System and method for detecting whether battery is abnormal

Abstract

The present invention relates to a system and a method for detecting whether a battery is abnormal. The system for detecting whether a battery is abnormal according to the present invention is a system for detecting whether a battery is abnormal by using a sensor for detecting battery swelling, wherein the sensor comprises: a conductive elastic body deformable by an external force; and an electrode connected to the conductive elastic body, wherein, when the conductive elastic body is deformed by an external force, the sensor measures a change in at least one of resistance (R), inductance (L), and capacitance (C) of the conductive elastic body transmitted through the electrode.

Description

Battery Abnormality Detection System and Detection Method

[0001] The present invention relates to a system and method for detecting abnormalities in a battery. More specifically, it relates to a system and method for detecting abnormalities in a battery by detecting swelling of the battery.

[0002] The present invention relates to project number 1425176954 and project number 00257362, which were carried out with funding from the Ministry of SMEs and Startups and support from the Korea Technology Information Promotion Agency for SMEs.

[0003] Batteries used in electric vehicles require high output and large capacity. Consequently, electric vehicle batteries are applied as medium-to-large battery packs in which multiple battery cells are electrically connected. Medium-to-large battery packs have a configuration in which multiple battery modules are housed within a battery case and electrically connected. In medium-to-large battery packs, it is essential to provide means for preventing and controlling overcharging, over-discharging, and overcurrent during use. Furthermore, it is essential to provide various safety and control devices to prevent ignition or explosion caused by heat generation or chain reaction side effects.

[0004] Although efforts are being made to prevent the above-mentioned abnormal phenomena by using control means for electric vehicle batteries, there is always a possibility that failures or abnormalities may occur in the battery due to physical shocks or vibrations applied from the outside or internal problems. Overloading or swelling of the battery can increase pressure inside the battery case, potentially leading to fire and explosion. In particular, as the number of electric vehicle fires is increasing every year, and once a battery begins to run wild, it is very difficult to extinguish and poses a risk of the vehicle being completely burned, there is a need for a system that detects abnormal conditions, such as swelling, before the battery runs wild.

[0005] The present invention aims to provide a battery abnormality detection system and a detection method capable of detecting an abnormal state before thermal runaway of the battery.

[0006] In addition, the present invention aims to provide a battery abnormality detection system and a detection method that can prevent fire accidents caused by batteries and enable preemptive measures.

[0007] However, these tasks are exemplary and do not limit the scope of the invention.

[0008] The above objective of the present invention is achieved by a battery abnormality detection system that detects the presence or absence of an abnormality in a battery using a sensor that detects battery swelling, wherein the sensor comprises: a conductive elastic body deformable by an external force; and an electrode connected to the conductive elastic body; and when the conductive elastic body is deformed by an external force, the system measures a change in at least one of R (resistance), L (inductance), and C (capacitance) of the conductive elastic body transmitted through the electrode.

[0009] In addition, according to one embodiment of the present invention, the sensor is positioned on the side or inside of a battery cell, or on the side or inside of a case of a battery pack including a plurality of batteries, and when the battery cell or the battery pack swells, an external force can be applied to the conductive elastic body to cause deformation.

[0010] In addition, according to one embodiment of the present invention, a control unit connected to the electrode and receiving signals for R, L, and C may be further included.

[0011] In addition, according to one embodiment of the present invention, the conductive elastomer comprises a conductive portion having conductivity and a non-conductive portion having non-conductivity, and the electrode comprises at least an electrode for measuring resistance, and the electrode for measuring resistance may be connected to the conductive portion.

[0012] In addition, according to one embodiment of the present invention, the electrode further includes a capacitance measuring electrode, and the capacitance measuring electrode may be connected to the non-conductive part.

[0013] In addition, according to one embodiment of the present invention, the sensor comprises a plurality of units, and the battery comprises a plurality of battery cells. If an abnormal pressure increase outside the normal pressure increase range is detected during the charging of each battery cell, it can be determined that swelling has occurred in the cell.

[0014] The above-mentioned sensor comprises a plurality of units, the battery comprises a plurality of battery cells, each of the above-mentioned sensors is placed in each of the above-mentioned battery cells, the Vin and Vc of the sensors are connected in parallel with the battery cells, and the control unit can determine that a specific swollen cell is abnormal if a time constant different from that of the remaining cells is measured in that specific cell.

[0015] In addition, according to one embodiment of the present invention, the control unit measures the degree of volume expansion during charging as an external force applied to the conductive elastic body during the process of repeating charging and discharging of a specific battery cell, sets a normal volume range after charging, and can determine that swelling of the specific battery cell occurs if a value outside the normal volume range is measured in the specific battery cell.

[0016] In addition, according to one embodiment of the present invention, the sensor comprises a plurality of units, and the battery comprises a plurality of battery cells. The control unit measures the average value of the degree of volume expansion during charging as an external force applied to the conductive elastic body during the process of the plurality of battery cells repeatedly charging and discharging, sets a normal volume range after charging, and if a value outside the normal volume range is measured in a specific battery cell, it can be determined that the specific battery cell is swelling.

[0017] In addition, according to one embodiment of the present invention, the control unit compares a measurement value at a first point in time in the specific battery cell with a measurement value at a second point in time after the first point in time, and if the measurement value increases, it can cut off the power supply to the battery.

[0018] In addition, according to one embodiment of the present invention, the conductive elastomer may include a foam, a sponge, a pad, or a film.

[0019] In addition, according to one embodiment of the present invention, the sensor further comprises a magnetic elastic body, and when the magnetic elastic body is deformed by an external force, a magnetic field of a different strength than before deformation can be applied to the conductive elastic body.

[0020] In addition, according to one embodiment of the present invention, the conductive elastomer may comprise a foam comprising any one of a sponge, a compression pad, a film, and a polymer; and a conductive material comprising at least one of carbon fiber, graphene, MXene, graphite, carbon black, and a conductive polymer.

[0021] In addition, according to one embodiment of the present invention, a hole penetrating one side of the conductive part and the other side opposite to the one side is formed, and at least a portion of the electrode may be disposed on the one side and the other side of the hole.

[0022] In addition, according to one embodiment of the present invention, when an external force applied to the conductive part exceeds a threshold value, an electrode on one surface and an electrode on the other surface come into contact within the hole, causing a short circuit, and the control unit can detect a discontinuous decrease in resistance caused by the short circuit and determine swelling of the battery.

[0023] Furthermore, the above objective of the present invention is achieved by a method for detecting the presence or absence of an abnormality in a battery using a sensor that detects battery swelling, comprising: (a) providing a sensor comprising: a conductive elastic body deformable by an external force; and an electrode connected to the conductive elastic body; (b) placing the sensor on the side or inside of a battery cell, or on the side or inside of a case of a battery pack comprising a plurality of batteries; and (c) measuring a change in at least one of R (resistance), L (inductance), and C (capacitance) of the conductive elastic body transmitted through the electrode when the conductive elastic body is deformed by an external force.

