A metal-air battery safety test system

Abstract

The embodiment of the present invention discloses a metal-air battery safety test system, which includes: a battery holder for supporting a battery clamp; a battery sample as a test object, which is fixed by the battery clamp; an impactor ejection device, which is placed at a first set distance from the battery sample and is used to eject the impactor in a direction perpendicular to the battery plate; an impactor velocimeter for monitoring the speed of the impactor during the ejection process after ejecting from the impactor ejection port; a first camera, which is placed at a second set distance from the battery sample and is used to record the phenomenon that occurs in the battery sample after the impactor penetrates the battery sample, and the phenomenon is used to evaluate the safety level of the battery sample when it is hit by the impactor. By adopting the above technical solution, it is possible to truly simulate the test condition in which the impactor first penetrates the protective steel plate and then is embedded in the battery, and the test results generated have good distinguishability and repeatability.

Description

Technical Field

[0001] The invention relates to the technical field of batteries, and in particular to a metal-air battery safety test system. Background Art

[0002] Metal-air batteries are one of the representatives of green secondary batteries. They are non-toxic, pollution-free, high specific energy and stable performance. They have great development potential in many fields such as communication power supply and high-power reserve power supply. For ground combat troops, if metal-air batteries are used in military equipment, their working time will be significantly improved compared with traditional diesel generators, and their infrared characteristics will be significantly reduced. Since metal-air batteries are new technologies, their safety and reliability need to be further evaluated through more rigorous tests. At present, the test methods for testing battery safety through physical damage mainly include short circuit, drop, heating, discharge, salt spray and vibration tests in the current national standards. These four test methods have played an important role in their respective application fields, but they cannot effectively simulate the test conditions of high-speed impact or destruction of batteries when they are shot, and thus cannot fully and accurately evaluate the safety of batteries when they are shot. Summary of the invention

[0003] The embodiment of the present invention discloses a metal-air battery safety test system, which can truly simulate a test condition in which an impactor first penetrates a protective steel plate and then is embedded in the battery, and accurately evaluate the safety of the metal-air battery.

[0004] The embodiment of the present invention discloses a metal-air battery safety test system, the system comprising:

[0005] The shot unit, the shooting unit and the monitoring unit; wherein the shot unit includes: a battery bracket, a battery fixture and a battery sample; the shooting unit includes: an impactor ejection device, a bracket supporting the impactor ejection device and an impactor; the monitoring unit includes: a first camera and an impactor speed meter; wherein,

[0006] The battery bracket is used to support the battery clamp;

[0007] The battery sample is used as a test object and is fixed by the battery fixture;

[0008] The impactor ejection device is placed at a first set distance from the battery sample and is used to eject the impactor in a direction perpendicular to the battery plate; the impactor velocity meter is used to monitor the velocity of the impactor during the ejection process after ejecting from the impactor ejection port;

[0009] The first camera is placed at a second set distance from the battery sample, and is used to record phenomena occurring in the battery sample after the impactor penetrates the battery sample, and the phenomena are used to evaluate the safety level of the battery sample when it is hit by the impactor;

[0010] Among them, the phenomena that occur in the battery sample after being hit by the impactor include one or more of the following:

[0011] The battery surface is perforated by impact objects, the internal structure is changed, the battery leaks gas or liquid, the gas or liquid is toxic, an open flame occurs, and an explosion occurs after the open flame occurs;

[0012] Wherein, the battery clamp comprises a first baffle, a second baffle, a fixing block and a retractable bottom beam; Wherein,

[0013] There are four fixing blocks, two of which are fixed at the bottom of the first baffle plate to support the first baffle plate; the other two fixing blocks are fixed at the bottom of the second baffle plate to support the second baffle plate;

[0014] Along the ejection direction of the impactor, the first baffle and the second baffle are placed front and back opposite to each other and connected by the retractable bottom beam, and the area of ​​the first baffle is larger than that of the second baffle.

[0015] Optionally, the test system further includes:

[0016] A second camera is placed at a third set distance from the battery sample and is used to record changes in the battery from the start of the test to the end of the test;

[0017] The change phenomena include one or more of the following: being hit by an impact object, battery falling, liquid leakage, smoking, burning, explosion, color of leaked liquid, changes in the liquid and the bracket after contact, color of smoke, diffusion range, color of flame, shape of flame, diameter of fireball, length of flame and the number of fragments after explosion.

