CN116544555A - Energy storage device and energy storage system - Google Patents

Abstract

The embodiment of the application provides an energy storage device and energy storage system, this energy storage device includes header tank, battery capsule, battery and spray set, wherein: the battery capsule is used for accommodating a battery, and is filled with a first cooling medium which is used for cooling the battery; the liquid collecting box is used for accommodating the battery capsules; the spraying device is positioned above the top surface of the battery capsule and is used for spraying the second cooling medium to the outer surface of the top surface of the battery capsule. According to the energy storage device and the energy storage system, the heat dissipation effect and the temperature uniformity of the battery can be improved, and particularly the problem of high-temperature hot spots of the electrode lugs can be effectively solved.

Description

Energy storage device and energy storage system

Technical Field

The embodiment of the application relates to the technical field of energy sources, in particular to an energy storage device and an energy storage system.

Background

New energy replaces traditional fossil energy, which is key to achieving the aim of double carbon, and energy transformation changes the traditional energy pattern, so as to promote the rapid development of electric automobiles and energy storage industries. However, the charge and discharge efficiency, capacity, safety and life of a lithium battery are greatly affected by temperature, and too high and too low temperatures or a large temperature difference between battery packs can directly affect the performance of the lithium battery, so that a battery system fails too early and even causes a series of accidents such as fire, explosion and the like. To improve the performance and safety of the battery pack, the battery needs to be provided with a thermal management system.

At present, an indirect contact type liquid cooling (namely cold plate type liquid cooling) mode is often adopted to cool a battery, namely, the liquid cooling plate is attached to the wall surface of a battery module through a heat conducting medium, heat generated by the battery is transferred to a cooling working medium in the liquid cooling plate through the heat conducting medium, and then the heat is taken away through the flowing cooling working medium. When the indirect contact type liquid cooling mode is adopted to cool the battery, larger heat transfer thermal resistance exists between the battery module and the liquid cooling plate, the heat exchange area of the battery module and the liquid cooling plate is limited, and the high heating parts such as the battery tab cannot be directly cooled, so that the temperature of the battery tab is higher, and the overall temperature uniformity of the battery is poor.

Disclosure of Invention

The embodiment of the application provides an energy storage device and an energy storage system, which can improve the heat dissipation effect and the temperature uniformity of a battery.

In a first aspect, an energy storage device is provided, the energy storage device includes a header tank, a battery capsule, a battery and a spray device, wherein: the liquid collecting box is used for accommodating the battery capsules; the battery capsule is used for accommodating the battery, and is filled with a first cooling medium which is used for cooling the battery; the spraying device is located above the top surface of the battery capsule and is used for spraying a second cooling medium to the outer surface of the top surface of the battery capsule.

In this application embodiment, when the battery produced the heat, can with heat transfer to the first cooling medium of battery direct contact, after the first cooling medium absorbed the heat that the battery produced, through heat conduction, heat convection or boiling heat transfer's mode with the heat transfer of battery production to the battery capsule, the battery capsule carries out the secondary heat transfer through the mode of convection heat transfer with the second cooling medium that spray set sprayed, and the heat can be taken out the header tank by the second cooling medium of flow. On one hand, the battery exchanges heat with the first cooling medium in a direct contact mode, and has smaller heat transfer resistance, so that the heat dissipation effect of the battery can be effectively improved; on the other hand, the contact area between the first cooling medium and the battery is large, and the first cooling medium can contact with a part with higher heating value (such as a battery tab), so that the temperature uniformity of the battery can be improved by increasing the heat exchange area.

With reference to the first aspect, in certain implementation manners of the first aspect, the header tank includes a top surface, a side surface, and a bottom surface, and the side surface of the header tank is provided with at least one liquid inlet and at least one liquid outlet, the liquid inlet is in communication with the spraying device, and the second cooling medium flows into the spraying device through the liquid inlet; the second cooling medium flows out of the liquid collecting box through the liquid outlet.

In this application embodiment, the second cooling medium flows into the header tank from the inlet, exchanges heat with the battery capsule, and then flows out from the liquid outlet of the header tank, that is to say, the second cooling medium is circulated, so that heat can be brought out of the header tank through the circulation flow of the second cooling medium, and the purpose of heat dissipation of the battery is achieved.

With reference to the first aspect, in certain implementations of the first aspect, the liquid outlet is above a bottom surface of the battery capsule and below a top surface of the battery capsule. That is, the lowest point of the liquid outlet is higher than the bottom surface of the battery capsule, and the highest point of the liquid outlet is lower than the top surface of the battery capsule.

In this embodiment, the second cooling medium may partially or completely submerge the side surface of the battery capsule by providing the liquid outlet higher than the bottom surface of the battery capsule and lower than the top surface of the battery capsule. Thus, when the battery is in operation and generates heat, the surrounding first cooling medium can absorb heat generated by the battery and is conducted to the outer surface of the battery capsule through the first cooling medium; the second cooling medium is sprayed out by a spraying device positioned above the top surface of the battery capsule, the top surface of the battery capsule is cooled in a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule, the side surface of the battery capsule can be cooled in a falling film or immersed mode, and finally heat is brought out of a liquid collecting box through the circulating flow of the second cooling medium, so that continuous heat dissipation of the battery is realized.

In some embodiments, the distance between the lowest point of the liquid outlet and the bottom surface of the battery capsule is less than a first threshold value, which may be set according to the bottom wall thickness of the liquid collection tank.

In this case, it can be considered that no or only a small amount of the second cooling medium is in contact with the side of the battery capsule. Thus, when the battery is in operation and generates heat, the surrounding first cooling medium can absorb heat generated by the battery and is conducted to the outer surface of the battery capsule through the first cooling medium; the second cooling medium is sprayed out by a spraying device above the top surface of the battery capsule, the top surface of the battery capsule is cooled by a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule, the film is lowered under the action of gravity, and heat is taken away with the side surface of the battery capsule by a convection heat exchange mode. The heat dissipation mode of the top jet flow and the side falling film cooling can effectively improve the convective heat transfer coefficient of the second cooling medium and the outer surface of the battery capsule, thereby improving the overall heat dissipation effect of the battery.

In other embodiments, the lowest point of the liquid outlet is higher than the side surface of the battery capsule and lower than the top surface of the battery capsule.

