Battery structure embedded with optical fiber sensor and battery pack

Abstract

The embodiment of the invention provides a battery structure embedded with an optical fiber sensor and a battery pack, and relates to the technical field of battery monitoring. The battery structure embedded with the optical fiber sensor comprises a battery cell shell, a battery cell roll core, a support body, the optical fiber sensor and a sealing element, wherein the battery cell roll core is arranged in the battery cell shell; the support body is arranged at a position close to the electrode in the battery core roll core; a nick groove is formed in the outer surface of the supporting body; the optical fiber sensor is embedded in the nick groove and fixedly connected with the supporting body, the optical fiber sensor is provided with a leading-out end, and the leading-out end extends out of the interior of the battery core roll core; the sealing element is arranged at the end part of the battery cell roll core and is connected with the battery cell shell; the sealing element is provided with a through hole, the leading-out end penetrates through the through hole, and the through hole is sealed through the sealing element. The safety or performance problem caused by the fact that an optical fiber sensor is directly implanted into the middle of the battery cell roll core can be avoided, the accuracy of collecting data in the battery cell roll core can be improved, and the sealing performance of the structure of the battery cell roll core can be improved.

Description

Technical Field

[0001] This invention relates to the field of battery monitoring technology, and more specifically, to a battery structure and battery pack with an embedded fiber optic sensor. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage technologies, lithium-ion batteries, as a core power source, have become crucial for monitoring their safety, lifespan, and performance status. Direct and accurate measurement of the internal state of the battery cell, such as temperature and strain, is of great significance for achieving intelligent battery management, early warning of thermal runaway, and prediction of remaining lifespan. Fiber optic sensors are widely used for battery internal state monitoring due to their advantages such as small size, resistance to electromagnetic interference, corrosion resistance, and the ability to perform multi-point distributed measurements. Existing technologies include solutions that directly embed fiber optic sensors inside the battery core.

[0003] However, directly embedding rigid or semi-rigid fiber optic sensors into the highly precise internal structure of battery cells may present the following problems: First, forcibly embedding such sensors can damage the original structure of the electrode layers and separators, introducing localized stress concentration points. This could not only lead to the shedding of active materials and reduced battery performance, but also pose a safety risk of internal short circuits and subsequent thermal runaway. Second, due to the complexity and spatial uncertainty of the internal structure of the battery cell core, directly embedded fiber optic sensors cannot guarantee a stable and tight fit with the measured area (such as the electrode surface). Poor contact can lead to increased thermal resistance and distorted strain transmission, ultimately resulting in significant deviations in measurement data that fail to accurately reflect changes in the internal physical state of the battery cell. Summary of the Invention

[0004] This invention provides a battery structure and battery pack with an embedded fiber optic sensor, which can avoid the safety or performance problems caused by directly implanting the fiber optic sensor in the middle of the battery cell core, improve the accuracy of collecting data inside the battery cell core, and also improve the sealing performance of its own structure.

[0005] The embodiments of the present invention can be implemented as follows: Embodiments of the present invention provide a battery structure with an embedded fiber optic sensor, comprising: Battery cell casing; A battery cell winding core, wherein the battery cell winding core is disposed inside the battery cell housing; A support body is disposed inside the battery cell winding core near the electrode; the outer surface of the support body is provided with a groove. An optical fiber sensor is embedded in the groove and fixedly connected to the support. The optical fiber sensor has a lead-out end that extends from the inside of the battery cell winding core. A sealing element is disposed at the end of the battery cell winding core and connected to the battery cell housing; the sealing element has a through hole, the lead-out end passes through the through hole, and the sealing element achieves a seal at the through hole.

[0006] In an optional embodiment, the support is made of a material that expands and contracts with temperature. The support can expand in volume after being heated or absorbing electrolyte, so that the fiber optic sensor fits tightly against the inner wall of the battery core.

[0007] In an optional embodiment, the support is made of at least one material selected from shape memory alloy, shape memory polymer, thermoplastic polyurethane, thermoplastic polyurethane elastomer, or silicone.

