Lithium battery short circuit detection device and detection method

Abstract

The invention relates to the technical field of lithium battery detection, and discloses a lithium battery short circuit detection device and a detection method.The lithium battery short circuit detection device comprises a base and a water pool installed in the base, a liftable platform is arranged in the water pool, the water pool is filled with insulating oil, and when the temperature of a lithium battery on the platform is abnormal, and the lithium battery drops and is led into the insulating oil, the lithium battery is started; spontaneous combustion is prevented; the base is provided with a detection circuit used for connecting the positive electrode and the negative electrode of the lithium battery. Non-contact detection is carried out through rotating magnetic field excitation, a battery shell does not need to be disassembled, and physical damage to the battery is avoided; the mechanical impact is controllably applied through the impact bomb, the impact strength and angle can be accurately adjusted, only the collision stress of the actual working condition is simulated, the battery structure is not excessively damaged, the qualified battery can still be subsequently used after detection, the battery loss in the detection process is reduced, and the production cost of an enterprise is reduced.

Description

Technical Field

[0001] This invention relates to the field of lithium battery testing technology, specifically to a lithium battery short-circuit testing device and testing method. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density, long cycle life, and low environmental pollution, have been widely used in new energy vehicles, consumer electronics, and energy storage devices. However, during production, transportation, and use, lithium-ion batteries are susceptible to hidden damage such as internal electrode misalignment, separator damage, and conductor structure fracture due to mechanical stress from collisions and compression. This damage is difficult to identify initially through visual inspection or simple electrical testing, but it can trigger internal short circuits during subsequent charging and discharging, leading to a rapid increase in battery temperature, thermal runaway, or even spontaneous combustion and explosion, seriously threatening personal and property safety. Therefore, accurate and comprehensive testing of lithium-ion batteries (especially those subjected to mechanical impact) to detect internal damage and short-circuit risks has become a crucial step in ensuring the reliability and safety of lithium-ion battery products.

[0003] Traditional testing technologies primarily focus on monitoring the electrical parameters (such as voltage and internal resistance) of finished batteries. They can only identify batteries with obvious short circuits and cannot detect hidden internal damage caused by impacts, such as micro-cracks in the electrodes or localized damage to the separator. These hidden damages initially show no abnormal electrical parameters, but easily develop into short circuits during subsequent use, leading to a disconnect between the test results and the actual safety status. Some technologies attempt to use single physical detection methods, but X-ray equipment is expensive and complex to operate, and ultrasonic testing has limited resolution for the internal conductor structure of the battery, making it difficult to accurately locate minute damage. Therefore, this invention provides a lithium battery short-circuit detection device and method. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides a lithium battery short-circuit detection device and detection method.

[0005] The present invention provides the following technical solution: a lithium battery short circuit detection device, including a base and a water tank installed inside the base. The water tank is provided with a liftable platform and is filled with insulating oil. When the lithium battery on the platform has an abnormal temperature, it is lowered and introduced into the insulating oil to prevent it from spontaneously combusting. The base is equipped with detection lines for connecting the positive and negative terminals of the lithium battery. The detection lines are connected to the positive and negative terminals of the lithium battery to monitor the status of the lithium battery in real time. A shielding chamber is installed on the base, and the front cover of the shielding chamber is a flip-top design to allow the lithium battery to be introduced and exported. The shielded cabin is equipped with an electromagnetic catapult, and the position and angle of the electromagnetic catapult are adjusted by a drive structure so that the electromagnetic catapult launches an impact projectile to collide with the lithium battery. The state of the lithium battery after the impact is detected by a detection circuit. The shielding chamber is equipped with a magnetic field structure inside. By generating a rotating magnetic field, it can penetrate the outer shell of the lithium battery and induce eddy currents in the conductor structure inside. When there is damage inside the battery, the distribution of eddy currents in the damaged area is distorted, resulting in an abnormal local temperature rise in that area. The shielded chamber is equipped with several sets of infrared sensors to detect the temperature of the lithium battery in real time after the impact.

[0006] Preferably, the bottom of the platform is raised and lowered by a hydraulic device, and the surface of the platform is provided with holes for insulating oil to pass through, so that after the platform is immersed in the water pool, the insulating oil can penetrate the lithium battery through the holes on the platform surface.

