Spontaneous combustion prevention fire-retardant battery

Abstract

The invention relates to the technical field of automobile battery fire prevention, and mainly discloses an anti-spontaneous combustion fire-retardant battery which comprises a battery shell, a plurality of battery packs are arranged in the battery shell, a plurality of pressure relief holes are further formed in the battery shell, and fire barriers are further arranged on the pressure relief holes; the flame arrester comprises a plurality of layers of barrier covers, a flame arresting disc is further arranged at the joint of the barrier covers and the pressure relief hole, and a flame arresting seam is formed in the flame arresting disc; wherein the barrier covers are provided with a plurality of flow-through hole layers in the flow measuring direction of the combustion medium, the flow-through hole layers in every two adjacent barrier covers are arranged in a staggered manner, and the flow-through hole layers and the fire-retardant seams are communicated with the inner space and the outer space of the battery shell, and the technology that after thermal failure of the battery, safe pressure relief can be achieved, and flames can be prevented from spreading outwards can be achieved.

Description

Technical Field

[0001] This invention relates to the technical field of fire prevention for automotive batteries, and in particular to a fire-retardant battery that prevents spontaneous combustion. Background Technology

[0002] In the field of new energy vehicles, batteries are a core component, and their safety is of paramount importance. In recent years, the number of new energy vehicles on the road has grown rapidly; however, battery fires have occurred frequently, drawing widespread attention.

[0003] Battery fires can be caused by a variety of factors, with thermal runaway being a key one. Internal short circuits, overcharging and over-discharging, high temperatures, and mechanical damage can all trigger thermal runaway, causing a rapid rise in battery temperature and ultimately, ignition. For example, during charging, the high heat generated by fast charging and the resulting uneven heating, or the increased internal pressure due to overcharging, can easily lead to thermal runaway. Vehicle collisions, chassis damage causing internal short circuits, battery management system (BMS) malfunctions that fail to detect abnormalities in time, cell quality defects, aging circuits, unauthorized modifications, and the presence of flammable or explosive materials inside the vehicle all significantly increase the risk of fire.

[0004] While current technologies for fire prevention and control include battery thermal management, BMS optimization, application of fire-resistant materials, and fire suppression system design, shortcomings remain. Existing explosion-proof valves, although capable of releasing pressure when the battery's internal pressure is excessively high, lack flame-retardant functionality. When thermal runaway occurs in the battery, generating high-temperature flames and flammable gases, the explosion-proof valve cannot effectively prevent the flames from spreading, causing the fire to spread further and exacerbating the combustion risk of the battery system and even the entire vehicle. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the existing explosion-proof valve for new energy vehicle batteries does not have a flame-retardant function.

[0006] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a self-ignition-resistant flame-retardant battery, which includes a battery casing, a plurality of battery packs are disposed inside the battery casing, a plurality of pressure relief holes are also provided on the battery casing, and a flame arrester is also provided on the pressure relief holes; the flame arrester includes a plurality of barrier covers, and a flame-arresting plate is provided at the connection between the barrier cover and the pressure relief hole, and a flame-arresting slit is provided in the flame-arresting plate; wherein, the barrier cover has a plurality of flow-through hole layers in the flow direction of the combustion medium, the flow-through hole layers on two adjacent barrier covers are staggered, and the flow-through hole layers and the flame-arresting slit communicate with the inner and outer spaces of the battery casing.

[0007] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the barrier cover is provided with two layers, including a first barrier cover and a second barrier cover, the perforated layer on the first barrier cover is the first perforated layer, and the perforated layer on the second barrier cover is the second perforated layer; the first perforated layer and the second perforated layer are staggered along the axial direction of the flame arrester.

[0008] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the second shield includes a first shielding ring and a first impact plate that is sealed and connected to its top opening, the top surface of the first impact plate being directly injected with a combustion medium and high-pressure gas.

[0009] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the first impact plate is a sealed structure.

[0010] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the first impact plate has a coaxial array of several sets of impact perforations.

[0011] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the second flow-through layer is opened at the same height on the wall of the first blocking ring cover, and each layer of the second flow-through layer contains a plurality of sets of first flow-through holes, which are circumferentially distributed; the hole axes of two first flow-through holes in the same layer intersect on the axis of the first blocking ring cover.

[0012] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the first shield includes a second shield ring shield, the first flow-through layer is opened at the same height on the shield wall of the second shield ring shield, each first flow-through layer contains a plurality of sets of second flow-through holes, and the radial projections of the first flow-through holes and the second flow-through holes do not intersect.

