-sectional area s of the fasteners 3 is related to the diameter of the fasteners 3, for example, the diameter of the fasteners 3 can be 1.4 mm, 1.6 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0085] In some embodiments, referring to Figure 7 and Figure 8 , a flange 12 is arranged on the wall plate 1 of the box 10 around the pressure relief port 11, and the pressure relief plate 2 is fixedly connected to the flange 12 by locking bolts or other fixing means, so as to fix the pressure relief plate 2 to the wall plate 1 at the pressure relief port 11.

[0086] By using multiple fasteners 3 to install the pressure relief plate 2 to the wall plate 1 of the box 10, by designing the number of fasteners 3 used for fixing the pressure relief plate 2 and the specifications of the fasteners 3, etc., the opening pressure of the pressure relief plate 2 can be controlled, which is conducive to opening the pressure relief plate 2 at the set pressure, and is conducive to improving the pressure relief effect of the pressure relief plate 2, reducing the risk of explosion, and improving the safety of the energy storage device 100.

[0087] In some embodiments, the number of fasteners 3 connected to at least part of the pressure relief plates 2 is different.

[0088] Since the opening pressure P of the pressure relief plate 2 satisfies P = t0·N·s / S, by setting the number N of fasteners 3 connected to at least part of the pressure relief plates 2 to be different, at least part of the pressure relief plates 2 can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas can be realized, and the step-by-step pressure relief and explosion relief of the energy storage device 100 can be realized.

[0089] In some embodiments, the diameters of the fasteners 3 connected to at least part of the pressure relief plates 2 are different.

[0090] Since the opening pressure P of the pressure relief plate 2 satisfies P = t0·N·s / S, by setting the diameters of the fasteners 3 connected to at least part of the pressure relief plates 2 to be different, i.e. the cross-sectional areas s of the fasteners 3 used for fixing at least part of the pressure relief plates 2 are different, at least part of the pressure relief plates 2 can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas can be realized, and the step-by-step pressure relief and explosion relief of the energy storage device 100 can be realized.

[0091] In some embodiments, the material of the fastener 3 connected to at least part of the pressure relief plate 2 is different.

[0092] Since the opening pressure P of the pressure relief plate 2 satisfies: P = t0·N·s / S, by setting the material of the fastener 3 connected to at least part of the pressure relief plate 2 to be different, i.e., the yield stress t0 of the fastener 3 used to fix at least part of the pressure relief plate 2 is different, at least part of the pressure relief plate 2 can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas can be realized, and thus the graded pressure relief and explosion relief of the energy storage device 100 can be realized.

[0093] In summary, by setting different pressure relief plates 2 to be fixedly connected to the wall plate 1 by fasteners 3 of different numbers, different diameters, or different materials, or by setting the areas of the surfaces of different pressure relief plates 2 facing the inside of the box 10 to be different, different pressure relief plates 2 can be set to have different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the explosion of the thermal runaway gas can be realized, and the demand for the graded pressure relief and explosion relief of the energy storage device 100 can be met.

[0094] In some embodiments, referring to Figure 5 , Figures 9 to 11 , Figure 9 FIG. 1 shows a structural schematic diagram of a pressure relief plate 2 and a wall plate 1 in some embodiments of the present application, Figure 10 FIG. 2 shows a perspective sectional view of a pressure relief plate 2 and a wall plate 1 in some embodiments of the present application, Figure 11 FIG. 3 shows a partial enlarged sectional view of a wall plate 1 and a pressure relief plate 2 in some embodiments of the present application. The Z direction in the figure is the thickness direction of the wall plate 1. The pressure relief plate 2 is integrally formed with the wall plate 1. The wall plate 1 is provided with a groove 13, and the groove 13 at least partially defines the pressure relief plate 2. The pressure relief plate 2 is configured to be able to split along at least part of the groove 13, so that the pressure relief plate 2 is opened.

