CN115764047A - Battery, battery pack, energy storage system and electric automobile - Google Patents

Abstract

The application relates to the technical field of batteries, in particular to a battery, a battery pack, an energy storage system and an electric automobile. The battery comprises a battery module and a thermal management module; the heat management module comprises a wrapping layer and a phase-change material filled in the wrapping layer, wherein the phase-change material is doped with a conductive medium; the wrapping layer is in contact with the battery module, and the positive electrode and the negative electrode of the battery module are respectively electrically connected with the conductive medium to form a heating loop; the battery module is used for heating the phase-change material through the heating loop so that the phase-change material is preheated for the battery module. The battery can work at a proper temperature in high-temperature and low-temperature environments, and the electrical performance of the battery is guaranteed.

Description

Battery, battery pack, energy storage system and electric automobile

Technical Field

The application relates to the technical field of batteries, in particular to a battery, a battery pack, an energy storage system and an electric automobile.

Background

The lithium ion battery has the advantages of small volume, light weight, long cycle life and the like, and is widely applied to the fields of communication base stations, data centers, energy storage power stations, electric vehicles and the like at present. In practical application, a battery cell used by a lithium ion battery has high sensitivity to temperature, so that the temperature is related to the performance of the battery cell in the aspects of life control, electrical performance, safety control and the like. In order to ensure a good cell state, the cell needs to be cooled.

In the conventional technology, the heat dissipation method for the electric core of the lithium ion battery includes natural cooling, air cooling and liquid cooling. Because the application scenes of the lithium battery are wide, the lithium ion battery has application requirements in both high-temperature environment and low-temperature environment, and the traditional heat dissipation mode cannot meet the heat management requirement of the lithium ion battery.

Disclosure of Invention

The application provides a battery, battery package, energy storage system and electric automobile, and this battery homoenergetic keeps normal operating temperature in high temperature and low temperature environment, can improve the electrical property of battery.

In a first aspect, the present application provides a battery, which can be applied in the technical fields of lithium batteries, power batteries, energy storage systems, and the like. The battery specifically includes battery module and thermal management module. The heat management module comprises a wrapping layer and a phase change material filled in the wrapping layer, and the phase change material can absorb or release heat through a phase change process. The parcel layer contacts with battery module, and battery module can carry out the heat transfer through parcel layer and phase change material. The phase-change material is doped with a conductive medium, the anode and the cathode of the battery module are respectively electrically connected with the conductive medium to form a heating loop, and the battery module can heat the phase-change material through the heating loop so that the phase-change material can be preheated for the battery module. In the battery operation process, the battery module dissipates heat, and the phase-change material in the heat management module can absorb the heat dissipated by the battery, so that the heat dissipation of the battery is realized. When the temperature of battery module was less than the normal operating temperature of battery module, switch on heating circuit, the battery module passes through heating circuit to the phase change material heating, and the phase change material temperature risees and to preheat the heat preservation to the battery module. Therefore, the battery can be kept at a proper working temperature at high temperature or low temperature, and the electrical performance of the battery is improved. Of course, the battery also has both cost and safety issues.

In order to control the heating loop conveniently, the heating loop can be provided with a temperature control unit, and the temperature control unit is used for controlling the on-off of the heating loop according to the temperature of the battery module.

In one possible implementation, the temperature control unit may be a temperature switch, and the temperature switch is connected in series with the heating circuit. The temperature switch can sense the temperature and is opened or closed according to the temperature, and then the on-off of the heating loop is controlled.

In another possible implementation manner, the temperature control unit may include a circuit switch and a control module; the circuit switch is connected in series with the heating loop, and the control module is used for controlling the circuit switch to be closed or opened. The control module can be provided with a temperature sensor for monitoring the temperature information of the battery module and controlling the action of the circuit switch through the monitored temperature information.

In some possible embodiments, the thermal management module is provided with two connection terminals electrically connected with the conductive medium; the two connecting terminals are respectively used for connecting the positive pole and the negative pole of the battery module in a one-to-one correspondence manner. One end of one wiring terminal extends into the wrapping layer to be contacted with the conductive medium, and the other end of the wiring terminal is used for being connected with the positive electrode of the battery module. One end of the other connecting terminal extends into the wrapping layer to be contacted with the conductive medium, and the other end of the connecting terminal is used for being connected with the cathode of the battery module.

