Flame detection system and method for manufacturing sensors embedded in carbon nanotube-based battery enclosure

Abstract

The present invention relates to a CNT-based flame and temperature sensing system for detecting battery fires and temperature anomalies, and more specifically, to a technology that prevents fire risks in advance by detecting and analyzing temperature changes inside a battery in real time. The present invention utilizes a composite sensor composed of carbon nanotubes (CNT) and polyurethane (PU) to respond sensitively to temperature changes and accurately detect abnormal conditions inside the battery. The system according to the present invention consists of a sensing unit, a measuring unit, an analysis unit, a warning signal generation unit, and a power control unit. Each component operates integrally to monitor the battery status in real time, detect abnormal conditions early, and automatically perform preventive measures such as power cutoff. The system evaluates the battery status based on the rate of change of sensor resistance at set threshold values, such as 60°C and 80°C, and eliminates fire risks by transmitting a warning signal and cutting off the battery power upon the occurrence of an anomaly. The present invention is applicable to various battery application fields, such as electric vehicles, energy storage systems (ESS), and smart grids, and can maximize the reliability and safety of the battery by utilizing the high sensitivity and high precision characteristics of the CNT-based composite. This system predicts the likelihood of fire in real time through automated data analysis and control, contributing to significantly improving the durability and safety of batteries.

Description

Technology Field

[0001] The present invention relates to a system for detecting fire and temperature abnormalities in a battery in real time, and more specifically, to a technology for preventing fire risks in advance by embedding a carbon nanotube-based composite sensor in a battery enclosure to detect temperature changes and flame occurrences, and analyzing and controlling them. Background Technology

[0002] With the rapid increase in the use of high-density energy storage systems, such as lithium-ion batteries, in energy storage systems (ESS), electric vehicles (EVs), and electronic devices, the importance of battery safety management technology is becoming increasingly prominent. Against this backdrop, the development of technologies to detect and respond to internal battery fires and temperature abnormalities in real time has established itself as a major research field.

[0003] Existing battery management systems (BMS) focus on monitoring key data such as battery voltage, current, and temperature to prevent battery overcharging and over-discharging, but they have limitations in detecting sudden abnormal conditions such as fire early on or responding sensitively to minute temperature changes inside the battery.

[0004] Technology capable of precisely detecting the internal state of a battery using high-sensitivity sensors is attracting attention; in particular, composite sensors utilizing nanomaterials such as carbon nanotubes (CNT) are gaining importance as they respond sensitively to temperature changes and can be designed in a form suitable for the battery's internal structure.

[0005] These technologies enable real-time data monitoring and analysis in conjunction with the Internet of Things (IoT), and enhance safety by combining with automated control systems, such as sending warning signals and cutting off power in the event of a fire. In addition, research is underway to develop sensors suitable for mass production by utilizing high-precision manufacturing technologies such as screen printing.

[0006] Existing battery fire detection systems have several problems.

[0007] Existing technology only reacts after a battery fire has progressed and external changes become evident, failing to detect subtle abnormal conditions in the early stages and making fire prevention and initial response difficult.

[0008] In addition, commonly used sensor technology has low sensitivity to temperature changes and cannot accurately detect minute temperature increases or abnormal conditions inside the battery.

[0009] Furthermore, the narrow and complex internal structure of the battery imposes significant physical constraints on the placement of conventional sensors, and since they often fail to operate reliably under various environmental conditions, ensuring reliability and durability is difficult.

[0010] Furthermore, existing flame detection sensors and systems face difficulties in securing commercial competitiveness due to complex manufacturing processes or high costs, and there are limitations in terms of mass production and economic feasibility as sensors often need to be designed to fit the battery structure.

[0011] Currently commercialized technology is not fully integrated with IoT-based real-time data analysis systems and automated control systems, so even if the possibility of a fire is detected, preventive measures such as rapidly cutting off power or sending warning signals cannot be taken.

[0012] Furthermore, if the accuracy of data collected from within the battery is low or contains noise, it may misdiagnose abnormal conditions or fail to emit warning signals, thereby threatening battery safety.

[0013] These issues degrade the reliability and efficiency of existing battery fire detection technologies, acting as a major factor in lowering the completeness of fire prevention and response systems. To address this, the development of innovative technologies is required that provide more precise and sensitive sensor technology, high-efficiency manufacturing processes, and seamless integration with the IoT. Prior art literature

[0014] Japanese Published Patent No. 2024-159761 "System and method for diagnosing abnormal temperature conditions of a battery cell using a temperature sensor of a battery management system (BMS)" Korean Registered Patent No. 10-2713371 "Real-time monitoring system for electric vehicle battery using a fiber optic temperature sensor" Korean Published Patent No. 10-2024-0101054 "Temperature sensor integrated battery module" The problem to be solved

[0015] The present invention aims to prevent fire hazards in advance by detecting minute temperature changes and initial fire signs inside a battery in real time.

