A battery device, an electric device, and an energy storage device

Abstract

The application provides a battery device, a power utilization device and an energy storage device, relates to the technical field of batteries, and comprises a plurality of cell units, the cell units comprising a main cell, an auxiliary cell, a first heat exchange member and a second heat exchange member; the main cell and the auxiliary cell are connected in parallel, the rated capacity of the main cell is higher than that of the auxiliary cell, and the rated discharge rate of the auxiliary cell is greater than that of the main cell; the first heat exchange member is attached to the surface of the main cell, the second heat exchange member is attached to the surface of the auxiliary cell, the first heat exchange member is provided with a first flow channel, the second heat exchange member is provided with a second flow channel, the second flow channel is isolated from the first flow channel, and at least one of the flow and the temperature of the heat exchange medium is independently adjusted in the first flow channel and the second flow channel. The application has the effect of improving the consistency of the temperatures of the main cell and the auxiliary cell by cooling the main cell and the auxiliary cell respectively.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery device, electrical equipment, and energy storage device. Background Technology

[0002] With the rapid development of large-scale energy storage technology, single-cell systems can hardly meet the dual requirements of high energy density and high power density simultaneously. Hyperhybrid cell technology has emerged to address this need, featuring a primary and secondary cell architecture. Hyperhybrid cells typically consist of a high-energy-density primary cell and a high-power-density secondary cell connected in parallel or series, and have been widely used in energy storage power stations.

[0003] Uneven temperature distribution between the two cells in a super-hybrid battery cell accelerates cell aging and reduces usable capacity more quickly.

[0004] The above statements are for the purpose of providing background information in relation to this application only and do not necessarily constitute prior art. Utility Model Content

[0005] In view of this, the purpose of this application is to provide a battery device, electrical equipment and energy storage device to solve the technical problem of large temperature difference between main and auxiliary battery cells in the prior art.

[0006] To achieve at least one of the above objectives, this application provides the following technical solution:

[0007] In a first aspect, this application provides a battery device, including a main battery cell, an auxiliary battery cell, a first heat exchanger, and a second heat exchanger; the main battery cell and the auxiliary battery cell are connected in parallel, the rated capacity of the main battery cell is higher than the rated capacity of the auxiliary battery cell, and the rated discharge rate of the auxiliary battery cell is greater than the rated discharge rate of the main battery cell; the first heat exchanger is attached to the surface of the main battery cell, and the second heat exchanger is attached to the surface of the auxiliary battery cell; the first heat exchanger is provided with a first flow channel, and the second heat exchanger is provided with a second flow channel; the second flow channel is isolated from the first flow channel; heat exchange medium is provided in both the first and second flow channels, and at least one of the flow rate and temperature of the heat exchange medium can be independently adjusted.

[0008] In the above technical solution, by independently adjusting the heat exchange efficiency between the first heat exchanger and the main battery cell, and the heat exchange efficiency between the second heat exchanger and the auxiliary battery cell, heat exchange is performed on the main battery cell and the auxiliary battery cell respectively according to their temperature states. This achieves one-to-one independent thermal management of the main battery cell and the auxiliary battery cell, reducing energy loss due to over-cooling. It also facilitates rapid cooling of the auxiliary battery cell, reduces the temperature difference between the main battery cell and the auxiliary battery cell, improves the temperature consistency between the main battery cell and the auxiliary battery cell, and extends the cycle life of the super-hybrid battery cell module.

[0009] The heat exchange efficiency between the first heat exchanger and the main battery cell, and the non-interference between the second heat exchanger and the auxiliary battery cell, allow for setting the optimal operating temperature range for the main battery cell and the auxiliary battery cell respectively.

[0010] In some embodiments, the second heat exchanger is attached to the larger surface of the auxiliary battery core, and the larger surface of the auxiliary battery core is the surface of the auxiliary battery core with an area not less than the other surfaces.

[0011] In the above technical solution, the larger the contact area between the second heat exchanger and the auxiliary battery, the higher the heat exchange efficiency between the second heat exchanger and the auxiliary battery, which helps the heat of the auxiliary battery to be quickly transferred to the second heat exchanger and helps to reduce the temperature fluctuation of the auxiliary battery.

[0012] In some embodiments, the second heat exchanger further includes a second thermally conductive layer, which is attached to the surface of the auxiliary battery cell and is located between the second flow channel and the auxiliary battery cell.

[0013] In the above technical solution, by setting a second heat-conducting layer, when the auxiliary battery cell heats up, the heat can be quickly transferred to the second heat-conducting layer, which has the effect of reducing the temperature fluctuation range of the auxiliary battery cell.

[0014] In some embodiments, the main battery cell and the auxiliary battery cell are stacked, and the second thermal conductive layer is located on the side of the auxiliary battery cell away from the main battery cell.

[0015] In the above technical solution, by attaching the main battery and the second heat-conducting layer to the two sides of the auxiliary battery respectively, the main battery is used as a heat storage unit, and part of the heat of the auxiliary battery is transferred to the main battery, thereby reducing the temperature rise of the auxiliary battery when it is operating at high power.

[0016] In some embodiments, the first heat exchanger further includes a first thermally conductive layer, which is attached to the surface of the main battery cell and is located between the first flow channel and the main battery cell.

[0017] In the above technical solution, the setting of the first heat-conducting layer improves the heat conduction efficiency between the first heat exchanger and the main battery cell, which helps to control the temperature stability of the main battery cell.

[0018] In some embodiments, the main battery cell and the auxiliary battery cell are stacked, and the first thermal conductive layer is located on the side of the main battery cell away from the auxiliary battery cell.

[0019] In the above technical solution, by setting the first heat-conducting layer on the side of the main battery cell away from the auxiliary battery cell, the first heat-conducting layer transfers most of the heat of the main battery cell to the first heat exchanger, which has the effect of reducing heat conduction to the adjacent auxiliary battery cell and improving the temperature consistency between the main battery cell and the auxiliary battery cell.

[0020] In some embodiments, the main battery cell and the auxiliary battery cell are stacked; the battery cell unit also includes a heat insulation element located on the side of the main battery cell away from the auxiliary battery cell.

[0021] In the above technical solution, the heat transfer between two adjacent battery cells is reduced by the installation of heat insulation components.

[0022] In some embodiments, the battery cell unit further includes a unidirectional heat conduction element located between the main battery cell and the auxiliary battery cell. The forward thermal conductivity of the unidirectional heat conduction element is greater than the reverse thermal conductivity. The forward thermal conductivity is the thermal conductivity of the auxiliary battery cell towards the main battery cell, and the reverse thermal conductivity is the thermal conductivity of the main battery cell towards the auxiliary battery cell.

[0023] In the above technical solution, by setting up a unidirectional heat conduction element, the main battery cell is used as a thermal buffer. During pulse discharge, the instantaneous heat generated by the auxiliary battery cell is quickly transferred to the main battery cell through the unidirectional heat conduction element. The heat stored in the main battery cell is used to effectively suppress the temperature spike of the auxiliary battery cell.

[0024] In some embodiments, the first heat exchanger is located on the side of the main battery cell away from the unidirectional heat conduction element, and the second heat exchanger is located on the side of the auxiliary battery cell away from the unidirectional heat conduction element.

[0025] In the above technical solution, the heat of the main battery cell is transferred to the auxiliary battery cell by sequentially arranging the first heat exchanger, the main battery cell, the unidirectional heat conduction element, the auxiliary battery cell, and the second heat exchanger. The interference between the first heat exchanger and the second heat exchanger is small, which helps to improve the temperature consistency of the entire battery cell group.

[0026] In some embodiments, the main battery cell is a lithium iron phosphate battery cell or a ternary battery cell; the auxiliary battery cell is a lithium titanate battery cell.

