Cell temperature detection device and battery pack

Abstract

This application relates to a cell temperature detection device and a battery pack. The cell temperature detection device includes: a thermally conductive structural adhesive, one side of which is bonded to the busbar of the cell; a flexible circuit board, bonded to the side of the thermally conductive structural adhesive opposite to the busbar; a temperature sensor mounted on the flexible circuit board; and a hot-pressing film assembly covering the busbar, the thermally conductive structural adhesive, and the flexible circuit board. In this application, the thermally conductive structural adhesive bonds the busbar to the flexible circuit board, replacing the existing nickel sheet welding method. This eliminates the need for welding, simplifies the production process, and reduces production complexity. Furthermore, the hot-pressing film assembly eliminates the need for additional fixing brackets, aluminum braces, or other structures, further simplifying the production process and reducing complexity. In addition, the thermally conductive structural adhesive directly transfers heat from the busbar to the temperature sensor on the flexible circuit board, which is a shorter path than the conduction through the nickel sheet in the prior art, reducing heat transfer delay and enabling rapid temperature detection.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cell temperature detection device and a battery pack. Background Technology

[0002] As an important component of the battery system, the cell contact system (CCS) undertakes key functions such as current conduction and signal acquisition between cells. The temperature sensor in the cell contact system can monitor the temperature of the cells inside the battery system in real time. The temperature data it collects is the core basis for the battery management system to judge the operating status of the cells and ensure the safety of the battery system.

[0003] In conventional technologies, temperature sensors achieve temperature conduction and integration using nickel strips. Specifically, one end of the nickel strip is soldered to the battery cell busbar, and the other end is soldered to a flexible printed circuit board (FPC). The temperature sensor is mounted on the FPC, and the nickel strip conducts the temperature from the battery cell busbar to the sensor. This approach relies on nickel strip soldering, leading to a complex manufacturing process. Furthermore, nickel strip conduction prolongs the temperature conduction path, causing a lag in temperature detection response, making it difficult to meet the current development requirements for efficient, economical, and lightweight battery systems. Utility Model Content

[0004] Therefore, it is necessary to provide a cell temperature detection device and battery pack to address the problem of complex production and installation processes for temperature sensors in conventional technologies.

[0005] This invention provides a battery cell temperature detection device, comprising: a thermally conductive structural adhesive, one side of which is bonded to a busbar of the battery cell; a flexible circuit board, which is bonded to the side of the thermally conductive structural adhesive opposite to the busbar; a temperature sensor mounted on the flexible circuit board; and a hot-pressing film assembly covering the busbar, the thermally conductive structural adhesive, and the flexible circuit board.

[0006] According to one embodiment of the present invention, it further includes: a reinforcing plate, the reinforcing plate being stacked on the side of the flexible circuit board opposite to the busbar and located inside the hot-pressing film assembly.

[0007] According to one embodiment of the present invention, it further includes: a reinforcing adhesive, one side of which is bonded to the flexible circuit board and the other side of which is bonded to the reinforcing plate.

[0008] According to one embodiment of the present invention, the reinforcing plate includes an epoxy resin plate or a metal plate.

[0009] According to one embodiment of the present invention, the reinforcing plate is provided with a through hole, and the temperature sensor passes through the through hole.

[0010] According to one embodiment of the present invention, it further includes: a loop frame, the loop frame being fixed to the side of the flexible circuit board away from the busbar, and the loop frame being located outside the temperature sensor.

[0011] According to one embodiment of the present invention, it further includes a protective layer that fills the inner side of the herringbone frame and covers the outer side of the temperature sensor.

[0012] According to one embodiment of the present invention, the loop frame is bonded and fixed to the reinforcing plate, and the loop frame passes through one side of the hot-pressing film assembly.

[0013] According to one embodiment of the present invention, the temperature sensor includes a negative temperature coefficient resistor.

[0014] The present invention also provides a battery pack, including: a battery cell; a busbar; and a battery cell temperature detection device according to the above embodiments.