[0024] According to the present invention configured as described above, there is an effect of detecting an abnormal condition before thermal runaway of the battery.

[0025] In addition, according to the present invention, there is an effect of preventing fire accidents caused by batteries and enabling preemptive measures.

[0026] In addition, according to the present invention, the sensor can be applied to various fields such as tactile systems in the robotics field, control systems for prosthetic arms / legs, and user feedback systems for rehabilitation robots.

[0027] Of course, the scope of the present invention is not limited by these effects.

[0028] FIG. 1 is a schematic diagram showing elements capable of detecting changes during battery swelling according to one embodiment of the present invention.

[0029] FIG. 2 is a schematic diagram illustrating the principle of measuring battery swelling according to one embodiment of the present invention.

[0030] FIGS. 3 and 4 are schematic diagrams showing the arrangement of a sensor in a battery according to various embodiments of the present invention.

[0031] FIG. 5 is a schematic diagram showing the wiring configuration of a sensor for a plurality of battery cells according to one embodiment of the present invention.

[0032] FIG. 6 is a schematic diagram showing a battery abnormality detection scenario during charging according to one embodiment of the present invention.

[0033] FIG. 7 is a schematic diagram illustrating a battery abnormality detection scenario during driving or parking according to an embodiment of the present invention.

[0034] FIG. 8 is a diagram showing changes in conductivity and repulsive force due to compression of a conductive elastic body according to one embodiment of the present invention.

[0035] FIG. 9 is a schematic diagram showing a sensor according to a first embodiment of the present invention.

[0036] FIG. 10 is a schematic diagram showing a sensor according to a second embodiment of the present invention.

[0037] FIG. 11 is a schematic diagram showing a sensor according to a third embodiment of the present invention.

[0038] FIG. 12 is a schematic diagram of a parallel connection wiring configuration using the sensors of FIG. 10 to FIG. 11.

[0039] FIG. 13 is a schematic diagram showing a coil portion used in a sensor according to one embodiment of the present invention.

[0040] FIG. 14 is a schematic diagram showing a sensor according to a fourth embodiment of the present invention.

[0041] FIG. 15 is a schematic diagram showing a sensor according to the fifth embodiment of the present invention.

[0042] FIG. 16 is a schematic diagram showing a sensor according to the sixth embodiment of the present invention.

[0043] FIG. 17 is a schematic diagram showing the measurement circuit of the pressure / distance sensor of FIG. 14 to FIG. 16.

[0044] FIGS. 18 and 19 are schematic diagrams showing sensor arrangement forms according to various embodiments.

[0045] FIG. 20 is a photograph showing a sensor with a conductive elastic applied according to one embodiment of the present invention.

[0046] FIGS. 21 to 23 are schematic diagrams showing the characteristics of sensors according to conductive materials of conductive elastomers according to various embodiments of the present invention.

[0047] FIGS. 24 to 25 are schematic diagrams showing the charge and discharge characteristics of a conductive elastomer according to a conductive material according to various embodiments of the present invention.

[0048] FIG. 26 is a schematic diagram showing the process of detecting battery swelling during charging and discharging according to one embodiment of the present invention.

[0049] FIG. 27 is a schematic diagram showing a sensor according to an additional embodiment of the present invention.

[0050] FIGS. 28 to 29 are schematic diagrams showing short-circuit generation characteristics according to the hole size of the sensor of FIG. 27.

[0051] FIGS. 30 to 31 are schematic diagrams showing various embodiments of the sensor of the present invention.

[0052] <Explanation of Symbols>

[0053] 50: Coil part

[0054] 70: Elastomer

[0055] 100: Sensor

[0056] 110: Conductive part

[0057] 120: Non-transmitting Father

[0058] 130: Electrode for resistance measurement

[0059] 140: Electrode for capacitance measurement

[0060] 150: Spiral coil

[0061] 160: Insulating flexible film

[0062] 170: Metal film part

[0063] 180: Magnetic elastomer

[0064] C: cell

[0065] EL: Electrode

[0066] R: Jelly roll

[0067] TH: hole

[0068] Refer to the accompanying drawings, which illustrate embodiments by way of example. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that various embodiments of the invention are different but need not be mutually exclusive. For example, specific shapes, structures, and characteristics described herein with respect to one embodiment may be implemented in other embodiments without departing from the spirit and scope of the invention. It should also be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the following detailed description is not intended to be limiting, and the scope of the invention is limited only by the appended claims, including all equivalents to those claimed therein, provided appropriately described. Similar reference numerals in the drawings refer to the same or similar functions across various aspects, and lengths, areas, thicknesses, etc., and shapes may be exaggerated for convenience.

[0069] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings in order to enable a person skilled in the art to easily practice the present invention.

[0070] Conventional methods for detecting battery anomalies utilize a single voltage, temperature, gas, or pressure sensor within the battery pack. Among these, pressure and gas detection methods offer advantages over voltage and temperature detection methods, including higher reliability, lower cost, and the ability to detect issues while the vehicle is parked. However, conventional pressure detection methods have a problem in that detection is only possible when gas leaks out of the case, as at least one battery cell has already been torn by the time the pressure threshold is exceeded. In other words, since the swelling stage cannot be detected in advance, there were issues that made fire prevention and other preventive measures impossible.

[0071] FIG. 1 is a schematic diagram showing elements capable of detecting changes during battery swelling according to one embodiment of the present invention.

[0072] FIG. 1 (a) shows a pouch-type / prismatic / cylindrical battery (10) comprising a plurality of cells (12). In the battery (10), a sensing means (sensor) can be installed on the inner wall of the case (11) and around the cells (12). FIG. 1 (b) shows a prismatic / cylindrical battery (20) comprising a jelly roll (23). In the battery (20), since the cell (22) wall is rigid and the jelly roll (23) has a rolled shape, a sensing means (sensor) can be installed on the inner wall of the cell (22).

[0073] Referring to the right-hand diagram of FIG. 1 (a) and (b), elements that change due to the swollen cell (12', 22') can be detected. For example, the shape (curvature, profile) of the cell or case, applied force / pressure, distance between cells / distance between cases, pressure / force of the jelly roll inside the cell, separation distance, curvature, displacement (strain), displacement of the cell or case, etc. can be detected.

[0074] The detection methods by measurement principle (simple element) are as follows.

[0075] In a resistance (R) measuring sensor, the resistance changes as the thickness and shape of the elastic material contained within the sensor change. When the measurement target is in the form of foam, the resistance changes according to pressure / force and the gap between cells; when it is in the form of a film, the resistance can be measured according to changes in length such as curvature and case strain.

[0076] In a capacitance (C) measuring sensor, the capacitance changes as the thickness and shape of the elastic material included in the sensor change. When the measurement target is in the form of foam, the capacitance changes according to pressure / force and the gap between cells; when it is in the form of film, the capacitance changes according to pressure / force and the sensor thickness.

