Thermal runaway alarm device

Abstract

This invention relates to the field of thermal runaway detection technology, and provides a thermal runaway alarm device for detecting the thermal runaway state of lithium batteries within a battery pack. The device includes a light source and at least one optical signal receiver. The receiver and light source are located in the same unobstructed space, avoiding direct light path from the light source. When aerosol particles are released in the early stages of thermal runaway, light undergoes diffuse reflection on the aerosol surface, causing the receiver, which avoids the direct light path, to detect a significant increase in the intensity of scattered light, triggering an alarm after signal processing. This achieves millisecond-level detection of the earliest aerosol characteristic products of thermal runaway (earlier than open flame and temperature rise), providing a critical time window for protective measures. Only the spatial layout of the light source and receiver needs optimization; complex gas paths or sampling systems are unnecessary, significantly reducing maintenance costs. This solution innovatively solves the industry pain points of high latency and high false alarm rate in traditional thermal runaway detection through optical principles, providing proactive protection for power battery safety.

Description

Technical Field

[0001] This utility model relates to the field of thermal runaway detection technology, and in particular to a thermal runaway alarm device. Background Technology

[0002] Lithium-ion batteries, as the core energy source for electric vehicles, are connected in series and parallel to form battery modules, which are then integrated into a complete power system to provide driving energy for the vehicle. However, under charging, discharging, or abnormal operating conditions, lithium-ion batteries are at risk of thermal runaway. This process is accompanied by a violent chain of exothermic reactions, which instantaneously generate high-temperature, high-pressure flammable gases and aerosol mixtures containing metal oxides.

[0003] High-temperature heat and flammable gases rapidly diffuse to adjacent battery modules, triggering a chain reaction of thermal runaway in adjacent cells, ultimately leading to the propagation of thermal runaway across the entire battery pack. During this process, the chemical reactions within the cells can continue for 1-3 hours, releasing heat 5-10 times the cell's own chemical energy. This can cause structural damage to the battery system and potentially trigger serious safety accidents such as vehicle fires or explosions. Therefore, for power battery systems, achieving millisecond-level early detection of thermal runaway and triggering warnings before it spreads is a key challenge in mitigating systemic safety risks. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to propose a thermal runaway alarm device that can detect the thermal runaway state of a battery.

[0005] To achieve the above and other related objectives, this utility model provides a thermal runaway alarm device for use in a battery pack. The thermal runaway alarm device includes:

[0006] light source;

[0007] An optical signal receiver is provided, wherein one optical signal receiver is provided.

[0008] In this configuration, at least one of the optical signal receivers is located in the same unobstructed space as the light source, and at least one of the optical signal receivers avoids the light path of the light source.

[0009] In an optional embodiment of this utility model, a darkroom is further included, wherein the light source and the light signal receiver are disposed outside the darkroom, and a through hole is provided on the darkroom, so that all the light emitted by the light source can pass through the through hole and enter the darkroom.

[0010] In an optional embodiment of this utility model, the darkroom has a spherical structure.

[0011] In one optional embodiment of this utility model, the inner wall of the darkroom has a black, uneven structure.

[0012] In an optional embodiment of the present invention, a first curved mirror and a second curved mirror are further included, wherein the second curved mirror is configured to reflect diffuse light from the environment to the optical signal receiver.

[0013] In an optional embodiment of this utility model, the first curved mirror constitutes the outer wall of the darkroom, and the through hole is formed on the first curved mirror.

[0014] In an optional embodiment of this utility model, the first curved mirror and the second curved mirror are symmetrically arranged.

[0015] In an optional embodiment of this utility model, the first curved mirror and the second curved mirror are parabolic mirrors, and the light source and the light signal receiver are respectively placed at the focal points of the first curved mirror and the second curved mirror.

[0016] In an optional embodiment of this utility model, the first curved mirror and the second curved mirror are concave mirrors, and the incident light rays are reflected parallel after being reflected by the first curved mirror and then by the second curved mirror.

[0017] In an optional embodiment of this utility model, the thermal runaway alarm device is integrated into the battery management system of the battery pack.