[0095] The pressure relief plate 2 can be a pressure relief structure formed on the wall plate 1 by an integral forming process. The groove 13 can be provided on the wall plate 1. For example, the groove 13 can be formed by, but is not limited to, a punching or milling machining process. The groove 13 can be, but is not limited to, an annular groove, an arcuate groove, or a straight groove. The cross section (i.e., the section perpendicular to the extension direction of the groove 13) of the groove 13 can be, but is not limited to, a triangular shape, a trapezoidal shape, a rectangular shape, etc. The groove 13 can be provided on the side surface of the wall plate 1 facing the inside of the box 10, or can be provided on the side surface of the wall plate 1 away from the inside of the box 10, or can be provided on both sides of the wall plate 1 along the thickness direction Z.

[0096] Referring to Figure 11The wall plate 1 forms a weak portion 14 at the region where the groove 13 is arranged. For example, the bottom groove wall of the groove 13 can form the weak portion 14. The wall plate 1 is connected to the pressure relief plate 2 through the weak portion 14. It can be understood that, in the thickness direction Z of the wall plate 1, the thickness of the weak portion 14 is smaller than the thickness of the wall plate 1 and the thickness of the pressure relief plate 2, so that the weak portion 14 is more fragile and is more likely to break. That is, the region where the groove 13 is arranged is more fragile than other regions of the wall plate 1, and is more likely to break when subjected to the same pressure.

[0097] When the battery 20 in the accommodating cavity 101 generates a large amount of gas due to thermal runaway, causing the internal pressure of the box body 10 to reach the opening pressure of the pressure relief plate 2, the weak portion 14 can automatically break, so that the pressure relief plate 2 can break along at least part of the groove 13, and at least partially separate from the wall plate 1, so that the pressure relief plate 2 is opened to open the pressure relief port 11 to communicate the accommodating cavity 101 with the outside, so that the gas generated by the battery 20 and the discharge medium can be discharged out of the box body 10, thereby realizing the pressure relief and explosion relief function of the pressure relief plate 2. In this way, the gas pressure inside the box body 10 can be reduced, thereby reducing the risk of explosion, realizing the pressure relief and explosion relief of the box body 10, and improving the use safety of the energy storage device 100.

[0098] The length of the weak portion 14 is L. The length L of the weak portion 14 is the extension length of the groove 13 on the wall plate 1. For example, the pressure relief plate 2 is rectangular in shape, the long side length of the pressure relief plate 2 is a, and the short side length is b. The groove 13 surrounds the four sides of the pressure relief plate 2, that is, the weak portion 14 is arranged around the pressure relief plate 2. At this time, the length L of the weak portion 14 satisfies: L = 2·a + 2·b.

[0099] The thickness of the weak portion 14 is D. The thickness D of the weak portion 14 is the residual thickness of the wall plate 1 at the region where the groove 13 is arranged. For example, the thickness direction Z of the wall plate 1 is provided with grooves 13 on both sides. The thickness of the wall plate 1 is H, the depth of the groove 13 on one side is d1, and the depth of the groove 13 on the other side is d2. The thickness D of the weak portion 14 satisfies: D = H - d1 - d2.

[0100] The opening condition of the pressure relief plate 2 is that the weak portion 14 is subjected to a shearing force to break. The shearing area A of the weak portion 14 satisfies: A = L·D. The shearing force received by the weak portion 14 is equal to the force F received by the pressure relief plate 2. The area of the surface of the pressure relief plate 2 facing the inside of the box body 10 is S. When the internal pressure of the box body 10 is P, the force F received by the pressure relief plate 2 satisfies: F = P·S. When the force F received by the pressure relief plate 2 is converted to the weak portion 14, the shearing stress T received by the weak portion 14 satisfies: T = F / A = P·S / (L·D).

[0101] It can be understood that when the shear stress T received by the weakened portion 14 is greater than or equal to the yield stress T0 of the material of the wall plate 1, the weakened portion 14 is torn and broken, and the pressure relief plate 2 is at least partially separated from the wall plate 1, so that the pressure relief plate 2 is opened. That is, T0 = P·S / (L·D), the pressure relief plate 2 satisfies the condition of opening, that is, P = T0·L·D / S.