In this case, the side of the battery capsule can be considered immersed in the second cooling medium. Thus, when the battery is operated to generate heat, the surrounding first cooling medium absorbs heat generated by the battery and is conducted to the outer surface of the battery capsule through the first cooling medium; the second cooling medium is sprayed out by the spraying device above the top surface of the battery capsule, the top surface of the battery capsule is cooled in a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule, after the second cooling medium is injected for a period of time, the side surface of the battery capsule can be immersed in the second cooling medium, so that the top surface jet flow and side surface immersed heat dissipation mode can be realized, heat is brought out of the liquid collecting box through the circulating flow of the second cooling medium, and continuous heat dissipation of the battery is realized.

With reference to the first aspect, in certain implementations of the first aspect, the liquid outlet is higher than a top surface of the battery capsule. That is, the top surface of the battery capsule is positioned between the highest point of the liquid outlet and the lowest point of the liquid outlet. In this case, the battery capsule may be considered to be fully submerged in the second cooling medium, i.e. both the top and side surfaces of the battery capsule are submerged in the second cooling medium.

In this embodiment, the second cooling medium may completely submerge the battery capsule by setting the height of the liquid outlet higher than the height of the top surface of the battery capsule. Thus, when the battery is operated to generate heat, the surrounding first cooling medium absorbs heat generated by the battery and is conducted to the outer surface of the battery capsule through the first cooling medium; the second cooling medium is sprayed out by the spraying device above the top surface of the battery capsule, the top surface of the battery capsule is cooled in a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule, after the second cooling medium is injected for a period of time, the battery capsule can be completely immersed in the second cooling medium, so that the heat dissipation mode of the top surface and the side surface immersion can be realized, and heat is brought out of the liquid collecting box through the circulating flow of the second cooling medium, so that the continuous heat dissipation of the battery is realized.

With reference to the first aspect, in certain implementations of the first aspect, an inner surface of the battery capsule is provided with a heat dissipation fin for increasing a contact area of the first cooling medium with the inner surface of the battery capsule.

In the embodiment of the application, the heat dissipation fins are arranged on the inner surface of the battery capsule, so that the contact area between the first cooling medium and the inner surface of the battery capsule can be increased, the heat transfer effect of the first cooling medium and the outer surface of the battery capsule can be enhanced, and the cooling of the first cooling medium is accelerated.

In one possible implementation, the top surface of the battery capsule is an arc surface, and the side surface of the battery capsule is perpendicular to the bottom surface of the battery capsule.

It will be appreciated that when the top surface of the battery capsule is provided as an arc surface and the side surface of the battery capsule is perpendicular to the bottom surface of the battery capsule, the spraying device may spray the second cooling medium along the arc top surface of the battery capsule, i.e. cool the top surface of the battery capsule by means of a jet flow, and then the second cooling medium may flow to the side surface of the battery capsule, under the action of gravity, down along the side surface of the battery capsule, i.e. cool the side surface of the battery capsule by means of a side falling film. Specifically, by setting the top surface of the battery capsule to be an arc surface, a certain space can be reserved for the first cooling medium in the gas phase; under the action of jet impact, the top surface of the battery capsule exchanges heat with fluid by a higher convection heat exchange coefficient, so that a better heat dissipation effect is realized; the side of battery capsule carries out heat transfer with higher convection heat transfer coefficient under the effect of falling film cooling, realizes better radiating effect. In addition, the distance between the side face of the battery capsule and the battery is relatively small, the space occupied by the battery capsule is relatively small, and the space utilization rate is high.

In another possible implementation, the top surface and the side surface of the battery capsule are both arc surfaces.

It should be understood that when the top and side surfaces of the battery capsule are both arc surfaces, the spraying device may spray the second cooling medium along the arc top and side surfaces of the battery capsule, i.e., cool the top and side surfaces of the battery capsule by means of a jet. The jet flow area can be increased by the arc-shaped top surface and the arc-shaped side surface, and the fluid flow speed of the top surface and the arc-shaped side surface of the battery capsule is high, so that heat exchange is performed between the fluid and the outer surface of the battery capsule by using a higher convection heat exchange coefficient, and a good heat dissipation effect is achieved. In addition, as the top surface and the side surface of the battery capsule are both arc surfaces, the height of the spraying device is increased, and the distance between the side surface of the battery capsule and the battery is relatively large, so that the space occupied by the battery capsule is relatively large.

In yet another possible implementation, the battery capsule is of a cubic or cuboid structure.

It should be appreciated that when the battery capsule is configured in a cube or cuboid configuration, the second cooling medium sprayed by the spray device may flow down the cube or cuboid battery capsule, over the top and side surfaces of the battery capsule, and may carry heat transferred to the outer surface of the battery capsule out of the header tank. When the second cooling medium flows along the battery capsule, compared with the first two implementation modes, the heat exchange area of the second cooling medium and the battery capsule is increased, and the heat exchange effect can be ensured to a certain extent.

With reference to the first aspect, in certain implementations of the first aspect, the battery is partially or fully immersed in the first cooling medium.

In this application embodiment, first cooling medium can submergence battery tab to can dispel the heat to battery tab, can solve the unable problem of effectively cooling battery tab, avoid the difference in temperature too big between battery tab and the core.

With reference to the first aspect, in certain implementations of the first aspect, the battery capsule is a fully sealed structure.

In this application embodiment, through setting up battery capsule for full seal structure, can guarantee the gas tightness of cavity, reduce gaseous phase working medium and leak the risk. Meanwhile, by means of top surface jet flow and side surface falling film, condensation of the first cooling medium can be accelerated, extrusion deformation of the battery due to overlarge air pressure inside the battery capsule is avoided, and the problem that pressure balance inside the battery capsule is difficult to control is solved.

With reference to the first aspect, in certain implementations of the first aspect, the battery includes, but is not limited to, any of the following types: square battery, cylindrical battery, soft package battery.

In this application embodiment, the first cooling medium can be through heat conduction, heat convection or boiling heat transfer's mode with the heat transfer that the battery produced to battery capsule internal surface, and battery capsule internal surface passes through heat conduction with heat transfer to battery capsule surface, and battery capsule surface contacts with the second cooling medium that sprays, passes through heat transfer's mode with heat transfer to the second cooling medium, and the second cooling medium that is recirculated flow takes out the header tank to reach the purpose that reduces battery temperature.

With reference to the first aspect, in certain implementation manners of the first aspect, the first cooling medium is an insulating cooling medium, for example, may be an oil cooling medium or a fluorinated liquid cooling medium, and the second cooling medium includes any one of the following: glycol aqueous solution, nano fluid and phase change emulsion.