The conductive medium may be, but not limited to, a carbon-based material or a metal material. When the conductive medium is a carbon-based material, the conductive medium may specifically, but not limited to, include any one or a combination of more of graphite, graphene, and a carbon-based polymer.

The battery module in the application can comprise at least two battery cells, wherein the at least two battery cells are sequentially superposed; a thermal management module may be disposed between every two adjacent cells. Along the superpose direction of electricity core, the projection of electricity core on the thermal management module falls within the surface scope that the thermal management module is used for contacting the electricity core.

In a second aspect, the present application further provides a battery pack, which includes a battery management unit and the battery provided in any one of the possible designs of the first aspect. The battery management unit is electrically connected with the battery module and used for acquiring the parameter information of the battery module and sending control information to the battery module.

In a third aspect, the present application further provides an energy storage system, which includes the battery pack proposed in the second aspect of the energy storage converter, where the energy storage converter is in signal connection with the battery management unit to process a current input to the battery pack.

In a fourth aspect, the present application further provides an electric vehicle, including a vehicle body and the energy storage system provided in the third aspect, where the vehicle body has a power module, and the energy storage system is used for supplying power to the power module.

The technical effects achieved by any one of the second to fourth aspects are described with reference to any one of the possible designs of the first aspect, and the repetition is not discussed.

Drawings

Fig. 1a is a schematic structural diagram of a lithium ion battery in the prior art;

fig. 1b is a schematic structural diagram of a liquid cooling plate of a lithium ion battery in the prior art;

fig. 2 is a schematic structural diagram of a battery provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a battery module in a battery according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of a heating circuit in a battery according to an embodiment of the present disclosure;

fig. 5 is a schematic diagram of a heating circuit in a battery according to an embodiment of the present disclosure;

fig. 6a is a schematic diagram of a heating circuit in a battery according to an embodiment of the present disclosure;

FIG. 6b is a schematic diagram of a heating circuit in a battery according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a battery provided in an embodiment of the present application;

fig. 8a is a schematic circuit diagram illustrating a connection between a battery module and a thermal management module in a battery according to an embodiment of the present disclosure;

fig. 8b is a schematic circuit diagram illustrating a connection between a battery module and a thermal management module in a battery according to an embodiment of the present disclosure;

fig. 8c is a schematic circuit diagram illustrating a connection between a battery module and a thermal management module in a battery according to an embodiment of the present disclosure;

fig. 9 is a schematic structural view of a battery module and a thermal management module in a battery according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a battery pack 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 disclosure;

fig. 12 is a schematic structural diagram of an electric vehicle according to an embodiment of the present application.

Detailed Description

The existing lithium ion battery has wide application scenes, and the application environment of the lithium ion battery may have larger temperature difference fluctuation. In order to ensure that the battery cell life control, the electrical performance and the safety control of the lithium ion battery are in a normal state, the temperature of the lithium ion battery needs to be kept within a relatively stable range. This requires heat dissipation of the lithium ion battery at high temperatures and heat preservation of the lithium ion battery at low temperatures. Generally, the lithium ion battery can be thermally managed by adopting a natural cooling mode, an air cooling mode or a liquid cooling mode. Natural cooling refers to temperature adjustment of the lithium ion battery through ambient temperature, and the mode has low heat dissipation efficiency, so that the problem that the electrical performance of the lithium ion battery is unstable in high and low temperature environments cannot be solved. The air cooling is to increase air flow to adjust the temperature of the lithium ion battery, and the mode can partially solve the problem of high-temperature heat dissipation of the lithium ion battery, but cannot solve the problem of low-temperature heat preservation of the lithium ion battery. The liquid cooling is to adjust the temperature of the lithium ion battery through the heat exchange between the liquid cooling working medium and the lithium ion battery.

