Energy storage devices and electrical equipment

Abstract

This application discloses an energy storage device and an electrical appliance. The energy storage device includes a base, a first top cover, a battery module, and a venting structure. The first top cover and the base form a battery cavity. The first top cover has at least one venting structure with at least one first through hole. The battery module includes individual cells with explosion-proof valve holes. The position of the explosion-proof valve hole of the battery module corresponds to the position of the first through hole of the venting structure. The venting structure includes at least one venting component, which includes a valve and a venting sleeve made of a first shape memory alloy. At least one valve of the venting structure is respectively arranged at the opening of at least one first through hole of the venting structure. The valve is used to close or open the first through hole. When the venting sleeve is in a first state, the length of the venting sleeve is L1. When the venting sleeve is in a second state, the length of the venting sleeve is L2, and venting channels are formed inside, respectively communicating with the corresponding first through hole and the corresponding explosion-proof valve hole, where L1 < L2.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to an energy storage device and electrical equipment. Background Technology

[0002] The battery pack includes a housing and battery modules housed within the housing. Each battery module comprises multiple individual cells arranged side-by-side. When one of the individual cells experiences thermal runaway, high-temperature, high-pressure gas is generated inside that cell. This gas instantly breaches the cell's explosion-proof valve and diffuses into the battery pack. The diffused high-temperature gas then spreads to adjacent individual cells, causing their temperatures to rise sharply and increasing the risk of thermal runaway in those adjacent cells. Summary of the Invention

[0003] This application provides an energy storage device and an electrical appliance to solve the problem that thermal runaway of one or more individual cells can cause thermal runaway of adjacent individual cells.

[0004] The energy storage device according to the embodiments of this application includes:

[0005] base;

[0006] A first top cover is connected to the base, and the first top cover and the base form a battery cavity; the first top cover has at least one ventilation structure, the ventilation structure has at least one first through hole, the first through hole penetrating the inner wall surface and the outer wall surface of the first top cover;

[0007] At least one battery module is disposed within the battery cavity and includes multiple individual cells, each individual cell having an explosion-proof valve port; along a first direction, the position of the explosion-proof valve port of at least one individual cell of the battery module corresponds to the position of at least one first through-hole of the venting structure; the first direction is the height direction of the individual cell; and

[0008] At least one venting structure, the venting structure including at least one venting component, the venting component including a valve and a venting sleeve made of a first shape memory alloy, the valve of the at least one venting component of the venting structure being respectively arranged at the opening of at least one first through hole of the venting structure, the valve having a closed state of closing the first through hole and an open state of opening the first through hole; the venting sleeve is located inside the battery cavity and along the first direction, the position of the venting sleeve of the at least one venting component of the venting structure corresponding to the position of the explosion-proof valve hole of at least one single cell of the battery module; one end of the venting sleeve is connected to the first top cover or the valve and extends along the first direction; the venting sleeve has a first state and a second state, the length of the venting sleeve is L1 when the venting sleeve is in the first state, the length of the venting sleeve is L2 when the venting sleeve is in the second state, and an venting channel is formed inside, the venting channel communicating with the corresponding first through hole and the corresponding explosion-proof valve hole respectively, L1 < L2.

[0009] The energy storage device of this application embodiment, by incorporating valves and a gas-conducting sleeve made of a first shape memory alloy, allows the gas-conducting sleeve corresponding to a single cell in the energy storage device to directly guide the high-temperature, high-pressure gas ejected from the single cell out of the battery pack when thermal runaway occurs. This minimizes the diffusion of the high-temperature, high-pressure gas into other areas of the battery cavity, thereby preventing thermal runaway of one single cell from causing thermal runaway of other adjacent cells, reducing the accumulation of pressure inside the battery cavity, and lowering the risk of explosion. Furthermore, because the gas-conducting sleeve is made of the first shape memory alloy, it can automatically deform under high temperatures to achieve the function of gas conduction, and automatically return to its original state when the temperature returns to normal. Therefore, the top cover and gas-conducting assembly can be reused, saving costs.

[0010] According to some embodiments of this application, when the gas guide sleeve is in the second state, the gas guide sleeve covers the edge of the opening of the explosion-proof valve hole of the single battery cell.

[0011] In the embodiments of this application, when a single cell experiences thermal runaway, the gas guide sleeve extends and covers the edge of the explosion-proof valve hole of the single cell. The gas guide sleeve seals the edge of the explosion-proof valve hole, ensuring that high-temperature and high-pressure gas can only flow into the gas guide channel and will not diffuse outward.

[0012] According to some embodiments of this application, the initial phase transition temperature of the first shape memory alloy is equal to the thermal runaway initiation temperature of the single cell.

[0013] In this embodiment, setting the initial phase transition temperature of the first shape memory alloy to be equal to the thermal runaway initiation temperature of the individual battery can prevent the gas guide sleeve from prematurely elongating and blocking the explosion-proof valve orifice of the individual battery, thus avoiding poor venting. Specifically, when the internal pressure of the individual battery increases, causing the explosion-proof valve to open, if the temperature of the ejected gas has not yet reached the thermal runaway initiation temperature of the individual battery, the gas guide sleeve remains unchanged and does not elongate. At this time, there is sufficient venting space above the explosion-proof valve orifice of the individual battery, allowing the gas inside the individual battery to quickly diffuse to the area where adjacent individual batteries are located. The speed at which the gas is discharged from the individual battery and diffuses to the surroundings is faster, reducing the risk of explosion of the individual battery. At the same time, since the temperature of the gas ejected from the individual battery is low at this time, the impact on the temperature rise of adjacent individual batteries is also small, and it will not cause thermal runaway of adjacent individual batteries. It can be seen that setting the initial phase transition temperature of the first shape memory alloy to be equal to the thermal runaway initiation temperature of the individual battery ensures that the depressurization rate of the individual battery in the early stage of valve opening is not affected, and reduces the impact of high-temperature and high-pressure gas on the temperature rise of adjacent individual batteries.

[0014] According to some embodiments of this application, the first shape memory alloy is a heat-elongated shape memory alloy.

[0015] According to some embodiments of this application, the air guide sleeve includes a sleeve and a convex ring, the sleeve is connected to the first upper cover or the valve, and the convex ring protrudes from the outer peripheral side of the sleeve;

[0016] The side surface of the sleeve facing the single cell is the first surface, and the side surface of the convex ring facing the single cell is the second surface. The first surface and the second surface are flush and form an annular covering surface.

[0017] When the gas guide sleeve is in the second state, the annular covering surface covers the edge of the explosion-proof valve hole of the single battery cell.