[0008] In an optional embodiment, the support body has an internal filling cavity for filling with a highly thermally conductive porous material and / or an insulating coolant.

[0009] In an optional embodiment, the high thermal conductivity porous material is copper foam, aluminum foam, or high thermal conductivity carbon material, and the surface of the high thermal conductivity porous material is treated with insulation.

[0010] In an optional embodiment, there are multiple grooves and multiple fiber optic sensors, with the grooves spaced apart and each groove corresponding to a fiber optic sensor.

[0011] In an optional implementation, some of the fiber optic sensors are used to detect temperature signals, and some of the fiber optic sensors are used to detect strain and temperature coupled signals.

[0012] In an optional implementation, the fiber optic sensor is a multi-grating sensor or a distributed fiber optic sensor.

[0013] In an optional embodiment, the sealing element includes a sealing pin and a sealing plug. The sealing pin is fixedly connected to the battery cell housing and has a through hole. The sealing plug is disposed in the through hole and achieves sealing by compression deformation.

[0014] Embodiments of the present invention also provide a battery pack, including a housing and a battery structure with an embedded fiber optic sensor as described in any of the above embodiments, wherein a plurality of the battery structures with embedded fiber optic sensors are connected in series and / or in parallel, and are all installed in the housing.

[0015] The beneficial effects of the battery structure and battery pack of the embedded fiber optic sensor in this invention include, for example: The battery structure with an embedded fiber optic sensor includes a battery cell housing, a battery cell core, a support, a fiber optic sensor, and a seal. The battery cell core is housed within the battery cell housing. The support is positioned inside the battery cell core near the electrodes. The outer surface of the support has grooves. The fiber optic sensor is embedded within these grooves and fixedly connected to the support. The fiber optic sensor has an extension end that protrudes from the inside of the battery cell core. The seal is located at the end of the battery cell core and connected to the battery cell housing. The seal has a through-hole through which the extension end passes, and the through-hole is sealed. Directly embedding the fiber optic sensor inside the battery cell core may not guarantee a proper fit, potentially leading to significant measurement data deviations. By fixing the fiber optic sensor to the outer surface of the support and then implanting the support inside the battery cell core near the electrodes, precise embedding of the fiber optic sensor can be achieved, improving the accuracy of data acquisition from within the battery cell core. Furthermore, embedding the fiber optic sensor through the support avoids safety or performance issues that might arise from implanting it in the middle of the battery cell core. By incorporating a seal, it is ensured that the implantation of the fiber optic sensor will not result in leakage, thus improving the sealing performance of the battery structure with the embedded fiber optic sensor. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a battery structure with an embedded fiber optic sensor provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the support body and fiber optic sensor after assembly in an embodiment of the present invention, from a first-view perspective. Figure 3 This is a schematic diagram of the support body and fiber optic sensor after assembly in an embodiment of the present invention, from a second perspective. Figure 4 This is a schematic diagram of a sealing element provided in an embodiment of the present invention.

[0018] Icons: 1000 - Battery structure with embedded fiber optic sensor; 100 - Cell casing; 200 - Cell winding; 300 - Support; 310 - Score groove; 320 - Filling cavity; 400 - Fiber optic sensor; 410 - Lead-out end; 500 - Seal; 510 - Sealing pin; 511 - Through hole; 520 - Sealing plug. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention 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 invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] With the rapid development of new energy vehicles and energy storage technologies, lithium-ion batteries, as core power sources, have become crucial for monitoring their safety, lifespan, and performance status. Direct and accurate measurement of the internal state of the battery cell, such as temperature and strain, is essential for intelligent battery management, early warning of thermal runaway, and prediction of remaining lifespan. Fiber optic sensors, due to their small size, resistance to electromagnetic interference, corrosion resistance, and ability to perform multi-point distributed measurements, are widely used for monitoring the internal state of batteries. Existing technologies include methods for directly embedding fiber optic sensors inside the battery core. However, directly embedding rigid or semi-rigid fiber optic sensors into the highly precise battery core may present the following problems: First, forced implantation can easily damage the original structure of the electrode layer and separator, introducing localized stress concentration points. This could not only lead to the shedding of active materials and reduced battery performance but also pose a safety risk of internal short circuits and subsequent thermal runaway. Second, due to the complexity and spatial uncertainty of the internal structure of the battery core, directly embedded fiber optic sensors cannot guarantee a stable and tight fit with the measured area (such as the electrode surface). Poor contact can lead to increased thermal resistance and distorted strain transmission, ultimately resulting in large deviations in measurement data that cannot accurately reflect changes in the internal physical state of the battery cell.