[0018] In an optional embodiment of this utility model, the thermal runaway alarm device is a plug-in structure, which is inserted into the battery pack.

[0019] The technical advantages of this invention are as follows: This invention captures changes in diffuse reflection light intensity of aerosols by using a light signal receiver that avoids the direct path of the light source, directly monitoring aerosols released in the early stages of lithium battery thermal runaway. Aerosols are an early characteristic product of thermal runaway (earlier than open flames and rapid temperature rises), and this design significantly advances the warning window, buying crucial time for proactive protective measures (such as cooling or power cut-off). The design of the light signal receiver avoiding the direct light path of the light source effectively avoids interference from ambient background light or direct light, ensuring that signal changes are caused only by aerosol scattering. Combined with the specific release patterns of aerosols during thermal runaway (such as specific particle size distribution and concentration gradients), this scheme can distinguish itself from ordinary dust interference, improving detection accuracy. Optical detection requires no chemical reaction or complex gas sampling process, achieving millisecond-level real-time response. The device only requires optimized spatial layout of the light source and receiver, eliminating the need for complex fluid channels or precision gas paths within the battery pack, reducing system complexity and maintenance costs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the optical path of the thermal runaway alarm device in one embodiment of the present invention in the absence of thermal runaway.

[0022] Figure 2 This is a schematic diagram of the optical path of the thermal runaway alarm device in a thermal runaway state according to one embodiment of the present invention.

[0023] Explanation of reference numerals in the attached diagram: 10, light source; 20, light signal receiver; 30, dark chamber; 31, through hole; 40, first curved mirror; 50, second curved mirror. Detailed Implementation

[0024] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0025] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0026] With the rapid development of electric vehicles, lithium batteries, as their core energy supply system, bear the important responsibilities of providing power and extending driving range. Lithium batteries exhibit high energy density and good efficiency under charging, discharging, and high-load conditions, but they also pose certain safety risks. One of the most critical safety risks is thermal runaway, a violent and uncontrollable self-accelerating reaction process that occurs in lithium batteries under abnormal operating conditions. Thermal runaway not only damages the battery itself but can also trigger serious safety accidents such as vehicle fires and explosions, even threatening human lives.

[0027] Thermal runaway in lithium-ion batteries typically occurs when the electrochemical reactions within the battery or individual cells become uncontrolled. During this process, factors such as overcharging, over-discharging, short circuits, or external environmental factors cause a rapid rise in the battery's internal temperature, leading to a dramatic intensification of the internal chemical reactions. This further releases a large amount of heat, generating high-temperature, flammable gases (such as hydrogen (H), methane (CH), and carbon monoxide (CO),) and metal oxide aerosols. These gases and high-temperature heat rapidly diffuse to adjacent battery modules or cells, triggering a chain reaction that ultimately leads to the spread of thermal runaway throughout the entire battery pack. In this process, the battery's chemical reactions can continue for 1-3 hours, releasing heat that can reach 5-10 times the chemical energy of the individual cells, causing structural damage to the battery system and serious consequences such as vehicle fires or explosions.

[0028] Especially in electric vehicles, lithium battery systems often consist of multiple battery modules connected in series and parallel to form a large-capacity battery pack. Due to the high energy density and complex structural characteristics of batteries, thermal runaway not only severely damages individual battery modules but also triggers a chain reaction in adjacent cells through heat conduction and gas diffusion, causing the thermal runaway to spread throughout the entire battery pack. This chain reaction not only increases the damage to the battery system and vehicle structure but also poses a significant threat to the safety of the driver and passengers.

[0029] Currently, the main technologies for preventing thermal runaway include the monitoring and protection mechanisms of the Battery Management System (BMS). By monitoring key parameters such as internal battery temperature, voltage, and charge / discharge status in real time, the BMS can predict potential abnormalities to some extent, provide initial warnings, and implement relevant protective measures, such as automatic power-off, cooling, or isolation. However, these existing technologies often cannot achieve millisecond-level early detection and timely warning of thermal runaway. By the time the system detects an anomaly and responds, the earliest reaction window has often been missed, causing thermal runaway to spread throughout the entire battery pack.