[0018] Optionally, the test system further includes:

[0019] A temperature sensor, including six temperature probes, for detecting temperature changes of the battery sample at different times after being hit by an impactor;

[0020] Among them, the measuring point of the first probe is arranged on the incident surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point of the second probe is arranged on the exit surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point of the third probe is arranged at the battery leakage valve; the measuring point of the fourth probe is arranged 12 cm directly above the battery; the measuring point of the fifth probe is arranged 18 cm directly above the battery; the measuring point of the sixth probe is arranged 30° to the left of the front of the battery and 14 cm away from the battery.

[0021] Optionally, the test system further includes:

[0022] The infrared imager is arranged 3 meters away from the battery sample, and the angle formed by the line connecting the infrared imager and the battery sample and the line connecting the impactor exit and the battery sample is 45°.

[0023] Optionally, the number of the impactor velocimeters is two, namely a first impactor velocimeter and a second impactor velocimeter arranged front and back along the impactor launching direction;

[0024] The distance between the first impactor velocity meter and the second impactor velocity meter is 1 meter;

[0025] The distance between the second impactor velocity meter and the impactor exit port is 1 meter;

[0026] The distance between the impactor exit port and the battery incident surface is 20 meters.

[0027] Optionally, the test system further includes:

[0028] The smoke tester is arranged at the fourth set distance from the battery sample. The angle formed by the line connecting the two points of the smoke tester and the battery sample and the line connecting the two points of the impactor and the battery sample is 45°. The smoke tester is used to detect whether the battery sample produces smoke when it is hit by the impactor, so as to determine the safety level of the battery sample when it is hit by the impactor.

[0029] Optionally, the smoke tester is also used to measure the transmittance of the light beam in the smoke by the attenuation effect of the smoke on the light intensity after the battery sample generates smoke, and to evaluate the smoke concentration level according to the light transmittance to determine the degree of damage to the battery sample.

[0030] Optionally, the first baffle and the second baffle are both made of frosted tungsten steel alloy.

[0031] Optionally, an angle formed by a line connecting two points of the first camera and the battery and a line connecting two points of the impactor outlet and the battery is 70°.

[0032] The technical solution provided by the embodiment of the present invention provides a battery safety test system, which includes a shot unit, a shooting unit and a monitoring unit; wherein the shot unit includes: a battery holder, a battery fixture and a battery sample; the shooting unit includes: an impactor ejection device, a holder supporting the impactor ejection device and an impactor; and the monitoring unit includes a first camera and an impactor velocity meter. Among them, the battery holder is used to support the battery fixture; the battery sample is used as a test object and is fixed by the battery fixture; the impactor ejection device is placed at a first set distance from the battery sample and is used to launch the impactor in a direction perpendicular to the battery plate; the impactor velocity meter is used to monitor the speed of the impactor during the launch process; the first camera is placed at a second set distance from the battery sample and is used to record the phenomenon of the battery sample after the impactor penetrates the battery sample. The system can realistically simulate the situation where the impactor first penetrates the steel plate used to protect the battery and then is embedded in the battery. By recording the phenomenon of the battery sample after the impactor penetrates the battery sample, the phenomenon can be used to evaluate the safety level of the battery sample when it is shot by the impactor, so that the test results generated have good repeatability and distinguishability.

[0033] The invention points of the present invention include:

[0034] 1. Construct a battery safety test system, which includes a shot unit, a shooting unit and a monitoring unit, wherein the shot unit includes: a battery holder, a battery clamp and a battery sample; the shooting unit includes: an impactor ejecting device, a holder supporting the impactor ejecting device and an impactor; the monitoring unit includes: a first camera and an impactor velocimeter; wherein the battery holder is used to support the battery clamp; the battery sample is used as a test object and is fixed by the battery clamp; the impactor ejecting device is placed at a first set distance from the battery sample and is used to launch an impactor in a direction perpendicular to the battery plate; the impactor velocimeter is used to monitor the speed of the impactor during the launching process; the first camera is placed at a second set distance from the battery sample and is used to record the phenomenon occurring in the battery sample after the impactor penetrates the battery sample, and the phenomenon is used to evaluate the safety level of the battery sample when it is shot by the impactor. The above-mentioned test system can realistically simulate the situation where an impactor first penetrates the steel plate used to protect the battery and then embeds into the battery, and effectively simulates the test condition where the battery is hit or destroyed at high speed when hit by an impactor. According to the test results, the safety of the battery when hit by an impactor can be accurately evaluated, which is one of the inventive points of the present invention.