[0027] In some embodiments, the battery device further includes a first temperature sensor, a second temperature sensor, a regulating component, and a control unit; the first temperature sensor monitors the temperature of the main battery cell; the second temperature sensor monitors the temperature of the auxiliary battery cell; the regulating component is used to regulate the heat exchange efficiency of the heat exchange medium in the second flow channel; the control unit is signal-connected to the regulating component, the first temperature sensor, and the second temperature sensor; when the control unit receives the temperature monitored by the first temperature sensor and the second temperature sensor and the temperature meets the set conditions, it sends a first signal to the regulating component; when the regulating component receives the first signal, it regulates the heat exchange efficiency of the heat exchange medium in the second flow channel.

[0028] In the above technical solution, the control component receives the signal from the temperature sensor and sends a signal to the control component, thereby realizing the independent control of the heat exchange efficiency between the second heat exchanger and the auxiliary battery cell based on the temperature changes of the main battery cell and the auxiliary battery cell.

[0029] In some embodiments, the control component includes at least one of a temperature regulator and a flow regulator, wherein the flow regulator is used to control the flow rate of the heat exchange medium in the heat exchange channel, and the temperature regulator is used to control the temperature of the heat exchange medium in the heat exchange channel.

[0030] In the above technical solution, by setting temperature and flow regulating components, the flow rate of the heat exchange medium in the first flow channel can be switched in real time and the temperature of the heat exchange medium can be dynamically fine-tuned, which can quickly respond to the temperature fluctuation caused by changes in the charging and discharging load of the auxiliary battery cell.

[0031] Secondly, embodiments of this application also provide an energy storage device, including the aforementioned battery device, which is used to store or provide electrical energy.

[0032] The above technical solution improves the situation of large temperature difference between the main and auxiliary battery cells, thereby reducing the problem of temperature inconsistency between the main and auxiliary battery cells.

[0033] Thirdly, embodiments of this application also provide an electrical device, including a power conversion device and the aforementioned battery device, wherein the power conversion device is used to electrically connect to a power generation device.

[0034] The above technical solution improves the situation of large temperature difference between the main and auxiliary battery cells, thereby reducing the problem of temperature inconsistency between the main and auxiliary battery cells. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of a vehicle provided according to some embodiments of this application;

[0037] Figure 2 This is an exploded structural diagram of a battery device according to some embodiments of this application;

[0038] Figure 3 This is a schematic diagram of the stacked structure of the main battery cell and the auxiliary battery cell in one embodiment;

[0039] Figure 4 This is a schematic diagram of a structure in one embodiment where the first heat exchanger exchanges heat with the main battery cell and the second heat exchanger exchanges heat with the auxiliary battery cell;

[0040] Figure 5 This is a schematic diagram of the structure of the first heat-conducting layer and the main battery cell, and the second heat-conducting layer and the auxiliary battery cell in one embodiment.

[0041] Figure 6 This is a schematic diagram of the structure of the heat insulation component and the main battery cell in one embodiment;

[0042] Figure 7 This is a schematic diagram of a unidirectional heat conduction component located between the main battery cell and the auxiliary battery cell in one embodiment.

[0043] Figure 8 This is a schematic diagram of the structure of the heat insulation component, the unidirectional heat conduction component, and the main battery cell in one embodiment;

[0044] Figure 9 This is a schematic diagram illustrating the relationship between the temperature sensor and the control unit in one embodiment.

[0045] Figure 10 This is a structural schematic diagram illustrating the relationship between the heat insulation component and the unidirectional heat conduction component in one embodiment.

[0046] The attached figures are labeled as follows:

[0047] 1000, Vehicle; 100, Battery unit; 110, Battery unit assembly; 120, Housing; 1201, First housing; 1202, Second housing; 200, Controller; 300, Motor;

[0048] 1. Main battery cell; 11. First side; 2. Auxiliary battery cell; 21. Second side; 3. First heat exchanger; 31. First flow channel; 32. First thermal conductive layer; 4. Second heat exchanger; 41. Second flow channel; 42. Second thermal conductive layer; 5. Thermal insulation; 6. Unidirectional thermal conductive element;

[0049] 71. First temperature sensor; 72. Second temperature sensor; 73. Control component; 74. Control unit. Detailed Implementation

[0050] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0051] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and the foregoing description of this application are intended to cover non-exclusive inclusion.

[0052] The term "embodiment" as used in this application means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0053] The specific term "exemplary" used in this application means "serving as an example, embodiment, or illustration." Any embodiment illustrated as "exemplary" is not necessarily to be construed as superior or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0054] In the description of this application, the technical terms "first", "second", "third", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0055] In the description of this application, the technical term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0056] In the description of this application, the technical terms "upper", "lower", "inner", "outer", "front", "back", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship in the working state of this application. They 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. Therefore, they should not be construed as limitations on this application.

[0057] In the description of this application, unless otherwise expressly specified and limited, the technical terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed 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 based on the specific circumstances.

[0058] In the description of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is 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 can mean that the first feature is 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.

[0059] The terms "parallel" and "perpendicular" used in this application can mean not only perfectly parallel and perpendicular, but also have a certain margin of error; for example, if the angle between the two is greater than or equal to 0° and less than or equal to 5°, they are considered to be parallel; if the angle between the two is greater than or equal to 85° and less than or equal to 95°, they are considered to be perpendicular.

[0060] In the description of this application, "multiple" means two or more (including two), unless otherwise expressly and specifically defined.

[0061] In the description of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, and other dimensions of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0062] As part of the inventive concept of this application, before describing the embodiments of this application, it is necessary to analyze the reasons for the large temperature difference between the main and auxiliary cells in the related art, and obtain the technical solution of the embodiments of this application through reasonable analysis.

[0063] In related technologies, a super-hybrid battery cell consists of a high-energy-density main cell and a high-power-density auxiliary cell connected in parallel or series. The main cell can be a lithium iron phosphate cell or a high-nickel ternary cell, and the auxiliary cell can be a lithium titanate cell. Due to significant differences in material systems, internal resistance, thermal properties, and heat generation rates during charging and discharging between the main and auxiliary cells, the temperature field distribution within and between the two cells is extremely uneven during charging and discharging, especially under high-rate conditions. This temperature inconsistency not only accelerates cell aging and leads to rapid capacity decay but may also trigger a chain reaction of thermal runaway, seriously threatening the safety and cycle life of the battery system.

[0064] Existing cell thermal management technologies target the overall temperature control of a single type of cell, employing a uniform heat dissipation or heating strategy. They do not fully consider the differences in the main and auxiliary structures and heat generation characteristics of hybrid cells, and therefore cannot achieve precise temperature matching between the main and auxiliary cells, resulting in large deviations in temperature consistency.

[0065] This application discloses a battery device, including a main battery cell, an auxiliary battery cell, a first heat exchanger, and a second heat exchanger; the main battery cell and the auxiliary battery cell are connected in parallel, the rated capacity of the main battery cell is higher than the rated capacity of the auxiliary battery cell, and the rated discharge rate of the auxiliary battery cell is greater than the rated discharge rate of the main battery cell; the first heat exchanger is attached to the surface of the main battery cell, and the second heat exchanger is attached to the surface of the auxiliary battery cell; the first heat exchanger is provided with a first flow channel, and the second heat exchanger is provided with a second flow channel; the second flow channel is isolated from the first flow channel; heat exchange medium is provided in both the first and second flow channels, and at least one of the flow rate and temperature of the heat exchange medium can be independently adjusted.

[0066] By adjusting at least one of the flow rate or temperature of the heat exchange medium in the first flow channel, the heat exchange efficiency between the first heat exchanger and the main battery cell is adjusted. By adjusting at least one of the flow rate or temperature of the heat exchange medium in the second flow channel, the heat exchange efficiency between the second heat exchanger and the auxiliary battery cell is adjusted. Based on the temperature status of the main battery cell and the auxiliary battery cell, the first heat exchanger and the second heat exchanger are used to exchange heat between the main battery cell and the auxiliary battery cell respectively, thereby achieving one-to-one independent thermal management of the main battery cell and the auxiliary battery cell. This helps to reduce the temperature difference between the main battery cell and the auxiliary battery cell and improve the temperature consistency between the main battery cell and the auxiliary battery cell.