[0018] In this embodiment, a convex ring is provided at the end of the sleeve furthest from the valve, and the first surface of the sleeve and the second surface of the convex ring form an annular covering surface. When the gas guide sleeve is in the second state, the annular covering surface covers the edge of the explosion-proof valve hole of the individual battery. The annular covering surface increases the contact area between the gas guide sleeve and the individual battery, further reducing the risk of high-temperature and high-pressure gas ejected from the individual battery diffusing outward from the gap between the gas guide sleeve and the individual battery.

[0019] According to some embodiments of this application, the orthographic projection of the gas guide sleeve on a target plane is an annular shape and is defined as the first projection. The orthographic projection of the explosion-proof valve hole of the single battery corresponding to the gas guide sleeve on the target plane is the second projection. The second projection is located within the area enclosed by the inner circle of the first projection. The target plane is perpendicular to the first direction.

[0020] In this embodiment of the application, the second projection is located within the area enclosed by the inner circle of the first projection. When the gas guide sleeve is in the second state, the gas guide sleeve can completely cover the explosion-proof valve hole, so that the high-temperature gas can quickly enter the preset gas guide channel and prevent the high-temperature gas from spreading to other areas of the battery cavity.

[0021] According to some embodiments of this application, the orthographic projection of the air guide sleeve on a target plane is an annular shape and is defined as the first projection. The orthographic projection of the first through hole corresponding to the air guide sleeve on the target plane is the third projection. The third projection is located within the area enclosed by the inner circle of the first projection, or the boundary of the third projection coincides with the inner circle of the first projection; wherein, the target plane is perpendicular to the first direction.

[0022] In this embodiment, the third projection is located within the area enclosed by the inner circle of the first projection, or the boundary of the third projection coincides with the inner circle of the first projection. When the gas guide sleeve is in the second state, the gas guide sleeve will not block the first through hole, and high-temperature gas can enter the hollow cavity through the first through hole at a large flow rate, thereby improving the pressure relief capacity of the gas guide channel.

[0023] According to some embodiments of this application, the energy storage device further includes:

[0024] A second top cover is connected to the first top cover, and the second top cover and the first top cover form a hollow cavity. The second top cover has a second through hole, and both the second through hole and the first through hole communicate with the hollow cavity. When the valve is in the open state, the battery cavity communicates with the hollow cavity through the second through hole.

[0025] The explosion-proof valve on the box cover is connected to the second upper cover and seals the second through hole.

[0026] In this embodiment, the high-temperature, high-pressure gas ejected from a single battery cell enters the hollow cavity through a gas guide sleeve, and then escapes by breaking through the explosion-proof valve on the casing. The hollow cavity serves as the channel for the high-temperature, high-pressure gas to escape from the battery cavity, preventing the high-temperature gas from diffusing within the battery cavity and reducing the risk of high-voltage arcing of components inside the energy storage device under the influence of charged high-temperature airflow.

[0027] According to some embodiments of this application, the valve is a one-way valve and is configured to allow fluid to enter the hollow cavity from the battery cavity through the one-way valve, while prohibiting fluid from entering the battery cavity from the hollow cavity through the one-way valve.

[0028] In the embodiments of this application, the arrangement of the one-way valve ensures that the high-temperature gas ejected from the single cell that has experienced thermal runaway can only enter the hollow cavity from the battery cavity, and cannot flow back from the hollow cavity to the battery cavity, thus preventing the gas from flowing back to the area where other single cells are located in the battery cavity and preventing other single cells from being affected by heat.

[0029] According to some embodiments of this application, the one-way valve includes:

[0030] A valve body is installed on the second upper cover and passes through the first through hole; the valve body has a valve cavity, the inner wall of the valve cavity has a valve port, and the portion of the valve body located between the first upper cover and the second upper cover also has an air outlet, the air outlet communicating with the hollow cavity and the valve cavity; the portion of the valve body extending into the battery cavity also has an air inlet, the air inlet communicating with the valve port;

[0031] A sealing element is movably disposed within the valve cavity for closing or opening the valve port;

[0032] An elastic element, disposed within the valve cavity, is used to provide an elastic force to the sealing element to close the valve port.

[0033] According to some embodiments of this application, the air guide sleeve is fitted around the outer periphery of the portion of the valve body that extends into the battery cavity, and the air inlet is located inside the air guide sleeve.

[0034] According to some embodiments of this application, the valve is a phase change element made of a second shape memory alloy, the phase change element is connected to the inner wall surface of the second upper cover, and the air guide sleeve is connected to the inner wall surface of the first upper cover;

[0035] Wherein, the length of the phase change element when it is in the closed state is L3, and it closes the first through hole; the length of the phase change element when it is in the open state is L4, and it opens the first through hole, where L3 > L4.

[0036] According to some embodiments of this application, the initial phase transition temperature of the second shape memory alloy is lower than that of the first shape memory alloy.

[0037] In this embodiment, since the initial phase transition temperature of the second shape memory alloy is lower than that of the first shape memory alloy, when thermal runaway occurs, the phase change element will shrink preferentially before the gas guide sleeve. Thus, when the high-temperature gas enters the gas guide channel of the gas guide sleeve, the phase change element is already in the open state with the first through hole open. At this time, the high-temperature gas can smoothly pass through the first through hole and enter the hollow cavity, avoiding the situation where the gas guide sleeve has already stretched while the phase change element remains in the closed state with the first through hole closed.

[0038] According to some embodiments of this application, the second shape memory alloy is a heat-shrinkable shape memory alloy.

[0039] The electrical equipment in this application embodiment includes the energy storage device described in any of the above claims, and the energy storage device supplies power to the electrical equipment. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0041] Figure 1 The diagram shown is a structural schematic of a residential energy storage system.

[0042] Figure 2 The diagram shown is a perspective view of an energy storage device according to the first embodiment of this application.

[0043] Figure 3 What is shown is Figure 2 A schematic diagram of its breakdown.

[0044] Figure 4 The diagram shows along Figure 3 A schematic diagram obtained after cutting the top cover along the AA section line.

[0045] Figure 5 The diagram shows along Figure 2 A schematic diagram obtained after cutting the battery pack through the BB cutting line.

[0046] Figure 6 What is shown is Figure 5 A magnified view of point X1 in the middle.

[0047] Figure 7 The diagram shown is a three-dimensional schematic of the air guide sleeve and valve after assembly.

[0048] Figure 8 The diagram shows the positional relationship between the first projection and the second projection.

[0049] Figure 9 The diagram shows the positional relationship between the third and fourth projections.

