A square case lithium battery

Abstract

The embodiment of the application discloses a square shell lithium battery, which comprises a shell, at least one battery cell and at least one measuring module arranged in the shell; at least one measuring module comprises a substrate and a flexible sensor arranged on the substrate, the substrate is matched with a large surface of at least one battery cell, and the flexible sensor is attached to the large surface of at least one battery cell. According to the application, the measuring module with the flexible sensor is directly attached to the large surface of the battery cell, which breaks through the limitation and lag problem of traditional external monitoring, realizes in-situ and real-time monitoring of the internal physical state of the lithium battery, improves the monitoring response time and measurement accuracy, and fundamentally improves the safety and reliability of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a prismatic lithium battery. Background Technology

[0002] With the rapid development of electric vehicles, energy storage systems, and portable electronic devices, the safety and reliability of lithium batteries, as core energy storage components, have become a focus of industry attention. Prismatic lithium batteries, due to their high energy density, good mechanical strength, and high packing efficiency, are widely used in high-power and high-energy-demand scenarios such as electric vehicles and grid energy storage. However, existing prismatic lithium battery designs suffer from a key technical bottleneck: the lack of a built-in sensor system, making it impossible to monitor the battery's internal physical state parameters (such as temperature and pressure) in real time and accurately. This deficiency makes the battery prone to thermal runaway, expansion, and even explosion under extreme conditions (such as overcharging, over-discharging, high temperature, or mechanical compression), seriously threatening user safety and equipment stability.

[0003] Currently, the safety management of lithium batteries mainly relies on the battery management system (BMS), but its monitoring methods have significant limitations: 1. Delayed Temperature Monitoring: Traditional BMS relies on temperature sensors installed on the outside of the battery cell (such as copper busbars, aluminum busbars, or the surface of the casing), which cannot directly sense the core temperature inside the battery cell. Due to the delay in heat conduction inside lithium batteries, when a local thermal anomaly occurs in the battery cell (such as an internal short circuit), the response of external sensors is severely delayed, which may lead to thermal runaway not being detected in time.

[0004] 2. Lack of Pressure Monitoring: During the charging and discharging process of lithium batteries, volume changes in electrode materials (such as the expansion of silicon anodes) and gas production from side reactions can cause internal pressure fluctuations, which in turn affect battery life and performance. However, current technologies lack effective built-in pressure monitoring methods, making it impossible to obtain real-time information on the internal mechanical state of the cell, thus making it difficult to detect problems such as battery expansion and lithium plating in a timely manner.

[0005] 3. Limited data dimensions: Traditional BMS relies on limited parameters such as voltage, current and external temperature for safety judgment, but the multi-physics coupling state inside the cell (such as temperature-pressure-strain coordinated changes) cannot be fully captured, resulting in insufficient accuracy of safety strategies.

[0006] Therefore, developing a technical solution that can directly integrate high-precision, miniaturized sensors inside prismatic lithium batteries to achieve real-time monitoring of parameters such as temperature and pressure in their core areas is of great significance for improving the safety management level and life prediction capability of lithium batteries. Utility Model Content

[0007] To address the problems of the prior art, this application provides a prismatic lithium battery to solve one or more technical problems existing in the prior art.

[0008] This application provides a prismatic lithium battery, the lithium battery including a housing and at least one cell and at least one measuring module disposed inside the housing; At least one of the measurement modules includes a substrate and a flexible sensor disposed on the substrate, the substrate being adapted to the large surface of at least one of the battery cells, and the flexible sensor being attached to the large surface of at least one battery cell.

[0009] In this embodiment, the design of a measurement module with a flexible sensor directly attached to the large surface of the battery cell overcomes the limitations and lag issues of traditional external monitoring, enabling in-situ, real-time monitoring of the internal physical state of the lithium battery. This improves the monitoring response time and measurement accuracy, fundamentally enhancing the safety and reliability of the battery.

[0010] Furthermore, in this application, at least one of the battery cells is in the form of a wound core structure or a stacked structure; At least one of the measurement modules is disposed in the central region of the core structure or the laminated structure; or, the number of the cells includes at least two, and each of the measurement modules is disposed between two adjacent core structures or two adjacent laminated structures.

[0011] In this embodiment of the application, by placing the measurement module in the core area of ​​the cell structure or between the cells, in-situ monitoring of the physical state of key parts inside the battery is achieved.

[0012] Furthermore, in this application, the flexible sensor includes a thin-film pressure sensor, which is attached to the surface of the substrate facing the large surface and is flatly attached to the large surface.

[0013] In this embodiment, by employing a thin-film pressure sensor and achieving a flat fit with the large surface of the battery cell, high-precision, in-situ measurement of internal pressure is achieved, ensuring the stability and reliability of pressure measurement and achieving ultimate compatibility with the internal space of the battery.