[0077] In a magnetic field measurement sensor, the strength of the magnetic field inside, on the surface, and near the elastic body changes as the thickness and shape of the elastic body contained within the sensor change. When the measurement target is in the form of foam, it can measure changes in the magnetic field according to pressure / force and the gap between cells; when the target is in the form of film, it can measure changes in the magnetic field according to pressure / force, the gap between cells, curvature, and case displacement.

[0078] FIG. 2 is a schematic diagram showing the battery swelling measurement principle according to one embodiment of the present invention, showing a detection method for each measurement principle (multiple elements).

[0079] Figure 2 (a) shows the RC type (series, parallel). Time constant R(t) = 9.56 X 10⁻⁶ 5 XT -2.684 Since [or τ=RC], detection is performed by comparing the normal τ and abnormal τ through changes in C and R of the elastic body (sensor) caused by external force (force applied by the cell to the sensor) -> changes in τ -> normal τ and abnormal τ. In particular, in the case of RC type parallel, detection is possible even if the τ value changes in only one cell, so there is an advantage in that the wiring structure can be simplified.

[0080] Figure 2 (b) shows the RL type (series, parallel). Time constant R(t) = 9.56 X 10⁻⁶ 5 XT -2.684 Since [or, τ=L / R], detection is performed by comparing normal τ and abnormal τ through changes in L and R of the elastic body (sensor) caused by external force (force applied by the cell to the sensor) -> changes in τ -> normal τ and abnormal τ. Even in the case of RL-type parallel, detection is possible even if the τ value changes in only one cell, so there is an advantage of simplifying the wiring structure and an advantage that adding wiring does not affect the BMS (battery monitoring system).

[0081] Figure 2 (c) shows the LC type (series, parallel). Resonant frequency ω0 = 1 / (LC) 1 / 2 Therefore, detection is performed by comparing the normal ω and abnormal ω values, and the change in L and C values ​​of the elastic body (sensor) due to the external force (force applied by the cell to the sensor) -> the change in ω value.

[0082] In addition to the forms of Figures 2 (a) to (c), RLC and RC / LC / RL mixed types are also applicable.

[0083] The measurement count / batch / connection detection method can be considered as follows.

[0084] For example, the number of placement sensors per cell can be single (one point within the cell) or multiple (multiple points within the cell, profile).

[0085] In addition, as an example, the electrode placement structure within the sensor can be configured as a stacked type (bottom electrode + elastic body + top electrode), a planar type (electrode layer + elastic body), or an insertion type (electrode inserted into the elastic body).

[0086] In addition, as an example, sensors can be connected in individual (connecting sensor signals individually to the BMS), serial (connecting serially to the BMS), parallel (connecting parallelly to the BMS), or mixed (connecting to the BMS by mixing individual, serial, and parallel connections).

[0087] FIGS. 3 and 4 are schematic diagrams showing the arrangement of a sensor in a battery according to various embodiments of the present invention. Figures 3 and 4 (a) and (b) each correspond to (a) a pouch-type / prismatic / cylindrical battery (10) including a plurality of cells (12) and (b) a prismatic / cylindrical battery (20) including a jelly roll (23) as described above in FIG. 1.

[0088] Referring to FIG. 3, possible sensor locations for resistance / capacitance / voltage measuring sensors are indicated in gray shading. Force / distance can be sensed from the front as in the first figure of each (a) and (b), curvature / displacement can be sensed from the front as in the second figure, or profile can be sensed from the side as in the third figure.

[0089] Referring to FIG. 4, the positions of the magnetic elastomer and magnetic field sensing sensor that can be placed for the magnetic field measuring type sensor are indicated in gray and black, respectively. Force / distance can be sensed from the front as in the first figure of each (a) and (b), curvature / displacement can be sensed from the front as in the second figure, or a profile can be sensed from the side as in the third figure.

[0090] As an example of a magnetic field measuring sensor, the Hall sensor is described as follows.

[0091] First, an electric current (Iref) flows through a conductor, and free electrons move in the opposite direction of the current. When a magnetic field (Bp) is applied or brought close to it, the moving free electrons are subjected to a Lorentz force according to Fleming's left-hand rule due to the Hall effect, causing their direction of movement to bend. A potential difference is generated by the Hall effect, and a Hall voltage (Vhall) is formed in the installed circuit due to this electromotive force. If the direction of the current changes or the direction of the magnetic field changes, the Hall effect and Hall voltage also become opposite accordingly.

[0092] The Hall voltage is V hall = (I ref XB pIt can be calculated as ) / (tne). For example, Iref ~ 1 mA, Bp ~ 600 Gauss, n ~ 10 22 m -3 (doped silicon, N d ~ 10 16 ), when t ~ 100 nm, VHall ~ 60 mV may be observed.

[0093] The magnetic field applied from the magnetic elastomer to the magnetic field sensing sensor can change as the distance between the magnetic elastomer and the circuit of the magnetic field sensing sensor approaches or moves farther, and consequently, a Hall voltage may be generated. If an external force is applied to the magnetic elastomer and a portion of it is deformed, the distance to the circuit of the magnetic field sensing sensor decreases, and a magnetic field may be applied. Since the magnetic elastomer can exhibit a magnetic field while in a magnetized state, the strength of the applied magnetic field increases as it approaches the circuit of the magnetic field sensing sensor, thereby increasing the Hall voltage (V Hall ) can increase. Thus, the pressure applied to the magnetic elastic body and the output signal (V) of the circuit part of the magnetic field sensing sensor. Hall A correlation occurs between ). The circuit part has Hall voltage (V Hall The pressure applied to the magnetic elastic body can be detected by measuring the size of ).

[0094] According to one embodiment, the material of the sensor is as follows.

[0095] Resistance, voltage, and capacitance sensing sensors (film type, foam type) may utilize piezoresistive, capacitive, or piezoelectric materials. For example, polymers (silicon, polyurethane (PU), hydrogel, etc.), conductive particles (conductive fiber, carbon black, silver nanowire, graphene, etc.), and magnetostrictive materials (CoFe alloy, etc.) may be used. Composite materials that satisfy the existing compression-force dynamic (CFD) characteristics while maintaining conductivity can be selected or formulated, and process conditions may be considered. As auxiliary materials, flexible substrates / electrodes (polyethylene terephthalate (PET), polyimide (PI), etc.), metal electrodes or conductive materials (metal nanowires, graphene, MXene, graphite, carbon black, carbon fiber, nano / micro particles, etc.), and insulating materials (cell-to-cell short-circuit prevention, mica, PI film, etc.) may be used.

[0096] Magnetic elastomers and magnetic field sensing sensors (film type, foam type) can use materials such as polymers, magnetic particles (hard magnets such as NdFeB, Ferrite, etc., and soft magnets such as carbonyl iron particles (CIP), etc.). As auxiliary materials, flexible substrates / electrodes (PET, PI, etc.), metal electrodes or conductive materials (metal nanowires, graphene, MXene, graphite, carbon black, carbon fiber, nano / micro particles, etc.), and insulating materials (cell-to-cell short-circuit prevention, mica, PI film, etc.) can be used.

