Energy storage device and energy storage system

Abstract

The utility model discloses an energy storage device and an energy storage system, the energy storage device comprises an outer box body, a heat insulation layer and a flame retardant structure, and an accommodating space for accommodating a battery device is arranged in the outer box body; the heat insulation layer is made of heat insulation materials; the heat insulation layer is arranged on the wall of the outer box body and located on the side, facing the containing space, of the wall and / or arranged between at least two walls of the outer box body, and the wall supports the heat insulation layer; the flame-retardant structure is located in the heat insulation layer and / or located on the side, facing the containing space, of the heat insulation layer. According to the energy storage device provided by the embodiment of the utility model, the thermal insulation layer and the flame-retardant structure are arranged to slow down the heat transfer speed, and when the thermal runaway of the energy storage device occurs, the time for transferring the temperature to the adjacent energy storage device is prolonged; the heat insulation layer is supported by the wall, a supporting structure of the heat insulation layer does not need to be arranged, the internal space of the energy storage device is saved, and the cost of the supporting structure is reduced.

Description

Energy storage devices and energy storage systems Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an energy storage device and an energy storage system. Background Technology

[0002] During the operation of an energy storage device, when a battery pack experiences thermal runaway and triggers a fire, the large amount of heat released will be transferred from the thermally runaway device to adjacent devices. This heat, through the heat conduction of the adjacent devices' outer casings, will affect the battery packs within those adjacent devices, potentially causing thermal runaway in those same battery packs and further spreading the fire. Therefore, improvements are needed. Summary of the Invention

[0003] In view of the above problems, this utility model provides an energy storage device and an energy storage system, which, through the wall-supported heat insulation layer, slows down heat transfer while saving internal space of the energy storage device and reducing costs.

[0004] In a first aspect, the present invention provides an energy storage device, comprising an outer casing, a heat insulation layer, and a flame-retardant structure. The outer casing has an internal space for housing a battery device. The heat insulation layer is made of heat-insulating material. The heat insulation layer is disposed on the wall of the outer casing and located on the side of the wall facing the housing space, and / or the heat insulation layer is disposed between at least two walls of the outer casing, the walls supporting the heat insulation layer. The flame-retardant structure is located inside the heat insulation layer and / or the flame-retardant structure is located on the side of the heat insulation layer facing the housing space.

[0005] In the above technical solution, by setting up a heat insulation layer and a flame-retardant structure, the heat transfer rate is slowed down, and when thermal runaway of the energy storage device occurs, the time for temperature to be transferred to adjacent energy storage devices is extended. When the outer casing wall is a single-layer structure, the heat insulation layer is set on the outer casing wall and located on the side of the wall facing the containment space. When the outer casing wall is a multi-layer structure, a hollow structure is formed between the multi-layer structures, and the heat insulation layer is set in the hollow structure between at least two layers of walls. The heat insulation layer is supported by the wall, eliminating the need for a support structure for the heat insulation layer, saving internal space of the energy storage device, and reducing the cost of the support structure.

[0006] In some embodiments, the insulation layer is a multi-layer composite structure, and the insulation layer comprises materials with at least two fire resistance ratings.

[0007] In the above technical solution, the insulation layer includes materials of at least two fire resistance grades, which can reduce the thickness of the insulation layer, reduce the cost of the insulation layer, and save internal space of the energy storage device while achieving the same insulation performance.

[0008] In some embodiments, at least two fire-resistant materials are arranged along the thickness direction of the wall, and the fire resistance of the fire-resistant materials decreases from the outside of the outer casing to the receiving space or decreases from both sides to the center.

[0009] In the above technical solution, by placing high-fire-resistant materials on the outside of the wall, when thermal runaway occurs, heat enters the energy storage device from the outside, and the high-fire-resistant materials can effectively control and reduce the heat transfer rate.

[0010] In some embodiments, the heat insulation material of the heat insulation layer is at least one of ceramic fiber mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam.

[0011] In the above technical solutions, materials such as ceramic fiber, mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam all have porous structures, which can significantly block heat transfer and convective heat transfer, and have low thermal conductivity; they have strong heat insulation effect at the same thickness, and can also reduce the thickness of the heat insulation layer; the above materials have stable chemical properties, are moisture-resistant, and are not easy to age; they have low density and are convenient to construct and use.

[0012] In some embodiments, the insulation layer is fixed to the wall.

[0013] In the above technical solution, the insulation layer is fixed to the wall. The installation of the insulation layer by fixing makes the installation of the insulation layer and the wall more stable and the insulation layer is not easy to detach from the wall.

[0014] In some embodiments, an adhesive layer formed of glue is provided between the heat insulation layer and the wall.

[0015] In the above technical solution, an adhesive layer formed by glue is provided between the insulation layer and the wall. The insulation layer is fixed to the wall by glue bonding, which is convenient to operate. The wall can support the insulation layer, eliminating the need for other fixing structures, reducing the thickness between the insulation layer and the wall, and saving internal space of the energy storage device.

[0016] In some embodiments, the insulation layer is fixed to the wall by fasteners.