[0007] Preferably, the drive structure includes a frame installed at the top of the inner side of the shielded cabin. A-type modules and B-type modules are symmetrically distributed vertically on the frame. Connecting frames are installed on the Y-axis module sliders of both A-type and B-type modules. Spherical sleeves are installed on the connecting frames, and the interior of the spherical sleeves contains rollable guide balls. The guide balls have holes for mounting the electromagnetic catapult. The electromagnetic catapult is fixed to the top of the electromagnetic catapult via the holes on the two guide balls. The bottom of the electromagnetic catapult is slidably connected to the hole in the lower guide ball. The overall position of the electromagnetic catapult is adjusted by the A-type and B-type modules, while the angle of the electromagnetic catapult is adjusted by the B-type module.

[0008] Preferably, the magnetic field structure includes support plates installed on the front, rear, left, and right sides of the inner wall of the shielded cabin. The support plates have annular grooves, and excitation coils are embedded in the annular grooves of the support plates. The excitation coils at the front and rear positions and the left and right positions are divided into two groups. Two sinusoidal alternating currents with equal amplitude, the same frequency, and a phase difference of degrees are simultaneously passed to the two groups of excitation coils. A uniform rotating magnetic field is synthesized in the shielded cabin, in which the magnetic field lines rotate at a constant speed in a plane perpendicular to the axes of the two coils.

[0009] Preferably, the two sets of excitation coils are arranged opposite each other on opposite sides of the shielded cabin, so that the axes of the two sets of excitation coils are orthogonal to form a rotating magnetic field.

[0010] Preferably, a protective plate is laid on the outer side of the support plate, which is made of a non-magnetic, non-conductive, high-resistivity rigid material, so that the magnetic field can penetrate without significant attenuation or distortion.

[0011] A short-circuit detection method for lithium batteries, the specific operation of which is as follows: S1: Lift the platform to the detection position using the lifting and bearing mechanism, place the lithium battery on the platform, and connect the detection line; S2: Control the electromagnetic catapult to adjust to the preset position and angle to apply mechanical impact to the lithium battery; S3: After the impact, a rotating magnetic field is generated by the magnetic field structure to excite the lithium battery. At the same time, an infrared sensor is used to collect the time-series temperature field image of its surface, detect temperature changes, and identify and locate the internal damage location. S4: If the temperature or electrical parameters are detected to be abnormally high and exceed the safety threshold, the platform will be lowered immediately to immerse the lithium battery in insulating oil.

[0012] Compared with the prior art, the present invention has the following beneficial effects: (1) The device adopts a dual excitation mode of mechanical impact and rotating magnetic field. Mechanical impact can simulate the collision conditions of lithium battery during transportation and use. Rotating magnetic field can penetrate the battery shell without contact and induce eddy currents in the internal conductor. If there is internal damage, the eddy current distortion will cause local abnormal temperature rise. With the synchronous acquisition of dual parameters of infrared temperature monitoring and electrical parameter monitoring, the temperature field image can accurately locate the damage location, and the electrical parameters directly reflect the short circuit risk. The dual data corroborate each other, avoiding misjudgment of a single detection dimension. The detection results are more in line with the actual use scenario, and the accuracy is far greater than that of traditional single detection methods.

[0013] (2) The drive structure can flexibly adjust the position and launch angle of the electromagnetic catapult, and can be adapted to lithium batteries of different specifications and different detection points without replacing the core components; the rotating magnetic field is synthesized by orthogonal excitation coils, which can be adapted to lithium battery shells of different sizes, without the need to specifically adjust the magnetic field parameters. The equipment has strong versatility and adaptability, and can meet diverse short circuit detection needs, reducing the equipment investment cost for multi-specification product detection.

[0014] (3) When the temperature or electrical parameters are detected to be abnormally high, the platform can quickly descend and immerse the lithium battery in insulating oil, instantly isolating it from the air and preventing the lithium battery from spontaneously combusting. The response is rapid and without delay. At the same time, the shielding chamber can effectively shield external electromagnetic interference and prevent the internal magnetic field and impact energy from radiating outward. This ensures the accuracy of the detection and prevents the safety risks caused by electromagnetic pollution and mechanical impact, thus comprehensively improving the safety of the detection process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 Internal structure diagram; Figure 3 This is a schematic diagram of the driving structure of the present invention; Figure 4 For the present invention Figure 3 A partial structural diagram; Figure 5This is a schematic diagram of the overall magnetic field structure of the present invention; Figure 6 This is a schematic diagram of the protective plate installation structure of the present invention; Figure 7 This is a schematic diagram showing the installation positions of the four excitation coils in this invention.