[0097] FIG. 5 is a schematic diagram showing the wiring configuration of a sensor for a plurality of battery cells according to one embodiment of the present invention.

[0098] Each cell and sensor can be connected to a Battery Management System (BMS) via a multiplexer to form a battery pack. In the case of series or parallel connections, detection of normal and abnormal states can be performed through temporal comparison (storing the value during normal conditions in the BMS and comparing it with the value at the point of abnormal conditions). For example, when an abnormal pressure increase exceeding the normal pressure increase (or cell thickness increase) range is detected for each cell during charging, it can be individually detected that abnormal swelling has occurred in at least that cell.

[0099] FIG. 6 is a schematic diagram showing a battery abnormality detection scenario during charging according to one embodiment of the present invention.

[0100] According to one embodiment, abnormalities during battery charging can be detected by recording and comparing the sensor's measurement values ​​in the BMS.

[0101] Cell unit detection is a real-time continuous detection that detects volume expansion (degree of expansion, time to reach) during charging and can compare it with previous records. Figure 6 is a time-series comparison within a single cell. For a single cell that repeats charging and discharging according to time / distance, the cell thickness (volume expansion) or pressure can be measured to set a normal thickness range (normal volume range) after charging. If an abnormality occurs in a specific cell and the cell thickness or pressure value deviates from the normal thickness range, or if the critical thickness determined to be swelling is exceeded, the control unit (not shown) can provide a swelling notification signal to the user.

[0102] Battery pack unit detection is a real-time continuous detection that can simultaneously detect multiple cells and detect cells that exhibit outlier values ​​relative to the average value. It is also possible to continuously measure cell thickness or pressure for multiple cells as shown in FIG. 6. For example, for multiple cells that repeatedly charge and discharge according to time / driving distance, cell thickness (volume expansion) or pressure can be measured, and the average value can be set as the normal thickness range (normal volume range) after charging. If an abnormality occurs in a specific cell and it displays a cell thickness or pressure value outside the normal thickness range, or if it exceeds a critical thickness determined to be swelling, the control unit (not shown) can provide a swelling notification signal to the user.

[0103] FIG. 7 is a schematic diagram illustrating a battery abnormality detection scenario during driving or parking according to an embodiment of the present invention.

[0104] According to one embodiment, a method for detecting an abnormality while driving or parking is as follows.

[0105] Referring to FIG. 7, cell-unit detection is intermittent detection for reducing power consumption. When the difference between the values ​​measured by the sensor exceeds a certain level (first threshold), the control unit (not shown) can provide a first warning to the operator (user) to notify them. Of course, the detection method of FIG. 6 can be used in this process. After the first warning, the control unit can reduce the time interval for sensor detection and compare the detected value at the time of the first warning with subsequent values ​​to determine whether a second threshold has been reached, taking into account the difference and growth rate between the values. If the value measured by the sensor reaches the second threshold, the power supply to the corresponding cell or module can be cut off, and a second warning can be provided to the operator to notify them. Accordingly, there is an effect of preventing thermal runaway caused by continuous swelling after the first warning.

[0106] In addition, according to one embodiment, a method for detecting abnormalities during driving is as follows.

[0107] During driving, cell-level detection is possible. It can distinguish between situations requiring continuous real-time detection, such as vehicle impact or flooding, and situations requiring intermittent detection, such as normal driving.

[0108] Through vehicle-to-vehicle comparison, it is possible to compare data sets between vehicles with the same mileage or detect changes based on driving history within the same vehicle (detection of battery aging).

[0109] Multiple sensors are placed on the surface of the cell to detect the pressure distribution within a single cell. When pressure non-uniformity exceeding a certain level is detected, it is determined to be a precursor to swelling, and a warning can be issued in advance.

[0110] FIG. 8 is a diagram showing (a) a change in conductivity and (b) a change in repulsion force due to compression of a conductive elastic body according to one embodiment of the present invention.

[0111] As a process for manufacturing a conductive elastomer, the process for manufacturing a conductive foam using conductive particles according to one embodiment is as follows.

[0112] 1. A PVA-chitosan solution can be prepared.

[0113] For example, 10g of PVA (polyvinyl alcohol) and 100mL of distilled water can be mixed, and a PVA solution can be prepared by placing it on a hot plate at 95℃ and 1500rpm for 2 hours. Next, 1g of chitosan and 100mL of acetic acid (1%) can be mixed, and a chitosan solution can be prepared by placing it on a hot plate at 60℃ and 1500rpm for 2 hours. Next, the PVA solution and the chitosan solution can be mixed in a 7:3 ratio, and a PVA-chitosan solution can be prepared by placing it on a hot plate at 25℃ and 1500rpm for 1 hour.

[0114] 2. A PVA-chitosan solution and a conductive powder can be mixed in an 8:2 ratio. As the conductive powder, ground powders such as CF (carbon fiber), CNT, graphene, and MXene can be used.

[0115] 3-1. When manufacturing in the form of a conductive sponge, the sponge can be immersed in the mixed solution of 2 above, placed in a degasser, and vacuumed for 10 minutes to remove air bubbles from the surface of the sponge. Then, it can be placed in an oven and cured (solution evaporation) at 80°C for 2 hours.

[0116] 3-2. When making it into a conductive film, the PVA-chitosan solution and conductive powder can be mixed in a 9:1 ratio and then heat-cured under the same conditions as 3-1.

[0117] As a process for manufacturing a conductive elastomer, the process for manufacturing a conductive foam using a conductive polymer according to another embodiment is as follows.

[0118] 1. A PEG solution can be prepared. For example, 10g of PEG (polyethylene glycol, molecular weight = 3350) and 90mL of distilled water can be mixed.

[0119] 2. Conductive solutions can be diluted. To finely tune the conductivity of the conductive elastomer, a pure conductive solution such as PEDOT:PSS can be used diluted to a low concentration. PEDOT:PSS (1.3 wt%) can be diluted to 0.5 to 1.0 wt%. Dilution can be performed because using 1.3 wt% PEDOT:PSS as is results in very high conductivity of the conductive elastomer, which may cause a short circuit. When diluting, solvents such as ethanol, isopropanol, or methanol may be added. Conductive solutions such as polyacetylene (PA) or polyaniline (PANI) can be used instead of PEDOT:PSS.

[0120] 3. The PEG solution and the diluted conductive solution can be mixed. The PEG and the conductive solution can be mixed in a volume ratio of 3:1 and stirred for 2 hours.

[0121] 4. Sponges can be plasma treated. Polyurethane sponge under plasma conditions of 20W, basic vacuum 2 x 10 -2 Plasma treatment can be performed under conditions of Torr, process vacuum 0.5 Torr, frequency 50 kHz, time 5 min, and O2 gas flow rate 15 sccm.