[0017] In the above technical solution, the insulation layer is fixed to the wall by fasteners, which facilitates the installation and removal of the insulation layer. When the outer casing is damaged, the insulation layer can be removed from the outer casing by removing the fasteners, and the insulation layer can be reused.

[0018] In some embodiments, the insulation layer is located between at least two of the walls, and the insulation layer rests against or is sandwiched between the two walls.

[0019] In the above technical solution, the insulation layer rests against or is sandwiched between two walls. The installation of the insulation layer is simple, requiring no other fixing structures, reducing the thickness between the insulation layer and the walls, and saving internal space in the energy storage device. In some embodiments, the energy storage device further includes a flame-retardant structure, which is located inside the insulation layer and / or on the side of the insulation layer facing the receiving space.

[0020] In some embodiments, the flame-retardant structure is a cooling pipe capable of storing or circulating coolant.

[0021] In the above technical solution, by setting the flame-retardant structure as a cooling pipe, when the temperature of the wall of the energy storage device rises, the coolant in the cooling pipe can absorb heat, reduce the temperature of the wall, and delay the spread of heat to the containment space; when the energy storage device is running in extremely cold regions or deserts, the coolant inside the cooling pipe can also play a role in regulating the internal temperature of the energy storage device.

[0022] In some embodiments, the wall is provided with a spray hole, and the cooling pipe generates a liquid outlet hole or opens a liquid outlet hole when heated, and the liquid outlet hole is in communication with the spray hole.

[0023] In the above technical solution, by setting out liquid outlet holes that can be generated by ablation or by setting out liquid outlet holes with valves on the structure of the cooling pipe, when the temperature of the wall rises to the preset temperature, the coolant in the cooling pipe is sprayed out through the liquid outlet holes and sprayed onto the inside and outside of the energy storage device through the spray holes on the wall, so as to reduce the temperature or extinguish the fire.

[0024] In some embodiments, the flame-retardant structure is a porous partition, and the porous partition stores a heat-decomposing flame retardant.

[0025] In the above technical solution, by storing a thermally decomposable flame retardant in a porous partition, when the temperature generated by the thermal runaway of an adjacent energy storage device spreads to the energy storage device, the thermally decomposable flame retardant will decompose to generate non-flammable gas and fill the space between at least two layers of walls of the containment space or the outer casing, preventing the flame from spreading to the containment space.

[0026] In some embodiments, the thermally decomposable flame retardant is at least one of aluminum hydroxide and sodium bicarbonate.

[0027] In the above technical solution, aluminum hydroxide and sodium bicarbonate are used as decomposition-type flame retardants, which are environmentally friendly, have complementary flame retardant mechanisms, are widely applicable, and are low in cost. Both aluminum hydroxide and sodium bicarbonate are halogen-free flame retardants, and do not produce toxic or corrosive gases such as hydrogen halides during decomposition, nor do they generate strong carcinogens such as dioxins. The decomposition temperature of aluminum hydroxide is approximately 200~320℃, and that of sodium bicarbonate is approximately 150~270℃. Both decomposition temperatures exceed ambient temperature, preventing premature decomposition and failure before reaching the preset temperature. The flame retardant mechanism of aluminum hydroxide involves absorbing a large amount of heat during decomposition, lowering the wall temperature, and the generated Al2O3 forms a dense heat-insulating layer on the wall surface, isolating oxygen and heat. Sodium bicarbonate releases a large amount of CO2 gas instantaneously during decomposition, forming a "gas barrier" that rapidly inhibits flame spread. The combination of aluminum hydroxide and sodium bicarbonate solves the problem of high dosage when aluminum hydroxide is used alone and compensates for the slightly weaker thermal stability of sodium bicarbonate, significantly improving flame retardant efficiency.

[0028] In some embodiments, the flame-retardant structure is a phase change layer, which is used to absorb heat.

[0029] In the above technical solution, when the flame-retardant structure is a phase change layer, when the temperature generated by the thermal runaway of the adjacent energy storage device spreads to the energy storage device, the phase change material reduces the heat entering the containment space through phase change heat absorption, thereby reducing the heat transfer rate.

[0030] In some embodiments, the phase change layer is paraffin, polyethylene glycol, or a ceramic-paraffin composite material.

[0031] In the above technical solutions, the latent heat of phase change of paraffin can reach 180~250kJ / kg, which is much higher than that of ordinary inorganic salt PCM. It has a large energy storage density and high heat absorption / release efficiency. Polyethylene glycol is a food-grade material that is non-volatile and odorless, and will not pollute the environment even if it leaks. The ceramic-paraffin composite material is a composite phase change material that combines ceramic fillers with paraffin through physical compounding or chemical modification. It retains the high latent heat of paraffin and solves the problems of poor thermal conductivity and easy leakage.

[0032] In some embodiments, the exterior of the wall is provided with a reflective coating or a mirror layer.

[0033] In the above technical solution, by setting a reflective coating or mirror layer on the outside of the wall, the reflective coating or mirror layer reflects heat, reducing the heat transferred to the inside of the energy storage device and slowing down the heat transfer rate.

