Hydrogen smoke targeted sensor for lithium battery thermal runaway and detection method

Abstract

The invention discloses a hydrogen smoke targeted sensor for lithium battery thermal runaway and a detection method, and relates to the technical field of sensors. The sensor comprises a substrate, a frame and a barrier plate, the frame and the barrier plate are fixedly arranged on the substrate, and the barrier plate divides the interior of the frame into two cavities; the first chamber is provided with a light-emitting diode and a processing unit, the second chamber is provided with two photodiodes with consistent structural performance and function, the surface of one photodiode is provided with a hydrogen-sensitive film, each element is electrically connected with the processing unit, and a top air inlet structure is arranged above the frame. According to the detection method disclosed by the invention, the output value of the photodiode and the light transmittance of the hydrogen-sensitive film are defined, the concentrations of smoke and hydrogen are calibrated through the standard experiment box, and then the targeted dual-function detection of the hydrogen and the smoke in the lithium battery thermal runaway early warning is realized according to the output value of the photodiode and the light transmittance change in different scenes. And a timely and reliable basis is provided for lithium battery thermal runaway early warning, and the application value is high.

Description

Technical Field

[0001] This invention relates to the field of lithium battery thermal runaway early warning technology, and in particular to a hydrogen smoke targeting sensor and detection method for lithium battery thermal runaway. Background Technology

[0002] Lithium-ion batteries play a crucial role in new energy and electrochemical energy storage due to their advantages in energy density, cycle life, and service life. However, the difficulty in assessing their safety status, the prominent issue of thermal runaway, and the increasing risk of combustion and explosion have become key bottlenecks restricting the large-scale application of energy storage systems, necessitating in-depth research into lithium battery thermal runaway early warning technology.

[0003] Currently, existing sensors are mainly used for single-signal measurements or multi-sensor composite measurements, including different sensors for hydrogen (H2) and smoke. Hydrogen (H2) sensors mainly include electrochemical H2 sensors and semiconductor H2 sensors. Electrochemical H2 sensors are commercially available and considered the most advanced H2 sensor technology. Electrochemical H2 sensors operate by converting the redox reaction of H2 into an electrical signal. Electrochemical sensors exhibit high sensitivity and selectivity for H2, with a low detection limit, but are extremely sensitive to oxygen and humidity levels, and the systems are relatively complex, requiring high manufacturing costs. Semiconductor hydrogen sensors convert the signal of a chemical / physical reaction into an electrical signal, which manifests as a change in current under a certain voltage, used to detect H2 concentration. They have advantages such as high sensing efficiency, low manufacturing cost, and portability. However, semiconductor H2 sensors also have some problems, such as poor resistance to cross-interference and high operating temperature. Late-stage detection of battery thermal runaway mainly relies on smoke detection. Current smoke detectors mainly include ionization smoke detectors and photoelectric smoke detectors. Ionization smoke detectors use an ionization chamber within the detector to detect external smoke and issue an alarm signal. However, ionization smoke detectors have largely disappeared from the market because their ionization chambers require the use of radioactive elements. The mainstream point-type smoke detectors on the market are photoelectric smoke detectors. Their fire detection principle utilizes the characteristic that fires generally produce smoke; the absorption and scattering of smoke particles alters the propagation characteristics of light, combining optical and electronic technologies to detect fires. Currently, lithium battery thermal runaway detection utilizes the aforementioned existing sensors with adaptations to complete the monitoring work. The working principles of these two types of sensors, and even a single type of sensor, are different, each with its own advantages and disadvantages. They may be used independently or in combination. Lithium battery thermal runaway detection has low adaptability, low integration, and high cost; there are no sensors specifically designed for lithium battery thermal runaway early warning.

[0004] Chinese patent document CN116386257A discloses a "hydrogen-based composite lithium battery fire detection device," which integrates a hydrogen sensor, a carbon monoxide sensor, a temperature sensor, a VOC sensor, and a smoke sensor to monitor battery thermal runaway and provide early warning of lithium battery thermal runaway. While this technical solution integrates multiple sensors and offers comprehensive functionality, its complex structure and high cost are its biggest drawbacks. Therefore, there is an urgent need to develop a hydrogen smoke-targeting sensor for lithium battery thermal runaway to address the problems of complex structure and high cost in existing solutions. Summary of the Invention

[0005] Technical objective: To overcome the shortcomings of existing technologies and solve the problems of low adaptability to lithium battery thermal runaway detection, low integration and high cost, and the lack of sensors specifically designed for lithium battery thermal runaway early warning.