[0016] The present invention aims to utilize a carbon nanotube (CNT)-based composite sensor to respond sensitively to a rise in temperature inside a battery and to precisely measure data.

[0017] The present invention aims to economically produce a thin and flexible sensor suitable for a battery structure through a screen printing technique, making it suitable for mass production.

[0018] The present invention aims to monitor battery status in real time in conjunction with IoT and AI-based data analysis technologies, immediately determine the possibility of fire occurrence, and automatically send a warning signal.

[0019] The present invention aims to analyze the possibility of fire caused by a rapid temperature rise inside the battery and to enhance battery safety by cutting off the power supply. means of solving the problem

[0020] A battery flame detection system according to one embodiment may include a sensing unit disposed inside the battery and comprising a carbon nanotube composite whose electrical resistance changes according to temperature change, and a measuring unit that measures resistance information detected from the sensing unit in real time.

[0021] The sensing part according to one embodiment is a carbon nanotube composite fabricated using a screen printing technique and can be placed in the void space inside the battery.

[0022] According to one embodiment, the measuring unit may include a warning signal generating unit that analyzes the measured resistance information and generates a warning signal when the internal temperature of the battery exceeds a selected threshold.

[0023] According to one embodiment, the warning signal generating unit may be connected to a power control unit that cuts off battery power by linking the generated warning signal with an IoT network.

[0024] According to one embodiment, the measuring unit may further include an analysis unit that calculates the rate of change in temperature inside the battery and predicts the possibility of an initial fire.

[0025] The sensing unit according to one embodiment has a structure in which a carbon nanotube composite and an insulating layer are combined, and can be configured to detect temperature and flame changes more precisely by minimizing external interference.

[0026] A method for manufacturing a carbon nanotube-based sensor according to one embodiment may include the steps of: preparing a composite ink by mixing carbon nanotubes and polyurethane; transferring the composite ink onto an insulating substrate in a desired pattern using a screen printing technique; drying and curing the transferred composite ink to form a sensor; and configuring the formed sensor to detect temperature and flame changes by placing it inside a battery enclosure.

[0027] The step of preparing the composite ink according to one embodiment may include the step of optimizing electrical sensitivity by mixing carbon nanotubes into a polyurethane matrix at 1.5 wt%.

[0028] The screen printing technique according to one embodiment can be performed by transferring composite ink with a thickness of 0.1 mm, and designing the transferred pattern in a form that is continuously partitioned with a central round area and on both sides thereof.

[0029] The step of placing a sensor inside the battery enclosure according to one embodiment can be designed such that a sensor formed on a PET film is placed in the gap space between battery modules, so that when the temperature reaches 60°C, the resistance is reduced by at least 80%, and when the temperature reaches 80°C, the resistance is reduced by at least 100%. Effects of the invention

[0030] According to one embodiment, safety can be significantly improved by detecting minute temperature changes and signs of flame occurring inside the battery in real time.

[0031] According to one embodiment, the internal state of a battery can be precisely monitored through the high sensitivity of a CNT-based composite sensor.

[0032] According to one embodiment, an economical and mass-producible sensor can be manufactured using a screen printing technique.

[0033] According to one embodiment, the battery status can be continuously monitored through a system linked to IoT, and immediate warning and power cutoff can be performed in the event of abnormal signs.

[0034] According to one embodiment, the risk of battery fire can be predicted in advance and preventive measures can be automatically executed through an AI-based analysis system. Brief explanation of the drawing

[0035] FIG. 1 is a drawing illustrating a battery flame detection system according to one embodiment. Figure 2 is a diagram illustrating a method for manufacturing a sensor using a screen printing technique, which is a sensor used in a battery flame detection system. Figure 3 is a drawing explaining the specifications of a manufactured single sensor. Figure 4 is a diagram illustrating a fabricated multi-sensor. Figures 5a, 5b, and 5c are diagrams illustrating the electrical behavior of the sensor. Figure 6 is a diagram illustrating the operation method of a flame / temperature detection system using an electrical data measurement system. FIG. 7 is a diagram that more specifically explains the analysis and power control method according to one embodiment. Specific details for implementing the invention

[0036] Specific structural or functional descriptions of embodiments according to the concept of the present invention disclosed herein are provided merely for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms and are not limited to the embodiments described herein.

[0037] Embodiments according to the concept of the present invention may be subject to various modifications and may take various forms; therefore, embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosed forms, and includes modifications, equivalents, or substitutions that fall within the spirit and scope of the present invention.

[0038] Terms such as "first" or "second" may be used to describe various components, but said components should not be limited by said terms. For the sole purpose of distinguishing one component from another, for example, without departing from the scope of rights according to the concept of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0039] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions describing the relationships between components, such as "between," "exactly between," or "directly adjacent to," should be interpreted in the same way.