[0015] The aforementioned cell temperature detection device and battery pack use thermally conductive structural adhesive to bond the busbar and flexible circuit board, replacing the existing nickel sheet welding method. This eliminates the need for welding, simplifies the production process, and reduces production complexity. Furthermore, the hot-pressed film assembly provides a secure seal, eliminating the need for additional fixing brackets, aluminum braces, or other structures, further simplifying the production process and reducing complexity. In addition, the thermally conductive structural adhesive directly transfers heat from the busbar to the temperature sensor on the flexible circuit board, which is a shorter path than the nickel sheet conduction used in existing technologies. This reduces heat transfer delay and enables rapid temperature detection. Attached Figure Description

[0016] Figure 1 This is a half-sectional view of a cell temperature detection device according to an embodiment of this application under an explosion state.

[0017] Figure label:

[0018] 10. Busbar; 20. Thermally conductive structural adhesive; 30. Flexible circuit board; 40. Temperature sensor; 50. Hot-pressed film assembly; 51. Upper film layer; 52. Lower film layer; 60. Reinforcing plate; 61. Through hole; 70. Reinforcing adhesive; 80. U-shaped frame. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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 therefore should not be construed as a limitation of this application.

[0021] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[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 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0025] Combination Figure 1 An embodiment of this application provides a battery cell temperature detection device, including a thermally conductive structural adhesive 20, a flexible circuit board 30, a temperature sensor 40, and a hot-pressing film assembly 50. One side of the thermally conductive structural adhesive 20 is bonded to the busbar 10 of the battery cell. The flexible circuit board 30 is bonded to the side of the thermally conductive structural adhesive 20 opposite to the busbar 10. The temperature sensor 40 is mounted on the flexible circuit board 30. The hot-pressing film assembly 50 covers the outside of the busbar 10, the thermally conductive structural adhesive 20, and the flexible circuit board 30.

[0026] In this embodiment, the thermally conductive structural adhesive 20 can be a thermally conductive double-sided adhesive. One side of the thermally conductive structural adhesive 20 is bonded to the busbar 10 of the battery cell. Through the bonding action, the thermally conductive structural adhesive 20 and the busbar 10 form a stable fixed fit, ensuring that subsequent heat can be effectively transferred from the busbar 10 to the thermally conductive structural adhesive 20.

[0027] The flexible circuit board 30 is disposed on the side of the thermally conductive structural adhesive 20 away from the busbar 10. The flexible circuit board 30 is bonded to the thermally conductive structural adhesive 20. Through the bonding, the flexible circuit board 30 forms an indirect fixed relationship with the busbar 10 with the help of the thermally conductive structural adhesive 20. At the same time, the flexible circuit board 30 provides a stable mounting carrier for the temperature sensor 40.

[0028] Temperature sensor 40 is mounted on flexible circuit board 30. Through its mounting and cooperation with flexible circuit board 30, temperature sensor 40 can directly receive the heat transferred from thermally conductive structural adhesive 20 to flexible circuit board 30, thereby realizing real-time detection of cell temperature.

[0029] The hot-pressing film assembly 50 completely covers the outside of the busbar 10, the thermally conductive structural adhesive 20, and the flexible circuit board 30. Through the covering effect, it forms an overall fixed constraint on the above three components, and at the same time protects each component, avoiding the influence of external environmental factors on the connection stability between the components, and ensuring that the entire device remains structurally reliable during use.

[0030] In this embodiment, the busbar 10 and the flexible circuit board 30 are bonded together using thermally conductive structural adhesive 20, eliminating the need for traditional nickel sheet welding. This process avoids the welding steps between the nickel sheet and the busbar 10, and between the nickel sheet and the flexible circuit board 30, reducing the number of steps in the production process and lowering its complexity. At the same time, it avoids the risk of unreliable connection due to unstable welding quality, thus improving the stability of the production process and the product qualification rate.

[0031] Furthermore, the thermally conductive structural adhesive 20 directly connects the busbar 10 and the flexible circuit board 30. The heat generated by the battery cell during operation is directly transferred to the thermally conductive structural adhesive 20 through the busbar 10, and then transferred from the thermally conductive structural adhesive 20 to the temperature sensor 40 on the flexible circuit board 30. This eliminates the need for the nickel sheet as an intermediate conductive medium, significantly shortening the path of heat transfer from the busbar 10 to the temperature sensor 40. This reduces heat loss and delay during the transfer process, enabling the temperature sensor 40 to detect temperature changes in the battery cell more quickly. This significantly improves the response speed of temperature detection, providing strong support for the battery management system to obtain battery cell temperature information in a timely manner and activate corresponding protection mechanisms, thereby enhancing the operational safety of the battery system.

