A lithium-ion battery fire and deflagration test device

Abstract

The present invention discloses a lithium-ion battery fire and deflagration test device, comprising an isolation cavity, wherein the outer wall of the isolation cavity is evenly provided with pairs of observation windows along its circumference, a burner is installed at the bottom of the isolation cavity, and the nozzle end of the burner is arranged upward, and the input end of the burner is provided with a fuel input pipe and an oxygen input pipe with adjustable flow, and a battery cell fixing unit is arranged above the burner, and the burner and the battery cell fixing unit are wrapped in a cylindrical transparent combustion chamber. The beneficial effects of the present invention are: the flame generated by the burner is used to directly heat the lithium battery to ignite and deflagrate, and by adjusting the fuel and oxygen input flow of the burner, the smoke composition and combustion temperature in the transparent combustion chamber can be controlled, so as to facilitate the simulation of the ignition and flame propagation characteristics of the lithium battery under the real fire condition, and further, by utilizing the transparent characteristics of the observation window and the transparent combustion chamber, the deflagration phenomenon of the lithium-ion battery can be optically measured under the simulated fire condition.

Description

Technical Field

[0001] The invention relates to the technical field of lithium ion battery fire safety testing devices, and in particular to a lithium ion battery fire deflagration testing device. Background Art

[0002] The materials that make up lithium-ion batteries have inherent properties of being flammable and explosive. During the use of batteries, thermal runaway such as overcharging, impact, short circuit, and open flame heating can easily cause battery fire and explosion. The increasingly frequent lithium-ion battery explosion accidents have caused great harm to people's property, environment, and personal safety. Therefore, it is necessary to test the fire and explosion behavior of lithium-ion batteries to provide reference data for the development and production of safer lithium-ion batteries.

[0003] The various lithium-ion battery fire and explosion test devices that have been developed can be roughly divided into two categories. One is to simulate the thermal runaway of the charging and discharging process, focusing on measuring the impact of charging and discharging conditions on the thermal runaway of the battery. It uses a special sealed battery thermal runaway explosion test box to measure the surface temperature of the battery when it is out of control, the battery mass loss and heat generation during the runaway combustion. Generally, only one observation window is set on the front of the box, which is not convenient for optical measurement of the deflagration phenomenon; the other type uses electric heating wire winding directly or electric heating wire furnace preheating iron plate to indirectly heat the battery to achieve thermal runaway, and is carried out in a relatively large semi-open combustion test space, focusing on testing the surface temperature of the battery fire and the flame propagation characteristics of thermal runaway. Since this type of device is basically carried out in still air, the ignition and deflagration of a single battery are affected by the ambient temperature and atmosphere conditions, and it is impossible to obtain the battery deflagration phenomenon and law under the simulated fire condition (high temperature smoke environment). In summary, the above two devices have their own defects, and neither can perform optical measurement of the deflagration phenomenon of lithium-ion batteries under simulated fire conditions. Summary of the invention

[0004] In view of the above problems, the present invention proposes a lithium-ion battery fire and deflagration testing device, which mainly solves the problem that the existing testing device cannot perform optical measurement of the deflagration phenomenon of the lithium-ion battery under a simulated fire condition.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0006] A lithium-ion battery fire and deflagration test device comprises an isolation cavity and a cover body installed on the top of the isolation cavity, wherein the outer wall of the isolation cavity is evenly provided with pairs of observation windows along its circumference, a burner is installed at the bottom of the isolation cavity, and the nozzle end of the burner is arranged upward, and the input end of the burner is provided with a fuel input pipe and an oxygen input pipe with adjustable flow, and a battery cell fixing unit is arranged above the burner, and the burner and the battery cell fixing unit are wrapped in a cylindrical transparent combustion chamber, and the upper end of the transparent combustion chamber vertically passes through the surface of the cover body.

[0007] In some embodiments, a cylindrical transparent isolation chamber is further included, and the transparent isolation chamber is coaxially sleeved on the outer side of the nozzle end of the burner.

[0008] In some embodiments, the battery cell fixing unit includes a circular ring base, a support rod mirror-imaged on the upper end surface of the circular ring base, and a battery cell clamp fixed to the upper ends of the two support rods, wherein the circular ring base is coaxially sleeved on the outer side of the transparent isolation cavity.

[0009] In some embodiments, a heat spreader is horizontally fixed between the two support rods, and the lower end surface of the heat spreader is against the edge of the upper port of the transparent isolation cavity.

[0010] In some embodiments, the vapor chamber is a honeycomb ceramic structure.