[0122] 5. After immersing the plasma-treated sponge in the mixed solution of step 3, it can be placed in a degasser to remove air bubbles from the surface of the sponge under vacuum. Subsequently, it can be placed in an oven and cured (solution evaporation) at 60 to 80°C for 2 hours. If necessary, the process of step 5 can be repeated to reduce the resistance of the conductive foam.

[0123] 6. A post-treatment process can be performed. It can be immersed in a 1-2% HCl solution for 3 minutes and then washed with DI water. Subsequently, it can be placed in an oven and cured (solution evaporation) at 120-150°C for 30 minutes.

[0124] Referring to Fig. 8, after fabricating a conductive foam using the aforementioned conductive particles, changes in conductivity and repulsion force were measured upon compression. As shown in Fig. 8 (a), it can be seen that the resistance decreases as compression increases. Additionally, as shown in Fig. 8 (b), it can be seen that the repulsion force increases as compression increases. The repulsion force can correspond to the compressive force applied to the elastic body while it is being compressed, that is, while the thickness of the elastic body is decreasing.

[0125] FIG. 9 is a schematic diagram showing a sensor (100: 100-1) according to a first embodiment of the present invention. The following embodiments show a piezoresistive foam pressure sensor.

[0126] Referring to FIG. 9, a sensor (100: 100-1) for detecting swelling of a battery may include a conductive part (110), a non-conductive part (120), and a resistance measuring electrode (130). Additionally, a control unit (not shown) connected to the resistance measuring electrode (130) to process signals may be further included. The control unit (not shown) may also be connected to a BMS to transmit, receive, and process signals related to control.

[0127] The conductive part (110) may use a conductive elastic body (conductive foam / conductive sponge) as described above in FIG. 8. The non-conductive part (120) may use a non-conductive elastic body (non-conductive foam / non-conductive sponge) distinct from the conductive part (110) so as to have non-conductive characteristics. A pair of resistance measuring electrodes (130) may be connected to the conductive part (110). Since the resistance may change when the elastic body is compressed by external pressure, the degree to which the elastic body of the conductive part (110) is compressed can be calculated based on the resistance measured through the resistance measuring electrodes (130).

[0128] For example, the sensor (100) may be placed between cells, on the side wall of a cell / case, etc., as described above in FIG. 3. Since the conductive part (110) is compressed when swelling occurs in a characteristic cell, a control unit (not shown) measures the change in resistance and calculates the degree to which the elastic body of the conductive part (110) is compressed, and can give an alarm to the user if it exceeds a preset threshold. The embodiments described above in FIG. 5 to 7 may be applied without limitation.

[0129] FIG. 10 is a schematic diagram showing a sensor according to a second embodiment of the present invention. FIG. 11 is a schematic diagram showing a sensor according to a third embodiment of the present invention. FIG. 12 is a schematic diagram showing parallel connection wiring configured by applying the sensors of FIG. 10 to FIG. 11.

[0130] The sensor (100: 100-2, 100-3) of FIGS. 10 and 11 may include a conductive part (110), a non-conductive part (120), a resistance measuring electrode (130), and a capacitance measuring electrode (140: 141, 142). The sensor (100-2, 100-3) may represent an RC sensor and may apply the RC measurement principle of FIG. 2 (a). A pair of capacitance measuring electrodes (141, 142) may be connected to one side of the conductive part (110) and the other side facing it. For example, in FIG. 11, the electrode (130) may be applied as a Vin electrode, the electrode (141) as a Vc electrode, and the electrode (142) as a ground electrode.

[0131] The sensor (100-2, 100-3) can simultaneously measure piezoresistance and capacitance when the conductive part (110) is compressed. In addition, it can measure changes in resistance and capacitance due to thickness compression. Furthermore, it has the advantage of simplifying RC measurement and wiring.

[0132] The input voltage is V in = 0 (t < 0 sec), V in If given as = V (t ≥ 0 sec),

[0133] The voltage across the capacitor C is V c (t) = V (1 - e (-t / RC) ) am.

[0134] For example, assuming a pouch-type cell area of ​​300 cm² and a compression pad thickness of approximately 5 mm, the sponge capacitance is calculated as C(t) = (2.65 X 10⁻⁶ -10 XF) / t. (The unit of compression thickness t is mm)

[0135] Meanwhile, the change in conductivity in Fig. 8 can be expressed as an equation: R(t) = 9.56 X 10 5 X t -2.684 am.

[0136] When examining the change in the time constant (R(t) * C(t)) according to the compression thickness t, the time constant decreases exponentially. Therefore, it can be confirmed that the measurement of the time constant of a parallel-connected RC circuit is much more sensitive to compression (or swelling) than that of a parallel-connected resistor, and that the presence or absence of a swelling cell within a single module (or pack) containing multiple cells can be detected using only four wires (two wires for power supply and two wires for measurement).

[0137] Referring to FIG. 12, if the Vin of the conductive part (110) of each sensor (100-2, 100-3) is connected in parallel and the VC of the conductive part (110) is connected in parallel, only four wires (two for power and two for measurement) are required per module. Since the time constant increases only in the swollen cell, it exhibits a steep graph slope as shown in FIG. 12, and there is an advantage in being able to detect whether there is an abnormality in the cell. A control unit (not shown) connected to the electrode can determine that there is an abnormality in the cell if a time constant different from that of the remaining cells is measured in the specific swollen cell.

[0138] FIG. 13 is a schematic diagram showing a coil portion used in a sensor according to one embodiment of the present invention. (a) is a side schematic diagram, and (b) is a plan schematic diagram. The coil (50) is a film-type coil and can be used in the sensor (100: 100-4, 100-5) of FIG. 14 and FIG. 15.

[0139] The coil portion (50) may include a spiral coil (150) formed on an insulating flexible film (160). An upper surface electrode (151) and a lower surface electrode (152) may be extended at both ends of the spiral coil (150).

[0140] For example, if a resistance measuring electrode (130) is added, the RL measurement principle of FIG. 2 (b) can be applied, and at this time, the voltage across L is V L (t) = VX e -tR / L This is. When a capacitance measuring electrode (140) is added, the LC measurement principle of FIG. 2 (c) can be applied.

[0141] FIG. 14 is a schematic diagram showing a sensor according to a fourth embodiment of the present invention. FIG. 15 is a schematic diagram showing a sensor according to a fifth embodiment of the present invention. FIG. 16 is a schematic diagram showing a sensor according to a sixth embodiment of the present invention. FIG. 17 is a schematic diagram showing a measurement circuit of the pressure / distance sensor of FIG. 14 to FIG. 16.

[0142] The sensors (100: 100-4, 100-5, 100-6) of FIGS. 14 to 16 represent pressure / distance sensors according to various embodiments. In each figure, (a) represents a normal state, and (b) represents a state where swelling has occurred.