[0014] Furthermore, in this application, the flexible sensor also includes a temperature sensor, and a mounting groove is formed on the surface of the substrate facing the large surface. The temperature sensor is fixedly disposed in the mounting groove, and the thin-film pressure sensor is attached to the surface of the substrate facing the large surface where the mounting groove is not formed.

[0015] In this embodiment, temperature and pressure sensors are integrated using a composite structure on the substrate where mounting grooves and planes are bonded together. This achieves precise decoupling and independent measurement of temperature and pressure signals, improves sensor integration stability and space utilization efficiency, and enhances the comprehensiveness and synergy of internal condition monitoring.

[0016] Furthermore, in this application, at least one of the measurement modules further includes an adhesive, the thin-film pressure sensor is fixed to the substrate by the adhesive, and the temperature sensor is fixed in the mounting groove by the adhesive.

[0017] In this embodiment, by introducing an adhesive as a fixing material, the long-term reliability and stability of the measurement module under harsh conditions inside the battery are significantly improved, achieving stable adhesion and long-term reliability of the sensor.

[0018] Furthermore, in this application, the mounting groove is located on the surface of the substrate facing the large surface, the mounting groove extends along the X direction or Z direction on the surface, and a plurality of sampling points are arranged at intervals in the mounting groove, each sampling point being fixedly provided with at least one temperature sensor; the X direction is the length direction of the substrate, and the Z direction is the height direction of the substrate.

[0019] In this embodiment, by designing an extended mounting groove in a specific direction on the substrate surface and arranging multiple temperature acquisition points at intervals, high-precision, multi-dimensional monitoring of the internal temperature field distribution of the battery is achieved.

[0020] Furthermore, in this application, the mounting groove includes one, which is disposed at the center of the surface and the length direction of the mounting groove extends along the X or Z direction on the surface.

[0021] In this embodiment, by setting a single mounting groove at the center of the substrate surface and extending it along the X or Z direction, the most representative temperature information is captured with the simplest structure.

[0022] Furthermore, in this application, the mounting groove includes at least two, the at least two mounting grooves are arranged at intervals along the X direction on the surface and the length direction of the at least two mounting grooves extends along the Z direction on the surface; Alternatively, at least two of the mounting slots are arranged at intervals along the Z direction on the surface and the length direction of at least two of the mounting slots extends along the X direction on the surface.

[0023] In this embodiment, a miniaturized internal temperature sensing network is constructed by adopting a dual-axis distributed multiple mounting slot design, thereby achieving a leapfrog improvement in the monitoring capability of the temperature field of the large surface of the battery cell from line to surface.

[0024] Furthermore, in this application, the prismatic lithium battery also includes a data connection line, one end of which is communicatively connected to the flexible sensor, and the other end extends through the housing to the outside of the housing. The data connection line is a flexible printed circuit board.

[0025] In this embodiment, by using a flexible printed circuit board (FPC) as a data connection line, highly reliable extraction and system integration of sensor signals are achieved.

[0026] Furthermore, in this application, the housing includes a main body and a cover, the main body forming a receiving space for accommodating the battery cell and the measuring module, and the cover being disposed at the opening of the main body to close the receiving space; The data connection cable passes through a through hole in the cover and extends to the outside of the receiving space. The gap between the data connection cable and the through hole is provided with a sealing structure.

[0027] In this embodiment, by optimizing the specific lead-out path of the data connection line on the housing cover and setting a sealing structure, reliable signal transmission is ensured while fundamentally guaranteeing the sealing safety and long-term reliability of the battery.

[0028] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0029] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Furthermore, similar numbers in the drawings are used to denote similar components, wherein: Figure 1 This is an exploded view of a prismatic lithium battery provided in some embodiments of this application; Figure 2 This is an exploded view of a prismatic lithium battery from another perspective, provided in some embodiments of this application; Figure 3 This is a schematic diagram of the structure of the measurement module provided in some embodiments of this application; Figure 4 This is a partial exploded view of the measurement module provided in some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a substrate provided in some embodiments of this application; Figure 6 These are schematic diagrams of the substrate structure provided in other embodiments of this application; Figure 7 This is a schematic diagram of the structure of a substrate provided in some embodiments of this application; Figure 8 This is an exploded view of a prismatic lithium battery from one perspective, provided in some other embodiments of this application. Detailed Implementation

[0030] Some embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] As described in the background section, current safety management of lithium batteries mainly relies on the Battery Management System (BMS), but its monitoring methods have significant limitations, such as lag in temperature monitoring, lack of pressure monitoring, and limited data dimensions. To address these issues, this application proposes a novel prismatic lithium battery. By directly attaching a measurement module with flexible sensors to the large surface of the battery cell, it overcomes the limitations and lag issues of traditional external monitoring, achieving in-situ, real-time monitoring of the internal physical state of the lithium battery. This improves monitoring response time and measurement accuracy, fundamentally enhancing the battery's safety and reliability.