[0102] In the case where the area S of the surface of the pressure relief plate 2 facing the inside of the cabinet 10 is the same, since the material of the wall plate 1 is unchanged, that is, T0 is unchanged, the opening pressure P of the pressure relief plate 2 can be controlled by designing the depth (that is, the thickness D of the weakened portion 14) and the length (that is, the length L of the weakened portion 14) and other parameters of the notch 13, which is beneficial to opening the pressure relief plate 2 at a set pressure.

[0103] Since the notch 13 is directly formed on the wall plate 1 of the cabinet 10, the pressure relief plate 2 can be at least partially broken along the notch 13 when the energy storage device 100 is relieved, so as to open the pressure relief plate 2. The pressure relief plate 2 can achieve the same pressure relief effect as an externally connected pressure relief plate, and the pressure relief function is integrated on the wall plate 1, so that the cabinet 10 itself has a pressure relief function. In this way, other pressure relief devices can be omitted on the cabinet 10, thereby reducing the use of pressure relief devices such as externally connected pressure relief plates, reducing equipment purchase requirements, and reducing procurement and maintenance costs. Since the pressure relief plate 2 is integrally formed with the wall plate 1, the installation requirement of the pressure relief plate 2 is omitted, the installation position is reserved on the cabinet 10, and the corresponding fixing and sealing are omitted, the installation process is simplified, and the installation and maintenance complexity is reduced, which can improve the production efficiency.

[0104] By forming the notch 13 on the wall plate 1 of the cabinet 10, the pressure relief plate 2 can be formed on the wall plate 1, the pressure relief function is integrated on the wall plate 1, so that the cabinet 10 itself has a pressure relief function, the structure is integrated, the use of externally connected pressure relief plates can be reduced, the equipment purchase and installation requirements can be reduced, the procurement and maintenance costs can be reduced, and the material and manufacturing costs can be reduced, thereby reducing the overall cost, improving the economic benefit, simplifying the installation process, reducing the maintenance complexity, and improving the production efficiency. Moreover, the pressure relief plate 2 can directly respond to the pressure change in the cabinet 10, which can improve the efficiency of the pressure relief process, reduce the risk of explosion, and improve the safety of the energy storage device 100.

[0105] In some embodiments, the depth of the notch 13 around at least part of the pressure relief plate 2 is different.

[0106] Since the opening pressure P of the pressure relief plate 2 satisfies: P = T0·L·D / S, by setting the depth of the notches 13 around at least part of the pressure relief plate 2, that is, the thickness D of the weak part 14 around at least part of the pressure relief plate 2, to be different, at least part of the pressure relief plate 2 can be set to different opening pressures, so that the step-by-step opening of multiple pressure relief plates 2 after the thermal runaway gas explosion can be realized, and further the graded pressure relief and explosion relief of the energy storage device 100 can be realized.

[0107] In some embodiments, referring to Figure 9 , Figure 10 and Figures 12 to 16 , Figure 12 Fig. 2 shows a structural schematic diagram of another pressure relief plate 2 in some other embodiments of the present application, Figure 13 Fig. 3 shows a structural schematic diagram of still another pressure relief plate 2 in some other embodiments of the present application, Figure 14 Fig. 4 shows a structural schematic diagram of yet another pressure relief plate 2 in some other embodiments of the present application, Figure 15 Fig. 5 shows a structural schematic diagram of still another pressure relief plate 2 in some other embodiments of the present application, Figure 16 Fig. 6 shows a structural schematic diagram of yet another pressure relief plate 2 in some other embodiments of the present application. The length and / or shape of the notches 13 around at least part of the pressure relief plate 2 are different.

[0108] The length of the notch 13 refers to the length of the extension track of the notch 13 on the wall plate 1.

[0109] In some embodiments, referring to Figure 9 , Figure 10 and Figure 12 , the notch 13 can be a slot extending along a closed figure track, and the enclosed area of the notch 13 defines the pressure relief plate 2.