[0040] The terms used herein are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0041] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0043] Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, the scope of the patent application is not limited or restricted by these embodiments. Identical reference numerals in each drawing indicate identical components.

[0044] FIG. 1 is a drawing illustrating a battery flame detection system (100) according to one embodiment.

[0045] A battery flame detection system (100) according to one embodiment detects flames and temperature changes that may occur inside the battery in real time, analyzes them, and generates a warning signal, thereby improving the safety of the battery.

[0046] The battery flame detection system (100) includes a sensing unit (110), a measuring unit (120), a warning signal generating unit (130), and an analysis unit (140), and each component can monitor the internal state of the battery and maintain safety.

[0047] The sensing unit (110) is placed inside the battery and includes a carbon nanotube composite whose electrical resistance changes according to temperature change.

[0048] The sensing unit (110) is placed in the void space inside the battery to detect temperature changes and flame changes occurring inside the battery in real time.

[0049] This gap space corresponds to the empty space between battery modules, and the sensing unit (110) can be applied to batteries of various shapes and sizes regardless of the battery structure.

[0050] The sensing part (110) includes a carbon nanotube composite, which may be composed of 1.5 weight% carbon nanotubes (CNT) and a polyurethane (PU) matrix.

[0051] Carbon nanotubes have the characteristic that their electrical resistance changes with temperature changes, and this characteristic is used to detect temperature and flame changes inside the battery. The sensing unit (110) is manufactured using a screen printing technique, and the composite ink is transferred onto an insulating substrate. The screen printing technique is designed to transfer the composite ink thinly and precisely to a thickness of 0.1 mm, which enables the sensing unit (110) to effectively detect minute temperature changes inside the battery.

[0052] The specific numerical values ​​described in this invention are merely specific examples and are not limited thereto. That is, each numerical value can be optimally modified in various ways.

[0053] The sensing unit (110) has a structure combined with an insulating layer so that the transferred composite ink can minimize external interference, thereby enabling more precise and stable detection of temperature and flame changes. The sensing unit (110) can be designed so that when the internal temperature of the battery reaches 60°C, the resistance decreases by at least 80%, and when the temperature reaches 80°C, the resistance decreases by at least 100%.

[0054] This change in resistance enables the sensing unit (110) to accurately detect a rapid temperature rise or fire inside the battery.

[0055] The measuring unit (120) measures resistance information detected from the sensing unit (110) in real time. The measuring unit (120) measures electrical resistance data transmitted from the sensing unit (110) in real time and precisely analyzes the temperature change inside the battery based on this.

[0056] The measuring unit (120) uses temperature change data inside the battery to determine whether it exceeds a set threshold (e.g., 60°C or 80°C).

[0057] Data on temperature change inside the battery is transmitted to the warning signal generation unit (130) so that additional safety measures can be taken.

[0058] The measurement unit (120) calculates the rate of temperature change to predict the possibility of an initial fire occurring inside the battery. The data provided by the measurement unit (120) is further evaluated by the analysis unit (140). The measurement unit (120) continuously transmits the collected data to the warning signal generation unit (130) and the analysis unit (140) so that the condition inside the battery can be monitored in real time.

[0059] The warning signal generation unit (130) analyzes the data received from the measurement unit (120) and generates a warning signal when the internal temperature of the battery exceeds a set threshold.

[0060] For example, the warning signal generating unit (130) generates a warning signal when the internal temperature of the battery reaches 60°C and the resistance of the sensing unit (110) decreases by 80%.

[0061] The warning signal generation unit (130) links the generated warning signal with an IoT network and can be connected to a power control unit that cuts off battery power. The warning signal generation unit (130) transmits the warning signal to an AI-based data analysis system to support real-time evaluation of the battery status and to enable additional safety measures.

[0062] The warning signal generating unit (130) warns of the possibility of a battery fire in advance, thereby playing an important role in enhancing the safety of the battery.

[0063] The analysis unit (140) performs the function of predicting the possibility of an initial fire by calculating the rate of change in the internal temperature of the battery. The analysis unit (140) calculates the rate of change in temperature based on data transmitted from the measurement unit (120).

[0064] The analysis unit (140) can analyze the pattern of change in the internal temperature of the battery in real time and diagnose the possibility of an initial fire early.

[0065] The analysis unit (140) evaluates collected data using AI-based data analysis technology and continuously monitors the battery status. When the critical temperature inside the battery is exceeded, the analysis unit (140) transmits an appropriate warning signal to the warning signal generation unit (130), thereby enabling the maintenance of the battery's safety. The analysis unit (140) evaluates the possibility of fire occurrence in real time and plays a key role in supporting preventive measures based on this.

[0066] The battery flame detection system (100) utilizes a carbon nanotube composite to detect temperature changes and flames occurring inside the battery in real time, generates a warning signal based on this, and can improve battery safety by linking with an IoT network.