[0035] 2. An embodiment of the present invention provides a battery clamp, which is mainly composed of a front baffle, a rear baffle, a fixing block and a telescopic bottom beam. There is a gap between the front baffle and the rear baffle for accommodating battery samples; the telescopic bottom beam is used to control the distance between the front baffle and the rear baffle to clamp the battery samples. By adopting this clamp, it can be ensured that the battery will not fall when being shot. At the same time, in order to make the clamp have good versatility for batteries of different shapes, it is helpful to realistically simulate the situation where the impact object first penetrates the steel plate used to protect the battery and then is embedded in the battery. This is one of the inventive points of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1a A structural diagram of a battery clamp provided by an embodiment of the present invention;

[0038] Figure 1b A schematic diagram of a battery clamp support device provided by an embodiment of the present invention;

[0039] Figure 2a A schematic diagram of the overall layout of a site provided by an embodiment of the present invention;

[0040] Figure 2b A schematic diagram of battery placement inside an explosion-proof cave provided by an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of a battery safety test system provided by an embodiment of the present invention;

[0042] Figure 4 A flowchart of a battery safety test method provided by an embodiment of the present invention;

[0043] Figure 5 A temperature measurement point layout diagram of a temperature sensor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that the terms "including" and "having" and any variations thereof in the embodiments of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0046] The technical solution provided by the embodiment of the present invention mainly evaluates the safety of the battery by analyzing the phenomena exhibited by the battery after being hit by an impact object. Since the battery may have open fire, explosion and other phenomena when being hit by an impact object, the technical solution provided by the embodiment of the present invention requires the preparation of a safe and reliable test site in advance.

[0047] See also Figure 2a . Figure 2a This is a schematic diagram of the overall layout of the site provided by the embodiment of the present invention. Figure 2a As shown in the figure, the site is divided into a safe area, an unsafe area, a dangerous area and a test area. People in the safe area can observe and take photos, or hide or operate the monitoring instrument trigger switch, etc.; the unsafe area is the location where the impactor is launched, and no other people are allowed to move around in the area except the shooter; the dangerous area refers to the area around the battery. After being hit by the impactor, the battery's own fragments and the impactor's fragments will splash around. No equipment can be placed in this area, and no people can stay; the test area is the area where the metal-air battery is shot by the impactor, mainly used to place the test monitoring unit (infrared imager, temperature sensor, high-speed camera, digital camera, bullet speed meter, infrared rangefinder), the shot unit (battery bracket, battery fixture, battery sample) and the shooting unit (impactor, impactor shooting device and the bracket supporting the impactor shooting device).

[0048] In addition, a safety fireproof and bulletproof wall is set up on the periphery of the site to prevent the impact object from flying out of the site and increasing safety hazards. A safety hole is set behind the shot battery. One is to prevent the impact object from flying into the hole when the impact object ejection device is calibrated to increase environmental safety; the other is to place the tested battery in the hole to prevent secondary combustion or explosion. A water reservoir is set up in the danger zone, which is mainly used to cool the iron battery bracket to improve the efficiency of the test. Fire extinguishing equipment is set up in the safe area, mainly to extinguish the fire source of the battery and its explosion fragments. Figure 2b This is a schematic diagram of the placement of batteries inside an explosion-proof cave provided by an embodiment of the present invention. Figure 2b As shown, in the explosion-proof cave, the metal-air battery is fixed on the support frame by a clamp.

[0049] After the site layout is completed, the battery safety test system can be established. This test system can truly simulate the process of metal-air batteries being hit by impactors, especially the test condition where the impactor first penetrates the protective steel plate and then embeds into the battery. For details, please refer to Figure 3 .