[0016] In the diagram: 1. Base; 2. Water tank; 3. Platform; 4. Detection circuit; 5. Shielded cabin; 6. Magnetic field structure; 7. Electromagnetic catapult; 8. Drive structure; 81. Frame; 82. Type A module; 83. Type B module; 84. Connecting frame; 85. Spherical sleeve; 86. Guide ball; 61. Support plate; 62. Excitation coil; 63. Protective plate. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. In order to keep the following description of the embodiments of this disclosure clear and concise, detailed descriptions of known functions and known components are omitted to avoid unnecessarily obscuring the concept of the present invention.

[0018] Please see Figure 1 and Figure 2 The device uses base 1 as the overall support foundation. All core functional components are integrated on base 1 and its supporting structure according to the detection logic, forming a closed-loop detection system. Base 1 has a water tank 2 inside, which is filled with insulating oil. Inside the water tank is a liftable platform 3, which serves as a support platform for the lithium battery, and has the dual functions of supporting the detection station and providing emergency protection for descent. Detection lines 4 are laid on base 1 to connect to the positive and negative terminals of the lithium battery, so as to realize real-time monitoring of electrical parameters.

[0019] A shielding chamber 5 is fixedly installed on the base 1. Its front cover adopts a flip-top design, which facilitates the loading and unloading of lithium batteries. At the same time, the shielding chamber 5 can effectively shield external electromagnetic interference to avoid affecting the accuracy of internal magnetic field detection, and also prevent the influence of internal rotating magnetic field and mechanical impact from spreading outward.

[0020] The core detection area is located inside the shielded chamber 5, which integrates a magnetic field structure 6, an electromagnetic catapult 7, a drive structure 8, and several sets of infrared sensors. The magnetic field structure 6 is installed on the inner wall of the shielded chamber 5 to generate a rotating magnetic field to excite eddy currents inside the lithium battery. The electromagnetic catapult 7 is suspended inside the shielded chamber 5 through the drive structure 8, and its position and angle can be freely adjusted to complete the mechanical impact on the lithium battery. The infrared sensors are evenly distributed inside the shielded chamber 5 to collect the temperature field changes on the surface of the lithium battery in real time. The infrared sensors work together with the detection circuit 4 to achieve simultaneous monitoring of the lithium battery temperature and electrical parameters.

[0021] The water tank 2 is a semi-enclosed cavity inside the base 1, filled with insulating oil as an emergency protective medium for the lithium battery. When abnormal temperature or electrical parameters of the lithium battery are detected, it can quickly immerse the lithium battery, isolating it from air and preventing spontaneous combustion. The platform 3 is horizontally set inside the water tank 2, and its bottom is connected to a hydraulic device. Driven by the hydraulic device, it can achieve stable vertical lifting and lowering, accurately raising the platform 3 to the testing position inside the shielded chamber 5, or quickly lowering it into the insulating oil in the water tank 2.

[0022] The surface of platform 3 has several holes. This hole design allows the insulating oil to quickly penetrate to all surfaces of the lithium battery when platform 3 is lowered and immersed in insulating oil, achieving all-round coverage of the lithium battery, improving the emergency protection effect, and avoiding the risk of spontaneous combustion of the lithium battery due to partial lack of contact with insulating oil. At the same time, the holes do not affect the stable placement of the lithium battery during the testing station, ensuring the stability of the testing process.

[0023] The detection line 4 is laid on the base 1 and extends to the detection station inside the shielded chamber 5. Its terminals can be flexibly connected to the positive and negative terminals of lithium batteries of different specifications to achieve electrical conduction with the lithium batteries. During the detection process, the voltage, current and other electrical parameters of the lithium batteries can be collected in real time to monitor whether there are any electrical abnormalities related to short circuits.

[0024] The shielding chamber 5 is an entirely enclosed structure with only a flip-top operating port at the front. When the flip-top is closed, it forms a complete shielded space, effectively blocking external electromagnetic signals from interfering with the internal rotating magnetic field and eddy current detection. This ensures the stability of the rotating magnetic field generated by the magnetic field structure 6 and the accuracy of eddy current induction and distortion detection within the lithium battery. Simultaneously, it prevents the energy generated by the internal rotating magnetic field and the impact of the electromagnetic catapult from radiating outwards, ensuring operational safety around the equipment. The front flip-top features a convenient opening and closing design, which, combined with the lifting and lowering of the platform 3, enables rapid loading and unloading of lithium batteries, improving testing efficiency.