[0110] The notch 13 being a slot extending along a closed figure track means that the orthographic projection of the notch 13 on the wall plate 1 forms a closed figure. The closed figure can include but is not limited to polygons, circles, ellipses, oblongs, etc. For example Figure 9 and Figure 10 , the notch 13 can be a rectangular ring-shaped slot surrounded by four straight slot segments, at this time the length of the notch 13 is the sum of the lengths of the four straight slot segments, for example, the length of the straight slot segment located on the long side of the rectangle is a, and the length of the straight slot segment located on the short side of the rectangle is b, then the length L of the weak part 14 satisfies: L = 2·a + 2·b. For another example Figure 12 , the notch 13 can be an oblong ring-shaped slot surrounded by two straight slot segments and two semicircular slot segments, at this time the length of the notch 13 is the sum of the lengths of the two straight slot segments and the two semicircular slot segments.

[0111] In the embodiment, the groove 13 defines the pressure relief plate 2, the groove 13 surrounds the periphery of the pressure relief plate 2, the weakened portion 14 surrounds and connects to the contour boundary of the pressure relief plate 2, and the pressure relief plate 2 is connected to the wall plate 1 through the weakened portion 14. In the pressure relief process, after the pressure relief plate 2 is cracked along the groove 13, the pressure relief plate 2 defined by the groove 13 can be completely separated from the wall plate 1, thereby releasing the pressure and gas.

[0112] In some embodiments, the depth of the groove 13 at each position around the periphery of the pressure relief plate 2 in the thickness direction Z of the wall plate 1 is the same. In this way, the thickness of the weakened portion 14 at each position around the periphery of the pressure relief plate 2 can be the same, which is conducive to the simultaneous fracture of the weakened portion 14 around the periphery of the pressure relief plate 2, and is conducive to improving the opening efficiency of the pressure relief plate 2, thereby improving the pressure relief efficiency.

[0113] By arranging the groove 13 to extend along the closed figure trajectory, the pressure relief plate 2 defined by the groove 13 can be completely separated from the wall plate 1, the pressure relief area of the pressure relief plate 2 after opening is larger, the pressure and gas can be quickly released, thereby improving the pressure relief efficiency, and the length of the groove 13 around the periphery of the pressure relief plate 2 after full cracking is longer, which can have a lower opening pressure of the pressure relief plate 2, and the reaction of the pressure relief plate 2 is more sensitive.

[0114] In some embodiments, referring to Figures 13 to 16 , the groove 13 has at least two end portions 131, and the line between the at least two end portions 131 and the groove 13 together define the pressure relief plate 2.

[0115] The groove 13 can also extend along a non-closed figure trajectory, so that the orthographic projection of the groove 13 on the wall plate 1 also has at least two end portions 131. The groove 13 has an end face at the end portion 131. The line between the two end portions 131 refers to the line between the points of the end faces of the two end portions 131 on the orthographic projection of the pressure relief plate 2. The line between the at least two end portions 131 and the groove 13 together define the pressure relief plate 2, so that the adjacent two end portions 131 form an unsealed edge 15 of the pressure relief plate 2. The non-closed figure can include various shapes, such as a “U” shape, an “H” shape, an “X” shape, a double “Y” shape, a “V” shape, an arc shape, etc.

[0116] For example Figure 13As shown in FIG. 1, the groove 13 can be a "U" shaped groove formed by three straight groove segments, two of which are arranged in parallel, and the third of which is connected between the same side ends 131 of the two straight groove segments. At this time, the groove 13 has two ends 131, and the groove 13 surrounds three edges of the profile of the pressure relief plate 2, and the line between the two ends 131 and the groove 13 together define the pressure relief plate 2, and the two ends 131 form an unsealed edge 15 of the pressure relief plate 2. At this time, the length of the groove 13 is the sum of the lengths of the three straight groove segments, for example, the length of the straight groove segment located on the long side of the rectangle is a, and the length of the straight groove segment located on the short side of the rectangle is b, then the length L of the weak portion 14 satisfies: L = 2a + b. In the pressure relief process, the pressure relief plate 2 breaks along the groove 13, and the breakage can occur at the three groove segments surrounding the three edges of the pressure relief plate 2, and the pressure relief plate 2 is turned open around the unsealed edge 15 under the action of pressure, thereby releasing the pressure and gas.