[0032] The solution of this application will now be described in detail with reference to the accompanying drawings and various embodiments.

[0033] Example 1 This application relates to a prismatic lithium battery, the core improvement of which lies in the integration of a dedicated measurement module inside the battery to achieve direct monitoring of the internal state of the cell. (Refer to...) Figure 1 and Figure 2 As shown, the prismatic lithium battery includes a casing 100, at least one battery cell 200, and at least one measurement module 300, both of which are built into the casing 100. The core components of the measurement module 300 include a substrate 310 and a flexible sensor 320 mounted thereon. The substrate 310 is designed to be adapted in shape and size to the large surface 210 of the battery cell 200, ensuring that the entire measurement module 300 can be stably attached to or fixed to the surface of the battery cell. Most importantly, the flexible sensor 320 is directly disposed on the substrate 310 and ultimately physically adheres to the large surface 210 of the battery cell 200, thereby establishing a measurement channel for directly sensing the internal physical state of the battery cell (such as temperature and pressure).

[0034] It should be noted that, in this embodiment, the large surface 210 of the battery cell 200 refers to the surface with the largest area of ​​the battery cell 200. The winding or stacked structure inside the battery cell 200 unfolds in the direction of its large surface, and the main heat generation and volume changes also occur in this area. By directly attaching the measurement module 300, which integrates the flexible sensor 320, to the large surface 210 of the battery cell 200 to provide the largest contact area, the flexible sensor 320 can collect a more representative and average signal, rather than a local and accidental data. This can overcome the limitations of traditional external monitoring and directly obtain the physical parameters (such as temperature and pressure) of the core area inside the battery cell. This fundamentally solves the problem of delayed external temperature monitoring caused by heat conduction delay and provides early and accurate early warning capabilities for safety hazards such as thermal runaway. Furthermore, the design of the substrate 310 being adapted to the large surface 210 of the cell 200, combined with the bonding characteristics of the flexible sensor 320, enables the entire measurement module 300 to be stably and reliably integrated into the limited space inside the battery, avoiding interference with the cell structure. While introducing key monitoring functions, it maximizes the preservation of the original high energy density and mechanical strength of the prismatic lithium battery.

[0035] In this embodiment, the specific dimensions (including but not limited to its thickness) of the flexible sensor 320 are not specifically limited. Without departing from the inventive concept of this application, the dimensions can be set according to actual product requirements. As an illustrative rather than restrictive description, the flexible sensor 320 can be a thin sensor with a thickness of 0.7 mm, avoiding increasing the volume or weight of the battery and maintaining a compact battery design.

[0036] It is understandable that the core structure of the battery cell 200 will deform during its service life. Since the thin-film pressure sensor 321 itself has low mechanical strength, if it is placed directly inside the battery cell 200, the deformation of the core structure during its service life may tear the thin-film pressure sensor 321 and cause it to fail. Therefore, in this embodiment, a substrate 310 is added to the measurement module 300, and the thin-film pressure sensor 321 is attached to the substrate 310. The high mechanical rigidity of the substrate 310 prevents the core deformation from tearing the thin-film pressure sensor 321.

[0037] It should be noted that the size and shape of the substrate 310 are not limited in the embodiments of this application. Without departing from the inventive concept of this application, they can be set according to actual product requirements. As an illustrative rather than restrictive description, the substrate 310 may be a polymer with a thickness of 0.5 mm.

[0038] In some specific embodiments, the battery cell 200 has a wound core structure, such as... Figure 1As shown, the core structure is typically a layered structure formed by tightly winding a positive electrode, a separator, and a negative electrode strip. After winding, it appears as a circular or elliptical cross-section when viewed axially; when flattened and placed in a square shell, its two largest, flat surfaces are what we call the "large surfaces." These two large surfaces are precisely the areas formed by countless layers of electrode sheets stacked and wound together. On the one hand, during charging and discharging, the chemical reactions inside the cell (lithium ion insertion and extraction) mainly occur in the electrode material layers throughout the entire large surface area. Therefore, the large surface is the main heat source; heat generated internally needs to pass through layers of electrode sheets and separators before being conducted to the battery casing. This path is long, resulting in a significant lag in the response of external sensors. By directly attaching the flexible sensor 320 to the large surface, the most original and accurate information can be captured directly. On the other hand, when lithium ions shuttle between the positive and negative electrode materials, it causes the materials to undergo minute volume expansion and contraction. In a core structure, this effect accumulates and manifests across the entire surface, resulting in measurable pressure changes.