[0026] Based on this, please refer to Figures 1-3 The battery structure 1000 with embedded fiber optic sensor provided in the embodiments of the present invention can effectively improve the aforementioned technical problems. This battery structure 1000 with embedded fiber optic sensor can avoid safety or performance problems caused by directly embedding the fiber optic sensor 400 in the middle of the battery cell winding core 200, and can also improve the accuracy of data acquisition from inside the battery cell winding core 200, as well as improve the sealing performance of its own structure. This battery structure 1000 with embedded fiber optic sensor can be applied to battery packs, which can be used in electric vehicles and other electrical devices. Devices with this battery structure 1000 with embedded fiber optic sensor all have the same functions as described above.

[0027] This invention provides a battery pack comprising a housing and multiple battery structures 1000 with embedded fiber optic sensors. The multiple battery structures 1000 with embedded fiber optic sensors are connected in series and / or in parallel, and are all installed within the housing. The battery pack also includes a battery management system, which is communicatively connected to the fiber optic sensors 400 in each of the embedded fiber optic sensor battery structures 1000. The battery management system receives and processes temperature and / or strain signals collected by the fiber optic sensors 400. The battery management system is configured to: construct a temperature distribution model inside the battery pack based on temperature signals; adjust the operating strategy of the thermal management components connected to the housing according to the temperature distribution model; thereby optimizing the cooling strategy of the battery pack's thermal management components; determine the battery status; and prevent thermal runaway based on the determined battery status. Optionally, the battery management system in this embodiment is configured to: analyze the health status of the multiple battery structures 1000 with embedded fiber optic sensors based on strain signals; and predict their performance degradation trends, thereby predicting in advance when the performance of the battery structure will significantly degrade or age, so as to replace it in time and prevent safety problems after the battery structure ages.

[0028] The following is a detailed description of the battery structure 1000 with embedded fiber optic sensors.

[0029] Figure 1 This is a schematic diagram of a battery structure 1000 with an embedded fiber optic sensor provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the support 300 and the fiber optic sensor 400 after assembly in an embodiment of the present invention. Figure 3 This is a schematic diagram from a second perspective showing the assembly of the support 300 and the fiber optic sensor 400 in an embodiment of the present invention. Figures 1-3As shown, the battery structure 1000 with embedded fiber optic sensor provided in the embodiment of the present invention includes a battery cell housing 100, a battery cell core 200, a support body 300, a fiber optic sensor 400, and a sealing member 500. The battery cell core 200 is disposed inside the battery cell housing 100; the support body 300 is disposed inside the battery cell core 200 near the electrode; a groove 310 is formed on the outer surface of the support body 300; the fiber optic sensor 400 is embedded in the groove 310 and fixedly connected to the support body 300, and the fiber optic sensor 400 has a lead-out end 410 that extends from inside the battery cell core 200; the sealing member 500 is disposed at the end of the battery cell core 200 and connected to the battery cell housing 100; the sealing member 500 has a through hole 511, the lead-out end 410 passes through the through hole 511, and the sealing member 500 achieves sealing at the through hole 511. Directly embedding the fiber optic sensor 400 inside the battery cell core 200 may not guarantee a proper fit between the sensor and the core, potentially leading to significant measurement data deviations. By fixing the fiber optic sensor 400 to the outer surface of the support 300, and then implanting the support 300 inside the battery cell core 200 near the electrode surface, precise embedding of the fiber optic sensor 400 can be achieved, improving the accuracy of data acquisition from within the battery cell core 200. Furthermore, embedding the fiber optic sensor 400 through the support 300 avoids safety or performance issues that might arise from implantation within the battery cell core 200. The sealing element 500 ensures that the implantation of the fiber optic sensor 400 will not result in leakage, improving the sealing performance of the battery structure 1000 with the embedded fiber optic sensor.