[0067] The battery flame detection system (100) overcomes the limitations of reaction speed and accuracy of existing flame detection systems and can sensitively detect minute temperature changes inside the battery. The battery flame detection system (100) can be easily integrated into various battery structures through screen printing techniques and can be utilized in various applications such as electric vehicles, smartphones, and laptops. The battery flame detection system (100) detects the possibility of an initial fire early and provides a warning signal, and minimizes the risk of fire through preventive measures such as cutting off the battery power.

[0068] Figure 2 is a drawing (200) illustrating a method of manufacturing a sensor using a screen printing technique, which is a sensor used in a battery flame detection system.

[0069] The sensor is fabricated using a composite ink composed of carbon nanotubes (CNT) and polyurethane (PU), and can detect flames and temperature changes occurring inside the battery in real time.

[0070] According to the sensor fabrication method, a composite ink can be manufactured using a polyurethane matrix containing 1.5 wt% of CNTs.

[0071] CNTs have the characteristic of changing electrical resistance with temperature variations, enabling precise detection of temperature changes inside the battery.

[0072] According to the sensor fabrication method, CNT and PU are uniformly mixed to control the viscosity of the composite ink, and the viscosity is set to be suitable for the screen printing technique.

[0073] According to the sensor fabrication method, a mixed CNT / PU composite ink is loaded onto a printing screen. During this process, the ink is distributed evenly across the entire screen area to ensure consistency in pattern transfer. According to the sensor fabrication method, the distribution of the CNT / PU ink is closely monitored and carefully managed to ensure that the ink does not overflow or run out.

[0074] According to the sensor fabrication method, a squeegee is moved over the screen at a constant angle and pressure to accurately transfer CNT / PU composite ink onto the substrate according to the screen pattern. According to the sensor fabrication method, the movement speed of the squeegee is maintained constant to ensure that the ink is uniformly distributed across all parts of the pattern.

[0075] This process is essential to ensure the structural stability and electrical performance of the sensor. The transferred pattern consists of a rounded area in the center and partitioned sections on both sides, which is precisely formed to a thickness of 0.1 mm. This thickness provides optimal conditions for the sensor to respond sensitively to temperature changes and flames. According to the sensor fabrication method, squeegee pressure is adjusted to prevent ink from overflowing outside the pattern and to carefully control the transfer so that irregular transfer does not occur.

[0076] After completing the squeegee operation, the condition of the transferred ink can be checked to verify whether the accuracy and quality of the screen pattern have been maintained.

[0077] According to the sensor manufacturing method, after the squeegee operation is completed, the stencil used with the screen is carefully removed.

[0078] The stencil serves to protect against ink penetration into unnecessary areas during the transfer process. According to the sensor fabrication method, after removing the stencil, it is verified whether the transferred CNT / PU composite ink has formed an accurately designed pattern.

[0079] This pattern is a key factor in determining the electrical characteristics and temperature sensing performance of the sensor. According to the sensor fabrication method, the composite ink is stabilized by drying and curing the formed pattern.

[0080] The curing process enhances the durability of the sensor and enables it to withstand long-term use inside a battery. According to the sensor manufacturing method, quality inspections are performed to verify that the cured pattern is uniform and defect-free, and to ensure that the sensor exhibits appropriate changes in electrical resistance in response to temperature variations.

[0081] The fabricated sensor has a structure combining a CNT composite and an insulating layer, and can precisely detect temperature and flame changes inside the battery by minimizing external interference.

[0082] The sensor is placed in the gap space between battery modules and can be flexibly applied to various battery structures and sizes.

[0083] For example, the sensor can be designed so that when the temperature reaches 60°C, the resistance decreases by at least 80%, and when the temperature reaches 80°C, the resistance decreases by at least 100%.

[0084] These changes in resistance enable the sensor to detect rapid temperature increases or fires in real time. The sensor, fabricated using screen printing techniques, implements a precise pattern with a thickness of 0.1 mm, which maximizes sensor sensitivity and is suitable for mass production.

[0085] Screen printing is a manufacturing method that enables the inexpensive and efficient transfer of CNT / PU composite inks, significantly improving productivity compared to conventional methods. This technique allows for the creation of patterns of various shapes and sizes, enabling designs tailored to battery structures. The stencils used in the screen printing process are reusable, contributing to reduced production costs and an environmentally friendly manufacturing process.

[0086] The fabricated sensor can be integrated into various battery applications, such as electric vehicles, smartphones, and laptops, and can enhance safety within the battery.

[0087] The present invention provides a method for efficiently and precisely fabricating a sensor utilizing a CNT-based composite through a screen printing technique. The fabricated sensor has several advantages, such as precise pattern implementation, minimized external interference, and suitability for mass production, and can improve battery safety by detecting temperature changes and flames inside the battery in real time.