[0050] Figure 10 The diagram shown is a schematic diagram of the energy storage device of the first embodiment of this application when a single cell has not experienced thermal runaway.

[0051] Figure 11 The diagram shows the gas flow path when one of the individual cells in the energy storage device of the first embodiment of this application experiences thermal runaway.

[0052] Figure 12 The diagram shown is a schematic of an energy storage device according to a second embodiment of this application, wherein the individual battery cells do not experience thermal runaway.

[0053] Figure 13 The diagram shown is a schematic of an energy storage device according to a second embodiment of this application, wherein a single cell experiences thermal runaway.

[0054] Figure 14 The diagram shown is a schematic diagram of an energy storage device according to a third embodiment of this application.

[0055] Figure 15 The diagram shown is a schematic of an electrical device according to an embodiment of this application.

[0056] The reference numerals in the attached figures are explained as follows:

[0057] 1. Energy storage devices; 2. Power conversion devices; 3. User loads; 4. Electrical equipment;

[0058] 100, base; 100a, battery compartment;

[0059] 200, Top cover; 210, First top cover; 210a, Ventilation structure; 211, First through hole; 220, Second top cover; 221, Second through hole; 222, Threaded hole; 230, Hollow cavity; 240, Explosion-proof valve for the box cover;

[0060] 300. Battery module; 310. Individual battery cell; 311. Explosion-proof valve port;

[0061] 400, Air guiding structure; 400a, Air guiding assembly; 410, Valve; 410a, Check valve; 410b, Phase change element; 411, Valve body; 4111, Valve cavity; 4112, Valve port; 4113, Air outlet; 4114, Air inlet; 412, Sealing element; 413, Elastic element; 414, Valve seat; 420, Air guiding sleeve; 420a, Sleeve; 420b, Convex ring; 4221, First surface; 423, Air guiding channel; 424, Second surface; 425, Annular covering surface;

[0062] 500, Cold-rolled steel plate;

[0063] D1, First Direction; D2, Second Direction; D3, Third Direction;

[0064] S1, First projection; S2, Second projection; S3, Third projection. Detailed Implementation

[0065] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0066] It is understood that the terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to these processes, methods, products, or devices.

[0067] Since the energy people need is highly time- and space-dependent, in order to make rational use of energy and improve energy efficiency, it is necessary to use a medium or device to store one form of energy in the same way or by converting it into another form of energy, and then release it in a specific form of energy based on future application needs.

[0068] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices include:

[0069] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak regulation and frequency regulation.

[0070] (2) Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios (banks, shopping malls, etc.) and small household energy storage boxes used in residential energy storage scenarios primarily operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity consumption during peak and off-peak periods, users with energy storage devices typically charge the cabinets / boxes during off-peak hours to reduce costs; during peak hours, they release the stored electricity for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the existence of household energy storage devices effectively provides backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0071] This explanation will take the residential energy storage scenario in user-side energy storage as an example. Figure 1 A residential energy storage system is illustrated, comprising an energy storage device 1, a power conversion device 2 (such as a photovoltaic panel), and user loads 3 (such as streetlights, household appliances, etc.). The energy storage device 1 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the power conversion device 2 can convert solar energy into electrical energy during periods of low electricity prices and store it through the energy storage device 1, then supply it to the user loads 3 during periods of high electricity prices, or supply it to the user loads 3 during power outages / power interruptions.

[0072] In conjunction with the aforementioned energy storage methods using physical or electrochemical means, taking electrochemical energy storage as an example, the energy storage device 1 includes at least one set of chemical batteries. The chemical elements within these batteries serve as the energy storage medium, and the charging and discharging process is achieved through the chemical reactions or changes in the storage medium. Simply put, electrical energy generated from solar or wind power is stored in at least one set of chemical batteries through the chemical reactions or changes in the storage medium. When external power consumption reaches its peak, the stored energy is released through the chemical reactions or changes in the storage medium for use, or transferred to areas with power shortages.

[0073] like Figure 2 As shown, this application provides an energy storage device 1, which may be, but is not limited to, a battery pack, and an energy storage cabinet, energy storage container, etc., including the battery pack. The following description uses a battery pack as an example of the energy storage device 1.

[0074] like Figure 3 As shown, the battery pack includes a base 100, a top cover 200, at least one battery module 300, and a cold plate 500. The top cover 200 and the base 100 are connected, and the top cover 200 and the base 100 form a battery cavity 100a (e.g., Figure 5At least one battery module 300 is disposed within the battery cavity 100a. A cold plate 500 is arranged on the bottom surface of the battery module 300.

[0075] The shape of the base 100 and the top cover 200 after connection can have various embodiments, such as a hollow cube, a hollow cuboid, or other suitable shapes.

[0076] As an example, the base 100 is a cuboid shape with an opening, and the cold plate 500 and the battery module 300 are installed inside the base 100 through the opening. The top cover 200 can be plate-shaped, and the top cover 200 is fastened to the opening of the base 100 to form the battery cavity 100a.

[0077] In other embodiments, both the base 100 and the top cover 200 can be cuboid in shape and have an opening on one side. The opening of the base 100 is opposite to the opening of the top cover 200, and the top cover 200 and the base 100 are fastened together to form a battery cavity 100a for accommodating the battery module 300.

[0078] like Figure 3 As shown, the number of battery modules 300 can be one or more, or more than two. Each battery module 300 includes multiple individual battery cells 310 arranged side-by-side. These individual battery cells 310 can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0079] The single cell 310 has an explosion-proof valve port 311. The single cell 310 also has an explosion-proof valve, which is located at the explosion-proof valve port 311. When the single cell 310 experiences thermal runaway, the high-temperature and high-pressure gas generated inside the single cell 310 will break through the explosion-proof valve and then be ejected from the explosion-proof valve port 311.

[0080] For ease of explanation, the height direction of a single battery cell 310 is defined as the first direction D1, the length direction of a single battery cell 310 is defined as the second direction D2, and the width direction of a single battery cell 310 is defined as the third direction D3. The first direction D1, the second direction D2, and the third direction D3 are all perpendicular to each other. When there are multiple battery modules 300, the multiple battery modules 300 are arranged side-by-side along the second direction D2. The multiple single batteries 310 of the battery module 300 are arranged side-by-side along the third direction D3.

[0081] like Figure 4 and Figure 5As shown, the upper cover 200 includes a first upper cover 210 and a second upper cover 220. The first upper cover 210 is connected to the base 100, and the first upper cover 210 and the base 100 form a battery cavity 100a. The second upper cover 220 is connected to the first upper cover 210, and the second upper cover 220 and the first upper cover 210 form a hollow cavity 230.