[0006] Technical Solution: To achieve the above objectives, this invention provides a hydrogen smoke targeting sensor for lithium battery thermal runaway, comprising a substrate, a frame, and a barrier plate. The frame is fixedly mounted on the substrate; the barrier plate is fixedly mounted on the substrate, with both ends of the barrier plate fixedly connected to the inner wall of the frame, dividing the frame into a first chamber and a second chamber; the substrate and the barrier plate are made of completely opaque material; the height of the barrier plate is lower than the height of the frame; characterized in that a light-emitting diode and a processing unit are provided in the first chamber, and a first photodiode and a second photodiode are provided in the second chamber, the structure, performance parameters, and functions of the first photodiode and the second photodiode being completely identical; a hydrogen-sensitive thin film is provided on the surface of the second photodiode; the heights of the light-emitting diode, the first photodiode, and the second photodiode are all lower than the height of the barrier plate, and the light-emitting diode, the first photodiode, and the second photodiode are all electrically connected to the processing unit; a top air intake structure is threaded onto the top of the frame.

[0007] Furthermore, the top air intake structure includes an annular main structure located above the frame. The annular main structure has two outwardly extending connecting ears on its outer periphery, and each connecting ear has a through hole for assembly connection. The annular main structure has multiple arrayed support ribs inside, which are equidistantly spaced along the circumference of the annular main structure, and hollow areas are formed between adjacent support ribs.

[0008] Furthermore, the supporting rib plate has an annular flange at the end away from the annular main structure. The annular flange is coaxially arranged with the annular main structure, and the upper surface of the annular flange is flush with the end face of the supporting rib plate.

[0009] Furthermore, the substrate and barrier plate are made of any one of ceramic, copper, or resin.

[0010] Furthermore, the light-emitting diode is an infrared light-emitting diode or a blue light-emitting diode.

[0011] Furthermore, the hydrogen-sensitive film material is any one of tungsten trioxide, target trioxide, molybdenum trioxide, palladium, palladium-yttrium alloy, polyaniline, and yttrium hydride.

[0012] A method for detecting hydrogen smoke targeting sensors for lithium battery thermal runaway, applied to the hydrogen smoke targeting sensor for lithium battery thermal runaway as described in any one of claims 1 to 6, characterized in that it comprises:

[0013] [S1] Measurement data definition: The output value of the first photodiode is the value of the light signal converted into an electrical signal, denoted as P1, with the unit being mV; the output value of the second photodiode is the value of the light signal converted into an electrical signal after being blocked by the hydrogen-sensitive film, which is an organic combination of hydrogen color change and photoelectric conversion, denoted as P2, with the unit being mV; the transmittance of the hydrogen-sensitive film is X, and the transmittance X = P2 / P1, with the unit being %.

[0014] [S2] Measurement data calibration and processing:

[0015] [S2.1] Smoke concentration calibration and treatment, P1 标定 The P1 value mentioned in step [S1] is the output value after calibration by a standard smoke test chamber, and the smoke concentration Ps is the value obtained by calibrating the P1 value. 标定 Write the output value after processing by the MCU, in mg / m³. 3 When P1 is the baseline value, Ps is 0; as the smoke concentration increases, the Ps value gradually increases.

[0016] [S2.2] Hydrogen concentration calibration and processing, Ph 标定 The transmittance X value mentioned in step [S1] is the output value after calibration in a standard hydrogen test chamber, and the hydrogen concentration Ph is the value obtained by calibrating Ph. 标定 The output value after processing by the MCU is written to the processing unit, in ppm; when the transmittance X = 100%, the hydrogen concentration is 0; as the transmittance X decreases, the hydrogen concentration value Ph gradually increases;

[0017] [S3] Hydrogen Smoke Targeted Detection Method:

[0018] Detection Scenario 1: When no smoke or hydrogen enters the sensor, the hydrogen-sensitive film 4 above the second photodiode remains unchanged; the light emitted by the light-emitting diode is scattered, and the lower light, after being blocked by the barrier plate, cannot reach the first photodiode and the second photodiode covered by the hydrogen-sensitive film; the upper light shines into the space, and due to the influence of the top air intake structure, some of the light is refracted to the first photodiode and the second photodiode covered by the hydrogen-sensitive film; at this time, the output values ​​of the first photodiode and the second photodiode are both reference values, i.e., P1 = P2, and the transmittance X = 100%; that is, the detection result of Scenario 1 is: smoke concentration Ps = 0, hydrogen concentration Ph = 0;

[0019] Detection Scenario 2: When only smoke particles enter the sensor, the hydrogen-sensitive film above the second photodiode remains unchanged; the light emitted by the LED is refracted when it encounters smoke particles, and some of the light is refracted to the first photodiode below and the second photodiode covered by the hydrogen-sensitive film; at this time, the output values ​​of the first photodiode and the second photodiode are the same value that is greater than the reference value, i.e., P1 = P2, and the transmittance X = 100%; that is, the detection result of Scenario 2 is: smoke concentration is Ps, Ps>0, and hydrogen concentration is Ph=0;

[0020] In scenario 3, when only hydrogen gas enters the sensor, the hydrogen-sensitive film above the second photodiode 6 changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode and the second photodiode covered by the hydrogen-sensitive film, and there is no refraction of light when it encounters smoke particles. At this time, the output value P1 of the first photodiode is the reference value, and the output value P2 of the second photodiode is less than the reference value, that is, P1>P2, and the transmittance X<100%. Therefore, the detection result of scenario 3 is: the smoke concentration is Ps=0, and the hydrogen concentration is Ph, Ph>0.

[0021] In scenario 4, when smoke particles and hydrogen gas simultaneously enter the area above the sensor, the hydrogen-sensitive film above the second photodiode changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode and the second photodiode covered by the hydrogen-sensitive film. When the light emitted by the LED encounters smoke particles, it is refracted to the first photodiode and the second photodiode covered by the hydrogen-sensitive film below. At this time, the output value of the first photodiode is greater than the reference value, and the output value P2 of the second photodiode is less than the reference value, i.e., P1>P2, and the transmittance X<100%. Therefore, the detection result of scenario 4 is: the smoke concentration is Ps, Ps>0, and the hydrogen concentration is Ph, Ph>0.

[0022] Furthermore, the range of smoke concentration calibration and treatment in step [S2.1] is: 0~100mg / m³ 3 Among them, 7mg / m 3The smoke concentration level 1 alarm threshold is 14 mg / m³. 3 This is the secondary alarm threshold for smoke concentration.

[0023] Further, the range of hydrogen concentration calibration and processing in step [S2.2] is 0 to 2000 ppm; where 200 ppm is the first-level alarm threshold for hydrogen concentration and 800 ppm is the second-level alarm threshold for hydrogen concentration.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention provides a hydrogen smoke targeting sensor for lithium battery thermal runaway, which can realize targeted dual-function detection of hydrogen and smoke in lithium battery thermal runaway early warning, can accurately capture hydrogen and smoke signals released in the early stage of thermal runaway, provide timely and reliable basis for lithium battery thermal runaway early warning, and improve the timeliness and accuracy of early warning.

[0026] 2. This invention provides a hydrogen smoke targeting sensor for lithium battery thermal runaway, which realizes multiple detection functions integrated by a single sensor. It can measure smoke concentration and hydrogen concentration separately, and can also accurately detect the concentration of both in a complex environment where hydrogen and smoke are mixed. The system has a simple structure and low manufacturing cost.

[0027] 3. This invention provides a hydrogen smoke targeting sensor for lithium battery thermal runaway. Through calibration processing, the output value of the photodiode is correlated with the standard concentration. In a mixed gas, the influence of smoke and hydrogen on the light signal can be effectively distinguished, and the smoke concentration and hydrogen concentration can be calculated separately, ensuring the accuracy and stability of data processing in complex scenarios.

[0028] 4. This invention provides a hydrogen smoke targeting sensor for lithium battery thermal runaway. It uses a hydrogen-sensitive thin film to achieve an organic combination of hydrogen color change and photoelectric conversion. It utilizes the characteristic that its transmittance changes with hydrogen concentration to complete the detection in conjunction with a photodiode. It has fast detection speed, high accuracy and good overall performance. Attached Figure Description

[0029] Figure 1 This is an overall structural diagram of a hydrogen smoke targeting sensor used for thermal runaway of lithium batteries;

[0030] Figure 2 This is a diagram of the top air intake structure of a hydrogen smoke targeting sensor used for thermal runaway of lithium batteries.

