System for detecting thermal runaway of battery

Abstract

The system for detecting thermal runaway of a battery is configured to early detect thermal runaway of a battery module comprising a casing and multiple battery cells disposed in the casing. The system comprises a gas sensor module for detecting gaseous materials included in mixed gases discharged from the battery module, and a processor for processing signals from the gas sensor module. The system is configured to early detect thermal runaway of the battery module by determining whether or not gaseous materials are generated in the battery module and detected by the gas sensor module.

Description

Battery thermal runaway detection system

[0001] The present disclosure relates to a battery thermal runaway detection system, and more particularly, to a thermal runaway detection system for early detection of the possibility of thermal runaway in a secondary battery such as a lithium ion battery that has the possibility of thermal runaway.

[0002] In response to the depletion of fossil fuels and environmental pollution, development of battery-powered vehicles, ships, and aircraft is actively underway. Furthermore, as the military's weapon systems and combat support systems become increasingly electronic and operate without spatial or temporal constraints, the number of systems and equipment requiring batteries is steadily increasing.

[0003] However, lithium-ion batteries, which are secondary batteries mainly used in electric vehicles, have a thermal runaway problem, and the severity of this has been introduced in various media.

[0004] Lithium-ion batteries are known to be incapable of extinguishing fires caused by thermal runaway before they completely burn out. This can not only cause damage to the primary battery itself, but also to the vehicle in which it is mounted. Furthermore, it can even lead to human casualties due to explosion.

[0005] Current research on batteries is focused on achieving high efficiency, high capacity, and high density batteries, which in turn has led to a proportionally higher risk of fire.

[0006] To solve this thermal runaway problem, it is important to detect abnormal signs in advance before secondary battery ignition occurs and secure the golden time through this.

[0007] Techniques have been developed to detect thermal runaway in secondary batteries. However, while conventional techniques attempt to estimate thermal runaway through complex computations on battery signals, these methods struggle to monitor battery state changes quickly enough to prevent thermal runaway in advance.

[0008] In relation to the problems of the above-mentioned prior art, a thermal runaway pre-detection system according to one embodiment is provided, which can prevent a battery fire due to thermal runaway by monitoring the state of the battery in real time.

[0009] A battery thermal runaway detection system according to one embodiment of the present disclosure is a battery thermal runaway detection system that detects thermal runaway of a battery module having a casing and a plurality of battery cells arranged inside the casing at an early stage, the system including a gas sensor module that detects a gaseous substance included in a mixed gas discharged from the battery module, and a processor that processes a signal of the gas sensor module, and detects thermal runaway of the battery module at an early stage by determining whether the gaseous substance is generated inside the battery module and detected by the gas sensor module.

[0010] According to one embodiment, the gas sensor module detects a component of a gaseous substance included in the mixed gas, and early detects thermal runaway of the battery module by detecting whether a gaseous substance of a specific component is generated inside the battery module and detected by the gas sensor module.

[0011] According to one embodiment, the gas sensor module is disposed outside the casing and communicates with the interior of the casing through a discharge pipe.

[0012] In one embodiment, a plurality of battery modules form a battery pack, and the gas sensor module is connected to a plurality of exhaust pipes connected to each of the plurality of battery modules, thereby communicating with all of the plurality of battery modules.

[0013] According to one embodiment, the plurality of discharge pipes are connected to a gas inlet of the gas sensor module via a valve, and the processor controls the valve so that a mixed gas discharged from the plurality of battery modules is injected into the gas sensor module in a predetermined order.

[0014] According to one embodiment, the thermal runaway detection system of the battery further includes a strain gauge that detects a deformation amount due to expansion of the battery cell, and when a condition is met in which a gaseous substance of the specific component is detected by the gas sensor module and deformation of the battery cell is detected by the strain gauge, the processor determines that thermal runaway of the battery module is in progress.

[0015] In one embodiment, the processor determines whether deformation of the battery cell is detected by the strain gauge when the gaseous substance of the specific component is detected by the gas sensor module.

[0016] In one embodiment, a plurality of said strain gauges are attached to each of said plurality of battery cells.

[0017] According to one embodiment, the gas sensor module detects gaseous substances contained in a mixed gas discharged from the battery module by separating them by component.

[0018] According to one embodiment, the gas sensor module includes a concentrator that filters and concentrates gaseous substances contained in the mixed gas, a separation unit that separates gaseous substances flowing from the concentrator into components, and a sensing unit that detects gaseous substances flowing out from the separation unit.

[0019] According to one embodiment, the separation unit includes a separation path through which the gaseous substance moves at different speeds inside according to the component and is separated by component and flows out with a time difference, and the sensing unit detects the gaseous substance that has escaped the separation path with a time difference.

[0020] In one embodiment, nanoscale nanorods are formed within the separation path that interfere with the flow of gaseous substances flowing through the separation path.

[0021] According to one embodiment, the sensing unit includes an electrode pattern, a carbon structure positioned on the electrode pattern and having pores in which gas particles can be adsorbed, and a measuring unit electrically connected to the electrode pattern and configured to detect the gas particles by measuring a change in the electrical characteristics of the electrode pattern when the carbon structure is exposed to the gas particles.