[0082] In one embodiment, the first upper cover 210 and the second upper cover 220 may be connected by welding, but this is not a limitation.

[0083] The first top cover 210 has at least one venting structure 210a, and the venting structure 210a has a plurality of first through holes 211, which penetrate the inner wall and outer wall of the first top cover 210. Along the first direction D1, the positions of the plurality of explosion-proof valve holes 311 of the battery module 300 correspond to the positions of the plurality of first through holes 211 of the venting structure 210a.

[0084] For example, there can be one or more ventilation structures 210a. When there are multiple ventilation structures 210a, they can be arranged at intervals along the second direction D2. The multiple first through holes 211 of the ventilation structure 210a can be arranged along the third direction D3.

[0085] The inner wall surface of the first upper cover 210 refers to the side surface facing the battery cavity 100a, and the outer wall surface of the first upper cover 210 refers to the side surface facing away from the battery cavity 100a.

[0086] In the embodiments of this application, the number of battery modules 300 is the same as the number of venting structures 210a, and the number of first through holes 211 included in the battery module 300 is the same as the number of first through holes 211 included in the venting structure 210a. For example, in one embodiment, the battery pack includes two battery modules 300, each battery module 300 including four individual batteries 310, each individual battery 310 having one explosion-proof valve hole 311. The first top cover 210 has two venting structures 210a, each venting structure 210a having four first through holes 211. Along the first direction D1, the positions of the eight explosion-proof valve holes 311 correspond to the positions of the eight first through holes 211.

[0087] Of course, the number of battery modules 300 and the number of ventilation structures 210a are not limited to two. For example, the number of battery modules 300 and ventilation structures 210a can both be one, three, or other numbers. Similarly, the number of individual battery cells 310 included in the battery module 300 and the number of first through holes 211 included in the ventilation structure 210a are not limited to four. For example, they can be two, three, five, six, eight, or other numbers.

[0088] like Figure 2As shown, the second upper cover 220 has a second through hole 221, which penetrates both the inner and outer wall surfaces of the second upper cover 220. Both the second through hole 221 and the first through hole 211 communicate with the hollow cavity 230. The inner wall surface of the second upper cover 220 refers to the surface facing the hollow cavity 230, and the outer wall surface refers to the surface facing away from the hollow cavity 230.

[0089] The battery pack also includes a cover explosion-proof valve 240, which is connected to the second upper cover 220 and seals the second through hole 221. When the gas pressure in the hollow cavity 230 exceeds the explosion threshold of the cover explosion-proof valve 240, the gas in the hollow cavity 230 can break through the cover explosion-proof valve 240 and be ejected through the second through hole 221.

[0090] In one embodiment, the explosion-proof valve 240 of the box cover can be connected to the second upper cover 220 by welding, but this is not a limitation.

[0091] like Figure 3 , Figure 5 and Figure 6 As shown, the battery pack also includes at least one venting structure 400, which includes multiple venting components 400a. Each venting component 400a includes a valve 410 and a venting sleeve 420 made of a first shape memory alloy. The multiple valves 410 of the venting structure 400 are respectively arranged at the openings of multiple first through holes 211 of the venting structure 210a. The venting sleeve 420 is located inside the battery cavity 100a and extends along the first direction D1. The positions of the multiple venting sleeves 420 of the venting structure 400 correspond to the positions of the multiple explosion-proof valve holes 311 of the battery module 300. One end of the venting sleeve 420 is connected to the first upper cover 210 or the valve 410 and extends along the first direction D1.

[0092] The number of air-guiding structures 400 is the same as the number of battery modules 300, and the number of multiple air-guiding components 400a included in the air-guiding structure 400 is the same as the number of multiple individual battery cells 310 included in the battery module 300. There can be one or more air-guiding structures 400. When there are multiple air-guiding structures 400, they are arranged side-by-side along the second direction D2. The multiple air-guiding components 400a included in the air-guiding structure 400 are arranged along the third direction D3.

[0093] For example, such as Figure 2 As shown, there are two air guiding structures 400, and each air guiding structure 400 includes four air guiding components 400a, but this is not a limitation.

[0094] In other words, in the embodiments of this application, the number and position of the battery module 300, the ventilation structure 210a and the air guiding structure 400 correspond, and the number and position of the multiple single cells 310 included in a battery module 300, the multiple first through holes 211 included in a ventilation structure 210a and the multiple air guiding components 400a included in an air guiding structure 400 correspond.

[0095] like Figure 5 and Figure 6 As shown, valve 410 has a closed state (closing the first through hole 211) and an open state (opening the first through hole 211). When valve 410 is in the open state, battery cavity 100a is connected to hollow cavity 230 through second through hole 221. Gas guide sleeve 420 has a first state and a second state. When gas guide sleeve 420 is in the first state, its length is L1. When gas guide sleeve 420 is in the second state, its length is L2, and a gas guide channel 423 is formed inside. The gas guide channel 423 is connected to the corresponding first through hole 211 and the corresponding explosion-proof valve hole 311, respectively, where L1 < L2.

[0096] In one embodiment, the first shape memory alloy is a heat-elongating type, meaning that when the temperature of the gas guide sleeve 420 reaches the initial phase transformation temperature of the first shape memory alloy, the gas guide sleeve 420 automatically elongates. When the temperature of the gas guide sleeve 420 returns to room temperature, the gas guide sleeve 420 automatically shortens back to its original state.

[0097] Of course, it is understandable that the first shape memory alloy is not limited to the type that stretches when heated. For example, it can also be the type that bends or rotates when heated, as long as the shape of the gas guide sleeve 420 after heating can play the role of gas guide.

[0098] The following explanation will use the first shape memory alloy as an example, which exhibits thermal elongation. For ease of explanation, Figure 5 The four individual battery cells 310 in the module are designated A1, A2, A3, and A4 from left to right. A2 experienced thermal runaway, while A1, A3, and A4 did not. After thermal runaway occurred in A2, the high-temperature, high-pressure gas generated inside A2 breached the explosion-proof valve and was ejected from the explosion-proof valve port 311. According to the background art, the high-temperature, high-pressure gas ejected from A2 diffuses into other areas within the battery cavity 100a. This diffused high-temperature gas is reflected by the inner wall of the enclosure and directly impacts the surfaces of adjacent individual battery cells 310 (e.g., diffusing into A1 and A3, or even into A4, or into individual battery cells 310 of another battery module 300 arranged adjacent to this battery module 300). This causes a rapid increase in the temperature of adjacent individual battery cells 310, increasing the risk of thermal runaway in adjacent individual battery cells 310.

