A wireless optical fiber sensing based battery cell, battery pack and built-in monitoring system

Abstract

This invention belongs to the field of smart battery technology and discloses a battery cell, battery pack, and built-in monitoring system based on wireless fiber optic sensing. The battery cell incorporates a fiber optic sensing module, which includes first and second fiber optic sensing structures respectively disposed between the positive and negative electrodes and the separator. These fiber optic sensing structures are converged via a two-in-one fiber optic cable, and the fiber end faces are processed into fiber optic lenses. Furthermore, the explosion-proof valve of the battery cell is made in the form of a lens and optically coupled to the fiber optic lens. This invention enables independent and high-precision monitoring of each battery cell through built-in and wireless transmission, offering higher safety, flexibility, and reusability compared to existing technologies. It also allows for real-time monitoring of the internal health status of the battery cell in applications such as energy storage systems and new energy vehicles without the need for secondary wiring and installation.

Description

Technical Field

[0001] This invention belongs to the field of smart battery technology, and more specifically, relates to a battery cell, battery pack and built-in monitoring system based on wireless fiber optic sensing. Background Technology

[0002] With the rapid development of global industries such as manufacturing, AI, and data centers, the demand for energy is also rising rapidly. For various new energy batteries, including lithium-ion batteries, their cells have become one of the core components for energy storage and conversion due to their high energy density, long lifespan, and high efficiency. They are widely used in large-scale energy storage stations, new energy vehicles, and other fields. However, safety issues such as battery failure and thermal runaway occur frequently, making it imperative to improve the safety of battery cells.

[0003] In recent decades, many complex BMS (battery management systems) have been developed to improve reliability and lifespan, but the results have been mediocre. The core problem is that long-standing cell management has relied on monitoring surface temperature measured from the cell's exterior and voltage and current collected from the electrodes, with surface temperature typically monitored using discrete temperature sensors. This combination of voltage and current monitoring inherently suffers from low spatial resolution, severe hysteresis, and other drawbacks. Furthermore, each individual cell exhibits different temperatures during operation, with the internal and external temperature differences exceeding 20°C. Even when the internal temperature of a cell reaches 50°C, the surface temperature may temporarily remain around 25°C. Therefore, incomplete cell monitoring coverage and discrepancies between internal and external testing constitute one of the key technical challenges in this field. To address these issues, developing technologies capable of real-time monitoring of the cell's internal state has become an inevitable trend.

[0004] The search revealed that some existing solutions to the above-mentioned technical pain points include the following:

[0005] The first approach involves drilling additional holes in the cell's cover plate or using a liquid injection port to bring out the signal harness of the internal sensors. However, this approach has several drawbacks. First, it poses a safety risk of damaging the battery's sealed structure. Second, even if each cell is brought out, monitoring each cell within a power battery pack would require hundreds more electrical wires / fiber optic cables, making wiring and cabling extremely difficult. Furthermore, the implantation and extraction process would necessitate modifications to the entire production process and significantly reduce the production efficiency of the cells / battery packs, making it impractical at the industrial level.

[0006] The second approach involves arranging various sensors and chips inside the battery cell and collecting reflected light signals caused by abnormal conditions within the cell via optical fiber, thereby monitoring the cell's operating status. For example, patent document CN118888890A discloses a battery, a battery system, and sensors; patent document WO2022056957A1 discloses a smart battery; and patent document CN117878461A discloses a battery pack and a method for detecting the air pressure inside the battery pack. However, while these existing solutions can achieve built-in monitoring to some extent, they still require the arrangement of complex sensing elements and electrical modules, which not only causes inconvenience in battery cell manufacturing but also easily leads to losses in monitoring accuracy and efficiency. Furthermore, in the electromagnetic environment of the entire battery pack, the complexity of individual battery cells and their insufficient anti-interference capabilities also bring a series of additional challenges to the stability and reliability of the entire battery pack.

[0007] On the other hand, in the energy storage field, in order to reduce the safety risks of energy storage stations and improve inspection quality and operational efficiency, more and more companies are using intelligent inspection equipment as a common tool for inspecting energy storage stations. However, existing inspection solutions still mostly rely on external detection methods such as video and infrared, which cannot effectively detect the actual condition inside the battery cells of the energy storage station. Furthermore, in the field of new energy vehicles, current battery monitoring solutions have not fully integrated with the needs of in-vehicle application scenarios, nor have they adequately designed their layout and operation.

[0008] Accordingly, there is an urgent need in this field to conduct research and improvements in order to better solve the aforementioned technical problems. Summary of the Invention

[0009] To address one or more of the above-mentioned defects or improvement needs of existing technologies, this invention provides a battery cell, battery pack, and built-in monitoring system based on wireless fiber optic sensing. By redesigning the structure and composition of the battery cell, especially improving the structure and arrangement of some key components such as explosion-proof valves, fiber optic sensing modules, and top covers, this invention not only enables more precise real-time monitoring of the internal state of multiple areas within the battery cell, but also achieves wireless passive transmission monitoring of multiple parameters in multiple areas within the battery cell. Furthermore, the battery cell production process does not require the introduction of additional complex processes such as wiring, lead wires, and connection.