[0022] According to one embodiment, the sensing unit detects the gaseous substance by applying ultraviolet light to the gaseous substance flowing out of the separation unit and measuring a voltage change due to electrons dissociating from the gaseous substance.

[0023] According to one embodiment, the concentration unit, the separation unit, and the sensor unit are formed on one substrate.

[0024] Figure 1 is a conceptual diagram illustrating an example of a battery module.

[0025] Figure 2 is a conceptual diagram illustrating an example of a battery pack.

[0026] FIG. 3 illustrates a partial configuration of a gas sensor module according to one embodiment of a thermal runaway detection system.

[0027] Fig. 4 is an enlarged view of the concentration section of the gas sensor module of Fig. 3.

[0028] Figure 5 schematically illustrates the interior of the separation path of the gas sensor module of Figure 3.

[0029] Figures 6a to 6g are drawings explaining a method of forming the separation path of Figure 5.

[0030] Fig. 7 is a schematic diagram showing the interior of the separation path of the gas sensor module of Fig. 3.

[0031] Fig. 8 is a drawing explaining the configuration of a sensing unit according to one embodiment of a gas sensor module.

[0032] Figure 9 is a graph showing an example of a detection result detected through a sensing unit.

[0033] Fig. 10 is a drawing explaining the configuration of a sensing unit according to another embodiment of a gas sensor module.

[0034] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. While the present disclosure has been described with reference to the embodiments illustrated in the drawings, this is described as one embodiment, and the technical concept of the present disclosure and its core configuration and operation are not limited thereby.

[0035] Battery Thermal Runaway

[0036] Thermal runaway of a battery is caused by three main factors: overcharging, overdischarging, and temperature. This causes the battery to run away through the stages of off-gas emission, smoke generation, and ignition. In the initial stage of the thermal runaway phenomenon, off-gas emission also occurs.

[0037] Because the time from initial gas emission to ignition is short, it is important to detect from the low concentration state when initial gas emission begins.

[0038] Specifically, in the 90°C to 120°C range, the cathode and electrolyte solid-state interface (SEI layer) decompose, generating gas and heat. Subsequently, the SEI layer continues to form and decompose until around 220°C, when the graphite cathode is completely decomposed.

[0039] Common membrane materials (polyethylene, polypropylene) begin to decompose around 130°C, which causes local short circuits.

[0040] The electrolyte is easily decomposed in the range of 15 to 200℃, and general cathode materials (NMC, LFP) decompose above 220℃ and generate oxygen.

[0041] The gases produced during off-gas emissions are a mixture of various gaseous substances. The gases produced as battery components decompose are primarily known to include carbon dioxide, carbon monoxide, oxygen, hydrogen, and hydrocarbons (such as methane (CH4), ethene (C2H4), and propane (C3H8).

[0042] In the case of carbon dioxide, it is mainly generated when LiPF6 and the electrolyte decompose at high temperatures, and some is generated together with carbon monoxide due to the reaction of hydrocarbons and oxygen resulting from the decomposition of other elements.

[0043] Hydrogen is produced through a side reaction between lithium and polyvinylidene fluoride (PVDF) or carboxymethyl cellulose (CMC), binders used in the cathode material manufacturing process.

[0044] Among hydrocarbons, C2H4 is generated from the decomposition of the SEI layer and side reactions between the EC electrolyte and lithium, and CH4, C2H6, and C3H6 are generated from side reactions between the DMC electrolyte and lithium.

[0045] Gases generated during thermal runaway are readily generated even during simple battery operation, and this has been confirmed in numerous studies. Oxygen gas is generated from cathode decomposition in the high-voltage range, carbon dioxide gas is generated from electrolyte side reactions, and hydrocarbon and hydrogen gas are generated during the formation and decomposition of the initial SEI layer.

[0046] Among the gases generated, carbon dioxide gradually increases in quantity as charging and discharging continues, as electrolyte side reactions in the high-voltage region also persist. Therefore, it will be difficult to distinguish between carbon dioxide generated during actual operation and that generated due to thermal runaway.

[0047] Hydrocarbon and hydrogen gases, on the other hand, are generated during the initial SEI layer formation and remain constant throughout the battery's operation. They are also expected to be generated during the SEI decomposition process, which begins at the lowest temperature during thermal runaway.

[0048] Therefore, according to one embodiment of the present invention, a hydrocarbon series and hydrogen gas are used as gaseous substances of specific components as detection targets for detecting thermal runaway of a battery.

[0049] Additionally, the initial stage of thermal runaway of a secondary battery is characterized by high temperatures exceeding the battery's heat resistance temperature and resulting material deformation.

[0050] Therefore, monitoring battery deformation can also be a factor in early detection and preemptive action of battery thermal runaway.

[0051] Thermal Runaway Detection System

[0052] Fig. 1 is a conceptual diagram illustrating a battery module, and Fig. 2 is a conceptual diagram illustrating a battery pack. In this embodiment, the battery is a lithium-ion battery.

[0053] As illustrated in Fig. 1, a battery module (1) comprises a casing (2) and a plurality of battery cells (3) arranged inside the casing (2). As illustrated in Fig. 2, a battery pack (10) comprises a plurality of battery modules (11) arranged inside a housing (11).