[0099] In this embodiment, the gas guiding assembly 400a includes a valve 410 and a gas guiding sleeve 420. When the single cell 310 does not experience thermal runaway, the valve 410 is in the closed state, closing the first through hole 211, and the gas guiding sleeve 420 is in the first state.

[0100] When thermal runaway occurs in A2, since the gas guide sleeve 420 is made of a first shape memory alloy, when the gas guide sleeve 420 corresponding to A2 is subjected to the high-temperature and high-pressure gas ejected from A2, and the temperature reaches the initial phase transition temperature of the first shape memory alloy, the gas guide sleeve 420 switches from a first state to a second state, that is, the length of the gas guide sleeve 420 extends from L1 to L2. After the gas guide sleeve 420 extends, the gas guide channel 423 formed inside it is connected to the corresponding first through hole 211 and explosion-proof valve hole 311, so that the high-temperature and high-pressure gas ejected from A2 can flow along the gas guide channel 423 and try not to diffuse into the area where the adjacent single cell 310 is located. The high-temperature and high-pressure gas flowing in the gas guide channel 423 can drive the valve 410 to switch from the closed state to the open state. When the valve 410 opens the first through hole 211, the gas can flow into the hollow cavity 230. When the gas pressure inside the cavity 230 reaches the threshold of the explosion-proof valve 240, the gas breaks through the explosion-proof valve 240 and is discharged from the battery pack.

[0101] Therefore, the energy storage device 1 of this application embodiment, by setting a valve 410 and a gas guide sleeve 420 made of a first shape memory alloy, can directly guide the high-temperature and high-pressure gas ejected from a single cell 310 directly out of the battery pack when a single cell 310 in the energy storage device 1 experiences thermal runaway. This minimizes the diffusion of the high-temperature and high-pressure gas to other areas within the battery cavity 100a, thereby preventing other adjacent cells 310 from also experiencing thermal runaway due to the thermal runaway of one single cell 310. This reduces the accumulation of pressure inside the battery cavity 100a and lowers the risk of explosion. Furthermore, since the gas guide sleeve 420 is made of the first shape memory alloy, it can automatically deform under high temperature to achieve the function of gas guidance, and can automatically return to its original state when the temperature returns to normal. Therefore, the top cover 200 and the gas guide assembly 400a can be reused, saving costs.

[0102] like Figure 6 As shown, when the gas guide sleeve 420 is in the second state, the gas guide sleeve 420 covers the edge of the opening of the explosion-proof valve hole 311 of the single cell 310. That is, when the gas guide sleeve 420 is in the second state, the end of the gas guide sleeve 420 away from the first through hole 211 is in contact with the edge of the opening of the explosion-proof valve hole 311 of the single cell 310.

[0103] In the embodiments of this application, when the single cell 310 experiences thermal runaway, the gas guide sleeve 420 extends and covers the edge of the explosion-proof valve hole 311 of the single cell 310. The gas guide sleeve 420 seals the edge of the explosion-proof valve hole 311, ensuring that high-temperature and high-pressure gas can only flow into the gas guide channel 423 and will not diffuse outward.

[0104] Of course, in other embodiments, when the gas guide sleeve 420 is in the second state, there may also be a small gap between the gas guide sleeve 420 and the single cell 310. The small gap does not affect the gas guide channel 423 from exporting most of the high temperature and high pressure gas generated by the single cell 310.

[0105] In one embodiment, the initial phase transition temperature of the first shape memory alloy is equal to the thermal runaway initiation temperature of the single cell 310.

[0106] In this embodiment, the initial phase transition temperature of the first shape memory alloy is set to be equal to the thermal runaway initiation temperature of the single cell 310. This avoids the gas guide sleeve 420 from prematurely elongating and blocking the explosion-proof valve hole 311 of the single cell 310, thus preventing poor venting. Specifically, when the internal pressure of the single cell 310 increases, causing the explosion-proof valve to open, if the temperature of the ejected gas has not yet reached the thermal runaway initiation temperature of the single cell 310, the gas guide sleeve 420 remains unchanged and does not elongate. At this time, there is sufficient venting space above the explosion-proof valve hole 311 of the single cell 310, allowing the gas inside the single cell 310 to quickly diffuse to the area where adjacent single cells 310 are located. The speed at which the gas is discharged from the single cell 310 and diffuses to the surroundings is faster, reducing the risk of explosion of the single cell 310. At the same time, since the temperature of the gas ejected from the single cell 310 is low at this time, the impact on the temperature rise of adjacent single cells 310 is also small, and it will not cause thermal runaway of adjacent single cells 310. Therefore, setting the initial phase transition temperature of the first shape memory alloy to be equal to the thermal runaway initiation temperature of the single cell 310 not only ensures that the depressurization rate of the single cell 310 is not affected in the early stage of valve opening, but also reduces the impact of high temperature and high pressure gas on the temperature rise of adjacent single cells 310.

[0107] It should be noted that "initial phase change temperature" refers to the temperature at which the shape memory alloy begins to deform, and "thermal runaway initiation temperature" refers to the temperature threshold at which the single cell 310 begins to experience thermal runaway when subjected to external factors or internal faults.

[0108] It is understandable that the thermal runaway initiation temperature of a single 310 cell is affected by a variety of factors, such as battery type, internal chemical composition, usage conditions and environment.

[0109] In one embodiment, the first shape memory alloy may include any one of the following: nickel-titanium alloy, copper-aluminum-nickel alloy, copper-zinc-aluminum alloy, iron-cobalt alloy, and nickel-aluminum alloy (Ni-Al alloy).

[0110] The initial phase transition temperature of the shape memory alloy can be controlled to be equal to the thermal runaway initiation temperature of the single cell 310 by controlling the alloy composition and heat treatment process. This allows the gas guide sleeve 420 to automatically extend when the gas temperature reaches the thermal runaway initiation temperature and automatically shorten and return to its original shape when the temperature is lower than the thermal runaway initiation temperature, ensuring that the gas guide sleeve 420 can be reused.

[0111] like Figure 7 As shown, the gas guide sleeve 420 includes a sleeve 420a and a convex ring 420b. The sleeve 420a is connected to the first upper cover 210 or the valve 410, and the convex ring 420b protrudes from the outer peripheral side of the sleeve 420a. The surface of the sleeve 420a facing the single cell 310 is the first surface 4221, and the surface of the convex ring 420b facing the single cell 310 is the second surface 424. The first surface 4221 and the second surface 424 are flush and form an annular covering surface 425. When the gas guide sleeve 420 is in the second state, the annular covering surface 425 covers the edge of the explosion-proof valve hole 311 of the single cell 310.

