Auxiliary temperature control device and household energy storage device

Abstract

The application discloses an auxiliary temperature control device and a household energy storage device, and relates to the technical field of energy storage devices; the auxiliary temperature control device comprises an elastic film bag, a conveying pump and a liquid accumulator; the elastic film bag is arranged between a battery module and the inner wall of a shell in a battery pack; the liquid accumulator is used for storing liquid working medium with high heat conductivity; the conveying pump is connected between the elastic film bag and the liquid accumulator through a pipeline and is used for bidirectional pumping of the liquid working medium between the elastic film bag and the liquid accumulator. The household energy storage device comprises the auxiliary temperature control device. The application has the beneficial effects that: through filling and extraction of the high-heat-conductivity liquid working medium in the elastic film bag, flexible switching of a heat dissipation mode and a heat preservation mode is realized. In the heat dissipation mode, the high-heat-conductivity liquid working medium is filled between the battery module and the inner wall of the shell, a low-thermal-resistance heat conduction path is established, and the temperature rise of the battery cell is effectively inhibited; in the heat preservation mode, the liquid working medium is extracted back, the elastic film bag is curled and air convection is hindered, and heat loss is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage equipment technology, and in particular to an auxiliary temperature control device and a residential energy storage device. Background Technology

[0002] In the application of residential energy storage products, cell temperature directly affects product performance and lifespan. For example, a 314Ah battery with a rated discharge capacity of 0.5P (157A) cannot be charged when the cell temperature is below 0℃, cannot be discharged when the cell temperature is below -20℃, and requires a reduction in charge / discharge rate when the cell temperature is above 45℃. Furthermore, the cycle life of the cell will also decrease when operating at low or high temperatures. Therefore, it is necessary to keep the cell operating within a suitable operating temperature range as much as possible. Taking lithium-ion batteries as an example, the recommended suitable temperature range is 25~35℃.

[0003] Temperature control for residential energy storage products includes heat dissipation and insulation. For heat dissipation, existing residential energy storage products generally rely on natural cooling. During cell charging and discharging, the temperature rises, and heat is dissipated through conduction and natural convection, resulting in limited efficiency. For insulation, existing residential energy storage products typically incorporate a certain thickness of insulation material at the bottom of the cells or around the battery pack. However, for products using passive cooling, strengthening insulation weakens heat dissipation, and vice versa. This makes it difficult for existing residential energy storage products to achieve self-consistent control of heat dissipation and insulation, leading to potential thermal runaway safety issues when cell temperatures are too high, and severely impacting lifespan and performance when cell temperatures are too low. Utility Model Content

[0004] One objective of this application is to provide an auxiliary temperature control device that can solve at least one of the defects in the aforementioned background technology.

[0005] Another objective of this application is to provide a residential energy storage device that can solve at least one of the defects in the aforementioned background technology.

[0006] To achieve at least one of the above objectives, one aspect of this application provides an auxiliary temperature control device for a battery pack, the battery pack including a housing and a battery module disposed within the housing; the auxiliary temperature control device includes an elastic membrane bag, a delivery pump, and a reservoir; the elastic membrane bag is disposed between the battery module and the inner wall of the housing within the battery pack; the reservoir is used to store a liquid working fluid with high thermal conductivity; the delivery pump is connected between the elastic membrane bag and the reservoir via a pipeline, and is used to bidirectionally pump the liquid working fluid between the elastic membrane bag and the reservoir; the elastic membrane bag is adapted to expand to contact the inner wall of the battery module and the housing when filled with the liquid working fluid, so that the battery module can accelerate heat dissipation to the housing through the liquid working fluid; the elastic membrane bag is adapted to impede air convection between the inner wall of the battery module and the housing after the liquid working fluid is extracted.

[0007] Preferably, the elastic membrane bag is installed on the side of the battery module, such that the elastic membrane bag wrinkles and adheres to the side of the battery module after the liquid working medium is extracted; the elastic membrane bag expands towards the inner wall of the housing until it contacts the liquid working medium when it is filled.

[0008] Preferably, the elastic membrane bag is installed on the inner wall of the housing, such that the elastic membrane bag wrinkles and adheres to the inner wall of the housing after the liquid working medium is extracted; the elastic membrane bag expands towards the side of the battery module until it contacts the liquid working medium when it is filled.