[0032] Furthermore, by covering the busbar 10, thermally conductive structural adhesive 20, and flexible circuit board 30 with a hot-press film assembly 50, the overall fixation of each component can be achieved through the covering effect of the hot-press film assembly 50, without the need for additional special fixing brackets or processing of fixing features on other components. This reduces the number of parts required for the device, lowers the procurement and processing costs of parts, and avoids the weight increase caused by additional fixing structures. It helps to control the overall weight of the battery pack, meets the current development needs of lightweight battery systems, and improves the adaptability of the battery system in application scenarios.

[0033] In some embodiments, a reinforcing plate 60 is also included, which is stacked on the side of the flexible circuit board 30 away from the busbar 10 and located inside the hot-pressing film assembly 50.

[0034] The reinforcing plate 60 is stacked on the flexible circuit board 30 on the side away from the busbar 10. Its overall position is within the internal space of the hot-press film assembly 50, not exceeding the coverage area of ​​the hot-press film assembly 50. The reinforcing plate 60 and the surface of the flexible circuit board 30 are fully bonded, with no obvious gap between them. Simultaneously, the outer wall of the reinforcing plate 60 contacts and engages with the inner wall of the hot-press film assembly 50. Optionally, the overall contour of the reinforcing plate 60 is adapted to the contour of the corresponding area of ​​the flexible circuit board 30, ensuring that the reinforcing plate 60 can fully cover the corresponding area of ​​the flexible circuit board 30.

[0035] The reinforcing plate 60 significantly enhances the structural strength of the flexible circuit board 30, preventing the flexible circuit board 30 from bending or deforming during the hot pressing process or long-term use due to its soft material. This ensures that the temperature sensor 40 installed on the flexible circuit board 30 is always in a stable position, preventing the temperature sensor 40 from shifting due to deformation of the flexible circuit board 30 and affecting the accuracy of temperature detection.

[0036] Meanwhile, the reinforcing plate 60 is located inside the hot-press film assembly 50, and can be protected by the covering effect of the hot-press film assembly 50, avoiding direct impact from factors such as dust and moisture in the external environment, extending the service life of the reinforcing plate 60, and without changing the fixing effect of the hot-press film assembly 50 on core components such as the busbar 10 and the flexible circuit board 30.

[0037] In some embodiments, the cell temperature detection device further includes a reinforcing adhesive 70, one side of which is bonded to the flexible circuit board 30 and the other side is bonded to the reinforcing plate 60.

[0038] The reinforcing adhesive 70 is a double-sided adhesive located between the flexible circuit board 30 and the reinforcing plate 60, forming a connection medium between the two. One side is bonded to the surface of the flexible circuit board 30 facing away from the busbar 10, ensuring no gaps remain between this side and the flexible circuit board 30; the other side is bonded to the surface of the reinforcing plate 60 facing the flexible circuit board 30, so that the reinforcing plate 60 and the flexible circuit board 30 form a tight connection through the reinforcing adhesive 70. The position of this connection remains inside the hot-press film assembly 50, not exceeding the coverage area of ​​the hot-press film assembly 50, and the distribution range of the reinforcing adhesive 70 matches the coverage area of ​​the reinforcing plate 60, not exceeding the boundary of the reinforcing plate 60.

[0039] The reinforcing adhesive 70 ensures a reliable bond between the flexible circuit board 30 and the reinforcing plate 60, effectively preventing relative displacement between them. This further enhances the structural support provided by the reinforcing plate 60 to the flexible circuit board 30, ensuring that the flexible circuit board 30 remains flat throughout long-term use and providing a stable mounting base for the temperature sensor 40. Furthermore, the adhesive 70 eliminates the need for additional bolts, clips, or other mechanical fastening structures, simplifying the assembly process, reducing assembly steps, and without increasing the overall structural complexity or weight, thus meeting the lightweight development requirements of battery systems.