[0112] In this embodiment, a protruding ring 420b is provided at the end of the sleeve 420a away from the valve 410. The first surface 4221 of the sleeve 420a and the second surface 424 of the protruding ring 420b form an annular covering surface 425. When the gas guide sleeve 420 is in the second state, the annular covering surface 425 covers the edge of the explosion-proof valve hole 311 of the single battery 310. The annular covering surface 425 increases the contact area between the gas guide sleeve 420 and the single battery 310, further reducing the risk of high-temperature and high-pressure gas ejected from the single battery 310 diffusing outward from the gap between the gas guide sleeve 420 and the single battery 310.

[0113] In one embodiment, valve 410 is a one-way valve 410a, and the one-way valve 410a is configured to allow fluid from battery cavity 100a to enter hollow cavity 230 through one-way valve 410a, while prohibiting fluid from hollow cavity 230 to enter battery cavity 100a through one-way valve 410a.

[0114] In the embodiments of this application, the arrangement of the one-way valve 410a ensures that the high-temperature gas ejected from the single cell 310 that has experienced thermal runaway can only enter the hollow cavity 230 through the battery cavity 100a, and cannot flow back from the hollow cavity 230 to the battery cavity 100a, thereby preventing the gas from flowing back to the area where other single cells 310 are located in the battery cavity 100a and preventing other single cells 310 from being affected by heat.

[0115] In one embodiment, the one-way valve 410a is threadedly connected to the second upper cover 220. In this embodiment, the threaded connection between the one-way valve 410a and the second upper cover 220 facilitates the disassembly and assembly of the one-way valve 410a and the second upper cover 220, and makes subsequent maintenance easier.

[0116] like Figure 6 As shown, the one-way valve 410a includes a valve body 411, a sealing element 412, an elastic element 413, and a valve seat 414. The valve seat 414 and the second upper cover 220 can be connected by threads. For example, the second upper cover 220 has a threaded hole 222, the outer periphery of the valve seat 414 has external threads, and the valve seat 414 is screwed into the threaded hole 222.

[0117] The valve body 411 is connected to the valve seat 414 and passes through the first through hole 211. The valve body 411 has a valve cavity 4111, and the inner wall of the valve cavity 4111 has a valve port 4112. The portion of the valve body 411 located between the first upper cover 210 and the second upper cover 220 also has an air outlet 4113, which communicates with the hollow cavity 230 and the valve cavity 4111. The portion of the valve body 411 extending into the battery cavity 100a also has an air inlet 4114, which communicates with the valve port 4112. A sealing member 412 is movably disposed within the valve cavity 4111 for closing or opening the valve port 4112. An elastic member 413 is disposed within the valve cavity 4111 for providing the sealing member 412 with an elastic force to close the valve port 4112.

[0118] like Figure 6 As shown, thermal runaway occurred in A2. The high-temperature gas passed through the gas guide channel 423 of the gas guide sleeve 420 and entered the valve chamber 4111 through the gas inlet 4114. Under the action of gas pressure, the sealing member 412 overcame the elastic force provided by the elastic member 413 and moved upward. Then the sealing member 412 opened the valve port 4112, and the high-temperature gas flowed into the hollow cavity 230 through the valve port 4112 and the gas outlet 4113.

[0119] Since A1 did not experience thermal runaway, the sealing element 412 of the one-way valve 410a corresponding to A1 is sealed by the elastic force provided by the elastic element 413. At this time, the high-temperature gas ejected from A2 will not flow back into the battery cavity 100a through the one-way valve 410a corresponding to A1 after entering the hollow cavity 230.

[0120] In one embodiment, the valve body 411 is a cylindrical structure with openings at both ends. One end of the valve body 411 is connected to the valve seat 414, and the other end is connected to the air guide sleeve 420. As an example, the outer peripheral surface of the valve body 411 has external threads, and the valve body 411 is screwed to the valve seat 414.

[0121] In one embodiment, the elastic element 413 can be a spring, with one end abutting against the valve seat 414 and the other end abutting against the sealing element 412. Of course, the elastic element 413 can also be other components that can provide elastic force, such as rubber materials.

[0122] like Figure 6 As shown, the air guide sleeve 420 is sleeved on the outer periphery of the part of the valve body 411 that extends into the battery cavity 100a, and the air inlet 4114 is located inside the air guide sleeve 420.

[0123] For example, the air guide sleeve 420 and the valve body 411 can be connected by means of interference fit, threaded connection, riveting, etc., and this application does not make any special limitation on this.

[0124] It is understood that, in other embodiments, when the vent sleeve 420 is in the second state, the positional relationship between the vent sleeve 420 and the explosion-proof valve hole 311 of the single battery 310 can also be:

[0125] like Figure 8 As shown, the orthographic projection of the gas guide sleeve 420 on a target plane is an annular shape and is defined as the first projection S1. The orthographic projection of the explosion-proof valve hole 311 of the single cell 310 corresponding to the gas guide sleeve 420 on the target plane is the second projection S2. The second projection S2 is located within the area enclosed by the inner circle of the first projection S1. The target plane is perpendicular to the first direction D1.

[0126] In this embodiment of the application, the second projection S2 is located in the area enclosed by the inner circle of the first projection S1. When the gas guide sleeve 420 is in the second state, the gas guide sleeve 420 can completely cover the explosion-proof valve hole 311, so that the high-temperature gas can quickly enter the preset gas guide channel 423 and prevent the high-temperature gas from spreading to other areas of the battery cavity 100a.

[0127] like Figure 9 As shown, the orthographic projection of the air guide sleeve 420 on a target plane is an annular shape and is defined as the first projection S1. The orthographic projection of the first through hole 211 corresponding to the air guide sleeve 420 on the target plane is the third projection S3. The third projection S3 is located in the area enclosed by the inner circle of the first projection S1, or the boundary of the third projection S3 coincides with the inner circle of the first projection S1.

[0128] In this embodiment, the third projection S3 is located within the area enclosed by the inner circle of the first projection S1, or the boundary of the third projection S3 coincides with the inner circle of the first projection S1. When the air guide sleeve 420 is in the second state, the air guide sleeve 420 will not block the first through hole 211, and the high-temperature gas can pass through the first through hole 211 at a large flow rate and enter the hollow cavity 230, thereby improving the pressure relief capacity of the air guide channel 423.

[0129] The following combination Figure 10 and Figure 11 Detailed description of the trajectory of the high-temperature gas ejected when the 310 single cell experiences thermal runaway.