[0025] See Figure 5 , Figure 6 and Figure 7 The magnetic field structure 6 is the core of the rotating magnetic field generation, including a support plate 61, an excitation coil 62 and a protective plate 63. There are four sets of support plates 61, which are fixedly installed on the front, back, left and right sides of the inner wall of the shielded cabin 5. Each set of support plates 61 has an annular groove, and the excitation coil 62 is embedded in the annular groove to achieve stable fixation.

[0026] The four excitation coils 62 are divided into two groups, front-to-back and left-to-right, with their axes orthogonal, providing a basis for the synthesis of the rotating magnetic field. Two sinusoidal alternating currents with equal amplitude, the same frequency, and a 90-degree phase difference are passed through the two groups of excitation coils 62 respectively. Utilizing the principle of electromagnetic induction, the magnetic fields generated by the two groups of excitation coils 62 synthesize into a uniform rotating magnetic field in the detection space within the shielded chamber 5. The magnetic field lines of this rotating magnetic field rotate uniformly in a plane perpendicular to the axes of the two coils, effectively penetrating the lithium battery casing and inducing eddy currents in its internal conductive structure. When there is damage inside the lithium battery, the discontinuous conductive structure in the damaged area leads to a distortion in the eddy current distribution. This distorted eddy current causes an abnormal local temperature rise in the area, providing a basis for subsequent infrared detection.

[0027] A protective plate 63 is laid on the outside of the support plate 61. It is made of a non-magnetic, non-conductive, high-resistivity rigid material. It will not attract or block the rotating magnetic field, ensuring that the magnetic field penetrates into the lithium battery without significant attenuation or distortion. It can also provide physical protection for the excitation coil 62, preventing damage to the coil from debris generated by the electromagnetic catapult. At the same time, it prevents the coil from making electrical contact with the external structure, ensuring the stable operation of the magnetic field structure.

[0028] See Figure 3 and Figure 4 The drive structure 8 is used to adjust the position and angle of the electromagnetic catapult 7 to adapt to the mechanical impact requirements of lithium batteries of different specifications and detection points. It includes a frame 81, an A-type module 82, a B-type module 83, a connecting frame 84, a spherical sleeve 85, and a guide ball 86. The electromagnetic catapult 7 is a mechanical impact actuator that can launch impact projectiles to apply mechanical impact to the lithium battery, simulating the collision conditions that the lithium battery is subjected to during transportation and use, and detecting the short circuit risk after impact.

[0029] The frame 81 is fixedly installed at the top inside the shielded cabin 5, serving as the load-bearing foundation for the drive structure. Modules A and B are symmetrically mounted on the frame 81, one above the other. Connecting brackets 84 are fixedly connected to the Y-axis module sliders of both modules. Spherical sleeves 85 are installed at the ends of the connecting brackets 84, allowing guide balls 86 to roll freely inside the sleeves. The electromagnetic catapult 7 passes through holes in the two guide balls 86. Its top is fixedly connected to the upper guide ball 86, while its bottom is slidably connected to the holes in the lower guide ball 86. This installation method provides room for angle adjustment of the electromagnetic catapult 7.

[0030] By synchronously adjusting the slider positions of I-beam type A module 82 and I-beam type B module 83, the electromagnetic catapult 7 can be moved horizontally to precisely align with the impact point of the lithium battery. By individually adjusting the slider position of I-beam type B module 83, the sliding engagement between the bottom of the electromagnetic catapult 7 and the lower guide ball 86, as well as the rolling of the guide ball 86 within the spherical sleeve 85, allows for flexible adjustment of the launch angle of the electromagnetic catapult 7, meeting the needs of mechanical impact detection at different angles. After completing the position and angle adjustment, the electromagnetic catapult 7 launches an impact projectile to apply a mechanical impact to the lithium battery, simulating actual collision conditions and providing conditions for subsequent detection of internal damage and short-circuit risk after impact on the lithium battery.