[0010] Building upon this foundation, the present invention further enables wireless transmission detection within multiple cells of a single light source by designing a matching battery pack, its beam splitter module, and lower housing structure. This reduces the amount of wiring harnesses for sensors within the battery pack, achieving a balance between lightweight design and efficient detection. By incorporating a mobile robot into the design of an integrated energy storage system monitoring system, a single inspection robot can monitor the reusability of each cell in the entire energy storage station's battery cluster, reducing wiring workload by over 90%. Simultaneously, it enables precise thermal management at the cell level, achieving unmanned operation and remote diagnostics for new energy storage stations. Furthermore, by fully integrating the battery monitoring characteristics and specific requirements of new energy vehicles, and utilizing the vehicle-mounted optical communication network and the data processing capabilities of the vehicle-mounted ECU / GPU architecture, the invention achieves precise capture of the microscopic state of the battery pack cells.

[0011] To achieve the above objectives, according to a first aspect of the present invention, a battery cell based on wireless fiber optic sensing is provided. The battery cell includes a housing, a positive electrode, a negative electrode, a diaphragm, and an explosion-proof valve, wherein:

[0012] The battery cell has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber and the end face of the fiber is processed into a fiber optic lens.

[0013] The explosion-proof valve is mounted on the housing and is made in the form of a lens, and is optically coupled to the fiber optic lens.

[0014] As a further preferred embodiment of the present invention, the battery cell is also equipped with an upper cover, which includes an upper cover plate, a lower plastic layer, an air vent array, and a sleeve. The explosion-proof valve is installed between the upper cover plate and the lower plastic layer. The sleeve is located below the explosion-proof valve and is sleeved with the fiber optic lens. The air vent array is located around the sleeve and is aligned and connected to the sleeve and the explosion-proof valve with their central axes coinciding. The sleeve is used to protect and limit the fiber optic lens.

[0015] As a further preferred embodiment of the present invention, the first and second fiber optic sensing structures employ fiber gratings to perform real-time acquisition of data on the internal state of the battery cell, including temperature, deformation, and air pressure.

[0016] As a further preferred embodiment of the present invention, the number and / or type of the first and second fiber optic sensing structures are multiple, and they are installed in series to realize multi-physical monitoring and cross-decoupling.

[0017] As a further preferred embodiment of the present invention, the fiber optic lens is processed into a conical structure.

[0018] As a further preferred embodiment of the present invention, the explosion-proof valve is made in the form of a glass circular lens, which serves as both a pressure relief device for the battery cell and a transmission medium for optical signals entering and exiting the battery cell.

[0019] As a further preferred embodiment of the present invention, the fiber optic sensing module utilizes the electrolyte injected into the battery cell to achieve optical axis alignment and stability between the fiber optic lens and the sleeve.

[0020] According to a second aspect of the present invention, a battery pack based on wireless fiber optic sensing is also provided, the battery pack comprising a light source, a beam splitter, and a plurality of battery cells arranged side by side, wherein:

[0021] Each of the aforementioned battery cells includes a housing, a positive electrode, a negative electrode, a diaphragm, and an explosion-proof valve, and incorporates a fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the diaphragm, and a second fiber optic sensing structure disposed between the negative electrode and the diaphragm. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. Furthermore, the explosion-proof valve is mounted on the housing, is made in the form of a lens, and is optically coupled to the fiber optic lens.

[0022] The number of beam splitters is multiple, and they are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the explosion-proof valve.

[0023] The light source is used to provide uniform parallel collimated light for the multiple beam splitters, and the light enters the corresponding explosion-proof valve through reflection from each beam splitter, while it is transmitted to the next adjacent beam splitter through transmission from each beam splitter.

[0024] As a further preferred embodiment of the present invention, the light source is built into the vicinity of the battery management system of the battery pack itself, and is directly powered by the voltage system of the battery management system.

[0025] As a further preferred embodiment of the present invention, the battery pack is also equipped with a lower housing for supporting and installing all the battery cells, and has a transparent window for exposing the explosion-proof valve of each battery cell and the optical fiber lens coupled to it.

[0026] As a further preferred embodiment of the present invention, the lower housing is a detachable and reusable independent structure, and there is no wire connection between it and the battery cell.

[0027] As a further preferred embodiment of the present invention, the light source is a broadband light source with a spectral bandwidth of 400nm to 2000nm, and its output beam is a parallel collimated beam with a spot diameter of 0.1mm to 1mm.

[0028] As a further preferred embodiment of the present invention, the beam splitter's beam splitting ratio, i.e., the ratio of reflection to transmission, is limited, wherein the reflection ratio is less than 10% and the transmission ratio is greater than 90%.

[0029] As a further preferred embodiment of the present invention, the beam splitter ratio, i.e., the reflection-to-transmission ratio, is set to 1:99.

[0030] According to a third aspect of the invention, a built-in monitoring system for an energy storage system is also provided, the system comprising an inspection robot, a light source, and a battery cluster integrated from one or more battery packs, wherein:

[0031] Each battery pack includes a battery cell and a beam splitter. Each battery cell includes a housing, a positive electrode, a negative electrode, a separator, and an explosion-proof valve, and has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. In addition, the explosion-proof valve is mounted on the housing and is made in the form of a lens, and optical path coupling is achieved between it and the fiber optic lens.

[0032] The number of beam splitters is multiple, and they are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the explosion-proof valve, and the splitting ratio, that is, the reflection and transmission ratio, of each beam splitter is the same.

[0033] The light source is used to provide uniform parallel collimated light for the multiple beam splitters, and the light enters the corresponding explosion-proof valve through the reflection of each beam splitter, and is transmitted to the next adjacent beam splitter through the transmission of each beam splitter.

[0034] The inspection robot is placed on a track arranged around the battery cluster. It moves along a preset inspection route and has a built-in fiber optic demodulation device for receiving and analyzing optical information transmitted by each of the fiber optic sensing modules through the explosion-proof valve, which carries the internal status information of the battery cells.