[0130] like Figure 10 As shown, none of the individual cells 310 experienced thermal runaway. At this time, valve 410 was in the closed state, closing the first through hole 211, and the vent sleeve 420 was in the first state. Furthermore, the explosion-proof valve 240 of the enclosure was in the closed state.

[0131] like Figure 11 As shown, when one or more individual cells 310 experience thermal runaway, and the high-temperature gas ejected during thermal runaway reaches the initial phase transition temperature of the gas guide sleeve 420, the gas guide sleeve 420 extends and covers the explosion-proof valve hole 311 of the individual cell 310. The high-temperature gas ejected from the individual cell 310 passes through the gas guide channel 423 of the gas guide sleeve 420, and switches the valve 410 to the open state, opening the first through hole 211. The high-temperature gas enters the hollow cavity 230, and when the gas pressure in the hollow cavity 230 reaches the explosion threshold of the explosion-proof valve 240 of the enclosure, it breaks through the explosion-proof valve 240 and is discharged.

[0132] like Figure 12 and Figure 13 As shown, in another embodiment, valve 410 can also be a phase change element 410b made of a second shape memory alloy, that is, replacing the one-way valve 410a in the above embodiment with phase change element 410b. Phase change element 410b is connected to the inner wall surface of the second upper cover 220, and air guide sleeve 420 is connected to the inner wall surface of the first upper cover 210.

[0133] When the phase change element 410b is in the closed state, its length is L3, and it closes the first through hole 211; when the phase change element 410b is in the open state, its length is L4, and it opens the first through hole 211, where L3 > L4.

[0134] In one embodiment, the phase change element 410b can be elongated, and its cross-sectional shape can be circular, rectangular, elliptical, or other shapes.

[0135] When the phase change element 410b is in the closed state, the end of the phase change element 410b can contact the edge of the opening of the first through hole 211, or the end of the phase change element 410b can be inserted into the first through hole 211.

[0136] In one embodiment, the second shape memory alloy is a heat-shrinking type, meaning that when the phase change element 410b is heated to the initial phase change temperature of the second shape memory alloy, the phase change element 410b automatically shrinks. When the temperature of the phase change element 410b returns to room temperature, the phase change element 410b automatically shrinks back to its original state.

[0137] Of course, it is understandable that the second shape memory alloy is not limited to the type that shrinks when heated. For example, it can also be the type that bends or rotates when heated, as long as the phase change element 410b can open the first through hole 211 after being heated and deformed, and close the first through hole 211 when at room temperature.

[0138] The following explanation will use the second shape memory alloy as an example of a heat-shrinkable type. Figure 12 As shown, none of the individual cells 310 experienced thermal runaway. At this time, the phase change element 410b was in the closed state, with a length of L3, and sealed the first through hole 211. Furthermore, the vent sleeve 420 was in the first state. Simultaneously, the explosion-proof valve 240 of the enclosure was also in the closed state.

[0139] like Figure 13 As shown, when one or more individual cells 310 experience thermal runaway, and the high-temperature gas ejected during thermal runaway reaches the initial phase change temperature of the gas guide sleeve 420, the gas guide sleeve 420 extends and covers the explosion-proof valve hole 311 of the individual cell 310. The high-temperature gas ejected from the individual cell 310 passes through the gas guide channel 423 of the gas guide sleeve 420, triggering the phase change element 410b. The phase change element 410b then shortens to L4, opening the first through hole 211, allowing the high-temperature gas to enter the hollow cavity 230 through the first through hole 211. When the gas pressure inside the hollow cavity 230 reaches the explosion threshold of the explosion-proof valve 240, it breaks through the explosion-proof valve 240 and is discharged.

[0140] It should be noted that when the high-temperature gas enters the hollow cavity 230, the gas temperature has relatively decreased and is insufficient to trigger the phase change elements 410b corresponding to the remaining unaffected individual cells 310. Therefore, the remaining phase change elements 410b remain in the closed state, i.e., the first through-hole 211 is closed. Thus, the remaining phase change elements 410b can effectively prevent the high-temperature gas from flowing back into the battery cavity 100a through the remaining first through-holes 211, and prevent the remaining individual cells 310 from experiencing thermal runaway due to the influence of the backflowing high-temperature gas.

[0141] In one embodiment, the initial phase transition temperature of the second shape memory alloy is lower than that of the first shape memory alloy.

[0142] In this embodiment, since the initial phase transition temperature of the second shape memory alloy is lower than that of the first shape memory alloy, when thermal runaway occurs, the phase change element 410b will shrink preferentially before the gas guide sleeve 420. Thus, when the high-temperature gas enters the gas guide channel 423 of the gas guide sleeve 420, the phase change element 410b is already in the open state of the first through hole 211. At this time, the high-temperature gas can smoothly pass through the first through hole 211 and enter the hollow cavity 230, avoiding the gas guide sleeve 420 from elongating while the phase change element 410b remains in the closed state of the first through hole 211.

[0143] like Figure 14 As shown, in another embodiment of the energy storage device 1 of this application, the upper cover 200 may not form a hollow cavity 230, but the upper cover 200 may only include a first upper cover 210 and not a second upper cover 220. A valve 410 is provided at the first through hole 211 of the first upper cover 210 for closing or opening the first through hole 211.

[0144] When one or more individual cells 310 experience thermal runaway, the gas guide sleeve 420 corresponding to that individual cell 310 extends, and the high-temperature gas passes through the gas guide channel 423 and valve 410 of the gas guide sleeve 420 in sequence before being directly discharged from the housing.

[0145] In one embodiment, valve 410 may be a one-way valve 410a and is configured to allow fluid to be discharged from battery chamber 100a through one-way valve 410a, while prohibiting fluid from entering battery chamber 100a from outside the battery pack through one-way valve 410a.

[0146] It should be noted that, in the above embodiments, the number of first through holes 211 in the venting structure 210a is not limited to multiple, for example, it can also be one. The number of air guiding components 400a in the air guiding structure 400 is not limited to multiple, for example, it can also be one.

[0147] Specifically, when the venting structure 210a has a first through hole 211 and the venting structure 400 has a venting assembly 400a, the valve 410 of the venting assembly 400a is arranged at the opening of the first through hole 211, and in the first direction D1, the position of the venting sleeve 420 of the venting assembly 400a corresponds to the position of the explosion-proof valve hole 311 of one of the individual cells 310 in the battery module 300. Thus, when one of the individual cells 310 in the battery pack experiences thermal runaway, the venting sleeve 420 can guide the high-temperature, high-pressure gas ejected from the individual cell 310 out of the battery pack, minimizing the diffusion of the high-temperature, high-pressure gas into other areas within the battery cavity.