[0030] Therefore, accurately detecting thermal runaway in its early stages and taking rapid preventative measures to avoid widespread catastrophic failure of the battery pack has become a key challenge for the safety of lithium-ion batteries in electric vehicles. To this end, researchers are dedicated to developing more accurate and sensitive thermal runaway detection technologies to achieve early detection within milliseconds, trigger timely warnings, and implement effective response strategies, thereby reducing the spread of thermal runaway and improving the overall safety of the battery system.

[0031] To solve the above-mentioned technical problems, this utility model provides a solution for achieving the above-mentioned objectives and other related objectives, such as... Figure 1-2As shown, this utility model provides a thermal runaway alarm device applied to a battery pack. The thermal runaway alarm device includes a light source 10 and a light signal receiver 20. At least one light signal receiver 20 is provided, and at least one light signal receiver 20 is located in the same unobstructed space as the light source 10, while at least one light signal receiver 20 avoids the light path of the light source 10.

[0032] This thermal runaway alarm device emits light into the internal space of the battery pack via a light source 10, and includes at least one optical signal receiver 20 that avoids the direct path of the light source 10. Under normal operating conditions, the receiver operates in a low-light-intensity environment due to this avoidance of the light path. When thermal runaway occurs in the lithium battery, the initially released aerosol particles (electrolyte decomposition products) diffuse within the space. Light irradiating the aerosol surface undergoes diffuse reflection, causing a significant increase in the intensity of scattered light detected by the receiver, which was originally avoiding the direct light path. This change in light intensity is converted into an electrical signal threshold fluctuation by the signal processing circuit, thereby triggering the alarm mechanism. Aerosol release precedes a sudden temperature rise and open flame; optical detection can trigger a response in the early stages of the thermal runaway chain reaction, buying crucial time for protective measures.

[0033] The optical path avoidance design prevents stray light and direct interference from the environment. Combined with the specific concentration gradient of aerosols during thermal runaway, it can effectively distinguish between ordinary dust and water mist, significantly reducing the false alarm rate. Optical detection requires no gas sampling or chemical reaction, achieving millisecond-level real-time monitoring. It only requires optimizing the spatial layout of the light source 10 and the receiver, simplifying the system structure and reducing maintenance costs. This device provides a more forward-looking and reliable thermal runaway protection node for power battery systems, solving the hysteresis defect of traditional detection methods that rely on a single parameter.

[0034] like Figure 1 , 2As shown, a single optical signal receiver 20 is provided. This receiver and the light source 10 are located in the same unobstructed space within the battery pack, and the receiver strictly avoids the direct light path of the light source 10. In operation, the light source 10 continuously emits a light beam (such as infrared or visible light), and the receiver, by avoiding the direct light path, is in a low background light intensity environment. If the battery experiences thermal runaway, the released aerosol particles (micron-sized suspended particles formed by electrolyte decomposition) diffuse into the light field region. The light undergoes multi-angle diffuse reflection on the aerosol surface, and some of the scattered light is captured by the receiver, which was originally avoiding the direct light, resulting in a significant increase in the receiver's light intensity signal. After processing by photoelectric conversion and threshold comparison circuitry, the optical signal is directly output as an alarm command. The coordinated layout of a single receiver and light source 10 reduces circuit complexity and assembly costs, making it particularly suitable for small battery packs with limited space. The design of avoiding the light path ensures minimal background light interference, and changes in the intensity of aerosol-induced scattered light can still be detected with a high signal-to-noise ratio. The reduction in the number of components simultaneously reduces the failure rate and the difficulty of later maintenance, improving the overall robustness of the system. This design verifies the feasibility of aerosol optical detection solutions in resource optimization scenarios, providing flexible configuration options for battery packs of different specifications.