[0013] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the diameter of the first flow-through hole gradually decreases from the uppermost second flow-through layer to the lowermost second flow-through layer, and the diameter of the second flow-through hole gradually increases from the uppermost first flow-through layer to the lowermost first flow-through layer.

[0014] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the first shield further includes a second impact plate sealed and connected to the top opening of the second shield ring cover, the first impact plate and the second impact plate are parallel and form a horizontal flow gap between them, the height of the horizontal flow gap being H; the second shield ring cover is coaxially disposed inside the first shield ring cover, forming a longitudinal flow gap between them, the longitudinal flow gap communicating with the horizontal flow gap and together forming a through flow gap; the difference between the outer radius of the second shield ring cover and the inner radius of the first shield ring cover is R, and H is greater than R.

[0015] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the second flow holes are circumferentially distributed; the axes of the two second flow holes in the same layer intersect on the axis of the second blocking ring cover.

[0016] In a preferred embodiment of the fire-retardant battery for preventing spontaneous combustion of the present invention: the distance between the walls of the first flow-through holes in two adjacent layers is M; the diameter of the second flow-through hole is T1, the diameter of the first flow-through hole is T2, T1 is less than T2, and T1 is equal to M; the axis of the second flow-through hole is located on the bisector of the angle formed by the axes of the two adjacent sets of the first flow-through holes.

[0017] In a preferred embodiment of the self-ignition-resistant fire-retardant battery of the present invention: the fire-retardant plate includes a plate shell, a plate core, a smooth annular steel strip and a triangular corrugated steel strip, and a perforation is provided in the center of the plate core; the smooth annular steel strip and the triangular corrugated steel strip are spirally and alternately fixedly connected between the plate shell and the plate core.

[0018] In a preferred embodiment of the fire-retardant battery described in this invention: several sets of independent fire-retardant seams are formed between the smooth annular steel strip and the triangular corrugated steel strip, the radial cross-sectional shape of the fire-retardant seam is triangular, and the included angle between the axis of the fire-retardant seam and the axis of the disk core is 20°±5°.

[0019] In a preferred embodiment of the fire-retardant battery described in this invention, the vertical distance from the vertex of the triangular fire-retardant seam to the base tangent to the smooth annular steel strip is 0.5 mm.

[0020] In a preferred embodiment of the fire-retardant battery described in this invention: an explosion-proof valve body is fixedly connected to the pressure relief hole located outside the battery casing. The explosion-proof valve body includes a valve seat, a valve disc, and a valve core. The valve seat is located outside the battery casing, the valve core is fixedly located in the middle of the valve seat, and the valve disc is movably located at the bottom of the valve seat, and the valve disc and the valve core are elastically connected. The valve core is inserted into the middle of the fire-retardant disc.

[0021] The beneficial effects of this invention are as follows:

[0022] This invention, through a combination of axial blocking of direct injection of the combustion medium and radial pressure relief channel, can greatly reduce the possibility of flames being ejected from the battery pack in an explosive or burning state. Furthermore, the inclined fire-arresting slits inside the fire-arresting plate increase the movement path of the combustion medium and improve the turbulence intensity of the medium, thereby further enhancing the fire extinguishing effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein:

[0024] Figure 1 The internal structure diagram of the fire-retardant battery is shown.

[0025] Figure 2 The working principle diagram of the fire-retardant battery is shown;

[0026] Figure 3 This image shows a view of a fire-retardant battery designed to prevent spontaneous combustion.

[0027] Figure 4 A cross-sectional view of the explosion-proof valve body of the self-ignition-resistant flame-retardant battery is shown.

[0028] Figure 5 An exploded view showing the connection between the flame-arresting base, barrier cover, and flame-arresting plate of the self-ignition-resistant flame-arresting battery is shown.

[0029] Figure 6 A structural diagram of the barrier cover for a self-ignition-resistant fire-retardant battery is shown.

[0030] Figure 7 A cross-sectional view of the barrier cover of the fire-retardant battery is shown;

[0031] Figure 8 A diagram showing the axial arrangement of the first and second flow-through holes in a self-ignition-resistant fire-retardant battery is provided.

[0032] Figure 9 A radial distribution diagram of the first and second flow-through holes of the fire-retardant battery is shown.

[0033] Figure 10 The diagram shows the structure of the flame arrestor plate in a self-ignition-preventing flame-retardant battery.

[0034] Figure 11 A detailed diagram of the flame-retardant seam of the self-ignition-preventing flame-retardant battery is shown.