[0039] In some specific embodiments, the battery cell 200 has a stacked structure, not shown in the figure. The stacked structure is typically formed by stacking positive electrode sheets, negative electrode sheets, and separator sheets layer by layer, like stacking a sandwich, in the order of positive electrode sheet, separator, negative electrode sheet, separator. A basic unit is: separator-positive electrode sheet-separator-negative electrode sheet-separator, and this unit is repeated until a predetermined number of layers is reached. The two large surfaces of the stacked battery cell are the surfaces with the largest projected area in both directions of the entire stacked structure. Because the internal structure of the stacked structure is flatly stacked, its large surfaces have excellent flatness and consistency, and the internal stress distribution is more uniform. Although the internal structure of the stacked structure differs from that of the wound core structure, attaching the measurement module to the large surfaces of the stacked structure is still the best solution for achieving accurate monitoring, for the following reasons: The large surface area of ​​each "sandwich" layer in a laminated battery cell is the primary site of electrochemical reactions and the core area of ​​heat generation. During charging and discharging, each electrode layer undergoes lateral (in-plane) expansion and contraction. Over the entire large surface area, the minute deformations of countless electrode layers accumulate into a macroscopic pressure signal that can be captured by a pressure sensor. This signal is crucial for early warning of battery swelling and performance degradation. The laminated structure itself has shorter and more uniform internal heat conduction paths. Attaching a temperature sensor to the large surface area allows for faster detection of potential localized overheating in any internal layer, as heat can be conducted more directly to the surface, further reducing monitoring lag.

[0040] It should be noted that, in this embodiment of the application, the number of battery cells 200 and measurement modules 300 is not specifically limited. Without departing from the inventive concept of this application, the number of battery cells 200 and measurement modules 300 can be set according to actual product requirements.

[0041] In some specific embodiments, the measurement module 300 is located in the central region of the core structure or the laminated structure. For the core structure, the central region is the axis at the beginning of winding, which is the core where the winding is most tight and heat is most difficult to dissipate; for the laminated structure, the central region is the physical and thermal center after all the electrodes are stacked. The measurement module 300 is integrated into this central region, allowing it to directly contact the center of the heat source and force source of the cell 200.

[0042] It should be noted that heat generation in cell 200 under abnormal operating conditions (such as internal short circuits) typically begins in the central region. Placing the measurement module 300 in this central region allows for the capture of the initial temperature anomaly signal before the heat is conducted to the outer casing, providing the Battery Management System (BMS) with valuable early intervention time and fundamentally solving the problem of lag in external temperature measurement. Both the winding stress of the core and the interlayer stress of the stacked wafers accumulate most significantly in the central region. Gas generation and electrode expansion during battery cycling also first create pressure in the central region. Monitoring pressure at this location yields the most sensitive and intense signal, providing the most sensitive data for diagnosing battery health conditions (such as lithium plating and bulging). Furthermore, the physical parameters (temperature and pressure) in the central region are typically the "limit values" and "benchmark values" for the entire internal state of cell 200. Based on this core data, the BMS's thermal management strategy and life assessment model will be more accurate and conservative, thereby greatly improving the safety redundancy and reliability of battery management.

[0043] The following description uses the example of the battery cell 200 having a wound core structure and the measurement module 300 being located in the central area of ​​the wound core structure to illustrate the solution of this application.

[0044] In some specific embodiments, the flexible sensor 320 includes a thin-film pressure sensor 321. (See also...) Figure 3 and Figure 4 As shown, the thin-film pressure sensor 321 is directly bonded and fixed to the surface of the substrate 310 facing the large surface 210 of the battery cell 200. This mounting method ensures that the sensing surface of the sensor is coplanar with the substrate surface, thereby achieving a large-area, gapless, flat bonding with the large surface 210 of the battery cell 200. The thin-film pressure sensor 321 is a miniaturized, flexible mechanical sensing element manufactured based on flexible printed circuit technology. Its core structure typically consists of two layers of flexible electrodes and a middle layer of pressure-sensitive functional material. When external pressure is applied to the sensor surface, the middle functional material undergoes microscopic deformation, causing a change in its electrical properties, thereby outputting an electrical signal that is specifically related to the applied pressure.

[0045] In this embodiment, the specific dimensions (including but not limited to its thickness) of the thin-film pressure sensor 321 are not specifically limited. Without departing from the inventive concept of this application, the dimensions can be set according to actual product requirements. As an illustrative rather than restrictive description, the thickness of the thin-film pressure sensor 321 can be approximately 0.2 mm. Its size, area, and shape can be flexibly designed and adjusted according to the cell size, covering the entire surface of the core or only a localized area, depending on the monitoring requirements.