[0035] In an optional embodiment of this invention, a darkroom 30 is further included. The light source 10 and the optical signal receiver 20 are disposed outside the darkroom 30. A through-hole 31 is provided on the darkroom 30, allowing all the light emitted by the light source 10 to pass through the through-hole 31 and enter the darkroom 30. This embodiment adds a sealed darkroom 30 outside the light source 10 and the optical signal receiver 20, with a through-hole 31 on the surface of the darkroom 30 to allow all the light from the light source 10 to enter. The interior of the darkroom 30 forms a fully isolated optical detection environment. The external light source 10 injects a directional beam into the darkroom 30 through the through-hole 31. The optical signal receiver 20 is also externally placed in the darkroom 30 to avoid direct light paths. The darkroom 30 physically isolates stray light, electromagnetic noise, and dust contamination within the battery pack, ensuring the purity of the aerosol scattering signal. External placement of the light source 10 and receiver avoids contact with high-temperature / corrosive gases during battery thermal runaway, improving the reliability of core components. The through-hole 31 constrains the beam path, making the light field distribution more concentrated and enhancing the effective capture efficiency of aerosol scattered light.

[0036] In an optional embodiment of this invention, the darkroom 30 has a spherical structure. The darkroom 30 is designed as a spherical closed cavity, with the through-hole 31 of the light source 10 located at a point on the spherical surface. After light enters, it forms an omnidirectional scattering field within the spherical space. The inner wall of the spherical cavity reflects the light multiple times randomly, creating a uniformly diffused light environment. The spherical structure achieves full-area light dispersion, eliminating detection blind spots, and ensuring that aerosols are fully irradiated and excited for scattering regardless of their location within the darkroom 30. Multiple reflections from the inner wall extend the optical path, allowing even small concentrations of aerosols to induce significant changes in light intensity, thus improving detection sensitivity. The spherical structure has no sharp angles, preventing particulate matter deposition caused by airflow vortices and maintaining the cleanliness inside the darkroom 30.

[0037] In an optional embodiment of this invention, the inner wall of the darkroom 30 has a black, uneven structure. A black light-absorbing material layer is constructed on the inner wall of the darkroom 30, and the surface is processed into an uneven textured structure. After light from the light source 10 enters, the inner wall efficiently absorbs the direct light, while the rough surface disrupts the specular reflection path. The black light-absorbing material eliminates reflected light from the inner wall to the greatest extent, so that the receiver is in a near-dark state when there is no aerosol. The uneven texture disperses residual reflected light into non-directional diffuse, avoiding the formation of a fixed reflected light path that interferes with the receiver. The extremely low background light environment multiplies the relative intensity of the aerosol scattering signal, and even a small change in concentration can trigger the alarm threshold.

[0038] In an optional embodiment of this invention, a first curved mirror 40 and a second curved mirror 50 are further included. The second curved mirror 50 is configured to reflect diffusely reflected light from the environment to the optical signal receiver 20. The addition of the second curved mirror 50 allows for the directional capture of diffusely reflected light from the environment and its reflection to the optical signal receiver 20. This mirror arrangement focuses and converges the originally dispersed aerosol scattered light, enhancing signal detectability. The curved mirror spatially converges the weak scattered light generated by low-concentration aerosols, overcoming the sensitivity limitations of traditional receivers. By extending the reflected light path, scattered light from battery dead zones far from the light source 10 can also be effectively collected, eliminating monitoring blind spots.

[0039] In an optional embodiment of this invention, the first curved mirror 40 constitutes the outer wall of the darkroom 30, and the through hole 31 is formed on the first curved mirror 40. The first curved mirror 40 serves as the main body of the darkroom 30 shell, and the through hole 31 of the light source 10 is directly formed on this mirror surface. Light enters the darkroom 30 after being controlled by the curved mirror, forming an optimized initial light field distribution. The curved mirror refracts the incident light from the light source 10 at a preset angle, preventing direct light from forming interference hotspots within the darkroom 30. The mirror body replaces the traditional metal wall of the darkroom 30, reducing overall weight and improving space utilization.

[0040] In an optional embodiment of this invention, the first curved mirror 40 and the second curved mirror 50 are symmetrically arranged. The symmetrical structure forms a collaborative channel for light emission and signal reception. The symmetrical mirrors constrain light rays to reflect multiple times within a predetermined area, increasing the probability of aerosol interaction. Light energy circulates within the mirror system, and even a small amount of aerosol can trigger significant changes in signal intensity.