[0034] In a second aspect, the present invention provides an energy storage system, comprising: an energy storage device according to an embodiment of the first aspect of the present invention.

[0035] In the above technical solution, the energy storage system includes an energy storage device according to the first aspect of the present invention. By setting a heat insulation layer and a flame-retardant structure, the heat transfer rate is slowed down. When thermal runaway of the energy storage device occurs, the time for temperature to be transferred to adjacent energy storage devices is extended. When the outer casing wall is a single-layer structure, the heat insulation layer is set on the outer casing wall and located on the side of the wall facing the receiving space. When the outer casing wall is a multi-layer structure, a hollow structure is formed between the multi-layer structures. The heat insulation layer is set in the hollow structure between at least two layers of walls. The heat insulation layer is supported by the wall, eliminating the need for a support structure for the heat insulation layer, saving internal space of the energy storage device, and reducing the cost of the support structure.

[0036] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0037] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0038] Figure 1 is a front view of an energy storage device according to some embodiments of the present invention;

[0039] Figure 2 is a partial structural cross-sectional view of the outer casing according to the first embodiment of the present invention;

[0040] Figure 3 is a partial structural cross-sectional view of the outer casing according to the second embodiment of the present utility model;

[0041] Figure 4 is a partial structural cross-sectional view of the outer casing according to the third embodiment of the present utility model;

[0042] Figure 5 is a partial structural cross-sectional view of the outer casing according to the fourth embodiment of the present invention.

[0043] Figure label:

[0044] 100. Energy storage device; 10. Outer casing; 11. Support frame; 12. Plate; 13. Wall; 130. Outer wall; 131. Inner wall; 20. Insulation layer; 21. First insulation layer; 22. Second insulation layer; 23. Third insulation layer; 30. Flame-retardant structure. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0046] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order or hierarchy.

[0047] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments.

[0048] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "attachment," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0049] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0050] In the embodiments of this utility model, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this utility model shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this utility model.

[0051] In this utility model, "multiple" refers to two or more.

[0052] In the embodiments of this utility model, unless otherwise specified, all embodiments and optional embodiments of this utility model can be combined with each other to form new technical solutions.

[0053] In the embodiments of this utility model, unless otherwise specified, all technical features and optional technical features of this utility model can be combined with each other to form new technical solutions.

[0054] In embodiments of this invention, the battery device may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar. For example, a battery cell assembly is typically formed by arranging multiple battery cells; a battery cell assembly may also be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module may be formed by bundling multiple battery cells together with cable ties.

[0055] The battery device can be a battery pack, which includes a housing and one or more individual battery cells housed within the housing. The individual battery cells can be battery modules, which can be housed within the housing by fixing the battery modules to the housing; alternatively, multiple individual battery cells can be housed within the housing by directly fixing them to the housing.

[0056] In embodiments of this invention, the energy storage device includes one or more battery clusters to increase the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0057] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices.

[0058] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0059] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet.

[0060] In some embodiments, the energy storage device may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0061] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device via piping to regulate the temperature of the individual battery cells.

[0062] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0063] As an example, the central control module can serve as the battery management unit for an energy storage device, used to monitor and manage the device. The central control module can monitor information such as the energy storage device's current, voltage, power, state of charge, or temperature. For instance, it can control the charging and discharging current and voltage of the energy storage device. As an example, the central control module includes modules such as an Insulation Monitoring Module (IMM), a Master Battery Management Unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0064] As an example, a fire protection system includes control panels, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in energy storage systems.

[0065] As an example, the power distribution unit can be used to distribute power to the power modules of the energy storage device.

[0066] Currently, energy storage devices used to store electrical energy are usually installed in groups of multiple devices. When the battery pack in one of the energy storage devices experiences thermal runaway and causes a fire, the large amount of heat released inside will be transferred to adjacent energy storage devices. This heat will then affect the battery packs inside the adjacent energy storage devices through the thermal conduction of the outer casings of the adjacent energy storage devices, thereby causing thermal runaway of the battery packs in the adjacent energy storage devices and leading to the further spread of the fire.

[0067] To reduce the rate of heat transfer, this application provides an energy storage device, which includes an outer casing, a heat insulation layer, and a flame-retardant structure. The outer casing has a housing space for housing a battery device. The heat insulation layer is made of heat insulation material. The heat insulation layer is disposed on the wall of the outer casing and located on the side of the wall facing the housing space and / or the heat insulation layer is disposed between at least two walls of the outer casing, with the walls supporting the heat insulation layer. The flame-retardant structure is located inside the heat insulation layer and / or the flame-retardant structure is located on the side of the heat insulation layer facing the housing space.

[0068] In the above technical solution, by setting a heat insulation layer and a flame-retardant structure, the heat transfer rate is slowed down, and when thermal runaway of the energy storage device occurs, the time for temperature to be transferred to the adjacent energy storage device is extended; when the outer casing wall is a single-layer structure, the heat insulation layer is set on the outer casing wall and located on the side of the wall facing the containment space; when the outer casing wall is a multi-layer structure, a hollow structure is formed between the multi-layer structures, and the heat insulation layer is set in the hollow structure between at least two layers of walls.