[0035] As a further preferred embodiment of the present invention, the inspection robot, based on the received light information, initially predicts the remaining lifespan of the battery cell and diagnoses fault information, and then transmits it to the cloud server, thereby establishing a battery cell-level information database for the entire energy storage system.

[0036] According to a fourth aspect of the present invention, a built-in monitoring system for new energy vehicles is also provided, the system comprising a battery pack, an on-board optical communication unit, and an on-board processor, wherein:

[0037] The battery pack includes a light source, a beam splitter, and multiple battery cells arranged side by side. Each battery cell includes a housing, a positive electrode, a negative electrode, a separator, and an explosion-proof valve, and has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. In addition, the explosion-proof valve is mounted on the housing and is made in the form of a lens, and optical path coupling is achieved between it and the fiber optic lens.

[0038] The number of beam splitters is multiple, and they are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the explosion-proof valve, and the splitting ratio, that is, the reflection and transmission ratio, of each beam splitter is the same.

[0039] The light source is used to provide uniform parallel collimated light for the multiple beam splitters, and the light enters the corresponding explosion-proof valve through the reflection of each beam splitter, and is transmitted to the next adjacent beam splitter through the transmission of each beam splitter.

[0040] The vehicle-mounted optical communication unit is used to receive optical information transmitted by each of the optical fiber sensing modules through the explosion-proof valve, which carries the internal status information of the battery cell, and transmit it to the vehicle-mounted processor.

[0041] The vehicle-mounted processor processes the data from the vehicle-mounted optical communication unit and obtains the real-time status of the battery cell.

[0042] As a further preferred embodiment of the present invention, the vehicle-mounted optical communication unit and the vehicle-mounted processor are both inherent functional units of the new energy vehicle itself.

[0043] As a further preferred embodiment of the present invention, the vehicle-mounted processor performs data processing in a closed loop of perception-transmission-computation-decision-execution, and transmits the real-time status of the battery cell to the battery management system of the battery pack through the vehicle-mounted optical communication unit, thereby realizing battery health management.

[0044] In summary, the technical solutions conceived by this invention have the following main technical advantages compared with the prior art:

[0045] (1) This invention arranges multiple fiber optic sensing units inside the battery cell and processes them into a two-in-one fiber optic lens, which is suitable for clever cooperation with the explosion-proof valve made of lens. It can not only use fiber optic sensing to perform real-time perception of the internal state of the battery cell in multiple areas, but also use the lens structure to achieve a large receiving angle for wireless beam transmission. Accordingly, it can perform the battery cell monitoring process with higher precision, realize the wireless passive transmission monitoring process of multiple areas and multiple parameters inside the battery cell, and the battery cell production process does not need to introduce additional wiring, lead wires, wiring and other complex processes. In addition, the explosion-proof valve in this invention can also use the optical characteristics of the glass lens and the controllable fracture characteristics to realize multiple functions of safe pressure relief and visual monitoring.

[0046] (2) The present invention further makes targeted improvements to the spectral monitoring process and working mechanism of the battery pack, which can realize wireless transmission monitoring of multiple cells with multiple channels of a single light source. It reduces a large number of sensor wiring harnesses inside the battery pack, and the signal has no significant difference throughout the detection process, which greatly improves the working efficiency and monitoring accuracy of the battery pack monitoring, and at the same time helps to achieve lightweighting. In addition, by improving the matching lower box, the advantages of compact structure, wireless wiring connection with the cells, and easy secondary use can be obtained.

[0047] (3) The present invention further makes targeted improvements to the built-in monitoring system applicable to the field of energy storage. By using a single inspection robot and a single demodulation module, the reusable wireless monitoring function of the internal state of each cell of all battery clusters in the energy storage system can be realized, reducing the wiring workload by more than 90%. At the same time, the installation cost and hardware cost are greatly reduced, and the unattended and remote diagnostic operation mode of the energy storage system can be realized.

[0048] (4) The present invention further makes targeted improvements to the built-in monitoring system for battery packs applicable to vehicle application scenarios. By making reasonable use of the vehicle's own on-board optical communication unit and on-board ECU / GPU architecture, the built-in fiber optic sensor of the present invention can be reasonably arranged in the vehicle environment. It can achieve lightweight vehicle monitoring without secondary wiring and installation, and at the same time realize the accurate capture of the micro-state of the battery pack cell structure, and provide a basis for battery health assessment.

[0049] (5) Based on the insulation of the lens structure and the high anti-interference and stability of wireless signal transmission, the above-mentioned improved solution of the present invention further combines the advantages of built-in fiber optic sensing structure and wireless transmission, which can realize independent high-precision detection of each cell. Compared with the prior art, it has the advantages of high safety, high plasticity and reusability, and thus has important significance for improving the service life and safety of the cell. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of a battery cell based on wireless fiber optic sensing designed according to the first scheme of this application;

[0051] Figure 2 It is used for more specific display Figure 1 A schematic diagram of the explosion-proof valve and fiber optic lens shown in the figure;

[0052] Figure 3 This is a schematic diagram of the structure of the top cover of the battery cell according to a preferred embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of the structure of a battery pack based on wireless fiber optic sensing designed according to the second scheme of the present invention;

[0054] Figure 5 It is used for more specific display Figure 4 A side view of the lower housing of the battery pack shown in the diagram;

[0055] Figure 6 This is a schematic diagram of an application of an inspection robot to perform reusability monitoring of an energy storage system, designed according to the third embodiment of the present invention.