[0143] Referring to FIG. 14, the sensor (100: 100-4) may include a coil portion (50), an elastic body (70), and a metal film portion (170). When swelling occurs in the cell (C') as in FIG. 14 (b), the metal film portion (170') and the elastic body (70') may be compressed by the cell (C'), causing deformation. Accordingly, the degree to which the elastic body (70) is compressed can be calculated by measuring the voltage changed in the coil portion (50).

[0144] Referring to FIG. 15, the sensor (100: 100-5) may include a coil portion (50), an elastic body (70), and a magnetic elastic body (180).

[0145] The magnetic elastomer (180) may include an elastic material in which magnetic particles are dispersed in a matrix. For example, the magnetic elastomer (180) may include at least a magneto-rheological elastomer (MRE) and may itself be composed of a magneto-rheological elastomer. For example, the magnetic particles may be selected from at least one of iron, carbonyl iron, iron alloy, iron oxide, iron nitride, iron carbide, low-carbon steel, nickel, cobalt, and mixtures thereof or alloys thereof. Additionally, the magnetic particles may be uncoated magnetic particles or magnetic particles coated with an organic resin. Additionally, the magnetic particles may include neodymium (Nd)-based materials such as FeNdB. The matrix material may be any one of polymers such as natural rubber or synthetic rubber.

[0146] As shown in FIG. 15 (b), when swelling occurs in the cell (C'), the magnetic elastic body (180') and the elastic body (70') may be compressed by the cell (C'), causing deformation. The deformed magnetic elastic body (180') can apply a magnetic field of a different strength to the coil portion (50) compared to the magnetic elastic body (180) before deformation. Accordingly, the degree to which the elastic body (70) is compressed can be calculated by measuring the changed magnetic field in the coil portion (50).

[0147] Referring to FIG. 16, the sensor (100: 100-6) may include a coil portion (50) and a magnetic elastomer (180). In a rectangular / cylindrical cell case containing a jelly roll (R) inside, if swelling occurs in the jelly roll (R'), the magnetic elastomer (180') may be compressed by the jelly roll (R') and deformation may occur. The deformed magnetic elastomer (180') may apply a magnetic field (M -> M') of a different strength to the coil portion (50) compared to the magnetic elastomer (180) before deformation. Accordingly, the degree to which the magnetic elastomer (180) is compressed can be calculated by measuring the changed magnetic field (M -> M') in the coil portion (50).

[0148] Referring to FIG. 17, a measurement circuit of a pressure / distance sensor as shown in FIG. 14 to FIG. 16 can be configured. The measurement circuit can be configured as an RLC or a mixed RC / LC / RL type.

[0149] FIGS. 18 and 19 are schematic diagrams showing sensor arrangement forms according to various embodiments.

[0150] FIG. 18 illustrates a foam-type sensor. For example, (a) and (b) are pouch-type LiPo batteries, in which the sensor (100) can be placed on the surface of the pouch [or cell (C)]. (c) and (d) are prismatic-type or cylindrical-type batteries, in which the sensor (100) can be placed on the inner side wall of the case (MC).

[0151] (a) shows a form in which the sensor (100) is placed on the surface of a pouch, the surface of a cell (C), or between cells (C) with an insulating material (IS) interposed, and (c) shows a form in which the sensor (100) is placed on the inner side wall of a jelly roll (R) and a case (MC) with an insulating material (IS) interposed. (a) and (c) can detect swelling by measuring the RC time.

[0152] (b) shows a configuration in which a magnetic foam and magnetic field sensor (100) as shown in FIGS. 15 to 16 is placed on the surface of a pouch, the surface of a cell (C), or between cells (C) with a Hall sensor (HS) interposed therebetween; (d) shows a configuration in which a magnetic foam and magnetic field sensor (100) is placed on the inner wall of a case (MC) and a Hall sensor (HS) is placed on the outer wall of a case (MC). The Hall sensor (HS) can measure the Hall voltage due to the Hall effect described above.

[0153] FIG. 19 illustrates a film-type sensor. For example, (a) and (b) are pouch-type LiPo batteries, in which the sensor (100) can be placed on the surface of the pouch [or cell (C)]. (c) and (d) are prismatic-type or cylinder-type batteries, in which the sensor (100) can be placed on the inner side wall of the case (MC).

[0154] (a) shows a form in which a film-type sensor (100) is placed between a cell (C) and a foam (FM), and (c) shows a form in which a film-type sensor (100) is placed between a jelly roll (R) and a case (MC). (a) and (c) can detect swelling by measuring the RC time.

[0155] (b) shows a configuration in which a magnetic film (MF) and a magnetic field sensor (100), such as those in FIGS. 15 and 16, are placed on the surface of a pouch, on the surface of a cell (C), or between cells (C), as well as a Hall sensor (HS). (d) shows a configuration in which a magnetic film (MF) and a magnetic field sensor (100) are placed inside a case (MC), and a Hall sensor (HS) is placed on the outer wall of the case (MC). The Hall sensor (HS) can measure the Hall voltage caused by the Hall effect described above. In particular, the magnetic film configurations of (c) and (d) are expected to show a greater change in the magnetic field compared to the magnetic foam of FIG. 18 (c) and (d).

[0156] FIG. 20 is a photograph showing a sensor with a conductive elastic applied according to one embodiment of the present invention.

[0157] FIG. 20 shows a sensor (100) comprising a conductive sponge as a conductive part (110), which is prepared by mixing a conductive powder into the PVA-chitosan solution described above in FIG. 8 and then immersing a sponge (or compression pad). The sensor may be equipped with a resistance measuring electrode (130) that measures pressure applied to the conductive sponge, such as the sensor (100: 100-1) in FIG. 9. The conductive powder may be carbon fiber (CF), CNT, graphene, MXene, etc.

[0158] FIGS. 21 to 23 are schematic diagrams showing the characteristics of sensors according to conductive materials of conductive elastomers according to various embodiments of the present invention.

[0159] FIG. 21 shows the compression-force dynamic (CFD) characteristics of a sensor using CF and CNT as conductive powders. The concentration of CF and CNT corresponds to the mass of the conductive powder relative to the mass of the PVA-chitosan solution. Distance corresponds to the depth to which the conductive part (110) is pressed. It can be seen that the resistance value is lower when CF is used than when CNT is used, but the deviation is large. Also, when the same material is used, it can be seen that the resistance value decreases as the concentration increases.

[0160] FIG. 22 shows the compression-force dynamic (CFD) characteristics of a sensor using MXene as a conductive powder. The concentration of MXene corresponds to the mass of the conductive powder relative to the mass of the PVA-chitosan solution. H corresponds to the depth of pressing the conductive part (110). For example, Ti3C2 was used as the MXene, but M n+1 X n T x (M is a transition metal, X is carbon or nitrogen, T xMXenes of other components that are functional groups can also be used without restriction. It can be observed that the resistance value decreases as the concentration of MXene increases.