[0069] By using a wall-supported insulation layer, there is no need to set up a support structure for the insulation layer, which saves internal space of the energy storage device and reduces the cost of the support structure.

[0070] The energy storage device described in this application can be an energy storage container or an energy storage cabinet, and it can be applied to an energy storage system. The energy storage system can include one or more energy storage devices and a power conversion system (PCS). The power conversion system is used to connect the power generation equipment and the energy storage device. The power generation equipment generates electrical energy, which can be stored in the energy storage device through the power conversion system. For example, the power generation equipment can specifically be a solar panel, hydroelectric power generation equipment, thermal power generation equipment, wind power generation equipment, etc.

[0071] The energy storage device and energy storage system according to embodiments of the present invention are described below with reference to Figures 1-5.

[0072] Referring to Figures 1-5, in a first aspect, embodiments of the present invention provide an energy storage device 100, including an outer casing 10, a heat insulation layer 20, and a flame-retardant structure 30. The outer casing 10 has an internal space for housing a battery device. The heat insulation layer 20 is made of heat insulation material. The heat insulation layer 20 is disposed on the wall 13 of the outer casing 10 and located on the side of the wall 13 facing the housing space and / or the heat insulation layer 20 is disposed between at least two layers of the outer casing 10 walls 13, and the walls 13 support the heat insulation layer 20. The flame-retardant structure 30 is located inside the heat insulation layer 20 and / or the flame-retardant structure 30 is located on the side of the heat insulation layer 20 facing the housing space.

[0073] The outer casing 10 has a hollow structure, forming a receiving space that can be used to house the battery pack in the energy storage device 100. The battery pack is a module in the energy storage device 100 used to store or provide energy. The outer casing 10 provides physical protection, environmental control, and system integration support for the battery pack, ensuring the operation of the battery pack from multiple dimensions and improving its service life and performance stability.

[0074] The outer casing 10 features a waterproof, dustproof, and corrosion-resistant sealed design, effectively isolating it from rainwater, snow, sand, salt spray, and industrial dust, reducing the possibility of short circuits at battery contacts and cell corrosion due to moisture. The outer casing 10 is primarily made of high-strength carbon steel or aluminum alloy, possessing resistance to ultraviolet radiation and high / low temperature aging, adapting to extreme outdoor temperature environments ranging from -40℃ to 60℃. The outer casing 10's structure is reinforced to withstand impacts from vehicle collisions, heavy object impacts, earthquakes, typhoons, and other external forces, reducing the risk of battery casing damage, cell deformation, and short circuits. Some outer casings 10 are also equipped with anti-pry locks and security monitoring to prevent vandalism or theft.

[0075] The outer casing 10 can be a single-layer structure or a multi-layer structure. When the outer casing 10 is a single-layer structure, it includes one wall 13, and the heat insulation layer 20 is disposed on the wall 13 and located on the side of the wall 13 facing the receiving space. When the outer casing 10 is a multi-layer structure, it includes at least two walls 13, forming a hollow structure between the at least two walls 13, and the heat insulation layer 20 is disposed in the hollow structure between the at least two walls 13.

[0076] Referring to Figure 1, the outer casing 10 may include a support 11 and a plate 12. The plate 12 is mounted on the support 11. The support 11 is used to enhance the structural strength of the outer casing 10, and the plate 12 is used to form a wall 13. In an optional embodiment, both the support 11 and the plate 12 can form a wall 13. The wall 13 directly supports the insulation layer 20, reducing the space occupied by the support structure when the insulation layer 20 is installed, saving internal space of the outer casing 10, and improving the utilization rate of the storage space and the miniaturization of the energy storage device 100.

[0077] The insulation layer 20 is made of insulation material and is used to reduce the rate of heat transfer.

[0078] In the above technical solution, by setting the heat insulation layer 20 to slow down the heat transfer rate, when thermal runaway of the energy storage device 100 occurs, the time for temperature to be transferred to the adjacent energy storage device 100 is extended; the heat insulation layer 20 is supported by the wall 13, eliminating the need for a separate support structure for the heat insulation layer 20, saving internal space of the energy storage device 100 and reducing the cost of the support structure; by setting the flame retardant structure 30 inside the heat insulation layer 20 and / or on the side of the heat insulation layer 20 facing the containment space, the heat insulation performance of the energy storage device 100 can be improved. The flame retardant structure 30 can be set with different structures according to different usage scenarios to improve the flame retardancy of the energy storage device 100.

[0079] Please refer to Figure 2. In some embodiments, the insulation layer 20 is a multi-layer composite structure, and the insulation layer 20 includes materials with at least two fire resistance ratings.