[0035] Figure 12 A diagram showing the inclination angle of the flame-retardant seam in a self-ignition-preventing flame-retardant battery is provided.

[0036] Figure 13 The diagram shows the relationship between the inclination angle of the flame-retardant seam and the internal contact area of ​​the fire-retardant battery.

[0037] Figure 14 The diagram shows the internal turbulence intensity of the flame-retardant joint of the self-ignition-preventing flame-retardant battery at different inclination angles;

[0038] Figure 15The diagram shows the internal flow rate variation of the flame-retardant slit of the self-ignition-preventing flame-retardant battery under different inclination angles;

[0039] Figure 16 A schematic diagram illustrating the simulation conditions of the internal and external pressure difference of the battery pack is shown.

[0040] Figure 17 The diagram shows different tilt angles of the flame-retardant seam in the self-ignition-preventing flame-retardant battery. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0042] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0043] Reference Figures 1 to 17 This embodiment provides a self-ignition resistant battery pack, which includes a battery housing 100, a plurality of battery packs C are arrayed inside the battery housing 100, and a plurality of pressure relief holes S are opened in the middle of the battery housing 100.

[0044] Specifically, in this embodiment, the position of the pressure relief hole S on the fire-retardant battery can be adjusted according to the actual usage scenario, and it only needs to be roughly located in the middle of the battery pack.

[0045] It also includes a flame arrester 200, which includes several layers of barrier covers 201 and a base 202. The base 202 is disposed on the pressure relief hole S inside the battery housing 100, and the barrier covers 201 are disposed in the direct injection and crossflow directions of the combustion medium of the battery pack.

[0046] The barrier cover 201 is fixedly mounted on the base 202. The barrier cover 201 includes at least two layers and has a barrel-shaped structure. It can be stacked in three, four or more layers. Preferably, this embodiment includes two layers of barrier cover 201, that is, the barrier cover 201 includes a first barrier cover 201a and a second barrier cover 201b. The second barrier cover 201b blocks the first barrier cover 201a from the initial contact with the combustion medium.

[0047] Furthermore, the barrier cover 201 has several layers of flow-through holes L, the flow-through hole layer L on the first barrier cover 201a is the first flow-through layer L1, and the flow-through hole layer L on the second barrier cover 201b is the second flow-through layer L2.

[0048] Specifically, under extreme conditions, a set of batteries is installed at the top of the barrier cover 201. When the battery is damaged and burns, the combustion medium inside it will spray directly towards the barrier cover 201 below. At this time, the barrier cover 201 will vertically block it from spraying directly out of the battery pack casing, thus preventing it from igniting other components.

[0049] The flame arrestor plate 300 is located inside the base 202. A flame arrestor slit F is opened inside the flame arrestor plate 300. The combustion medium and high-pressure gas pass through the second flow layer L2, the first flow layer L1 and the flame arrestor slit F in sequence. An explosion-proof valve body 400 is movably installed at the bottom of the flame arrestor plate 300.

[0050] The explosion-proof valve body 400 includes a valve seat 401, a valve disc 402 and a valve core 403. The valve seat 401 is located outside the battery housing 100, the valve core 403 is fixedly located in the middle of the valve seat 401, and the valve disc 402 is movably located at the bottom of the valve seat 401, and the valve disc 402 and the valve core 403 are elastically connected.

[0051] The valve core 403 is slidably inserted into the middle of the flame arrestor plate 300. During use, the high-pressure gas passing through the flame arrestor gap F pushes the valve plate 402 downward, and at this time, a pressure relief gap is formed between the valve plate 402 and the valve seat 401.

[0052] The second shield 201b includes a first shield ring shield 201b-1 and a first impact plate 201b-2 that is sealed and fixedly connected to its top opening. The top surface of the first impact plate 201b-2 is directly injected with the combustion medium and high-pressure gas.

[0053] In this embodiment, the first impact plate 201b-2 can have the following two structures:

[0054] The first type has a sealing structure in which the first impact plate 201b-2 completely blocks the first shield 201a from the combustion medium in the axial direction.

[0055] Alternatively, the first impact plate 201b-2 may have several sets of impact perforations K1 arranged in a coaxial array. In this case, when the combustion medium is directly injected, a portion of it will pass through the impact perforations K1 and collide with the first shield 201a below.

[0056] The second flow-through layer L2 is opened at the same height on the wall of the first blocking ring cover 201b-1. The two adjacent second flow-through layers L2 are arranged in parallel. Each second flow-through layer L2 contains several sets of first flow-through holes 201b-1a, and the first flow-through holes 201b-1a are circumferentially distributed.