[0046] In this embodiment, by flatly bonding the thin-film pressure sensor 321 to the large surface 210 of the battery cell 200, it is ensured that the sensor can directly sense the microscopic volume changes caused by lithium-ion insertion / extraction and the macroscopic pressure fluctuations caused by side reaction gas production during the charging and discharging process of the battery cell 200 without loss. This in-situ measurement method avoids signal attenuation and distortion, providing unprecedented direct data for accurately diagnosing battery health status (such as lithium plating and swelling). The flat bonding structure design ensures that the force-bearing surface of the thin-film pressure sensor 321 maintains uniform and sufficient contact with the large surface 210 of the battery cell 200, effectively avoiding measurement errors and signal fluctuations caused by point contact, local suspension, or stress concentration. This not only ensures the accuracy of a single measurement but also ensures the long-term stability and consistency of the pressure monitoring signal under complex conditions such as vibration and impact throughout the entire battery life. In addition, the thin-film pressure sensor 321 itself is ultra-thin and flexible. Combined with the flat bonding installation method, it is integrated into the surface of the battery cell, occupying almost no additional valuable space inside the battery. This design perfectly maintains the battery's original high energy density while introducing key pressure monitoring functions, thus resolving the core contradiction between increased functionality and space occupancy.

[0047] In some specific embodiments, the flexible sensor 320 can be a composite system integrating multiple physical quantity monitoring functions, including a temperature sensor 322 in addition to the thin-film pressure sensor 321. Further reference... Figure 3 and Figure 4 As shown, to achieve synergistic integration and accurate measurement of the two sensors, in this embodiment, a dedicated mounting groove 311 is formed on the surface of the substrate 310 facing the large surface 210 of the battery cell 200. The temperature sensor 322 is fixedly disposed inside this mounting groove 311; meanwhile, the thin-film pressure sensor 321 is attached to a flat area on the same surface of the substrate 310 where no mounting groove 311 is formed. This arrangement allows the temperature sensor 322 and the thin-film pressure sensor 321 to be physically isolated from each other, yet closely connected through the common substrate 310, together forming a multifunctional monitoring module.

[0048] In some specific embodiments, the temperature sensor 322 can use an NTC thermistor as a probe. It is generally designed with three temperature acquisition points to collect data at the center, bottom, and top of the battery cell, respectively, in order to further monitor the internal temperature distribution of the battery cell.

[0049] It should be noted that the temperature sensor 322 is embedded in the mounting groove 311, allowing it to directly contact the large surface 210 of the battery cell 200 for accurate temperature measurement. Simultaneously, the thin-film pressure sensor 321 is flatly attached to the complete substrate 310 surface. This physical isolation design effectively avoids localized interference from the temperature sensor 322 to the sensing area of ​​the thin-film pressure sensor 321, ensuring the independence and accuracy of the two signal acquisitions. This provides a clean and reliable data foundation for analyzing the complex temperature-pressure coupling relationship within the battery. Furthermore, the mounting groove 311 structure provides precise mechanical positioning and protection for the temperature sensor 322, preventing displacement or damage under long-term battery vibration and expansion stress. The intact, flat substrate reserved for the thin-film pressure sensor 321 ensures a large-area, uniform fit with the large surface 210 of the battery cell 200, thereby guaranteeing high sensitivity and long-term stability of the pressure measurement. This design significantly improves the structural robustness of the entire measurement module.

[0050] Furthermore, through the above solution, two sensing functions can be efficiently integrated within a limited substrate area 310 and an extremely thin space through three-dimensional structural design. This solves the engineering challenge of achieving in-situ monitoring of multiple parameters under the premise of miniaturization. While introducing comprehensive monitoring functions, it minimizes the occupation of valuable space inside the battery, perfectly balancing the dual goals of high energy density and high safety.

[0051] In some specific embodiments, the mounting groove 311 is formed on the surface of the substrate 310 facing the large surface 210 of the cell 200, and extends along the Z-direction or X-direction. In this embodiment, the X-direction is the length direction of the substrate 310, and the Z-direction is the height direction of the substrate 310. Taking the mounting groove 311 extending along the Z-direction as an example, refer to... Figure 4 and Figure 5 As shown, multiple sampling points 312 are planned at preset fixed intervals inside the mounting slot 311. Each sampling point 312 is fixedly equipped with at least one temperature sensor 322, thereby constructing a systematic linear temperature monitoring array in the Z direction.

[0052] Understandably, the extension of the mounting slot 311 along the Z or X direction allows the temperature sensor array 312 to accurately correspond to temperature gradient changes in a specific direction (Z or X), achieving orderly and directional acquisition of the temperature field distribution. The placement of multiple acquisition points 312 at intervals within the mounting slot 311 is equivalent to arranging dense temperature measurement nodes along the monitoring path, enabling the acquisition of continuous, multi-point temperature data. This significantly improves the accuracy and resolution of the analysis of the overall temperature field, especially the temperature gradient changes along the Z direction. The fixed installation of temperature sensors 312 at each acquisition point 312 ensures the accuracy and stability of the positioning of all temperature sensors 312. This not only reduces measurement errors caused by installation deviations and guarantees the consistency of data acquisition at each point, but also lays a solid foundation for the comparability of data from different locations and the stability of long-term monitoring. Furthermore, integrating multiple temperature sensors 312 into a single mounting slot 311 results in a compact structure, saving installation space. This is particularly suitable for applications with limited space or strict layout requirements, achieving high-density deployment and efficient utilization of limited space.

