Energy storage device and energy storage system

Abstract

The utility model provides an energy storage device and an energy storage system. The energy storage device comprises a battery pack, a cabinet body and a second pressure relief mechanism. The battery pack comprises a box body, single batteries and a first pressure relief mechanism, the single batteries are contained in the box body, and the first pressure relief mechanism is arranged in the box body. The cabinet body is provided with a containing cavity, the battery pack is contained in the containing cavity, the cabinet body is provided with an exhaust channel, and the exhaust channel is communicated with the containing cavity. The second pressure relief mechanism is arranged on the cabinet body, and the exhaust channel is configured to guide emissions discharged by the first pressure relief mechanism to the second pressure relief mechanism so as to be discharged out of the cabinet body. According to the energy storage device provided by the invention, the content of pollutants in emissions discharged into the environment can be reduced, so that the pollution to the environment under the thermal runaway condition of the energy storage device can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more particularly, to an energy storage device and an energy storage system. Background Art

[0002] With the rapid development of technology, electric energy has become an indispensable energy source in people's production and life. In order to improve the smoothness of electric energy supply and ensure the normal operation of production and life, energy storage devices are required. As a device for storing electric energy, the energy storage device stores electric energy in the energy storage device by charging or discharging the energy storage device, or supplies the electric energy stored in the energy storage device to an electric device. Energy storage devices are widely used in fields such as industrial power supply, household power supply, temporary power supply, mobile power supply, wind power generation, solar power generation, and energy storage power stations.

[0003] During the operation of the energy storage device, there is a risk of thermal runaway. In the case of thermal runaway of the energy storage device, emissions will be released into the environment. How to reduce environmental pollution in the case of thermal runaway of the energy storage device is a continuously improving technical problem in energy storage technology. Summary of the Utility Model

[0004] The present application provides an energy storage device and an energy storage system to reduce environmental pollution in the case of thermal runaway of the energy storage device.

[0005] The present application is implemented by the following technical solutions:

[0006] In a first aspect, the energy storage device provided by the embodiments of the present application includes a battery pack, a cabinet, and a second pressure relief mechanism. The battery pack includes a box body, battery cells, and a first pressure relief mechanism. The battery cells are accommodated in the box body, and the first pressure relief mechanism is provided on the box body. The cabinet has a receiving cavity, the battery pack is accommodated in the receiving cavity, the cabinet has an exhaust passage, and the exhaust passage is communicated with the receiving cavity. The second pressure relief mechanism is provided on the cabinet, and the exhaust passage is configured to be able to guide the emissions discharged by the first pressure relief mechanism to the second pressure relief mechanism to discharge the cabinet.

[0007] For the energy storage device provided by the embodiments of the present application, by providing that the cabinet has an exhaust passage and the exhaust passage is communicated with the receiving cavity, in the case of thermal runaway of the energy storage device, the exhaust passage can guide the emissions discharged by the first pressure relief mechanism to the second pressure relief mechanism and discharge them to the outside of the cabinet through the second pressure relief mechanism. In this way, during the process of the emissions flowing through the exhaust passage, condensation, adsorption and other effects will occur in the exhaust passage, and at least part of the pollutants in the emissions will be deposited and retained in the exhaust passage. In this way, it is beneficial to reduce the content of pollutants in the emissions discharged into the environment, and thus it is beneficial to reduce environmental pollution in the case of thermal runaway of the energy storage device.

[0008] According to some embodiments of the present application, the accommodating cavity has a collection cavity, the collection cavity is a cavity body within the accommodating cavity, the exhaust passage is in communication with the collection cavity, and the volume V of the collection cavity satisfies: 300L ≤ V ≤ 10000L.

[0009] In the above solution, by setting 300L ≤ V ≤ 10000L, it is beneficial to reduce the risk that the emissions mix with the air in the collection cavity and then cause the failure of the cabinet seal. At the same time, it is also beneficial to increase the residence time of the emissions in the collection cavity, which is conducive to increasing the temperature drop of the emissions, and is beneficial to increasing the amount of emissions that condense in the collection cavity or the exhaust passage, and further beneficial to reducing the content of pollutants in the emissions discharged into the environment, and further reducing environmental pollution.

[0010] According to some embodiments of the present application, along the extending direction of the exhaust passage, the length of the shortest path of the exhaust passage is L1, and 2m ≤ L1 ≤ 600m.

[0011] In the above solution, by setting 2m ≤ L1 ≤ 600m, it is beneficial to improve the condensation efficiency of the cabinet in the exhaust passage while reducing the risk of cabinet seal failure, and further beneficial to increasing the content of pollutants in the emissions discharged into the environment in the case of thermal runaway of the energy storage device.

[0012] According to some embodiments of the present application, the energy density D of the battery cell satisfies: 300Wh / L ≤ D ≤ 550Wh / L, and 300L ≤ V ≤ 4000L, 2m ≤ L1 ≤ 150m.

[0013] In the above solution, for battery cells with an energy density D in the range of 300Wh / L ≤ D ≤ 550Wh / L, the chemical reaction during thermal runaway is relatively gentle. By setting 300L ≤ V ≤ 4000L, 2m ≤ L1 ≤ 150m, it is beneficial to improve the condensation efficiency of the emissions in the collection cavity and the exhaust passage to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection cavity and the exhaust passage, and beneficial to increasing the energy density of the energy storage device.

[0014] According to some embodiments of the present application, 300L ≤ V ≤ 1000L, 5m ≤ L1 ≤ 15m.

[0015] In the above solution, by setting 300L ≤ V ≤ 1000L, 5m ≤ L1 ≤ 15m, when the energy storage device is in thermal runaway, it is beneficial to further reduce the volume of the collection cavity and the exhaust passage on the premise of meeting the cooling and condensation requirements of the emissions, so as to further increase the energy density of the energy storage device.

[0016] According to some embodiments of the present application, the energy density D of the battery cell satisfies: 550 Wh / L < D ≤ 750 Wh / L, and 500 L ≤ V ≤ 8000 L, 5 m ≤ L1 ≤ 300 m.

[0017] In the above solution, for the battery cell with the energy density D in the range of 550 Wh / L < D ≤ 750 Wh / L, the chemical reaction under thermal runaway is relatively intense. By setting 500 L ≤ V ≤ 8000 L, 5 m ≤ L1 ≤ 300 m, it is beneficial to improve the condensation efficiency of the emissions in the collection chamber and the exhaust passage, so as to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection chamber and the exhaust passage, which is beneficial to improving the energy density of the energy storage device.

[0018] According to some embodiments of the present application, 500 L ≤ V ≤ 1200 L, 5 m ≤ L1 ≤ 15 m.

[0019] In the above solution, by setting 500 L ≤ V ≤ 1200 L, 5 m ≤ L1 ≤ 15 m, when the energy storage device is in thermal runaway, on the premise of meeting the cooling and condensation requirements of the emissions, it is beneficial to further reduce the volume of the collection chamber and the exhaust passage, so as to further improve the energy density of the energy storage device.

[0020] According to some embodiments of the present application, the energy density D of the battery cell satisfies: 750 Wh / L < D ≤ 900 Wh / L, and 800 L ≤ V ≤ 10000 L, 8 m ≤ L1 ≤ 600 m.

[0021] In the above solution, for the battery cell with the energy density D in the range of 750 Wh / L < D ≤ 900 Wh / L, the chemical reaction under thermal runaway is even more intense. By setting 800 L ≤ V ≤ 10000 L, 8 m ≤ L1 ≤ 600 m, it is beneficial to improve the condensation efficiency of the emissions in the collection chamber and the exhaust passage, so as to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection chamber and the exhaust passage, which is beneficial to improving the energy density of the energy storage device.

[0022] According to some embodiments of the present application, 800 L ≤ V ≤ 1500 L, 8 m ≤ L1 ≤ 20 m.

[0023] In the above solution, by setting 800 L ≤ V ≤ 1500 L, 8 m ≤ L1 ≤ 20 m, when the energy storage device is in thermal runaway, on the premise of meeting the cooling and condensation requirements of the emissions, it is beneficial to further reduce the volume of the collection chamber and the exhaust passage, so as to further improve the energy density of the energy storage device.

[0024] According to some embodiments of the present application, the exhaust passage has an inlet near one end of the accommodating cavity. The length of the shortest path from the first pressure relief mechanism to the inlet is L2, and 0.1m ≤ L2 ≤ 4m.

[0025] In the above solution, by setting 0.1m ≤ L2 ≤ 4m, in the case of thermal runaway of the energy storage device, it is beneficial to increase the residence time of the emissions in the accommodating cavity, improve the efficiency of cooling and condensing the emissions, and thereby reduce the content of pollutants in the emissions discharged outside the cabinet. At the same time, it can also reduce the risk of the cabinet seal failure caused by excessive pressure in the accommodating cavity.

[0026] According to some embodiments of the present application, the first pressure relief mechanism includes a first valve body and a first valve core. The first valve body is connected to the cabinet and has a first pressure relief passage. The first valve core is configured to be able to move axially along the first axial direction of the first pressure relief mechanism relative to the first valve body to block or open the first pressure relief passage. Under the pressure of 2Kpa - 20Kpa, along the first axial direction, the maximum stroke H1 of the first valve core relative to the first valve body along the first axial direction, and the perimeter of the outlet of the first pressure relief passage facing the first valve core is a1. The exhaust passage has an air inlet facing one end of the accommodating cavity, and the sum of the cross-sectional areas of the air inlets is S, and 0.1 ≤ a1·H1 / S ≤ 10.

