Test method for inhibiting thermal runaway of lithium ion battery by hydrogel for packaging box

Abstract

The invention relates to a test method for inhibiting thermal runaway of a lithium ion battery by hydrogel for a packaging box, which comprises the following steps: preparing a fire extinguishing agent, cooling a filter hole at the bottom of a fire extinguishing agent containing mold by using high-temperature paraffin until the filter hole is sealed, and pouring the hydrogel into a containing cavity on the fire extinguishing agent containing mold; preparing a lithium ion battery, fully charging the lithium ion battery, and then putting the lithium ion battery at the bottom in a packaging box; the first thermocouple monitors the temperature of the heating plate, the second thermocouple monitors the temperature of the lithium ion battery, the third thermocouple monitors the temperature above the lithium ion battery, and the camera monitors and records the whole test process; a fire extinguishing agent containing mold containing hydrogel is placed on the top of the packaging box, and a heating plate is started; the heating plate is started to heat the lithium ion battery; and the lithium ion battery is subjected to thermal runaway fire, temperature and video in the test process are recorded, and data processing and data analysis are carried out. The testing method has the advantages of simplicity and convenience in operation, low cost and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal runaway, and specifically to a test method for inhibiting the thermal runaway of lithium-ion batteries with hydrogel in a packaging box. Background Art

[0002] If lithium-ion batteries encounter working conditions such as long-term vibration, impact, high temperature, and low air pressure during transportation, they are prone to trigger thermal runaway and catch fire. Therefore, packaging boxes with fire extinguishing functions are the trend for the transportation safety of lithium batteries. Currently, the common method for verifying the fire extinguishing performance of lithium-ion battery fire extinguishing agents is to release the fire extinguishing agent through a high-pressure water pump or high-pressure gas, which is not applicable to the scenario of lithium battery transportation packaging and lacks the performance test of fire extinguishing agents for lithium battery transportation packaging. The present invention has developed a method for releasing the fire extinguishing agent by gravity to verify the fire extinguishing performance of water-based fire extinguishing agents, and relates to a test method for inhibiting the thermal runaway of lithium-ion batteries with water or hydrogel fire extinguishing agents. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the main purpose of the present invention is to provide a test method for inhibiting the thermal runaway of lithium-ion batteries with hydrogel in a packaging box.

[0004] The technical solution of the present invention is as follows:

[0005] A test method for inhibiting the thermal runaway of lithium-ion batteries with hydrogel in a packaging box, the test method comprising the following steps:

[0006] S1: Prepare the fire extinguishing agent, seal the filter holes at the bottom of the fire extinguishing agent storage mold with high-temperature paraffin, weigh 200 g of hydrogel, and pour the weighed hydrogel into the accommodation cavity on the fire extinguishing agent storage mold;

[0007] S2: Prepare the lithium-ion battery, fully charge the lithium-ion battery, and then place the fully charged lithium-ion battery at the bottom inside the packaging box;

[0008] S3: Arrange temperature sensors: fixedly install a heating plate at the bottom inside the packaging box, place the fully charged lithium-ion battery on the heating plate, set a first thermocouple on the upper surface of the heating plate to monitor the temperature of the heating plate through the first thermocouple, set a second thermocouple on the upper surface of the lithium-ion battery to monitor the temperature of the upper surface of the lithium-ion battery through the second thermocouple; at the same time, set a third thermocouple at a position 5 cm above the upper surface of the lithium-ion battery on the inner side wall of the packaging box to monitor the temperature at a position 5 cm above the lithium-ion battery through the third thermocouple; install a camera on the top side wall inside the packaging box to monitor and record the test process through the camera;

[0009] S4: Arranging the fire extinguishing agent: Place the fire extinguishing agent containing mold filled with hydrogel on the top of the packing box. At the same time, set a first opening on the top of the packing box. The bottom of the fire extinguishing agent containing mold is placed in the first opening, and the bottom of the fire extinguishing agent containing mold is located directly above the lithium-ion battery;

[0010] S5: Turning on the heating plate: Start the heating plate to heat the lithium-ion battery placed on it;

[0011] S6: The lithium-ion battery has a thermal runaway and catches fire. The first thermocouple detects the temperature of the lower surface of the heating plate, the second thermocouple monitors the temperature of the upper surface of the lithium-ion battery, and the third thermocouple monitors the temperature at a position 5 cm above the lithium-ion battery. At the same time, the camera monitors and records the entire test process;

[0012] S7: Data processing and data analysis.