Since the first cooling medium is in direct contact with the battery, the first cooling medium is an insulating cooling medium. That is, the first cooling medium may be a single-phase insulating cooling medium or a two-phase insulating cooling medium. The second cooling medium may comprise all types of cooling medium, that is, the second cooling medium may be an insulating cooling medium or a non-insulating cooling medium. Illustratively, the second cooling medium may be: oils, fluorinated fluids, aqueous ethylene glycol solutions, nanofluids, phase-change emulsions, and the like, as not limited in this application.

In one possible implementation, the first cooling medium may be a single-phase insulating cooling medium (e.g., oil). The single-phase insulating cooling medium can transfer the heat of the battery to the inner surface of the battery capsule through heat conduction and heat convection, the inner surface of the battery capsule can transfer the heat to the outer surface of the battery capsule through heat conduction, the outer surface of the battery capsule is contacted with the second cooling medium, the heat is transferred to the second cooling medium through heat convection, and the circulated second cooling medium is taken out of the liquid collecting box.

In another possible implementation, the first cooling medium may be a two-phase insulating cooling medium (e.g., a fluorinated liquid). The heat generated by the battery can be taken away by heat conduction, heat convection and boiling heat exchange between the two-phase insulating cooling medium and the surface of the battery. Specifically, when the medium-term temperature is low before the battery is charged and discharged, the first cooling medium absorbs heat generated by the battery in a heat conduction and heat convection mode; when the temperature of the battery reaches the phase transition temperature of the first cooling medium, the first cooling medium boils and absorbs a large amount of heat generated by the battery; the first cooling medium in gas phase moves to the top surface of the battery capsule under the action of molecular heat movement and exchanges heat with the top surface of the battery capsule in a heat conduction and heat convection mode; the top surface of the battery capsule exchanges heat with a second cooling medium sprayed out of the spraying device in a convection heat exchange mode, indirectly absorbs the heat of the first cooling medium, and brings the heat out of the liquid collecting box through circulating flow; the cooled first cooling medium is condensed and then flows back into the battery capsule, and the high-efficiency heat dissipation of the battery is realized by circulating and reciprocating.

With reference to the first aspect, in certain implementations of the first aspect, the spray device is fixed to an outside of a top surface of the battery capsule, or the spray device is fixed to an inside of a top surface of the header tank.

In one possible implementation manner, the spraying device comprises a main pipe, a plurality of spraying points are arranged on the main pipe, the spraying device comprises a first spraying point, a first branch pipe and a second branch pipe are arranged on the first spraying point, the first branch pipe can be arranged along a first direction, the second branch pipe can be arranged along a second direction, the first direction and the second direction face the top surface of the battery capsule, and the first direction and the second direction are arranged at an included angle. It should be understood that the first spraying point may be one point located on the main pipe, or may be a point located on two walls of the main pipe.

In another possible implementation manner, the spraying device includes a main pipe, a plurality of spraying points are arranged on the main pipe, the spraying points include a first spraying point, a first branch pipe and a second branch pipe are arranged on the first spraying point, the first branch pipe and the second branch pipe can be arranged along a third direction, and the third direction is parallel to the top surface of the battery capsule. It should be understood that the first spraying point may be one point located on the main pipe, or may be a point located on two walls of the main pipe.

In a second aspect, there is provided an energy storage system comprising: the energy storage device of any one of the first aspect and the first aspect; and the heat dissipation loop is used for cooling the second cooling medium.

In one possible implementation, the heat dissipation loop includes a valve for controlling a flow rate of the second cooling medium in the energy storage system, a water pump for providing circulating power of the second cooling medium in the energy storage system, a flow meter for measuring a flow rate of the second cooling medium in the energy storage system, a radiator for dissipating heat of the second cooling medium, and a pipe system for connecting the valve, the water pump, the flow meter, and the radiator.

In this application embodiment, when the battery produces heat, can with the heat transfer to the first cooling medium of battery direct contact, first cooling medium can with the heat transfer of battery to the battery capsule, spray set can spray the second cooling medium to the battery capsule to can with heat transfer to the second cooling medium, dispel the heat by the second cooling medium, and the outside of second cooling medium can circulation flow to the header tank, dispel the heat to the second cooling medium through the radiator, thereby can give off the heat that the battery produced in the atmosphere environment.

In one possible implementation, the energy storage system performs at least one of the following operations in response to the temperature of the battery being above a first threshold: increasing the opening degree of the valve, increasing the power of the water pump and increasing the running power of the radiator.

In this implementation, when the battery temperature is higher than a certain threshold, the heat dissipation capability of the energy storage system needs to be enhanced, so the flow rate of the second cooling medium can be increased by increasing the opening degree of the valve, or the circulation speed of the second cooling medium can be increased by increasing the power of the water pump, or the heat dissipation efficiency of the second cooling medium can be increased by increasing the operation power of the radiator.

In another possible implementation, the energy storage system performs at least one of the following in response to the temperature of the battery being below a first threshold: the opening degree of the valve is reduced, the power of the water pump is reduced, and the running power of the radiator is reduced.

In this implementation, when the battery temperature is below a certain threshold, the heat dissipation capacity of the energy storage system needs to be reduced to reduce the system power consumption, the flow rate of the second cooling medium may be reduced by reducing the opening of the valve, or the circulation speed of the second cooling medium may be reduced by reducing the power of the water pump, or the heat dissipation efficiency of the second cooling medium may be reduced by reducing the operating power of the radiator.

Drawings

Fig. 1 is a schematic structural diagram of an energy storage device according to an embodiment of the present application.

Fig. 2 is a schematic diagram of an internal structure of a battery capsule according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 5 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 6 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 7 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 8 is a schematic structural diagram of another energy storage device according to an embodiment of the present disclosure.

Fig. 9 is a schematic structural diagram of a spraying device according to an embodiment of the present application.

Fig. 10 is a schematic structural diagram of another spraying device according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of an energy storage system according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

In order to facilitate understanding of the embodiments of the present application, the following description is made before describing the embodiments of the present application.

In the present embodiments, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first", "second" may include one or more features judiciously or implicitly. In addition, in the description of the embodiments of the present application, "plurality" means two or more, and "at least one" and "one or more" mean one, two or more. The singular expressions "a", "an", "the" and "the" are intended to include, for example, also "one or more" such expressions, unless the context clearly indicates the contrary.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

In the description of the embodiments of the present application, the terms "upper," "lower," "inner," "outer," "vertical," and the like indicate an orientation or positional relationship defined with respect to the orientation or position in which the components in the drawings are schematically placed, and it should be understood that these directional terms are relative concepts used for relative description and clarity, rather than indicating or implying that the apparatus or component in question must have a particular orientation or be constructed and operated in a particular orientation, which may vary accordingly with respect to the orientation in which the components in the drawings are placed, and therefore should not be construed as limiting the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "connected," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be a mechanical connection; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those skilled in the art according to the specific circumstances.