[0088] FIG. 3 is a detailed drawing (300) showing the specifications and structure of a single sensor used in a battery flame detection system according to one embodiment of the present invention.

[0089] The sensor consists of a carbon nanotube (CNT) and polyurethane (PU) composite, a PET film, and silver paint. Precisely fabricated using a screen printing technique, this sensor is designed to detect flames and temperature changes that may occur inside the battery in real time.

[0090] The fabricated sensor uses a PET film as a substrate, and this film serves as a structural support for the sensor. The PET film is thin, flexible, and highly durable, making it suitable for the narrow void spaces inside the battery. A composite sensor composed of carbon nanotubes (CNT) and polyurethane (PU) is formed on the PET film.

[0091] The CNT composite sensor has a shape with a round sensing area in the center and rectangular patterns continuously arranged on both sides.

[0092] The diameter of the central round detection area is designed to be 5mm, and the lengths of the rectangular patterns on both sides are also identical at 5mm. This design reflects structural optimization for efficiently detecting temperature changes and flames and reliably transmitting electrical signals. The sensor is manufactured with a thickness of 0.1mm, which is the result of a precise pattern implemented through screen printing techniques. This thickness allows the sensor to be effectively installed even in the narrow space inside a battery and maximizes the sensitivity required for detecting temperature changes and flames.

[0093] The silver-painted electrodes at both ends of the sensor serve to transmit changes in electrical resistance due to temperature variations to an external measuring device through an electrical connection with the CNT composite. As electrodes, the silver paint provides high conductivity and stability, acting as a critical factor in maintaining the sensor's detection performance.

[0094] The electrode is designed to be perfectly bonded to the CNT composite during the screen printing process, thereby increasing signal transmission efficiency. The sensor's CNT composite is a composite composed of CNT and PU, containing 1.5 wt% of CNT. CNT exhibits a characteristic where resistance changes sensitively with temperature variations, while PU acts as a matrix to uniformly disperse the CNT. This configuration was designed to optimize electrical sensitivity to temperature changes.

[0095] The sensor is designed so that its resistance decreases by at least 80% when the temperature reaches 60°C and by at least 100% when it reaches 80°C. These electrical characteristics enable real-time detection of a rapid temperature rise or the occurrence of flames inside the battery.

[0096] The central rounded area of ​​the sensor performs the primary sensing function, while the rectangular patterns on both sides form electrical signal transmission paths to transmit sensing data to an external device. CNT-based composite sensors can be fabricated using screen printing techniques. This technique forms the sensor's sensing pattern by precisely transferring composite ink onto a PET film. During the screen printing process, the composite ink is transferred to a thickness of exactly 0.1 mm, providing a uniform pattern and structural stability.

[0097] The stencil used in the screen printing process can clearly form a central rounded area and rectangular patterns on both sides. Through a squeegee operation, the composite ink is accurately transferred onto the PET film, and the final sensor is completed through stencil removal, drying, and curing processes. This process maximizes the pattern accuracy and detection performance of the sensor. The fabricated sensor is designed to be installed in the gap space between battery modules. This sensor can be flexibly applied regardless of the battery structure and size, and it prevents fire hazards in advance by detecting signs of thermal anomalies occurring inside the battery in real time. The sensor's structural design is suitable for the internal battery environment and can maintain stable performance.

[0098] Sensors can be applied to various battery-based devices, such as electric vehicles, smartphones, and laptops. In particular, the sensor's precise pattern structure and high sensitivity characteristics enhance the battery safety of these devices.

[0099] The sensor monitors the battery status in real time to detect abnormal signs early and provides data to the safety management system.

[0100] FIG. 4 is a drawing (400) that explains in detail the specifications and structure of a multi-sensor used in a battery flame detection system according to one embodiment of the present invention.

[0101] The multi-sensor is based on a carbon nanotube (CNT) and polyurethane (PU) composite and uses a PET film as a substrate.

[0102] The multi-sensor is designed to detect temperature and flame changes in real time over a wide area inside a large battery pack by configuring multiple single sensors into a network array.

[0103] The fabricated multi-sensor uses a PET film as a substrate, and the PET film serves to stably support the structure of the multi-sensor. The PET film is designed with a thickness of 0.1mm and is a thin, flexible, and highly durable material suitable for the void spaces inside the battery.

[0104] Multiple single sensors composed of CNT-based composites are arranged in a network form on a PET film. Each single sensor consists of a round sensing area and a rectangular pattern connecting them.

[0105] The sensing area sensitively detects temperature changes inside the battery, and the rectangular pattern forms an electrical path that transmits the detected data to the outside.

[0106] For example, the multi-sensor can be composed of network cells with a size of 50mm x 50mm, and each cell can be arranged at intervals of 25mm.