[0067] This application overcomes the coupling limitation of simultaneous heating and cooling of battery cells in traditional thermal management by thermally decoupling the physical structure. It enables on-demand heat dissipation, addressing the differentiated heat generation characteristics of the main and auxiliary cells in a hybrid battery cell due to their different material systems.

[0068] For auxiliary cells with high heat generation rates but potentially poor heat resistance, high-intensity rapid cooling is implemented; while for main cells with large heat capacity but relatively slow heat generation, gentle cooling is implemented. This structure effectively reduces the temperature difference between the main and auxiliary cells, improves the consistency of the temperature field, and extends the cycle life of the super-hybrid cell module. Independent cooling of the main and auxiliary cells reduces energy loss caused by over-cooling.

[0069] The technical solutions provided in this application are applicable to electrical devices that use battery devices as power sources and energy storage devices that use battery devices as energy storage elements. Electrical devices can be vehicles, ships, spacecraft, etc. Energy storage devices include, but are not limited to, energy storage containers, energy storage cabinets, etc.

[0070] For ease of description, this application uses the application of a battery device in a vehicle as an example for illustration.

[0071] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle according to some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0072] In some embodiments, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0073] In some embodiments, the battery device 100 can also be used in an energy storage power station, which can smooth out grid peak and valley, absorb new energy power generation, withstand high and low temperatures and frequent charging and discharging conditions, balance construction costs and long-term operation and maintenance life, and adapt to grid peak and frequency regulation scenarios.

[0074] The battery unit 100 can also serve as a backup uninterruptible power supply for data centers. It can instantly respond to power outages and switch over, ensuring the stable operation of servers and computing equipment. It is adaptable to a wide temperature range in the data center environment, reducing the risk of downtime and replacement costs.

[0075] The battery unit is compatible with energy storage charging piles, buffering grid load and storing and releasing energy during peak periods. It supports high-power fast charging requirements, has a long cycle life and a high safety factor, and can alleviate the pressure of grid expansion. It is suitable for high-power energy replenishment deployment scenarios such as residential areas and highway service areas.

[0076] refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery device according to some embodiments of this application. The battery device includes a housing 120 and a battery device assembly 110. The housing 120 has a receiving cavity, and the battery device assembly 110 is received within the receiving cavity of the housing 120.

[0077] In some embodiments, a battery apparatus may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or in a mixed configuration via a busbar.

[0078] In some embodiments, the battery device assembly is typically formed by arranging multiple battery devices.

[0079] As an example, the battery device assembly can be a battery module, which consists of multiple battery devices arranged and fixed together to form an independent module.

[0080] As an example, a battery module can be formed by bundling multiple battery devices together with cable ties.

[0081] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more battery device components housed within the housing.

[0082] As an example, the battery assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0083] As an example, the battery assembly can also be housed in the housing by directly fixing multiple battery devices to the housing.

[0084] As an example, such as Figure 2 As shown, the housing 120 may include a first housing 1201 and a second housing 1202. The first housing 1201 and the second housing 1202 are fastened together to form a closed space inside the housing 120 to house the battery assembly 110. Here, "closed" refers to covering or closing, which can be sealed or unsealed. The first housing 1201 may be a top cover or a bottom plate.

[0085] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the battery assembly.

[0086] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0087] In some embodiments, the battery device can be a secondary battery, which refers to a battery device that can be used again after being discharged by recharging to activate the active materials.

[0088] As an example, the battery device can be a prismatic battery device or a battery device of other shapes with a large surface area. Prismatic battery devices include square-shell battery devices with a large surface area, blade-shaped battery devices, and multi-prismatic batteries, such as hexagonal prismatic batteries. The embodiments of this application are not limited in this respect.

[0089] Reference Figure 4Therefore, this application provides a battery device including a plurality of battery cell units, wherein the battery cell unit includes a main battery cell 1, an auxiliary battery cell 2, a first heat exchanger 3 and a second heat exchanger 4.

[0090] Specifically, the battery device includes multiple cell units, the number of which can be determined as needed. In addition to multiple cell units, the battery device may also include several main cells and several auxiliary cells.

[0091] Reference Figure 3 For example, the main battery cell 1 and auxiliary battery cell 2 in the battery device are connected in parallel. The specific number of main battery cells 1 and auxiliary battery cells 2 connected in parallel can be determined according to design needs. In this embodiment, the parallel connection method of main battery cells 1 and auxiliary battery cells 2 is that several main battery cells 1 and several auxiliary battery cells 2 in the same module are connected in parallel in the same direction to form a parallel unit. Multiple parallel units are then connected in series to form a battery cluster.

[0092] In another embodiment, multiple main battery cells 1 are connected in series to form a main string branch, and multiple auxiliary battery cells 2 are connected in series to form an auxiliary string branch. The two ends of the main string branch and the auxiliary string branch are then connected in parallel for output.

[0093] In another embodiment, multiple main cells 1 and multiple auxiliary cells 2 are arranged in an alternating pattern, connected in series at intervals, and coupled in parallel across nodes.

[0094] The rated capacity of the main cell 1 is higher than that of the auxiliary cell 2. The rated capacity is the maximum amount of electricity that the battery can theoretically release under the conditions of standard specified temperature, standard discharge current and termination voltage.

[0095] The rated discharge rate of auxiliary cell 2 is greater than that of main cell 1. The rated discharge rate is the rated current multiple for long-term stable and safe discharge of the cell, and represents the upper limit of safe discharge under normal battery operating conditions. Main cell 1 generates a large amount of heat, but its heat generation state is stable. Auxiliary cell 2 has a high peak power and exhibits pulsed intermittent heat generation characteristics.

[0096] For example, the main cell 1 is a lithium iron phosphate cell, and the auxiliary cell 2 is a lithium titanate cell. In another embodiment, the main cell 1 is a lithium iron phosphate cell, and the auxiliary cell 2 is a ternary lithium cell. In yet another embodiment, the main cell 1 is a lithium iron phosphate cell, and the auxiliary cell 2 is a sodium-ion cell.

[0097] The first heat exchanger 3 is attached to the surface of the main battery cell 1. The first heat exchanger 3 can be attached to any surface of the main battery cell 1. On the one hand, the first heat exchanger 3 can be attached to areas on the surface of the main battery cell 1 where no electrical components are installed. The electrical components include at least one of temperature sensors and voltage sensors. On the other hand, when the first heat exchanger 3 is attached to the surface of the main battery cell 1, it can be arranged to avoid the electrical components. A thermal conduction connection is formed between the main battery cell 1 and the first heat exchanger 3. The heat generated by the main battery cell 1 during operation can be conducted to the first heat exchanger 3 to achieve heat exchange and dissipation of the main battery cell 1.

[0098] The second heat exchanger 4 is attached to the surface of the auxiliary battery cell 2. The second heat exchanger 4 can be attached to any surface of the auxiliary battery cell 2. On one hand, the second heat exchanger 4 can be attached to areas on the surface of the auxiliary battery cell 2 where no electrical components are located, including at least one of a temperature sensor and a voltage sensor. On the other hand, when the second heat exchanger 4 is attached to the surface of the auxiliary battery cell 2, it can be positioned to avoid direct contact with electrical components. A thermal conduction connection is formed between the auxiliary battery cell 2 and the second heat exchanger 4. The heat generated during the operation of the auxiliary battery cell 2 can be conducted to the second heat exchanger 4 to achieve heat dissipation from the auxiliary battery cell 2.

[0099] The first heat exchanger 3 is provided with a first flow channel 31, and the second heat exchanger 4 is provided with a second flow channel 41. The second flow channel 41 is isolated from the first flow channel 31. Both the first flow channel 31 and the second flow channel 41 are provided with heat exchange medium, and at least one of the heat exchange medium flow rate and temperature can be independently adjusted.