Fig. 1a illustrates a conventional liquid-cooled heat dissipation lithium ion battery. In the lithium ion battery, a liquid cooling plate 2 'is inserted between two adjacent electric cores 1', and as shown in fig. 1b, a liquid cooling pipeline 21 'is arranged in the liquid cooling plate 2', and the liquid cooling pipeline is connected with an external cold source. And a cooling working medium is circularly supplied to the liquid cooling pipeline 21 'through an external cold source, and the cooling working medium is subjected to cold and heat exchange with the battery cell 1' through the liquid cooling pipeline 21 'so as to adjust the temperature of the battery cell 1'. Although the method can solve the problem of high and low temperature, the hidden danger that the cooling working medium influences the safety problem of the lithium ion battery exists, and the cost is high. Therefore, the traditional lithium ion battery thermal management mode is difficult to meet the thermal management requirement of the lithium ion battery in a complex environment.

Based on this, this application embodiment provides a battery, energy storage system and electric automobile, and the battery that this application provided can all keep suitable operating temperature under high temperature or low temperature, guarantees the electrical property performance of battery. The battery can be applied to application scenes such as lithium batteries, power batteries and energy storage systems. Because the pool also considers the problems of cost and safety, the pool is beneficial to popularization and application.

The terminology used in the following examples is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise.

Reference throughout this 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 present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless otherwise specifically stated.

As shown in fig. 2, the battery 10 provided in the embodiment of the present application may be a lithium ion battery, a sodium ion battery, a lithium metal battery, a power battery, or the like. In the following examples, a lithium ion battery is specifically exemplified. The battery 10 includes a case 1, a battery module 2, and a thermal management module 3. The shell 1 is boxed, and inside is formed with holds the cavity, and battery module 2 and thermal management module 3 can set up in the cavity that holds of shell 1. The battery module 2 is a core component of the battery 10, and stores electric energy and exerts electrical properties. The battery module 2 needs to operate within a suitable temperature range to ensure the exertion of electrical properties. The thermal management module 3 includes a wrapping layer 31 and a phase change material 32 filled in the wrapping layer 31, wherein the phase change material 32 is doped with a conductive medium 33. Wherein, the wrapping layer 31 may be made of an insulating material. The phase change material 32 refers to a substance that changes form with a change in temperature and can provide latent heat. The process of the phase change material 32 changing from a solid state to a liquid state or from a liquid state to a solid state is referred to as a phase change process. The phase change material 32 absorbs heat when heated from a solid to a liquid and releases heat when cooled from a liquid to a solid.

The wrapping layer 31 of the thermal management module 3 is in contact with the battery module 2, and when the temperature of the battery module 2 is higher, heat exchange can be carried out between the wrapping layer and the battery module 2 through the phase-change material 32, so that heat dissipation of the battery module 2 is realized.

The positive electrode and the negative electrode of the battery module 2 are respectively electrically connected with the conductive medium 33 in the thermal management module 3, so that a heating loop is formed between the battery module 2 and the thermal management module 3. When the temperature of the battery module 2 is low, the heating circuit is turned on, and the battery module 2 can heat the phase change material 32 through the conductive medium 33. The phase change material 32 is increased in temperature to store heat, and can preheat the battery module 2. In this operating mode, the battery module 2 can be kept warm by the heat storage capacity of the phase change material 32 while the battery module 2 is self-heating, and the cooling rate of the battery module 2 is reduced.

The working principle of the battery 10 provided by the embodiment of the application is as follows: in the operation process of the battery 10, the battery module 2 dissipates heat, and the phase change material 32 in the thermal management module 3 can absorb the heat dissipated by the battery 10, so that the heat dissipation of the battery 10 is realized. When the temperature of battery module 2 was less than the normal operating temperature of battery module 2, switched on heating circuit, battery module 2 passed through conducting medium 33 and heats phase change material 32, and phase change material 32 temperature rise preheats heat preservation to battery module 2. Meanwhile, the heat storage of the phase change material 32 can reduce the cooling rate of the battery module 2. After a period of time, the phase change material 32 is heated to gradually melt and release heat, and the released heat can further reduce the cooling rate of the battery module 2. When the temperature of the battery module 2 is higher than the predetermined temperature, the heating circuit is turned off, and the temperature of the phase change material 32 is gradually decreased. It should be understood that the phase change process of the phase change material 32 is a gradual process, so that a relatively gentle temperature change can be maintained, the temperature fluctuation of the battery module 2 is reduced, and the temperature uniformity of the battery module 2 can be improved.