[0040] In addition, the reinforcing adhesive 70 can fill the tiny gaps that may exist between the flexible circuit board 30 and the reinforcing plate 60, further improving the sealing of the connection between the two and preventing impurities from entering the gaps and affecting the performance of the components.

[0041] In some embodiments, the reinforcing plate 60 includes an epoxy resin plate or a metal plate. The epoxy resin plate possesses insulating properties and has a flat overall structure, allowing for a stable connection with the flexible circuit board 30 via reinforcing adhesive 70 in a laminated manner. The metal plate possesses good structural strength and can also be laminated with the flexible circuit board 30. Both types of reinforcing plates 60 can fit into the installation space inside the hot-press film assembly 50. Their thickness and contour can be adjusted according to the size of the flexible circuit board 30 and installation requirements, ensuring a tight connection with the reinforcing adhesive 70 or the flexible circuit board 30, meeting the requirements of the overall assembly structure.

[0042] When the epoxy resin board is used as the reinforcing plate 60, its insulation properties effectively prevent the risk of electrical connection between the reinforcing plate 60 and other conductive components such as the busbar 10 and the circuit on the flexible circuit board 30 in the battery cell temperature detection device, ensuring the electrical safety of the entire device. This is suitable for applications with high insulation performance requirements. When the metal plate is used as the reinforcing plate 60, its better structural strength provides stronger support for the flexible circuit board 30, effectively resisting deformation under external forces. This is suitable for environments that may be subject to minor impacts or vibrations. The choice of the two materials can be flexibly adjusted according to different application requirements, ensuring that the reinforcing plate 60 can effectively reinforce the flexible circuit board 30 while improving the adaptability of the device in different usage environments. At the same time, neither material will adversely affect the heat conduction path from the flexible circuit board 30 to the temperature sensor 40, and will not interfere with the accuracy and response speed of temperature detection.

[0043] Of course, the reinforcing plate 60 can also be made of other materials as needed, which will not be listed here.

[0044] In some embodiments, the reinforcing plate 60 is provided with a through hole 61, through which the temperature sensor 40 passes.

[0045] The position of the through hole 61 corresponds perfectly to the mounting position of the temperature sensor 40 on the flexible circuit board 30, ensuring accurate insertion of the temperature sensor 40. The temperature sensor 40 enters through the through hole 61 from the side facing the flexible circuit board 30 and exits from the side facing away from the flexible circuit board 30, ensuring that the main body of the temperature sensor 40 is completely within the internal space of the through hole 61. Its pins, which connect to the flexible circuit board 30, remain fixed to the flexible circuit board 30 and do not loosen during insertion. The diameter of the through hole 61 matches the external dimensions of the temperature sensor 40, ensuring no significant movement of the temperature sensor 40 within the through hole 61 after insertion, and that the inner wall of the through hole 61 remains adjacent to the outer wall of the temperature sensor 40, preventing compression.

[0046] The through hole 61 provides precise positioning and limiting for the temperature sensor 40, effectively preventing lateral displacement during assembly or use. This further ensures the installation accuracy of the temperature sensor 40, guaranteeing its alignment with the heat-conducting area on the flexible circuit board 30. This allows for accurate reception of heat transferred from the flexible circuit board 30, preventing temperature measurement data deviations due to positional misalignment. Simultaneously, the through hole 61 prevents the reinforcing plate 60 from obstructing or compressing the temperature sensor 40, avoiding direct contact between the reinforcing plate 60 and the temperature sensor 40 and affecting its normal operating performance.

[0047] In some embodiments, the cell temperature detection device further includes a U-shaped frame 80, which is fixed to the flexible circuit board 30 on the side away from the busbar 10 and is located outside the temperature sensor 40.

[0048] Optionally, the U-shaped frame 80 is an FR4 (Flame Retardant Type 4, flame-retardant glass fiber reinforced epoxy resin substrate) frame or an epoxy resin frame.