[0107] The entire multi-sensor array is designed with a size of 150mm x 200mm, allowing for simultaneous monitoring of a large area inside the battery pack. Each network cell operates independently yet functions integrally through the network, enabling real-time detection of temperature and flame changes.

[0108] The CNT composite, a component of the multi-sensor, consists of carbon nanotubes (CNT) and a polyurethane (PU) matrix. The CNTs are included at 1.5 wt% and exhibit a characteristic where electrical resistance changes sensitively with temperature variations. The PU serves to uniformly disperse the CNTs and provides the physical stability and durability of the sensor. The CNT composite sensor exhibits a characteristic where resistance decreases as the temperature rises, and the central sensing area of ​​the sensor is designed with a diameter of 5 mm. The lengths of the rectangular patterns can also be designed to be 5 mm each.

[0109] Each individual sensor of the multi-sensor system can be designed so that its resistance decreases by at least 80% when the temperature reaches 60°C and by at least 100% when it reaches 80°C. This characteristic enables real-time detection of rapid temperature increases or flame occurrences within the battery. Each individual sensor of the multi-sensor system includes electrodes composed of silver paint at both ends. The silver paint electrodes are electrically connected to the CNT composite and serve to transmit changes in resistance due to temperature variations to an external measuring device. The silver paint provides high conductivity and stability, and the connections between the electrodes are configured in a network form, allowing all individual sensors to transmit data integrally.

[0110] The fabricated multi-sensor can be designed to be installed in the void space inside the battery pack. The multi-sensor can be flexibly applied to batteries of various sizes and structures and can simultaneously monitor a wide area of ​​a large battery pack.

[0111] Figures 5a, 5b, and 5c are diagrams illustrating the electrical behavior of the sensor.

[0112] FIG. 5a is a detailed diagram (510) showing the relationship between the number of screen printings and electrical conductivity of a carbon nanotube (CNT)-based composite sensor according to the present invention.

[0113] In the present invention, changes in electrical conductivity are observed by repeatedly screen printing a CNT / PU composite ink onto a PET film. In the present invention, the number of screen printing cycles was varied from 1 to 10, and it was confirmed that as the number of printing cycles increased, the electrical conductivity gradually increased and then stabilized. In the present invention, it was observed that the conductivity stabilized when the number of screen printing cycles reached 7, which indicates that a sufficient CNT network was formed. In the present invention, it was confirmed that the CNT composite ink is uniformly distributed and connectivity between networks is strengthened during the screen printing process, thereby enabling the fabrication of a sensor with stable electrical characteristics.

[0114] FIG. 5b is a diagram (520) showing the change in resistance of a CNT-based composite sensor according to temperature change.

[0115] In this invention, sensors with various CNT concentrations (1.5 wt.%, 2.0 wt.%, 3.0 wt.%, 5.0 wt.%, etc.) are fabricated to measure the ratio of resistance change according to temperature change. This invention confirms the characteristic that resistance decreases rapidly as the temperature of the sensor increases. When the temperature reaches 60°C, the resistance of the sensor decreases by approximately 80%, and when it reaches 80°C, it decreases by approximately 100%. These results demonstrate that CNTs respond sensitively to temperature changes and exhibit an increase in electrical conductivity. This invention confirms that the range of resistance change according to temperature change becomes larger as the CNT concentration decreases, indicating that concentration directly affects the sensitivity of the sensor. Furthermore, when the CNT concentration is low (1.5 wt.%), the range of resistance change according to temperature is relatively large, demonstrating that low-concentration sensors are more effective in detecting temperature changes.

[0116] Figure 5c is a diagram (530) showing in detail the relationship between CNT concentration and electrical conductivity.

[0117] In the present invention, a characteristic is observed in which electrical conductivity increases exponentially as the CNT concentration increases. In the present invention, it is confirmed that electrical conductivity begins to increase rapidly when the CNT concentration reaches 1.5 wt.%, and reaches a saturation state at 3.0 wt.% or higher. When the CNT concentration is less than 1.5 wt.%, the conductive network is not sufficiently formed, so the electrical conductivity remains at a low level. In the present invention, it is confirmed that electrical sensitivity can be maximized by using a concentration of 1.5 wt.% or higher, and this can be set as a standard for sensor fabrication.

[0118] In the present invention, the optimal conditions for fabricating a CNT composite sensor can be determined based on the data shown in FIGS. 5a, 5b, and 5c.

[0119] For example, the present invention sets the number of screen printing cycles to seven or more to ensure the uniform formation of the CNT network and the stabilization of electrical conductivity. Additionally, the present invention maintains the CNT concentration at 1.5 wt.% to balance the sensitivity of the sensor with manufacturing costs. The sensor produced in this way can detect temperature changes and flames in real time and is suitable for early detection of abnormal signs inside the battery.