[0030] In this embodiment, fixing the fiber optic sensor 400 to the surface of the support 300 reduces the number of turns inside the diaphragm of the battery cell core 200 and loosens the internal diaphragm during the implantation process. Furthermore, by introducing the fiber optic sensor 400 into the central blank area of ​​the battery cell core 200 through the support 300, and by bringing the fiber optic sensor 400 close to the central electrode of the battery cell core 200, the accuracy of collecting temperature and strain data from the central electrode of the battery cell is improved. This also avoids safety and performance issues caused by introducing foreign objects into the middle of the core, which could lead to strain concentration and localized lithium plating.

[0031] Optionally, in this embodiment, the groove 310 is engraved on the outer surface of the support 300 by means of laser engraving, CNC engraving, or a scratch tester, with micron-sized grooves slightly larger than the diameter of the fiber optic sensor 400, in order to accommodate and fix the fiber optic sensor 400.

[0032] To further achieve seamless bonding between the fiber optic sensor 400 and the battery cell core 200, the support 300 in this embodiment is made of a material that expands and contracts with temperature. The support 300 expands in volume when heated or after absorbing electrolyte, allowing the fiber optic sensor 400 to adhere tightly to the inner wall of the battery cell core 200, thus enabling accurate acquisition of temperature and strain data of the battery cell's intermediate electrode. After embedding the support 300 with the fiber optic sensor 400 inside the battery cell core 200, the heat generated during the battery's formation, baking, or normal operation causes the support 300 to expand, making it adhere tightly to the inner wall of the battery cell core 200. This ensures the fiber optic sensor 400 is in close contact with the location to be detected, improving the accuracy of the acquired data. Furthermore, based on the thermal expansion and contraction characteristics, the support 300 with the embedded fiber optic sensor 400 can be adapted to battery cells of different diameters, improving versatility.

[0033] Optionally, the support 300 in this embodiment is made of at least one material selected from shape memory alloy, shape memory polymer, thermoplastic polyurethane, thermoplastic polyurethane elastomer (TPU), or silicone. These materials possess good flexibility, elasticity, or deformability. When the support 300 is implanted inside the battery cell core 200, under the heat generated during battery formation, baking, or normal operation, the support 300 (especially the shape memory alloy / polymer) will undergo controllable volume expansion or shape recovery; or it will swell by absorbing electrolyte (such as TPU or silicone). This expansion force can push the fiber optic sensor 400 fixed thereon to fit tightly and firmly against the inner wall or electrode surface of the battery cell core 200, greatly reducing the contact thermal resistance and mechanical gap between the sensor and the measurement point. This ensures the real-time transmission of temperature signals and the fidelity of strain signal transmission, thereby fundamentally improving the accuracy and reliability of data acquisition of the battery cell's internal state.

[0034] Directly implanting the fiber optic sensor 400 into the battery cell core 200 will damage the electrode layer and separator, causing tight contact between the electrode and separator, resulting in localized stress concentration points. This can easily lead to internal short circuits and thermal runaway. If the sensor is embedded between the cores, it can easily cause active material to detach, reducing battery performance. Compared with the method of forcibly inserting the rigid fiber optic sensor 400 into the core, this embodiment first pre-fixes the sensor onto a relatively flexible support 300, forming an integrated "sensor-support 300" module. This module causes less impact and damage to the internal structure of the battery cell core 200 during implantation. The subsequent expansion behavior of the support 300 can automatically compensate for installation gaps and manufacturing tolerances, reducing the precision requirements of the implantation process, making the implantation operation simpler and more controllable, which is conducive to large-scale production and improves the manufacturing yield of the battery cell. Because the material of the support 300 itself is flexible, its expansion process is gradual and gentle, rather than rigid extrusion. This effectively avoids dangerous local stress concentration points inside the core, significantly reducing the risk of damage to the separator, micro-short circuits, or loss of active materials due to the implantation of foreign objects, thereby fundamentally ensuring the intrinsic safety and cycle life of the battery.