The phase change material 32 is generally classified into inorganic type (crystalline hydrate salt, molten salt, etc.), organic type (paraffin type, ester acid type, etc.) and composite type according to chemical components. The conductive medium may be a carbon-based material, such as any one or combination of graphite, graphene, and carbon-based polymers.

As shown in fig. 2 and 3, the battery module 2 has a positive electrode A1 and a negative electrode A2, and the battery module 2 can be connected to the heating circuit through the positive electrode A1 and the negative electrode A2. The thermal management module 3 is provided with two wiring terminals B, one end of each wiring terminal B extends into the phase change material 32 to contact with the conductive medium 33, and the other end of each wiring terminal B extends out of the wrapping layer 31 and is connected with the positive electrode A1 and the negative electrode A2 of the battery module 2 in a one-to-one correspondence manner, so that the heating loop can be formed between the battery module 2 and the thermal management module 3. The connecting terminal B can be connected with the anode A1 and the cathode A2 through leads.

As shown in fig. 4, when the heating circuit is turned on, the battery module 2 may discharge electricity to the conductive medium 33 through the two terminals B to increase the temperature of the phase change material 32, so that the phase change material 32 preheats the battery module 2 and increases the temperature of the battery module 2.

When the battery 10 is operated, the thermal management module 3 may absorb heat of the battery module 2 through the phase change material 32, thereby achieving heat dissipation of the battery module 2. When the temperature of the battery module 2 is lower than the normal working temperature, the heating circuit is turned on, the battery module 2 heats the phase-change material 32 through the heating circuit, and the battery module 2 is preheated through the phase-change material 32. The normal operating temperature of the battery module 2, that is, the temperature at which the battery 10 operates normally, is a temperature range within which the temperature change does not have a great influence on the performance of the electrical characteristics of the battery 10.

As shown in fig. 5, in order to control the heating circuit, a temperature control unit 4 may be further disposed in the heating circuit, and the temperature control unit 4 may control the on/off of the heating circuit according to the temperature of the battery module 2. The temperature control unit 4 may be provided between the positive electrode A1 of the battery module 2 and the corresponding connection terminal B, or between the negative electrode A2 of the battery module 2 and the corresponding connection terminal B.

In some embodiments, as shown in fig. 6a, the temperature control unit 4 may be a temperature switch connected in series in the heating circuit, for example, the temperature switch may be disposed between the positive electrode A1 of the battery module 2 and the connection terminal B of the thermal management module 3. The temperature switch can sense the temperature and is opened or closed according to the temperature, and then the on-off of the heating loop is controlled. Specifically, when the temperature of the battery module 2 is within the normal operating temperature range, the temperature switch is in a normally open state, and the heating circuit is disconnected. When the temperature of the battery module 2 is lower than the normal working temperature range, the temperature switch is closed, and the heating loop is conducted.

In other embodiments, as shown in fig. 6b, the temperature control unit 4 may further include a circuit switch 41 and a control module 42, and the control module 42 may open or close the circuit switch 41. The control module 42 may be a control circuit having a temperature sensor for monitoring temperature information of the battery module 2, and may control the operation of the circuit switch 41 according to the monitored temperature information. Specifically, when the temperature of the battery module 2 is within the normal operating temperature range, the control module 42 controls the circuit switch 41 to be turned on, and the heating circuit is turned off. When the temperature of the battery module 2 is lower than the normal working temperature range, the control module 42 controls the circuit switch 41 to be closed, and the heating loop is conducted.