[0013] An electric heating device is provided outside the packing box. The electric heating device is electrically connected to the heating plate, and the heating plate is heated by the electric heating device.

[0014] A temperature recorder is also provided outside the packing box. The temperature recorder is electrically connected to the first thermocouple, the second thermocouple, and the third thermocouple respectively.

[0015] The fire extinguishing agent containing mold includes a front side plate, a rear side plate, a left side plate, a right side plate, and a bottom plate. Among them: the front end of the left side plate is fixedly arranged at the left end of the front side plate, and the rear end of the left side plate is fixedly arranged at the left end of the rear side plate; the front end of the right side plate is fixedly arranged at the right end of the front side plate, and the rear end of the right side plate is fixedly arranged at the right end of the rear side plate; the left end of the bottom plate is fixedly arranged at the bottom end of the left side plate, the front end of the bottom plate is fixedly arranged at the bottom end of the front side plate, the right end of the bottom plate is fixedly arranged at the bottom end of the right side plate, and the rear end of the bottom plate is fixedly arranged at the bottom end of the rear side plate.

[0016] The front side plate, the rear side plate, the left side plate, the right side plate, and the bottom plate form the accommodating cavity, and a plurality of the filtering holes are uniformly arranged on the bottom plate.

[0017] The upper end length of the front side plate is greater than the lower end length of the front side plate, and the upper end length of the rear side plate is greater than the lower end length of the rear side plate.

[0018] The upper end length of the left side plate is greater than the lower end length of the left side plate, and the upper end length of the right side plate is greater than the lower end length of the right side plate.

[0019] The upper end length of the left side plate is greater than the width of the packing box, and the lower end length of the left side plate is less than the width of the packing box.

[0020] The upper end length of the right side plate is greater than the width of the packing box, and the lower end length of the right side plate is less than the width of the packing box.

[0021] The present invention has the following advantages and beneficial effects: The present invention relates to a test method for inhibiting thermal runaway of lithium-ion batteries with hydrogel in a packing box. The test method includes the following steps: Prepare a fire extinguishing agent, cool the filter holes at the bottom of the fire extinguishing agent storage mold with high-temperature paraffin until they are sealed, and pour the hydrogel into the accommodating cavity on the fire extinguishing agent storage mold; Prepare a lithium-ion battery, fully charge the lithium-ion battery, and then place the lithium-ion battery at the bottom inside the packing box; Arrange temperature sensors, the first thermocouple monitors the temperature of the heating plate, the second thermocouple monitors the temperature of the lithium-ion battery, the third thermocouple monitors the temperature above the lithium-ion battery, and the camera monitors and records the entire test process; Arrange the fire extinguishing agent: Place the fire extinguishing agent storage mold filled with hydrogel on the top of the packing box, turn on the heating plate: Start the heating plate to heat the lithium-ion battery; The lithium-ion battery undergoes thermal runaway and catches fire, record the temperature and video during the experiment, data processing and data analysis; The test method of the present invention has the advantages of simple operation and low cost. Description of the Drawings

[0022] Figure 1 It is a schematic three-dimensional structure diagram of the cooperation between the packing box and the fire extinguishing agent storage mold provided by the embodiment of the present invention.

[0023] Figure 2 It is a schematic top view structure diagram of the fire extinguishing agent storage mold provided by the embodiment of the present invention.

[0024] Figure 3 It is a schematic three-dimensional structure diagram of the fire extinguishing agent storage mold provided by the embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of the temperature change during the experimental test of the combustion thermal runaway of the lithium-ion battery provided by the embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of the temperature change when methyl cellulose gel is filled as the fire extinguishing agent in the fire extinguishing agent storage mold during the experimental test of the combustion thermal runaway of the lithium-ion battery provided by the embodiment of the present invention.

[0027] Figure 6 It is a schematic diagram of the temperature change when hydroxyethyl cellulose gel is filled as the fire extinguishing agent in the fire extinguishing agent storage mold during the experimental test of the combustion thermal runaway of the lithium-ion battery provided by the embodiment of the present invention.

[0028] Figure 7 It is a schematic diagram of the temperature change when pure water is filled as the fire extinguishing agent in the fire extinguishing agent storage mold during the experimental test of the combustion thermal runaway of the lithium-ion battery provided by the embodiment of the present invention.