[0027] In the above solution, by setting 0.1 ≤ a1·H1 / S ≤ 10, it is beneficial to increase the residence time of the emissions in the accommodating cavity, so as to more fully cool and condense the emissions, and at the same time, it is beneficial to reduce the rate of increase in pressure in the accommodating cavity, thereby reducing the risk of cabinet seal failure.

[0028] According to some embodiments of the present application, 0.5 ≤ a1·H1 / S ≤ 5.

[0029] In the above solution, by setting 0.5 ≤ a1·H1 / S ≤ 5, it is beneficial to further increase the residence time of the emissions in the accommodating cavity, so as to more fully cool and condense the emissions, and at the same time, it is further beneficial to reduce the rate of increase in pressure in the accommodating cavity, thereby reducing the risk of cabinet seal failure.

[0030] According to some embodiments of the present application, the second pressure relief mechanism includes a second valve body and a second valve core. The second valve body is connected to the cabinet and has a second pressure relief passage. The second valve core is configured to be able to move axially along the second axial direction of the second pressure relief passage relative to the second valve body to block or open the second pressure relief passage. Under the pressure of 2Kpa - 20Kpa, the maximum stroke H2 of the second valve core relative to the second valve body along the second axial direction satisfies: 0.1mm ≤ H2 ≤ 1mm.

[0031] In the above solution, by setting 0.1 mm ≤ H2 ≤ 1 mm, it is beneficial to reduce the risk of the cabinet seal failure caused by excessive air pressure in the accommodation cavity, and at the same time, it is convenient for the emissions to be sufficiently cooled and condensed in the accommodation cavity and the exhaust passage, further reducing the content of pollutants in the emissions discharged outside the cabinet.

[0032] According to some embodiments of the present application, the perimeter of the outlet at one end of the second pressure relief passage facing the second valve element is a2, satisfying: 10 mm 2 ≤ a2·H2 ≤ 150 mm 2 .

[0033] In the above solution, by setting 10 mm 2 ≤ a2·H2 ≤ 150 mm 2 , it is beneficial to increase the retention time of the emissions in the accommodation cavity to facilitate more sufficient cooling and condensation of the emissions, and at the same time, it is beneficial to reduce the rate of increase in the pressure in the accommodation cavity, thereby reducing the risk of the cabinet seal failure.

[0034] According to some embodiments of the present application, the melting point T of the wall of the exhaust passage satisfies: T ≥ 80 °C.

[0035] In the above solution, by setting the melting point T of the wall of the exhaust passage to satisfy: T ≥ 80 °C, it is beneficial to reduce the risk of the wall of the exhaust passage melting in the case of thermal runaway of the energy storage device, thereby reducing the risk of the exhaust passage seal failure, and reducing the risk of the emissions being directly discharged outside the cabinet through the discharge passage.

[0036] According to some embodiments of the present application, the energy storage device includes a plurality of second pressure relief mechanisms and a plurality of exhaust passages, and at least one exhaust passage is configured to be able to guide the emissions to any one of the second pressure relief mechanisms.

[0037] In the above solution, by setting the energy storage device to include a plurality of second pressure relief structures and exhaust passages, in the case of thermal runaway of the energy storage device, the emissions can be discharged through the plurality of exhaust passages and the plurality of second pressure relief mechanisms, which is beneficial to improving the timeliness of the emissions discharge and reducing the risk of explosion of the energy storage device due to thermal runaway.

[0038] According to some embodiments of the present application, at least one bend is provided in the exhaust passage.

[0039] In the above solution, when the emissions flow through the bend of the exhaust passage, they will collide with the inner wall of the exhaust passage, and particles or droplets therein will be blocked by the exhaust passage and condensed and settled, and finally remain in the exhaust passage. Thus, it is beneficial to further reduce the content of pollutants in the emissions discharged into the environment.

[0040] According to some embodiments of the present application, the exhaust passage includes a pipe, and the pipe is connected to the cabinet body.

[0041] In the above solution, by connecting the pipe to the cabinet body, it is beneficial to improve the matching strength between the pipe and the cabinet body, making the structure of the exhaust passage more stable and reliable, and facilitating the exhaust passage to cope with more complex working conditions of the energy storage device.

[0042] In a second aspect, the energy storage system provided by the embodiments of the present application includes the energy storage device provided by any one of the above embodiments.

[0043] Since the energy storage system provided by the embodiments of the present application adopts the energy storage device provided by the above embodiments, it has the same technical effects, which will not be elaborated here.

[0044] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1 It is a schematic structural diagram of the energy storage system provided by the embodiments of the present application;

[0047] Figure 2 It is a schematic structural diagram of an energy storage device provided by the embodiments of the present application;

[0048] Figure 3 It is a schematic structural diagram of a battery pack in the energy storage device provided by the embodiments of the present application;

[0049] Figure 4 It is a schematic explosion structure diagram of a battery cell in the energy storage device provided by the embodiments of the present application;

[0050] Figure 5 It is another schematic structural diagram of the energy storage device provided by the embodiments of the present application;

[0051] Figure 6 It is a schematic cross-sectional structure diagram of a first pressure relief mechanism in the energy storage device provided by the embodiments of the present application;

[0052] Figure 7 It is a schematic cross-sectional structure diagram of a second pressure relief mechanism in the energy storage device provided by the embodiments of the present application.

[0053] In the accompanying drawings, the drawings are not necessarily drawn to scale.

[0054] Description of reference numerals in the drawings:

[0055] 1 - Energy storage system;

[0056] 10 - Energy storage device; 11 - Cabinet; 11a - Accommodating cavity; 111a - Collection cavity; 11b - Exhaust passage; 111b - Pipe;

[0057] 20 - Battery pack; 21 - Box body; 22 - First pressure relief mechanism; 22a - First pressure relief passage; 221 - First valve body; 222 - First valve core;

[0058] 30 - Battery cell; 31 - Outer shell; 311 - Shell; 312 - End cover; 32 - Electrode assembly; 33 - Electrode terminal;

[0059] 40 - Second pressure relief mechanism; 41 - Second valve body; 42 - Second valve core; 40a - Second pressure relief passage;

[0060] X - First axial direction; Y - Second axial direction. Detailed implementation manners

[0061] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs; the terms used in the description of the present application in the specification of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non - exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific order or primary - secondary relationship.

[0063] Reference to "embodiment" in this application means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application may be combined with other embodiments.

[0064] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected", "attached" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0065] The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0066] The "plurality" mentioned in this application refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0067] The embodiment of this application provides an energy storage device, including one or more battery packs to increase the voltage and capacity of the energy storage device. One or more battery packs are accommodated in a cabinet, and the multiple battery packs can be connected in series and / or in parallel.

[0068] In some embodiments, the energy storage device includes an energy storage container, an energy storage electrical cabinet, etc. The battery packs mentioned in the embodiments of this application may include one or more battery cell components for providing voltage and capacity. The battery cell components may include multiple battery cells, and the multiple battery cells are connected in series, in parallel or in a hybrid connection through a busbar.

[0069] In some embodiments, the battery cell components are usually formed by arranging multiple battery cells; as an example, the battery cell components may be battery modules, and the battery modules are formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery modules can be formed by bundling multiple battery cells with cable ties.

[0070] In the embodiment of this application, the battery cell can be a secondary battery, and a secondary battery refers to a battery cell that can be activated by charging after the battery cell discharges and can be used continuously.

[0071] The battery cell can be, but is not limited to, a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0072] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and allow the active ions to pass through at the same time.

[0073] In some embodiments, the positive electrode can be a positive electrode sheet, and the positive electrode sheet can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0074] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0075] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0076] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as the positive electrode active material of the battery cell can also be used.

[0077] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0078] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. can be used.

[0079] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0080] As an example, the negative electrode active material can be the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based materials can be selected from at least one of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based materials can be selected from at least one of elemental tin, tin oxides, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as the negative electrode active material of battery cells can also be used. These negative electrode active materials can be used alone, or two or more of them can be used in combination.

[0081] In some embodiments, the separator is an insulating film. The present application does not particularly limit the type of the insulating film, and any well-known porous structure insulating film with good chemical stability and mechanical stability can be selected.

[0082] As an example, the main material of the insulating film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The insulating film can be a single-layer film or a multi-layer composite film, without particular limitation. When the insulating film is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or can be attached to the surfaces of the positive and negative electrodes.

[0083] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0084] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0085] In some embodiments, the electrode assembly is a stacked structure.

[0086] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0087] In some embodiments, the housing includes an end cap and a housing body. The housing body is provided with an opening, and the end cap closes the opening to form a sealed space for accommodating components such as the electrode assembly and the electrolyte. The housing body can be provided with one or more openings. The end cap can also be provided with one or more.

[0088] In some embodiments, at least one electrode terminal is provided on the outer casing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0089] In some embodiments, an explosion-proof valve is provided on the outer casing. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0090] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal-prismatic battery, etc. There is no particular limitation in the embodiments of the present application.

[0091] An energy storage device generally includes battery cells, and the battery cells are cyclically charged and discharged to store and utilize electric energy. When the battery cells of the energy storage device are in a thermal runaway state, the internal pressure and temperature of the battery cells will increase, causing the pressure relief mechanism of the battery cells to open and release the pressure. As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal-prismatic battery, etc. There is no particular limitation in the embodiments of the present application.