[0161] Figure 23 shows the compression-force dynamic (CFD) characteristics of a sensor using graphene as a conductive powder. The compression depth was set to 0–3 mm, and the cycle of compression (3 mm) → recovery (0 mm) → compression (3 mm) → recovery (0 mm) was repeated. When the graphene content is 0.2% to 5.0%, the trend of the resistance change value for compression / recovery is not clearly visible. When the content is 10.0%, the resistance value decreases during compression and increases during recovery, and it can be confirmed that the trend of the resistance change value for compression / recovery is clear. The trend of the resistance change value for compression / recovery is clearly visible up to 10.0% to 20.0% of graphene, and if too much graphene is included, the change in the resistance value for compression / recovery may not be clearly visible and may appear at a constant level.

[0162] FIGS. 24 and 25 are schematic diagrams showing the charge-discharge characteristics of a conductive elastomer according to various embodiments of the present invention. FIG. 24 shows the charge-discharge characteristics when CNT is 1%, and FIG. 25 shows the charge-discharge characteristics when graphene is 10%.

[0163] Referring to Fig. 24, it can be seen that sample cell A was charged for approximately 25 minutes and then discharged. Changes in the battery volume during charging and discharging can be detected through pressure values. During charging, a decrease in resistance, an increase in cell voltage, and an increase in pressure are observed, while during discharging, an increase in resistance, a decrease in cell voltage, and a decrease in pressure are observed. It can be observed that when the pressure increases during charging, the distance between the conductive particles of the elastic material becomes closer, causing the resistance to decrease.

[0164] Referring to Fig. 25, it can be seen that five charge-discharge cycles were performed on sample cell A. During charging, a decrease in resistance, an increase in cell voltage, and an increase in pressure are observed, while during discharging, an increase in resistance, a decrease in cell voltage, and a decrease in pressure are observed. It can be seen that the pressure of the cell did not exceed the critical range even during repeated charge-discharge processes.

[0165] FIG. 26 is a schematic diagram showing the process of detecting battery swelling during charging and discharging according to one embodiment of the present invention.

[0166] Referring to Figures 26 (a) and (b), it can be seen that charging and discharging were repeated five times. During charging, a decrease in resistance, an increase in cell voltage, and an increase in pressure are observed, while during discharging, an increase in resistance, a decrease in cell voltage, and a decrease in pressure are observed.

[0167] Referring to Figures 26 (b) and (c), it can be observed that resistance and pressure increase rapidly after approximately 320 min during the process of repeated charging and discharging. The control unit can determine that the battery swelling stage has occurred if the resistance and pressure exceed the normal range, particularly if they exceed a preset threshold range. If the resistance and pressure do not return to the normal range and are measured to be outside the threshold range or to a higher value thereafter, the control unit can cut off the power supply to the cell or module. Accordingly, this has the effect of preventing thermal runaway caused by continuous swelling.

[0168] FIG. 27 is a schematic diagram showing a sensor according to an additional embodiment of the present invention.

[0169] In addition to detecting the normal volume change (pressure) caused by charging and discharging as described in FIGS. 24 to 26, a separate detection capability may be required when swelling becomes severe. Accordingly, an improved structure is proposed for detecting swelling.

[0170] Referring to FIG. 27 (a) and (b), the sensor (100: 100-7) may include a conductive part (110) and an electrode (EL). Optionally, a non-conductive part (120) [see FIG. 9] may be included around the conductive part (110).

[0171] Holes (TH) may be formed in the conductive portion (110) of the conductive elastic body. In FIG. 26 (b), holes (TH) of various sizes are formed as an example. Additionally, electrodes (EL) may be formed on one side (upper surface) of the conductive portion (110) and on the other side (lower surface) facing it.

[0172] When the cell contacted by the sensor (100) swells, pressure (P) [external force on the sensor] may be applied to the electrode (EL) of the sensor (100). When the pressure (P) reaches a threshold value, the upper electrode (EL) and the lower electrode (EL) are pressed together and move closer to each other. Here, the threshold value corresponds to the pressure value at which the battery cell enters the swelling stage beyond the normal usage range. In particular, if the upper electrode (EL) and the lower electrode (EL) come into contact on the hole (TH), a short circuit may occur due to direct contact. The control unit (not shown) detects that the resistance decreases rapidly [or decreases discontinuously / intermittently] due to the short circuit and determines that it is an abnormal state (swelling stage) rather than a normal state.

[0173] FIGS. 28 to 29 are schematic diagrams showing short-circuit generation characteristics according to the hole size of the sensor of FIG. 27.

[0174] FIG. 28 is the result of measuring the resistance value relative to pressure by forming holes (TH) with (width x height) of (4.0cm x 4.0cm) to (5.0cm x 5.0cm) in a conductive part (110) [conductive elastic body] with a thickness of 3mm. When the size of the holes (TH) is 4.8cm x 4.8cm or larger, a part where the resistance value decreases rapidly [or decreases discontinuously / intermittently] appears, and this part can be considered as the part where a short circuit occurred. It can be confirmed that the larger the size of the holes (TH), the more a short circuit occurs under less pressure.

[0175] FIG. 29 is a graph showing the pressure at which a short circuit occurs for each hole (TH) size according to the data in FIG. 28. The pressure range during charging and discharging of the battery may correspond to approximately 160 to 170 kgf. The normal range of the battery includes the pressure range during charging and discharging and a pressure range lower than this. Cases where a short circuit occurs at a pressure value greater than this may correspond to an appropriate hole (TH) size for detecting the short circuit (detecting swelling).

[0176] When the hole size is 4.8cm X 4.8cm, a short circuit may occur at a pressure value of approximately 207kgf. Therefore, a hole size of 4.8cm X 4.8cm is usable.

[0177] When the hole size is 4.9cm x 4.9cm, a short circuit occurs at a pressure value of approximately 90kgf. Since a short circuit occurs at a pressure value of approximately 90kgf, it implies that a short circuit occurs during charging or discharging, or even during normal battery usage, so it is not considered an appropriate hole size for use. The same applies when the hole size is larger than 4.9cm x 4.9cm.

[0178] Considering Fig. 29, since short circuits do not easily occur when the hole size is 4.75 cm X 4.75 cm, for a conductive elastomer with a thickness of 3 mm, a hole size greater than 4.75 cm X 4.75 cm and less than or equal to 4.8 cm X 4.8 cm can be appropriately considered. In other words, the hole size can be greater than 15.83 times and 16 times the thickness of the conductive elastomer.

[0179] Not limited to the above embodiments, the hole size may vary depending on the thickness and hardness (or Young's Modulus) of the elastomer and the range of pressure (or force) to be measured. That is, the thinner the thickness of the elastomer, the smaller the hole size required for short-circuiting may be, and the lower the hardness, the smaller the hole size required for short-circuiting may be. In addition, if a large force is to be sensed at the same thickness and hardness of the elastomer, an adjustment to reduce the hole size may be performed.