[0056] Figure 7 This is a schematic diagram of an application of online monitoring of a battery pack combined with an in-vehicle optical communication system, designed according to the fourth embodiment of the present invention.

[0057] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0058] 1-1. Positive electrode; 1-2. Negative electrode; 1-3. Separator; 1-4. Housing; 1-5. Explosion-proof valve; 1-6. Fiber optic lens; 1-7. Two-in-one fiber optic cable; 1-8. First fiber optic sensing element; 1-9. Second fiber optic sensing element; 3-1. Top cover plate; 3-2. Plastic under the top cover; 3-4. Vent array; 3-5. Sleeve; 4-1. Fiber optic sensing cell; 4-2. Battery management system; 4-3. Light source; 4-4. Beam splitter; 4-5. Reflected beam from the beam splitter; 4-6. Transmitted beam from the beam splitter; 6-1. Lower housing; 6-2. Glass window; 7-1. Inspection robot; 7-2. Inspection route; 7-3. Inspection endpoint; 7-4. Beam carrying internal cell status information. Detailed Implementation

[0059] 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. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this invention.

[0061] 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 invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0064] Figure 1 This is a schematic diagram of the structure of a battery cell based on wireless fiber optic sensing, designed according to the first scheme of this application. Figure 2 It is used for more specific display Figure 1 The diagram shows the structure of the explosion-proof valve and fiber optic lens. The following will refer to... Figure 1 and Figure 2 To explain the invention in more detail.

[0065] like Figure 1 and Figure 2 As shown, this invention designs a novel battery cell based on wireless fiber optic sensing. In addition to conventional components such as a housing 1-4, a positive electrode 1-1, a negative electrode 1-2, a diaphragm 1-3, and an explosion-proof valve 1-5, the battery cell also includes a built-in fiber optic sensing module. This fiber optic sensing module includes a first fiber optic sensing structure 1-8 disposed between the positive electrode 1-1 and the diaphragm 1-3, and a second fiber optic sensing structure 1-9 disposed between the negative electrode 1-2 and the diaphragm 1-3. The first and second fiber optic sensing structures are joined by a two-in-one fiber optic cable 1-7, the end face of which is processed into a fiber optic lens 1-6. Furthermore, this invention makes corresponding adjustments and improvements to the explosion-proof valve 1-5. It is mounted on the housing 1-4 and is made into a lens structure, such as a glass circular lens, and achieves optical path coupling with the fiber optic lens 1-6.

[0066] More specifically, the lens-shaped explosion-proof valves 1-5 of the present invention are used to release pressure and reduce the risk of explosion when the battery malfunctions and the internal pressure increases to a certain value. However, unlike conventional explosion-proof valves, the explosion-proof valves of the present invention are made in the form of a lens structure. This allows the high light transmittance and controllable fracture characteristics of the optical lens to serve as a pressure relief device for the battery cell, precisely opening to release pressure when the internal pressure of the battery cell rises abnormally, while maintaining the sealing performance under normal conditions. On the other hand, it can also serve as a medium for optical signal transmission, effectively transmitting the optical signals collected inside the battery cell using spatial optical transmission wireless transmission, while focusing and collimating the transmitted beam.

[0067] More specifically, the fiber optic sensing module of the present invention includes two fiber optic sensing structures, which are respectively placed between the positive electrode and the separator and between the negative electrode and the separator to collect real-time data on the internal state of the battery cell, including data such as temperature, deformation, and air pressure inside the battery cell. Based on this, the present invention uses a two-in-one fiber or fiber bundle to converge and then processes its end face with a fiber optic lens, such as a conical structure. This can make full use of the unique mode field expansion, geometric focusing, and angle tolerance characteristics of the lens fiber, significantly improving the tolerance of lateral, longitudinal, and angular deviations, and is used for receiving and transmitting optical signals at large angles.

[0068] According to a preferred embodiment of the present invention, a matching top cover structure for the battery cell is also designed. For example... Figure 3 As shown, the battery cell housing of the present invention includes an upper top cover, which includes a cover plate, an air hole array 3-4, and a sleeve 3-5. The cover plate is composed of an upper top cover plate 3-1 and a lower top cover plastic 3-2. An explosion-proof valve 1-5 is installed inside the cover plate and between the upper top cover plate 3-1 and the upper top cover plastic 3-2. The sleeve 3-5 is located below the explosion-proof valve 1-5 and is sleeved with the fiber optic lens 1-6. The air hole array 3-4 is arranged around the sleeve 3-5 and below the cover plate, and is then aligned and connected with the sleeve 3-5 and the explosion-proof valve 1-5 with their central axes coinciding. The sleeve 3-5 is used to protect and limit the fiber optic lens 1-6.

[0069] More specifically, the aforementioned sleeves 3-5 are, for example, in the form of quartz sleeves, used to better achieve effective coupling and assembly of the lens-type explosion-proof valve and the two-in-one fiber optic sensing module designed in this invention. See also Figure 3 By utilizing the sleeve 3-5 on the lower side of the pore array 3-4 (the inner diameter of the sleeve is 0.1mm to 1mm larger than the outer diameter of the fiber optic lens 1-6), the fiber optic lens part of the two-in-one fiber optic sensing module can be effectively protected, while limiting the movement within a certain range in the X-axis and Y-axis directions.

[0070] According to another preferred embodiment of the present invention, the first and second fiber optic sensing structures adopt fiber optic gratings or other fiber optic sensing units to perform real-time acquisition of data on the internal state of the battery cell, including temperature, deformation, and air pressure.