[0092] The energy storage device can include a battery pack and a cabinet. The battery pack includes a box body and a plurality of battery cells. The first pressure relief mechanism is provided on the box body, and the battery pack is accommodated in the cabinet. The second pressure relief mechanism of the energy storage device is provided on the cabinet. When the energy storage device is in a thermal runaway state, the high-pressure emissions released by the battery cells are discharged into the accommodation cavity of the cabinet through the first pressure relief mechanism. The emissions usually contain substances such as the electrolyte of the battery cells, and the emissions usually contain more pollutants.

[0093] In the related art, when the energy storage device is in a thermal runaway state, when the pressure of the emissions in the accommodation cavity reaches the threshold of the second pressure relief mechanism, the emissions are directly discharged into the environment through the second pressure relief mechanism. In this way, it will cause certain pollution to the environment.

[0094] In view of this, the energy storage device provided in the embodiments of the present application includes a battery pack, a cabinet and a second pressure relief mechanism. The battery pack includes a box body, battery cells and a first pressure relief mechanism. The battery cells are accommodated in the box body, and the first pressure relief mechanism is provided on the box body. The cabinet has an accommodation cavity, the battery pack is accommodated in the accommodation cavity, and the cabinet has an exhaust passage, and the exhaust passage is communicated with the accommodation cavity. The second pressure relief mechanism is provided on the cabinet, and the exhaust passage is configured to be able to guide the emissions released by the first pressure relief mechanism to the second pressure relief mechanism to discharge the cabinet.

[0095] The energy storage device provided by the embodiment of the present application is provided with an exhaust passage in the cabinet body and the exhaust passage is communicated with the accommodation cavity, so that in the case of thermal runaway of the energy storage device, the exhaust passage can guide the emissions discharged by the first pressure relief mechanism to the second pressure relief mechanism and discharge them to the outside of the cabinet body through the second pressure relief mechanism. In this way, during the process of the emissions flowing through the exhaust passage, condensation, adsorption and other effects will occur in the exhaust passage, and at least part of the pollutants in the emissions will be deposited and retained in the exhaust passage. In this way, it is beneficial to reduce the pollutant content in the emissions discharged into the environment, and thus beneficial to reduce the pollution to the environment in the case of thermal runaway of the energy storage device.

[0096] The technical solution described in the embodiment of the present application is applicable to the energy storage device and the electrical device using the energy storage device.

[0097] As Figure 1 shown is a schematic structural diagram of the energy storage system 1 provided by the embodiment of the present application. The energy storage system 1 can be an energy storage power station, a wind power generation system, a solar power generation system, a mobile power system or a temporary power supply system, etc. The energy storage power station can store electric energy during the low electricity consumption period and provide electric energy for relevant users or electrical equipment during the high electricity consumption period. After the wind energy collected by the wind turbine of the wind power generation system is converted into electric energy, it is stored by the energy storage device 10. The solar power generation system can convert solar energy into electric energy and store it by the energy storage device 10 and supply it to users in a timely manner. The mobile power system can supply power to relevant electrical equipment in places where the grid power supply system cannot reach, such as remote mountainous areas, remote wild areas, etc. The temporary power supply system can supply power to users in the case of insufficient power supply. The energy storage system 1 provided by the embodiment of the present application can be any power system that needs to use the energy storage device 10.

[0098] As Figure 2 shown is a schematic structural diagram of the energy storage device 10 provided by the embodiment of the present application. The energy storage device 10 can include a plurality of battery packs 20. As Figure 3 shown, the battery pack 20 can include a plurality of battery cells 30. The plurality of battery packs 20 can be connected in series, parallel or in a hybrid connection, and the plurality of battery cells 30 in one battery pack 20 can be connected in series, parallel or in a hybrid connection.

[0099] Please refer to Figure 4 , Figure 4 which is an explosion structural diagram of the battery cell 30 in the energy storage device 10 provided by the embodiment of the present application. As Figure 4 shown, the battery cell 30 includes a housing 31, an electrode assembly 32 and an electrode terminal 33. The housing 31 includes a housing body 311 and an end cover 312. The housing body 311 has an opening, and the end cover 312 closes the opening to isolate the internal environment of the battery cell 30 from the external environment.

[0100] The housing 311 is a component for cooperating with the end cap 312 to form the internal environment of the battery cell 30, wherein the formed internal environment can be used to accommodate the electrode assembly 32, the electrolyte, and other components. The housing 311 and the end cap 312 can be separate components. The housing 311 can be of various shapes and sizes. Specifically, the shape of the housing 311 can be determined according to the specific shape and size of the electrode assembly 32. The material of the housing 311 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0101] The end cap 312 refers to a component that covers the opening of the housing 311 to isolate the internal environment of the battery cell 30 from the external environment.

[0102] In some embodiments, a second pressure relief mechanism 40 is provided on the cabinet body 11, and the second pressure relief mechanism 40 is used to relieve the internal pressure of the cabinet body 11.

[0103] As an example, it is actuated when the internal pressure or temperature of the cabinet body 11 reaches a predetermined threshold to relieve the internal pressure or temperature. When the internal pressure or temperature of the cabinet body 11 reaches a predetermined threshold, the second pressure relief mechanism 40 performs an action or a weak structure provided in the second pressure relief mechanism 40 is damaged, thereby forming an opening or a channel for the internal pressure or temperature to be relieved. This threshold design varies according to different design requirements.

[0104] As an example, the second pressure relief mechanism 40 can be integrally formed with the cabinet body 11. For example, a notch is formed on the cabinet body 11 to form a weak structure, and this weak structure serves as the second pressure relief mechanism 40.

[0105] The second pressure relief mechanism 40 can also be separately provided and connected to the cabinet body 11. For example, the second pressure relief mechanism 40 is welded to the cabinet body 11 or connected through other components. As an example, a notch is provided on the second pressure relief mechanism 40 to form a weak structure.

[0106] As an example, the second pressure relief mechanism 40 can be in the form of, such as, an explosion-proof valve, a balance valve, a gas valve, a pressure relief valve, or a safety valve, etc.

[0107] The "actuation" mentioned in this application means that the second pressure relief mechanism 40 generates an action or is activated to a certain state, so that the internal pressure and temperature of the cabinet body 11 can be relieved. The actions generated by the second pressure relief mechanism 40 can include, but are not limited to: the components in the second pressure relief mechanism 40 move to form an exhaust flow channel, at least a part of the second pressure relief mechanism 40 breaks, shatters, is torn, or opens, etc. When the second pressure relief mechanism 40 is actuated, the high-temperature and high-pressure substances inside the cabinet body 11 will be discharged outward from the actuated part as emissions. In this way, the energy storage device 10 can be depressurized and cooled under a controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0108] It is understandable that the first pressure relief mechanism 22 is provided in the box body 21. The emissions discharged from the battery cell 30 are first discharged into the box body 21. When the pressure in the box body 21 reaches the actuation threshold of the first pressure relief mechanism 22, the first pressure relief mechanism 22 actuates and discharges the emissions into the cabinet body 11.

[0109] The structural type of the first pressure relief mechanism 22 can be the same as or different from that of the second pressure relief mechanism 40.

[0110] The emissions from the battery cell 30 mentioned in this application include but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, and so on.

[0111] In a first aspect, as Figure 2 、 Figure 3 and Figure 4 shown, the energy storage device 10 includes a battery pack 20, a cabinet body 11, and a second pressure relief mechanism 40. The battery pack 20 includes a box body 21, battery cells 30, and a first pressure relief mechanism 22. The battery cells 30 are accommodated in the box body 21, and the first pressure relief mechanism 22 is provided in the box body 21. The cabinet body 11 has a receiving cavity 11a, the battery pack 20 is accommodated in the receiving cavity 11a, and the cabinet body 11 has an exhaust passage 11b, and the exhaust passage 11b is communicated with the receiving cavity 11a. The second pressure relief mechanism 40 is provided in the cabinet body 11, and the exhaust passage 11b is configured to be able to guide the emissions discharged by the first pressure relief mechanism 22 to the second pressure relief mechanism 40 to discharge the cabinet body 11.

[0112] The battery pack 20 may include a plurality of battery cells 30. The plurality of battery cells 30 are accommodated in the box body 21. The box body 21 may be hermetically arranged, and the first pressure relief mechanism 22 is provided in the box body 21.

[0113] In the case of thermal runaway of the energy storage device 10, the emissions discharged from the battery cell 30 are first discharged into the box body 21. As the thermal runaway of the battery cell 30 further develops, the emissions in the box body 21 gradually increase, and the air pressure gradually rises. When the pressure in the box body 21 reaches the actuation threshold of the first pressure relief mechanism 22, the first pressure relief mechanism 22 actuates and discharges the emissions into the receiving cavity 11a of the cabinet body 11.

[0114] Before the air pressure in the cabinet body 11 reaches the actuation threshold of the second pressure relief mechanism 40, the emissions are preliminarily cooled and condensed in the receiving cavity 11a of the cabinet body 11, and part of the emissions will be deposited and remain in the cabinet body 11. As the thermal runaway of the energy storage device 10 further develops, more and more emissions are discharged into the receiving cavity 11a.

[0115] Since the accommodation cavity 11a is in communication with the exhaust passage 11b, the pressure in the accommodation cavity 11a can act on the second pressure relief mechanism 40 via the exhaust passage 11b. As the air pressure in the accommodation cavity 11a further increases, when the air pressure in the accommodation cavity 11a reaches the actuation threshold of the second pressure relief mechanism 40, the second pressure relief mechanism 40 is actuated, and the emissions in the accommodation cavity 11a flow to the second pressure relief structure via the exhaust passage 11b.