[0180] As described above, the present invention can detect an abnormal condition of swelling before thermal runaway of a battery, and has the effect of preventing fire accidents caused by the battery and enabling preemptive measures.

[0181] FIGS. 30 to 31 are schematic diagrams showing various embodiments of the sensor of the present invention.

[0182] Referring to FIG. 30, meanwhile, the sensor of the present invention can be usefully utilized in the field of robots and robotics. In particular, a force / pressure sensing technology utilizing the piezoresistive properties of a conductive elastomer can be applied. The sensor (100) can be applied to the outer shell of a robot (300) or to the end of a finger (310). When the finger (310) of the robot (300) comes into contact with an external object, the conductive elastomer part of the sensor (100) is compressed by the object, and the deformed pressure / distance can be detected. In addition, as a plurality of sensors (100) are applied to multiple areas of the outer shell of the robot (300), the intensity and distribution of the force acting upon contact with an external object can be precisely detected.

[0183] Through this, the robot (300) can perceive the location and magnitude of the force generated upon contact with a person or object in real time, which has the effect of being applicable to various fields such as the tactile system of a humanoid robot requiring delicate operation, the control system of a prosthetic arm / leg, and the user feedback system of a rehabilitation robot. In particular, since the elastic or foam-based pressure sensing sensor has flexible characteristics and low-power operation characteristics, it can provide excellent advantages in terms of human body mimicry and energy efficiency compared to conventional rigid sensors.

[0184] In addition to this, the sensor (100) of the present invention can be utilized as a general-purpose force sensor.

[0185] Referring to FIG. 31, the sensor (100) may be applied to the surface of the home appliance (400). The sensor (100) may be applied to an input device, such as an operation button of the home appliance (400). Alternatively, the sensor (100) may be applied to the display (410) of the home appliance (400) or to the display device itself. The sensor (100) may be applied within the display (410) and used as a touch sensor to detect the force applied by a user to the display. As a plurality of sensors (100) are applied to multiple areas of the home appliance (400) or the display (410), the intensity and distribution of the force acting upon contact with an external object may be precisely detected.

[0186] Although the present invention has been illustrated and described with reference to preferred embodiments as described above, it is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art within the scope of the invention without departing from the spirit of the invention. Such modifications and changes should be deemed to fall within the scope of the present invention and the appended claims.

Claims

1. A system for detecting abnormalities in a battery using a sensor that detects battery swelling, The above sensor is, A conductive elastomer deformable by external force; and Electrode connected to the above conductive elastic body; Includes, A battery abnormality detection system that measures a change in at least one of R (resistance), L (inductance), and C (capacitance) of the conductive elastic body transmitted through the electrode when the conductive elastic body is deformed by an external force.

2. In Paragraph 1, The above sensor is positioned on the side or inside of a battery cell, or on the side or inside of a case of a battery pack including a plurality of batteries, and A battery abnormality detection system that applies an external force to a conductive elastic body to cause deformation when the battery cell or battery pack swells.

3. In Paragraph 2, A battery abnormality detection system further comprising: a control unit connected to the electrodes and receiving signals for R, L, and C.

4. In Paragraph 1, The above conductive elastomer includes a conductive part having conductivity and a non-conductive part having non-conductivity, and A battery abnormality detection system, wherein the electrode comprises at least a resistance measuring electrode, and the resistance measuring electrode is connected to a conductive part.

5. In Paragraph 4, A battery abnormality detection system, wherein the above electrode further includes a capacitance measuring electrode, and the capacitance measuring electrode is connected to the non-conductive part.

6. In Paragraph 3, The above-mentioned sensor includes a plurality of units, and the battery includes a plurality of battery cells. A battery abnormality detection system that determines that swelling has occurred in a cell when an abnormal pressure increase outside the normal pressure increase range is detected during the charging of each of the above-mentioned battery cells.

7. In Paragraph 3, The above-mentioned sensor includes a plurality of units, and the battery includes a plurality of battery cells. Each of the above sensors is placed in each of the above battery cells, and the V of the sensor in and V c is connected in parallel with the above battery cell, and The above control unit is a battery abnormality detection system that determines that a specific cell is abnormal if a time constant different from that of the remaining cells is measured in a specific swollen cell.

8. In Paragraph 3, The control unit measures the degree of volume expansion during charging as a specific battery cell repeats charging and discharging cycles using the external force applied to the conductive elastic body, and sets a normal volume range after charging. A battery abnormality detection system that determines swelling of a specific battery cell when a value outside the normal volume range is measured in the specific battery cell.

9. In Paragraph 3, The above-mentioned sensor includes a plurality of units, and the battery includes a plurality of battery cells. The control unit measures the average value of the degree of volume expansion during charging as the external force applied to the conductive elastic body during the process in which the plurality of battery cells repeatedly charge and discharge, and sets a normal volume range after charging. A battery abnormality detection system that determines swelling of a specific battery cell when a value outside the normal volume range is measured in a specific battery cell.

10. In Paragraph 8 or 9, A battery abnormality detection system in which the control unit compares a measurement value at a first point in time in the specific battery cell with a measurement value at a second point in time after the first point in time, and cuts off the power supply to the battery if the measurement value increases.

11. In Paragraph 1, The above conductive elastomer comprises a foam, sponge, pad, or film, in a battery abnormality detection system 12. In Paragraph 1, The above sensor further includes a magnetic elastic body, and A battery abnormality detection system that applies a magnetic field of a different strength to the conductive elastic body when the magnetic elastic body is deformed by an external force.

13. In Paragraph 1, The above conductive elastomer is, A foam comprising any one of a sponge, a compression pad, a film, or a polymer; and A conductive material comprising at least one of carbon fiber, graphene, MXene, graphite, carbon black, and a conductive polymer; A battery abnormality detection system including 14. In Paragraph 4, A battery abnormality detection system having a hole formed penetrating one side of the conductive part and the other side opposite to the one side, and at least a portion of the electrode disposed on the one side and the other side of the hole.

15. In Paragraph 14, If the external force applied to the conductive part exceeds a critical value, the electrode on one surface and the electrode on the other surface come into contact within the hole, causing a short circuit. A battery abnormality detection system in which the above control unit detects a discontinuous decrease in resistance caused by the short circuit and determines swelling of the battery.

16. A method for detecting whether there is an abnormality in a battery using a sensor that detects battery swelling, (a) a step of providing a sensor comprising: a conductive elastomer deformable by an external force; and an electrode connected to the conductive elastomer; (b) a step of placing the sensor on the side or inside of a battery cell, or on the side or inside of a case of a battery pack including a plurality of batteries; (c) a step of measuring a change in at least one of R (resistance), L (inductance), and C (capacitance) of the conductive elastic body transmitted through the electrode when the conductive elastic body is deformed by an external force; A method for detecting abnormalities in a battery, including

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