The embodiments of the present application define the coordinate system of the drawings. In the coordinate system, the x direction, the y direction and the z direction intersect two by two. Wherein, x direction and y direction are the contained angle setting, and y direction and z direction are the contained angle setting, and z direction and x direction are the contained angle setting, and this contained angle can be approximately 90, for example can be 85 °, 90 °, 95 etc. this application does not limit. For ease of description and understanding, embodiments of the present application are described with respect to x-direction, y-direction, and z-direction being perpendicular to each other, e.g., the x-direction and y-direction may be parallel to the ground, and the z-direction may be perpendicular to the ground.

New energy replaces traditional fossil energy, which is key to achieving the aim of double carbon, and energy transformation changes the traditional energy pattern, so as to promote the rapid development of electric automobiles and energy storage industries. However, the charge and discharge efficiency, capacity, safety and life of a lithium battery are greatly affected by temperature, and too high and too low temperatures or a large temperature difference between battery packs can directly affect the performance of the lithium battery, so that a battery system fails too early and even causes a series of accidents such as fire, explosion and the like. To improve the performance and safety of the battery pack, the battery pack needs to be configured with a thermal management system.

The heat transfer mode mainly comprises heat conduction and convection heat exchange. Heat conduction refers to a manner of transferring heat along a solid object, where heat is transferred from a portion of the object having a higher temperature to a portion having a lower temperature along the object. Convective heat transfer refers to the manner in which heat is transferred by flowing heat in a gas or liquid.

Common convective heat transfer modes include jet heat transfer and boiling heat transfer. Jet refers to a flow pattern in which liquid is ejected from a nozzle or orifice, out of the constraints of a solid boundary. Jet heat exchange refers to heat transfer of liquid in a jet mode, jet heat exchange is one of convection heat exchange, and the jet heat exchange has heat exchange capacity. The heat exchange process of boiling heat exchange liquid when boiling on the heating surface is two-phase flow heat exchange with phase change characteristics, boiling heat exchange is one of convection heat exchange, the heat exchange coefficient of boiling heat exchange is larger, and the heat exchange capacity is stronger. The falling film means that the liquid flows from top to bottom in a film shape under the action of gravity along the wall surface of the container, and the liquid can absorb heat from the wall surface of the container in the falling film process.

At present, an indirect contact type liquid cooling (namely cold plate type liquid cooling) mode is often adopted for cooling a battery, namely, a liquid cooling plate is attached to the wall surface of a battery module through a heat conducting medium, heat generated by the battery is transferred to a cooling working medium in the cold plate through the heat conducting medium, and then the heat is taken away through the flowing cooling working medium. When indirect contact type liquid cooling is adopted for heat dissipation, larger heat transfer resistance exists between the battery module and the liquid cooling plate, so that the heat dissipation effect is limited, the heat exchange area of the battery module and the liquid cooling plate is limited, high heat-generating parts such as battery lugs cannot be directly cooled, the temperature of the battery lugs is higher, and the overall temperature uniformity of the battery is poor.

The immersion liquid cooling is a novel liquid cooling heat dissipation technology in recent years, and is to immerse a battery partially or wholly in an insulating cooling medium, and take away heat generated by the battery through convection heat exchange or two-phase boiling heat exchange. The immersed liquid cooling can obtain better heat dissipation effect by virtue of a larger heat exchange area and a higher heat exchange coefficient during two-phase boiling heat exchange. The immersed liquid cooling can improve the energy density of the battery by reducing the gap of the battery on one hand, and can improve the temperature uniformity of the battery by increasing the heat exchange area of the cooling liquid and the battery on the other hand.

The immersed liquid cooling comprises single-phase immersion and two-phase immersion, and in a single-phase immersion (for example, oil immersion) cooling system, the battery and the cooling liquid are mainly subjected to heat dissipation in a heat conduction and convection heat exchange mode; in a two-phase immersed (e.g., fluoride liquid immersed) cooling system, heat of the battery is taken away by the battery and the cooling liquid mainly through boiling heat exchange, and the convection heat exchange coefficient during boiling heat exchange is greatly improved, so that the heat dissipation effect is obviously improved compared with that of single-phase convection. In addition, the viscosity of the insulating cooling working medium in single-phase immersion is larger, and the power consumption of a pump for driving the consumption of the insulating cooling working medium is larger; however, the complexity of the system is higher during two-phase immersion, and the problems of leakage risk, pressure balance control in the cavity and the like exist after the working medium is vaporized.

Accordingly, embodiments of the present application provide an energy storage device and an energy storage system in an effort to solve the above-described problems.

Fig. 1 is a schematic structural diagram of an energy storage device according to an embodiment of the present application.

The energy storage device 100 may include a header tank 110, a battery capsule 120, a battery 130, and a spray device 140, wherein: the battery capsule 120 includes a top surface, side surfaces, and a bottom surface, the battery capsule 120 is configured to house the battery 130, and the battery capsule 120 is filled with a first cooling medium, and the first cooling medium is configured to cool the battery 130; the header tank 110 is used for accommodating the battery capsule 120; the spraying device 140 is located above the top surface of the battery capsule 120, and the spraying device 140 is used for spraying the second cooling medium to the top surface and the outer surface of the battery capsule 120.

It should be appreciated that the battery capsule 120 is internally filled with a first cooling medium, and the first cooling medium can partially or completely submerge the battery 130, so that the battery 130 can be cooled by the first cooling medium, i.e., the battery 130 can be cooled by submerged liquid cooling. The battery 130 may be replaced with other electronic devices, including but not limited to the following: servers, chips, power devices (e.g., energy storage ac (power conversion system, PCS)).

It should be noted that, since the first cooling medium is in direct contact with the battery 130, the first cooling medium is an insulating cooling medium. That is, the first cooling medium may be a single-phase insulating cooling medium (e.g., an oil-type cooling medium) or a two-phase insulating cooling medium (e.g., a fluorinated liquid-type cooling medium). The second cooling medium may comprise all types of cooling medium, that is, the second cooling medium may be an insulating cooling medium or a non-insulating cooling medium. Illustratively, the second cooling medium may be: oils, fluorinated liquids, aqueous ethylene glycol solutions, nanofluids, phase-change emulsions, and the like, which are not limited in this application.