[0116] During the process of the emissions flowing through the exhaust passage 11b, the temperature of the emissions in the exhaust passage 11b is reduced again, and at least part of the emissions undergoes condensation or adsorption in the exhaust passage 11b. Thus, at least part of the pollutants in the emissions are deposited and retained in the exhaust passage 11b, and the content of pollutants in the emissions discharged to the outside of the cabinet 11 via the second pressure relief mechanism 40 is reduced, which is conducive to reducing the content of pollutants in the emissions discharged to the outside of the cabinet 11.

[0117] The cabinet 11 has an exhaust passage 11b, and the exhaust passage 11b is configured to be able to guide the emissions discharged by the first pressure relief mechanism 22 to the second pressure relief mechanism 40. Then, the exhaust passage 11b can be on the path from the first pressure relief mechanism 22 to the second pressure relief mechanism 40. Optionally, the exhaust passage 11b can be located inside the frame of the cabinet 11, etc., or the exhaust passage 11b can be located in the accommodation cavity 11a. Of course, part of the exhaust passage 11b can also be located in the accommodation cavity 11a, and the other part can be located inside the frame of the cabinet 11. Or, as Figure 5 shown, at least part of the exhaust passage 11b can also be provided outside the cabinet 11.

[0118] Optionally, the cabinet 11 can have one exhaust passage 11b, or the cabinet 11 can be provided with multiple exhaust passages 11b. Different exhaust passages 11b can have the same inlet communicating with the accommodation cavity 11a, or different exhaust passages 11b can be provided with different inlets communicating with the accommodation cavity 11a. Different exhaust passages 11b can be completely non-overlapping, or part of different exhaust passages 11b can be overlapped.

[0119] An energy storage device 10 can have one, two or more second pressure relief mechanisms 40, and any one of the second pressure relief mechanisms 40 can be in communication with the accommodation cavity 11a through at least one exhaust passage 11b. Different pressure relief mechanisms can be provided on different walls of the cabinet 11 and have the same or different actuation thresholds.

[0120] The energy storage device 10 provided by the embodiment of the present application is configured such that the cabinet 11 has an exhaust passage 11b, and the exhaust passage 11b is communicated with the accommodation cavity 11a. In the case of thermal runaway of the energy storage device 10, the exhaust passage 11b can guide the emissions discharged by the first pressure relief mechanism 22 to the second pressure relief mechanism 40 and discharge them to the outside of the cabinet 11 through the second pressure relief mechanism 40. In this way, during the process of the emissions flowing through the exhaust passage 11b, condensation, adsorption and other effects will occur in the exhaust passage 11b, and at least part of the pollutants in the emissions will be deposited and retained in the exhaust passage 11b. In this way, it is beneficial to reduce the pollutant content in the emissions discharged into the environment, and thus beneficial to reduce the pollution to the environment in the case of thermal runaway of the energy storage device 10.

[0121] In some embodiments, as Figure 2 and Figure 5 shown, the accommodation cavity 11a has a collection cavity 111a. The collection cavity 111a is a hollow cavity within the accommodation cavity 11a. The exhaust passage 11b is communicated with the collection cavity 111a, and the volume V of the collection cavity 111a satisfies: 300L ≤ V ≤ 10000L.

[0122] It can be understood that in addition to accommodating the battery pack 20, the accommodation cavity 11a of the cabinet 11 also accommodates some electrical components, such as a main control box, etc. In addition, some water cooling units, etc. are also accommodated. Since the collection cavity 111a is a hollow cavity within the accommodation cavity 11a, the collection cavity 111a is the space within the accommodation cavity 11a that is not occupied by any fixed objects.

[0123] The battery pack 20, the water cooling unit and the main control box occupy a relatively large space in the accommodation cavity 11a. In addition, there are also some components whose volumes are not easy to calculate. According to experience, the calculation method of V in the present application is to multiply the volume of the accommodation cavity 11a minus the volumes of the battery pack 20, the water cooling unit and the main control box by a coefficient less than 1. Specifically, V = (V0 - n·V1 - m·V2 - V3)·0.88, where V0 is the total volume of the accommodation cavity 11a, V1 is the volume of a single battery pack 20, n is the number of battery packs 20 in the accommodation cavity 11a, V2 is the volume of a single main control cavity, m is the number of main control boxes in the accommodation cavity 11a, and V3 is the volume of the water cooling unit.

[0124] Optionally, V can be 300L, 350L, 400L, 450L, 500L, 550L, 600L, 650L, 700L, 750L, 800L, 850L, 900L, 950L, 1000L, 1500L, 2000L, 2500L, 3000L, 3500L, 4000L, 4500L, 5000L, 5500L, 6000L, 6500L, 7000L, 7500L, 8000L, 8500L, 9000L, 9500L or 10000L, etc.

[0125] It can be understood that in the case of thermal runaway of the energy storage device 10, the emissions will first be discharged into the collection chamber 111a and stay in the collection chamber 111a for a period of time to obtain preliminary cooling. Therefore, the larger the value of V, the more conducive it is to increasing the residence time of the emissions in the collection chamber 111a, so that the emissions can be fully cooled in the collection chamber 111a, improving the condensation efficiency of the emissions, and further increasing the amount of emissions deposited and retained in the cabinet 11, which is beneficial to reducing the content of pollutants discharged into the environment. On the contrary, the smaller the value of V, the smaller the amount of air contained in the collection chamber 111a, which is more conducive to reducing the risk of explosion when the high-temperature emissions mix with the air in the collection chamber 111a, and then causing the sealing interface of the cabinet 11 to fail.

[0126] Therefore, the inventor conducted a series of tests. In the tests, only the value of V of different energy storage devices 10 was changed, while other parameters were the same, in order to obtain the influence of different V values on the temperature of the discharged emissions. The test results are shown in Table 1.

[0127] Table 1 Influence of V of the energy storage device 10 on the emissions in the case of thermal runaway

[0128]

[0129] As can be seen from Table 1 above, in the comparative example where V is less than 300L, the temperature of the discharged emissions is relatively high, which is not conducive to the condensation of the emissions in the exhaust passage 11b. In the comparative example where V is greater than 10000L, the high-temperature emissions burn after mixing with the emissions in the collection chamber 111a, resulting in the sealing failure of the cabinet 11.

[0130] Therefore, after systematic analysis and long-term practice, the inventor found that by setting 300L ≤ V ≤ 10000L, it is beneficial to reduce the risk of the emission mixture with the air in the collection chamber 111a and then causing the sealing failure of the cabinet 11. At the same time, it is also beneficial to increase the residence time of the emissions in the collection chamber 111a, thereby facilitating the increase in the temperature drop of the emissions, increasing the amount of condensed emissions in the collection chamber 111a or the exhaust passage 11b, and further reducing the content of pollutants in the emissions discharged into the environment, further reducing environmental pollution.

[0131] In some embodiments, along the extending direction of the exhaust passage 11b, the length of the shortest path of the exhaust passage 11b is L1, and 2m ≤ L1 ≤ 600m.

[0132] It can be understood that the exhaust passage 11b may have multiple air inlets. Correspondingly, the exhaust passage 11b may have multiple paths with different lengths, and L1 is the shortest exhaust path corresponding to the exhaust passage 11b.

[0133] Optionally, L1 may be 2m, 10m, 50m, 60m, 80m, 100m, 150m, 200m, 250m, 300m, 350m, 400m, 450m, 500m, 550m or 600m, etc.

[0134] The measurement method of the shortest length L of the path of the exhaust passage 11b may be to measure the total length of the pipeline from the inlet to the outlet of the exhaust passage 11b. In the case where the exhaust passage 11b has multiple sections, the lengths of different sections can be measured separately and then added up to obtain the total length of the exhaust passage 11b.

[0135] Alternatively, the wire threading method can also be used. Thread a measuring wire, etc. into the exhaust passage 11b from the inlet, and thread it out from the outlet of the exhaust passage 11b along the shortest path of the exhaust passage 11b. The length of the wire from the inlet to the outlet is measured as the length of the exhaust passage 11b.

[0136] It can be understood that the longer L1 is, the larger the contact area between the emissions and the inner wall of the exhaust passage 11b is, and the higher the condensation efficiency of the emissions in the exhaust passage 11b is. And the shorter L1 is, the more beneficial it is for the emissions to be discharged in time, reducing the risk of the sealing failure of the cabinet 11 caused by excessive air pressure in the exhaust passage 11b.

[0137] Therefore, the inventor conducted a series of experiments. For different energy storage devices 10, only changing the shortest path L1 of the exhaust passage 11b while keeping other parameters unchanged, as shown in Table 2 below.

[0138] Table 2 Influence of the length L1 of the exhaust passage 11b on the emissions of the energy storage device 10 during thermal runaway

[0139]

[0140] As can be seen from Table 2 above, in the comparative examples where L1 is less than 2m, the temperature of the discharged emissions is relatively high, which is not conducive to the full condensation of the emissions in the exhaust passage 11b. In the comparative examples where L1 is greater than 600m, the sealing interface of the cabinet 11 fails, and the emissions can be directly discharged through the failed sealing interface without being condensed. In the examples where L1 is between 1m and 600m, the temperature of the discharged emissions is relatively low, and the sealing of the cabinet 11 is intact.

[0141] Therefore, after systematic analysis and long-term practice, the inventors found that by setting 2m ≤ L1 ≤ 600m, it is beneficial to improve the condensation efficiency of the cabinet 11 in the exhaust passage 11b, and at the same time, it is beneficial to reduce the risk of sealing failure of the cabinet 11, and further beneficial to increase the content of pollutants in the emissions discharged into the environment under thermal runaway of the energy storage device 10.