[0049] The U-shaped frame 80 is fixedly mounted on the flexible circuit board 30 on the side away from the busbar 10. Its overall structure is a closed frame, surrounding the temperature sensor 40 so that the temperature sensor 40 is completely within the internal area enclosed by the U-shaped frame 80 and does not exceed the boundary of the frame structure. The bottom of the U-shaped frame 80 is fully fitted and fixed to the surface of the flexible circuit board 30 without any gaps. The U-shaped frame 80 corresponds to the position of the through hole 61 and does not structurally interfere with the reinforcing plate 60.

[0050] The U-shaped frame 80 surrounds the temperature sensor 40, providing circumferential physical protection. This effectively prevents damage from minor impacts, friction, or foreign object contact, protecting the sensor's structural integrity and operational performance. Simultaneously, the frame structure defines the surrounding space of the temperature sensor 40, preventing other components within the device from shifting towards and interfering with it during assembly or use. This ensures the temperature sensor 40 remains in a stable operating environment, thereby guaranteeing the accuracy of temperature detection data. Furthermore, the U-shaped frame 80 is easy to fix, requiring no additional complex connectors, does not increase the overall assembly difficulty or structural weight, and can cooperate with other components to improve the overall structural stability.

[0051] In some embodiments, the cell temperature detection device further includes a protective layer (not shown) that fills the inside of the loop frame 80 and covers the outside of the temperature sensor 40.

[0052] The protective layer can be made of UA (Urea-formaldehyde Resin Adhesive). The protective layer completely fills the inner space enclosed by the U-shaped frame 80, leaving no gaps, and tightly wraps around the outer surface of the temperature sensor 40, ensuring complete adhesion between the outer wall of the temperature sensor 40 and the protective layer, leaving no area untouched. The filling range of the protective layer is strictly controlled within the boundary of the U-shaped frame 80, not exceeding its outer edge, and its top height does not exceed the height of the U-shaped frame 80, ensuring that the protective layer does not affect the covering effect of the hot-press film assembly 50. The protective layer forms a tight connection with the surface of the flexible circuit board 30 and the inner wall of the U-shaped frame 80, forming a complete protective space that completely encloses the temperature sensor 40.

[0053] The protective layer fills the inside of the U-shaped frame 80 and wraps around the temperature sensor 40, providing comprehensive sealing and protection for the temperature sensor 40. It effectively isolates the sensor from dust, moisture, oil, and other impurities in the external environment, preventing these contaminants from entering the connection between the temperature sensor 40 and the flexible circuit board 30. This avoids electrical performance degradation or short-circuit failures caused by impurity accumulation, ensuring stable operation of the temperature sensor 40. Simultaneously, the protective layer has a certain buffering capacity, absorbing external vibration or impact energy, reducing the impact of vibration and impact on the temperature sensor 40, preventing positional displacement or structural damage due to vibration, and extending the service life of the temperature sensor 40. Furthermore, the material of the protective layer does not impede heat transfer and will not adversely affect the heat conduction process from the flexible circuit board 30 to the temperature sensor 40, ensuring that the temperature detection response speed is not affected.

[0054] In some embodiments, the herringbone frame 80 is bonded and fixed to the reinforcing plate 60, and the herringbone frame 80 passes through one side of the hot-pressing film assembly 50.

[0055] The U-shaped frame 80 is fixedly connected to the reinforcing plate 60 by adhesive bonding. The bonding area is the outer wall of the U-shaped frame 80 and the surface of the reinforcing plate 60. After connection, the two remain tightly fitted without any relative gaps, forming a stable integrated structure. The adhesive bonding of the U-shaped frame 80 and the reinforcing plate 60 integrates the U-shaped frame 80, the reinforcing plate 60, and the flexible circuit board 30 into a more robust overall structure, further improving the reliability of the connections between components and preventing separation or loosening of components during assembly, transportation, or use, thus ensuring the stability of the overall structure. Furthermore, the adhesive bonding method eliminates the need for additional screws, rivets, or other fasteners, does not increase the weight or complexity of the overall structure, meets lightweight design requirements, and simplifies assembly steps, reducing assembly costs.