[0053] Further reference Figure 4 and Figure 5 As shown, in some specific embodiments, a wire harness groove 313 is also provided on the surface of the large surface 210 of the substrate 310 facing the cell 200. The wire harness groove 313 extends along the X direction on the surface of the large surface 210. The wire harness groove 313 communicates with the mounting groove 311 and is used to accommodate and fix the data connection cable connected to the temperature sensor 312, so that the data connection cable is guided and constrained in an orderly manner within the wire harness groove 313. Its plug-in end or branch is led out from the preset outlet or opening of the wire harness groove 313 and connected to the corresponding electrical unit. By setting the wire harness groove 313, a clear and fixed physical path can be provided for the arrangement of the data connection cable, ensuring that the wiring work is standardized and uniform, avoiding random wiring, and centrally storing multiple scattered data connection cables in a unified channel (i.e., the wire harness groove 313), which greatly optimizes the space utilization, makes the inside of the equipment neat and orderly, and avoids the messiness of the wire harness.

[0054] Further reference Figure 4 As shown, in some specific embodiments, at least one measuring module 300 also includes an adhesive 330. The thin-film pressure sensor 321 is firmly attached to the surface of the substrate 310 by uniformly coated adhesive 330; at the same time, the temperature sensor 322 is also stably encapsulated and fixed inside the corresponding mounting groove 311 by filling or dotting adhesive 330.

[0055] In this embodiment, adhesive 330 provides a unified and reliable fixing solution for the thin-film pressure sensor 321 and temperature sensor 322, ensuring a firm physical connection between all sensing elements and the substrate 310 and mounting groove 311. This effectively prevents sensor displacement or loosening due to vibration, impact, or thermal expansion and contraction, ensuring long-term measurement stability. Specifically, for the thin-film pressure sensor 321, the uniform adhesive layer ensures a tight, gapless fit between its sensing surface and the measured surface (or substrate 310), thereby accurately transmitting pressure signals. For the temperature sensor 322, adhesive 330 fills the gap between the sensor and the wall of the mounting groove 311, reducing contact thermal resistance and ensuring fast and accurate temperature response. Using adhesive 330 as a fixing medium avoids the need for mechanical fasteners in a compact space, achieving seamless integration of the sensor and substrate 310. This process not only simplifies the structural design but also makes the entire measurement module 300 a more robust and integrated functional unit, improving the module's overall integrity and durability.

[0056] In some specific embodiments, adhesive 330 possesses a certain elastic modulus, thereby maintaining good adhesion at different temperatures and withstanding certain environmental stresses. Its elastic properties can absorb some mechanical and thermal stresses, providing buffer protection for delicate sensor components and reducing the risk of damage due to stress concentration.

[0057] Further reference Figure 1 and Figure 2 As shown, in some specific embodiments, the prismatic lithium battery integrates a data connection line 400. One end of the data connection line 400 is electrically interconnected and communicatively connected to the flexible sensor 320 inside the housing 100, while the other end extends reliably to the outside of the housing 100 through a specific sealing structure, forming a standardized external data interface.

[0058] In some specific embodiments, the data connection line 400 is based on a flexible printed circuit board (PCB). The PCB's thin, flat, and customizable physical characteristics allow it to fully utilize the limited space inside the battery for wiring. Its flat structure facilitates a tight fit with the casing's penetration points, enabling high-standard laser welding or potting sealant, thus significantly improving the battery's overall airtightness and safety. Compared to ordinary round cable bundles, the wiring inside the flexible PCB is firmly attached to the substrate 310, with uniform line spacing. This structure effectively reduces signal attenuation and electromagnetic interference during transmission. Furthermore, its excellent bending and vibration resistance allows it to adapt to the micro-motion environment during long-term battery use, extending the lifespan of the connection lines.

[0059] By connecting one end of the data connection cable 400 directly to the flexible sensor 320 and leading the other end out to the outside of the housing 100, a stable and low-loss internal signal transmission channel is constructed, ensuring that temperature sensing signals and other signals can be transmitted to external monitoring equipment with extremely high reliability, effectively avoiding signal interruption problems caused by poor wire welding or vibration.

[0060] Further reference Figure 1 and Figure 2 As shown, in some specific embodiments, the housing 100 adopts a split design, including a main body 110 with an opening and a matching cover 120. The interior of the main body 110 forms a sealed receiving space 130 for accommodating the battery cell 200 and the measurement module 300, while the cover 120 is encapsulated over the opening of the main body 110 to reliably seal the receiving space 130. This split design of the main body 110 and the cover 120 greatly facilitates the insertion, installation, and wiring of the battery cell 200 and the measurement module 300. When maintenance or replacement of internal components is required, only the cover 120 needs to be opened for operation, significantly improving product maintainability and production assembly efficiency.