It should be appreciated that the first cooling medium may transfer heat generated by the battery 130 to the inner surface of the battery capsule 120 by heat conduction, heat convection or boiling heat exchange, the inner surface of the battery capsule 120 transfers heat to the outer surface of the battery capsule 120 by heat conduction, the outer surface of the battery capsule 120 is in contact with the sprayed second cooling medium, heat is transferred to the second cooling medium by heat convection, and the circulated second cooling medium is carried out of the header tank 110 for the purpose of reducing the temperature of the battery 130. It should be noted that, in the energy storage device 100 provided in the embodiment of the present application, on one hand, the heat exchange is performed by the battery 130 and the first cooling medium in a direct contact manner, so that the heat transfer resistance is smaller, and therefore, the heat dissipation effect of the battery 130 can be effectively improved; on the other hand, the contact area between the first cooling medium and the battery 130 is large, and the first cooling medium can contact a portion with a high heat generation amount (such as a battery tab), so that the heat exchange area is increased to improve the temperature uniformity of the battery 130.

In some embodiments, the first cooling medium may be a single-phase insulating cooling medium (e.g., oil). The single-phase insulating cooling medium may transfer heat of the battery 130 to the inner surface of the battery capsule 120 by means of heat conduction and heat convection, the inner surface of the battery capsule 120 transfers heat to the outer surface of the battery capsule 120 by means of heat conduction, the outer surface of the battery capsule 120 is in contact with the second cooling medium sprayed by the spraying device 140, the heat is transferred to the second cooling medium by means of heat convection, and the circulated second cooling medium is then brought out of the header tank 110.

In other embodiments, the first cooling medium may be a two-phase insulating cooling medium (e.g., a fluorinated liquid). The heat generated by the battery 130 can be carried away by heat conduction, heat convection and boiling heat exchange between the two-phase insulating cooling medium and the surface of the battery. Specifically, when the medium-term temperature is low before the battery 130 is charged and discharged, the first cooling medium absorbs heat generated by the battery 130 by means of heat conduction and heat convection; when the temperature of the battery 130 reaches the phase transition temperature of the first cooling medium, the first cooling medium boils while absorbing a large amount of heat generated from the battery 130; the first cooling medium in the gas phase moves to the top surface of the battery capsule 120 under the action of molecular heat movement, and exchanges heat with the top surface of the battery capsule 120 by means of heat conduction and heat convection; the top surface of the battery capsule 120 exchanges heat with the second cooling medium sprayed by the spraying device 140 in a convection heat exchange mode, indirectly absorbs the heat of the first cooling medium, and brings the heat out of the liquid collecting tank 110 through circulating flow; the cooled first cooling medium is condensed and then flows back into the battery capsule 120, and the circulation is repeated to realize the efficient heat dissipation of the battery.

For example, the first cooling medium is a fluorinated liquid, when the temperature of the battery 130 reaches the phase transition temperature of the fluorinated liquid, the fluorinated liquid continuously absorbs heat of the battery 130, so that the fluorinated liquid can be subjected to phase transition (i.e. vaporization), and in the vaporization process, on one hand, the fluorinated liquid can absorb a large amount of heat, and on the other hand, the heat transfer coefficient between the fluorinated liquid and the surface of the battery 130 is obviously improved, so that the heat generated by the battery 130 can be taken away more rapidly, and therefore, the heat dissipation efficiency of the battery 130 can be improved. After the fluoridized liquid absorbs heat and turns into gas, the gas floats to the top surface of the battery capsule 120 in a molecular thermal motion mode, then exchanges heat with the top surface of the battery capsule 120 in a thermal conduction and thermal convection mode, the top surface of the battery capsule 120 and a second cooling medium sprayed out by the spraying device 140 indirectly take away the heat in the first cooling medium in a convection heat exchange mode, and after the first cooling medium is cooled, the first cooling medium is condensed into liquid and flows back into the battery capsule 120 under the action of gravity.

It should be noted that the first cooling medium may completely submerge the battery 130, that is, the liquid level of the first cooling medium may be higher than the height of the battery 130. The first cooling medium can submerge the battery tab to can dispel the heat to the battery tab, can solve the unable problem of effective cooling battery tab, avoid the too big difference in temperature between battery tab and the core.

In some embodiments, as shown in fig. 2, fig. 2 illustrates the internal structure of a battery capsule, and the battery capsule 120 may include at least one battery 130 or a plurality of closely arranged batteries 130 inside, with a gap between adjacent two rows of batteries, which may be filled with a first cooling medium. The battery 130 includes, but is not limited to, any of the following types: square battery, cylindrical battery, soft package battery. It should be appreciated that in the embodiments of the present application, the spacing between different cells is greatly reduced compared to the indirect contact cooling of the prior art, and both the battery pack energy density and the power density are significantly improved.

In some embodiments, the battery capsule 120 is a fully sealed structure. By providing the battery capsule 120 with a fully sealed structure, the air tightness of the cavity can be ensured, and the gas phase working medium leakage risk can be reduced. Meanwhile, by means of top surface jet flow and side surface falling film, condensation of the first cooling medium can be accelerated, extrusion deformation of the battery due to overlarge air pressure inside the battery capsule 120 is avoided, and the problem that pressure balance inside the battery capsule 120 is difficult to control is solved.

In the embodiment of the present application, the number of battery capsules 120 and the number of batteries 130 are not limited, and one or more battery capsules may be included in the present application, and one or more batteries may be included. In practice, the number of battery capsules may be adjusted according to the number of batteries, that is, the batteries may be placed in one capsule or in a plurality of different capsules.

Alternatively, as shown in fig. 2, the inner surface of the battery capsule 120 may be provided with heat dissipation fins 121, and the heat dissipation fins 121 may be used to increase the contact area of the first cooling medium with the inner wall of the battery capsule 120. For example, the battery capsule 120 may be a rectangular parallelepiped having heat dissipation fins 121 provided on at least one inner wall thereof. The heat dissipation fins 121 are disposed on the inner surface of the battery capsule 120, so that the contact area between the first cooling medium and the inner surface of the battery capsule 120 can be increased, thereby enhancing the heat transfer effect between the first cooling medium and the battery capsule 120 and accelerating the cooling of the first cooling medium.

In some embodiments, the header tank 110 includes a top surface, side surfaces, and a bottom surface, and the side surfaces of the header tank 110 are provided with at least one liquid inlet and at least one liquid outlet. Illustratively, the sides of the header tank 110 are provided with a liquid inlet 150 and a liquid outlet 160. The liquid inlet 150 is communicated with the spraying device 140, and the second cooling medium flows into the spraying device 140 through the liquid inlet 150; the second cooling medium flows out of the header tank 110 through the liquid outlet 160.