[0080] The core principle of combining materials with different fire resistance ratings is to utilize the complementary fire resistance properties of each material to construct a "layered protection, synergistic fire resistance" fire-resistant system. Ultimately, this achieves overall fire resistance performance superior to that of a single material, meeting the requirements of the application scenario for fire resistance duration, insulation, and anti-collapse. In a fire, it delays flame spread and structural failure, and reduces heat transfer. Materials with different fire resistance ratings differ in their fire resistance mechanisms, fire resistance limits, and high-temperature performance; combining them can compensate for each other's weaknesses. The core characteristic of high-fire-resistance materials is maintaining strength and not collapsing at high temperatures, with a fire resistance limit exceeding 3 hours, but their insulation may be weaker. The core characteristic of materials with medium fire resistance ratings is low thermal conductivity, enabling them to block heat transfer, but their own load-bearing capacity may be poor. The core characteristic of low-fire-resistance materials is expansion upon contact with fire, sealing gaps and preventing flame penetration, but they may be suitable for localized sealing.

[0081] The thermal insulation effect of the multi-layer composite insulation layer 20 can be calculated using the series thermal resistance of the multi-layer materials. The thermal resistance of a single refractory material... Where: R is the thermal resistance, L is the material thickness; λ is the thermal conductivity of the material; and A is the cross-sectional area in the direction of heat flow. The total thermal resistance of the multi-layer composite insulation layer 20 is... , , as well as These represent the thermal resistance of each layer of refractory material.

[0082] In the above technical solution, the insulation layer 20 includes at least two fire-resistant materials, which can reduce the thickness of the insulation layer 20, reduce the cost of the insulation layer 20, and save internal space of the energy storage device 100 while achieving the same insulation performance.

[0083] In some embodiments, at least two fire-resistant materials are arranged along the thickness direction of the wall 13, and along the direction from the outside of the outer casing 10 to the receiving space, the fire resistance of the fire-resistant materials decreases or decreases from both sides to the center.

[0084] Please refer to Figure 2. Taking three fire-resistant materials as an example, the fire resistance rating of the insulation layer 20 decreases from the outside to the inside. The insulation layer 20 includes a first insulation layer 21, a second insulation layer 22, and a third insulation layer 23. The fire resistance rating of the first insulation layer 21 is greater than that of the second insulation layer 22, and the fire resistance rating of the second insulation layer 22 is greater than that of the third insulation layer 23. The outer layer uses the first insulation layer 21 to directly block the flame from contacting the inner layer material and prevent the fire from spreading; the middle layer uses the second insulation layer 22 to block heat transfer and prevent the inner structure from failing due to high temperature; the inner layer uses the third insulation layer 23 to meet the load-bearing requirements and ensure the overall structural stability.

[0085] When the refractory material's refractory rating decreases from the sides towards the center, the outer refractory material prevents external flames from contacting the middle layer material, while the inner refractory material prevents internal flames from contacting the middle layer material.

[0086] In the above technical solution, by placing a material with a high fire resistance rating on the outside of the wall 13, when thermal runaway occurs, the material with a high fire resistance rating can effectively control and reduce the heat transfer rate when heat enters the energy storage device 100 from the outside or from the inside of the energy storage device 100 to the outside.

[0087] In some embodiments, the heat insulation material of the heat insulation layer 20 is at least one of ceramic fiber, mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam.

[0088] In the above technical solutions, materials such as ceramic fiber, nano aerogel, mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam all have porous structures, which can significantly block heat transfer and convective heat transfer, and have low thermal conductivity; they have strong heat insulation effect at the same thickness, and can reduce the thickness of the heat insulation layer by 20%; the above materials have stable chemical properties, are moisture-resistant, and are not prone to aging; they have low density and are convenient to construct and use.

[0089] In some embodiments, the insulation layer 20 is fixed to the wall 13.

[0090] In the above technical solution, the fixing method can prevent the insulation layer 20 from shifting, falling off, or delaminating due to vibration or equipment operation. Loosening will create gaps or air gaps, which will form convection heat transfer channels and reduce insulation efficiency. The fixing method ensures that the insulation layer always covers the entire wall 13 surface, preventing localized overheating caused by "exposed areas".

[0091] In some embodiments, an adhesive layer formed of glue is provided between the heat insulation layer 20 and the wall 13.

[0092] In the above technical solution, the heat insulation layer 20 is fixed to the wall 13 by adhesive bonding, which is convenient to operate and the wall 13 can support the heat insulation layer 20 without the need for other fixing structures, thereby reducing the thickness between the heat insulation layer 20 and the wall 13 and saving the internal space of the energy storage device 100.

[0093] In some embodiments, the insulation layer 20 is fixed to the wall 13 by fasteners.

[0094] Fasteners can be bolts or screws.

[0095] In the above technical solution, the insulation layer is fixed to the wall by fasteners, which facilitates the installation and removal of the insulation layer. When the outer casing is damaged, the insulation layer can be removed from the outer casing by removing the fasteners, and the insulation layer can be reused.

[0096] In some embodiments, the insulation layer 20 is located between at least two walls 13, and the insulation layer 20 rests against or is sandwiched between the two walls 13.