[0071] According to another preferred embodiment of the present invention, the number and / or type of the first and second optical fiber sensing structures are multiple, and they are installed in series to realize multi-physical monitoring and cross-decoupling.

[0072] Furthermore, according to another preferred embodiment of the present invention, by injecting electrolyte into the above-mentioned battery cell, the optical fiber can have a stable characteristic of automatic centering by utilizing the hydrodynamic centering force mechanism, thereby achieving relative stability between the optical fiber lens and the sleeve, and more effectively realizing optical coupling transmission with the lens-type explosion-proof valve.

[0073] Through the above design, the battery cell structure of the present invention is simple and controllable in the entire battery cell production process. The two-in-one fiber optic sensing module can be installed in the battery cell, placed in the aluminum alloy shell, and then aligned and assembled with the sleeve and the lens-shaped explosion-proof valve. After the electrolyte is injected and sealed at the injection port, the production process is completed, which is basically the same as the ordinary battery cell production process, without the need for additional wiring, lead wires, wiring and other complex processes.

[0074] It should be noted that the battery cells of the present invention can be placed independently in the battery pack, without module design or additional wiring harness connection, and the battery cells can be replaced individually after failure.

[0075] Figure 4 This is a schematic diagram of the battery pack based on wireless fiber optic sensing designed according to the second aspect of the present invention. Figure 4 As shown, the present invention also designs a novel battery pack based on wireless fiber optic sensing. In addition to including 2x21 battery cells arranged in a matrix, the battery pack also includes components such as a light source and a beam splitter.

[0076] For each battery cell, it is the wireless fiber optic sensing-based cell 4-1 designed as above, which includes a housing, a positive electrode, a negative electrode, a diaphragm, and an explosion-proof valve, and has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the diaphragm, and a second fiber optic sensing structure disposed between the negative electrode and the diaphragm. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. In addition, the explosion-proof valve is mounted on the housing, is made in the form of a lens, and is optically coupled with the fiber optic lens.

[0077] There are multiple beam splitters 4-4, arranged along the optical path corresponding to each of the aforementioned battery cells 4-1, with each beam splitter aligned with the optical axis of the battery cell's explosion-proof valve. The light source 4-3 provides uniform parallel collimated light to the multiple beam splitters 4-4, which is reflected by each beam splitter 4-4 and enters the corresponding wireless fiber optic sensing battery cell 4-1. Simultaneously, it is transmitted through each beam splitter to the next adjacent beam splitter. Multiple light sources can be used for one-to-one monitoring; however, one or two light sources are preferred to reduce the number of active terminals.

[0078] More specifically, the light source 4-3 is, for example, an SLD light source, preferably a broadband light source with a spectral bandwidth of 400nm to 000nm, and its output beam is a parallel collimated light with a spot diameter of 0.1mm to 1mm; the light source can be built into the battery management system 4-2 and directly powered by the low-voltage system of the BMS.

[0079] The beam splitter 4-4, i.e., the reflection-to-transmission ratio, can be designed to be the same, preferably a beam splitter with a preset beam splitting ratio of 1:99, to achieve serial multi-channel transmission of optical signals. Figure 4As shown in the diagram, 4-5 represent the reflected beams of each beam splitter, and 4-6 represent the transmitted beams of each beam splitter. During monitoring, the optical signal transmission process can be explained as follows: Taking a 100mW SLD light source as an example, after passing through the first beam splitter, 1mW of light is reflected into the first fiber optic sensing cell, 99mW of light is transmitted to the second beam splitter, and after passing through the second beam splitter, 0.99mW of light is reflected into the second fiber optic sensing cell, and 98.01mW of light is transmitted to the third beam splitter. This series transmission continues until the 100th cell, where the light power intensity is 0.366mW, with an attenuation of <10dB and no significant signal difference, achieving multi-channel transmission from a single light source. Figure 5 As shown, according to another preferred embodiment of the present invention, the battery pack is further equipped with a lower housing 6-1, which is used to support and install all the fiber optic sensing cells 4-1, and has a transparent window, such as a glass window 6-2, to expose the explosion-proof valves of each fiber optic sensing cell and the fiber optic lenses coupled to them in the optical path. Furthermore, the lower housing 6-1 is a detachable and reusable independent structure.

[0080] Figure 6 This is a schematic diagram of an application of the third scheme of the present invention, which uses an inspection robot to perform reusability monitoring on an energy storage system.

[0081] like Figure 6 As shown, the present invention also designs a built-in monitoring system for energy storage systems, which includes an inspection robot and a battery cluster integrated from one or more battery packs, wherein:

[0082] Each of the aforementioned battery packs includes a battery cell and a beam splitter. Each battery cell includes a housing, a positive electrode, a negative electrode, a separator, and an explosion-proof valve, and has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. In addition, the explosion-proof valve is mounted on the housing, is made in the form of a lens, and is optically coupled to the fiber optic lens.

[0083] There are multiple beam splitters, which are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the battery cell explosion-proof valve, and the splitting ratio, i.e., the reflection and transmission ratio, of each beam splitter is the same. The light source is used to provide uniform parallel collimated light to the multiple beam splitters, and the light enters the corresponding battery cell explosion-proof valve through reflection by each beam splitter, and is transmitted to the next adjacent beam splitter through transmission by each beam splitter.