[0117] For another example Figure 14 As shown in FIG. 1, the groove 13 can be a "U" shaped groove formed by three straight groove segments, two of which are arranged in parallel, and the third of which is connected between the same side ends 131 of the two straight groove segments. At this time, the groove 13 has two ends 131, and the groove 13 surrounds three edges of the profile of the pressure relief plate 2, and the line between the two ends 131 and the groove 13 together define the pressure relief plate 2, and the two ends 131 form an unsealed edge 15 of the pressure relief plate 2. At this time, the length of the groove 13 is the sum of the lengths of the three straight groove segments, for example, the length of the straight groove segment located on the long side of the rectangle is a, and the length of the straight groove segment located on the short side of the rectangle is b, then the length L of the weak portion 14 satisfies: L = 2a + b. In the pressure relief process, the pressure relief plate 2 breaks along the groove 13, and the breakage can occur at the three groove segments surrounding the three edges of the pressure relief plate 2, and the pressure relief plate 2 is turned open around the unsealed edge 15 under the action of pressure, thereby releasing the pressure and gas.

[0118] For another example Figure 15 As shown in FIG. 1, the groove 13 can be a "U" shaped groove formed by three straight groove segments, two of which are arranged in parallel, and the third of which is connected between the same side ends 131 of the two straight groove segments. At this time, the groove 13 has two ends 131, and the groove 13 surrounds three edges of the profile of the pressure relief plate 2, and the line between the two ends 131 and the groove 13 together define the pressure relief plate 2, and the two ends 131 form an unsealed edge 15 of the pressure relief plate 2. At this time, the length of the groove 13 is the sum of the lengths of the three straight groove segments, for example, the length of the straight groove segment located on the long side of the rectangle is a, and the length of the straight groove segment located on the short side of the rectangle is b, then the length L of the weak portion 14 satisfies: L = 2a + b. In the pressure relief process, the pressure relief plate 2 breaks along the groove 13, and the breakage can occur at the three groove segments surrounding the three edges of the pressure relief plate 2, and the pressure relief plate 2 is turned open around the unsealed edge 15 under the action of pressure, thereby releasing the pressure and gas.

[0119] For another example Figure 16As shown in the figure, the groove 13 can be formed by a straight line groove segment and four oblique straight line groove segments to form a double "Y" shaped groove, that is, two oblique straight line groove segments are connected to one end of the straight line groove segment, and the other two oblique straight line groove segments are connected to the other end of the straight line groove segment, and the included angle between the two oblique straight line groove segments at the same end of the straight line groove segment and the straight line groove segment is greater than 90 degrees and less than 180 degrees. At this time, the groove 13 has four end portions 131, and the line connecting the adjacent two end portions 131 and the groove 13 together define four pressure relief areas of the pressure relief plate 2, and the unsealed edge 15 of the pressure relief plate 2 is located between the corresponding adjacent two end portions 131. At this time, the length of the groove 13 is the sum of the lengths of the straight line groove segment and the four oblique straight line groove segments. During the pressure relief process, after the pressure relief plate 2 is cracked along the groove 13, each pressure relief area is turned over and opened around the respective unsealed edge 15 under the action of pressure, thereby releasing the pressure and gas.

[0120] In this way, the pressure relief plate 2 can form at least one pressure relief area that is turned over, and after the pressure relief plate 2 is cracked along the groove 13, the pressure relief area of the pressure relief plate 2 can be turned over and opened around the unsealed edge 15 under the action of pressure, facilitating the pressure relief of the pressure relief plate 2. The pressure relief plate 2 that is turned over and opened can reduce the scattering of fragments of the pressure relief plate 2, can reduce the risk of secondary injury, and can improve safety.

[0121] By designing the shape of the pressure relief plate 2, the pressure relief plate 2 can be opened at a specified position to form a pressure relief channel, and the success rate of the pressure relief plate 2 being automatically opened under the opening pressure can be improved, thereby achieving the same pressure relief effect as an external pressure relief plate.

[0122] By setting the shapes of the grooves 13 around at least part of the pressure relief plate 2 to be different, the lengths of the grooves 13 around at least part of the pressure relief plate 2 can be made to be different, that is, the lengths L of the weak portions 14 around at least part of the pressure relief plate 2 are different.