[0097] In the above technical solution, the heat insulation layer 20 is supported or clamped between the two walls 13. The heat insulation layer 20 is easy to install and does not require other fixing structures. This reduces the thickness between the heat insulation layer 20 and the wall 13, saving the internal space of the energy storage device 100.

[0098] As shown in Figure 3, in some embodiments, the flame-retardant structure 30 is a cooling pipe that can store or circulate coolant.

[0099] When the cooling pipe does not have an outlet, it stores coolant, which regulates the temperature of the wall 13 and the internal containment space of the outer casing 10. When the temperature of the wall 13 and / or the containment space rises, the coolant absorbs heat; when the temperature of the wall 13 and / or the containment space decreases, the coolant releases heat. In some embodiments, the coolant is water. When the cooling pipe has an outlet, it can spray coolant through the outlet for cooling and fire suppression. When the cooling pipe is positioned between multiple layers of wall 13, at least two layers of wall 13 are bonded together with a layer of aerogel, and a water-cooled pipe is positioned between the aerogel layers, with the water-cooled pipe closely attached to the wall 13 near the containment space.

[0100] In the above technical solution, by setting the flame-retardant structure 30 as a cooling pipe, when the temperature of the wall 13 of the energy storage device 100 rises, the coolant in the cooling pipe can absorb heat, reduce the temperature of the wall 13, and delay the spread of heat to the containment space; when the energy storage device 100 is running in extremely cold regions or deserts, the coolant inside the cooling pipe can also play a role in regulating the internal temperature of the energy storage device 100.

[0101] In some embodiments, the wall 13 is provided with a spray hole, and the cooling pipe generates a liquid outlet hole or opens a liquid outlet hole when heated, and the liquid outlet hole communicates with the spray hole.

[0102] During the manufacturing process of the cooling pipe, a material that is easily decomposable is used in some parts of the cooling pipe beforehand. When the external ambient temperature of the cooling pipe reaches a preset value, the material decomposes to form an outlet hole, and the coolant inside the cooling pipe is sprayed out from the outlet hole.

[0103] In one optional embodiment, the cooling pipe is provided with a liquid outlet hole and a valve is provided at the liquid outlet hole. The temperature of the outer wall 130 or the temperature of the battery device in the housing space is collected by a sensor. When the temperature reaches a preset value, the valve opens and the coolant in the cooling pipe is sprayed out from the liquid outlet hole.

[0104] In the above technical solution, when the temperature of the wall 13 or the battery device rises to the preset temperature, the coolant in the cooling pipe is sprayed out through the outlet hole and sprayed through the spray hole on the wall 13 to spray the inside and outside of the energy storage device 100, thereby reducing the temperature or extinguishing the fire.

[0105] As shown in Figure 4, in one optional embodiment, the flame-retardant structure 30 is a porous partition containing a thermally decomposable flame retardant.

[0106] When the ambient temperature of the flame-retardant structure 30 reaches a preset value, the thermally decomposable flame retardant decomposes to produce non-flammable gas. When the flame-retardant structure 30 is disposed between multiple layers of walls 13, the non-flammable gas fills the hollow structure formed by at least two layers of walls 13, preventing flame propagation. When the flame-retardant structure 30 is disposed on the side of the heat insulation layer 20 facing the receiving space, the non-flammable gas fills the receiving space where the battery device is installed, preventing flame propagation. The porous partition allows the generated non-flammable gas to escape in a timely manner.

[0107] In the above technical solution, by storing a thermally decomposable flame retardant in the porous partition, when the temperature generated by the thermal runaway of the adjacent energy storage device 100 spreads to the energy storage device 100, the thermally decomposable flame retardant will decompose to generate non-flammable gas and fill the containment space or the space between at least two layers of walls 13 of the outer casing 10, preventing the flame from spreading to the containment space.

[0108] In some embodiments, the thermally decomposable flame retardant is at least one of aluminum hydroxide and sodium bicarbonate.

[0109] Thermally decomposable flame retardants are in powder form, which accelerates the decomposition rate. They can be aluminum hydroxide powder, sodium bicarbonate powder, or a mixture of aluminum hydroxide and sodium bicarbonate powders.

[0110] In the above technical solution, aluminum hydroxide and sodium bicarbonate are used as decomposition-type flame retardants, which are environmentally friendly, have complementary flame retardant mechanisms, are widely applicable, and are low in cost. Both aluminum hydroxide and sodium bicarbonate are halogen-free flame retardants, and do not produce toxic and corrosive gases such as hydrogen halides or strong carcinogens such as dioxins during decomposition. The decomposition temperature of aluminum hydroxide is about 200~320℃, and the decomposition temperature of sodium bicarbonate is about 150~270℃. The decomposition temperatures of both exceed the ambient temperature, so they will not decompose and become ineffective before the preset temperature is reached. The flame retardant mechanism of aluminum hydroxide is that it absorbs a large amount of heat during decomposition, causing the temperature of wall 13 to drop. The generated Al2O3 will form a dense heat insulation layer 20 on the surface of wall 13, isolating oxygen and heat. When sodium bicarbonate decomposes, it releases a large amount of CO2 gas instantly, forming a "gas barrier" that quickly inhibits the spread of flame. The combination of aluminum hydroxide and sodium bicarbonate not only solves the problem of high dosage when aluminum hydroxide is used alone, but also makes up for the slight deficiency of the thermal stability of sodium bicarbonate, thus greatly improving the flame retardant efficiency.