[0011] In some embodiments, the outer edge of the vapor chamber transitionally matches the inner wall of the transparent combustion chamber.

[0012] In some embodiments, the height of the upper port of the transparent isolation cavity is at least 10 mm greater than the height of the nozzle end of the burner.

[0013] In some embodiments, a fixed plate is provided on the inner bottom of the isolation cavity, a through hole is provided at the center of the fixed plate for avoiding the burner, and the through hole is expanded outward to cooperate with the inner bottom of the isolation cavity to form a step, and the step is used to accommodate the transparent isolation cavity, the annular base and the transparent combustion chamber which are coaxially arranged in sequence from the inside to the outside.

[0014] In some embodiments, the cover is detachably mounted on the top of the isolation cavity.

[0015] In some embodiments, the observation window includes a mounting seat protruding radially along the isolation cavity, and a transparent plate fixed to an inner edge of the mounting seat.

[0016] The beneficial effects of the present invention are as follows: a burner and a battery cell fixing unit are arranged in an isolation cavity, and a cylindrical transparent combustion chamber is used to wrap the burner and the battery cell fixing unit, the transparent combustion chamber is used as the main place for lithium battery combustion, and the flame generated by the burner is used to directly heat the lithium battery to ignite and deflagrate. By adjusting the fuel input flow rate and oxygen input flow rate of the burner, the smoke composition and combustion temperature in the transparent combustion chamber can be controlled, thereby simulating the ignition and flame propagation characteristics of the lithium battery under real fire conditions. Furthermore, the paired observation windows arranged on the periphery of the isolation cavity are used as observation points. By utilizing the transparent characteristics of the observation windows and the transparent combustion chamber, the deflagration phenomenon of the lithium-ion battery can be optically measured under simulated fire conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A three-dimensional diagram of a lithium-ion battery fire and deflagration test device disclosed in an embodiment of the present invention;

[0018] Figure 2 A front cross-sectional view of a lithium-ion battery fire and deflagration test device disclosed in an embodiment of the present invention;

[0019] Figure 3 An exploded view of a cell fixing unit, a transparent isolation cavity, and a heat spreader disclosed in an embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the combination of the battery cell fixing unit, the transparent isolation cavity and the heat spreader disclosed in the embodiment of the present invention;

[0021] Among them: 1-isolation cavity, 2-cover, 3-observation window, 4-burner, 5-battery cell fixing unit, 6-transparent combustion chamber, 7-transparent isolation cavity, 8-heat plate, 9-fixing plate, 501-circular base, 502-support rod, 503-battery cell fixture. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the content of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all the contents.

[0023] This embodiment provides a lithium-ion battery fire and deflagration test device, such as Figure 1 and 2 As shown, it includes an isolation cavity 1 and a cover body 2 installed on the top of the isolation cavity 1. The outer wall of the isolation cavity 1 is evenly provided with pairs of observation windows 3 along its own circumference. A burner 4 is installed at the bottom of the isolation cavity 1, and the nozzle end of the burner 4 is arranged upward. The input end of the burner 4 is provided with a fuel input pipe and an oxygen input pipe with adjustable flow rates. A battery cell fixing unit 5 is arranged above the burner 4. The burner 4 and the battery cell fixing unit 5 are wrapped in a cylindrical transparent combustion chamber 6. The upper end of the transparent combustion chamber 6 vertically passes through the surface of the cover body 2, and the cover body 2 is used to radially limit the transparent combustion chamber 6.

[0024] It should be noted that the above-mentioned "paired observation windows 3" means that every two mirror-symmetrical observation windows 3 serve as a pair of observation windows 3. Figure 1For example, four observation windows 3 are arranged in the figure. According to the principle of uniform arrangement along the circumference, the adjacent observation windows 3 are spaced 90° apart, so every two mirror-symmetrical observation windows 3 serve as a pair of observation windows 3. The light source sent by the transmitting end of the optical instrument enters from one of the observation windows 3, and is emitted from the other paired observation window 3, and is received by the receiving end of the optical instrument. The above-mentioned burner 4 can be completely located inside the isolation cavity 1, or only the nozzle end part can be located inside the isolation cavity 1, and the rest can be located outside the isolation cavity 1.