[0057] The axes of the two first flow through holes 201b-1a in the same layer intersect on the axis of the first blocking ring cover 201b-1.

[0058] The first shield 201a includes a second shield ring 201a-1 and a second impact plate 201a-2 that is sealed and fixedly connected to its top opening. The second impact plate 201a-2 can only be a sealed structure. The first impact plate 201b-2 is parallel to the second impact plate 201a-2, and a flow gap A1 is formed between them. The height of the flow gap A1 is H.

[0059] Specifically, the second baffle shroud 201a-1 is coaxially disposed inside the first baffle shroud 201b-1, forming a longitudinal flow gap A2 between them. The longitudinal flow gap A2 is connected to the horizontal flow gap A1, and together they form the through flow gap A. The difference between the outer radius of the second baffle shroud 201a-1 and the inner radius of the first baffle shroud 201b-1 is R, and H is greater than R.

[0060] In this case, the high-pressure gas and combustion medium that enter the longitudinal flow gap A2 through the first flow through hole 201b-1a can more easily flow into the horizontal flow gap A1. The high-pressure gas and combustion medium around the gap converge and interact with each other in the horizontal flow gap A1, which can stabilize the flow rate of the combustion mixture.

[0061] Furthermore, the first flow-through layer L1 is opened at the same height on the wall of the second baffle ring 201a-1. Each first flow-through layer L1 contains several sets of second flow-through holes 201a-1, which are distributed circumferentially.

[0062] The axes of the two second flow-through holes 201a-1 in the same layer intersect on the axis of the second baffle ring cover 201a-1. The second flow-through layer L2 and the first flow-through layer L1 are alternately arranged.

[0063] As an optional embodiment, the diameter of the first flow-through hole 201b-1a gradually decreases from the uppermost second flow-through layer L2 to the lowermost second flow-through layer L2, while the diameter of the second flow-through hole 201a-1 gradually increases from the uppermost first flow-through layer L1 to the lowermost first flow-through layer L1.

[0064] After a battery explodes, the solid and liquid particles generated generally splash in one direction and are easily blocked. However, due to the opening of the first flow-through hole 201b-1a and the second flow-through hole 201a-1, the total gas flow area is not reduced, and the impact on gas flow resistance is not too great. This ensures that after the explosion, the gas passes through the second shield 201b and the first shield 201a and overflows smoothly from the pressure relief valve below. This method of opening the aperture effectively prevents solid and liquid particles from passing through the explosion-proof mesh and entering the flame arrestor plate, which would cause the flame arrestor plate gaps to become blocked.

[0065] As an optional embodiment, the distance between the walls of the first flow through holes 201b-1a in two adjacent layers is M; the diameter of the second flow through hole 201a-1 is T1, the diameter of the first flow through hole 201b-1a is T2, T1 is less than T2, and T1 is equal to M.

[0066] It should be noted that in this embodiment, T1 is less than T2 and T1 equal to M is the preferred value. In specific use, it is only necessary to satisfy that the diameter of the first flow through hole 201b-1a is different from that of the second flow through hole 201a-1, and the second flow through hole 201a-1 and the first flow through hole 201b-1a are staggered, that is, the radial projections of the first flow through hole 201b-1a and the second flow through hole 201a-1 do not intersect.

[0067] Furthermore, in this embodiment, the diameter of the first flow-through hole 201b-1a located on the outer side can decrease in a stepwise manner from top to bottom, or it can change in an alternating manner.

[0068] Similarly, the diameter variation of the second flow-through hole 201a-1 located on the inner side can be the same as or opposite to that of the first flow-through hole 201b-1a, as long as the flow-through holes of the two layers do not intersect in the radial direction, so that the combustion medium will directly rush to the non-"hole" position of the inner layer after passing through the outer layer.

[0069] The axis of the second flow through hole 201a-1 is located on the bisector of the angle formed by the axes of the two adjacent sets of first flow through holes 201b-1a.

[0070] Specifically, the first flow through hole 201b-1a and the second flow through hole 201a-1 are completely offset from each other in the axial and radial directions. When the combustion mixture passes through the first flow through hole 201b-1a quickly, it does not pass directly through the second flow through hole 201a-1 and exit the battery pack, but instead impacts the wall of the second baffle shroud 201a-1, slowing down its flow rate.