[0054] In Fig. 1, the inside of the battery module (1) is visible through the casing (2), but this is for convenience of explanation, and in reality, the casing (2) is not transparent. In Fig. 2, the upper half of the housing (11) is separated for convenience of explanation, but in reality, the upper half of the housing (11) is connected to the illustrated lower half, so that the battery module (11) is packed without being exposed inside the housing (11).

[0055] Batteries used in electric vehicles, etc., are generally in the form of a battery pack (10), and the term "battery" generally refers to a battery pack. However, there is also a type in which multiple battery cells are not separately modularized but are arranged inside a housing to form a battery. This type of configuration is ultimately substantially similar to the configuration of the "battery module" of the present specification illustrated in FIG. 1. In other words, the "battery module" and "battery pack" of the present specification can each become a completed "battery" used in an actual product such as an electric vehicle.

[0056] Therefore, in this specification, “early detecting thermal runaway of a battery module” may mean detecting thermal runaway of a battery module, which is a component of a battery pack (10), or may mean detecting thermal runaway of the entire completed battery, depending on the type of battery.

[0057] As illustrated in FIG. 1, a battery thermal runaway detection system for early detection of thermal runaway of a battery module (1) includes a gas sensor module (100) for detecting a gaseous substance included in a mixed gas discharged from a battery module (1), and a processor for processing a signal of the gas sensor module (100).

[0058] The processor may be configured to be integrated into a battery management system (BMS) (300) (see FIG. 2), or may be configured as a separate component capable of communicating with the BMS (300) via wired or wireless communication.

[0059] According to this embodiment, the gas sensor module (100) detects the components of gaseous substances included in the mixed gas discharged from the battery module (1).

[0060] Thermal runaway of the battery module (1) is detected early by detecting whether a gaseous substance of a specific component generated by deterioration of the battery cell (3) is detected by the gas sensor module (100). According to the present embodiment, the gaseous substance of the specific component is a hydrocarbon series and hydrogen gas.

[0061] The gas sensor module (100) may be mounted either inside or outside the casing (2), but according to the present embodiment, in order to minimize the influence of temperature rise of the battery cell (3), the gas sensor module (100) is mounted outside the casing (2).

[0062] An adapter (4) is formed in the casing (2) so that the casing (2) communicates with the inside, and one end of a discharge pipe (102) is connected to the adapter (4). The other end of the discharge pipe (102) is connected to a gas inlet (101) of a gas sensor module (100), so that the inside of the casing (2) and the gas sensor module (100) are in gas communication with each other through the discharge pipe (102).

[0063] According to the present embodiment, a separate hole is formed in the casing (2), an adapter (4) is mounted, and a discharge pipe (102) is connected, but this is not limited thereto. The casing (2) of the battery module (2) has a gap through which gas generated during battery operation can be discharged, and the discharge pipe (102) may be connected to the gap already formed to allow gas to flow into the gas sensor module (100).

[0064] According to the present embodiment, the thermal runaway detection system further includes, in addition to the gas sensor module (100), a strain gauge (200) that detects the amount of deformation of the battery cell (3).

[0065] According to the present embodiment, a strain gauge (200) is attached to each of all battery cells (3) constituting the battery module (1).

[0066] According to the present embodiment, the processor of the thermal runaway detection system determines that a gaseous substance of a specific component is detected by the gas sensor module (100) and that thermal runaway of the battery module (1) is in progress. Alternatively, according to the present embodiment, the processor of the thermal runaway detection system may determine that thermal runaway of the battery module (1) is in progress when a condition is met in which a gaseous substance of a specific component is detected by the gas sensor module (100) and a deformation of the battery cell (3) is detected by the strain gauge (200).

[0067] When a plurality of battery modules (1) constitute a battery pack (10), a gas sensor module (100) may be mounted on each of the plurality of battery modules (1), but according to the present embodiment, as shown in FIG. 2, one gas sensor module (100) may be formed on the battery pack (10).

[0068] In the latter case, a discharge pipe (102) is connected to each of the plurality of battery modules (1), and the gas sensor module (100) is connected to all of the plurality of discharge pipes (102) connected to each of the plurality of battery modules (1). Accordingly, the gas sensor module (100) is connected to all of the plurality of battery modules (1).

[0069] As illustrated in FIG. 2, according to the present embodiment, a plurality of discharge pipes (102) connected to each of the battery modules (1) are connected to the gas inlet (103) of the gas sensor module via a valve (103).

[0070] According to one embodiment, the processor controls the valve (103) so that the mixed gas discharged from the plurality of battery modules (1) is introduced into the gas sensor module (100) in a certain order.

[0071] <Gas sensor module (100)>

[0072] Fig. 3 illustrates a partial configuration of a gas sensor module (100) according to one embodiment. The gas sensor module (100) has a detection unit (111) and a casing that accommodates the detection unit (111) therein, and the casing is omitted in Fig. 3.

[0073] According to this embodiment, the detection unit (111) of the gas sensor module (100) includes a concentration unit (400), a separation unit (500), and a sensing unit (600) miniaturized and integrated into a portable form and formed on a single substrate (110).

[0074] In addition, a heating wire (401) or an electrode, etc. may be formed on the substrate (110), and a power source (not shown) and a communication device (not shown) may be built into the detection device (110).