[0111] As shown in Figure 5, in one optional embodiment, the flame-retardant structure 30 is a phase change layer, which is used to absorb heat.

[0112] The core principle of phase change materials (PCMs) in absorbing heat is to utilize the large amount of latent heat absorbed during the phase transition process, thereby storing or transferring heat while maintaining a relatively constant temperature throughout the process. PCMs have a fixed phase transition temperature. When the ambient temperature exceeds the phase transition temperature, the material begins to undergo a phase transition. Throughout the entire phase transition process, the material temperature remains stable at the phase transition point and does not rise with external heat input. Therefore, the temperature of the object being cooled can be precisely controlled, avoiding localized overheating.

[0113] The phase change layer can be paraffin, polyethylene glycol, or a ceramic-paraffin composite material.

[0114] The latent heat of phase change of paraffin can reach 180~250kJ / kg, which is much higher than that of ordinary inorganic salt PCM. It has a large energy storage density and high heat absorption / release efficiency. Polyethylene glycol is a food-grade material that is non-volatile and odorless, and will not pollute the environment even if it leaks. Ceramic-paraffin composite material is a composite phase change material that combines ceramic fillers with paraffin through physical compounding or chemical modification. It retains the high latent heat of paraffin and solves the problems of poor thermal conductivity and easy leakage.

[0115] In the above technical solution, when the flame-retardant structure 30 is a phase change layer, when the temperature generated by the thermal runaway of the adjacent energy storage device 100 spreads to the energy storage device 100, the phase change material reduces the heat entering the containment space through phase change heat absorption, thereby reducing the heat transfer rate.

[0116] In some embodiments, the exterior of the wall 13 is provided with a reflective coating or a mirror layer.

[0117] A reflective coating or mirror layer is applied to the top and side walls of the outer casing 10. This serves two purposes: firstly, it reflects the thermal radiation generated by the thermal runaway of adjacent energy storage devices 100; secondly, when sunlight shines on the top and side walls of the outer casing 10, the heat is effectively reflected away by the reflective coating or mirror layer, preventing a rise in the temperature of the energy storage device 100. This reduces the temperature of the energy storage device 100, decreases energy loss during cooling, and ultimately lowers its energy consumption. The reflective coating is a ceramic-based coating, using alumina ceramic or zirconia ceramic.

[0118] In the above technical solution, by setting a reflective coating or mirror layer on the outside of the wall 13, the reflective coating or mirror layer reflects heat, reducing the heat transferred to the inside of the energy storage device 100 and reducing the heat transfer rate.

[0119] Secondly, embodiments of the present invention provide an energy storage system, including: an energy storage device 100 according to a first aspect embodiment of the present invention.

[0120] In the above technical solution, the energy storage system includes an energy storage device 100 according to the first aspect of the present invention. By setting a heat insulation layer 20, the heat transfer rate is slowed down. When thermal runaway of the energy storage device 100 occurs, the time for temperature to be transferred to adjacent energy storage devices 100 is extended. When the wall 13 of the outer casing 10 is a single-layer structure, the heat insulation layer 20 is set on the wall 13 of the outer casing 10 and located on the side of the wall 13 facing the receiving space. When the wall 13 of the outer casing 10 is a multi-layer structure, a hollow structure is formed between the multi-layer structures. The heat insulation layer 20 is set in the hollow structure between at least two layers of walls 13. The heat insulation layer 20 is supported by the wall 13, eliminating the need for a separate support structure for the heat insulation layer 20, saving internal space of the energy storage device 100, and reducing the cost of the support structure.

[0121] The energy storage device 100 according to some embodiments of the present invention is described below with reference to Figures 1-5.

[0122] In this embodiment, the energy storage device 100 includes an outer casing 10, a heat insulation layer 20, and a flame-retardant structure 30. The outer casing 10 has an internal space for housing the battery device. The heat insulation layer 20 is made of heat-insulating material. The heat insulation layer 20 is disposed on the wall 13 of the outer casing 10 and located on the side of the wall 13 facing the housing space, and / or the heat insulation layer 20 is disposed between at least two walls 13 of the outer casing 10, with the walls 13 supporting the heat insulation layer 20. The flame-retardant structure 30 is located inside the heat insulation layer 20 and / or on the side of the heat insulation layer 20 facing the housing space. The flame-retardant structure 30 can reduce the temperature of the wall 13 or extinguish a fire.