[0084] The inspection robot 7-1 is a single unmanned device placed on a track arranged around the battery cluster. It moves along a preset inspection route 7-2 and has a built-in fiber optic demodulation device for receiving and analyzing optical information transmitted by each of the fiber optic sensing modules through the explosion-proof valve, which carries the internal status information of the battery cells, until it reaches the inspection endpoint 7-3.

[0085] More specifically, see Figure 6 The inspection robot 7-1 is placed on tracks on both sides of the battery pack in the energy storage station. The SLD light source built into the battery management system 4-2 transmits light to the wireless fiber optic sensing cells. The beam 7-4, carrying the internal state information of the cells, is transmitted through the glass window via the fiber optic lens. The inspection robot receives the signal and couples the optical path with the wireless fiber optic sensing battery pack to wirelessly transmit the optical signal. In this way, by moving along the inspection route 7-2, the robot collects the battery state information of each fiber optic sensing cell in the wireless fiber optic sensing battery pack, and makes a preliminary prediction of the remaining life of the cells and diagnoses fault information. The information is then transmitted to the cloud server of the energy storage station, which enables the construction of a multi-physics model and the establishment of a database at the cell level for the entire energy storage station.

[0086] Figure 7 This is a schematic diagram illustrating the application of online monitoring of the battery pack using a vehicle-mounted optical communication system, designed according to the fourth aspect of this invention.

[0087] like Figure 7 As shown in the figure, the present invention also designs a built-in monitoring system for new energy vehicles, which includes a battery pack, an on-board optical communication unit, and an on-board processor, wherein:

[0088] The battery pack includes a light source, a beam splitter, and multiple battery cells arranged side by side. Each battery cell includes a housing, a positive electrode, a negative electrode, a separator, and an explosion-proof valve, and has a built-in fiber optic sensing module. The fiber optic sensing module includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber optic cable, and the end face of the fiber optic cable is processed into a fiber optic lens. In addition, the explosion-proof valve is mounted on the housing, is made in the form of a lens, and is optically coupled to the fiber optic lens.

[0089] There are multiple beam splitters, which are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the battery cell explosion-proof valve, and the splitting ratio, i.e., the reflection and transmission ratio, of each beam splitter is the same. The light source is used to provide uniform parallel collimated light to the multiple beam splitters, and the light enters the corresponding battery cell explosion-proof valve through reflection by each beam splitter, and is transmitted to the next adjacent beam splitter through transmission by each beam splitter.

[0090] In addition, the vehicle-mounted optical communication unit is used to receive optical information carrying the internal status information of the battery cell transmitted by each of the optical fiber sensing modules through the explosion-proof valve, and transmit it to the vehicle-mounted processor; the vehicle-mounted processor processes the data from the vehicle-mounted optical communication unit and obtains the real-time status of the battery cell.

[0091] More specifically, see Figure 7 In the application of new energy vehicles, this invention utilizes an on-board optical communication network to receive light information carrying the internal physical state of the battery cell transmitted from the SLD light source built into the BMS to the fiber optic sensing cell. The light information is then transmitted through the glass window via the fiber optic lens. By processing the data in the on-board ECU and GPU units, multi-physics field data analysis is performed on each battery cell, and a battery health status model can be constructed. The real-time status feedback of the battery cell is then transmitted to the BMS via the on-board optical communication network, thereby realizing battery health management.

[0092] The present invention also provides some specific embodiments in order to more fully explain and illustrate the present invention.

[0093] Example 1

[0094] This embodiment provides a battery cell based on wireless fiber optic sensing. The battery cell includes: a positive electrode, a negative electrode, a separator, an aluminum alloy shell, an explosion-proof valve in the form of a circular lens, a fiber optic lens, a two-in-one fiber optic cable, a first fiber optic sensing structure (fiber optic grating or other fiber optic sensing unit) between the positive electrode and the separator, and a second fiber optic sensing structure (fiber optic grating or other fiber optic sensing unit) between the negative electrode and the separator.

[0095] More specifically, the fiber optic lens is located directly below the circular lens-shaped explosion-proof valve. The two-in-one fiber optic bundle serves as the connection structure between the fiber optic sensing structure and the fiber optic lens, realizing the function of beam splitting and beam combining within the fiber. In addition, the battery cell includes an upper cover, which includes a cover plate, an array of vents, and a quartz sleeve, etc. The sensing fibers located between the positive electrode and the diaphragm, and between the negative electrode and the diaphragm, can be processed into a two-in-one fiber optic bundle by parallel connection, and then the two-in-one fiber optic lens is formed by grinding the fiber end faces.

[0096] Next, the two fiber optic sensing structures fixed in the positive / negative electrodes and the diaphragm, along with the two-in-one fiber optic lens, are perfectly fitted and assembled with the explosion-proof valve on the top cover of the battery cell through a quartz sleeve, achieving optical path coupling and protection of the sensing fiber, fiber optic lens, and circular lens. During this process, electrolyte can be injected into the battery cell, utilizing a hydrodynamic centering force mechanism to give the fiber optic cable a stable self-aligning characteristic, thus stabilizing the fiber optic lens and the quartz sleeve, and aligning the optical axis.

[0097] More specifically, in this embodiment, the reason for adopting a conical fiber optic lens structure design is to utilize the unique mode field expansion, geometric focusing, and angle tolerance characteristics of conical lens fibers to significantly improve the tolerance for lateral, longitudinal, and angular deviations, making it easier to achieve spatial light transmission.