[0100] The heat exchange medium is a medium capable of exchanging heat with the first heat exchanger 3 and the second heat exchanger 4. The heat exchange medium includes, but is not limited to, liquid media and gaseous media. In this embodiment, the heat exchange medium is a liquid media. The heat exchange medium includes, but is not limited to, ethylene glycol, fluorinated liquid, hydrocarbon insulating oil, or other liquid media.

[0101] The first heat exchanger 3 has a first flow channel 31 inside. The first flow channel 31 allows the heat exchange medium to flow in a directional manner inside it. The first flow channel 31 connects the first liquid inlet pipe and the first liquid outlet pipe. After the heat exchange medium enters the first flow channel 31 from the first liquid inlet pipe, it flows along the first flow channel 31 and flows out from the first liquid outlet pipe, carrying away the heat of the first heat exchanger 3.

[0102] The second heat exchanger 4 has a second flow channel 41 inside, which allows the heat exchange medium to flow in a directional manner. The second flow channel 41 is connected to the second liquid inlet pipe and the second liquid outlet pipe. After the heat exchange medium enters the second flow channel 41 from the second liquid inlet pipe, it flows along the second flow channel 41 and flows out from the second liquid outlet pipe, carrying away the heat of the second heat exchanger 4.

[0103] The second flow channel 41 is independently configured relative to the first flow channel 31. In this embodiment, the flow rate and temperature of the heat exchange medium in the first flow channel 31 and the second flow channel 41 can be adjusted independently. The greater the flow rate of the heat exchange medium, the more heat it can remove per unit time; the lower the temperature of the heat exchange medium, the more heat it can remove per unit time.

[0104] In another embodiment, the flow rate of the heat exchange medium in the first flow channel 31 and the second flow channel 41 can be adjusted independently. In another embodiment, the temperature of the heat exchange medium in the first flow channel 31 and the second flow channel 41 can be adjusted independently.

[0105] When the main battery cell 1 stably exchanges energy with the outside environment, the heat exchange medium in the first flow channel 31 flows stably through the first heat exchanger 3. The heat exchange medium in the first flow channel 31 carries away the heat from the first heat exchanger 3, and the first heat exchanger 3 continuously exchanges heat with the main battery cell 1, maintaining the stable temperature of the main battery cell 1 during operation. When the auxiliary battery cell 2 exchanges energy with the outside environment at high power, the auxiliary battery cell 2 generates a large amount of heat in a short time, and the temperature of the auxiliary battery cell 2 rises rapidly. At this time, the flow rate of the heat exchange medium in the second flow channel 41 increases, and the temperature of the heat exchange medium entering the second flow channel 41 decreases. This allows the heat exchange medium in the second flow channel 41 to quickly carry away a large amount of heat when it flows out of the second heat exchanger 4, achieving rapid cooling of the auxiliary battery cell 2 by the second heat exchanger 4 and reducing the temperature fluctuation range of the auxiliary battery cell 2.

[0106] To address the different heat generation characteristics of the main battery cell 1 and the auxiliary battery cell 2 due to their different material systems, the main battery cell 1 and the auxiliary battery cell 2 are cooled as needed through the first heat exchanger 3 and the second heat exchanger 4. For the auxiliary battery cell 2, which has a fast heat generation rate but may have poor heat resistance, high-intensity rapid cooling is implemented; while for the main battery cell 1, which has a large heat capacity but relatively slow heat generation, gentle cooling is implemented.

[0107] By controlling the temperature difference between the main battery cell 1 and the auxiliary battery cell 2 within the set temperature difference, the consistency of the temperature field is improved, the energy loss caused by excessive cooling is reduced, and the cycle life of the super hybrid battery cell module is significantly extended.

[0108] Compared to controlling the temperature of all battery cells within a single temperature range, the heat exchange between the first heat exchanger and the main battery cell, as well as between the second heat exchanger and the auxiliary battery cell, do not interfere with each other. The optimal operating temperature ranges for the main battery cell and the auxiliary battery cell can be set separately. By lowering the optimal operating temperature of the auxiliary battery cell, it helps to reduce the temperature difference between the auxiliary battery cell and the main battery cell when the auxiliary battery cell is operating at high power.

[0109] Reference Figure 2 as well as Figure 3 As an optional solution, the second heat exchanger 4 is attached to the large surface of the auxiliary battery 2, and the large surface of the auxiliary battery 2 is the surface of the auxiliary battery 2 with an area not less than the other surfaces.

[0110] For example, the larger surface of the auxiliary battery cell 2 is the second surface 21, and the area of ​​the second surface 21 is not less than the area of ​​the remaining surfaces of the auxiliary battery cell 2. The auxiliary battery cell 2 may have a surface with an area equal to that of the second surface 21. In this embodiment, the auxiliary battery cell 2 is a prismatic battery cell, and the larger surface of the auxiliary battery cell 2 is one of its surfaces in the thickness direction.

[0111] The larger the contact area between the second heat exchanger 4 and the auxiliary battery 2, the higher the heat exchange efficiency between them. This helps the heat from the auxiliary battery 2 to be quickly transferred to the second heat exchanger 4, where it is carried away by the heat exchange medium in the second flow channel 41. This reduces the temperature fluctuation of the auxiliary battery 2 and extends its cycle life.

[0112] Furthermore, the first heat exchanger 3 is attached to the large surface of the main battery cell 1, and the large surface of the main battery cell 1 is the surface of the main battery cell 1 with an area not less than the other surfaces.

[0113] For example, the larger surface of the main battery cell 1 is the first surface 11, and the area of ​​the first surface 11 is not less than the area of ​​the remaining surfaces of the main battery cell 1. The main battery cell 1 may have a surface with an area equal to that of the first surface 11. The larger the contact area between the first heat exchanger 3 and the main battery cell 1, the higher the heat exchange efficiency between the first heat exchanger 3 and the main battery cell 1, which helps the heat of the main battery cell 1 to be quickly transferred to the first heat exchanger 3, and then carried away by the heat exchange medium in the first flow channel 31, thereby improving the temperature stability of the main battery cell 1.

[0114] Reference Figure 5 As an optional solution, the second heat exchanger 4 also includes a second heat-conducting layer 42, which is attached to the surface of the auxiliary battery cell 2 and is located between the second flow channel 41 and the auxiliary battery cell 2.

[0115] Specifically, the second heat-conducting layer 42 can fill the microscopic gaps at the contact surface between the second heat exchanger 4 and the auxiliary battery 2, reduce the interfacial contact thermal resistance, and effectively improve the thermal conductivity between the second heat exchanger 4 and the auxiliary battery 2.

[0116] The second thermally conductive layer 42 can be a phase change thermally conductive layer. Specifically, the material of the second thermally conductive layer 42 is one of paraffin-based phase change materials, fatty acid-based phase change materials, or polyethylene glycol-based phase change materials.

[0117] The second heat-conducting layer 42 can both conduct heat between the auxiliary battery cell 2 and the second heat exchanger 4 and store heat. When the auxiliary battery cell 2 heats up rapidly, the heat can be quickly transferred to the second heat-conducting layer 42, and then the heat exchange medium in the second flow channel 41 will carry away the heat stored in the second heat-conducting layer 42, which helps to reduce the temperature fluctuation of the auxiliary battery cell 2. It can also take advantage of its heat absorption when the heat is high and slow release when the heat is low to help keep the auxiliary battery cell 2 in a constant temperature state, which is suitable for battery constant temperature thermal management.

[0118] In another embodiment, the second thermally conductive layer 42 is any one or more composites of thermally conductive silicone pad, thermally conductive grease, graphite thermally conductive sheet, thermally conductive gel, and insulating thermally conductive foam.

[0119] Reference Figure 5 As an alternative, the main battery cell 1 and the auxiliary battery cell 2 are stacked, with the second thermal conductive layer 42 located on the side of the auxiliary battery cell 2 away from the main battery cell 1.