[0009] Preferably, the elastic membrane bag is installed in the gap between the battery module and the inner wall of the housing, and the elastic membrane bag curls up after the liquid working fluid is extracted.

[0010] Preferably, the elastic membrane bag is provided with multiple interconnected air chambers, and after the liquid working fluid is extracted, the elastic membrane bag forms an irregular curl through the air chambers.

[0011] Preferably, the elastic film bag has a plurality of air chambers evenly arranged along its width; and / or, the elastic film bag has a plurality of air chambers evenly arranged along its height.

[0012] Preferably, the elastic membrane bag is processed to obtain the air chamber through hot pressing, high-frequency welding or bonding processes.

[0013] Preferably, the liquid reservoir is disposed on the top of the battery module. The liquid reservoir includes a rigid outer shell and a soft container bag disposed inside the rigid outer shell. The liquid working fluid is stored in the soft container bag. The rigid outer shell is fixedly connected to the inner wall of the housing.

[0014] Preferably, the auxiliary temperature control device further includes an electronic control board, which is electrically connected to the delivery pump; the electronic control board is adapted to receive control signals based on the temperature changes of the battery module, and to control the start, stop and directional control of the delivery pump according to the received control signals.

[0015] Another aspect of this application provides a residential energy storage device, including a housing, a plurality of battery cells, and the aforementioned auxiliary temperature control device; the plurality of battery cells form at least one battery module, the battery module being installed inside the housing to form a battery pack; the auxiliary temperature control device is installed between at least one side of the battery module and the inner wall of the housing.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: This application achieves flexible switching between heat dissipation and heat preservation modes by filling and extracting a highly thermally conductive liquid working medium inside an elastic membrane bag. In heat dissipation mode, the highly thermally conductive liquid working medium fills the space between the battery module and the inner wall of the casing, establishing a low thermal resistance heat conduction path and effectively suppressing the rise in cell temperature. In heat preservation mode, the liquid working medium is extracted, and the elastic membrane bag curls up to impede air convection, reducing heat loss. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of the battery pack in this application; Figure 2 This is a schematic diagram of the auxiliary temperature control device in this application; Figure 3 This is a partial structural diagram of the elastic membrane bag in this application.

[0018] In the diagram: battery pack 01, casing 100, elastic membrane bag 21, air chamber 210, connection port 211, delivery pump 22, liquid reservoir 23, electronic control board 24, battery module 300, and battery cell 310. Detailed Implementation

[0019] The present application will now be further described in conjunction with specific embodiments. It should be noted that, in the description of this specification, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0020] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0021] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0024] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0025] One aspect of this application provides an auxiliary temperature control device for battery pack 01; such as Figure 1 and Figure 2As shown, one preferred embodiment includes an elastic membrane bag 21, a delivery pump 22, and a reservoir 23. The battery pack 01 includes a housing 100 and a battery module 300 disposed within the housing 100. The elastic membrane bag 21 is disposed between the battery module 300 and the inner wall of the housing 100 within the battery pack 01. The reservoir 23 stores a liquid working fluid with high thermal conductivity. The delivery pump 22 is connected to the elastic membrane bag 21 and the reservoir 23 via a pipeline, and is used to bidirectionally pump the liquid working fluid between the elastic membrane bag 21 and the reservoir 23. The elastic membrane bag 21 can expand to contact the inner wall of the battery module 300 and the housing 100 when filled with the liquid working fluid, allowing the battery module 300 to accelerate heat dissipation to the housing 100 through the liquid working fluid. After the liquid working fluid is extracted, the elastic membrane bag 21 can impede air convection between the battery module 300 and the inner wall of the housing 100.

[0026] It should be understood that liquid working fluid refers to liquid materials with high thermal conductivity, such as liquid metals (e.g., gallium-based alloys, indium-based alloys), heat-conducting oils, or other highly thermally conductive liquids. Their thermal conductivity is much higher than that of air, effectively reducing the thermal resistance of the heat conduction path. When the elastic membrane bag 21 is filled with liquid working fluid, it expands and contacts both the inner wall of the housing 100 and the battery module 300. The heat generated by the battery module 300 during operation can then be quickly absorbed by the liquid working fluid through the elastic membrane bag 21, and the liquid working fluid then transfers the heat to the inner wall of the housing 100 for heat dissipation.