[0071] The flame arrestor plate 300 includes a plate shell 301, a plate core 302, a smooth annular steel strip 303, and a triangular corrugated steel strip 304. A perforation K2 is provided in the center of the plate core 302. Specifically, the smooth annular steel strip 303 and the triangular corrugated steel strip 304 are spirally and alternately fixedly connected between the plate shell 301 and the plate core 302.

[0072] Several independent fire-resistant seams F are formed between the smooth annular steel strip 303 and the triangular corrugated steel strip 304. The radial cross-sectional shape of the fire-resistant seam F is triangular, and the angle between the axis of the fire-resistant seam F and the axis of the disc core 302 is 20°±5°.

[0073] Compared to a triangular cross-sectional shape, the radial cross-sectional shape of the fire-resistant seam F in this embodiment can also be a circle or a regular polygon.

[0074] When a circular fire-resistant joint F is used, the stress distribution of the circular cross-section of the fire-resistant joint F is uniform, without sharp edges, and it is highly compatible with circular pipes and easy to align during construction. However, the flame can easily penetrate along the diameter in a straight line, the fire-resistant path is short, and the filling material is prone to shrinkage or carbonization at high temperatures, which can lead to gaps and failure. In addition, the circular arc structure has a weak ability to reflect heat radiation and conducts heat quickly.

[0075] Polygonal cross-sections with straight sides are easy to cut and process, making them suitable for rectangular and square structures. They are easy to standardize and prefabricate, and have good initial sealing performance. However, at right-angle corners, stress concentration is severe at high temperatures, which can easily lead to cracking and the formation of fire channels. Flames can also penetrate along the diagonal shortcut, resulting in low fire-blocking efficiency. Furthermore, right-angle areas tend to accumulate heat, accelerating material aging.

[0076] The triangular cross section forces the flame to propagate in a zigzag pattern through multiple bends, with a path that is about 50% longer than that of a circle. The bends can refract and break the flame, reducing its propagation speed and resulting in the highest flame-blocking efficiency.

[0077] Furthermore, triangles are naturally stable structures that are not easily deformed or collapsed at high temperatures. The acute angles allow the fire-retardant material to self-wedge and fill densely when it expands. The angles can also reflect heat radiation, reduce heat transfer, and lower the temperature rise on the unexposed side.

[0078] Furthermore, refer to Figure 11 The vertical distance from the vertex of the fire-resistant seam F to the base tangent to the smooth annular steel strip 303 is 0.5mm.

[0079] Furthermore, in existing technologies, since the volume concentration of hydrogen gas generated by thermal failure is within the explosion limit range, according to the standard, GB5908 "Flame Arresters" IIC grade (0.2mm gap) should be selected. After testing, although IIC grade has a better flame arresting effect, because the battery explosion generates a large amount of solid waste (electrode materials, lithium fluoride / lithium carbonate, nickel / cobalt / manganese oxides, etc.), the 0.2mm gap in IIC grade is easily blocked by solids, and the pressure drop is very high. That is, at different angles, the smaller the gap value, the higher the pressure drop. The battery pack is ruptured, and the gas pressure cannot be released in time, which cannot meet the requirements of both safe pressure relief and flame arresting effect.

[0080] In this embodiment, by conducting fire-resistant experiments on fire-resistant seams F with different fire-resistant values ​​ranging from 0.2mm to 0.9mm, it was found that the fire-resistant effect of a 0.5mm triangular fire-resistant seam is the optimal size.

[0081] Specifically, based on the explosion group level and maximum safe test gap (MESG) of typical gases, simulated fire experiments of new energy batteries were conducted for flame-retardant gaps F with different resistance values ​​ranging from 0.2 mm to 0.9 mm. The average volume of the medium mainly generated by the thermal failure of the battery pack is shown in Table 1 below:

[0082] Table 1

[0083] medium Volume ratio (%) <![CDATA[CO2]]> 21.21 <![CDATA[CH2]]> 2.88 <![CDATA[C2H2]]> 0.29 <![CDATA[H2]]> 14.67 <![CDATA[O2]]> 23.83 <![CDATA[CH4]]> 4.89 other 32.23

[0084] According to Darcy's law, the pressure drop of a 0.2mm gap on a gas mixture is 16 times that of a 0.5mm gap, and the gas release rate is less than 1 / 4 of that of a 0.5mm gap. This results in the inability to release the pressure inside the battery pack in a timely manner. In 30 simulation experiments, the internal pressure of the battery pack suddenly increased from 0.3MPa to 2.1MPa in 27 of them, exceeding the pressure resistance limit of the aluminum casing by 1.8MPa. Therefore, it cannot simultaneously meet the requirements of safe pressure relief and flame arrest.