[0142] In some embodiments, the energy density D of the battery cell 30 satisfies: 300 Wh / L ≤ D ≤ 550 Wh / L, and 300 L ≤ V ≤ 4000 L, 2m ≤ L1 ≤ 150m.

[0143] The energy density of the battery cell 30 is 300 Wh / L ≤ D ≤ 550 Wh / L. Optionally, the battery cell 30 can be a lithium iron phosphate battery cell, or the battery cell 30 can be a smaller ternary battery cell.

[0144] It can be understood that when the energy density of the battery cell 30 is relatively low, the reaction inside the battery cell 30 under thermal runaway of the energy storage device 10 is relatively gentle, and the amount and discharge rate of the discharged emissions are relatively low. Therefore, the volume of the collection chamber 111a and the length L1 of the shortest path of the exhaust passage 11b required are also relatively short, so as to reduce the volume occupied by the collection chamber 111a and the exhaust passage 11b while meeting the cooling requirements of the emissions, and improve the energy density of the energy storage device 10.

[0145] When the energy density D of the battery cell 30 satisfies 300 Wh / L ≤ D ≤ 550 Wh / L, optionally, V can be 300L, 350L, 400L, 450L, 500L, 550L, 600L, 650L, 700L, 750L, 800L, 850L, 900L, 950L, 1000L, 1500L, 2000L, 2500L, 3000L, 3500L or 4000L, etc., and L1 can be 2m, 10m, 50m, 60m, 80m, 100m or 150m, etc.

[0146] To this end, the inventors conducted a series of tests. For the energy storage device 10 with an energy density in the range of 300 Wh / L ≤ D ≤ 550 Wh / L, only the V and L1 of the energy storage device 10 in different embodiments and comparative examples were changed. When the energy storage device 10 was in thermal runaway, the temperature of the discharged emissions was obtained, and the results are shown in Table 3.

[0147] Table 3 Effects of V and L1 of the energy storage device 10 on emissions in the case of thermal runaway

[0148]

[0149] As can be seen from Table 3 above, for the battery cell 30 with an energy density D in the range of 300 Wh / L ≤ D ≤ 550 Wh / L, in the comparative examples where V is less than 300 L and L1 is less than 2 m, the temperature of the emissions discharged in the case of thermal runaway of the energy storage device 10 is relatively high, which is not conducive to the condensation of emissions in the collection chamber 111a and the exhaust passage 11b. In the comparative examples where V is greater than 4000 L and L1 is greater than 150 m, the sealing interface of the cabinet 11 fails. It can be seen that the residence time of the emissions in the collection chamber 111a and the exhaust passage 11b is too long and cannot be discharged in time.

[0150] After systematic analysis and long-term practice, the inventors found that for the battery cell 30 with an energy density D in the range of 300 Wh / L ≤ D ≤ 550 Wh / L, the chemical reaction in the case of thermal runaway is relatively gentle. By setting 300 L ≤ V ≤ 4000 L and 2 m ≤ L1 ≤ 150 m, it is beneficial to improve the condensation efficiency of emissions in the collection chamber 111a and the exhaust passage 11b, so as to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection chamber 111a and the exhaust passage 11b, which is beneficial to improving the energy density of the energy storage device 10 and facilitating the timely discharge of emissions, and reducing the risk of sealing failure of the cabinet 11.

[0151] In some embodiments, 300 L ≤ V ≤ 1000 L and 5 m ≤ L1 ≤ 15 m.

[0152] Optionally, V can be 300 L, 350 L, 400 L, 450 L, 500 L, 550 L, 600 L, 650 L, 700 L, 750 L, 800 L, 850 L, 900 L, 950 L or 1000 L, etc., and L1 can be 5 m, 6 m, 7 m, 8 m, 8 m, 10 m, 11 m, 12 m, 13 m, 14 m or 15 m, etc.

[0153] After further systematic analysis and long-term practice, the inventor found that by setting 300L ≤ V ≤ 1000L and 5m ≤ L1 ≤ 15m, when the energy storage device 10 is in thermal runaway, it is beneficial to further reduce the volumes of the collection chamber 111a and the exhaust passage 11b on the premise of meeting the cooling and condensation requirements of the emissions, so as to further improve the energy density of the energy storage device 10 and further facilitate the timely discharge of the cabinet, reducing the risk of seal failure of the cabinet 11.

[0154] In some embodiments, the energy density D of the battery cell 30 satisfies: 550 Wh / L < D ≤ 750 Wh / L, and 500L ≤ V ≤ 8000L, 5m ≤ L1 ≤ 300m.

[0155] Optionally, the battery cell 30 can be a ternary battery cell 30 or the like.

[0156] Compared with the battery cell 30 with 300 Wh / L ≤ D ≤ 550 Wh / L, for the battery cell 30 with an energy density of 550 Wh / L < D ≤ 750 Wh / L, the energy density of the battery cell 30 is further improved. When the energy storage device 10 is in thermal runaway, the chemical reaction inside the battery cell 30 is relatively intense, so the amount and rate of the emissions released by the battery cell 30 are relatively high, and a larger volume of the collection chamber 111a and a longer length of the exhaust passage 11b are required to sufficiently cool the emissions and improve the condensation efficiency of the emissions before they are discharged through the second pressure relief mechanism 40.

[0157] When the energy density D of the battery cell 30 satisfies 550 Wh / L ≤ D ≤ 750 Wh / L, optionally, V can be 500L, 550L, 600L, 650L, 700L, 750L, 800L, 850L, 900L, 950L, 1000L, 1500L, 2000L, 2500L, 3000L, 3500L, 4000L, 4500L, 5000L, 5500L, 6000L, 6500L, 7000L, 7500L or 8000L, etc., and L1 can be 5m, 10m, 50m, 60m, 80m, 100m, 150m, 200m, 250m or 300m, etc.

[0158] Therefore, the inventor conducted a series of tests. For the energy storage device 10 with an energy density in the range of 550 Wh / L < D ≤ 750 Wh / L, only the V and L1 of the energy storage device 10 in different embodiments and comparative examples were changed, and the temperature of the discharged emissions was obtained when the energy storage device 10 was in thermal runaway. The results are shown in Table 4.

[0159] Table 4 Influence of V and L1 of the energy storage device 10 on emissions in thermal runaway

[0160]

[0161] As can be seen from Table 4 above, for the battery cell 30 with the energy density D in the range of 550 Wh / L < D ≤ 750 Wh / L, in the comparative example where V is less than 500 L and L1 is less than 5 m, the temperature of the emissions discharged during the thermal runaway of the energy storage device 10 is relatively high, which is not conducive to the condensation of the emissions in the collection chamber 111a and the exhaust passage 11b. In the comparative example where V is greater than 8000 L and L1 is greater than 300 m, the sealing interface of the cabinet 11 fails. It can be seen that the residence time of the emissions in the collection chamber 111a and the exhaust passage 11b is too long and cannot be discharged in time.

[0162] After systematic analysis and long-term practice, the inventors found that for the battery cell 30 with the energy density D in the range of 550 Wh / L < D ≤ 750 Wh / L, the chemical reaction during its thermal runaway is relatively intense. By setting 500 L ≤ V ≤ 8000 L and 5 m ≤ L1 ≤ 300 m, it is beneficial to improve the condensation efficiency of the emissions in the collection chamber 111a and the exhaust passage 11b, so as to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection chamber 111a and the exhaust passage 11b, improve the energy density of the energy storage device 10, facilitate the timely discharge of the emissions, and reduce the risk of sealing failure of the cabinet 11.

[0163] In some embodiments, 500 L ≤ V ≤ 1200 L and 5 m ≤ L1 ≤ 15 m.

[0164] Optionally, V can be 500 L, 550 L, 600 L, 650 L, 700 L, 750 L, 800 L, 850 L, 900 L, 950 L, 1000 L or 1200 L, etc. L1 can be 5 m, 6 m, 7 m, 8 m, 9 m, 10 m, 11 m, 12 m, 13 m, 14 m or 15 m, etc.

[0165] After further systematic analysis and practice, the inventors found that by setting 500 L ≤ V ≤ 1200 L and 5 m ≤ L1 ≤ 15 m, when the energy storage device 10 is in thermal runaway, on the premise of meeting the cooling and condensation requirements of the emissions, it is beneficial to further reduce the volume of the collection chamber 111a and the exhaust passage 11b, so as to further improve the energy density of the energy storage device 10, further facilitate the timely discharge of the emissions, and reduce the risk of sealing failure of the cabinet 11.

[0166] In some embodiments, the energy density D of the battery cell 30 satisfies: 750 Wh / L < D ≤ 900 Wh / L, and 800 L ≤ V ≤ 10000 L, 8 m ≤ L1 ≤ 600 m.

[0167] Optionally, the battery cell 30 can be a sodium-ion battery cell 30, an alkali metal battery, etc. The sodium-ion battery cell 30 realizes the process of storing and releasing electrical energy of the battery cell 30 through the repeated migration of sodium ions between the positive electrode plate and the negative electrode plate. The negative electrode plate of the alkali metal battery includes a metal element. Exemplarily, for the lithium-ion battery cell 30, its negative electrode plate includes lithium metal, and for the sodium-ion battery cell 30, its negative electrode plate includes sodium metal.