[0031] Several sets of infrared sensors are evenly distributed and installed around the detection space inside the shielded chamber 5, with their detection ends all facing the lithium battery support position on platform 3. This enables omnidirectional temperature monitoring of the lithium battery surface, eliminating blind spots. During the process of stimulating the lithium battery with a rotating magnetic field, the infrared sensors acquire real-time temporal temperature field images of the lithium battery surface, accurately capturing temperature changes, especially abnormal local temperature rises in damaged areas caused by eddy current distortion. By analyzing the temperature field images, the location of internal damage to the lithium battery can be identified and pinpointed. Simultaneously, the infrared sensors can monitor the overall temperature changes of the lithium battery in real time after mechanical impact and magnetic field excitation, promptly detecting abnormal temperature increases and providing temperature signal evidence for subsequent emergency protection.

[0032] The specific operation for using this device to detect short circuits in lithium batteries is as follows: Equipment startup and preparation: Start all systems of the device, control the hydraulic device to lift platform 3 to the preset testing position in the shielded cabin 5, check the operating status of the testing line 4, magnetic field structure 6, electromagnetic catapult 7, drive structure 8 and infrared sensor to ensure that all components are working properly; at the same time, confirm that the amount of insulating oil filling in the water tank 2 meets the standard and that the emergency protection function can be activated normally.

[0033] Lithium battery loading and circuit connection: Open the flip cover at the front of the shielded chamber 5, place the lithium battery to be tested stably in the center of the platform 3, and reliably connect the terminals of the detection circuit 4 to the positive and negative terminals of the lithium battery according to the positive and negative terminals of the lithium battery to ensure that the electrical parameters can be collected in real time; after the connection is completed, close the flip cover of the shielded chamber 5 to form a closed detection space.

[0034] Electromagnetic catapult positioning and mechanical impact: According to the testing requirements, the horizontal position and launch angle of the electromagnetic catapult 7 are adjusted by the drive structure 8 so that the impact projectile is accurately aimed at the impact point of the lithium battery; after the adjustment is completed, the electromagnetic catapult 7 is controlled to launch the impact projectile to apply a preset intensity of mechanical impact to the lithium battery, simulating the actual collision conditions of the lithium battery.

[0035] Rotating magnetic field excitation and dual-parameter synchronous detection: After the mechanical impact, sinusoidal alternating currents with equal amplitude, the same frequency, and a phase difference of 90 degrees are respectively passed through the two sets of excitation coils 62 of the magnetic field structure 6 to synthesize a uniform rotating magnetic field. The rotating magnetic field penetrates the lithium battery shell and induces eddy currents in its internal conductor structure. At the same time, the infrared sensor is activated to collect the time-series temperature field image of the lithium battery surface in real time, detect the surface temperature change, identify the abnormal local temperature rise caused by eddy current distortion due to internal damage, and locate the damage location. The detection line 4 synchronously monitors the voltage, current and other electrical parameters of the lithium battery in real time to determine whether there is a short circuit-related electrical abnormality.

[0036] Emergency Protection and Discharge: During the testing process, if the temperature detected by the infrared sensor or the electrical parameters monitored by the detection line 4 are abnormal and exceed the preset safety threshold, it is determined that the lithium battery has a short-circuit and spontaneous combustion risk. The equipment immediately activates the emergency protection program, controlling the hydraulic device to drive the platform 3 to descend rapidly, immersing the lithium battery in the insulating oil of the water tank 2 to isolate it from the air and prevent spontaneous combustion. If the temperature and electrical parameters of the lithium battery are normal during the testing process, it is determined that there is no obvious short-circuit risk. After the test is completed, the rotating magnetic field and infrared sensor are turned off first, then the platform 3 is controlled to remain in the testing position, the front cover of the shielding chamber 5 is opened, and the tested lithium battery is removed, completing a single testing process. After the equipment is reset, the next lithium battery testing operation can be performed.