[0031] Figure 3 This is a hydrogen smoke targeting sensor for lithium battery thermal runaway, showing the smoke and hydrogen concentration calibration process.

[0032] Figure 4 It is a hydrogen smoke targeting sensor for lithium battery thermal runaway, used to calibrate smoke concentration processing curves.

[0033] Figure 5 It is a hydrogen smoke targeted sensor for lithium battery thermal runaway, used for hydrogen concentration calibration processing curves.

[0034] Explanation of reference numerals in the attached drawings: 1. Substrate; 2. Frame; 3. Barrier plate; 4. Hydrogen-sensitive film; 5. First photodiode; 6. Second photodiode; 7. First chamber; 8. Second chamber; 9. Light-emitting diode; 10. Annular main structure; 11. Connecting ear; 12. Supporting rib; 13. Annular flange. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1 To be continued Figure 2 The principles and features of the present invention are described, and the examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0036] Example 1 is a hydrogen smoke targeting sensor for lithium battery thermal runaway, such as... Figure 1 As shown, the system includes a base 1, a frame 2, and a barrier plate 3. The frame 2 is fixedly mounted on the base 1. The barrier plate 3 is fixedly mounted on the base 1, with both ends of the barrier plate 3 fixedly connected to the inner wall of the frame 2, dividing the frame 2 into a first chamber 7 and a second chamber 8. The base 1 and the barrier plate 3 are made of completely opaque material. The height of the barrier plate 3 is lower than the height of the frame 2. The base 1 and the barrier plate 3 are made of ceramic. The first chamber 7 contains an infrared light-emitting diode (LED) 9 and a processing unit. The second chamber 8 contains a first photodiode 5 and a second photodiode 6. The first photodiode 5 and the second photodiode 6 have the same structure, performance parameters, and functions. The surface of the second photodiode 6 is covered with a hydrogen-sensitive film 4. The heights of the LED 9, the first photodiode 5, and the second photodiode 6 are all lower than the height of the barrier plate 3. The LED 9, the first photodiode 5, and the second photodiode 6 are all electrically connected to the processing unit. A top air intake structure is threaded onto the top of the frame 2. The LED 9 is an infrared LED, and the hydrogen-sensitive film 4 is made of tungsten trioxide.

[0037] Specifically, such as Figure 2 As shown, the top air intake structure includes an annular main structure 10, which is located above the frame. The annular main structure 10 has two outwardly extending connecting ears 11 on its outer periphery, and each connecting ear 11 has a through hole for assembly connection. The annular main structure 10 has multiple arrayed support ribs 12 inside, which are equidistantly spaced along the circumference of the annular main structure 10, and hollow areas are formed between adjacent support ribs 12.

[0038] Specifically, the supporting rib plate 12 has an annular flange 13 at the end away from the annular main structure 10. The annular flange 13 is coaxially arranged with the annular main structure 10, and the upper surface of the annular flange 13 is flush with the end face of the supporting rib plate 12.

[0039] The first photodiode 5 and the second photodiode 6 are photodiodes used to receive optical signals and convert them into current signals. A sampling resistor or a cross-impedance amplifier is then used to convert the current signals into voltage signals. The hydrogen-sensitive film 4 is a hydrogen-chromic material; it is transparent in the absence of hydrogen gas, but its color gradually deepens and its transmittance gradually decreases as the hydrogen concentration increases. Its transmittance is proportional to the hydrogen concentration. This section describes existing technology in the optoelectronic field and will not be elaborated upon here.

[0040] Working principle: Smoke particles, hydrogen, and air enter the target sensor through the hollow area between the top air intake structure support ribs 12. The light emitted by the LED 9 is diffused; the lower light is blocked by the barrier plate 3 and cannot reach the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4. The upper light shines into the space, and due to the influence of the top air intake structure, smoke particles, and hydrogen, some of the light is refracted to the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4. The color of the hydrogen-sensitive film 4 gradually deepens as the hydrogen concentration increases, thus affecting the output value of the second photodiode 6. The output values ​​of the first photodiode 5 and the second photodiode 6 are output through the processing unit. The concentration of smoke particles and hydrogen is determined based on the changes in the output values. The specific determination process is described in Example 2.