[0061] To facilitate the external transmission of internal signals, the data connection cable 400 passes through a specially designed through-hole 121 in the cover 120 and ultimately extends to the outside of the housing 100. To ensure the sealing integrity of the housing 100, reliable sealing structures (not shown) are provided at all gaps between the data connection cable 400 and the inner wall of the through-hole 121. In this embodiment, by creating a through-hole 121 in the cover 120 and providing a sealing structure to facilitate signal transmission, the opening that could compromise the seal is strictly limited to a localized area and compensated for through a professional sealing process. This achieves the desired functionality while maximizing the protection of the battery housing's overall critical safety performance, such as leak-proof, explosion-proof, dustproof, and moisture-proof properties. Furthermore, the combined design of the through-hole 121 and the sealing structure provides a clear and robust exit point for the data connection cable 400. This structure effectively buffers the stress transmitted to the data cable from external pulling or internal vibration, preventing stress from directly acting on fragile internal solder joints or the sensor itself, thus improving the long-term reliability of the electrical connection.

[0062] In some specific embodiments, the data connection line 400 is provided for connection to the battery management system (BMS). The BMS processes and analyzes the received temperature and pressure signals, monitors the battery's operating status in real time, and takes timely protective measures, such as cutting off the power or issuing an alarm, in abnormal situations.

[0063] Example 2 The difference from Embodiment 1 is that, in this embodiment, the mounting slot 311 includes at least two. Taking two mounting slots 311 as an example, refer to... Figure 6 As shown, the two mounting slots 311 are arranged in parallel with a certain distance along the X direction. The length direction of each mounting slot 311 extends along the Z direction, which is perpendicular to the X direction, thereby forming two independent and parallel linear mounting structures on the surface of the substrate 310.

[0064] By arranging two mounting slots 311 spaced apart in the X direction and extending along the Z direction, a single linear monitoring path is expanded into a two-dimensional monitoring area. This allows the temperature sensor 322 to cover a wider area, thereby capturing temperature gradients and distribution differences that may exist in the XZ plane, achieving an upgrade from line-to-area monitoring. Furthermore, the two mounting slots 311 form parallel and independent monitoring paths. For example, by comparing data at corresponding points on the two paths, cross-validation can be performed to effectively identify faults or local anomalies in a single temperature sensor 322, greatly improving the reliability and data credibility of the entire temperature measurement system. The spacing in the X direction enables direct detection and quantification of temperature changes along the X direction (i.e., lateral gradients), a function that a single mounting slot 311 cannot achieve. This is crucial for analyzing the temperature uniformity of large-area heat sources or identifying the location of local hot spots.

[0065] Example 3 The difference from Example 2 is that, referring to Figure 7 As shown in the embodiment of this application, the two mounting slots 311 are arranged parallel to each other with a certain distance along the Z direction, and the wire harness slot 313 extends along the Z direction on the surface of the large surface 210. The length direction of each mounting slot 311 extends along the X direction perpendicular to the Z direction, thereby forming two strip-shaped mounting areas that are staggered in the Z direction and parallel in the X direction on the surface of the substrate 310.

[0066] By arranging two mounting slots 311 extending along the X direction at intervals along the Z direction, data acquisition can be performed at different Z-direction heights within the same plane. This layout facilitates direct capture and comparative analysis of potential temperature gradients or differences along the Z direction, providing crucial longitudinal dimension data for thermal field distribution. Furthermore, the two parallel mounting slots 311 extending along the X direction constitute independent monitoring channels. This design allows for data cross-calibration at points at the same X-axis position but different Z-axis heights, not only verifying the accuracy of individual sensors but also providing backup data in case of partial failure in a channel, enhancing the overall fault tolerance and reliability of the system. In addition, distributing the temperature sensor 322 array across the two parallel X-direction mounting slots 311 avoids thermal buildup interference or signal crosstalk that might result from concentrating all temperature sensors 322 in a single narrow area. This distributed layout allows the temperature sensors 322 to perceive the true temperature state of the measured surface more uniformly, reducing the impact of the measurement system itself on the measurement environment.

[0067] Example 4 The difference from Embodiment 1 is that, in this embodiment, the measurement module 300 is disposed between two adjacent wound core structures or two adjacent laminated structures. Taking the battery cell 200 as an example of a wound core structure, refer to... Figure 8 As shown, the number of battery cells 200 includes at least two, which are housed in the same housing 100 in a side-by-side or stacked manner, and the measuring module 300 is disposed at the interface between two adjacent core structures. Preferably, a measuring module 300 is disposed at the interface between every two adjacent core structures.