[0025] In this embodiment, a burner 4 and a battery cell fixing unit 5 are arranged in the isolation cavity 1, and a cylindrical transparent combustion chamber 6 is used to wrap the burner 4 and the battery cell fixing unit 5. The transparent combustion chamber 6 is used as the main place for the combustion of the lithium battery. The flame generated by the burner 4 is used to directly heat the lithium battery to ignite and deflagrate. By adjusting the fuel input flow rate and oxygen input flow rate of the burner 4, the smoke composition and combustion temperature in the transparent combustion chamber 6 can be controlled, thereby simulating the ignition and flame propagation characteristics of the lithium battery under a real fire condition. Furthermore, the paired observation windows 3 arranged on the side of the isolation cavity 1 are used as observation points. The transparent characteristics of the observation windows 3 and the transparent combustion chamber 6 can be used to optically measure the deflagration phenomenon of the lithium-ion battery under a simulated fire condition.

[0026] When the above device is in use, the cover body 2 needs to be opened and the transparent combustion chamber 6 needs to be pulled out from the isolation chamber 1 until the battery cell fixing unit 5 is exposed. After the lithium battery is fixed in the battery cell fixing unit 5, the cover body 2 and the transparent combustion chamber 6 need to be installed back to their original positions, and then the burner 4 needs to be started to heat the lithium battery.

[0027] In an optional embodiment, a cylindrical transparent isolation chamber 7 is also included. The transparent isolation chamber 7 is coaxially sleeved on the outside of the nozzle end of the burner 4. The function of the transparent isolation chamber 7 is to concentrate and restrain the flame generated by the burner 4 in the early stage of lithium battery explosion to prevent the flame from spreading everywhere. In addition, by utilizing the transparent characteristics of the transparent isolation chamber 7, the light waves of the flame generated by the burner 4 can also pass through the transparent isolation chamber 7, the annular base 501 and the transparent combustion chamber 6 in sequence, and propagate to the outside of the isolation chamber 1, so that the ignition process of the burner 4 can be visualized, which is convenient for confirming whether the device is successfully started.

[0028] The battery cell fixing unit 5 can be any device fixed above the burner 4 and has no motion interference with the transparent isolation cavity 7. In one example, Figure 3 and 4As shown, the battery cell fixing unit 5 includes a circular base 501, a support rod 502 mirror-set on the upper end surface of the circular base 501, and a battery cell fixture 503 fixed on the upper ends of the two support rods 502, wherein the circular base 501 is coaxially sleeved on the outside of the transparent isolation cavity 7. In this scheme, the circular base 501 is used to avoid the transparent isolation cavity 7 and is inserted along the outer wall of the transparent isolation cavity 7, and the support rod 502 is used to raise the height of the battery cell fixture 503 so that the battery cell fixture 503 is located above the burner 4. The above-mentioned battery cell fixture 503 can be any form of fixing device, including but not limited to elastic fixtures, rigid fixtures or chuck fixtures. At the same time, on the basis of this scheme, since the transparent isolation cavity 7 is set between the support rod 502 and the burner 4, the above-mentioned transparent isolation cavity 7 can also play a role in blocking the flame, preventing the support rod 502 from directly contacting the flame generated by the burner 4 for a long time, protecting the experimental device, and extending the service life of the support rod.

[0029] In another preferred embodiment of the present invention, it also includes a heat spreader 8 horizontally fixed between two support rods 502, the lower end surface of the heat spreader 8 is against the edge of the upper port of the transparent isolation chamber 7, and the heat spreader 8 can suppress the jet-like flame generated by the burner 4. The flame reaches the position of the battery clamp 503 (i.e., it contacts the lithium battery) after being dispersed by the heat spreader 8, and uniformly heats the lithium battery until the lithium battery explodes. At the same time, the heat spreader 8 divides the transparent combustion chamber 6 into two parts, the lower part can observe the original jet-like flame generated by the burner 4, and the upper part can observe the deflagration flame generated by the lithium battery. In this solution, the above-mentioned transparent isolation chamber 7 can also axially support the heat spreader 8.

[0030] In one example, the above-mentioned heat spreader 8 is a honeycomb ceramic structure, which is in the shape of a round cake as a whole. The outer edge of the heat spreader 8 transitionally matches the inner wall of the transparent combustion chamber 6, and the flame generated by the forced burner 4 can only reach the battery cell fixture 503 after being dispersed by the heat spreader 8.

[0031] Based on the technical solution that the transparent isolation cavity 7 can also axially support the heat spreader 8, in a more optimal detailed solution, the above-mentioned transparent isolation cavity 7 should exceed the nozzle end of the burner 4 in the vertical direction to reserve a certain observation space for the flame ejected from the burner 4. Therefore, the height of the upper port of the transparent isolation cavity 7 is at least 10 mm greater than the height of the nozzle end of the burner 4.