[0123] Since the opening pressure P of the pressure relief plate 2 satisfies P=T0·L·D / S, by setting the lengths and / or shapes of the grooves 13 around at least part of the pressure relief plate 2 to be different, that is, the lengths L of the weak portions 14 around at least part of the pressure relief plate 2 are different, at least part of the pressure relief plate 2 can be set to different opening pressures, thereby realizing the step-by-step opening of multiple pressure relief plates 2 after the thermal runaway gas explosion, and further realizing the step-by-step pressure relief and explosion relief of the energy storage device 100.

[0124] In summary, by setting the shapes and / or lengths of the grooves 13 around different pressure relief plates 2 to be different, the depths of the grooves 13 to be different, or the areas of the surfaces of different pressure relief plates 2 facing the inside of the box 10 to be different, different pressure relief plates 2 can have different opening pressures, thereby realizing the step-by-step opening of multiple pressure relief plates 2 after the thermal runaway gas explosion, and meeting the needs of the step-by-step pressure relief and explosion relief of the energy storage device 100.

[0125] According to some embodiments of the present application, the present application also provides an energy storage system. The energy storage system comprises the energy storage device 100 provided by any of the above embodiments.

[0126] The energy storage system can be an energy storage system of a wind power station, a photovoltaic power station, etc. The energy storage system of the power station can be composed of the energy storage device 100 disclosed in the present application.

[0127] Since the energy storage system has the same technical effects as the energy storage device 100 described above, no further description is given here.

[0128] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; 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 be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. An energy storage device, characterized in that, include: The enclosure includes wall panels and multiple pressure relief plates. The wall panels form a receiving cavity, and the wall panels are provided with multiple pressure relief ports that communicate with the receiving cavity. The multiple pressure relief plates are connected to the wall panels, and each pressure relief plate corresponds to and closes one pressure relief port. The battery is disposed within the receiving cavity; The pressure relief plate is configured to open when the internal pressure of the housing reaches the opening pressure of the pressure relief plate, so as to open the corresponding pressure relief port; At least some of the pressure relief plates have different opening pressures.

2. The energy storage device according to claim 1, characterized in that, At least some of the pressure relief plates have different surface areas facing the inside of the housing.

3. The energy storage device according to claim 1 or 2, characterized in that, The enclosure also includes fasteners, and the pressure relief plate is fixedly connected to the wall panel by a plurality of the fasteners; When the internal pressure of the housing reaches the opening pressure of the pressure relief plate, multiple fasteners can break, thereby opening the pressure relief plate.

4. The energy storage device according to claim 3, characterized in that, The number of fasteners connected to at least some of the pressure relief plates is different.

5. The energy storage device according to claim 3, characterized in that, At least some of the fasteners connected to the pressure relief plates have different diameters.

6. The energy storage device according to claim 3, characterized in that, At least some of the fasteners connected to the pressure relief plates are made of different materials.

7. The energy storage device according to claim 1 or 2, characterized in that, The pressure relief plate is integrally formed with the wall panel; The wall panel is provided with a groove that at least partially defines the pressure relief plate; the pressure relief plate is configured to split along at least a portion of the groove to open the pressure relief plate.

8. The energy storage device according to claim 7, characterized in that, The depth of the grooves around at least some of the pressure relief plates is different.

9. The energy storage device according to claim 7, characterized in that, The length and / or shape of the grooves around at least part of the pressure relief plate are different.

10. The energy storage device according to claim 1 or 2, characterized in that, The pressure relief plate includes a first pressure relief plate, a second pressure relief plate, a third pressure relief plate, and a fourth pressure relief plate. The first pressure relief plate has a first opening pressure P1, the second pressure relief plate has a second opening pressure P2, the third pressure relief plate has a third opening pressure P3, and the fourth pressure relief plate has a fourth opening pressure P4, satisfying: P1 < P2 < P3 < P4.

11. An energy storage system, characterized in that, The energy storage system includes: an energy storage device as described in any one of claims 1 to 10.

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