[0037] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A lithium battery short-circuit detection device, characterized in that: It includes a base (1) and a water tank (2) installed inside the base (1). The water tank (2) is equipped with a liftable platform (3) and the water tank (2) is filled with insulating oil. When the lithium battery on the platform (3) has an abnormal temperature, it is lowered and introduced into the insulating oil to prevent it from spontaneously combusting. The base (1) is equipped with a detection line (4) for connecting the positive and negative electrodes of the lithium battery. The detection line (4) is connected to the positive and negative electrodes of the lithium battery to monitor the status of the lithium battery in real time. A shielding chamber (5) is installed on the base (1). The front cover of the shielding chamber (5) is a flip-top design to allow the lithium battery to be introduced and exported. The shielded cabin (5) is equipped with an electromagnetic catapult (7), and the electromagnetic catapult (7) adjusts its position and angle through the drive structure (8) so that the electromagnetic catapult (7) launches an impact projectile to collide with the lithium battery. The state of the lithium battery after the impact is detected by the detection line (4). The shielding chamber (5) is equipped with a magnetic field structure (6) inside, which generates a rotating magnetic field to penetrate the outer shell of the lithium battery and induce eddy currents in the conductor structure inside it; when there is damage inside the battery, the eddy current distribution in the damaged area is distorted, resulting in an abnormal local temperature rise in that area. The shielding chamber (5) is equipped with several sets of infrared sensors to detect the temperature of the lithium battery in real time after the impact.

2. The lithium battery short-circuit detection device according to claim 1, characterized in that: The bottom of the platform (3) is raised and lowered by a hydraulic device, and the surface of the platform (3) is provided with holes for insulating oil to pass through. After the platform (3) is immersed in the water pool (2), the insulating oil permeates the lithium battery through the holes on the surface of the platform (3).

3. The lithium battery short-circuit detection device according to claim 1, characterized in that: The drive structure (8) includes a frame (81) installed at the top of the inner side of the shielded cabin (5). A-type modules (82) and B-type modules (83) are symmetrically distributed vertically on the frame (81). Connecting frames (84) are installed on the Y-axis module sliders of both the A-type modules (82) and B-type modules (83). Spherical sleeves (85) are installed on the connecting frames (84), and the interior of the spherical sleeves (85) contains rollable guide balls (86). 6) The upper part is provided with holes for the installation of electromagnetic catapult (7), and the electromagnetic catapult (7) is respectively through the holes on the two guide balls (86). The upper guide ball (86) is fixed to the top of the electromagnetic catapult (7), and the bottom of the electromagnetic catapult (7) is slidably connected to the hole of the lower guide ball (86). The overall position of the electromagnetic catapult (7) is adjusted by the A-type module (82) and the B-type module (83), while the B-type module (83) adjusts the angle of the electromagnetic catapult (7).

4. The lithium battery short-circuit detection device according to claim 1, characterized in that: The magnetic field structure (6) includes a support plate (61) installed on the front, back, left and right sides of the inner wall of the shielded cabin (5). The support plate (61) has an annular groove, and an excitation coil (62) is embedded in the annular groove of the support plate (61). The excitation coils (62) at the front and back positions and the left and right positions are divided into two groups. Two sinusoidal alternating currents with equal amplitude, the same frequency and a phase difference of 90 degrees are simultaneously passed to the two groups of excitation coils (62). A uniform rotating magnetic field is synthesized in the shielded cabin (5) so that the magnetic field lines rotate at a constant speed in a plane perpendicular to the axes of the two coils.

5. A lithium battery short-circuit detection device according to claim 4, characterized in that: The two sets of excitation coils (62) are arranged opposite each other on opposite sides of the shielded cabin (5), so that the axes of the two sets of excitation coils (62) are orthogonal to form a rotating magnetic field.

6. A lithium battery short-circuit detection device according to claim 4, characterized in that: The outer side of the support plate (61) is covered with a protective plate (63), which is made of a non-magnetic, non-conductive, high resistivity rigid material, so that the magnetic field can penetrate without significant attenuation or distortion.

7. A method for detecting short circuits in lithium batteries, characterized in that, The lithium battery short-circuit detection device according to any one of claims 1-6 is operated as follows: S1: Lift the platform (3) to the detection position through the lifting and bearing mechanism, place the lithium battery on the platform (3), and connect the detection line (4). S2: Control the electromagnetic catapult (7) to adjust to the preset position and angle to apply mechanical impact to the lithium battery; S3: After the impact, the rotating magnetic field generated by the magnetic field structure (6) excites the lithium battery, and at the same time, the infrared sensor is used to collect the time-series temperature field image of its surface, detect the temperature change, identify and locate the internal damage location. S4: If the temperature or electrical parameters are detected to be abnormal and exceed the safety threshold, the platform (3) will be lowered immediately to immerse the lithium battery in insulating oil.

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