[0075] In addition, the detection device (110) may be equipped with a memory that stores information such as a library regarding the time at which a gaseous substance escapes through a separation path (510), as described below, and a processor that compares information detected by the sensor module with the library to derive a result. However, the functions of the memory, processor, etc. as described above may be performed by a separate computer, and the detection device (120) may communicate with a separate computer to send the detection results by the sensor module to the computer for processing.

[0076] According to the present embodiment, the concentration unit (400), the separation unit (500), and the conduits (118, 119) communicating therewith are all deeply etched and formed on the upper surface of a silicon substrate (110) using a deep reactive-ion etching (DRIE) process. Therefore, nano-sized structures can be precisely formed on the substrate (110), thereby miniaturizing the overall size of the detection unit (111). The concentration unit (400), the separation unit (500), and the conduits (118, 119) communicating therewith are simultaneously etched and formed in a concave groove shape on the substrate (110), and a glass upper plate (120) (see FIG. 5) is placed and bonded to block the concave groove, thereby completing a closed upper structure.

[0077] According to this embodiment, the substrate (110) and the upper plate (120) can be strongly bonded to each other by anodic bonding, which is a voltage-based bonding method under atmospheric pressure conditions.

[0078] (Concentrated portion (400))

[0079] Figure 4 is an enlarged view of the concentration unit (400) according to the present embodiment.

[0080] The concentration unit (400) includes a concentration chamber (410) formed as a space with a large volume compared to the pipe connected thereto.

[0081] The concentration chamber (410) has a roughly elongated polygonal shape, including two opposing unidirectional sides extending in the short direction of the concentration chamber (410) and two opposing longitudinal sides extending in the long direction of the concentration chamber (410).

[0082] The unidirectional side is formed by bending roughly in a “v” shape so that the center is away from the longitudinal side, thereby allowing the flow of fluid within the concentration chamber (410) to spread evenly.

[0083] An inlet conduit (112) is formed in the center of one unidirectional side of the concentration chamber (410) to communicate with the concentration chamber (410) and to allow a gas mixture to flow in. An outlet conduit (113) is formed in the center of the other unidirectional side of the concentration chamber (410) to allow gas to escape from the concentration chamber (410).

[0084] The terms "inlet" and "outlet" in this specification are intended to refer to different openings through which fluid can flow into and out of a given pipeline, and are not necessarily limited to fluid flowing into the inlet and flowing out of the outlet. That is, in some cases, fluid may flow into the outlet and flow out of the inlet.

[0085] A plurality of columns (411) are arranged at regular intervals inside the concentration chamber (410). By using a depth reactive ion etching process, a plurality of columns (411) can be formed inside the concentration chamber (410) by preventing some of the columns (411) from being etched when forming the concentration chamber (410).

[0086] The concentration chamber (410) filters and concentrates and stores gaseous substances (700) (see FIG. 7) in the mixed gas. To this end, the interior of the concentration chamber (410) is filled with an adsorbent (412) capable of capturing gaseous substances (700). For example, a material such as a carbon compound, to which gaseous substances (60), which are organic compounds, can be attached and captured by van der Waals forces, may be used as the adsorbent (412).

[0087] The adsorbent (412) may be filled in the concentration chamber (410) in advance before bonding the substrate (110) and the upper plate (200), or may be filled in the concentration chamber (410) by a gas transfer method. In the case of a gas transfer method, a separate introduction pipe (not shown) may be formed to communicate with the concentration chamber (410).

[0088] The gaseous substance introduced into the concentration chamber (410) is captured by the adsorbent (412) and stored in a concentrated state inside the concentration chamber (410).

[0089] In order to discharge the gaseous substance (700) concentrated and stored in the concentration chamber (410) back out of the concentration chamber (410), the bond between the adsorbent (412) and the gaseous substance (700) must be broken, and the detection unit (111) according to this embodiment is equipped with a heating wire (401) that applies heat to the concentration chamber (410).

[0090] The detection unit (111) may be equipped with a terminal that can connect power to the heating wire (401) and a temperature sensor that can measure the temperature rising by the heating wire (401).

[0091] By applying power to the heating wire (401) to generate heat, heat energy capable of dissociating the adsorbent (412) and the gaseous substance (700) can be selectively applied to the concentration chamber (410).

[0092] The outlet pipe (113) of the concentration unit (400) is connected to the separation unit (300) through the pipe (118).

[0093] (Separation section (500))

[0094] As illustrated in FIG. 3, the separation unit (500) includes a long separation path (510). The separation path (510) forms a single fluid flow path, and gaseous substances (700) introduced into the separation path (510) are separated into components while moving along the separation path (510) which has a very long path, and are discharged from the separation path (510) with a time difference.

[0095] According to the present embodiment, in order to ensure that the separation path (510) has a sufficiently long path to separate the gaseous material into components, the separation path (510) is arranged to form a single layer of columns that are arranged in a maze-like shape within a given square space.

[0096] As illustrated in FIG. 3, from the inlet (114) of the separation path (510) in fluid communication with the conduit (130), the separation path (510) extends in a coil shape while bending toward the center of a square space, and then extends again from the center in a coil shape to the outlet (115) of the separation path (510). That is, the path extending in a columnar shape toward the center and the path extending away from the center intersect each other adjacent to each other, thereby maximizing the path length of the separation path (510) in a small space.