As shown in fig. 7, the battery module 2 may include at least two battery cells 21, and fig. 7 illustrates that 4 battery cells 21 are schematically illustrated as an example. The battery cell 21 has a rectangular parallelepiped shape and a relatively thin thickness, and can be considered as a continuous plate structure. The at least two battery cells 21 are sequentially stacked along a set direction, and the plurality of battery cells 21 are connected in series or in parallel. The setting manner here may be considered as the thickness direction of the battery cells 21, and the following embodiments will exemplarily describe the connection in series among the plurality of battery cells 21. Here, it is illustrated that 4 battery cells 21 are connected to each other by a cell connecting sheet 22 to realize series connection. Use two adjacent electric cores 21 as a set of, set up a thermal management module 3 between two adjacent electric cores 21. The thermal management module 3 may have a rectangular parallelepiped shape and a relatively thin thickness, and may be considered as a continuous plate structure. In the structure shown in fig. 7, along the thickness direction of the battery cells 21, each battery cell 21 has a surface perpendicular to the thickness direction to contact the thermal management module 3, so that each battery cell 21 can exchange heat with the thermal management module 3. The area of each cell 21 in contact with the thermal management module 3 is substantially uniform, which allows the temperature of each cell 21 to be influenced by the thermal management module 3 substantially uniformly. Wherein, the face that electric core 21 is used for contacting thermal management module 3 is the biggest surface of electric core 21, and the heat transmission efficiency between phase change material 32 in the thermal management module 3 and electric core 21 is than higher, can improve heat dissipation or heating efficiency.

In the present embodiment, "at least two" means two or more, and may be considered plural.

The battery module 2 has a positive electrode A1 and a negative electrode A2, and the plurality of thermal management modules 3 may be sequentially connected in series to connect the positive electrode A1 and the negative electrode A2 of the battery module 2 to form a heating circuit. Or a plurality of thermal management modules 3 may be arranged in parallel, that is, each thermal management module 3 is connected to the positive electrode A1 and the negative electrode A2 of the battery module 2 to form a heating loop.

Specifically, as shown in fig. 8a, the structure in which the thermal management modules 3 are connected in series may be that after the thermal management modules 3 are connected in series, two connection terminals B are electrically connected with the positive electrode A1 and the negative electrode A2 of the battery module 2 to form a heating circuit, and a temperature control unit 4 is disposed between the positive electrode A1 and the corresponding connection terminal B.

The structure in which the thermal management modules 3 are connected in parallel may be as shown in fig. 8B and 8c, each thermal management module 3 has two connection terminals B, and each thermal management module 3 is electrically connected to the positive electrode A1 and the negative electrode A2 of the battery module 2 through the two connection terminals B to form a heating circuit. It can be considered that one heating circuit is formed between each thermal management module 3 and the battery module 2, and the entire battery 10 has a plurality of heating circuits. In fig. 8B, a temperature control unit 4 is disposed between the positive electrode A1 and the corresponding plurality of terminals B, and the temperature control unit 4 can simultaneously control the on/off of the plurality of heating circuits. In fig. 8c, a temperature control unit 4 is disposed between the terminal B of each thermal management module 3 for connecting the positive electrode A1 and the positive electrode A1, and each temperature control unit 4 can correspondingly control the on/off of one heating circuit. It will be appreciated that when the plurality of temperature control units 4 in fig. 8c are operated in synchronism, synchronous control of the plurality of heating circuits can be achieved.

When the battery 10 works and generates heat, the phase-change material 32 in the thermal management module 3 is heated to generate phase change, so that the temperature of the battery cell 21 can be absorbed, and the heat dissipation of the battery cell 21 is realized. When the temperature of the battery cell 21 is lower than the normal working temperature range, the heating loop is switched on, so that the phase change material 32 in the thermal management module 3 is heated by the battery module 2, and the battery cell 21 can be preheated by the temperature rise of the phase change material 32. The temperature of the battery module 2 is kept within the normal working temperature range, and the battery core 21 can normally work at a proper temperature to exert good electrical performance.