[0050] Figure 3 A schematic diagram of a battery safety test system provided by an embodiment of the present invention. Figure 3 As shown, the test system provided in this embodiment specifically includes: a shot unit, a shooting unit and a monitoring unit; wherein the shot unit includes: a battery bracket (not shown in the figure), a battery clamp (not shown in the figure) and a battery sample 3; the shooting unit includes: an impactor ejection device 8, a bracket supporting the impactor ejection device and an impactor (not shown in the figure); the monitoring unit includes a first camera 5 and an impactor speed meter 7; wherein,

[0051] A battery bracket, used to support the battery fixture;

[0052] The battery sample 3 is used as a test object and is fixed by a battery clamp, and the battery clamp is set in the explosion-proof hole 2. In this embodiment, the battery sample is a metal air battery;

[0053] The impactor ejection device 8 is placed at a first set distance from the battery sample 3 and is used to eject the impactor in a direction perpendicular to the battery plate; the impactor velocity meter 7 is used to monitor the velocity of the impactor during the ejection process after the impactor is ejected from the ejection port of the impactor ejection device 8;

[0054] The first camera 5 is placed at a second set distance from the battery sample 3, and is used to record the phenomenon that occurs in the battery sample 2 after the impactor penetrates the battery sample 3, and the phenomenon is used to evaluate the safety level of the battery sample 3 when it is hit by the impactor.

[0055] In this embodiment, the positions of each unit are preferably: the distance between the impactor outlet of the impactor ejection device and the incident surface of the battery is 20 meters; the distance between the impactor outlet and the impactor velocity meter is 1 meter; the distance between the two rangefinders is 1 meter; the distance between the first camera and the battery is 2.5 meters, and the angle formed by the line connecting the first camera 5 and the battery sample 3 and the line connecting the impactor outlet and the battery is about 70°. The smoke tester 9 is arranged at the fourth set distance from the battery sample, and the angle formed by the line connecting the smoke tester and the battery sample and the line connecting the impactor outlet and the battery sample is 45°. The probe monitoring line of the temperature sensor 1 is inserted from the underground and arranged on the inner wall of the explosion-proof cave and the inside of the battery at the same time, and is firmly fixed. In addition, the test system provided by the embodiment of the present invention also includes: an infrared rangefinder 4, which is used to test the distance between each unit. In addition, the test system provided by the embodiment of the present invention further includes a second camera 6, which is placed at a third set distance from the battery sample and is used to record the changes in the battery during the entire process from the start of the test to the end of the test.

[0056] It should be noted that the placement of each unit in the test system provided in this embodiment can also be arbitrarily set according to empirical values, and this embodiment does not specifically limit this. The above test system can truly simulate the situation where the impactor first penetrates the steel plate used to protect the battery and then embeds into the battery, and effectively simulates the test condition where the battery is hit or destroyed at high speed when it is hit by an impactor. According to the test results, the safety of the battery when it is hit by an impactor can be accurately evaluated, which is one of the inventive points of the present invention.

[0057] In this embodiment, the first camera is a high-speed camera. Compared with ordinary cameras, high-speed cameras have faster continuous shooting speeds, which can reach dozens or even thousands of frames per second, and the resolution of each frame is higher than that of video cameras. In this embodiment, the basic condition for evaluating the battery safety level is that the impactor penetrates the battery or is embedded in the battery, and the main function of the high-speed camera is to prove that the impactor has indeed penetrated the battery or is embedded in the battery. In addition, during the test, some batteries may produce micro flames. It is not enough to view this phenomenon only through ordinary cameras. Therefore, it is necessary to use high-speed cameras to determine whether the micro flames are generated by the battery or the impactor.

[0058] In this embodiment, the battery sample, i.e. the object of the shooting test, is a metal-air battery, which can be a zinc-air battery, a magnesium-air battery, an aluminum-air battery, and a lithium-air battery. In terms of capacity, the energy of the air battery of each metal material is specified to be 500Wh, which is convenient for the horizontal evaluation of the safety performance of the metal-air battery. In terms of the state of charge, the power of the single cell and the module battery is 100%, 50%, and 0%, which is convenient for the vertical evaluation of the safety performance of the same battery under different power conditions.

[0059] In order to ensure that the battery does not fall when it is shot, and also to make the clamp have good versatility for batteries of different shapes, this embodiment provides a battery clamp, which includes a first baffle, a second baffle, a fixing block and a retractable bottom beam; wherein,

[0060] There are four fixing blocks, two of which are fixed at the bottom of the first baffle plate to support the first baffle plate; the other two fixing blocks are fixed at the bottom of the second baffle plate to support the second baffle plate;

[0061] The first baffle plate and the second baffle plate are placed opposite to each other and connected through the retractable bottom beam, and the area of ​​the first baffle plate is larger than that of the second baffle plate.