[0029] Figure 8 It is a schematic flowchart of a test method for suppressing thermal runaway of lithium-ion batteries by using hydrogel for packaging boxes provided by an embodiment of the present invention. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0034] As Figures 1 to 8 shown: A test method for suppressing thermal runaway of lithium-ion batteries by using hydrogel for packaging boxes provided by an embodiment of the present invention, the test method includes the following steps:

[0035] S1: Prepare the fire extinguishing agent. Cool the filter holes 101 at the bottom of the fire extinguishing agent storage mold 100 with high-temperature paraffin until they are sealed. Weigh 200 g of hydrogel and pour the weighed hydrogel into the accommodation cavity 102 on the fire extinguishing agent storage mold 100.

[0036] S2: Prepare a lithium-ion battery, fully charge the lithium-ion battery, and then place the fully charged lithium-ion battery at the bottom inside the packing box 200.

[0037] S3: Arrange temperature sensors: Fix a heating plate 201 at the bottom inside the packing box 200. Place the fully charged lithium-ion battery 202 on the heating plate 201. Set a first thermocouple 203 on the upper surface of the heating plate 201 to monitor the temperature of the heating plate 201 through the first thermocouple 203. Set a second thermocouple 204 on the upper surface of the lithium-ion battery 202 to monitor the temperature of the upper surface of the lithium-ion battery 202 through the second thermocouple 204. At the same time, set a third thermocouple 205 at a position 5 cm away from the upper surface of the lithium-ion battery 202 on the inner side wall of the packing box 200 to monitor the temperature at a position 5 cm above the lithium-ion battery through the third thermocouple 205. Set a camera 206 on the top side wall inside the packing box 200 to monitor and record the test process through the camera 206.

[0038] S4: Arrange the fire extinguishing agent: Place the fire extinguishing agent storage mold 100 containing hydrogel on the top of the packing box 200. At the same time, set a first opening on the top of the packing box 200. Place the bottom of the fire extinguishing agent storage mold 100 in the first opening, and the bottom of the fire extinguishing agent storage mold 100 is located directly above the lithium-ion battery 202.

[0039] S5: Turn on the heating plate: Start the heating plate 201 to heat the lithium-ion battery 202 placed on it.

[0040] S6: The lithium-ion battery 202 catches fire due to thermal runaway. The first thermocouple 203 monitors the temperature of the upper surface of the heating plate 201, the second thermocouple 204 monitors the temperature of the upper surface of the lithium-ion battery 202, and the third thermocouple 205 monitors the temperature at a position 5 cm above the lithium-ion battery 202. At the same time, the camera 206 monitors and records the entire test process.

[0041] S7: Data processing and data analysis.

[0042] An electric heating device is arranged outside the packing box 200. The electric heating device is electrically connected to the heating plate 201, and the heating plate 201 is heated through the electric heating device.

[0043] A temperature recorder is also provided on the exterior of the packaging box 200, and the temperature recorder is electrically connected to the first thermocouple 203, the second thermocouple 204, and the third thermocouple 205 respectively.

[0044] The fire extinguishing agent storage mold 100 includes a front side plate 111, a rear side plate 112, a left side plate 113, a right side plate 114, and a bottom plate 115, wherein:

[0045] The front end of the left side plate 113 is fixedly arranged at the left end of the front side plate 111, and the rear end of the left side plate 113 is fixedly arranged at the left end of the rear side plate 112; the front end of the right side plate 114 is fixedly arranged at the right end of the front side plate 111, and the rear end of the right side plate 114 is fixedly arranged at the right end of the rear side plate 112;

[0046] The left end of the bottom plate 115 is fixedly arranged at the bottom end of the left side plate 113, the front end of the bottom plate 115 is fixedly arranged at the bottom end of the front side plate 111, the right end of the bottom plate 115 is fixedly arranged at the bottom end of the right side plate 114, and the rear end of the bottom plate 115 is fixedly arranged at the bottom end of the rear side plate 112.

[0047] The front side plate 111, the rear side plate 112, the left side plate 113, the right side plate 114, and the bottom plate 115 form the accommodation cavity 102, and a plurality of the filter holes 101 are uniformly arranged on the bottom plate 115.