[0027] Understandably, this application achieves switching between heat dissipation and heat preservation modes by filling and extracting the liquid working medium within the elastic membrane bag 21, effectively accommodating the temperature control requirements of the energy storage device under different ambient temperatures. When the battery module 300 temperature is high, the heat dissipation mode is executed; in this mode, the highly thermally conductive liquid working medium fills the elastic membrane bag 21, establishing a low thermal resistance heat conduction path between the battery module 300 and the inner wall of the housing 100. When the battery module 300 temperature is low, the heat preservation mode is executed; in this mode, the liquid working medium is drawn back into the reservoir 23, and the elastic membrane bag 21 impedes air convection, reducing heat loss.

[0028] It is important to know that there are multiple ways to install the elastic film bag 21, and its form in the heat preservation mode will be different depending on the installation method. To facilitate understanding, three specific examples will be used to describe this in detail below.

[0029] Example 1: The elastic membrane bag 21 is installed on the side of the battery module 300, so that the elastic membrane bag 21 is wrinkled and attached to the side of the battery module 300 after the liquid working medium is extracted; when the elastic membrane bag 21 is filled with liquid working medium, it expands towards the inner wall of the housing 100 until it contacts the liquid working medium.

[0030] Understandably, in this example, the side surface of the battery module 300 is typically a large planar area within the battery module 300, such as the side formed by multiple battery cells 310 arranged together. The elastic membrane bag 21 can be fixed to the side of the battery module 300 by means of adhesive bonding, binding, or snap-fit ​​connection. When the liquid working fluid is extracted, the elastic membrane bag 21 collapses due to the loss of internal support. Under its own gravity and / or elastic restoring force, it adheres to the side surface of the battery module 300, forming a heat insulation layer covering the side of the battery module 300, which helps reduce the heat dissipation of the battery module 300 to the outside through the side. When the liquid working fluid is pumped into the elastic membrane bag 21, the elastic membrane bag 21 expands towards the inner wall of the housing 100. Its side surface away from the battery module 300 gradually approaches and eventually contacts the inner surface of the inner wall of the housing 100, thereby establishing a low thermal resistance heat dissipation path with the liquid working fluid as the heat conduction medium between the battery module 300 and the inner wall of the housing 100.

[0031] Example 2: The elastic membrane bag 21 is installed on the inner wall of the housing 100, so that the elastic membrane bag 21 is wrinkled and attached to the inner wall of the housing 100 after the liquid working medium is extracted; the elastic membrane bag 21 expands to the side of the battery module 300 until it contacts when the liquid working medium is filled.

[0032] Understandably, in this example, the elastic membrane bag 21 can be fixed to the inner surface of the inner wall of the housing 100 by means of adhesion, magnetic attraction, or snap-fit ​​connection. When the liquid working fluid is extracted, the elastic membrane bag 21 adheres to the inner surface of the inner wall of the housing 100, forming a heat insulation layer on the inner side of the inner wall of the housing 100, reducing the conduction of cold energy from the external low-temperature environment to the battery module 300 through the inner wall of the housing 100. When the liquid working fluid is pumped into the elastic membrane bag 21, the elastic membrane bag 21 expands towards the side of the battery module 300, and its side surface away from the inner wall of the housing 100 gradually approaches and eventually contacts the side surface of the battery module 300, similarly establishing a low thermal resistance heat dissipation path with the liquid working fluid as the heat conduction medium between the battery module 300 and the inner wall of the housing 100.

[0033] Example 3: The elastic membrane bag 21 is installed in the gap between the battery module 300 and the inner wall of the housing 100. The elastic membrane bag 21 curls up after the liquid working fluid is extracted.

[0034] Understandably, in this example, the elastic membrane bag 21 is positioned in the space between the side surface of the battery module 300 and the inner surface of the inner wall of the housing 100. It is neither fixed to the side of the battery module 300 nor to the inner wall of the housing 100, but rather serves as an independent filling element within this gap. The width of this gap is typically a few millimeters to a few centimeters, determined by the difference between the dimensions of the battery module 300 and the internal dimensions of the housing 100. When the liquid working fluid is extracted, the elastic membrane bag 21, losing the support of the internal liquid working fluid, undergoes irregular folding, bending, and contraction, forming a fluffy, irregularly shaped, rolled-up mass. This rolled-up state divides the originally flat air gap into numerous irregular small spaces, effectively hindering the convection flow of air within the gap.