[0035] Polymer materials such as TPU and silicone have good resistance to electrolyte corrosion and chemical stability, which can maintain the integrity of the battery's structure and function throughout its entire life cycle. They will not generate impurities due to degradation, thus ensuring the reliability and stability of the battery's long-term operation.

[0036] The center point of the 200-inch battery cell winding is furthest from the outer casing, resulting in the longest heat dissipation path. Heat transfer from the center to the circumference must pass through all the dense winding layers, which is inefficient and leads to high internal temperatures, severely impacting the cell's performance, lifespan, and safety. Therefore, please refer to... Figure 3In this embodiment, the support 300 has a filling cavity 320 inside, which is used to fill with a highly thermally conductive porous material and / or an insulating coolant. The center of the cell core 200 is the area with the longest heat dissipation path and where heat is most easily accumulated. By setting the filling cavity 320 and filling it with a highly thermally conductive porous material or an insulating coolant, the heat generated by the cell core 200 can be quickly dissipated through the support 300 or exchanged with the support 300 to achieve rapid cooling. The support 300 can quickly dissipate the heat to the cell casing 100. Through the above design, the heat generated by the electrode during charging and discharging, especially under high-rate conditions such as fast charging and fast discharging, can be quickly conducted to the battery casing and dissipated, effectively suppressing the radial temperature difference inside the cell core 200, avoiding local overheating, thereby improving the battery's cycle life, safety performance, and applicable scenarios. The aforementioned heat dissipation effect allows for a more uniform and stable internal temperature field within the battery cell winding core 200. A uniform temperature field means that the temperature measured by the fiber optic sensor 400 is more representative of the overall state of the battery cell winding core 200, rather than an isolated, potentially overheated "hot spot," making the temperature monitoring data more representative and instructive. Furthermore, by integrating the heat dissipation function and the support and fixation of the fiber optic sensor 400 into the same support structure 300, there is no need to introduce separate heat dissipation components within the limited internal space of the battery cell winding core 200, saving space and thus contributing to improved energy density of the battery cell.

[0037] Optionally, the high thermal conductivity porous material in this embodiment is foamed copper, foamed aluminum, or high thermal conductivity carbon material, and the surface of the high thermal conductivity porous material is treated with insulation. The insulating coolant can be a fluorinated liquid, etc., and is not limited thereto. By opening a filling cavity 320 in the support 300 and filling the filling cavity 320 with high thermal conductivity porous material and / or insulating coolant, the heat inside the cell core 200 can be quickly discharged through the cell shell 100, realizing heat dissipation inside the cell core 200, which helps to suppress radial temperature difference inside the battery, avoid local overheating, and improve battery life and safety. This battery structure is also suitable for high heat generation scenarios such as fast charging and fast discharging, and can effectively control battery temperature rise.

[0038] To acquire signals from multiple locations within the battery cell winding 200, the fiber optic sensor 400 in this embodiment is a multi-grating sensor or a distributed fiber optic sensor 400. Optionally, the total length of the signal detection area in this embodiment is equal to the height of the battery cell winding 200, enabling a single fiber to detect temperature signals at multiple locations vertically to the center of the cylindrical battery cell winding 200, thereby reducing the number of fiber optic sensors 400 required.

[0039] Optionally, in this embodiment, there are multiple notches 310 and fiber optic sensors 400, with the notches 310 spaced apart and each notch 310 corresponding to an embedded fiber optic sensor 400. By setting multiple notches 310 at different axial heights and / or circumferential positions on the support 300, a vertically distributed monitoring network can be constructed along the central axis of the cell core 200. This allows the system to simultaneously acquire temperature and / or strain signals at different locations inside the cell core 200, thereby obtaining the temperature gradient distribution and strain changes along the axial direction of the cell core 200, achieving a panoramic perception of the internal state of the cell core 200. The acquired axial temperature distribution data can be used to construct a more accurate three-dimensional battery thermal model, thereby guiding differentiated and precise thermal management of battery pack-level liquid cooling systems, avoiding global overcooling or insufficient cooling. Meanwhile, strain data at different heights can more comprehensively reflect the evolution of the mechanical behavior of the entire core during cycling, providing a rich data foundation for more accurate assessment of battery state of health (SOH) and prediction of remaining life (RUL).