[0097] In Figure 3, for convenience of illustration, adjacent paths are sufficiently spaced apart, but the spacing between adjacent paths is formed very closely. By forming the path spacing very closely, for example, a separation path (510) with a cross-sectional area on the order of several nanometers can be extended for approximately 3 meters.

[0098] FIG. 5 schematically illustrates the interior of a separation path (510) according to one embodiment of the present invention.

[0099] As shown in Fig. 5, a separation path (510) is formed in a groove shape on the top of the substrate (110), and a top plate (120) is bonded on the substrate (110) to form a channel of the separation path (510).

[0100] The separation path (510) is a space divided by two opposing walls (channel walls) and a floor, and serves as a path through which gas can flow.

[0101] According to this embodiment, nano-scale nanorods (511) are formed within the separation path (510) to interfere with the flow of gaseous substances within the gas flowing along the separation path (510).

[0102] Figures 6a to 6g are drawings explaining a method of forming a separation path (510).

[0103] According to one embodiment, as shown in FIG. 6a, a substrate (110) which is a silicon wafer is prepared, and a masking layer (130, 140) is formed on the substrate (110).

[0104] According to the present embodiment, first, a hard masking layer (130) is formed on a substrate (110), and a photosensitive agent (PR) is applied on the hard masking layer (130) to form a photosensitive layer (140). In the present embodiment, the hard masking layer (130) is formed by depositing aluminum on the substrate (110).

[0105] The photosensitive agent used to form the photosensitive layer (140) may be any photosensitive agent commonly used in conventional semiconductor processes. In this embodiment, a positive photoresist is used, in which the portion exposed to light through the exposure process dissolves in a developer.

[0106] Next, as shown in FIGS. 6b and 6c, the masking layer (130, 140) is removed for the area where the separation path (510) is to be formed on the substrate (100).

[0107] First, as illustrated in FIG. 6b, a patterned mask (150) is placed to correspond to the position of the sidewall (512) of the separation path (510), and an exposure process is performed to transfer the pattern. Thereafter, the light-exposed reducing agent is dissolved and removed using a developer. Accordingly, the hard masking layer (130) is exposed in the area where the separation path (510) is to be formed.

[0108] Next, as illustrated in FIG. 6c, the photosensitive agent is removed to remove the exposed hard masking layer (130). In this embodiment, the hard masking layer (130) made of aluminum is removed using an aluminum etchant. The hard masking layer (130) remains in the portion covered by the photosensitive layer (140), and the hard masking layer (130) is removed for the exposed portion, i.e., the area where the separation path (510) is to be formed.

[0109] Since the processes described in FIGS. 6a to 6c are already known in semiconductor processes, the secondary processes required for pre- and post-processing of each step are not described in further detail here.

[0110] Next, as shown in FIGS. 6d to 6f, a step of etching a groove in the substrate (110) to form a separation path (510) is performed.

[0111] According to the present embodiment, etching is performed using a deep reactive ion etching (DRIE) process (hereinafter simply referred to as the “etching process”).

[0112] As illustrated in FIG. 6d, when the etching process is performed, a separation path (510) begins to form by forming grooves on the upper surface of the exposed substrate (110). Hereinafter, the portion surrounding the area where nanorods (511) are to be formed within the separation path (510) is defined as a side wall (512) and a bottom (513).

[0113] After a predetermined time from the time the separation path (510) begins to form, the photosensitive layer (140) is removed by an etching process, so that only the hard masking layer (130) remains on the substrate (110).

[0114] As illustrated in FIG. 6e, if the etching process continues, the groove of the substrate (110) is etched more deeply than in FIG. 6d. At this time, the hard masking layer (130) is also etched away by the etching process.

[0115] In the etching process, the material of the masking layer is etched together and blown away into nano particles, and the nano particles (531) accumulate at the bottom (513) of the groove forming the channel (200).

[0116] In this embodiment, as in a typical semiconductor process, exhaust is performed to remove impurities. However, as described below, since the separation path (510) according to this embodiment is very narrow, unlike in a typical semiconductor process, it is understood that nanoparticles (531) accumulate within the separation path (510) due to the lack of smooth exhaust within the separation path (510).

[0117] In this way, nano particles (531) accumulated inside the groove of the separation path (510) act as a micro mask during the etching process.

[0118] Accordingly, as illustrated in FIG. 6f, etching is inhibited in areas where nanoparticles (531) have not settled, and etching is performed at the intended rate in areas where they have not. In other words, a difference in the degree of etching occurs within the separation path (510), and as a result, as illustrated in FIG. 6f, a portion of the substrate (110) remains within the separation path (200) (i.e., sufficient etching has not occurred), and a very large number of nanorods (511) are formed in a form that protrudes from the bottom.

[0119] Finally, when a top plate (120) having a size corresponding to that of the substrate (110) is bonded onto the substrate (110), the step of forming a separation path (510) on the substrate (110) is completed. As described above, the top plate (120) made of glass is bonded to the upper portion of the substrate (110) by anodic bonding.