[0062] Specifically, Figure 1a A structural diagram of a battery clamp provided by an embodiment of the present invention, Figure 1b A schematic diagram of a battery clamp support device provided by an embodiment of the present invention. Figure 1b As shown, the supporting device of the battery clamp includes supporting members placed opposite to each other perpendicular to the ground, and the tops of the two supporting members are provided with concave slide grooves. Figure 1a As shown, the battery clamp is mainly composed of first baffles ( Figure 1a The front baffle in the middle), the second baffle ( Figure 1a The front baffle is slightly larger and is used to cover the metal-air battery to simulate its protective layer. During the test, the impactor will first pass through the front baffle. The rear baffle is slightly smaller and is used to support the rear of the battery to fix it on the fixture. Two fixing blocks are welded at the bottom of the front and rear baffles for easy embedding. Figure 1b In the slide slot of the support device shown, there are two retractable bottom beams connecting the lower sides of the front and rear baffles. The retractable bottom beams can be adjusted accordingly for different types of metal-air batteries. The battery installation process on the fixture is as follows: the battery sample is placed on the bottom beam between the front and rear baffles, and the front and rear baffles are clamped to the battery sample by sliding the fixed block in the slide slot and retracting the bottom beam.

[0063] Specifically, the bottom beam frame is made of high temperature resistant material; the front and rear baffles are made of tungsten steel alloy frosted material to increase the friction with the metal air battery, so that the battery can be placed firmly.

[0064] After the site and test system are arranged, the battery firing test can be started. This embodiment provides a test method that is highly operable and convenient for evaluating the safety of different metal-air batteries after firing, and the test results produced have good repeatability and distinguishability. Figure 4 .

[0065] Figure 4A flowchart of a battery safety test method provided by an embodiment of the present invention is as follows: Figure 4 As shown, before the test actually starts, the battery can be charged according to the test regulations, and the impactor and impactor ejection device can be selected. After the selection is completed, the weather conditions need to be judged. If there is rain, snow or strong wind, the test ends. When the weather conditions are good, the test can continue.

[0066] Before the test, the integrity of each instrument must be checked, and the verified intact instruments must be placed in place and anti-collision glass must be installed. Then install the battery, baffle and text sensor probe on the battery fixture. After the installation is completed, if it is determined that the battery has abnormal phenomena such as natural or explosive phenomena, the battery sample must be replaced, that is, the battery installation operation must be performed again. If no abnormal phenomena occur after the safety is completed, the switches of monitoring instruments such as temperature sensor receivers, high-speed cameras, video cameras, infrared thermal imagers, etc. are turned on for monitoring. The shooting personnel start the shooting operation after hiding. The specific shooting process can be: aiming at the geometric center of the battery for shooting (so that the impactor penetrates from a direction perpendicular to the battery plate, and the impactor shooting speed is not less than 750m / s). If the battery is not hit, the shooting operation is repeated; if the battery is hit, the test phenomenon is recorded, and after the data in each monitoring instrument no longer changes, the data in the monitoring instrument is exported, and the instrument switch is turned off. The test conclusion is obtained by analyzing the test phenomenon and test data, such as the battery bulging size, the incident and exit hole diameters, etc.

[0067] In this embodiment, in order to facilitate the evaluation of the safety of the battery, the test phenomena that may occur after the battery is penetrated by an impact object can be used to divide the safety level from light to heavy into five levels: level 2 safety, level 1 safety, level 1 danger, level 2 danger, and level 3 danger. The test phenomena corresponding to different safety levels are shown in Table 1 below. Combined with Table 1, the safety level of the metal-air battery can be obtained through the test phenomena.

[0068] Table 1 Comparison table of safety level and test phenomenon

[0069]

[0070] The methods for judging the test phenomena are as follows: (1) If the battery is perforated by an impactor, it can be judged by naked eye observation. (2) If the internal structure of the battery is uneven or distorted, a gamma-ray cutting tool can be used to cut the battery along the direction of the impactor to observe the damage characteristics of the internal structure of the battery; (3) If there is gas or liquid leakage, the pre- and post-test weighing method and smoke tester method can be used; (4) For open flames and explosions, a high-speed camera can be used for photo identification.