[0041] Example 2 is a method for detecting hydrogen fumes using a targeted sensor for lithium battery thermal runaway, comprising:

[0042] [S1] Definition of measurement data: The output value of the first photodiode 5 is the value of the light signal converted into an electrical signal, denoted as P1, and the unit is mV; the output value of the second photodiode 6 is the value of the light signal converted into an electrical signal after being blocked by the hydrogen-sensitive film 4, which is an organic combination of hydrogen color change and photoelectric conversion, denoted as P2, and the unit is mV; the transmittance of the hydrogen-sensitive film 4 is X, and the transmittance X = P2 / P1, the unit is %.

[0043] [S2] Measurement data calibration and processing, such as Figure 3 As shown:

[0044] [S2.1] Smoke concentration calibration and treatment, P1 标定 The output value of P1 in step [S1] is the value after calibration using a standard smoke test chamber. The smoke concentration Ps is the value of P1 after calibration. 标定 Write the output value after processing by the MCU, in mg / m³. 3When P1 is the baseline value, Ps is 0; as the smoke concentration increases, the Ps value gradually increases; the range for smoke concentration calibration and treatment in this invention is: 0~100mg / m³. 3 ;like Figure 4 As shown, 7mg / m 3 The smoke concentration level 1 alarm threshold is 14 mg / m³. 3 This is the secondary alarm threshold for smoke concentration.

[0045] [S2.2] Hydrogen concentration calibration and processing, Ph 标定 The transmittance X value in step [S1] is the output value after calibration in a standard hydrogen test chamber, and the hydrogen concentration Ph is the value obtained by setting Ph as the standard hydrogen test chamber. 标定 The output value after processing by the MCU is written into the processing unit, in ppm; when the transmittance X = 100%, the hydrogen concentration is 0; as the transmittance X decreases, the hydrogen concentration value Ph gradually increases; the range of hydrogen concentration calibration and processing in this invention is 0~2000ppm; Figure 5 As shown, 200ppm is the first-level alarm threshold for hydrogen concentration, and 800ppm is the second-level alarm threshold for hydrogen concentration.

[0046] [S3] Hydrogen Smoke Targeted Detection Method:

[0047] Detection Scenario 1: When no smoke or hydrogen enters the sensor, the hydrogen-sensitive film 4 above the second photodiode 6 does not change color; the light emitted by the light-emitting diode 9 is scattered, and the lower light is blocked by the barrier plate 3 and cannot reach the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4; the upper light shines into the space, and due to the influence of the top air intake structure, some of the light is refracted to the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4; at this time, the output values ​​of the first photodiode 5 and the second photodiode 6 are both reference values, that is, P1 = P2, and the transmittance X = P2 / P1 is 100%; that is, the detection result of Scenario 1 is: smoke concentration Ps = 0, hydrogen concentration Ph = 0;

[0048] Detection Scenario 2: When only smoke particles enter the sensor, the hydrogen-sensitive film 4 above the second photodiode 6 remains unchanged; the light emitted by the light-emitting diode 9 is refracted when it encounters smoke particles, and some of the light is refracted to the first photodiode 5 below and the second photodiode 6 covered by the hydrogen-sensitive film 4; at this time, the output value of the first photodiode 5 and the output value of the second photodiode 6 are the same value that are greater than the reference value, that is, P1 = P2, and the transmittance X = P2 / P1 is 100%; that is, the detection result of Scenario 2 is: smoke concentration is Ps, Ps>0, and hydrogen concentration is Ph=0;

[0049] In scenario 3, when only hydrogen gas enters the sensor, the hydrogen-sensitive film 4 above the second photodiode 6 changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4, and there is no light refraction when it encounters smoke particles. At this time, the output value P1 of the first photodiode 5 is the reference value, and the output value P2 of the second photodiode 6 is less than the reference value, that is, P1>P2, and the transmittance X = P2 / P1, X<100%. Therefore, the detection result of scenario 3 is: the smoke concentration is Ps=0, the hydrogen concentration is Ph, and Ph>0.