[0032] From the description in the above implementation scheme, it can be known that the above-mentioned transparent isolation cavity 7, battery cell fixing unit 5 and transparent combustion chamber 6 are structures that are coaxially sleeved from the inside to the outside, and their radial fixation can be various, such as being directly threadedly connected to the inner bottom of the isolation cavity 1. In one example, a fixing plate 9 is laid on the inner bottom of the isolation cavity 1, and a through hole for avoiding the burner is arranged in the center of the fixing plate 9. After the through hole is expanded outward, it cooperates with the inner bottom of the isolation cavity 1 to form a step, and the step is used to accommodate the transparent isolation cavity 7, the annular base 501 and the transparent combustion chamber 6 that are coaxially sleeved from the inside to the outside. In this scheme, the setting of the fixing plate 9 limits the radial movement of the transparent isolation cavity 7, the annular base 501 and the transparent combustion chamber 6, but does not limit the vertical upward movement of the three, so the transparent isolation cavity 7, the battery cell fixing unit 5 and the transparent combustion chamber 6 can be pulled out upward for disassembly.

[0033] In this embodiment, the cover body 2 is detachably mounted on the top of the isolation chamber 1 , such as by a threaded connection or a snap-on connection, so that the experimenter can quickly disassemble the cover body 2 after the experiment and remove the lithium battery remains from the isolation chamber 1 .

[0034] The observation window 3 mentioned above can be any transparent window arranged radially along the isolation cavity 1. In one example, the observation window 3 includes a mounting seat protruding radially along the isolation cavity 1, and a transparent plate fixed on the inner edge of the mounting seat.

[0035] In the above embodiment, the transparent combustion chamber 6, the observation window 3 and the transparent isolation chamber 7 are components that need to have a light-transmitting function. They need to be transparent, resistant to high temperatures, and have a certain strength. Therefore, transparent quartz material can be selected to make them.

[0036] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A lithium-ion battery fire and deflagration test device, comprising an isolation cavity and a cover installed on the top of the isolation cavity, characterized in that: The outer wall of the isolation cavity is evenly provided with pairs of observation windows along its circumference. A burner is installed at the bottom of the isolation cavity, and the nozzle end of the burner is arranged upward. The input end of the burner is provided with a fuel input pipe and an oxygen input pipe with adjustable flow. A battery cell fixing unit is arranged above the burner. The burner and the battery cell fixing unit are wrapped in a cylindrical transparent combustion chamber, and the upper end of the transparent combustion chamber vertically passes through the surface of the cover body.

2. The lithium-ion battery fire and deflagration test device according to claim 1, characterized in that: It also includes a cylindrical transparent isolation chamber, which is coaxially sleeved on the outer side of the nozzle end of the burner.

3. The lithium-ion battery fire and deflagration test device according to claim 2, characterized in that: The battery cell fixing unit includes a circular ring base, a support rod mirror-imaged on the upper end surface of the circular ring base, and a battery cell clamp fixed on the upper ends of the two support rods, wherein the circular ring base is coaxially sleeved on the outer side of the transparent isolation cavity.

4. The lithium-ion battery fire and deflagration test device according to claim 3, characterized in that: It also includes a heat spreader fixed horizontally between the two support rods, and the lower end surface of the heat spreader is against the edge of the upper port of the transparent isolation cavity.

5. The lithium-ion battery fire and deflagration testing device according to claim 4, characterized in that: The heat sink is a honeycomb ceramic structure.

6. The lithium-ion battery fire and deflagration testing device according to claim 4, characterized in that: The outer edge of the heat diffusion plate is transitionally matched with the inner wall of the transparent combustion chamber.

7. The lithium-ion battery fire and deflagration testing device according to claim 4, characterized in that: The height of the upper port of the transparent isolation cavity is at least 10 mm greater than the height of the nozzle end of the burner.

8. The lithium-ion battery fire and deflagration testing device according to claim 3, characterized in that: The inner bottom of the isolation cavity is paved with a fixed plate, and a through hole for avoiding the burner is arranged at the center of the fixed plate. The through hole is expanded outward to cooperate with the inner bottom of the isolation cavity to form a step, and the step is used to accommodate the transparent isolation cavity, the annular base and the transparent combustion chamber which are coaxially sleeved in sequence from the inside to the outside.

9. The lithium-ion battery fire and deflagration testing device according to claim 1, characterized in that: The cover body is detachably mounted on the top of the isolation cavity.

10. The lithium-ion battery fire and deflagration testing device according to claim 1, characterized in that: The observation window comprises a mounting seat protruding radially along the isolation cavity, and a transparent plate fixed on the inner edge of the mounting seat.

Images