[0120] The CNT-based composite sensor according to the present invention possesses high-sensitivity and high-precision electrical characteristics through the optimization of screen printing techniques and CNT concentration. FIG. 5a clearly shows the relationship between the number of screen printing cycles and electrical conductivity, and FIG. 5b demonstrates the sensitivity of the sensor through the ratio of resistance change according to temperature change. FIG. 5c provides a criterion for setting the optimal CNT concentration through the correlation between CNT concentration and electrical conductivity. Based on this data, the present invention enables the design and fabrication of a sensor that rapidly and accurately detects the internal state of a battery.

[0121] Figure 6 is a diagram illustrating the operation method of a flame / temperature detection system using an electrical data measurement system.

[0122] Figure 6 illustrates the step-by-step operation process of a CNT-based flame and temperature sensing system that monitors the internal state of a battery in real time, analyzes data, detects the possibility of fire in advance, and ensures battery safety through power control. The system proceeds sequentially from start to end and includes all processes ranging from sensor data measurement, analysis, warning generation, to power cutoff.

[0123] When the system starts, the present invention activates all components for monitoring the internal state of the battery. The present invention initializes the sensing unit, measurement unit, analysis unit, warning signal generation unit, and power control unit, and completes preparations for real-time data collection from within the battery. At this stage, the system completes the initial setup tasks necessary to detect abnormal conditions that may occur within the battery.

[0124] In the present invention, electrical resistance data is measured in real time using a CNT-based composite sensor installed inside the battery by utilizing a sensing unit (601). In the present invention, a CNT composite designed so that the sensing unit is placed in the internal void space of the battery is utilized to sensitively detect changes in electrical resistance due to temperature changes. The sensing unit responds immediately to even minute temperature changes inside the battery by utilizing the temperature sensitivity characteristics of the CNT composite. In the present invention, electrical resistance data collected from the sensing unit is transmitted to a measurement unit, and the measurement unit precisely measures the electrical resistance data of the CNT composite and transmits it to an analysis unit. The present invention confirms that this data serves as key information for determining subsequent temperature changes and the possibility of fire occurrence.

[0125] In the present invention, the battery temperature is detected by using a measuring unit to calculate the internal battery temperature based on electrical resistance data transmitted from a sensing unit (602). In the present invention, the resistance change rate of a CNT composite sensor is analyzed to determine whether the temperature has reached a set threshold (e.g., 60°C or 80°C). The severity of the temperature change is evaluated by utilizing the characteristic that the sensor resistance decreases by approximately 80% when the internal battery temperature reaches 60°C and decreases by approximately 100% when it reaches 80°C. The system determines in real time whether the temperature has exceeded the threshold and transmits this to an analysis unit. In the present invention, the battery status is evaluated based on this data, and preparations are made for generating a warning signal and power control operations in the next step.

[0126] In the present invention, the internal state of the battery is evaluated based on the received data using an analysis unit (603). In the present invention, the analysis unit comprehensively analyzes the rate of change in temperature, the rate of change in electrical resistance, and whether a set threshold is exceeded to predict the possibility of an initial fire in real time. When the internal temperature of the battery exceeds a set threshold, the analysis unit activates a warning signal generator. In the present invention, the warning signal generator is configured to transmit a warning signal via an IoT network and to transmit the signal to a power control unit. The power control unit cuts off the battery power after receiving the warning signal. In the present invention, it is evaluated that cutting off the power plays an important role in preventing the possibility of an internal battery fire in advance.

[0127] When all analysis and control operations are completed, the system operation of the present invention is terminated. If the battery status is maintained stably and there are no additional abnormal signs, the system transitions to a shutdown state. The present invention is configured to maintain a monitoring state so that the system continues to collect real-time data and continuously detect potential risk factors.

[0128] The flame and temperature detection system according to the present invention utilizes a CNT-based composite sensor to monitor and analyze the internal state of a battery in real time, and describes a process of preventing fire hazards in advance through the generation of warning signals and power control.

[0129] FIG. 7 is a diagram that more specifically explains the analysis and power control method according to one embodiment.

[0130] Figure 7 specifically illustrates the analysis and control steps of the system based on temperature changes inside the battery, and includes key processes such as the rise in battery temperature, changes in the resistance of the CNT composite sensor, the generation of a warning signal, and power cutoff. This figure details automated procedures for detecting the possibility of fire in advance and preventing it.

[0131] The system measures the battery temperature in real time through a CNT-based composite sensor installed inside the battery and collects data on changes in electrical resistance as the temperature rises by utilizing the temperature sensitivity characteristics of the CNT composite. In the present invention, the data received through the measurement unit is analyzed, and it is determined whether the internal temperature of the battery has reached 60°C (701). 60°C is set as a reference temperature indicating an initial abnormal state in the system and is used as the first warning threshold for monitoring the battery status.