[0098] It should be noted that sensing optical fibers are formed based on the relationship between changes in light wavelength and changes in temperature, deformation, and pressure caused by changes in external conditions. Sensing optical fibers are characterized by their small size, high temperature resistance, corrosion resistance, and intrinsic insulation. Furthermore, since they use light waves for transmission, they are unaffected by external electromagnetic interference. Therefore, as a passive sensor, sensing optical fibers, with their optical path structure of sensing optical fibers, fiber optic lenses, and circular lenses, can simultaneously achieve spatial wireless transmission of optical signals, making them an ideal embedded sensing solution, even in harsh environments such as confined spaces and chemical corrosion within the battery cell.

[0099] More specifically, wavelength division multiplexing (WDM) technology can be used to achieve multi-physical monitoring and cross-decoupling by connecting multiple types and quantities of fiber optic sensing structures (not limited to fiber optic gratings or other fiber optic sensing units) in series on a fiber optic lens.

[0100] It should be noted that the above-mentioned battery cell only has a built-in sensing unit and does not have direct monitoring function. When it is necessary to measure the internal state of the battery cell, after the external controller outputs an optical signal, the battery cell can reflect a beam of light carrying the internal state information of the battery cell to realize internal state perception.

[0101] Example 2

[0102] Based on Embodiment 1, this embodiment provides a battery pack structure based on wireless fiber optic sensing, which includes: multiple fiber optic sensing cells placed side by side, a battery management system (BMS), an SLD light source built into the BMS, and multiple beam splitters corresponding to the number of cells. The battery pack may also be designed with a lower housing, on which a glass window is provided.

[0103] More specifically, a single-light-diffuse (SLD) light source is placed on each side of the battery pack's BMS. For example, a beam splitting method can be used, with one SLD light source monitoring the status of the cells on both sides. Furthermore, the SLD light source is directly powered by the low-voltage section of the BMS, allowing the BMS to autonomously control whether to monitor the internal status of the cells.

[0104] More specifically, the beam splitter is achieved through multilayer dielectric thin film interference control to ensure wide band and high accuracy of reflection-to-transmission ratio with low loss, preferably achieving a beam split of 1:99 reflection.

[0105] Accordingly, the beam transmission path within the battery pack is as follows: The SLD light source built into the BMS emits a collimated beam, which, after passing through a beam splitter, forms two beams. One beam travels along the direction of the reflected beam, and the other travels along the direction of the transmitted beam. The reflected beam passes through the circular lens explosion-proof valve of the battery cell and enters the two-in-one fiber optic lens. After passing through the fiber optic sensing structure (fiber grating or other fiber optic sensing unit) between the positive / negative electrode and the separator, it reflects a beam carrying the internal status information of the battery cell. The reflected beam then passes through the next beam splitter to form two beams: one reflected and one transmitted. Through the glass window, the beam carrying the internal status information of the battery cell is transmitted from inside the battery cell to outside the battery pack, achieving wireless transmission.

[0106] Example 3

[0107] Based on Embodiment 2, this embodiment provides a built-in monitoring system based on wireless fiber optic sensing, which is used in new energy storage stations. The system incorporates a track-mounted inspection machine with built-in fiber optic sensing demodulation equipment.

[0108] More specifically, the inspection robot starts from the charging station, autonomously navigates along the inspection route to the first inspection point, aligns the signal receiver of the fiber optic sensing demodulation equipment with the glass window of the battery pack, identifies the beam carrying the internal status information of the battery cells, and then gradually moves to the inspection endpoint to complete the inspection of the first battery pack within the battery cluster; it then proceeds to the second battery pack and completes the inspection in sequence. Furthermore, the inspection robot can also incorporate an edge computing unit to perform real-time analysis of the collected data, identify anomalies and mark their locations, transmit the data to the back-end management platform, generate detailed monitoring reports, and, based on historical data and AI algorithms, predict potential faults and guide maintenance strategies, enabling a single inspection robot to inspect the entire energy storage station.

[0109] This mobile inspection robot solves the problem of blind spots in traditional fixed sensor monitoring. The battery pack with built-in wireless fiber optic sensing provides built-in cell status information, enabling early warning of thermal runaway in energy storage stations, avoiding major safety accidents, extending cell lifespan, reducing operation and maintenance costs, improving fault location accuracy, shortening repair time, supporting unattended operation, and improving operation and maintenance efficiency.

[0110] Example 4

[0111] Building upon Embodiment 2, this embodiment provides a built-in monitoring system based on wireless fiber optic sensing, applicable to new energy vehicles. It includes a wireless fiber optic sensing battery pack, a built-in SLD light source, a BMS, an ECU-GPU heterogeneous computing unit, and an onboard optical communication receiving system. Specifically, the battery cells with built-in wireless fiber optic sensing collect internal state information in real time. The onboard optical communication receiving system converts the optical signals into electrical signals, which are then distributed to the ECU / GPU unit via an optical switch matrix. The ECU / GPU unit directly processes the signals, reducing sensor module costs. The ECU analyzes the data in real time to determine if battery temperature, strain, etc., are within safe ranges, sending a control command (adjusting the charging current) to the BMS every 200ms. The GPU synchronously receives the raw data, runs a model trained on historical charging data, predicts the remaining battery life (SOH), and feeds back the prediction result to the ECU every 5s, predicting the risk of thermal runaway. Utilizing the state information built into each battery cell, high-precision fault location is achieved, enabling partial shutdown and avoiding the risk of thermal runaway.