In some embodiments, the liquid inlet 150 may be in communication with a spray device 140 located above the top surface of the battery capsule 120. It should be noted that, the liquid outlet 160 is higher than the bottom surface of the battery capsule 120 and lower than the top surface of the battery capsule 120, or the liquid outlet 160 is higher than the top surface of the battery capsule 120.

By way of example, the location of the outlet 160 may include the following three arrangements. Various heat dissipation modes of the battery 130 can be realized by changing the height of the liquid outlet 160.

In the first setting, as shown in fig. 3, the position of the liquid outlet 160 may be the distance between the lowest point of the liquid outlet 160 and the bottom surface of the battery capsule 120 is smaller than a first threshold, and the first threshold may be set according to the bottom wall thickness of the liquid collecting tank 110. In this case, it can be considered that the side of the battery capsule 120 is not immersed in the second cooling medium.

It should be understood that the second cooling medium may enter the spraying device 140 from the liquid inlet 150, and the spraying device 140 may spray the second cooling medium to the battery capsule 120, where the second cooling medium flows through the top surface and the side surface of the battery capsule 120 in sequence and then directly flows out from the liquid outlet 160, so as to implement a heat dissipation mode of top surface jet flow and side surface falling film.

Wherein the first cooling medium level 122 may be as shown in fig. 3, that is, the first cooling medium level is higher than the height of the battery 130, that is, the first cooling medium completely submerges the battery 130; second cooling medium level 111 may be as shown in fig. 3, with the lower position of second cooling medium outlet 160, second cooling medium level 111 being lower and the second cooling medium not submerging the sides of battery capsule 120.

In this arrangement, when the battery 130 generates heat, the surrounding first cooling medium absorbs the heat generated by the battery 130 and is conducted to the outer surface of the battery capsule 120 through the first cooling medium; the second cooling medium is sprayed out by the spraying device 140 above the top surface of the battery capsule 120, the top surface of the battery capsule 120 is cooled by the spraying method, then the second cooling medium flows to the side surface of the battery capsule 120, the film is lowered under the action of gravity, and heat is taken away from the side surface of the battery capsule 120 by the convection heat exchange method. The heat dissipation mode of the top jet flow and the side falling film can effectively improve the heat convection coefficient of the second cooling medium and the outer surface of the battery capsule 120, so that the overall heat dissipation effect of the battery is improved.

In the second arrangement, as shown in fig. 4, the liquid outlet 160 may be located at a position where the lowest point of the liquid outlet 160 is higher than the side surface of the battery capsule 120 and lower than the top surface of the battery capsule 120. In this case, the side of the battery capsule 120 may be considered to be partially or completely immersed in the second cooling medium.

It should be understood that the second cooling medium enters the spraying device 140 from the liquid inlet 150, the spraying device 140 sprays the second cooling medium to the battery capsule 120, after the second cooling medium is injected into the liquid collecting tank 110 for a period of time, the side surface of the battery capsule 120 is immersed in the second cooling medium, and the top surface wall surface of the battery capsule 120 exchanges heat in a jet flow manner, so that a top surface jet flow and side surface immersed heat dissipation manner can be realized.

Wherein the first cooling medium level 122 may be as shown in fig. 4, that is, the first cooling medium level is higher than the height of the battery 130, that is, the first cooling medium completely submerges the battery 130; the second cooling medium level 111 may be as shown in fig. 4, and the second cooling medium may partially or completely submerge the sides of the battery capsule 120.

In this arrangement, when the battery 130 is operated to generate heat, the surrounding first cooling medium absorbs the heat generated from the battery 130 and is conducted to the outer surface of the battery capsule 120 through the first cooling medium; the second cooling medium is sprayed out by the spraying device 140 positioned on the top surface of the battery capsule 120, the top surface of the battery capsule 120 is cooled by a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule 120, and after the second cooling medium is injected for a period of time, the side surface of the battery capsule 120 is immersed in the second cooling medium, so that a top surface jet flow and side surface immersed heat dissipation mode can be realized, and heat is brought out of the liquid collecting tank 110 by the circulating flow of the second cooling medium, so that continuous heat dissipation of the battery 130 is realized. However, compared with the first heat dissipation mode, the top jet and side submerged heat dissipation mode has relatively poor heat exchange effect and relatively low heat dissipation efficiency of the battery due to the fact that the side surface of the battery capsule 120 is partially or completely immersed in the second cooling medium, and the heat exchange coefficient of the side surface is low due to the low flow velocity of the fluid on the side surface.

In a third arrangement, as shown in fig. 5, the liquid outlet 160 may be located at a position higher than the top surface of the battery capsule 120, that is, the top surface of the battery capsule 120 is located between the highest point of the liquid outlet 160 and the lowest point of the liquid outlet 160. In this case, the battery capsule 120 may be considered to be completely submerged in the second cooling medium, i.e., both the top and side surfaces of the battery capsule 120 are submerged in the second cooling medium.

When the liquid outlet 160 is higher than the top surface of the battery capsule 120, the second cooling medium enters the spraying device 140 from the liquid inlet 150, the spraying device 140 sprays the second cooling medium out of the battery capsule 120, and after the second cooling medium is injected into the header tank 110 for a period of time, the battery capsule 120 is fully immersed in the second cooling medium, so that a heat dissipation manner of immersing the top surface and the side surface can be realized.

Wherein the first cooling medium level 122 may be as shown in fig. 5, that is, the first cooling medium level is higher than the height of the battery 130, that is, the first cooling medium completely submerges the battery 130; the second cooling medium level 111 may be as shown in fig. 5, where the second cooling medium completely submerges the entire battery capsule 120, i.e., the height of the second cooling medium level 111 may be higher than the height of the battery capsule 120.

In this arrangement, when the battery 130 is operated to generate heat, the surrounding first cooling medium absorbs the heat generated from the battery 130 and is conducted to the outer surface of the battery capsule 120 through the first cooling medium; the second cooling medium is sprayed out by the spraying device 140 above the top surface of the battery capsule 120, the top surface of the battery capsule 120 is cooled by a jet flow mode, then the second cooling medium flows to the side surface of the battery capsule 120, and after the second cooling medium is injected for a period of time, the battery capsule 120 is completely immersed in the second cooling medium, so that a top surface and side surface immersed heat dissipation mode can be realized, and heat is brought out of the liquid collecting tank 110 by the circulating flow of the second cooling medium, so that continuous heat dissipation of the battery 130 is realized. It should be appreciated that the top and side submerged heat dissipation methods are relatively poor and the heat dissipation efficiency of the battery is relatively low because the top and side surfaces of the battery capsule 120 are all submerged in the second cooling medium, and the low flow rates of the top and side surfaces result in low heat exchange coefficients of the top and side surfaces.