[0132] The resistance of the CNT-based composite sensor decreases by approximately 80% as the internal temperature of the battery reaches 60°C (702). In the present invention, it is confirmed that the characteristics of the CNT composite sensor are designed to respond sensitively to a rise in temperature. The sensing unit transmits this resistance reduction data to the measuring unit in real time, and the measuring unit precisely measures the received data. In the present invention, it is recognized that this resistance reduction is an important signal indicating an abnormal state inside the battery, and the data is transmitted to the analysis unit to further evaluate the battery condition.

[0133] The analysis unit evaluates the internal state of the battery based on data received from the measurement unit, detects that the internal temperature of the battery has exceeded a threshold of 60°C, and activates the warning signal generation unit based on this. In the present invention, the warning signal generation unit is linked with an IoT network and can send a warning signal to a battery management system (BMS) or an external monitoring device (703). The warning signal indicates that the internal temperature of the battery has exceeded a set range, thereby enabling appropriate preventive measures to be taken.

[0134] The internal temperature of the battery rises above 80°C (704), which indicates a state where the risk of fire increases rapidly. The analysis unit confirms that the internal temperature of the battery has reached 80°C and activates the warning signal generation unit and the power control unit based on this data. In the present invention, the system monitors the internal state of the battery in real time and confirms that it has transitioned to a state requiring urgent control work.

[0135] The resistance of the CNT-based composite sensor decreases by 100% as the internal temperature of the battery rises above 80°C (705). The present invention confirms that this decrease in resistance indicates a serious abnormal condition inside the battery and is a signal strongly suggesting the possibility of a fire. The sensing unit transmits this data to the measuring unit, and the measuring unit precisely measures it and then transmits it to the analysis unit. The analysis unit determines that there is a very high possibility of a fire occurring inside the battery when the resistance is reduced by 100% and decides to take immediate power cut-off measures.

[0136] The analysis unit activates the power control unit to cut off the battery power. In the present invention, it is confirmed that the AI-based analysis unit executes a power cutoff command based on collected data and judgment results (706). The power control unit operates as an automated system linked to an IoT network, eliminating the risk of fire inside the battery and preventing additional damage. In the present invention, power cutoff can ensure battery safety.

[0138] The device described above may be implemented as a hardware component, a software component, and / or a combination of a hardware component and a software component. For example, the device and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. In addition, other processing configurations, such as parallel processors, are also possible.

[0139] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0140] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the medium may be those specifically designed and configured for the embodiment, or they may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

[0141] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0142] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

Claim 1 A battery flame detection system for detecting flames and temperature changes inside a battery, comprising: a sensing unit including a carbon nanotube composite disposed inside the battery and having an electrical resistance that changes according to temperature changes; and a measuring unit that measures resistance information detected from the sensing unit in real time. Claim 2 A battery flame detection system according to claim 1, wherein the sensing part is a carbon nanotube composite fabricated using a screen printing technique and is disposed in an air gap space inside the battery. Claim 3 A battery flame detection system according to claim 1, characterized in that the measuring unit includes a warning signal generating unit that analyzes measured resistance information and generates a warning signal when the internal temperature of the battery exceeds a selected threshold. Claim 4 A battery flame detection system characterized in that, in paragraph 3, the warning signal generating unit is connected to a power control unit that cuts off battery power by linking the generated warning signal with an IoT network. Claim 5 A battery flame detection system according to claim 1, wherein the measuring unit further includes an analysis unit that calculates the rate of change in temperature inside the battery and predicts the possibility of an initial fire. Claim 6 A battery flame detection system according to claim 1, characterized in that the sensing unit has a structure in which a carbon nanotube composite and an insulating layer are combined, and is configured to detect temperature and flame changes more precisely by minimizing external interference. Claim 7 A method for manufacturing a carbon nanotube-based sensor, comprising the steps of: preparing a composite ink by mixing carbon nanotubes and polyurethane; transferring the composite ink onto an insulating substrate in a desired pattern using a screen printing technique; drying and curing the transferred composite ink to form a sensor; and configuring the formed sensor to detect temperature and flame changes by placing it inside a battery enclosure. Claim 8 A method for manufacturing a sensor according to claim 7, wherein the step of preparing the composite ink comprises the step of optimizing electrical sensitivity by mixing carbon nanotubes into a polyurethane matrix at 1.5 weight%. Claim 9 A method for manufacturing a sensor according to claim 7, wherein the screen printing technique is performed by transferring composite ink with a thickness of 0.1 mm and designing the transferred pattern in a form that is continuously partitioned with a central round area and on both sides thereof. Claim 10 A method for manufacturing a sensor according to claim 7, wherein the step of placing a sensor inside the battery enclosure is designed such that a sensor formed on a PET film is placed in the gap space between battery modules, and the resistance is reduced by at least 80% when the temperature reaches 60°C and by at least 100% when the temperature reaches 80°C.

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