[0168] Compared with the battery cell 30 with 550 Wh / L < D ≤ 750 Wh / L, for the battery cell 30 with an energy density of 750 Wh / L < D ≤ 900 Wh / L, the energy density of the battery cell 30 is further improved. In the case of thermal runaway of the energy storage device 10, the chemical reaction inside the battery cell 30 is more intense, so the amount and rate of the emissions released by the battery cell 30 are higher, and a larger volume of the collection chamber 111a and a longer length of the exhaust passage 11b are required to sufficiently cool the emissions and improve the condensation efficiency of the emissions before they are discharged through the second pressure relief mechanism 40.

[0169] Optionally, V can be 800 L, 850 L, 900 L, 950 L, 1000 L, 1500 L, 2000 L, 2500 L, 3000 L, 3500 L, 4000 L, 4500 L, 5000 L, 5500 L, 6000 L, 6500 L, 7000 L, 7500 L, 8000 L, 8500 L, 9000 L, 9500 L or 10000 L, etc., and L1 can be 8 m, 10 m, 20 m, 30 mm, 40 m, 50 m, 60 m, 70 m, 80 m, 90 m, 100 m, 150 m, 200 m, 250 m, 300 m, 350 m, 400 m, 450 m, 500 m, 550 m or 600 m, etc.

[0170] Therefore, the inventor conducted a series of tests. For the energy storage device 10 with an energy density in the range of 750 Wh / L < D ≤ 900 Wh / L, only V and L1 of the energy storage device 10 in different embodiments and comparative examples were changed, and the temperature of the emissions discharged was obtained in the case of thermal runaway of the energy storage device 10. The results are shown in Table 5.

[0171] Table 5 Influence of V and L1 of the energy storage device 10 on the emissions in the case of thermal runaway

[0172]

[0173] As can be seen from Table 5 above, for the battery cell 30 with an energy density D in the range of 550 Wh / L < D ≤ 750 Wh / L, in the comparative example where V is less than 500 L and L1 is less than 5 m, the temperature of the emissions discharged during the thermal runaway of the energy storage device 10 is relatively high, which is not conducive to the condensation of the emissions in the collection chamber 111a and the exhaust passage 11b. In the comparative example where V is greater than 10,000 L and L1 is greater than 600 m, the sealing interface of the cabinet 11 fails. It can be seen that the residence time of the emissions in the collection chamber 111a and the exhaust passage 11b is too long and cannot be discharged in time.

[0174] After systematic analysis and long-term practice, the inventors found that for the battery cell 30 with an energy density D in the range of 750 Wh / L < D ≤ 900 Wh / L, the chemical reaction during its thermal runaway is more intense. By setting 800 L ≤ V ≤ 10,000 L and 8 m ≤ L1 ≤ 600 m, it is beneficial to improve the condensation efficiency of the emissions in the collection chamber 111a and the exhaust passage 11b, so as to increase the content of pollutants in the emissions discharged into the environment. At the same time, it is also beneficial to reduce the volume occupied by the collection chamber 111a and the exhaust passage 11b, which is conducive to improving the energy density of the energy storage device 10 and facilitating the timely discharge of the emissions, reducing the risk of sealing failure of the cabinet 11.

[0175] In some embodiments, 800 L ≤ V ≤ 1500 L and 8 m ≤ L1 ≤ 20 m.

[0176] Optionally, V can be 800 L, 850 L, 900 L, 950 L or 1000 L, etc., and L1 can be 8 m, 9 m, 10 m, 11 m, 12 m, 13 m, 14 m, 15 m, 16 m, 17 m, 18 m, 19 m or 20 m, etc.

[0177] After further systematic analysis and practice, the inventors found that by setting 800 L ≤ V ≤ 1500 L and 8 m ≤ L1 ≤ 20 m, when the energy storage device 10 undergoes thermal runaway, on the premise of meeting the cooling and condensation requirements of the emissions, it is beneficial to further reduce the volume of the collection chamber 111a and the exhaust passage 11b, so as to further improve the energy density of the energy storage device 10, and further facilitate the timely discharge of the emissions, reducing the risk of sealing failure of the cabinet 11.

[0178] In some embodiments, the exhaust passage 11b has an inlet near one end of the accommodation chamber 11a, and the length of the shortest path from the first pressure relief mechanism 22 to the inlet is L2, where 0.1 m ≤ L2 ≤ 4 m.

[0179] Optionally, L2 can be 0.1 m, 0.5 m, 1 m, 1.5 m, 2 m, 2.5 m, 3 m, 3.5 m or 4 m, etc.

[0180] The shortest path L2 from the first pressure relief mechanism 22 to the inlet can be the shortest path for the emissions discharged by the first pressure relief mechanism 22 from the collection chamber 111a to the inlet of the exhaust passage 11b. Since the emissions will be preliminarily cooled during the process from the first pressure relief mechanism 22 to the exhaust passage 11b, the larger L2 is, the more conducive it is to increasing the time for the emissions to flow through the collection chamber 111a, and thus the more conducive it is to improving the efficiency of cooling and condensing the emissions in the collection chamber 111a. On the contrary, the smaller L2 is, the more conducive it is to increasing the rate of discharging the emissions outside the cabinet 11, so as to reduce the rate of pressure rise in the collection chamber 111a and reduce the risk of the cabinet 11 being sealed due to excessive pressure in the accommodation chamber 11a.

[0181] Therefore, the inventor conducted a series of tests. For different energy storage devices 10, only the value of L2 was changed while other parameters remained unchanged, and the test results are shown in Table 6.

[0182] Table 6 Influence of L2 of the energy storage device 10 on the temperature of the emissions and the sealing performance of the cabinet 11

[0183]

[0184] As shown in Table 6, in the comparative example where L2 is less than 0.1 m, the temperature of the discharged emissions is relatively high, indicating that the emissions are not sufficiently cooled and condensed in the collection chamber 111a. In the comparative example where L2 is greater than 4 m, the sealing of the cabinet 11 fails, indicating that the pressure inside the cabinet 11 is too high and the emissions cannot be discharged in time.

[0185] Therefore, through systematic analysis and long-term practice, the inventor found that by setting 0.1 m ≤ L2 ≤ 4 m, in the case of thermal runaway of the energy storage device 10, it is conducive to increasing the retention time of the emissions in the accommodation chamber 11a, improving the efficiency of cooling and condensing the emissions, and thus reducing the content of pollutants in the emissions discharged outside the cabinet 11. At the same time, it can also reduce the risk of the cabinet 11 being sealed due to excessive pressure in the accommodation chamber 11a.

[0186] In some embodiments, such as Figure 6As shown, the first pressure relief mechanism 22 includes a first valve body 221 and a first valve core 222. The first valve body 221 is connected to the box body 21 and has a first pressure relief channel 22a. The first valve core 222 is configured to be able to move relative to the first valve body 221 along the first axial direction X of the first pressure relief mechanism 22 to block or open the first pressure relief channel 22a. Under the pressure of 2 Kpa - 20 Kpa, along the first axial direction X, the maximum stroke of the first valve core 222 relative to the first valve body 221 is H1, and the perimeter of the outlet of the first pressure relief channel 22a at the end facing the first valve core 222 is a1. The exhaust channel 11b has an air inlet at the end facing the accommodation cavity 11a, and the sum of the cross-sectional areas of the air inlets is S, and 0.1 ≤ a1·H1 / S ≤ 10.

[0187] The first valve body 221 is connected to the box body 21, then the first valve body 221 can be sealingly connected to the box body 21, and the first valve core 222 can be connected to the first valve body 221 through an elastic member. Without external force, the first valve core 222 blocks the outlet of the first pressure relief channel 22a.

[0188] In the case of thermal runaway of the battery cell 30, the battery cell 30 discharges emissions into the box body 21. As the pressure in the box body 21 continues to rise, the first pressure relief mechanism 22 is actuated. Under the action of the internal pressure of the box body 21, the first valve core 222 moves relative to the first valve body 221 along the first axial direction X, the first pressure relief channel 22a is opened, and the emissions flow through the first pressure relief channel 22a to the gap between the first valve body 221 and the first valve core 222, and then are discharged into the accommodation cavity 11a.

[0189] Under the pressure of 2 Kpa - 20 Kpa, the stroke of the first valve core 222 relative to the first valve body 221 along the first axial direction X is H1, and the perimeter of the outlet of the first pressure relief channel 22a at the end facing the first valve core 222 is a1, then a1·H1 is the maximum flow area for the emissions to discharge between the first valve body 221 and the first valve core 222.

[0190] The cabinet 11 can have one or more exhaust channels 11b. Therefore, the cabinet 11 can have one or more air inlets, and S can be the sum of the areas of all the air inlets.

[0191] Optionally, a1·H1 / S can be 0.1, 0.5, 0.8, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10, etc.

[0192] It can be understood that, to a certain extent, the larger the value of a1·H1 / S is, the more conducive it is to quickly discharging the emissions discharged into the accommodation cavity 11a through the first pressure relief mechanism 22 to the outside of the accommodation cavity 11a, so as to reduce the rate of pressure increase in the accommodation cavity 11a, and further reduce the risk of seal failure of the cabinet body 11. And to a certain extent, the smaller the value of a1·H1 / S is, the more conducive it is to increasing the retention time of the emissions discharged through the first pressure relief mechanism 22 in the accommodation cavity 11a, so as to facilitate more sufficient cooling and condensation of the emissions and reduce the content of pollutants in the emissions discharged to the outside of the cabinet body 11.

[0193] Therefore, after systematic analysis and long-term practice, the inventor found that by setting 0.1 ≤ a1·H1 / S ≤ 10, it is beneficial to increase the retention time of the emissions in the accommodation cavity 11a, so as to facilitate more sufficient cooling and condensation of the emissions, and at the same time, it is also beneficial to reduce the rate of pressure increase in the accommodation cavity 11a, and further reduce the risk of seal failure of the cabinet body 11.