[0056] A portion of the structure of the U-shaped frame 80 passes through one side of the hot-press film assembly 50. Specifically, the hot-press film assembly 50 has a channel at a position corresponding to the U-shaped frame 80, adapting to its contour, allowing the U-shaped frame 80 to partially extend beyond the outside of the hot-press film assembly 50. The length of the extended portion does not affect the covering and fixing of other components by the hot-press film assembly 50. Optionally, the portion of the U-shaped frame 80 that connects to the flexible circuit board 30 and the reinforcing plate 60 is located inside the hot-press film assembly 50, ensuring adequate protection for the core connection points.

[0057] The U-shaped frame 80 is inserted on one side of the hot-press film assembly 50, which can prevent the protruding structure of the U-shaped frame 80 from damaging the protective effect of the hot-press film assembly 50 on the core components such as the busbar 10, flexible circuit board 30, and reinforcing plate 60.

[0058] In some embodiments, the cell temperature detection device further includes an elastic support sheet, which can be a heat-resistant elastic metal sheet. The elastic support sheet is located inside the U-shaped frame 80, and multiple legs are provided around the elastic support sheet. The elastic support sheet abuts against the inner wall of the U-shaped frame 80 through the legs. One side of the elastic support sheet abuts against the temperature sensor 40. The elastic support sheet is covered by a protective layer.

[0059] After the U-shaped frame 80 is bonded and fixed to the reinforcing plate 60 with double-sided adhesive, and before the protective layer is applied to the inside of the U-shaped frame 80, the elastic support piece is placed inside the U-shaped frame 80, so that its plane is in contact with the upper surface of the temperature sensor 40, and the support foot is in slight contact with the inner wall of the U-shaped frame 80. Then, UA adhesive is applied according to the original plan. The UA adhesive will fill the gap between the elastic support piece and the U-shaped frame 80, fixing the support piece together with the temperature sensor 40 and the U-shaped frame 80.

[0060] The elastic support sheet can reduce the difficulty of dispensing adhesive, ensure the relative position stability of the U-shaped frame 80 and the temperature sensor 40, and absorb vibration energy through its own micro-elasticity to protect the temperature sensor 40 and buffer the direct force of external impact on the temperature sensor 40. At the same time, the support sheet and the protective layer together form a dual fixing structure of rigid fixation and flexible buffering, which prevents the temperature sensor 40 from being displaced or damaged due to long-term vibration, and significantly improves the long-term working reliability of the temperature sensor 40.

[0061] In some embodiments, the temperature sensor 40 includes a negative temperature coefficient resistor. As the temperature sensor 40, the negative temperature coefficient resistor exhibits a stable negative correlation with temperature changes, accurately reflecting subtle changes in the cell temperature. This provides the battery management system with accurate and reliable temperature detection data, enabling the system to promptly determine the cell's operating status based on the temperature data and quickly activate overheat protection, power limiting, and other measures when temperatures are abnormal, ensuring the safe operation of the battery system.

[0062] Meanwhile, the negative temperature coefficient resistor has a simple structure and small size, and is well compatible with the surface mount of the flexible circuit board 30. It can be stably fixed on the flexible circuit board 30 and is less prone to installation failures or loose connections due to complex structure.

[0063] In addition, the negative temperature coefficient resistor has a high sensitivity to temperature response, which can be fully combined with the advantage of thermally conductive structural adhesive 20 to shorten the heat conduction path, further improving the response speed of temperature detection, ensuring that fluctuations in cell temperature can be quickly identified, and avoiding safety hazards caused by response delay.

[0064] This utility model also provides a battery pack, including a battery cell, a busbar 10, and a battery cell temperature detection device according to the above embodiments.

[0065] For example, the battery cells, as the core energy storage components of the battery pack, are arranged inside the battery pack in a preset manner to form a battery cell group, with the electrode terminals of each battery cell facing the busbar 10. The busbar 10 is connected to the electrode terminals of each battery cell to realize current conduction between adjacent battery cells, so that multiple battery cells form a series or parallel energy output circuit through the busbar 10. The surface of the busbar 10 is kept flat to provide a suitable connection surface for the installation of the battery cell temperature detection device.