[0148] It should also be noted that the number of first through holes 211 included in a venting structure 210a is equal to the number of air guiding components 400a included in a venting structure 400. The number of first through holes 211 included in a venting structure 210a may be less than or equal to the number of individual cells 310 included in a battery module 300.

[0149] like Figure 15 As shown, this application also provides an electrical device 4, including an energy storage device 1 according to any of the above claims, wherein the energy storage device 1 supplies power to the electrical device 4.

[0150] It is understood that the various embodiments / implementations provided in this application can be combined with each other without creating contradictions, and will not be described one by one here.

[0151] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0152] In the description of the embodiments of the application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the application.

[0153] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the claims. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0154] The above are merely preferred embodiments of the application examples and are not intended to limit the application examples. For those skilled in the art, the application examples can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application examples should be included within the protection scope of the application examples.

Claims

1. An energy storage device, characterized in that, include: base; A first upper cover is connected to the base, and the first upper cover and the base form a battery cavity; The first top cover has at least one ventilation structure, the ventilation structure having at least one first through hole, the first through hole penetrating the inner wall surface and the outer wall surface of the first top cover; At least one battery module is disposed within the battery cavity and includes multiple individual cells, each individual cell having an explosion-proof valve port; along a first direction, the position of the explosion-proof valve port of at least one individual cell of the battery module corresponds to the position of at least one first through hole of the ventilation structure; the first direction is the height direction of the individual cell; as well as At least one venting structure, the venting structure including at least one venting component, the venting component including a valve and a venting sleeve made of a first shape memory alloy, the valve of the at least one venting component of the venting structure being respectively arranged at the opening of at least one first through hole of the venting structure, the valve having a closed state of closing the first through hole and an open state of opening the first through hole; the venting sleeve is located inside the battery cavity and along the first direction, the position of the venting sleeve of the at least one venting component of the venting structure corresponding to the position of the explosion-proof valve hole of at least one single cell of the battery module; one end of the venting sleeve is connected to the first top cover or the valve and extends along the first direction; the venting sleeve has a first state and a second state, the length of the venting sleeve is L1 when the venting sleeve is in the first state, the length of the venting sleeve is L2 when the venting sleeve is in the second state, and an venting channel is formed inside, the venting channel communicating with the corresponding first through hole and the corresponding explosion-proof valve hole respectively, L1 < L2.

2. The energy storage device according to claim 1, characterized in that, When the gas guide sleeve is in the second state, the gas guide sleeve covers the edge of the opening of the explosion-proof valve hole of the single battery cell.

3. The energy storage device according to claim 1, characterized in that, The initial phase transition temperature of the first shape memory alloy is equal to the thermal runaway initiation temperature of the single cell.

4. The energy storage device according to claim 1, characterized in that, The first shape memory alloy is a heat-elongated shape memory alloy.

5. The energy storage device according to claim 1, characterized in that, The air guide sleeve includes a sleeve and a convex ring. The sleeve is connected to the first upper cover or the valve, and the convex ring protrudes from the outer peripheral side of the sleeve. The side surface of the sleeve facing the single cell is the first surface, and the side surface of the convex ring facing the single cell is the second surface. The first surface and the second surface are flush and form an annular covering surface. When the gas guide sleeve is in the second state, the annular covering surface covers the edge of the explosion-proof valve hole of the single battery cell.

6. The energy storage device according to claim 1, characterized in that, The orthographic projection of the gas guide sleeve on a target plane is an annular shape and is defined as the first projection. The orthographic projection of the explosion-proof valve hole of the single battery corresponding to the gas guide sleeve on the target plane is the second projection. The second projection is located within the area enclosed by the inner circle of the first projection. The target plane is perpendicular to the first direction.

7. The energy storage device according to claim 1, characterized in that, The orthographic projection of the air guide sleeve on a target plane is an annular shape and is defined as the first projection. The orthographic projection of the first through hole corresponding to the air guide sleeve on the target plane is the third projection. The third projection is located within the area enclosed by the inner circle of the first projection, or the boundary of the third projection coincides with the inner circle of the first projection. The target plane is perpendicular to the first direction.

8. The energy storage device according to any one of claims 1-7, characterized in that, The energy storage device also includes: A second top cover is connected to the first top cover, and the second top cover and the first top cover form a hollow cavity. The second top cover has a second through hole, and both the second through hole and the first through hole communicate with the hollow cavity. When the valve is in the open state, the battery cavity communicates with the hollow cavity through the second through hole. The explosion-proof valve on the box cover is connected to the second upper cover and seals the second through hole.

9. The energy storage device according to claim 8, characterized in that, The valve is a one-way valve and is configured to allow fluid to enter the hollow cavity from the battery cavity through the one-way valve, while prohibiting fluid from entering the battery cavity from the hollow cavity through the one-way valve.

10. The energy storage device according to claim 9, characterized in that, The one-way valve includes: A valve body is installed on the second upper cover and passes through the first through hole; the valve body has a valve cavity, the inner wall of the valve cavity has a valve port, and the portion of the valve body located between the first upper cover and the second upper cover also has an air outlet, the air outlet communicating with the hollow cavity and the valve cavity; the portion of the valve body extending into the battery cavity also has an air inlet, the air inlet communicating with the valve port; A sealing element is movably disposed within the valve cavity for closing or opening the valve port; An elastic element, disposed within the valve cavity, is used to provide an elastic force to the sealing element to close the valve port.

11. The energy storage device according to claim 10, characterized in that, The air guide sleeve is fitted onto the outer periphery of the portion of the valve body that extends into the battery cavity, and the air inlet is located inside the air guide sleeve.

12. The energy storage device according to claim 8, characterized in that, The valve is a phase change element made of a second shape memory alloy. The phase change element is connected to the inner wall surface of the second upper cover, and the air guide sleeve is connected to the inner wall surface of the first upper cover. Wherein, the length of the phase change element when it is in the closed state is L3, and it closes the first through hole; the length of the phase change element when it is in the open state is L4, and it opens the first through hole, where L3 > L4.

13. The energy storage device according to claim 12, characterized in that, The initial phase transition temperature of the second shape memory alloy is lower than that of the first shape memory alloy.

14. The energy storage device according to claim 12, characterized in that, The second shape memory alloy is a heat-shrinkable shape memory alloy.

15. An electrical appliance, characterized in that, The device includes the energy storage device according to any one of claims 1-14, wherein the energy storage device supplies power to the electrical equipment.

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