[0068] Specifically, regardless of whether adjacent cells are wound or stacked, the substrate 310 of each measurement module 300 and its flexible sensor 320 are adapted and attached to the large surfaces of the two cells, thereby enabling independent, in-situ monitoring of the individual state of each cell. On one hand, this design constructs a distributed sensor network within the battery, enabling the battery management system (BMS) to independently and in real-time acquire the interface temperature and pressure data of each cell. When a cell exhibits thermal anomalies or abnormal expansion, the system can immediately and accurately locate the issue, implementing targeted cooling or isolation measures, effectively solving the overall safety bottleneck of the battery pack caused by the "weakest link" effect. On the other hand, multiple cells will develop performance differences (such as internal resistance and capacity decay) during cyclic use. The measurement modules 300 positioned between the cells 200 can directly monitor the thermal and mechanical behavior of these inconsistencies (e.g., a cell consistently having a higher temperature and expanding faster), providing direct data for the BMS to perform precise equalization control, thus delaying overall battery pack performance degradation and improving system lifespan. Furthermore, in extreme situations such as thermal runaway, heat can be transferred between adjacent cells. Monitoring the temperature at the interface between cells allows for real-time tracking of the path and speed of heat propagation, providing crucial time and data support for the BMS to initiate cascaded protection measures (such as enhanced cooling of adjacent cells and emergency power cut-off), preventing thermal runaway from spreading throughout the battery pack.

[0069] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] Furthermore, the terms "first" and "second" are used 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 as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] 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 according to the specific circumstances.

[0073] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A prismatic lithium battery, characterized in that, The lithium battery includes a housing (100) and at least one cell (200) and at least one measuring module (300) disposed inside the housing (100). At least one of the measurement modules (300) includes a substrate (310) and a flexible sensor (320) disposed on the substrate (310), the substrate (310) being adapted to the large surface (210) of at least one of the battery cells (200), and the flexible sensor (320) being attached to the large surface (210) of at least one battery cell (200).

2. The prismatic lithium battery according to claim 1, characterized in that, At least one of the battery cells (200) is in the form of a wound core structure or a stacked structure; At least one of the measurement modules (300) is disposed in the central region of the core structure or the stacked structure; or, the number of the cells (200) includes at least two, and each of the measurement modules (300) is disposed between two adjacent core structures or two adjacent stacked structures.

3. The prismatic lithium battery according to claim 1 or 2, characterized in that, The flexible sensor (320) includes a thin-film pressure sensor (321), which is attached to the surface of the substrate (310) facing the large surface (210) and is flatly attached to the large surface (210).

4. The prismatic lithium battery according to claim 3, characterized in that, The flexible sensor (320) also includes a temperature sensor (322). The substrate (310) has a mounting groove (311) on the surface facing the large surface (210). The temperature sensor (322) is fixedly disposed in the mounting groove (311). The thin film pressure sensor (321) is attached to the surface of the substrate (310) facing the large surface (210) where the mounting groove (311) is not provided.

5. The prismatic lithium battery according to claim 4, characterized in that, At least one of the measurement modules (300) further includes an adhesive (330) by which the thin-film pressure sensor (321) is fixed to the substrate (310) and the temperature sensor (322) is fixed in the mounting groove (311) by the adhesive (330).

6. The prismatic lithium battery according to claim 4, characterized in that, The mounting groove (311) is located on the surface of the substrate (310) facing the large surface (210). The mounting groove (311) extends along the X direction or Z direction on the surface. Multiple sampling points (312) are arranged at intervals in the mounting groove (311). At least one temperature sensor (322) is fixedly arranged in each sampling point (312). The X direction is the length direction of the substrate (310), and the Z direction is the height direction of the substrate (310).

7. The prismatic lithium battery according to claim 6, characterized in that, The mounting groove (311) includes one, which is located at the center of the surface and the length of the mounting groove (311) extends along the X or Z direction on the surface.

8. The prismatic lithium battery according to claim 6, characterized in that, The mounting slot (311) includes at least two, the at least two mounting slots (311) are arranged at intervals along the X direction on the surface and the length direction of the at least two mounting slots (311) extends along the Z direction on the surface; Alternatively, at least two of the mounting slots (311) are arranged at intervals along the Z direction on the surface and the length direction of at least two of the mounting slots (311) extends along the X direction on the surface.

9. The prismatic lithium battery according to claim 1 or 2, characterized in that, The prismatic lithium battery also includes a data connection line (400), one end of which is connected to the flexible sensor (320) for communication, and the other end extends through the housing (100) to the outside of the housing (100). The data connection line (400) is a flexible printed circuit board.

10. The prismatic lithium battery according to claim 9, characterized in that, The housing (100) includes a main body (110) and a cover (120). The main body (110) forms a receiving space (130) for accommodating the battery cell (200) and the measuring module (300). The cover (120) is disposed at the opening of the main body (110) to close the receiving space (130). The data connection line (400) passes through the cover (120) through a through hole (121) on the cover (120) and extends to the outside of the receiving space (130). The gap between the data connection line (400) and the through hole (121) is provided with a sealing structure.

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