[0040] Furthermore, single-point monitoring may miss localized hotspots or mechanical failures occurring in other locations. This embodiment, through a multi-point spatial layout, can capture abnormalities occurring at any location within the battery cell, such as localized overheating or abnormal strain caused by lithium plating. When the data from a fiber optic sensor 400 at a certain point is abnormal, the system can immediately pinpoint the specific axial location of the fault or risk, providing spatial location capabilities for fault diagnosis and precise intervention, greatly improving the intelligence and safety of battery management. Moreover, the multiple fiber optic sensors 400 in this embodiment constitute a redundant monitoring system. Even if a single fiber optic sensor 400 fails after long-term operation, the remaining fiber optic sensors 400 can continue to operate, ensuring the continuity of the condition monitoring function and the robustness of the entire system, avoiding the paralysis of the entire monitoring system due to a single-point failure.

[0041] Optionally, in this embodiment, some fiber optic sensors 400 are used to detect temperature signals, and some fiber optic sensors 400 are used to detect strain and temperature coupling signals. At least one fiber optic sensor 400 is encapsulated after its surface is embedded in the support 300. In this embodiment, PTFE (polytetrafluoroethylene) is used for encapsulation; however, other materials with waterproof and corrosion-resistant properties can also be used, and this is not limited. The encapsulated fiber optic sensor 400 is used to detect temperature. At least one fiber optic sensor 400 is not encapsulated; the unencapsulated fiber optic sensor 400 is used to simultaneously detect temperature and strain signals. The fiber optic sensor 400 is sensitive to both strain and temperature, directly measuring the coupling signal between the two. By simultaneously acquiring high-precision internal temperature field and mechanical strain field information, the system can construct more complex battery state assessment models. By setting up a dedicated sensor for temperature monitoring, a temperature reference value unaffected by mechanical strain can be obtained. Using this undisturbed temperature value, temperature compensation calculations can be performed on the sensors measuring strain and temperature coupling signals, thereby accurately decoupling and separating the true strain value. The above design eliminates strain measurement errors caused by temperature changes, ensuring the accuracy and reliability of strain data and laying a solid foundation for accurately assessing the battery's health status. The detected temperature data can be directly used to monitor thermal runaway and optimize thermal management. The decoupled pure strain data more directly reflects the physical changes of the cell during cycling, such as electrode expansion and contraction caused by lithium insertion / extraction, abnormal volume expansion caused by lithium plating, and changes in mechanical properties due to separator aging. Fusing temperature and strain data allows for multi-dimensional, cross-validation of the battery's health and safety status, significantly improving the confidence level of the state estimation.

[0042] An independent temperature monitoring network can quickly respond to any localized overheating. Simultaneously, by analyzing the decoupled strain data, abnormal mechanical deformations unrelated to temperature changes can be identified, such as localized bulging due to internal short circuits or lithium plating. When the system detects "decoupling anomalies"—such as normal temperature but a sharp increase in strain, or normal strain but an abnormally high temperature—different levels of safety warnings can be triggered, enabling earlier and more accurate fault diagnosis and location.

[0043] Traditional methods seal the optical fiber lead-out points with adhesive. However, in the later stages of battery operation, the aging or easy detachment of the adhesive can lead to electrolyte leakage or water infiltration, which can cause battery safety failures, sudden performance reduction, and decreased cycle stability.

[0044] Figure 4 This is a schematic diagram of the seal 500 provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 4In this embodiment, the sealing element 500 includes a sealing pin 510 and a sealing plug 520. The sealing pin 510 is fixedly connected to the battery cell housing 100, and the sealing pin 510 has a through hole 511. The sealing plug 520 is disposed in the through hole 511 and achieves a seal through compression deformation. In this embodiment, the sealing pin 510 is connected and fixed to the battery cell housing 100 through a mechanical structure such as a threaded structure or a snap-fit ​​structure, or the sealing pin 510 is connected to the battery cell housing 100 by welding or other methods. The sealing plug 520 is disposed at the through hole 511 and achieves a seal through compression to ensure that no leakage occurs after the fiber optic sensor 400 is implanted, thereby improving the sealing performance of the integrated battery cell of the fiber optic sensor 400. Of course, the sealing element 500 can also be other sealing structures, such as using sealant or epoxy resin to seal the connection between the lead-out end 410 and the battery cell housing 100, which is not limited here.