[0035] It should be understood that the above three examples can all meet the actual needs of this application, and those skilled in the art can choose according to their actual needs. In this embodiment, example three is preferred.

[0036] In this embodiment, as Figure 2 As shown, the elastic membrane bag 21 is provided with multiple interconnected air chambers 210. After the liquid working fluid is extracted, the elastic membrane bag 21 forms an irregular curl through the air chambers 210.

[0037] It is important to understand that each air chamber 210 refers to a plurality of interconnected small spaces within the elastic membrane bag 21; a single air chamber 210 can be circular, rectangular, or other regular polygonal. Each air chamber 210 has a certain volume, and the air chambers 210 are interconnected, allowing the liquid working medium to flow between them. To achieve rapid flow of the liquid working medium between the air chambers 210, such as... Figure 3 As shown, each air chamber 210 can be connected to all adjacent air chambers 210 through a connection port 211.

[0038] It should be understood that when the liquid working fluid is extracted, since each air chamber 210 is independent of the others through connection points or connecting strips, each air chamber 210 contracts, folds, and bends in different directions after losing its internal support, causing the entire elastic membrane bag 21 to exhibit an irregular curled shape. This irregular curled shape can effectively disrupt the airflow path between the battery module 300 and the inner wall of the housing 100, significantly reducing the air convection heat transfer coefficient. In this embodiment, by setting multiple air chambers 210, the elastic membrane bag 21 can form a richer and more uncertain curled shape after liquid extraction, thereby more effectively suppressing air convection and improving the heat preservation effect. At the same time, in the liquid-filled state, the presence of multiple air chambers 210 allows the elastic membrane bag 21 to expand more uniformly, avoiding local over-expansion or under-expansion, and ensuring good contact with the inner wall of the battery module 300 and the housing 100.

[0039] In this embodiment, as Figure 2 and Figure 3 As shown, the elastic film bag 21 can be uniformly provided with multiple air chambers 210 along the width direction; or, the elastic film bag 21 can be uniformly provided with multiple air chambers 210 along the height direction; or, the multiple air chambers 210 can be uniformly provided along both the width and height directions of the elastic film bag 21.

[0040] It should be understood that, generally speaking, the width direction of the elastic membrane bag 21 refers to its transverse direction, and the height direction refers to its vertical direction. In this embodiment, by uniformly distributing multiple air chambers 210, the elastic membrane bag 21 expands more evenly during liquid filling and curls more fully and regularly during liquid extraction (i.e., the degree of curling in each air chamber is similar), thereby achieving a more predictable heat dissipation and insulation effect. The uniformly distributed air chambers 210 also avoid localized stress concentration, extending the service life of the elastic membrane bag 21.

[0041] It is understandable that there are various ways to process the elastic membrane bag 21 to obtain the air chamber 210, such as using one of the following processes: hot pressing, high-frequency welding or bonding.

[0042] Specifically, the hot-pressing process refers to applying pressure to the upper and lower walls of the elastic film bag 21 using a heated mold, causing the upper and lower walls to melt and bond together at a predetermined position, thereby forming connection points or connecting strips and dividing the interior of the film bag into multiple air chambers 210. The hot-pressing process is suitable for thermoplastic elastomer materials, such as thermoplastic polyurethane (TPU) and polyvinyl chloride (PVC).

[0043] High-frequency welding refers to the process of using a high-frequency electric field to cause the polar molecules inside the elastic membrane bag 21 to oscillate at high frequency and generate heat, causing the upper and lower walls to melt and bond together at a predetermined position. High-frequency welding has advantages such as fast heating speed, high welding strength, and minimal thermal impact on the overall membrane material, making it particularly suitable for processing flexible polymer film materials.

[0044] The bonding process refers to bonding the upper and lower walls of the elastic membrane bag 21 together at predetermined positions using an adhesive to form connection points or connecting strips. The bonding process is suitable for membrane materials that are heat-sensitive or unsuitable for heating.