[0120] Here, since the groove of the separation path (510) is etched to a certain depth before the hard masking layer (130) is etched (see FIG. 6e), the length of the nano rods (511) is characterized by being shorter than the side wall (512). In other words, this means that by controlling the thickness of the hard masking layer (130) and the photosensitive layer (140) to control the etching timing, the overall length of the nano rods (511) can be controlled and formed. In addition, by narrowing the width of the separation path (510) to further inhibit the exhaust of the nano particles (531), the length of the nano rods (511) can be lengthened and the number thereof can be controlled.

[0121] Figure 7 is a schematic diagram showing the interior of a separation path (510).

[0122] According to the present embodiment, the interior of the separation path (510) is coated with a porous material (520) to which a gaseous substance can be attached. For example, the porous material (520) may be a porous polymer such as PDMS.

[0123] The porous material (520) may be coated before the substrate (110) and the upper plate (120) are bonded (see FIGS. 6f and 6g), or may be coated by gas flow through a separate introduction tube (not shown).

[0124] Although not shown in detail in Fig. 7, the porous material (520) is coated not only on the inner surface of the separation path (510) but also on the surface of the nanorods (511).

[0125] Gaseous substances, which are mostly organic compounds, are attached to the porous polymer by van der Waals forces. Unlike the conventional technology, since the porous substances are also coated on the nanorods (511), a large number of gaseous substances are attached to the nanorods (511) (of course, they are also attached to the inner surface of the separation path (510). At this time, when a carrier gas flows into the separation path (510), the gaseous substances attached to the nanorods (511) and the inner surface are separated by the force of the carrier gas, flow for a certain distance, lose mobility, and are attached again at a different location, repeating this process.

[0126] Since the gaseous substances have different masses and van der Waals forces acting on the porous material (520) depending on their components, as illustrated in FIG. 7, the gaseous substances (700) of different components are attached to the porous material (520) coated on the surface of nanorods (511) and then separated and flow at different frequencies and distances. That is, the gaseous substances move at different movement speeds within the separation path (510) depending on their components. For example, among the first material (11) indicated by a triangle and the second material (12) indicated by a circle, the movement speed of the second material (12) is faster.

[0127] According to the present embodiment, since the separation path (510) has a long path of about 3 m, the gaseous substances injected into the inlet (114) of the separation path (510) have their movement distances equalized for each component while traveling along the long path, and are clumped together by component and discharged through the outlet (115) of the separation path (510). Since the gaseous substances have different movement speeds depending on their components, the gaseous substances are separated by component and discharged through the outlet (115) of the separation path (510) with a time difference. That is, without applying electricity or other work, the gaseous substances are separated by component and discharged with a time difference simply by causing the hazardous substances to travel through the separation path (510).

[0128] The gaseous substance (700) that sequentially exits the exit of the separation path (510) sequentially flows into the sensing unit (600) through the inlet (117) and is detected by the sensing unit (600).

[0129] The formation method and characteristics of the separation unit (500) described above may be referred to in the disclosure of Patent Application No. 10-2023-0016961 filed by the applicant of the present application on February 8, 2023.

[0130] (Sensing unit (600))

[0131] Fig. 8 is a drawing explaining the configuration and sensing principle of a sensing unit (600) according to one embodiment.

[0132] The sensing unit (600) includes a flow path (610) through which a gaseous substance (700) flowing from a separation path (510) of a separation unit (500) flows, and a photoionization (PID) sensor (620) that applies ultraviolet (UV) rays to the gaseous substance (700) flowing in the flow path (610) to measure a voltage change due to electrons dissociated from the gaseous substance (700).

[0133] Specifically, when UV light is applied to a substance such as an organic compound, electrons are released, generating an electric potential. The higher the concentration of the substance, the higher the detected potential, allowing the concentration of the substance to be calculated.

[0134] Through experiments, the time for exiting the separation path (510) according to the composition of the gaseous substance (700) can be obtained in advance, and a library for the time for each gaseous substance (700) to exit the separation path (510) can be created.

[0135] Since gaseous substances (711, 712, 713, 714) of different components sequentially flow through the separation path (510), they flow through the flow path (610) in that order, and by checking the time at which the potential value significantly increases through the sensor (620), the components of the gaseous substances can be known, and the concentration of the gaseous substances can also be obtained through the potential value.

[0136] Figure 9 is a graph showing the detection results detected through the sensing unit (600).

[0137] As shown in Fig. 9, it can be confirmed that a sharp peak occurs in which the potential value rapidly increases at a given time.

[0138] The components of the gaseous substances detected at that time are already specified, for example, the substance of peak a may be ethene (C2H4) and pyridine, and the substance of peak b may be methane (CH4).

[0139] In addition, it is possible to analyze how much of a gaseous substance (60) of a certain component is included in the gas mixture (6) discharged from the processing device (1) through the potential value according to the component of the gaseous substance.

[0140] The configuration of the sensing unit (600) is not limited to the embodiment of FIG. 8, and any sensor configuration for detecting gaseous substances that move separately by component can be used as the sensing unit (600).

[0141] Fig. 10 illustrates the configuration of a sensing unit (600) according to another embodiment.