[0041] In an optional embodiment of this invention, parabolic mirrors are used as the first curved mirror 40 and the second curved mirror 50, with the light source 10 and the light signal receiver 20 respectively positioned at the focal points of the first curved mirror 40 and the second curved mirror 50. The light emitted by the light source 10 is reflected by the first curved mirror 40 to form a parallel beam. The parabolic focal point characteristic parallelizes the beam, significantly improving the uniformity of aerosol irradiation. The second parabolic mirror precisely focuses the parallel scattered light onto the receiver at the focal point, achieving near-zero loss light energy capture.

[0042] In an optional embodiment of this invention, the first curved mirror 40 and the second curved mirror 50 are concave mirrors. Incident light reflected by the first curved mirror 40 and then reflected again by the second curved mirror 50 results in parallel reflected light. Using concave mirrors as curved mirrors, the first curved mirror 40 reflects the incident light to the second curved mirror 50, and after a second reflection, parallel light is output. The light source 10 and the receiver are located at the beginning and end points of the reflection path. The second reflection forms a parallel beam with a constant path, resisting signal fluctuations caused by vibration or deformation. Parallel light exhibits low transmission attenuation in the large-scale space of the battery pack, making it suitable for battery pack layouts with large module spacing.

[0043] In an optional embodiment of this invention, the optical signal receiver 20 is a photodiode or a phototransistor. The optical signal receiver 20 uses a photodiode or phototransistor to convert changes in light intensity into an electrical signal output. The semiconductor optoelectronic element achieves high-speed photo-to-electrical conversion, meeting the millisecond-level early warning requirements for thermal runaway. The phototransistor has adjustable gain, making it compatible with complex lighting environments within the battery pack.

[0044] In an optional embodiment of this invention, the light source 10 is an infrared laser that emits a coherent beam with a wavelength in the invisible light band (e.g., 780nm-1550nm). Infrared wavelengths have high aerosol scattering efficiency and are not easily absorbed by electrolyte vapors. By avoiding common visible light bands in operating conditions (e.g., vehicle headlights, sunlight), the false alarm rate approaches zero. The invisible light avoids visual pollution and meets the safety standards for automotive optical equipment.

[0045] In an optional embodiment of this invention, the thermal runaway alarm device is integrated into the battery management system (BMS), with the alarm signal directly connected to the control core. The trigger signal can directly drive active protection mechanisms such as cooling, power-off, and pressure relief. Combined with cross-verification using multiple parameters such as voltage and temperature, the alarm confidence level is improved.

[0046] In an optional embodiment of this invention, the alarm device is designed as a standard plug-in structure, directly inserted into the pre-reserved slot in the battery pack via a waterproof interface. The modular design supports quick replacement without disassembling the pack, reducing maintenance costs. The plug-in features IP67 protection to prevent electrolyte corrosion of precision optical components within the battery pack. Its plug-and-play characteristic is compatible with automated battery pack production lines.

[0047] This utility model also proposes a thermal runaway alarm method, applied to the aforementioned thermal runaway alarm device, comprising:

[0048] S1. Control the light source 10 to emit light and acquire the light intensity at the light signal receiver 20. Control the light source 10 (such as an infrared laser) to continuously emit a light beam into the internal space of the battery pack, while simultaneously acquiring the light intensity signal of the light signal receiver 20 (such as a second receiver 22) that avoids the light path. The light source 10 uses pulse modulation or constant current drive to ensure stable emitted light intensity. The receiver converts the light signal into a voltage quantity through a photoelectric conversion circuit (such as an operational amplifier integrator), which is then sampled by an ADC and transmitted to the processor.

[0049] S2. Determine if thermal runaway exists based on the light intensity. When the light intensity of the receiver in the avoidance light path continuously increases and the increase exceeds a preset threshold range, it is determined to be a thermal runaway event. Record the background light intensity in an aerosol-free environment as a benchmark during system initialization. Determine if the signal amplification meets the slope requirement (e.g., continuous rise rate). Exclude transient interference (e.g., circuit noise) requiring a continuous exceedance time to reach a set threshold. If a dual-receiver scheme is used, synchronously monitor the signal attenuation of the receiver in the direct light path (e.g., the first receiver 21) to form differential cross-verification. Fuse temperature sensor data (e.g., cell temperature provided by the BMS) to cross-verify non-optical interference.