[0045] It should be understood that the above three processes can be used individually or in combination. For example, the main air chamber partition structure can be formed first by hot pressing or high-frequency welding, and then local reinforcement can be carried out by bonding.

[0046] In a specific embodiment, such as Figure 1As shown, the liquid reservoir 23 is disposed on the top of the battery module 300; the liquid reservoir 23 includes a rigid outer shell and a soft container bag disposed inside the rigid outer shell, the liquid working fluid is stored in the soft container bag, and the rigid outer shell is fixedly connected to the inner wall of the housing 100.

[0047] It should be understood that by placing the liquid reservoir 23 on top of the battery module 300, gravity can be used to assist the flow of the liquid working fluid from the reservoir 23 to the elastic membrane bag 21, while also facilitating pipeline layout. The rigid outer shell of the liquid reservoir 23 provides structural support and fixation, and can be made of metal or rigid plastic, and is fixed to the inner wall of the housing 100 or the end plate of the battery module 300 by bolts, clips, or welding. The flexible container bag is located inside the rigid outer shell and is used to directly store the liquid working fluid. It can be made of the same flexible material as the elastic membrane bag 21. Since the flexible container bag can contract or expand with changes in the volume of the internal working fluid, its internal space does not need to be connected to the atmosphere, thus eliminating the need for additional pressure balancing components such as vent valves.

[0048] In one specific embodiment, the auxiliary temperature control device further includes an electronic control board 24, which is electrically connected to the delivery pump 22. The electronic control board 24 is adapted to receive control signals based on the temperature changes of the battery module 300, and to control the start, stop and direction of the delivery pump 22 according to the received control signals.

[0049] It should be understood that the electronic control board 24 refers to a circuit board with signal receiving, processing and output functions, which may include components such as microcontroller (MCU), drive circuit, and communication interface; the electronic control board 24 is electrically connected to the delivery pump 22 and is used to supply power to the delivery pump 22 and issue control commands.

[0050] The control signal based on the temperature change of the battery module 300 refers to the electrical signal characterizing the temperature state of the battery module 300, which can be provided by the battery management system (BMS). The battery management system monitors the temperature of each cell 310 in the battery module 300 in real time. When the temperature of a cell 310 exceeds a first preset threshold (e.g., 35°C), the battery management system sends a first control signal to the electronic control board 24; when the temperature of a cell 310 is lower than a second preset threshold (e.g., 25°C), the battery management system sends a second control signal to the electronic control board 24. When the electronic control board 24 receives the first control signal, it controls the delivery pump 22 to operate in the forward direction, pumping the liquid working fluid from the reservoir 23 into the elastic membrane bag 21, causing the elastic membrane bag 21 to expand and contact the inner wall of the battery module 300 and the housing 100, thus activating the heat dissipation mode. When the electronic control board 24 receives the second control signal, the electronic control board 24 controls the delivery pump 22 to run in reverse, drawing the liquid working medium from the elastic membrane bag 21 back into the liquid reservoir 23, causing the elastic membrane bag 21 to shrink and curl, and starting the heat preservation mode.

[0051] To further ensure the operational stability of the elastic membrane bag 21, pressure sensors can be installed at the inlet and outlet of the delivery pump 22, and the pressure sensors are connected to the electronic control board 24. When the pressure sensor detects that the pressure value on one side of the delivery pump 22 exceeds the preset pressure threshold, it indicates that the side is filled or emptied of liquid working medium. Based on this, the electronic control board 24 controls the delivery pump 22 to stop operating, avoiding overcharging or over-draining that could damage the membrane bag or cause the pump to run dry.

[0052] Another aspect of this application provides a residential energy storage device, such as Figure 1 As shown, one preferred embodiment includes a housing 100, a plurality of battery cells 310, and the aforementioned auxiliary temperature control device; the plurality of battery cells 310 form at least one battery module 300, and the battery module 300 is installed inside the housing 100 to form a battery pack 01; an auxiliary temperature control device is installed between at least one side of the battery module 300 and the inner wall of the housing 100.