[0120] Specifically, this embodiment uses a prismatic battery with main cell 1 and auxiliary cell 2 as an example. Main cell 1 and auxiliary cell 2 are stacked along a first direction, which is the thickness direction of auxiliary cell 2, and the thickness direction of main cell 1 is also along the first direction. Along the first direction, the orthographic projection of main cell 1 is located on auxiliary cell 2, and the thicknesses of main cell 1 and auxiliary cell 2 are different.

[0121] Along the first direction, the first heat exchanger 3, the main battery cell 1, the auxiliary battery cell 2, the second heat-conducting layer 42 and the second heat exchanger 4 are arranged in sequence, and the auxiliary battery cell 2 is attached to the main battery cell 1 and the second heat-conducting layer 42 on both sides along the first direction.

[0122] When the auxiliary battery cell 2 heats up rapidly, some of the heat from the auxiliary battery cell 2 is transferred to the second heat-conducting layer 42, and some of the heat is transferred to the main battery cell 1. The main battery cell 1 is used as a heat storage unit, and the heat from the auxiliary battery cell 2 is quickly transferred outward, which further reduces the temperature rise of the auxiliary battery cell 2 when it is working at high power, and helps to fully release the maximum rated power of the auxiliary battery cell 2.

[0123] In another embodiment, along the first direction, the first heat exchanger 3, the main battery cell 1, the second heat exchanger 4, the second thermal conductive layer 42, and the auxiliary battery cell 2 are arranged sequentially.

[0124] Reference Figure 5 As an optional solution, the first heat exchanger 3 also includes a first thermally conductive layer 32, which is attached to the surface of the main battery cell 1 and is located between the first flow channel 31 and the main battery cell 1.

[0125] Specifically, the first thermally conductive layer 32 can fill the microscopic gaps between the contact surface of the first heat exchanger 3 and the main battery cell 1, reduce the interfacial contact thermal resistance, and effectively improve the thermal conductivity between the first heat exchanger 3 and the main battery cell 1.

[0126] The first thermally conductive layer 32 can be a phase change thermally conductive layer. Specifically, the material of the first thermally conductive layer 32 is one of paraffin-based phase change materials, fatty acid-based phase change materials, or polyethylene glycol-based phase change materials.

[0127] The first thermal conductive layer 32 utilizes its properties of absorbing heat when it is hot and releasing heat slowly when it is cold, which also helps to keep the main cell 1 in a constant temperature state and is suitable for constant temperature thermal management of the battery.

[0128] In another embodiment, the first thermally conductive layer 32 is any one or more composites of thermally conductive silicone pad, thermally conductive grease, graphite thermally conductive sheet, thermally conductive gel, and insulating thermally conductive foam.

[0129] Reference Figure 5 As an alternative, the main battery cell 1 and the auxiliary battery cell 2 are stacked, with the first thermal conductive layer 32 located on the side of the main battery cell 1 away from the auxiliary battery cell 2.

[0130] Specifically, along the first direction, the first heat exchanger 3, the first heat-conducting layer 32, the main battery cell 1, the auxiliary battery cell 2, and the second heat exchanger 4 are arranged sequentially.

[0131] When the main battery cell 1 generates a lot of heat, the first heat-conducting layer 32 transfers most of the heat from the main battery cell 1 to the first heat exchanger 3, which can quickly conduct away the heat from the main battery cell 1 and reduce the heat conduction to the adjacent auxiliary battery cell 2. The operating temperature of the auxiliary battery cell 2 is stable, which improves the temperature consistency and service life of the main battery cell 1 and the auxiliary battery cell 2.

[0132] In another embodiment, along the first direction, the main battery cell 1, the first thermal conductive layer 32, the first heat exchanger 3, the auxiliary battery cell 2, and the second heat exchanger 4 are arranged sequentially.

[0133] In another embodiment, along a first direction, the main battery cell 1, the first thermal conductive layer 32, the first heat exchanger 3, the auxiliary battery cell 2, the second thermal conductive layer 42, and the second heat exchanger 4 are arranged sequentially.

[0134] In another embodiment, along the first direction, the main battery cell 1, the first heat-conducting layer 32, the first heat exchanger 3, the second heat exchanger 4, the second heat-conducting layer 42, and the auxiliary battery cell 2 are arranged sequentially.

[0135] Reference Figure 6 As an alternative, the main battery cell 1 and the auxiliary battery cell 2 are stacked; the battery cell unit also includes a heat insulation component 5, which is located on the side of the main battery cell 1 away from the auxiliary battery cell 2.

[0136] Specifically, along the first direction, the battery cell unit includes a heat insulation component 5, a first heat exchange component 3, a main battery cell 1, an auxiliary battery cell 2, and a second heat exchange component 4 arranged in sequence. Two adjacent battery cell units include a heat insulation component 5, a first heat exchange component 3, a main battery cell 1, an auxiliary battery cell 2, a second heat exchange component 4, a heat insulation component 5, a first heat exchange component 3, a main battery cell 1, an auxiliary battery cell 2, and a second heat exchange component 4 arranged in sequence.

[0137] The heat insulation component 5 isolates the heat between adjacent battery cells, reducing heat transfer between them. Each battery cell forms an independent temperature control zone, allowing for individual heat exchange and temperature regulation of the main cell 1 and auxiliary cell 2 within the unit. Temperature interference between different cells is minimal, improving the overall temperature consistency of the battery pack. When any cell in a battery cell experiences abnormal heating or thermal runaway, it prevents heat from spreading to adjacent cells, reducing the risk of cascading thermal runaway and significantly improving the safety of the battery device. The independent heat exchange of each battery cell with mutual insulation reduces the impact of localized overheating on overall temperature control, ensuring a more even distribution of heat exchange load across all cells, extending the overall cycle life of the battery device, and reducing the aging rate.

[0138] In another embodiment, a battery cell unit includes a heat insulation component 5, a first heat exchange component 3, a main battery cell 1, a second heat exchange component 4, and an auxiliary battery cell 2 arranged sequentially.

[0139] In another embodiment, a battery cell unit includes a heat insulation component 5, a main battery cell 1, a first heat exchange component 3, a second heat exchange component 4, and an auxiliary battery cell 2 arranged sequentially.

[0140] Reference Figure 7 As an optional solution, the battery cell unit also includes a unidirectional heat conduction element 6, which is located between the main battery cell 1 and the auxiliary battery cell 2. The forward thermal conductivity of the unidirectional heat conduction element 6 is greater than the reverse thermal conductivity. The forward thermal conductivity is the thermal conductivity of the auxiliary battery cell 2 towards the main battery cell 1, and the reverse thermal conductivity is the thermal conductivity of the main battery cell 1 towards the auxiliary battery cell 2.

[0141] Specifically, the unidirectional heat-conducting element 6 is a composite of PCM phase change material and oriented graphite. In another embodiment, the unidirectional heat-conducting element 6 is a flexible unidirectional heat-conducting silicone pad internally doped with directional heat-conducting filler. In yet another embodiment, the unidirectional heat-conducting element 6 is a directional heat-conducting graphite sheet.

[0142] Along the first direction, the unidirectional heat conduction element 6 is located between the main battery cell 1 and the auxiliary battery cell 2. The forward thermal conductivity of the unidirectional heat conduction element 6 is greater than the reverse thermal conductivity. The larger the thermal conductivity, the higher the heat transfer efficiency; the smaller the thermal conductivity, the worse the heat transfer efficiency.

[0143] The unidirectional heat conduction element 6 can quickly conduct the heat of the auxiliary battery cell 2 to the main battery cell 1, while preventing the heat of the main battery cell 1 from being conducted to the auxiliary battery cell 2.

[0144] Auxiliary battery cell 2 generates heat at an extremely high rate during high-rate pulse discharge, potentially exceeding its safe temperature limit within a short period. Using a high-power cooling system to address this rapid temperature rise would be wasteful of energy and resources.