[0112] In summary, the battery cell structure, battery pack structure, and built-in detection and monitoring system based on wireless fiber optic sensing proposed in this invention, while utilizing the insulation of the lens structure and the high anti-interference and stability of wireless signal transmission, further combine the advantages of built-in fiber optic sensing structure and wireless transmission. This enables independent high-precision detection of each battery cell. Compared with existing technologies, it has advantages such as high safety, high flexibility, and reusability. Therefore, it is of great significance for improving the service life and safety of battery cells, and has good practical value and application prospects.

[0113] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell based on wireless fiber optic sensing, the battery cell comprising a housing, a positive electrode, a negative electrode, a diaphragm, and an explosion-proof valve, wherein the positive electrode, the negative electrode, and the diaphragm are all located within the housing, characterized in that: The battery cell incorporates a fiber optic sensing module, which includes a first fiber optic sensing structure disposed between the positive electrode and the separator, and a second fiber optic sensing structure disposed between the negative electrode and the separator. The first and second fiber optic sensing structures are joined together by a two-in-one fiber, and the end face of the fiber is processed into a fiber optic lens, which is processed into a conical structure. Furthermore, there are multiple first and second fiber optic sensing structures, each installed in series, for real-time acquisition of data on the internal state of the battery cell, including temperature, deformation, and air pressure. The explosion-proof valve is mounted on the housing and is made in the form of a glass circular lens. It serves as a pressure relief device for the battery cell and also as a transmission medium for optical signals entering and exiting the battery cell, achieving optical path coupling with the fiber optic lens.

2. The cell of claim 1, wherein, The battery cell is also equipped with an upper cover, which includes an upper cover plate, a lower plastic layer, an air vent array, and a sleeve. The explosion-proof valve is installed between the upper cover plate and the lower plastic layer. The sleeve is located below the explosion-proof valve and is sleeved with the fiber optic lens. The air vent array is located around the sleeve and is aligned and connected to the sleeve and the explosion-proof valve with their central axes coinciding. The sleeve is used to protect and limit the fiber optic lens.

3. The battery cell as described in claim 2, characterized in that, The first and second fiber optic sensing structures are in the form of fiber optic gratings; and / or The fiber optic sensing module utilizes the electrolyte injected into the battery cell to achieve optical axis alignment and stability between the fiber optic lens and the sleeve.

4. A wireless fiber optic sensor based battery pack, characterized by, The battery pack includes a light source, a beam splitter, and multiple battery cells arranged side by side, wherein: Each of the battery cells is a battery cell as described in any one of claims 1 to 3; The number of beam splitters is multiple, and they are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the explosion-proof valve. The light source is used to provide uniform parallel collimated light for the multiple beam splitters, and the light enters the corresponding explosion-proof valve through reflection from each beam splitter, while it is transmitted to the next adjacent beam splitter through transmission from each beam splitter.

5. The battery pack of claim 4, wherein, The light source is built into the vicinity of the battery management system of the battery pack itself and is directly powered by the voltage system of the battery management system; and / or The battery pack is also equipped with a lower housing for supporting and installing all the battery cells, and has a transparent window to expose the explosion-proof valve of each battery cell and the fiber optic lens coupled to it in the optical path; in addition, the lower housing is a detachable and reusable independent structure, and there is no beam connection between it and the battery cells.

6. The battery pack of claim 5, wherein, The light source is a broadband light source with a spectral bandwidth of 400nm to 2000nm, and its output beam is parallel collimated light with a spot diameter of 0.1mm to 1mm; and / or The beam splitter's splitting ratio, i.e., the ratio of reflection to transmission, is limited, with the reflection ratio being less than 10% and the transmission ratio being greater than 90%.

7. A built-in monitoring system for an energy storage system, the system comprising an inspection robot, a light source, and a battery cluster integrated from one or more battery packs, characterized in that: Each battery pack includes a battery cell and a beam splitter, wherein each of the battery cells is a battery cell as described in any one of claims 1 to 3; The number of beam splitters is multiple, and they are arranged along the optical path direction to correspond to each of the battery cells. Each beam splitter is aligned with the optical axis of the explosion-proof valve, and the beam splitting ratio, that is, the reflection and transmission ratio, of each beam splitter is the same. The light source is used to provide uniform parallel collimated light for the multiple beam splitters, and the light enters the corresponding explosion-proof valve through the reflection of each beam splitter, and is transmitted to the next adjacent beam splitter through the transmission of each beam splitter. The inspection robot is placed on a track arranged around the battery cluster. It moves along a preset inspection route and has a built-in fiber optic demodulation device for receiving and analyzing optical information transmitted by each of the fiber optic sensing modules through the explosion-proof valve, which carries the internal status information of the battery cells.

8. The system of claim 7, wherein, Based on the received light information, the inspection robot makes a preliminary prediction of the remaining lifespan of the battery cells and diagnoses fault information, which is then transmitted to the cloud server to establish a battery cell-level information database for the entire energy storage system.

9. A built-in monitoring system for new energy vehicles, the system comprising a battery pack, an on-board optical communication unit, and an on-board processor, characterized in that: The battery pack is the battery pack as described in any one of claims 5 to 6; The vehicle-mounted optical communication unit is used to receive optical information transmitted by each of the optical fiber sensing modules through the explosion-proof valve, which carries the internal status information of the battery cell, and transmit it to the vehicle-mounted processor. The vehicle-mounted processor processes the data from the vehicle-mounted optical communication unit and obtains the real-time status of the battery cell.

10. The system of claim 9, wherein, The on-board processor performs data processing in a closed loop of perception-transmission-computation-decision-execution, and transmits the real-time status of the battery cell to the battery management system of the battery pack through the on-board optical communication unit, thereby realizing battery health management.

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