[0045] In this embodiment, the support 300 is a hollow columnar structure. Of course, the support 300 can also be designed as a cuboid or other shapes, which are not limited here.

[0046] The battery structure in this embodiment is a cylindrical wound cell. Of course, the battery structure can also be a square wound cell or a pouch cell, and is not limited here.

[0047] The installation process of the battery structure 1000 with an embedded fiber optic sensor provided in this embodiment is as follows: One installation process is as follows: First, drill a round hole in the top cover of the battery cell housing 100, with a diameter larger than that of the fiber optic sensor 400. Then, wind the positive electrode, separator, and negative electrode of the battery cell to form a battery cell core 200. Select an FBG (fiber Bragg grating) temperature and strain fiber optic sensor 400 with multiple grating regions, pass it through a sealing pin 510 through a through hole 511, and seal the through hole 511 with a sealing plug 520. Next, introduce the grating region (signal monitoring part) of the fiber optic sensor 400 into the blank area in the center of the core, and insert a support body 300 into the blank area in the center of the core, so that the fiber optic sensor 400 is embedded in the groove 310 of the support body 300. Assemble the core, battery cell housing 100, top cover, etc., and bake at high temperature to ensure that the support body 300 undergoes phase change volume expansion, so as to achieve a close fit between the fiber optic sensor 400 and the inside of the core. Finally, connect and fix the sealing pin 510 to the top cover of the battery cell housing 100.

[0048] The battery structure 1000 with embedded fiber optic sensor can also be installed as follows: First, drill a circular hole in the top cover of the cell housing 100, with a diameter larger than that of the fiber optic sensor 400. Then, wind the positive electrode, separator, and negative electrode of the cell to form a cell core 200. Select a through hole 511 through which the distributed fiber optic sensor 400 passes a sealing pin 510, and seal the through hole 511 with a sealing plug 520. Then, introduce the signal monitoring area of ​​the fiber optic sensor 400 into the blank area at the center of the core, place the cell core 200 into the cell housing 100, and insert a support 300 with a filling cavity 320, such as a thermoplastic polyurethane (TPU) thin-walled flexible tube, into the center of the cell core 200 to ensure contact between the tube and the battery housing. Inject fluorinated coolant into the filling cavity 320, and then seal the support 300. The support 300 expands and fits tightly against the inner wall of the cell core 200, ensuring that the fiber optic sensor 400 is tightly attached to the inner electrode. Next, the cell casing 100, top cover, etc., are assembled and baked at high temperature. The sealing nail 510 is then connected and fixed to the top cover. Finally, the cell is sealed and injected with electrolyte, and subsequent cell trial production steps are carried out to complete the cell trial production.

[0049] Alternatively, the fiber optic sensor 400 can be embedded and fixed in the groove 310 of the support 300 to form an integral structure. Then, this integral structure can be implanted into the test area of ​​the battery core 200. If the fiber optic sensor 400 is not fully attached to the test position after assembly, the support 300 can be expanded to make the fiber optic sensor 400 fully attached to the test position. If the fiber optic sensor 400 is fully attached to the test position after assembly, there is no need to expand the support 300.