[0145] This application utilizes the unidirectional thermal conductivity of the heat-conducting element 6 to transfer heat from the auxiliary battery cell 2 to the main battery cell 1. Using the main battery cell 1 as a thermal buffer, during pulse discharge, the instantaneous heat generated by the auxiliary battery cell 2 is rapidly transferred to the main battery cell 1 via the unidirectional heat-conducting element 6. The main battery cell 1 stores this heat, effectively reducing the peak temperature of the auxiliary battery cell 2. The main battery cell 1 itself has a large heat capacity, so its temperature rise after absorbing this heat is small, preventing immediate overheating. After the pulse ends, the heat stored in the main battery cell 1 is slowly released using the first heat exchanger 3. This application achieves a redistribution of heat among the battery cell units without increasing additional energy consumption, further reducing the transient temperature difference between the main and auxiliary batteries and improving the thermal stability of the system under complex operating conditions.

[0146] If a one-way heat conduction element 6 is not installed between the main battery cell 1 and the auxiliary battery cell 2, some of the heat generated by the main battery cell 1 will be transferred to the auxiliary battery cell 2, causing the temperature of the auxiliary battery cell 2 to rise, which is not conducive to the temperature control of the auxiliary battery cell 2 and the suppression of peak temperature.

[0147] By setting up the unidirectional heat conduction element 6, when the auxiliary cell 2 is not operating at high power, the temperature of the auxiliary cell 2 can be controlled to be lower than that of the main cell 1. When the auxiliary cell 2 is operating at high power, it helps to reduce the temperature difference between the auxiliary cell 2 and the main cell 1, improve the temperature consistency of different cells in the battery device, and extend the service life of the cells.

[0148] Reference Figure 7 As an alternative, the first heat exchanger 3 is located on the side of the main battery cell 1 away from the unidirectional heat conduction element 6, and the second heat exchanger 4 is located on the side of the auxiliary battery cell 2 away from the unidirectional heat conduction element 6.

[0149] Specifically, along the first direction, the first heat exchanger 3, the main battery cell 1, the unidirectional heat conduction element 6, the auxiliary battery cell 2, and the second heat exchanger 4 are arranged sequentially.

[0150] The heat of the main battery cell 1 is carried away by the heat exchange medium in the first flow channel 31 on the first heat exchanger 3. Part of the heat of the auxiliary battery cell 2 is carried away by the heat exchange medium in the second flow channel 41 on the second heat exchanger 4. Part of the heat of the auxiliary battery cell 2 is also transferred to the main battery cell 1 through the unidirectional heat conduction element 6. This reduces the heat transfer from the main battery cell 1 to the auxiliary battery cell 2. The interference between the first heat exchanger 3 and the second heat exchanger 4 is small, which helps to improve the temperature consistency of the entire battery cell group.

[0151] In another embodiment, along a first direction, the first heat exchanger 3, the first heat-conducting layer 32, the main battery cell 1, the unidirectional heat-conducting element 6, the auxiliary battery cell 2, the second heat-conducting layer 42, and the second heat exchanger 4 are arranged sequentially.

[0152] In another embodiment, along the first direction, the heat insulation element 5, the first heat exchange element 3, the first heat conduction layer 32, the main battery cell 1, the unidirectional heat conduction element 6, the auxiliary battery cell 2, the second heat conduction layer 42, and the second heat exchange element 4 are arranged sequentially.

[0153] Reference Figure 3 As an optional solution, it includes multiple main battery cells 1 and multiple auxiliary battery cells 2; the multiple main battery cells 1 include at least one main battery cell group, and the main battery cell group includes at least two main battery cells 1 connected in series; the multiple auxiliary battery cells 2 include at least one auxiliary battery cell group, and the auxiliary battery cell group includes at least two auxiliary battery cells 2 connected in series, and the main battery cell group and the auxiliary battery cell group are connected in parallel.

[0154] Specifically, the main battery cell group and the auxiliary battery cell group are electrically connected in parallel, so that the main battery cell group after series boost and the auxiliary battery cell group after series boost form a parallel power supply circuit, which can jointly output power to the outside, realize the current complementarity and capacity sharing between the groups, and form a complete battery pack power supply structure.

[0155] By connecting at least two main cells 1 in series to form a main cell group and at least two auxiliary cells 2 in series to form an auxiliary cell group, the overall output voltage of the module can be increased through series connection to meet the high-voltage power supply requirements of the battery device and adapt to the working conditions of the whole vehicle or high-power electrical load.

[0156] The main cell 1 and auxiliary cell 2 are each grouped and then connected in parallel. The main cell group and auxiliary cell group can be sampled, voltage equalization and thermal management and control can be performed independently. This is conducive to the consistent control of voltage and temperature of each group, reducing the voltage difference and temperature difference between cells and delaying the overall capacity decay.

[0157] Reference Figure 9 As an optional solution, the battery device also includes a first temperature sensor 71, a second temperature sensor 72, a regulation component 73, and a control component 74. The first temperature sensor 71 monitors the temperature of the main battery cell 1; the second temperature sensor 72 monitors the temperature of the auxiliary battery cell 2; and the regulation component 73 is used to regulate the heat exchange efficiency of the heat exchange medium in the second flow channel 41.

[0158] The control unit 74 is connected to the regulation component 73, the first temperature sensor 71 and the second temperature sensor 72. When the temperature monitored by the first temperature sensor 71 and the second temperature sensor 72 meets the set conditions, the control unit 74 sends a first signal to the regulation component 73. When the regulation component 73 receives the first signal, it regulates the heat exchange efficiency of the heat exchange medium in the second flow channel 41.

[0159] For example, the first temperature sensor 71 is fixedly attached to the outer wall surface of the main battery cell 1, located at the center of the bottom surface of the main battery cell 1. The detection end of the first temperature sensor 71 is in close contact with the outer wall of the main battery cell 1 to monitor the real-time temperature data of the main battery cell 1 during charging and discharging. The second temperature sensor 72 is correspondingly fixedly attached to the outer wall surface of the auxiliary battery cell 2, and its installation position is adapted to the first temperature sensor 71. The second temperature sensor 72 can synchronously collect the real-time body temperature of the auxiliary battery cell 2, enabling independent monitoring and zoned acquisition of the temperatures of the main battery cell 1 and the auxiliary battery cell 2.

[0160] The control component 73 is used to control the flow rate or temperature of the heat exchange medium inside the second flow channel 41, thereby realizing flexible control of the heat exchange efficiency of the heat exchange medium inside the second flow channel 41, and indirectly completing the adjustment of the heat exchange intensity of the auxiliary battery 2 to adapt to the heat dissipation or constant temperature requirements of the auxiliary battery 2 under different operating conditions.

[0161] The signal input terminals of the control unit 74 are connected to the first temperature sensor 71 and the second temperature sensor 72 respectively, and the signal output terminal is connected to the control component 73. The control unit 74 can be a main control module of the battery management system or an independently set microcontroller or PLC control module, and has the functions of data reception, logic judgment and instruction sending.

[0162] The temperatures monitored by the first temperature sensor 71 and the second temperature sensor 72 meet the set conditions, including but not limited to at least one of the following: the temperature difference monitored by the first temperature sensor 71 and the second temperature sensor 72 is greater than the set value; the temperature monitored by the second temperature sensor 72 is greater than the set value; the temperature change rate monitored by the second temperature sensor 72 is greater than the set value.

[0163] When the temperature detected by the first temperature sensor 71 and the second temperature sensor 72 meets the set conditions, the control component 74 sends a first signal to the regulation component 73. After receiving the first signal from the control component 74, the regulation component 73 immediately performs the corresponding regulation action to adjust the heat exchange efficiency of the heat exchange medium in the second flow channel 41. The regulation component 73 increases the flow rate of the heat exchange medium or decreases the temperature of the heat exchange medium to reduce the temperature difference between the main and auxiliary cells 2 and maintain the overall temperature control balance of the battery device.

[0164] Reference Figure 9 As an optional solution, the control component 73 includes at least one of a temperature regulator and a flow regulator, wherein the flow regulator is used to regulate the flow rate of the heat exchange medium in the heat exchange channel, and the temperature regulator is used to regulate the temperature of the heat exchange medium in the heat exchange channel.