[0071] Specifically, for metal-air batteries, the safety level can be determined by using the following safety test methods:

[0072] If it is detected that the impact object has not been shot into the battery, the battery has not leaked, and the internal structure of the battery has not changed, the safety level of the battery stack is determined to be level 2 safety;

[0073] If it is detected that the battery surface is perforated by an impact object, and the battery leakage capacity reaches a first preset threshold, and the battery content structure is changed, the battery safety level is determined to be level one safety;

[0074] If a perforation of the battery surface by an impact object is detected, and the leakage capacity of the battery stack reaches a second preset threshold, the safety level of the battery stack is determined to be a first-level danger; wherein the first preset threshold is less than the second preset threshold;

[0075] If a hole is detected on the battery surface due to an impact, and the battery is detected to be smoking, the battery safety level is determined to be level 2 danger;

[0076] If perforations are detected on the battery surface caused by impact objects, and open flames and explosions are detected in the battery, the battery's safety level is determined to be level three.

[0077] On the basis of the above embodiments, when evaluating the safety of metal-air batteries in shooting tests, experimental phenomenon test methods, battery temperature test methods and smoke density test methods may also be used. Each method is described in detail below.

[0078] Among them, regarding the test phenomenon test method, specifically, a second camera, i.e., a digital camera, is used to record the test phenomenon, and the safety level of the battery is determined by analyzing the test phenomenon. Figure 3 As shown, the test system provided by the embodiment of the present invention also includes a second camera, which is placed at a third set distance from the battery sample, and is used to record the changes in the battery during the entire process from the start of the test to the end of the test. The second camera can be a digital camera, and the third set distance can be 2.5 meters. The digital camera mainly records the entire process of the shooting test, which may include being hit by an impactor, whether the battery surface is punctured by the impactor, the battery falling, leaking, smoking, burning, exploding, the color of the leaked liquid, the changes in the liquid and the bracket after contact, the color of the smoke, the diffusion range, the color of the flame, the shape of the flame, the diameter of the fireball, the length of the flame, the explosion power, and the number of fragments after the explosion.

[0079] Among them, regarding the battery temperature testing method, this embodiment adopts the use of a K-type temperature sensor for testing. On the basis of the above-mentioned embodiment, the temperature sensor provided in the embodiment of the present invention may be a K-type temperature sensor, which includes six temperature probes for detecting the temperature changes of the battery sample at different times after being hit by an impactor. The temperature index detected by the temperature sensor and the above-mentioned test phenomenon can both be used as standards for evaluating battery safety. Specifically, using the detected temperature index, batteries within the same safety level can be further classified in detail, that is, the safety level of the battery can be roughly divided according to the test phenomenon, and then the safety level of the battery can be finely divided according to the temperature index. The temperature index and the test phenomenon are interdependent and mutually confirmed, so that the test results have good distinguishability, which is one of the inventive points of the present invention. Among them, the temperature sensor provided in this embodiment may preferably be a K-type temperature sensor. For the layout diagram of the detection points of the temperature sensor, please refer to . Figure 5 .

[0080] like Figure 5 As shown, the measuring point a of the first probe of the K-type temperature sensor is arranged on the incident surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point b of the second probe is arranged on the exit surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point c of the third probe is arranged at the battery leakage valve; the measuring point d of the fourth probe is arranged 12 cm above the battery, because according to the test data, 12 cm is the flame core of the large battery flame jet and the outer flame of the small battery flame jet. The measuring point e of the fifth probe is arranged 18 cm above the battery, because according to the test data, 18 cm is the outer flame of the large battery flame jet; the measuring point f of the sixth probe is arranged 30° to the left of the front of the battery and 14 cm away from the battery. This is set because according to the test data, 14 cm is the outer flame of the flame jet of most battery bullet holes.

[0081] In this embodiment, the contents that can be analyzed by the K-type temperature sensor include: temperature curve trend, injection point temperature, ignition point temperature, temperature rise period, temperature stable period, temperature drop period, duration of different temperature stages, maximum temperature, minimum temperature and average temperature.

[0082] On the basis of the above embodiment, the test system provided by the embodiment of the present invention also includes: an infrared imager (shown in the figure), which is arranged 3 meters away from the battery sample, and the angle formed by the line connecting the two points of the battery sample and the line connecting the impactor exit and the two points of the battery sample is 45°, which is used to measure temperature data.