[0048] The length of the upper end of the front side plate 111 is greater than the length of the lower end of the front side plate 111, and the length of the upper end of the rear side plate 112 is greater than the length of the lower end of the rear side plate 112. Through the above design, that is, the shapes of the front side plate 111 and the rear side plate 112 are both inverted isosceles trapezoids. The length of the upper end of the left side plate 113 is greater than the length of the lower end of the left side plate 113, and the length of the upper end of the right side plate 114 is greater than the length of the lower end of the right side plate 114. At the same time, the shape of the bottom plate 115 is square. Through the above design, that is, the shapes of the left side plate 113 and the right side plate 114 are inverted isosceles trapezoids. Therefore, when the left side plate 113, the front side plate 111, the right side plate 114, and the rear side plate 112 are fixedly connected, an accommodation cavity 102 in the shape of an inverted frustum of a square pyramid is formed.

[0049] A test method for suppressing the thermal runaway of lithium-ion batteries by using hydrogel in a packaging box provided by an embodiment of the present invention is specifically referred to Table 1:

[0050] Table 1 Experimental key parameter results

[0051]

[0052]

[0053] The lithium-ion battery in the experiment in Table 1 above is an 8AH ternary lithium-ion battery. 200g of fire extinguishing agent is used, and the electric heating device is turned off when the lithium-ion battery thermally runs out of control. It can be seen from Table 1 above that:

[0054] 1. When the accommodating cavity 102 of the fire extinguishing agent holding mold 100 is not filled with fire extinguishing agent, that is, during blank combustion, the highest temperature after the lithium-ion battery burns and thermally runs out of control is 687.8 °C. The time required for the highest temperature of the lithium-ion battery to drop to 200 °C is 684 s, and the burning time of the lithium-ion battery is 38 s;

[0055] 2. When the fire extinguishing agent filled in the accommodating cavity 102 of the fire extinguishing agent holding mold 100 is methyl cellulose gel, the highest temperature after the lithium-ion battery burns and thermally runs out of control is 559.7 °C. The continuous release time of the fire extinguishing agent is 9 s, and at the same time, the time from the release of the fire extinguishing agent to the flame extinction of the lithium-ion battery is 26 s. In addition, the time required for the highest temperature of the lithium-ion battery to drop to 200 °C is 223 s, the short-term temperature drop rate is 8.7 °C / s, and the long-term temperature drop rate is 0.77 °C / s;

[0056] 3. When the fire extinguishing agent filled in the accommodating cavity 102 of the fire extinguishing agent holding mold 100 is hydroxy methyl cellulose gel, the highest temperature after the lithium-ion battery burns and thermally runs out of control is 552.5 °C. The continuous release time of the fire extinguishing agent is 8 s, and at the same time, the time from the release of the fire extinguishing agent to the flame extinction of the lithium-ion battery is 16 s. At the same time, the time required for the highest temperature of the lithium-ion battery to drop to 200 °C is 5 s, the short-term temperature drop rate is 26.7 °C / s, and the long-term temperature drop rate is 0.95 °C / s;

[0057] 4. When the fire extinguishing agent filled in the accommodating cavity 102 of the fire extinguishing agent holding mold 100 is pure water, the highest temperature after the lithium-ion battery burns and thermally runs out of control is 451.5 °C. The continuous release time of the fire extinguishing agent is 8 s, and at the same time, the time from the release of the fire extinguishing agent to the flame extinction of the lithium-ion battery is 5 s. In addition, the time required for the highest temperature of the lithium-ion battery to drop to 200 °C is 9 s, the short-term temperature drop rate is 6.33 °C / s, and the long-term temperature drop rate is 0.56 °C / s;

[0058] The following conclusions can be drawn from Table 1: In terms of short-term and long-term cooling performance, the hydrogel fire extinguishing agent far exceeds pure water. Among them, carboxymethyl cellulose hydrogel exhibits superior fire extinguishing and cooling capabilities. Its short-term cooling rate is approximately 4.2 times that of pure water and 3.1 times that of methyl cellulose hydrogel. Its long-term cooling rate is approximately 1.7 times that of pure water and 1.2 times that of methyl cellulose hydrogel. Although a flame retardant is added to the hydrogel fire extinguishing agent, its fluidity is low. Therefore, compared with pure water, its initial fire extinguishing ability is weak. In the absence of any fire extinguishing agent, the battery burned for 40 seconds, while pure water suppressed the flame within 5 seconds. The fire extinguishing time of carboxymethyl cellulose hydrogel is 17 seconds, and that of methyl cellulose hydrogel is 26 s.