[0123] The insulation layer 20 is a multi-layered composite structure, comprising materials of at least two fire resistance ratings. These materials of at least two fire resistance ratings are arranged along the thickness direction of the wall 13, decreasing in fire resistance from the outside of the outer casing 10 to the containment space, or decreasing from both sides towards the center. Referring to Figure 2, when there are three fire resistance ratings, the insulation layer 20 includes a first insulation layer 21, a second insulation layer 22, and a third insulation layer 23. The fire resistance rating of the first insulation layer 21 is greater than that of the second insulation layer 22, and the fire resistance rating of the second insulation layer 22 is greater than that of the third insulation layer 23. The outer layer uses the first insulation layer 21 to directly block flame contact with the inner layer materials, preventing the spread of fire; the middle layer uses the second insulation layer 22 to block heat transfer, preventing the inner structure from failing due to high temperatures; the inner layer uses the third insulation layer 23 to meet load-bearing requirements and ensure the overall structural stability. The insulation material of the insulation layer 20 is at least one of ceramic fiber, nano aerogel, mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam.

[0124] The exterior of wall 13 is provided with a reflective coating or a mirror layer. The reflective coating or mirror layer is applied to the top and side walls of the outer casing 10. On the one hand, it can reflect the thermal radiation generated by the thermal runaway of adjacent energy storage devices 100; on the other hand, when sunlight shines on the top and side walls of the outer casing 10, the heat can be effectively reflected away by the reflective coating or mirror layer.

[0125] The heat insulation layer 20 is fixed to the wall 13, and an adhesive layer formed by glue is provided between the heat insulation layer 20 and the wall 13, or the heat insulation layer 20 is fixed to the wall 13 by fasteners.

[0126] The insulation layer 20 may also be located between at least two walls 13, with the insulation layer 20 resting against or being sandwiched between the two walls 13.

[0127] Please refer to Figure 3. The flame-retardant structure 30 is a cooling pipe, which can store or circulate coolant. The wall 13 is provided with spray holes. When the cooling pipe is heated, it generates or opens the outlet hole, which is connected to the spray hole.

[0128] Please refer to Figure 4. The flame-retardant structure 30 is a porous partition. The porous partition stores a heat-decomposable flame retardant, which is at least one of aluminum hydroxide and sodium bicarbonate.

[0129] Please refer to Figure 5. The flame-retardant structure 30 is a phase change layer, which is used to absorb heat. The phase change layer can be paraffin wax, polyethylene glycol, or a ceramic-paraffin composite material.

[0130] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0131] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An energy storage device, characterized in that, include: An outer casing, the interior of which has a space for housing the battery device; a heat insulation layer, the heat insulation layer being made of heat insulation material; the heat insulation layer being disposed on the wall of the outer casing and located on the side of the wall facing the space and / or the heat insulation layer being disposed between at least two walls of the outer casing, the walls supporting the heat insulation layer; a flame-retardant structure, the flame-retardant structure being located inside the heat insulation layer and / or the flame-retardant structure being located on the side of the heat insulation layer facing the space.

2. The energy storage device according to claim 1, characterized in that, The insulation layer is a multi-layer composite structure, and the insulation layer includes materials with at least two fire resistance ratings.

3. The energy storage device according to claim 2, characterized in that, At least two fire-resistant materials are arranged along the thickness direction of the wall, and the fire resistance of the fire-resistant materials decreases from the outside of the outer casing to the receiving space or decreases from both sides to the center.

4. The energy storage device according to claim 1, characterized in that, The insulation material of the insulation layer is at least one of ceramic fiber, mineral wool, aluminum silicate felt, rock wool, phenolic foam, aerogel, polyurethane foam, and polystyrene foam.

5. The energy storage device according to claim 1, characterized in that, The heat insulation layer is fixed to the wall.

6. The energy storage device according to claim 5, characterized in that, An adhesive layer formed by glue is provided between the heat insulation layer and the wall, or the heat insulation layer is fixed to the wall by fasteners.

7. The energy storage device according to claim 1, characterized in that, The insulation layer is located between at least two of the walls, and the insulation layer rests against or is sandwiched between the two walls.

8. The energy storage device according to claim 1, characterized in that, The flame-retardant structure is a cooling pipe, which can store or circulate coolant.

9. The energy storage device according to claim 8, characterized in that, The wall is provided with a spray hole, and the cooling pipe generates a liquid outlet hole or opens a liquid outlet hole when heated, and the liquid outlet hole is connected to the spray hole.

10. The energy storage device according to claim 1, characterized in that, The flame-retardant structure is a porous partition, and the porous partition stores a heat-decomposing flame retardant.

11. The energy storage device according to claim 10, characterized in that, The heat-decomposable flame retardant is at least one of aluminum hydroxide and sodium bicarbonate.

12. The energy storage device according to claim 1, characterized in that, The flame-retardant structure is a phase change layer, which is used to absorb heat.

13. The energy storage device according to claim 12, characterized in that, The phase change layer is made of paraffin, polyethylene glycol, or a ceramic-paraffin composite material.

14. The energy storage device according to any one of claims 1-13, characterized in that, The exterior of the wall is provided with a reflective coating or a mirror layer.

15. An energy storage system, characterized in that, include: The energy storage device according to any one of claims 1-14.

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