[0165] Specifically, the flow regulating component includes a second throttle valve, which is connected to the second flow channel 41. The second throttle valve can be installed in the second liquid inlet pipe, and the flow rate of the second flow channel 41 is controlled by adjusting the opening degree of the second throttle valve. The flow regulating component also includes a second variable frequency pump, which pumps heat exchange medium into the second liquid inlet pipe. The flow rate of the heat exchange medium in the second flow channel 41 is controlled by adjusting the power of the second variable frequency pump.

[0166] The flow regulating component includes a first throttle valve, which is connected to a first flow channel 31. The first throttle valve can be installed in the first liquid inlet pipe, and the flow rate of the first flow channel 31 is controlled by adjusting the opening degree of the first throttle valve. The flow regulating component also includes a first variable frequency pump, which pumps heat exchange medium into the first liquid inlet pipe. The flow rate of the heat exchange medium in the first flow channel 31 is controlled by adjusting the power of the first variable frequency pump.

[0167] The temperature control components include a chiller unit, which regulates the temperature of the heat exchange medium flowing into the second inlet pipe. For example, it can lower the supply temperature of the heat exchange medium flowing into the second inlet pipe from 25°C to 18°C. The chiller unit can also regulate the temperature of the heat exchange medium flowing into the first inlet pipe.

[0168] The control component 73 is compatible with both flow and temperature regulators, allowing for control of heat exchange intensity based on the flow rate of the heat exchange medium and heat exchange capacity based on the temperature of the heat exchange medium itself. This dual-mode control adapts to the rapid heat dissipation requirements of the auxiliary battery. Through real-time switching of flow rate and dynamic fine-tuning of the heat exchange medium temperature, it can quickly respond to temperature fluctuations caused by changes in the cell's charging and discharging load.

[0169] Furthermore, a flexible thermal conductive layer is installed on the outer shell of the module composed of the main battery cell and the auxiliary battery cell. The thermal conductive layer adopts graphene-reinforced thermal conductive pads and is attached between the surface of the main battery cell 1 and the auxiliary battery cell 2 and the module shell. A detachable thermal bridge connection structure is set between multiple modules. According to the integration requirements of the battery pack or energy storage power station, the thermal conduction efficiency between modules can be flexibly adjusted to achieve temperature balance between modules.

[0170] The flexible thermal conductive layer can fit tightly against the surface of the battery cell, reducing the contact thermal resistance between the battery cell and the module housing, improving the heat transfer efficiency, and also has a buffering effect to reduce damage to the battery cell caused by collisions during transportation and installation, thus balancing temperature control and battery cell protection.

[0171] The detachable thermal bridge connection structure can flexibly adapt to different integration scales. When used in module-level applications, the thermal bridge can be removed to reduce thermal interference between modules. When used in battery pack or energy storage power station applications, the thermal bridge can be installed to realize heat conduction between modules, eliminate temperature deviations between modules, and improve the temperature consistency of the entire system.

[0172] Reference Figure 10 This application discloses a battery device including a plurality of battery cell units. Each battery cell unit includes a main battery cell 1, an auxiliary battery cell 2, a first heat exchanger 3, and a second heat exchanger 4. The main battery cell 1 and the auxiliary battery cell 2 are connected in parallel. The rated capacity of the main battery cell 1 is higher than that of the auxiliary battery cell 2, and the rated discharge rate of the auxiliary battery cell 2 is greater than that of the main battery cell 1. The first heat exchanger 3 is attached to the surface of the main battery cell 1, and the second heat exchanger 4 is attached to the surface of the auxiliary battery cell 2. The first heat exchanger 3 is provided with a first flow channel 31, and the second heat exchanger 4 is provided with a second flow channel 41. The second flow channel 41 is isolated from the first flow channel 31. Both the first flow channel 31 and the second flow channel 41 are provided with heat exchange medium, and at least one of the flow rate and temperature of the heat exchange medium can be independently adjusted.

[0173] The second heat exchanger 4 is attached to the large surface of the auxiliary battery cell 2, and the large surface of the auxiliary battery cell 2 is the surface of the auxiliary battery cell 2 with an area not less than the other surfaces. The second heat exchanger 4 also includes a second thermally conductive layer 42, which is attached to the surface of the auxiliary battery cell 2 and is located between the second flow channel 41 and the auxiliary battery cell 2. The main battery cell 1 and the auxiliary battery cell 2 are stacked, and the second thermally conductive layer 42 is located on the side of the auxiliary battery cell 2 away from the main battery cell 1. The first heat exchanger 3 also includes a first thermally conductive layer 32, which is attached to the surface of the main battery cell 1 and is located between the first flow channel 31 and the main battery cell 1. The first thermally conductive layer 32 is located on the side of the main battery cell 1 away from the auxiliary battery cell 2. The battery cell unit also includes a heat insulation component 5 and a unidirectional heat-conducting component 6, with the heat insulation component 5 located on the side of the main battery cell 1 away from the auxiliary battery cell 2. A unidirectional heat conduction element 6 is located between the main battery cell 1 and the auxiliary battery cell 2. The forward thermal conductivity of the unidirectional heat conduction element 6 is greater than its reverse thermal conductivity. The forward thermal conductivity is the thermal conductivity of the auxiliary battery cell 2 towards the main battery cell 1, and the reverse thermal conductivity is the thermal conductivity of the main battery cell 1 towards the auxiliary battery cell 2. The first heat exchange element 3 is located on the side of the main battery cell 1 away from the unidirectional heat conduction element 6, and the second heat exchange element 4 is located on the side of the auxiliary battery cell 2 away from the unidirectional heat conduction element 6.

[0174] The main battery cell 1 is a lithium iron phosphate battery cell or a ternary lithium battery cell; the auxiliary battery cell 2 is a lithium titanate battery cell. The battery cell unit also includes a first temperature sensor 71, a second temperature sensor 72, a control component 73, and a control unit 74. The first temperature sensor 71 monitors the temperature of the main battery cell 1; the second temperature sensor 72 monitors the temperature of the auxiliary battery cell 2; the control component 73 is used to control the heat exchange efficiency of the heat exchange medium in the second flow channel 41; the control unit 74 is signal-connected to the control component 73, the first temperature sensor 71, and the second temperature sensor 72. When the temperature monitored by the first temperature sensor 71 and the second temperature sensor 72 meets the set conditions, the control unit 74 sends a first signal to the control component 73; the control component 73, upon receiving the first signal, controls the heat exchange efficiency of the heat exchange medium in the second flow channel 41. The control component 73 includes at least one of a temperature regulator and a flow regulator. The flow regulator is used to control the flow rate of the heat exchange medium in the heat exchange channel, and the temperature regulator is used to control the temperature of the heat exchange medium in the heat exchange channel.

[0175] This case study focuses on a containerized energy storage power station used to provide primary frequency regulation services to the power grid. This operating condition requires the energy storage system to respond to grid commands within seconds, performing high-power charging and discharging, and then entering standby or low-power operation.

[0176] To balance energy density and power characteristics, this system uses lithium iron phosphate cells as the main cell 1 and lithium titanate cells as the auxiliary cell 2. Lithium iron phosphate cells have a large heat capacity and generate heat gradually, making them the energy unit; lithium titanate cells have extremely low internal resistance and high power density, but generate intense heat rapidly during the instantaneous process, making them the power unit.

[0177] The first heat exchanger 3 has a microchannel first flow channel 31 inside, and the first heat exchanger 3 is arranged close to the large surface of the main battery cell 1. The inlet of the first flow channel 31 is connected to the main control cooling circulation loop through an electric three-way proportional valve. This loop uses ethylene glycol aqueous solution, is driven by a variable frequency pump, and is connected to a fixed frequency chiller unit. The chiller unit has two independent liquid outlet branches, which are respectively connected to the first liquid inlet pipe and the second liquid inlet pipe. The chiller unit can provide heat exchange media with different temperatures and flow rates to the first liquid inlet pipe and the second liquid inlet pipe.