In some embodiments, the battery capsule 120 may be contoured as shown in fig. 6-8, with fig. 6-8 showing a cross-sectional view of the energy storage device 100 along the yz plane. It should be appreciated that the top surface of battery capsule 120 may be configured in an arcuate configuration (as in fig. 6 and 7) or may be configured in a planar configuration (as in fig. 8).

In one example, the top surface of the battery capsule 120 is an arc surface, the side surface of the battery capsule 120 is perpendicular to the bottom surface of the battery capsule 120, and the shape of the battery capsule 120 may be as shown in fig. 6. The heat exchange between the battery capsule 120 and the second cooling medium may be a top jet or a side falling film.

It should be appreciated that in this example, the spraying device 140 may spray the second cooling medium along the rounded top surface of the battery capsule 120, i.e., by cooling the top surface of the battery capsule 120 by a jet, and then the second cooling medium may flow to the side of the battery capsule 120, under the force of gravity, down the side of the battery capsule 120, i.e., by cooling the side of the battery capsule 120 by a side falling film. Specifically, by setting the top surface of the battery capsule 120 to be an arc surface, a certain space can be reserved for the first cooling medium of the gas phase; the top surface of the battery capsule 120 exchanges heat with fluid under the action of jet impact by a higher convection heat exchange coefficient, so that a better heat dissipation effect is realized; the side of the battery capsule 120 exchanges heat with a higher convection heat exchange coefficient under the action of falling film cooling, so that a better heat dissipation effect is realized. In addition, the distance between the side of the battery capsule 120 and the battery is relatively small, the space occupied by the battery capsule 120 is relatively small, and the space utilization is high.

In another example, the top surface and the side surface of the battery capsule 120 are both arc surfaces, and the shape of the battery capsule 120 may be as shown in fig. 7. The height and spray range of the spray device 140 in fig. 7 are increased, and the heat exchange between the battery capsule 120 and the second cooling medium is dominant by the jet heat exchange.

It should be appreciated that in this example, the spraying device 140 may spray the second cooling medium along the rounded top and side surfaces of the battery capsule 120, i.e., by cooling the top and side surfaces of the battery capsule 120 by way of a jet. The top surface and the side surface of the circular arc shape can increase the jet flow area, and the fluid flow speed of the top surface and the side surface of the battery capsule 120 is faster, so that heat exchange is performed between the fluid and the outer surface of the battery capsule 120 with higher convection heat exchange coefficient, and a better heat dissipation effect is realized. In addition, since the top and side surfaces of the battery capsule 120 are both arc surfaces, the height of the spraying device 140 is increased, and the distance between the side surface of the battery capsule 120 and the battery is relatively large, the space occupied by the battery capsule 120 is relatively large.

In yet another example, the battery capsule 120 may have a cubic structure or a rectangular parallelepiped structure, and the battery capsule 120 may have an external shape as shown in fig. 8. The battery capsule 120 in fig. 8 has a rectangular parallelepiped structure, and the heat exchange area is greatly increased, so as to enhance the heat exchange effect of the first cooling medium and the second cooling medium.

It should be appreciated that in this example, the second cooling medium sprayed by the spraying device 140 may flow down the rectangular parallelepiped battery capsule 120, over the top and side surfaces of the battery capsule 120, so that heat transferred to the outer surface of the battery capsule 120 may be carried away. When the second cooling medium flows along the battery capsule 120 as shown in fig. 8, the heat exchange area between the second cooling medium and the battery capsule 120 is increased relative to the two modes, so that the heat exchange effect can be ensured to a certain extent.

In some embodiments, the spray device 140 is fixed to the outside of the top surface of the battery capsule 120, or the spray device 140 is fixed to the inside of the top surface of the header tank 110. The schematic structure of the shower device 140 may refer to fig. 9 and 10.

In one example, the structure of the spraying device 140 may refer to fig. 9, the spraying device 140 includes a main pipe 141, a plurality of spraying points are disposed on the main pipe 141, including a first spraying point, two sub-pipes (denoted as a first sub-pipe 142 and a second sub-pipe 143) are disposed on the first spraying point, the first sub-pipe 142 may be disposed along a first direction, the second sub-pipe 143 may be disposed along a second direction, the first direction and the second direction face the top surface of the battery capsule 120, and the first direction and the second direction form an included angle. It should be understood that the first spraying point may be one point located on the main pipe, or may be a point located on two walls of the main pipe.

In another example, the structure of the spraying device 140 may refer to fig. 10. The spraying device 140 includes a main pipe 141, a plurality of spraying points are disposed on the main pipe 141, including a first spraying point, two branch pipes (denoted as a first branch pipe 142 and a second branch pipe 143) are disposed on the first spraying point, and the first branch pipe 142 and the second branch pipe 143 may be disposed along a third direction (such as a y direction), where the third direction is parallel to a top plane of the battery capsule 120. It should be understood that the first spraying point may be one point located on the main pipe, or may be a point located on two walls of the main pipe.

It should be noted that the spraying device shown in fig. 9 or fig. 10 may be used with any of the energy storage devices shown in fig. 6 to fig. 8, which is not limited in this application. In some embodiments, the spray device 140 shown in fig. 9 may be used in conjunction with the battery capsule 120 shown in fig. 7, 8. In other embodiments, the spray device 140 shown in fig. 10 may be used in conjunction with the battery capsule 120 shown in fig. 8.

Fig. 11 is a schematic structural diagram of an energy storage system according to an embodiment of the present application.

The energy storage system 200 may comprise the energy storage device 100 as shown in fig. 1 to 8 and a heat dissipation circuit for cooling the second cooling medium.

In some embodiments, the heat dissipation circuit includes a valve 210, a water pump 220, a flow meter 230, a radiator 240, and a piping system. The valve 210 is used for controlling the flow rate of the second cooling medium in the energy storage system, the water pump 220 is used for providing the circulating power of the second cooling medium in the energy storage system, the flow rate 230 is used for measuring the flow rate of the second cooling medium in the energy storage system, the radiator 240 is used for radiating heat of the second cooling medium, and the pipeline system is used for connecting the valve 210, the water pump 220, the flowmeter 230 and the radiator 240.