[0142] Referring to FIG. 10, a sensing unit (600) according to the present embodiment may include an electrode pattern (630), a carbon structure (640) positioned on the electrode pattern (630) and including pores capable of adsorbing gas particles, and a measuring unit (650) electrically connected to the electrode pattern (630) to measure electrical characteristics (e.g., resistance) of the electrode pattern (630). In the present specification, a unit is intended to include hardware means for achieving a specific function and / or software means stored and executed by such hardware means.

[0143] In one embodiment, the electrode pattern (630) has an electrode shape formed by a pair of interlocking comb-tooth structures (631, 632). Since the carbon structure (640) is electrically connected to the electrode pattern (630) by being positioned on the electrode pattern (630), when gas particles are adsorbed on the carbon structure (640), the electrical characteristics of the electrode pattern (630), such as the resistance between each comb-tooth structure (631, 632) of the electrode pattern (630), change.

[0144] Although not shown in the drawing, the sensing unit (600) according to one embodiment may be positioned on a carbon structure (640) and may further include a bonding material capable of imparting selectivity to gas particles, such as molybdenum dioxide (MoS2), zinc oxide (ZnO2), tin oxide (SnO2), or tungsten oxide (WO3), or a layer made of such a bonding material. For example, the bonding material may be positioned on the carbon structure (640) in the form of one or more quantum dots.

[0145] When the sensing unit (600) is exposed to a gaseous substance, gas particles of the gaseous substance are adsorbed to the carbon structure (640), thereby causing a change in the electrical resistance between the comb structures (631, 632) of the electrode (630). The measuring unit (650) is electrically connected to the electrode pattern (630) through a wire or the like, and can detect surrounding gas particles by measuring the change in resistance of the electrode pattern (630).

[0146] The carbon structure (640) according to the present embodiment has a characteristic that, when exposed to a specific gas particle, the gas particle is adsorbed into a void such as a lattice defect of the carbon structure (640), causing a change in electrical characteristics (e.g., resistance), as it includes a portion with an imperfect arrangement such as a dangling bond, like graphene. Therefore, a gas sensor capable of detecting a gaseous substance can be implemented using this.

[0147] That is, when gas particles are combined with the carbon structure (640), the resistance between the comb structures (631, 632) of the electrode (630) changes, so that the measuring unit (25) can detect the presence of gas and / or the concentration of gas using this. In one embodiment, the change in resistance of the electrode pattern (632) due to the gas particles adsorbed on the carbon structure (640) may vary depending on the type of gas to be measured, and the measuring unit (650) can store data on the presence of gas and / or the gas concentration value according to the change in resistance for each type of a plurality of gases in advance and use this to measure the presence and / or the concentration of gas existing around the carbon structure (640).

[0148] For example, the measuring unit (25) measures nitrogen oxides (NO) such as nitrogen dioxide (NO2). x ) is present around the gas sensor, nitrogen oxides (NO x) are pre-stored for the resistance value of the electrode pattern (20) or the change in the resistance value when these gas particles are adsorbed on the carbon structure (30') according to the concentration, and by comparing the resistance value of the currently measured electrode pattern (20) or the change thereof with the pre-stored data according to the concentration, nitrogen oxide (NO x ) can be generated as output values ​​for the presence and / or concentration.

[0149] Carbon structures are created by carbonizing photoresist, such as SU-8, or other different carbon materials using an energy-emitting means, such as a carbon dioxide (CO2) laser. The carbon structures may include carbon compounds, graphene, and / or graphene oxide, formed by carbon-carbon bonds. Furthermore, the carbon structures may not only include structures in which these materials are arranged in a planar direction, but may also have a three-dimensional arrangement in which the arrangement of the materials extends in the vertical direction. These carbon structures are not only porous but also contain defects in the arrangement, such as dangling bonds, which allow gas particles to be adsorbed in the pores on or within the carbon structures.

[0150] The manufacturing and characteristics of the sensor using the carbon structure described above may be referred to in the disclosure of Patent Application No. 10-2023-0013604 filed by the applicant of the present application on February 1, 2023.

[0151] Strain Gauge (200)

[0152] Referring again to FIG. 1, the strain gauge (200) is a measuring device that measures deformation when an attached object is deformed.

[0153] The strain gauge (200) is attached to the battery cell (3) using an adhesive, and when the alloy wire is deformed in the tensile direction due to deformation of the battery cell (30), the electrical resistance increases due to a decrease in cross-sectional area according to an increase in length, and by measuring the increase, the deformation of the battery cell (3) is measured.

[0154] The strain gauge (200) may be a conventionally known strain gauge, or a temperature-insensitive strain gauge that detects only the shape deformation of the battery cell (3) without being affected by temperature changes may be used.

[0155] <Operation of the thermal runaway detection system>

[0156] The processor causes the mixed gas generated inside the battery module (1) to flow into the gas sensor module (100).

[0157] At this time, in the case of a battery pack (10) equipped with a plurality of battery modules (1) as shown in FIG. 2, the processor controls the valve (103) so that the mixed gas generated inside each battery module (1) sequentially flows into the gas sensor module (100) with a time difference from the plurality of battery modules (1). The time difference at this time may be the time interval during which the mixed gas of one battery module (1) is concentrated in the concentration unit (400) of the gas sensor module (100) and then flows out to the separation unit (500).

[0158] The processor, through the gas sensor module (100), separates and detects gaseous substances in the mixed gas by component, and determines whether a gaseous substance of a predetermined specific component, such as a hydrocarbon series, is detected.