[0178] The second heat exchanger 4 has a second flow channel 41 with microchannels inside, and the second heat exchanger 4 is arranged close to the heat dissipation surface of the auxiliary battery cell 2. The inlet of the second flow channel 41 is connected to the auxiliary control cooling circulation loop through an independent electric regulating valve. This loop also uses ethylene glycol aqueous solution, but is driven by another variable frequency pump with a larger head and connected to the same chiller unit.

[0179] Temperature sensors are mounted on the surface of each main cell 1 and auxiliary cell 2, located at the non-tab end of each cell. All sensor signals are aggregated to the module-level battery management unit and then transmitted via CAN bus to the energy management system at the energy storage power station level.

[0180] Control logic and operation process: Normal standby state: The power grid frequency is stable, and the system has no power commands. The EMS controls both the main and auxiliary cooling circuits to operate at the base flow rate, which is 15% of the rated flow rate, maintaining the temperature of all cells within the set temperature range.

[0181] High-power pulse discharge state: The EMS receives a command requesting the system to generate power at maximum power. Auxiliary cell 2 instantly outputs a high-rate current, its internal resistance generates heat, and its body temperature rises sharply.

[0182] The distributed sensors detected that the temperature of auxiliary cell 2 was rising at a rate of 0.8℃ / second in real time. Meanwhile, the temperature of main cell 1 was rising at a rate of only 0.05℃ / second. When the temperature difference between main cell 1 and auxiliary cell 2 reached 4.5℃ and the temperature of auxiliary cell 2 itself exceeded 48℃, the EMS immediately activated the differentiated thermal management strategy.

[0183] Independent adjustment action: The EMS sends a command to the variable frequency pump in the auxiliary control loop and the electric valve of the second flow channel 41, increasing the coolant flow rate in the second flow channel 41 from the base value to the full rated flow rate within 0.5 seconds. Simultaneously, the chiller unit is instructed to temporarily reduce the supply temperature of the heat exchange medium in the second flow channel 41 from 25°C to 18°C. This is equivalent to applying high-intensity, rapid cooling to the auxiliary battery cell 2, forcibly removing a large amount of heat.

[0184] EMS maintains the flow rate of the first flow channel 31 at only 20% of the rated flow rate, while the supply temperature remains at 25°C. The main cell 1 is cooled only relatively gently to reduce energy waste and low-temperature stress caused by excessive cooling.

[0185] When the 30-second pulse ends, the peak temperature of auxiliary cell 2 is successfully controlled below 51℃. Without this structure, the peak temperature of auxiliary cell 2 would exceed 60℃, while the temperature of main cell 1 would only rise to 28℃.

[0186] The discharge command ends, and the system enters a 10-minute low-power standby. The EMS command gradually reduces the flow rate in the second flow channel 41 to 30%, while the flow rate in the main first flow channel 31 increases to 50%. The main battery cell 1 absorbs and slowly releases residual heat, while the heat stored in the main battery cell 1 is gradually carried away through the first flow channel 31. The entire system returns to the balanced set temperature range within 5 minutes.

[0187] Secondly, embodiments of this application also provide an energy storage device, including a battery device provided in any of the embodiments of the first aspect, the battery device being used to store or provide electrical energy.

[0188] In the above technical solution, the problem of large temperature difference between the main and auxiliary battery cells is improved by using a first heat exchanger to cool the main battery cell and a second heat exchanger to cool the auxiliary battery cell.

[0189] Thirdly, embodiments of this application also provide an electrical device, including a battery device provided in any of the embodiments of the first aspect, the battery device being used to store or provide electrical energy.

[0190] In the above technical solution, the problem of large temperature difference between the main and auxiliary battery cells is improved by using a first heat exchanger to cool the main battery cell and a second heat exchanger to cool the auxiliary battery cell.

[0191] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way.

[0193] This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery device, characterized in that, It includes several battery cell units, each of which includes a main battery cell, an auxiliary battery cell, a first heat exchanger, and a second heat exchanger. The main battery cell and the auxiliary battery cell are connected in parallel. The rated capacity of the main battery cell is higher than that of the auxiliary battery cell, and the rated discharge rate of the auxiliary battery cell is greater than that of the main battery cell. The first heat exchanger is attached to the surface of the main battery cell, and the second heat exchanger is attached to the surface of the auxiliary battery cell. The first heat exchanger is provided with a first flow channel, and the second heat exchanger is provided with a second flow channel. The second flow channel is isolated from the first flow channel. Both the first and second flow channels are provided with heat exchange medium, and at least one of the flow rate and temperature of the heat exchange medium can be independently adjusted.

2. The battery device according to claim 1, characterized in that, The second heat exchanger is attached to the large surface of the auxiliary battery core, and the large surface of the auxiliary battery core is the surface of the auxiliary battery core with an area not less than the other surfaces.

3. The battery device according to claim 1, characterized in that, The second heat exchanger also includes a second thermally conductive layer, which is attached to the surface of the auxiliary battery cell and is located between the second flow channel and the auxiliary battery cell.

4. The battery device according to claim 3, characterized in that, The main battery cell and the auxiliary battery cell are stacked together, and the second thermal conductive layer is located on the side of the auxiliary battery cell away from the main battery cell.

5. The battery device according to claim 1, characterized in that, The first heat exchanger further includes a first thermally conductive layer, which is attached to the surface of the main battery cell and is located between the first flow channel and the main battery cell.

6. The battery device according to claim 5, characterized in that, The main battery cell and the auxiliary battery cell are stacked together, and the first thermally conductive layer is located on the side of the main battery cell away from the auxiliary battery cell.

7. The battery device according to claim 1, characterized in that, The main battery cell and the auxiliary battery cell are stacked together; The cell unit also includes a heat insulation component, which is located on the side of the main cell away from the auxiliary cell.

8. The battery device according to any one of claims 1 to 7, characterized in that, The battery cell unit also includes a unidirectional heat conduction element, which is located between the main battery cell and the auxiliary battery cell. The forward heat conduction coefficient of the unidirectional heat conduction element is greater than the reverse heat conduction coefficient. The forward heat conduction coefficient is the thermal conductivity of the auxiliary battery cell towards the main battery cell, and the reverse heat conduction coefficient is the thermal conductivity of the main battery cell towards the auxiliary battery cell.

9. The battery device according to claim 8, characterized in that, The first heat exchanger is located on the side of the main battery cell away from the unidirectional heat conduction element, and the second heat exchanger is located on the side of the auxiliary battery cell away from the unidirectional heat conduction element.

10. The battery device according to claim 1, characterized in that, The main battery cell is a lithium iron phosphate battery cell; the auxiliary battery cell is a lithium titanate battery cell.

11. The battery device according to any one of claims 1 to 7, characterized in that, It also includes a first temperature sensor, a second temperature sensor, a control assembly, and a control component; wherein, The first temperature sensor monitors the temperature of the main battery cell; the second temperature sensor monitors the temperature of the auxiliary battery cell; and the control component is used to control the heat exchange efficiency of the heat exchange medium in the second flow channel. The control unit is signal-connected to the regulation component, the first temperature sensor and the second temperature sensor. When the control unit receives the temperature monitored by the first temperature sensor and the second temperature sensor and the temperature meets the set condition, it sends a first signal to the regulation component. When the control component receives the first signal, it adjusts the heat exchange efficiency of the heat exchange medium in the second flow channel.

12. The battery device according to claim 11, characterized in that, The control component includes at least one of a temperature regulator and a flow regulator. The flow regulator is used to control the flow rate of the heat exchange medium in the second flow channel, and the temperature regulator is used to control the temperature of the heat exchange medium in the second flow channel.

13. An electrical appliance, characterized in that, It includes a plurality of battery devices according to any one of claims 1 to 12, the battery devices being used to store or provide electrical energy.

14. An energy storage device, characterized in that, It includes a plurality of battery devices according to any one of claims 1 to 12, the battery devices being used to store or provide electrical energy.

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