It should be appreciated that the second cooling medium flows out from the liquid outlet 160 after exchanging heat with the outer surface of the battery capsule 120, the liquid outlet 160 is communicated with the circulating water pump 220 through a pipeline, a valve 210 is installed between the liquid outlet and the circulating water pump, the pipeline is used for controlling the flow rate of the second cooling medium in the energy storage system, and the flow meter 230 measures the flow rate of the second cooling medium in the energy storage system. The water pump 220 may be in communication with the radiator 240 via a pipeline for providing circulating power of the second cooling medium in the energy storage system; radiator 240 may be in communication with liquid inlet 150 via a conduit for cooling the second cooling medium. The second cooling medium can finally dissipate the heat generated by the battery 130 to the atmosphere through the radiator 240, and the second cooling medium cooled by the radiator 240 is circulated and sent to the liquid inlet 150 of the liquid collecting tank 110, thereby completing the whole circulation heat exchange scene.

In the energy storage system 200, the heat dissipation path of the battery 130 is referred to as follows: when the battery 130 generates heat, the heat may be transferred to a first cooling medium in direct contact with the battery 130, the first cooling medium may transfer the heat generated by the battery 130 to the inner surface of the battery capsule 120 by means of heat conduction, heat convection or boiling heat exchange, and the inner surface of the battery capsule 120 may transfer the heat to the outer surface of the battery capsule 120 by means of heat conduction; the outer surface of the battery capsule 120 contacts with the second cooling medium sprayed by the spraying device 140, heat is transferred to the second cooling medium in a convection heat exchange mode, and then the circulated second cooling medium is brought out of the liquid collecting tank 110; the second cooling medium is radiated by the radiator 240, so that the heat generated from the battery 130 can be radiated to the atmosphere.

In some embodiments, the energy storage system performs at least one of the following in response to the battery 130 temperature being above a first threshold: increasing the opening of the valve 210, increasing the power of the water pump 220, increasing the operating power of the radiator 240.

In this embodiment, when the temperature of the battery 130 is higher than a certain threshold, it is necessary to enhance the heat radiation capability of the energy storage system, so that the flow rate of the second cooling medium may be increased by increasing the opening degree of the valve 210, or the circulation speed of the second cooling medium may be increased by increasing the power of the water pump 220, or the heat radiation efficiency of the second cooling medium may be increased by increasing the operation power of the radiator 240.

In other embodiments, the energy storage system performs at least one of the following in response to the battery 130 temperature being below a first threshold: reducing the opening of the valve 210, reducing the power of the water pump 220, and reducing the operating power of the radiator 240.

In this embodiment, when the temperature of the battery 130 is lower than a certain threshold, it is necessary to decrease the heat dissipation capability of the energy storage system to reduce the system power consumption, the flow rate of the second cooling medium may be reduced by reducing the opening degree of the valve 210, or the circulation speed of the second cooling medium may be reduced by reducing the power of the water pump 220, or the operation power of the radiator 240 may be reduced to reduce the heat dissipation efficiency of the second cooling medium.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (14)

1. An energy storage device, characterized in that the energy storage device comprises a header tank (110), a battery capsule (120), a battery (130) and a spray device (140), wherein:

The header tank (110) is used for accommodating the battery capsule (120);

the battery capsule (120) is used for accommodating the battery (130), and the battery capsule (120) is filled with a first cooling medium which is used for cooling the battery (130);

the spraying device (140) is located above the top surface of the battery capsule (120), and the spraying device (140) is used for spraying a second cooling medium to the outer surface of the top surface of the battery capsule (120).

2. The energy storage device according to claim 1, wherein the side of the header tank (110) is provided with at least one liquid inlet (150) and at least one liquid outlet (160),

the liquid inlet (150) is communicated with the spraying device, and the second cooling medium flows into the spraying device (140) through the liquid inlet (150);

the second cooling medium flows out of the header tank (110) through the liquid outlet (160).

3. The energy storage device of claim 2, wherein the liquid outlet (160) is higher than a bottom surface of the battery capsule (120) and lower than a top surface of the battery capsule (120), or wherein the liquid outlet (160) is higher than the top surface of the battery capsule (120).

4. An energy storage device according to any one of claims 1-3, characterized in that the inner surface of the battery capsule (120) is provided with heat dissipating fins (121).

5. The energy storage device of any of claims 1 to 4, wherein the top surface of the battery capsule (120) is an arc surface, and the side surface of the battery capsule (120) is perpendicular to the bottom surface of the battery capsule (120); or alternatively, the process may be performed,

the top surface and the side surface of the battery capsule (120) are arc surfaces; or alternatively, the process may be performed,

the battery capsule (120) is of a cubic structure; or alternatively, the process may be performed,

the battery capsule (120) is of a cuboid structure.

6. The energy storage device of any of claims 1 to 5, wherein the battery (130) is partially or fully immersed in the first cooling medium.

7. The energy storage device of any of claims 1 to 6, wherein the battery capsule (120) is of a fully sealed construction.

8. The energy storage device of any one of claims 1 to 7, wherein the first cooling medium is an oil-based cooling medium and/or a fluorinated liquid-based cooling medium, and the second cooling medium comprises any one of: glycol aqueous solution, nano fluid and phase change emulsion.

9. The energy storage device according to any one of claims 1 to 8, wherein the battery (130) is a prismatic battery or a cylindrical battery or a pouch battery.

10. The energy storage device according to any one of claims 1 to 9, wherein the spraying device (140) is fixed to the outside of the top surface of the battery capsule (120) or the spraying device (140) is fixed to the inside of the top surface of the header tank (110).

11. An energy storage system, comprising:

the energy storage device of any one of claims 1 to 10;

and the heat dissipation loop is used for cooling the second cooling medium.

12. The energy storage system of claim 11, wherein the heat dissipation circuit comprises a valve (210), a water pump (220), a radiator (240) and a piping system, the valve (210) is used for controlling the flow of the second cooling medium in the energy storage system, the water pump (220) is used for providing the circulating power of the second cooling medium in the energy storage system, the radiator (240) is used for dissipating heat of the second cooling medium, and the piping system is used for connecting the valve (210), the water pump (220) and the radiator (240).

13. The energy storage system of claim 12, wherein the valve (210) opening is increased or the water pump (220) operating power is increased or the radiator (240) operating power is increased in response to the battery (130) temperature being above a temperature preset value.

14. The energy storage system of claim 12 or 13, wherein in response to the battery (130) temperature being below the temperature preset value, the valve (210) opening is reduced or the water pump (220) operating power is reduced or the radiator (240) operating power is reduced.