[0066] In this embodiment, the battery pack cell temperature detection device does not require traditional nickel sheet welding technology, nor does it require additional sensor mounting brackets or aluminum bars. This reduces welding processes and assembly steps for additional components during battery pack production, simplifying the overall production process, reducing operational difficulty, and preventing production failures caused by unstable welding quality or assembly deviations of additional components, thus improving the battery pack's production yield. The thermally conductive adhesive 20 in the cell temperature detection device directly transfers heat from the cells on the busbar 10 to the temperature sensor 40, shortening the heat conduction path. This allows the temperature sensor 40 to quickly capture cell temperature changes and transmit the temperature data to the battery pack's battery management system. When an abnormal cell temperature occurs, the battery management system can promptly activate overheat protection and power limiting measures, avoiding safety hazards caused by delayed temperature detection and significantly improving the battery pack's operational safety.

[0067] In some embodiments, the hot-press film includes an upper film layer 51 and a lower film layer 52. The lower film layer 52 is adhered to the side of the busbar 10 facing away from the flexible circuit board 30, forming a tight contact with the busbar 10. The edge of the lower film layer 52 extends beyond the width of the edge of the busbar 10, leaving a suitable overlap space with the edge of the upper film layer 51, so as not to interfere with the busbar 10 or the thermally conductive structural adhesive 20, ensuring that the thermally conductive structural adhesive 20 can properly bond the busbar 10 and the flexible circuit board 30. The edge of the upper film layer 51 and the edge of the lower film layer 52 extending beyond the edge of the busbar 10 are aligned, and the two are bonded together by a hot-pressing process to form a closed encapsulation space. The separate design of the upper film layer 51 and the lower film layer 52 can be adapted and bonded to the surface morphology of different components. After the edges of the two layers are bonded by hot pressing, the internal components can be precisely pressed and fixed, reducing structural loosening caused by bonding gaps, ensuring the stable position of the temperature sensor 40, and not affecting the accuracy of temperature detection. In addition, it can more comprehensively cover the exposed surfaces of each component, improve the anti-contamination capability of the entire cell temperature detection device, adapt to the complex usage environment inside the battery pack, and extend the service life of the components.

[0068] In some other embodiments, the battery pack may also include other components such as a housing, wires, or connectors, which will not be described in detail here.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell temperature detection device, characterized in that, include: A thermally conductive structural adhesive, one side of which is bonded to the busbar of the battery cell; A flexible circuit board is bonded to the side of the thermally conductive structural adhesive opposite to the busbar; A temperature sensor is mounted on the flexible circuit board; as well as A hot-pressed film assembly is applied to the outside of the busbar, the thermally conductive structural adhesive, and the flexible circuit board.

2. The cell temperature detection device according to claim 1, characterized in that, Also includes: A reinforcing plate is stacked on the side of the flexible circuit board away from the busbar and located inside the hot-pressing film assembly.

3. The cell temperature detection device according to claim 2, characterized in that, Also includes: A reinforcing adhesive is used, with one side of the adhesive bonded to the flexible circuit board and the other side bonded to the reinforcing plate.

4. The cell temperature detection device according to claim 2, characterized in that, The reinforcing plate may be an epoxy resin plate or a metal plate.

5. The cell temperature detection device according to claim 2, characterized in that, The reinforcing plate is provided with a through hole, and the temperature sensor passes through the through hole.

6. The cell temperature detection device according to any one of claims 2 to 5, characterized in that, Also includes: A U-shaped frame is fixed to the flexible circuit board on the side opposite to the busbar, and the U-shaped frame is located outside the temperature sensor.

7. The cell temperature detection device according to claim 6, characterized in that, Also includes: A protective layer is provided, which fills the inside of the herringbone frame and covers the outside of the temperature sensor.

8. The cell temperature detection device according to claim 6, characterized in that, The spiral frame is bonded and fixed to the reinforcing plate, and the spiral frame passes through one side of the hot-pressing film assembly.

9. The cell temperature detection device according to claim 1, characterized in that, The temperature sensor includes a negative temperature coefficient resistor.

10. A battery pack, characterized in that, include: Battery cell; Busbar; as well as The cell temperature detection device as described in any one of claims 1 to 9.

Images