[0050] In summary, the optical path avoidance design achieves highly sensitive detection and accurate early warning of early aerosol release, significantly improving the safety and reliability of power battery thermal runaway protection. Utilizing the characteristic that aerosols are the earliest product of thermal runaway, the optical signal receiver 20 captures the enhanced scattered light signal by avoiding the direct path of the light source 10, identifying risks tens of seconds to minutes earlier than traditional temperature / voltage detection, thus gaining a critical time window for active protection. The avoidance optical path, combined with the selection of infrared laser bands (e.g., 780–1550nm), effectively avoids interference from ambient stray light and electrolyte vapor. Simultaneously, the photodiode / transistor's ability to identify the specific scattering of aerosols fundamentally eliminates the possibility of false triggering by ordinary dust or water mist. Optical detection requires no chemical reaction or gas sampling; the pulse modulation of the light source 10 and the high-speed photoelectric conversion of the receiver work together to achieve millisecond-level signal capture, and the active protection mechanisms such as cooling, power-off, and pressure relief are directly driven through BMS system integration. The modular design of the connectors (IP67 protection) supports plug-and-play and maintenance-free operation. While ensuring corrosion resistance and high temperature resistance, it matches the needs of automated production lines and significantly reduces the total life cycle maintenance cost.

[0051] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0052] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0053] Throughout this specification, references to "an embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the present invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0054] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0055] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0056] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0057] The above description of the embodiments shown in this utility model (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the utility model to the precise forms disclosed herein. Although specific embodiments and examples of the utility model have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the utility model, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the utility model in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the utility model.

[0058] This document has generally described the systems and methods in detail to aid in understanding the present invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention can be practiced without one or more specific details, or using other devices, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0059] Therefore, although the present invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the above disclosure, and it should be understood that in some cases, certain features of the present invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the present invention. The present invention is not intended to be limited to the specific terms used in the following claims and / or the specific embodiments disclosed as the best mode of carrying out the present invention, but the present invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the present invention will be determined only by the appended claims.

Claims

1. A thermal runaway alarm device, characterized in that, The thermal runaway alarm device, applied to a battery pack, includes: light source; An optical signal receiver is provided; In this configuration, at least one of the optical signal receivers is located in the same unobstructed space as the light source, and at least one of the optical signal receivers avoids the light path of the light source.

2. A thermal runaway warning device according to claim 1, wherein, It also includes a darkroom, with the light source and the light signal receiver located outside the darkroom. The darkroom has a through hole, allowing all the light emitted by the light source to pass through the through hole and enter the darkroom.

3. A thermal runaway warning device according to claim 2, wherein, The darkroom has a spherical structure.

4. The thermal runaway warning device of claim 2, wherein, The inner wall of the darkroom has a black, uneven structure.

5. The thermal runaway warning device of claim 2, wherein, It also includes a first curved mirror and a second curved mirror, the second curved mirror being configured to reflect diffuse light from the environment to the optical signal receiver.

6. A thermal runaway warning device according to claim 5, wherein, The first curved mirror forms the outer wall of the darkroom, and the through hole is formed on the first curved mirror.

7. A thermal runaway warning device according to claim 5, wherein, The first curved mirror and the second curved mirror are arranged symmetrically.

8. The thermal runaway warning device of claim 5, wherein, The first curved mirror and the second curved mirror are parabolic mirrors, and the light source and the light signal receiver are respectively placed at the focal points of the first curved mirror and the second curved mirror.

9. The thermal runaway warning device of claim 5, wherein, The first curved mirror and the second curved mirror are concave mirrors. The incident light rays are reflected by the first curved mirror and then reflected again by the second curved mirror, and the reflected light rays are parallel.

10. The thermal runaway warning device of claim 1, wherein, The thermal runaway alarm device is integrated into the battery management system of the battery pack or The thermal runaway alarm device is a plug-in structure, which is inserted into the battery pack.

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