[0053] It should be understood that battery module 300 refers to a battery unit composed of multiple battery cells 310, which can be connected in series and / or in parallel to form battery module 300; a single battery pack 01 includes at least one battery module 300, and an auxiliary temperature control device is installed between each battery module 300 and the inner wall of the housing 100. When installing the auxiliary temperature control device, the elastic film bag 21 can be set on one or more sides of the battery module 300, for example, the left and right sides, front and back sides, or all four sides of the battery module 300 can be provided with elastic film bags 21.

[0054] In the case where multiple battery modules 300 are installed within the same battery pack 01, if the multiple battery modules 300 are arranged side by side, for example... Figure 1 The two battery modules 300 arranged side by side shown can each have an independent auxiliary temperature control device, or multiple battery modules 300 can share the same liquid reservoir 23 for their auxiliary temperature control devices. The specific configuration can be made according to the actual needs of those skilled in the art.

[0055] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. An auxiliary temperature control device for a battery pack, the battery pack comprising a housing and a battery module disposed within the housing; characterized in that, The auxiliary temperature control device includes: An elastic film bag; the elastic film bag is disposed between the battery module and the inner wall of the housing within the battery pack; A liquid reservoir; the liquid reservoir is used to store a liquid working fluid with high thermal conductivity; and A delivery pump; the delivery pump is connected between the elastic membrane bag and the liquid reservoir via a pipeline, and is used to pump the liquid working medium bidirectionally between the elastic membrane bag and the liquid reservoir; The elastic membrane bag is adapted to expand to contact the inner wall of the battery module and the housing when the liquid working medium is filled, so that the battery module can accelerate heat dissipation to the housing through the liquid working medium; the elastic membrane bag is adapted to hinder air convection between the inner wall of the battery module and the housing after the liquid working medium is extracted.

2. The auxiliary temperature control device as described in claim 1, characterized in that, The elastic membrane bag is installed on the side of the battery module, so that the elastic membrane bag wrinkles and adheres to the side of the battery module after the liquid working medium is extracted; the elastic membrane bag expands towards the inner wall of the shell until it contacts the liquid working medium when it is filled.

3. The auxiliary temperature control device as described in claim 1, characterized in that, The elastic membrane bag is installed on the inner wall of the housing, so that the elastic membrane bag wrinkles and adheres to the inner wall of the housing after the liquid working medium is extracted; the elastic membrane bag expands towards the side of the battery module until it contacts the liquid working medium when it is filled.

4. The auxiliary temperature control device as described in claim 1, characterized in that, The elastic membrane bag is installed in the gap between the battery module and the inner wall of the housing, and the elastic membrane bag curls up after the liquid working fluid is extracted.

5. The auxiliary temperature control device as described in claim 4, characterized in that, The elastic membrane bag is provided with multiple interconnected air chambers. After the liquid working fluid is extracted, the elastic membrane bag forms an irregular curl through the air chambers.

6. The auxiliary temperature control device as described in claim 5, characterized in that, The elastic membrane bag is provided with a plurality of air chambers evenly arranged along its width; and / or, the elastic membrane bag is provided with a plurality of air chambers evenly arranged along its height.

7. The auxiliary temperature control device as described in claim 5, characterized in that, The elastic membrane bag is processed to obtain the air chamber through hot pressing, high-frequency welding or bonding processes.

8. The auxiliary temperature control device as described in any one of claims 1-7, characterized in that, The liquid reservoir is disposed on the top of the battery module. The liquid reservoir includes a rigid outer shell and a soft container bag disposed inside the rigid outer shell. The liquid working fluid is stored in the soft container bag. The rigid outer shell is fixedly connected to the inner wall of the housing.

9. The auxiliary temperature control device as described in claim 1, characterized in that, The auxiliary temperature control device also includes an electronic control board, which is electrically connected to the delivery pump; The electronic control board is adapted to receive control signals based on the temperature changes of the battery module, and to control the start, stop and directional control of the delivery pump according to the received control signals.

10. A residential energy storage device, characterized in that, The device includes a housing, a plurality of battery cells, and an auxiliary temperature control device as described in any one of claims 1-9; the plurality of battery cells form at least one battery module, the battery module is installed inside the housing to form a battery pack; the auxiliary temperature control device is installed between at least one side of the battery module and the inner wall of the housing.

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