[0050] In scenario 4, when smoke particles and hydrogen gas simultaneously enter the area above the sensor, the hydrogen-sensitive film 4 above the second photodiode 6 changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4. When the light emitted by the light-emitting diode 9 encounters smoke particles, it is refracted to the first photodiode 5 and the second photodiode 6 covered by the hydrogen-sensitive film 4 below. At this time, the output value of the first photodiode 5 is greater than the reference value, and the output value P2 of the second photodiode 6 is less than the reference value, i.e., P1>P2, and the transmittance X = P2 / P1, X<100%. Therefore, the detection result of scenario 4 is: the smoke concentration is Ps, Ps>0, and the hydrogen concentration is Ph, Ph>0.

[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydrogen smoke targeting sensor for lithium battery thermal runaway, comprising a substrate (1), a frame (2), and a barrier plate (3), wherein the frame (2) is fixedly mounted on the substrate (1); the barrier plate (3) is fixedly mounted on the substrate (1), and both ends of the barrier plate (3) are fixedly connected to the inner wall of the frame (2), dividing the frame (2) into a first chamber (7) and a second chamber (8); the substrate (1) and the barrier plate (3) are made of completely opaque material; the height of the barrier plate (3) is lower than the height of the frame (2); characterized in that, The first chamber (7) is equipped with a light-emitting diode (9) and a processing unit. The second chamber (8) is equipped with a first photodiode (5) and a second photodiode (6). The structure, performance parameters and functions of the first photodiode (5) and the second photodiode (6) are completely identical. The surface of the second photodiode (6) is provided with a hydrogen-sensitive film (4). The height of the light-emitting diode (9), the first photodiode (5) and the second photodiode (6) is lower than the height of the barrier plate (3). The light-emitting diode (9), the first photodiode (5) and the second photodiode (6) are all electrically connected to the processing unit. A top air intake structure is threaded on the top of the frame (2).

2. The hydrogen smoke targeting sensor for lithium battery thermal runaway according to claim 1, characterized in that, The top air intake structure includes an annular main structure (10), which is located above the frame (2). The annular main structure (10) has two outwardly extending connecting ears (11) on its outer periphery. Each connecting ear (11) has a through hole for assembly connection. The annular main structure (10) has multiple arrayed support ribs (12) inside. The support ribs (12) are equidistantly spaced along the circumference of the annular main structure (10), and a hollow area is formed between adjacent support ribs (12).

3. A hydrogen smoke targeting sensor for lithium battery thermal runaway according to claim 2, characterized in that, The supporting rib (12) has an annular flange (13) at one end away from the annular main structure (10). The annular flange (13) is coaxially arranged with the annular main structure (10), and the upper surface of the annular flange (13) is flush with the end face of the supporting rib (12).

4. A hydrogen smoke targeting sensor for lithium battery thermal runaway according to claim 1, characterized in that, The substrate (1) and the barrier plate (3) are made of any one of ceramic, copper, or resin.

5. A hydrogen smoke targeting sensor for lithium battery thermal runaway according to claim 1, characterized in that, The light-emitting diode (9) is an infrared light-emitting diode or a blue light-emitting diode.

6. A hydrogen smoke targeting sensor for lithium battery thermal runaway according to claim 1, characterized in that, The hydrogen-sensitive film (4) is made of any one of tungsten trioxide, target trioxide, molybdenum trioxide, palladium, palladium-yttrium alloy, polyaniline, and yttrium hydride.