[0159] At this time, a threshold value for the concentration of a specific component gaseous substance is set, and if a gaseous substance of a specific component exceeding the threshold value is detected, the processor may determine that a thermal runaway of the battery is in progress.

[0160] However, since there is a possibility that a large amount of a gaseous substance of a specific component may be temporarily detected depending on the state of use of the battery, the processor checks whether deformation of the battery cell (3) is detected from a plurality of strain gauges (200).

[0161] At this time, the processor can identify the battery cell (3) in which deterioration is progressing by identifying the strain gauge (200) that has detected deformation among the strain gauges (200) attached to each of the plurality of battery cells (3).

[0162] In this case, if both conditions are met, in which a gaseous substance of a specific component is detected above a threshold value by the gas sensor module (100) and in which deformation of the battery cell (3) is detected by the strain gauge (200), the processor determines that thermal runaway of the battery module (100) is in progress.

[0163] Accordingly, the processor notifies the BMS (300) of the progress of thermal runaway, and the BMS (300) cuts off power to prevent power from being supplied to the battery module, thereby preventing the occurrence of thermal runaway. In addition, the BMS (300) notifies the administrator of the fact, thereby prompting maintenance / replacement of the battery module.

[0164] According to the battery thermal runaway detection system according to the present embodiment, the possibility of battery thermal runaway can be detected early and quickly in real time.

Claims

1. A battery thermal runaway detection system for early detection of thermal runaway of a battery module having a casing and a plurality of battery cells arranged inside the casing, A gas sensor module that detects gaseous substances contained in a mixed gas discharged from the above battery module, Includes a processor that processes the signal of the gas sensor module, A battery thermal runaway detection system characterized in that thermal runaway of the battery module is detected early by whether the gaseous substance is generated inside the battery module and detected by the gas sensor module.

2. In paragraph 1, The above gas sensor module detects the components of gaseous substances contained in the mixed gas, A battery thermal runaway detection system characterized in that thermal runaway of the battery module is detected early by determining whether a gaseous substance of a specific component is generated inside the battery module and detected by the gas sensor module.

3. In paragraph 1, A battery thermal runaway detection system, characterized in that the gas sensor module is disposed outside the casing and communicates with the inside of the casing through a discharge pipe.

4. In paragraph 3, Multiple battery modules form a battery pack, A battery thermal runaway detection system characterized in that the gas sensor module is connected to a plurality of discharge pipes connected to each of the plurality of battery modules and communicates with all of the plurality of battery modules.

5. In paragraph 4, The above plurality of discharge pipes are connected to the gas inlet of the gas sensor module via a valve, A battery thermal runaway detection system characterized in that the processor controls the valve so that the mixed gas discharged from the plurality of battery modules is injected into the gas sensor module in a certain order.

6. In paragraph 2, Further comprising a strain gauge for detecting the amount of deformation of the battery cell, A battery thermal runaway detection system, characterized in that when a condition is met in which a gaseous substance of the specific component is detected by the gas sensor module and a deformation of the battery cell is detected by the strain gauge, the processor determines that thermal runaway of the battery module is in progress.

7. In paragraph 6, When the gaseous substance of the specific component is detected by the gas sensor module, A battery thermal runaway detection system characterized in that it determines whether deformation of the battery cell is detected by the strain gauge.

8. In paragraph 6, A battery thermal runaway detection system characterized in that a plurality of strain gauges are attached to each of the plurality of battery cells.

9. In paragraph 2, A battery thermal runaway detection system characterized in that the gas sensor module detects gaseous substances contained in a mixed gas discharged from the battery module by separating them by component.

10. In paragraph 9, The above gas sensor module, A concentrator for filtering and concentrating and storing gaseous substances contained in the above mixed gas, A separation unit that separates gaseous substances flowing from the above-mentioned concentration unit by component; A battery thermal runaway detection system characterized by including a sensing unit that detects gaseous substances leaking from the above separation unit.

11. In paragraph 10, The above separation unit includes a separation path that allows the gaseous substance to move at different speeds inside according to its component, and to be separated by component and discharged with a time difference. A battery thermal runaway detection system characterized in that the sensing unit detects gaseous substances that have escaped the separation path with a time difference.

12. In paragraph 11, A battery thermal runaway detection system characterized in that nano-scale nanorods that interfere with the flow of gaseous substances flowing through the separation path are formed within the separation path.

13. In paragraph 10, The above sensing unit, Electrode pattern and, A carbon structure positioned on the above electrode pattern and having pores into which gas particles can be adsorbed, A thermal runaway detection system characterized by comprising a measuring unit electrically connected to the electrode pattern and configured to detect the gas particles by measuring a change in the electrical characteristics of the electrode pattern when the carbon structure is exposed to the gas particles.

14. In paragraph 10, A battery thermal runaway detection system characterized in that the sensing unit detects the gaseous substance by applying ultraviolet rays to the gaseous substance flowing out from the separation unit and measuring a voltage change caused by electrons dissociating from the gaseous substance.

15. In paragraph 10, A battery thermal runaway detection system, characterized in that the above concentration unit, the separation unit, and the sensor unit are formed on a single substrate.

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