As shown in fig. 9, taking the example that the battery module 2 includes two battery cells 21, the two battery cells 21 are stacked in sequence, and one thermal management module 3 is disposed between the two battery cells 21. Along the superpose direction of battery cell 21, the projection of thermal management module 3 on shell 1 covers the projection of battery cell 21 on shell 1. It is also considered that the projection of the cell 21 on the thermal management module 3 completely falls within the range of the surface of the thermal management module 3 for contacting the cell 21. In the structure illustrated in fig. 9, the edge of the thermal management module 3 protrudes out of the edge of the battery cell 21 on the plane perpendicular to the stacking direction of the battery cells 21. With such a structure, the thermal management module 3 can sufficiently dissipate or heat the battery cell 21.

Based on the battery 10, as shown in fig. 10, the present embodiment provides a battery pack 100, where the battery pack 100 includes a battery management unit 20 and the battery 10 described in the above embodiment, and the battery management unit is electrically connected to the battery module 2 in the battery 10, and is configured to acquire parameter information of the battery 10 and send control information to the battery 10. Since the battery pack 100 includes the battery 10, the battery pack 100 also has all or at least some of the advantages of the battery 10, and thus, the detailed description thereof will not be repeated.

The embodiment of the present application further provides an energy storage system 300, as shown in fig. 11, the energy storage system 300 includes an energy storage converter 200 and the battery pack 100, wherein the energy storage converter 200 is electrically connected to the battery management unit 20 of the battery pack 100, and is configured to process the current input into the battery pack 100 and input the current into the battery pack 100. Since the battery pack 100 includes the battery 10, the energy storage system 300 also has all or at least some of the advantages of the battery 10, and the detailed description is not repeated here.

The embodiment of the present application further provides an electric vehicle, as shown in fig. 12, the electric vehicle includes a vehicle body 400 and the energy storage system 300. The vehicle body 400 is provided with a power module 401, and the power module 401 is a power system of the electric vehicle. The energy storage system 300 is used for supplying power to the power module 401, and the power module 401 can convert electric energy into mechanical energy to drive the electric vehicle.

The above description is only for the 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 conceive of the changes or substitutions within the technical scope of the present application, and shall 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 (11)

1. The battery is characterized by comprising a battery module and a thermal management module;

the heat management module comprises a wrapping layer and a phase-change material filled in the wrapping layer, wherein the phase-change material is doped with a conductive medium; the wrapping layer is in contact with the battery module, and the anode and the cathode of the battery module are respectively and electrically connected with the conductive medium to form a heating loop; the battery module is used for heating the phase-change material through the heating loop so as to preheat the battery module by the phase-change material.

2. The battery of claim 1, wherein the heating loop is provided with a temperature control unit, and the temperature control unit is used for controlling the on-off of the heating loop according to the temperature of the battery module.

3. The battery of claim 2, wherein the temperature control unit is a temperature switch connected in series with the heating circuit.

4. The battery of claim 2, wherein the temperature control unit comprises a circuit switch and a control module; the circuit switch is connected in series with the heating loop, and the control module is used for controlling the circuit switch to be closed or opened.

5. The battery according to any one of claims 1-4, wherein the thermal management module is provided with two terminals electrically connected to the conductive medium; the two wiring terminals are respectively used for connecting the positive electrode and the negative electrode of the battery module in a one-to-one correspondence manner.

6. The cell defined in any one of claims 1-5, wherein the conductive medium comprises any one or combination of graphite, graphene, and a carbon-based polymer.

7. The battery of any one of claims 1-6, wherein the battery module comprises at least two cells, and the at least two cells are stacked in sequence; and one thermal management module is arranged between every two adjacent electric cores.

8. The battery of claim 7, wherein a projection of the cell onto the thermal management module, in a stacking direction of the cell, falls within a range of a surface of the thermal management module for contacting the cell.

9. A battery pack comprising a battery management unit and a battery according to any one of claims 1-8;

the battery management unit is electrically connected with the battery module and used for acquiring the parameter information of the battery module and sending control information to the battery module.

10. An energy storage system comprising an energy storage converter and a battery pack as claimed in claim 9, the energy storage converter being in signal connection with the battery management unit for processing the current input to the battery pack.

11. An electric vehicle comprising a vehicle body having a power module and an energy storage system according to claim 10 for powering the power module.

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