[0194] In some embodiments, 0.5 ≤ a1·H1 / S ≤ 5.

[0195] Optionally, a1·H1 / S can be 0.5, 0.8, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, etc.

[0196] After further systematic analysis and long-term practice, the inventor found that by setting 0.5 ≤ a1·H1 / S ≤ 5, it is beneficial to further increase the retention time of the emissions in the accommodation cavity 11a, so as to facilitate more sufficient cooling and condensation of the emissions, and at the same time, it is also further beneficial to reduce the rate of pressure increase in the accommodation cavity 11a, and further reduce the risk of seal failure of the cabinet body 11.

[0197] In some embodiments, as Figure 7 shown, the second pressure relief mechanism 40 includes a second valve body 41 and a second valve core 42. The second valve body 41 is connected to the cabinet body 11 and has a second pressure relief channel 40a. The second valve core 42 is configured to be able to move relative to the second valve body 41 along the second axial direction Y of the second pressure relief channel 40a to block or open the second pressure relief channel 40a. Under the pressure of 2Kpa - 20Kpa, the maximum stroke H2 of the second valve core 42 relative to the second valve body 41 along the second axial direction Y satisfies: 0.1mm ≤ H2 ≤ 1mm.

[0198] The second valve body 41 is connected to the cabinet body 11. The second valve body 41 can be hermetically connected to the cabinet body 11, and the second valve core 42 can be connected to the second valve body 41 through an elastic member. When the energy storage device 10 is operating normally, the second valve core 42 blocks the second pressure relief channel 40a. In the case of thermal runaway of the energy storage device 10, as the air pressure in the accommodation cavity 11a increases, the second valve core 42 moves relative to the second valve body 41 in the second direction under the action of the air pressure in the accommodation cavity 11a to open the second channel. The emissions in the accommodation cavity 11a flow through the exhaust channel 11b to the second pressure relief channel 40a, and then are discharged to the outside of the cabinet body 11 through the gap between the second valve body 41 and the second valve core 42.

[0199] It can be understood that under the pressure of 2Kpa - 20Kpa, the larger the maximum stroke H2 of the second valve core 42 along the second axial direction Y relative to the second valve body 41, the more convenient it is to form a larger gap between the second valve core 42 and the second valve body 41, enabling the emissions to be quickly discharged to the outside of the cabinet body 11 and reducing the risk of the cabinet body 11's seal failure due to excessive internal pressure of the energy storage device 10. And the smaller H2 is, the more beneficial it is to increase the retention time of the emissions in the accommodation cavity 11a, thereby improving the cooling and condensation effect of the emissions in the accommodation cavity 11a and reducing the content of pollutants in the emissions discharged to the outside of the cabinet body 11.

[0200] Optionally, H2 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm, etc.

[0201] Therefore, the inventor conducted a series of experiments. In the experiments, only the maximum stroke H2 of the second valve core 42 along the second axial direction Y relative to the second valve body 41 under the pressure of 2Kpa - 20Kpa in different energy storage devices 10 was changed, and the experimental results are shown in Table 7.

[0202] Table 7 Influence of H2 of the second pressure relief mechanism 40 on the temperature of emissions and the sealing performance of the cabinet body 11

[0203]

[0204] As can be seen from Table 7 above, in the comparative example where H2 is less than 0.08mm, the seal of the cabinet body 11 fails, indicating that the emissions cannot be discharged in time, easily causing the risk of excessive pressure in the accommodation cavity 11a. And in the comparative example where H2 is greater than 1mm, the temperature of the emissions discharged to the outside of the cabinet body 11 is relatively high, indicating that insufficient condensation and cooling occur in the accommodation cavity 11a.

[0205] Therefore, after systematic analysis and long-term practice, the inventor found that by setting 0.1 mm ≤ H2 ≤ 1 mm, it is beneficial to reduce the risk of seal failure of the cabinet 11 caused by excessive air pressure in the accommodation cavity 11a, and at the same time, it is convenient for the emissions to be sufficiently cooled and condensed in the accommodation cavity 11a and the exhaust passage 11b, further reducing the content of pollutants in the emissions discharged outside the cabinet 11.

[0206] In some embodiments, the perimeter of the second pressure relief passage 40a at the outlet of one end facing the second valve element 42 is a2, satisfying: 10 mm 2 ≤ a2·H2 ≤ 150 mm 2 .

[0207] In the case of thermal runaway of the energy storage device 10, the battery pack 20 discharges emissions into the accommodation cavity 11a via the first pressure relief mechanism 22. As the pressure in the accommodation cavity 11a continues to rise, the second pressure relief mechanism 40 is actuated. Under the action of the internal pressure of the accommodation cavity 11a, the second valve element 42 moves along the second axial direction Y relative to the second valve body 41, and the second pressure relief passage 40a is opened. The emissions flow through the second pressure relief passage 40a to the gap between the second valve body 41 and the second valve element 42, and then are discharged to the outside of the cabinet 11.

[0208] Under the pressure of 2 Kpa - 20 Kpa, the stroke of the second valve element 42 relative to the second valve body 41 along the first axial direction X is H2, and the perimeter of the outlet of one end of the second pressure relief passage 40a facing the second valve element 42 is a2, then a2·H2 is the maximum flow area for the emissions to be discharged between the second valve body 41 and the second valve element 42.

[0209] Optionally, a2·H2 can be 10 mm 2 , 20 mm 2 , 30 mm 2 , 40 mm 2 , 50 mm 2 , 60 mm 2 , 70 mm 2 , 80 mm 2 , 90 mm 2 , 100 mm 2 , 110 mm 2 , 120 mm 2 , 130 mm 2 , 140 mm 2 or 150 mm 2 etc.

[0210] It can be understood that, to a certain extent, the larger the value of a2·H2, the more conducive it is for the emissions in the accommodation cavity 11a to be quickly discharged to the outside of the cabinet body 11 through the second pressure relief mechanism 40, so as to reduce the rate of pressure increase in the accommodation cavity 11a, and further reduce the risk of seal failure of the cabinet body 11. And to a certain extent, the smaller the value of a2·H2, the more conducive it is to increase the retention time of the emissions in the accommodation cavity 11a, so as to facilitate more sufficient cooling and condensation of the emissions and reduce the content of pollutants in the emissions discharged to the outside of the cabinet body 11.

[0211] Therefore, after systematic analysis and long-term practice, the inventor found that by setting 10mm 2 ≤a2·H2≤150mm 2 , it is conducive to increasing the retention time of the emissions in the accommodation cavity 11a, so as to facilitate more sufficient cooling and condensation of the emissions, and at the same time, it is conducive to reducing the rate of pressure increase in the accommodation cavity 11a, and further reducing the risk of seal failure of the cabinet body 11.

[0212] In some embodiments, the melting point T of the wall of the exhaust passage 11b satisfies: T≥80°C.

[0213] The exhaust passage 11b may include multiple segments, and the materials of different segments may be the same or different.

[0214] In the case of thermal runaway of the energy storage device 10, the temperature of the emissions released by the battery cell 30 is relatively high. During the process of the emissions flowing through the exhaust passage 11b, they will impact the wall of the exhaust passage 11b and transfer heat to the wall of the exhaust passage 11b, and the temperature of the emissions is usually less than 80°C.

[0215] By setting the melting point T of the wall of the exhaust passage 11b to satisfy: T≥80°C, it is conducive to reducing the risk of melting of the wall of the exhaust passage 11b in the case of thermal runaway of the energy storage device 10, and further reducing the risk of seal failure of the exhaust passage 11b, so as to reduce the risk of emissions directly being discharged to the outside of the cabinet body 11 through the discharge passage.

[0216] In some embodiments, the energy storage device 10 includes a plurality of second pressure relief mechanisms 40 and a plurality of exhaust passages 11b, and at least one exhaust passage 11b is configured to be able to guide the emissions to any one of the second pressure relief mechanisms 40.

[0217] Optionally, different second pressure relief mechanisms 40 may have the same or different actuation thresholds. The second pressure relief mechanisms 40 with the same actuation threshold may be actuated simultaneously, while the second pressure relief mechanisms 40 with different actuation thresholds are actuated at different times.

[0218] At least one exhaust passage 11b is configured to be able to guide emissions to any one of the second pressure relief mechanisms 40. Any one of the second pressure relief mechanisms 40 corresponds to at least one exhaust passage 11b, so that the emissions in the accommodation cavity 11a can act on the corresponding second pressure relief mechanism 40 through at least one exhaust passage 11b.

[0219] By providing that the energy storage device 10 includes a plurality of second pressure relief structures and exhaust passages 11b, in the case of thermal runaway of the energy storage device 10, emissions can be discharged through the plurality of exhaust passages 11b and the plurality of second pressure relief mechanisms 40, which is beneficial to improving the timeliness of emission discharge and reducing the risk of explosion of the energy storage device 10 due to thermal runaway.

[0220] In some embodiments, at least one bend is provided in the exhaust passage 11b.

[0221] Optionally, the exhaust passage 11b can be bent at one or more places.

[0222] It can be understood that during the process of the emissions flowing through the bend of the exhaust passage 11b, the emissions will impact the inner wall of the exhaust passage 11b, and particles or droplets therein will be blocked by the exhaust passage 11b and condense and settle, and finally remain in the exhaust passage 11b. In this way, it is beneficial to further reduce the content of pollutants in the emissions discharged into the environment.