7. A method for detecting hydrogen smoke targeting sensors for lithium battery thermal runaway, applied to the hydrogen smoke targeting sensor for lithium battery thermal runaway as described in any one of claims 1 to 6, characterized in that, include: [S1] Definition of measurement data: The output value of the first photodiode (5) is the value of the light signal converted into an electrical signal, denoted as P1, with the unit being mV; the output value of the second photodiode (6) is the value of the light signal converted into an electrical signal after being blocked by the hydrogen-sensitive film (4), which is an organic combination of hydrogen color change and photoelectric conversion, denoted as P2, with the unit being mV; the transmittance of the hydrogen-sensitive film (4) is X, and the transmittance X = P2 / P1, with the unit being %. [S2] Measurement data calibration and processing: [S2.1] Smoke concentration calibration and treatment, P1 标定 The P1 value mentioned in step [S1] is the output value after calibration by a standard smoke test chamber, and the smoke concentration Ps is the value obtained by calibrating the P1 value. 标定 Write the output value after processing by the MCU, in mg / m³. 3 ; When P1 is the baseline value, Ps is 0; as the smoke concentration increases, the Ps value gradually increases. [S2.2] Hydrogen concentration calibration and processing, Ph 标定 The transmittance X value mentioned in step [S1] is the output value after calibration in a standard hydrogen test chamber, and the hydrogen concentration Ph is the value obtained by calibrating Ph. 标定 The output value after processing by the MCU is written to the processing unit, in ppm; when the transmittance X = 100%, the hydrogen concentration is 0; as the transmittance X decreases, the hydrogen concentration value Ph gradually increases; [S3] Hydrogen Smoke Targeted Detection Method: Detection scenario 1: When no smoke or hydrogen enters the sensor, the hydrogen-sensitive film (4) above the second photodiode (6) does not change color; the light emitted by the light-emitting diode (9) is scattered, and the light from the bottom is blocked by the barrier plate (3) and cannot reach the first photodiode (5) and the second photodiode (6) covered by the hydrogen-sensitive film (4); the light from the top shines into the space, and due to the influence of the top air intake structure, some of the light is refracted to the first photodiode (5) and the second photodiode (6) covered by the hydrogen-sensitive film (4); at this time, the output values ​​of the first photodiode (5) and the second photodiode (6) are both reference values, that is, P1 = P2, and the transmittance X = 100%; that is, the detection result of scenario 1 is: smoke concentration is Ps = 0, and hydrogen concentration Ph = 0; Detection scenario 2: When only smoke particles enter the sensor, the hydrogen-sensitive film (4) above the second photodiode (6) does not change color; the light emitted by the light-emitting diode (9) is refracted when it encounters smoke particles, and some of the light is refracted to the first photodiode (5) below and the second photodiode (6) covered by the hydrogen-sensitive film (4); at this time, the output value of the first photodiode (5) and the output value of the second photodiode (6) are the same value that is greater than the reference value, that is, P1 = P2, and the transmittance X = 100%; that is, the detection result of scenario 2 is: smoke concentration is Ps, Ps>0, and hydrogen concentration is Ph = 0; In scenario 3, when only hydrogen enters the sensor, the hydrogen-sensitive film (4) above the second photodiode (6) changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode (5) and the second photodiode (6) covered by the hydrogen-sensitive film (4), and no light is refracted by smoke particles. At this time, the output value P1 of the first photodiode (5) is the reference value, and the output value P2 of the second photodiode (6) is less than the reference value, that is, P1>P2, and the transmittance X<100%. The detection result of scenario 3 is: the smoke concentration is Ps=0, and the hydrogen concentration is Ph, Ph>0. In scenario 4, when smoke particles and hydrogen enter the sensor simultaneously, the hydrogen-sensitive film (4) above the second photodiode (6) changes color with the hydrogen concentration. Due to the influence of the top air intake structure, some light returns to the first photodiode (5) and the second photodiode (6) covered by the hydrogen-sensitive film (4). When the light emitted by the light-emitting diode (9) encounters smoke particles, it is refracted to the first photodiode (5) below and the second photodiode (6) covered by the hydrogen-sensitive film (4). At this time, the output value of the first photodiode (5) is greater than the reference value, and the output value P2 of the second photodiode (6) is less than the reference value, i.e., P1>P2, and the transmittance X<100%. The detection result of scenario 4 is: the smoke concentration is Ps, Ps>0, and the hydrogen concentration is Ph, Ph>0.

8. A method for detecting hydrogen fumes using a targeted sensor for lithium battery thermal runaway according to claim 7, characterized in that, The range for smoke concentration calibration and treatment in step [S2.1] is: 0~100mg / m³ 3 Among them, 7mg / m 3 The smoke concentration level 1 alarm threshold is 14 mg / m³. 3 This is the secondary alarm threshold for smoke concentration.

9. A method for detecting hydrogen fumes using a targeted sensor for lithium battery thermal runaway according to claim 8, characterized in that, The range of hydrogen concentration calibration and processing in step [S2.2] is 0 to 2000 ppm; where 200 ppm is the first-level alarm threshold for hydrogen concentration and 800 ppm is the second-level alarm threshold for hydrogen concentration.

Images