[0083] Among them, regarding the smoke test method, after the battery produces smoke and smoke, the transmittance of the light beam in the smoke can be measured by the attenuation effect of the smoke on the light intensity, and the smoke concentration level can be evaluated according to the light transmittance. Specifically, the moment when the impactor enters the battery can be used as the test zero point, and the transmittance value starting to increase from the minimum can be recorded as the test end point. The acquisition frequency of the smoke tester is 1 time / second, and the curves of the above four indicators can be drawn. By comparing the highest point, the lowest point, the curve trend, the curve rise and decrease rate of the four indicator curves of different batteries, the degree of battery damage can be obtained. It is particularly pointed out that in order to ensure the accuracy of the smoke test instrument value, the test must be carried out under clear weather conditions without rain, snow or wind.

[0084] On the basis of the above-mentioned embodiment, in order to increase the integrity of the parameters of the shooting test object, the embodiment of the present invention further provides a size measurement method, which mainly includes the following three aspects:

[0085] (1) Use a ruler to measure the length, width, height and other dimensions of the battery.

[0086] (2) Use an infrared rangefinder to measure the size of the image exported by the field test instrument, and then calculate it according to the corresponding relationship of the scale. Specifically, the infrared rangefinder can measure the flame size and smoke diffusion range in the video image, and calculate the theoretical values ​​of parameters such as flame length and smoke diffusion range according to the scale.

[0087] (3) The indirect measurement method is used to measure the size of the bullet entry and exit holes of the battery. First, methyl red and tannic acid reagents are applied to the outer edge of the bullet hole, and then the print is printed on rice paper. After the print on the rice paper is dry, the size of the largest outer edge of the print is measured with a vernier caliper.

[0088] This embodiment is set up in this way, and more detailed indicators under the safety level can be obtained, such as smoke diffusion range and flame length, etc. These indicators can be used to rank the dangerousness of batteries of the same safety level, so as to meet the adaptability requirements of different application scenarios, which is one of the inventive points of the present invention. For example: two batteries were subjected to a shooting test. For user A, he only needs to know the safety level of the battery, so he does not need to measure subtle parameters such as flame length, and only needs to observe the phenomenon to judge the level; for user B, he wants to know which battery is safer, so he needs to compare subtle parameters such as smoke diffusion range and flame length.

[0089] On the basis of the above embodiments, in order to facilitate the analysis of the test phenomenon, the data during the test process can be recorded. Specifically, the following data can be recorded: basic parameters of the battery (battery number, battery type, battery capacity, battery power and battery manufacturer), test conditions (battery serial number, penetration baffle thickness, tungsten steel plate thickness, shooting distance, impactor type, impactor speed), meteorological conditions (atmospheric temperature, relative humidity, atmospheric pressure, wind speed, wind direction and weather conditions), test phenomena during the test, battery surface temperature, battery surface maximum temperature and average temperature, battery bullet hole size and test conclusions, etc.

[0090] The technical solution provided in this embodiment provides a test system for the safety of metal-air batteries, which includes a shot unit, a shooting unit and a monitoring unit; wherein the shot unit includes: a battery holder, a battery fixture and a battery sample; the shooting unit includes: an impactor ejection device, a bracket supporting the impactor ejection device and an impactor; and the monitoring unit includes a first camera and an impactor velocimeter. Among them, the battery holder is used to support the battery fixture; the battery sample is used as a test object and is fixed by the battery fixture; the impactor ejection device is placed at a first set distance from the battery sample and is used to launch the impactor in a direction perpendicular to the battery plate; the impactor velocimeter is used to monitor the speed of the impactor during the launch process; the first camera is placed at a second set distance from the battery sample and is used to record the phenomenon that occurs in the battery sample after the impactor penetrates the battery sample. The system can realistically simulate the situation that the impactor first penetrates the steel plate used to protect the battery and then is embedded in the battery. By recording the phenomenon that occurs in the battery sample after the impactor penetrates the battery sample, the phenomenon can be used to evaluate the safety level of the battery sample when it is shot by the impactor, so that the test results generated have good repeatability and distinguishability.