[0223] In some embodiments, as Figure 5 shown, the exhaust passage 11b includes a pipe 111b, and the pipe 111b is connected to the cabinet 11.

[0224] Optionally, the pipe 111b of the exhaust passage 11b can be installed on the cabinet 11 by means of sliding, hinging, threaded connection, welding, or riveting, etc.

[0225] By connecting the pipe 111b to the cabinet 11, it is beneficial to improve the cooperation strength between the pipe 111b and the cabinet 11, make the structure of the exhaust passage 11b more stable and reliable, and facilitate the exhaust passage 11b to cope with more complex working conditions of the energy storage device 10.

[0226] Second, as Figure 1 shown, the energy storage system 1 provided by the embodiments of the present application includes the energy storage device 10 provided by any one of the above embodiments.

[0227] The energy storage device 10 provided by the embodiments of the present application has the same technical effects as those of the energy storage device 10 provided by any one of the above embodiments, and will not be elaborated here.

[0228] In some embodiments, as Figures 2 to 7As shown, the energy storage device 10 includes a battery pack 20, a cabinet 11, and a second pressure relief mechanism 40. The battery pack 20 includes a box body 21, battery cells 30, and a first pressure relief mechanism 22. The battery cells 30 are accommodated in the box body 21, and the first pressure relief mechanism 22 is provided on the box body 21. The cabinet 11 has a receiving cavity 11a, the battery pack 20 is accommodated in the receiving cavity 11a, the cabinet 11 has an exhaust passage 11b, and the exhaust passage 11b communicates with the receiving cavity 11a. The second pressure relief mechanism 40 is provided on the cabinet 11, and the exhaust passage 11b is configured to be able to guide the emissions discharged by the first pressure relief mechanism 22 to the second pressure relief mechanism 40 to discharge the cabinet 11. The receiving cavity 11a has a collection cavity 111a, the collection cavity 111a is a cavity body in the receiving cavity 11a, the exhaust passage 11b communicates with the collection cavity 111a, and the volume V of the collection cavity 111a satisfies: 300L ≤ V ≤ 10000L. Along the extending direction of the exhaust passage 11b, the length of the shortest path of the exhaust passage 11b is L1, and 2m ≤ L1 ≤ 600m. The first pressure relief mechanism 22 includes a first valve body 221 and a first valve core 222. The first valve body 221 is connected to the box body 21 and has a first pressure relief passage 22a. The first valve core 222 is configured to be able to move relative to the first valve body 221 along the first axial direction X of the first pressure relief mechanism 22 to block or open the first pressure relief passage 22a. Under the pressure of 2Kpa - 20Kpa, along the first axial direction X, the maximum stroke of the first valve core 222 relative to the first valve body 221 is H1, and the perimeter of the outlet of the first pressure relief passage 22a at the end facing the first valve core 222 is a1. The exhaust passage 11b has an air inlet at the end facing the receiving cavity 11a, and the sum of the cross-sectional areas of the air inlets is S, and 0.1 ≤ a1·H1 / S ≤ 10. The second pressure relief mechanism 40 includes a second valve body 41 and a second valve core 42. The second valve body 41 is connected to the cabinet 11 and has a second pressure relief passage 40a. The second valve core 42 is configured to be able to move relative to the second valve body 41 along the second axial direction Y of the second pressure relief passage 40a to block or open the second pressure relief passage 40a. Under the pressure of 2Kpa - 20Kpa, the maximum stroke H2 of the second valve core 42 relative to the second valve body 41 along the second axial direction Y satisfies: 0.1mm ≤ H2 ≤ 1mm. The perimeter of the outlet of the second pressure relief passage 40a at the end facing the second valve core 42 is a2, and it satisfies: 10mm 2 ≤ a2·H2 ≤ 150mm 2 . The melting point T of the wall of the exhaust passage 11b satisfies: T ≥ 80°C. The energy storage device includes a plurality of second pressure relief mechanisms 40 and a plurality of exhaust passages 11b. At least one exhaust passage 11b is configured to be able to guide the emissions to any one of the second pressure relief mechanisms 40. At least one bend is provided in the exhaust passage 11b. The exhaust passage 11b includes a pipe 111b, and the pipe 111b is connected to the cabinet 11.

[0229] The energy storage device 10 provided by the embodiment of the present application is configured such that the cabinet 11 has an exhaust passage 11b, and the exhaust passage 11b is communicated with the accommodation cavity 11a. In the case of thermal runaway of the energy storage device 10, the exhaust passage 11b can guide the emissions discharged by the first pressure relief mechanism 22 to the second pressure relief mechanism 40 and discharge them to the outside of the cabinet 11 through the second pressure relief mechanism 40. In this way, during the process of the emissions flowing through the exhaust passage 11b, condensation, adsorption and other effects will occur in the exhaust passage 11b, and at least part of the pollutants in the emissions will be deposited and retained in the exhaust passage 11b. Therefore, it is beneficial to reduce the pollutant content in the emissions discharged into the environment, and further beneficial to reduce the pollution to the environment in the case of thermal runaway of the energy storage device 10.

[0230] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the technical features 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: A battery pack comprises a box, a battery cell and a first pressure relief mechanism, wherein the battery cell is accommodated in the box, and the first pressure relief mechanism is arranged in the box; A cabinet having a housing cavity, wherein the battery pack is accommodated in the housing cavity, and wherein the cabinet has an exhaust passage, wherein the exhaust passage is communicated with the housing cavity; The second pressure relief mechanism is provided in the cabinet, and the exhaust passage is configured to guide the exhaust discharged by the first pressure relief mechanism to the second pressure relief mechanism to be discharged from the cabinet.

2. The energy storage device according to claim 1, characterized in that: The accommodating chamber has a collecting chamber, which is a hollow cavity in the accommodating chamber. The exhaust channel is connected to the collecting chamber, and the volume V of the collecting chamber satisfies: 300L≤V≤10000L.

3. The energy storage device according to claim 2, characterized in that: Along the extension direction of the exhaust channel, the length of the shortest path of the exhaust channel is L1, 2m≤L1≤600m.

4. The energy storage device according to claim 3, characterized in that: The energy density D of the battery cell satisfies: 300Wh / L≤D≤550Wh / L, 300L≤V≤4000L, 2m≤L1≤150m.

5. The energy storage device according to claim 4, characterized in that: 300L≤V≤1000L, 5m≤L1≤15m.

6. The energy storage device according to claim 3, characterized in that: The energy density D of the battery cell satisfies: 550Wh / L<D≤750Wh / L, and 500L≤V≤8000L, 5m≤L1≤300m.

7. The energy storage device according to claim 6, characterized in that: 500L≤V≤1200L, 5m≤L1≤15m.

8. The energy storage device according to claim 3, characterized in that: The energy density D of the battery cell satisfies: 750Wh / L<D≤900Wh / L, and 800L≤V≤10000L, 8m≤L1≤600m.

9. The energy storage device according to claim 8, characterized in that: 800L≤V≤1500L, 8m≤L1≤20m.

10. The energy storage device according to claim 1, characterized in that: The exhaust passage has an inlet close to one end of the accommodating chamber, and the length of the shortest path from the first pressure relief mechanism to the inlet is L2, 0.1m≤L2≤4m.

11. The energy storage device according to claim 1, characterized in that: The first pressure relief mechanism comprises a first valve body and a first valve core, the first valve body is connected to the box body and has a first pressure relief passage, the first valve core is configured to be able to move relative to the first valve body along a first axial direction of the first pressure relief mechanism to block or open the first pressure relief passage; Under the pressure of 2Kpa-20Kpa, along the first axial direction, the maximum stroke of the first valve core relative to the first valve body along the first axial direction is H1, and the circumference of the outlet of the first pressure relief channel toward one end of the first valve core is a1; The exhaust passage has an air inlet facing one end of the accommodating cavity, and the sum of the cross-sectional areas of the air inlet is S, 0.1≤a1·H1 / S≤10.

12. The energy storage device according to claim 11, characterized in that: 0.5≤a1·H1 / S≤5.

13. The energy storage device according to any one of claims 1 to 12, characterized in that: The second pressure relief mechanism comprises a second valve body and a second valve core, the second valve body is connected to the cabinet and has a second pressure relief passage, the second valve core is configured to be able to move relative to the second valve body along a second axial direction of the second pressure relief passage to block or open the second pressure relief passage; Under the pressure of 2Kpa-20Kpa, the maximum stroke H2 of the second valve core relative to the second valve body along the second axial direction satisfies: 0.1mm≤H2≤1mm.

14. The energy storage device according to claim 13, characterized in that: The circumference of the second pressure relief channel toward the outlet of one end of the second valve core is a2, which satisfies: 10 mm 2 ≤a2·H2≤150mm 2 .

15. The energy storage device according to any one of claims 1 to 12, characterized in that: The melting point T of the wall of the exhaust passage satisfies: T≥80°C.

16. The energy storage device according to any one of claims 1 to 12, characterized in that: The energy storage device includes a plurality of the second pressure relief mechanisms and a plurality of the exhaust passages, and at least one of the exhaust passages is configured to guide the exhaust to any one of the second pressure relief mechanisms.

17. The energy storage device according to any one of claims 1 to 12, characterized in that: The exhaust passage is provided with at least one bend.

18. The energy storage device according to any one of claims 1 to 12, characterized in that: The exhaust passage includes a pipeline connected to the cabinet.

19. An energy storage system, characterized in that: Comprising the energy storage device according to any one of claims 1 to 18.

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