[0050] In summary, the battery structure 1000 with embedded fiber optic sensor includes a battery cell housing 100, a battery cell core 200, a support body 300, a fiber optic sensor 400, and a sealing element 500. The battery cell core 200 is disposed inside the battery cell housing 100; the support body 300 is disposed inside the battery cell core 200 near the electrode; a groove 310 is formed on the outer surface of the support body 300; the fiber optic sensor 400 is embedded in the groove 310 and fixedly connected to the support body 300, and the fiber optic sensor 400 has a lead-out end 410 that extends from inside the battery cell core 200; the sealing element 500 is disposed at the end of the battery cell core 200 and connected to the battery cell housing 100; the sealing element 500 has a through hole 511, through which the lead-out end 410 passes, and the sealing element 500 achieves a seal at the through hole 511. Directly embedding the fiber optic sensor 400 inside the battery cell core 200 may not guarantee a proper fit between the sensor and the core, potentially leading to significant measurement data deviations. By fixing the fiber optic sensor 400 to the outer surface of the support 300, and then implanting the support 300 inside the battery cell core 200 near the electrode surface, precise embedding of the fiber optic sensor 400 can be achieved, improving the accuracy of data acquisition from within the battery cell core 200. Furthermore, embedding the fiber optic sensor 400 through the support 300 avoids safety or performance issues that might arise from implantation within the battery cell core 200. The sealing element 500 ensures that the implantation of the fiber optic sensor 400 will not result in leakage, improving the sealing performance of the battery structure 1000 with the embedded fiber optic sensor.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A battery structure with an embedded fiber optic sensor, characterized in that, include: Battery cell casing (100); A battery cell core (200) is disposed inside the battery cell housing (100); A support body (300) is disposed inside the battery cell core (200) near the electrode; the outer surface of the support body (300) is provided with a groove (310). An optical fiber sensor (400) is embedded in the groove (310) and fixedly connected to the support (300). The optical fiber sensor (400) has a lead-out end (410) that extends from the inside of the battery cell winding core (200). A sealing element (500) is disposed at the end of the battery cell winding core (200) and connected to the battery cell housing (100); the sealing element (500) has a through hole (511), the lead end (410) passes through the through hole (511), and the sealing of the through hole (511) is achieved by the sealing element (500).

2. The battery structure with an embedded fiber optic sensor according to claim 1, characterized in that, The support (300) is made of a material that expands and contracts with temperature. The support (300) can expand in volume after being heated or absorbing electrolyte, so that the fiber optic sensor (400) is tightly attached to the inner wall of the battery core (200).

3. The battery structure with an embedded fiber optic sensor according to claim 2, characterized in that, The support (300) is made of at least one material selected from shape memory alloy, shape memory polymer, thermoplastic polyurethane, thermoplastic polyurethane elastomer or silicone.

4. The battery structure with an embedded fiber optic sensor according to claim 1, characterized in that, The support (300) has a filling cavity (320) inside, which is used to fill a highly thermally conductive porous material and / or an insulating coolant.

5. The battery structure with an embedded fiber optic sensor according to claim 4, characterized in that, The high thermal conductivity porous material is copper foam, aluminum foam, or high thermal conductivity carbon material, and the surface of the high thermal conductivity porous material is treated with insulation.

6. The battery structure with an embedded fiber optic sensor according to claim 1, characterized in that, The number of the grooves (310) and the fiber optic sensors (400) are both multiple, and the multiple grooves (310) are spaced apart, with each groove (310) corresponding to a fiber optic sensor (400).

7. The battery structure with an embedded fiber optic sensor according to claim 6, characterized in that, The fiber optic sensor (400) is used in part to detect temperature signals and in part to detect strain and temperature coupled signals.

8. The battery structure with an embedded fiber optic sensor according to claim 1, characterized in that, The fiber optic sensor (400) is a multi-grating sensor or a distributed fiber optic sensor (400).

9. The battery structure with an embedded fiber optic sensor according to any one of claims 1-8, characterized in that, The sealing element (500) includes a sealing pin (510) and a sealing plug (520). The sealing pin (510) is fixedly connected to the battery cell housing (100), and the sealing pin (510) has the through hole (511). The sealing plug (520) is disposed in the through hole (511) and achieves sealing by extrusion deformation.

10. A battery pack, characterized in that, The device includes a housing and a plurality of battery structures (1000) for embedded fiber optic sensors as described in any one of claims 1-9, wherein the plurality of battery structures (1000) for embedded fiber optic sensors are connected in series and / or in parallel, and are all installed within the housing.

Images