[0059] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test method for suppressing thermal runaway of lithium-ion batteries using hydrogel in packaging boxes, characterized in that: The test method comprises the following steps: S1: prepare the fire extinguishing agent, cool the filter holes at the bottom of the fire extinguishing agent holding mold with high-temperature paraffin until they are sealed, weigh 200g of hydrogel, and pour the weighed hydrogel into the receiving cavity on the fire extinguishing agent holding mold; S2: prepare a lithium-ion battery, fully charge the lithium-ion battery, and then place the fully charged lithium-ion battery at the bottom of the packaging box; S3: Arrange temperature sensors: a heating plate is fixedly arranged at the bottom of the packaging box, a fully charged lithium-ion battery is placed on the heating plate, a first thermocouple is arranged on the upper surface of the heating plate, and a second thermocouple is arranged on the upper surface of the lithium-ion battery; a third thermocouple is arranged on the inner side wall of the packaging box at a position 5 cm away from the upper surface of the lithium-ion battery; a camera is arranged on the top side wall of the packaging box; S4: Arranging the fire extinguishing agent: placing the fire extinguishing agent containing mold containing the hydrogel on the top of the packaging box, and setting a first opening on the top of the packaging box, the bottom of the fire extinguishing agent containing mold is placed in the first opening, and the bottom of the fire extinguishing agent containing mold is located directly above the lithium-ion battery; S5: Turn on the heating plate: Turn on the heating plate to heat the lithium-ion battery placed thereon; S6: The lithium-ion battery has thermal runaway and catches fire. The temperature of the lower surface of the heating plate is detected by the first thermocouple, the temperature of the upper surface of the lithium-ion battery is monitored by the second thermocouple, the temperature of the position 5 cm above the lithium-ion battery is monitored by the third thermocouple, and the entire test process is monitored and recorded by the camera; S7: Data processing and data analysis.

2. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 1, characterized in that: An electric heating device is arranged outside the packaging box, and the electric heating device is electrically connected to the heating plate, so that the heating plate is heated by the electric heating device.

3. The test method for suppressing thermal runaway of lithium-ion batteries using hydrogel in packaging boxes according to claim 1, characterized in that: A temperature recorder is also arranged outside the packaging box, and the temperature recorder is electrically connected to the first thermocouple, the second thermocouple and the third thermocouple respectively.

4. A test method for suppressing thermal runaway of lithium-ion batteries using hydrogel in a packaging box according to any one of claims 1 to 3, characterized in that: The fire extinguishing agent containing mold comprises a front side plate, a rear side plate, a left side plate, a right side plate and a bottom plate, wherein: The front end of the left side panel is fixedly arranged at the left end of the front side panel, and the rear end of the left side panel is fixedly arranged at the left end of the rear side panel; the front end of the right side panel is fixedly arranged at the right end of the front side panel, and the rear end of the right side panel is fixedly arranged at the right end of the rear side panel; The left end of the bottom plate is fixedly arranged on the bottom end of the left side plate, the front end of the bottom plate is fixedly arranged on the bottom end of the front side plate, the right end of the bottom plate is fixedly arranged on the bottom end of the right side plate, and the rear end of the bottom plate is fixedly arranged on the bottom end of the rear side plate.

5. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 4, characterized in that: The front side plate, the rear side plate, the left side plate, the right side plate and the bottom plate form the accommodating cavity, and a plurality of the filtering holes are evenly arranged on the bottom plate.

6. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 4, characterized in that: The length of the upper end of the front side plate is greater than the length of the lower end of the front side plate, and the length of the upper end of the rear side plate is greater than the length of the lower end of the rear side plate.

7. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 4, characterized in that: The length of the upper end of the left side plate is greater than the length of the lower end of the left side plate, and the length of the upper end of the right side plate is greater than the length of the lower end of the right side plate.

8. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 7, characterized in that: The length of the upper end of the left side plate is greater than the width of the packaging box, and the length of the lower end of the left side plate is less than the width of the packaging box.

9. The method for testing a packaging box using hydrogel to inhibit thermal runaway of a lithium-ion battery according to claim 7, characterized in that: The length of the upper end of the right side plate is greater than the width of the packaging box, and the length of the lower end of the right side plate is less than the width of the packaging box.

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