[0091] The battery safety test system disclosed in the embodiment of the present invention is introduced in detail above. The principle and implementation mode of the present invention are explained in this article by using specific examples. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A metal-air battery safety test system, characterized in that: include: The shot unit, the shooting unit and the monitoring unit; wherein the shot unit includes: a battery bracket, a battery fixture and a battery sample; the shooting unit includes: an impactor ejection device, a bracket supporting the impactor ejection device and an impactor; the monitoring unit includes: a first camera and an impactor speed meter; wherein, The battery bracket is used to support the battery clamp; The battery sample is used as a test object and is fixed by the battery fixture, and the battery sample is a metal-air battery; The impactor ejection device is placed at a first set distance from the battery sample and is used to eject the impactor in a direction perpendicular to the battery plate; the impactor velocimeter is used to monitor the speed of the impactor during the ejection process; The first camera is placed at a second set distance from the battery sample, and is used to record phenomena occurring in the battery sample after the impactor penetrates the battery sample, and the phenomena are used to evaluate the safety level of the battery sample when it is hit by the impactor; Among them, the phenomena that occur in the battery sample after being hit by the impactor include one or more of the following: The battery surface is perforated by impact objects, the internal structure is changed, the battery leaks gas or liquid, the gas or liquid is toxic, an open flame occurs, and an explosion occurs after the open flame occurs; The safety level is determined by the following safety test method: If it is detected that the impact object has not been shot into the battery, the battery has not leaked, and the internal structure of the battery has not changed, the safety level of the battery stack is determined to be level 2 safety; If it is detected that the battery surface is perforated by an impact object, and the battery leakage capacity reaches a first preset threshold, and the battery content structure is changed, the battery safety level is determined to be level one safety; If a perforation of the battery surface by an impact object is detected, and the leakage capacity of the battery stack reaches a second preset threshold, the safety level of the battery stack is determined to be a first-level danger; wherein the first preset threshold is less than the second preset threshold; If a hole is detected on the battery surface due to an impact, and the battery is detected to be smoking, the battery safety level is determined to be level 2 danger; If a perforation is detected on the battery surface caused by an impact object, and an open fire and explosion are detected in the battery, the battery safety level is determined to be level three danger; Wherein, the battery clamp comprises a first baffle, a second baffle, a fixing block and a retractable bottom beam; Wherein, There are four fixing blocks, two of which are fixed at the bottom of the first baffle plate to support the first baffle plate; the other two fixing blocks are fixed at the bottom of the second baffle plate to support the second baffle plate; Along the ejection direction of the impactor, the first baffle and the second baffle are successively placed opposite to each other and connected by the retractable bottom beam, and the area of ​​the first baffle is larger than that of the second baffle; The test system also includes: The temperature sensor includes six temperature probes, which are used to detect the temperature changes of the battery sample at different times after being hit by the impact object, and use the detected temperature index to further classify the batteries within the same safety level, that is, roughly classify the safety level of the battery according to the test phenomenon, and then finely classify the safety level of the battery according to the temperature index; Among them, the measuring point of the first probe is arranged on the incident surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point of the second probe is arranged on the exit surface of the impactor, 3 cm away from the geometric center of the battery; the measuring point of the third probe is arranged at the battery leakage valve; the measuring point of the fourth probe is arranged 12 cm above the battery; the measuring point of the fifth probe is arranged 18 cm above the battery; the measuring point of the sixth probe is arranged 30° to the left of the front of the battery and 14 cm away from the battery; The test system also includes: The smoke tester is arranged at a fourth set distance from the battery sample, and the angle formed by the line connecting the two points of the smoke tester and the battery sample and the line connecting the impactor outlet and the two points of the battery sample is 45°. The smoke tester is used to detect whether the battery sample generates smoke when it is hit by the impactor, so as to determine the safety level of the battery sample when it is hit by the impactor; The smoke tester is also used to measure the transmittance of the light beam in the smoke through the attenuation effect of the smoke on the light intensity after the battery produces smoke and smoke emission, and to evaluate the smoke concentration level according to the light transmittance.

2. The system according to claim 1, characterized in that The test system also includes: A second camera is placed at a third set distance from the battery sample, and is used to record changes in the battery during the entire process from the start of the test to the end of the test; The change phenomena include one or more of the following: being hit by an impact object, battery falling, liquid leakage, smoking, burning, explosion, color of leaked liquid, changes in the liquid and the bracket after contact, color of smoke, diffusion range, color of flame, shape of flame, diameter of fireball, length of flame and the number of fragments after explosion.

3. The system according to claim 1, characterized in that There are two impactor velocimeters, namely a first impactor velocimeter and a second impactor velocimeter arranged in front and behind the impactor launching direction; The distance between the first impactor velocity meter and the second impactor velocity meter is 1 meter; The distance between the second impactor velocity meter and the impactor exit port is 1 meter; The distance between the impactor exit port and the battery incident surface is 20 meters.

4. The system according to claim 1, characterized in that The first baffle plate and the second baffle plate are both made of frosted tungsten steel alloy.

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