[0085] Furthermore, the quenching rates of the 0.3–0.4 mm flame arrestor seam for high-risk gases such as hydrogen and acetylene are 85% and 92%, respectively, but spark penetration still occurs, with the peak heat flow reaching 12 kW / m2, exceeding the safety threshold of 10 kW / m2.

[0086] Although the anti-clogging ability has been improved compared to the 0.2mm gap and the clogging rate has been reduced to 40%, it is still easily stuck by the sheet electrode material. Local current restriction occurred in 15% of the experiments, and the average pressure relief time was extended to 18 seconds, which exceeded the safety standard.

[0087] The 0.5mm triangular flame arrestor gap achieves a 100% quenching rate for hydrogen and acetylene through the angled turbulent quenching effect, with the heat flow stably controlled at 8.2kW / m2, a 28% reduction compared to the 0.2mm gap.

[0088] The flame needs to propagate along a 0.866mm zigzag path, and the actual flame-blocking path is 3.4 times longer than the 0.2mm straight path. In terms of gas venting, its throughput efficiency is 12 times higher than that of 0.2mm. In 10 simulated explosion experiments, the internal pressure of the battery pack dropped from 1.2MPa to 0.6MPa in only 8 seconds.

[0089] This size allows for a throughput of less than 3% for solid particles with a maximum diameter of 1mm, and the triangular acute-angle design utilizes airflow impact force to automatically expel some blockages, achieving an anti-clogging success rate of 97%. After a 1000℃ thermal cycling test, the gap width change rate is only ±0.03mm.

[0090] When the gap reaches 0.6–0.9 mm, the quenching rate of gases such as hydrogen and acetylene drops below 60%, and the heat flow exceeds 13 kW / m³. 2 A continuous jet of flame was observed.

[0091] The 0.9mm gap completely loses its flame-retardant function, and the high-temperature gas carrying sparks can be ejected up to 2.3 meters away, exceeding the "no flame spread" standard specified in GB38031.

[0092] Comprehensive experimental results show that the 0.5mm triangular flame-retardant seam, through geometric optimization and precise size matching, achieves efficient quenching of hazardous gases such as hydrogen while ensuring rapid pressure relief and anti-clogging performance. It outperforms other sizes in terms of overall performance in flame-retardant efficiency, pressure relief speed, and structural stability, making it the optimal choice for fire protection design of new energy battery packs.

[0093] Combined with reference Figure 13 and Figure 17 For flame arrester plates 300 of the same thickness and flame arrester gaps F of the same size, the larger the inclination angle of the flame arrester gap F, the stronger the flame arresting ability. There are two reasons for this. First, the inclined flame arrester gap will increase the contact area between the flame flow and the wall surface when the flame flows through the flame arrester plate 300, thereby increasing the cooling effect of the flame arrester plate 300 on the flame flow.

[0094] In summary, the 0.5mm triangular fire-resistant seam far surpasses other sizes in terms of fire-resistant efficiency, heat flow control, and structural stability. It can effectively resist fire and ensure safe pressure relief in the event of battery thermal runaway, making it the best choice for fire-resistant design of new energy batteries. Other widths are difficult to meet practical application requirements due to issues such as fire-resistant failure or structural risks.

[0095] Assuming the flame arrestor plate is 300mm thick and 1cm, and the flame arrestor joint F is triangular with a cross-sectional area of ​​0.196mm²,... 2 , which is the cross-sectional area when the vertical distance φ = 0.5 mm from the vertex of the fire-resistant joint F to the base tangent to the smooth annular steel strip 303.

[0096] Reference Figure 13 The contact area between the flame and the interior of the flame-arresting joint F was calculated for gap angles of 0°, 5°, 10°, 15°, 20°, 25°, and 30°. The wall area of ​​each flame-arresting joint F channel varies with the tilt angle as shown in Table 2 below:

[0097] Table 2

[0098]

[0099]

[0100] Combination Figure 14 Furthermore, the inclined flame arrestor seam F enhances the turbulence intensity of the fluid entering the seam. The greater the turbulence intensity, the shorter the extinguishing length of the flame after passing through the flame arrestor seam F, indicating that the flame arrestor plate 300 has a stronger flame arresting capability. The turbulence intensity inside the flame arrestor seam F was calculated at seam angles of 0°, 5°, 10°, 15°, 20°, 25°, and 30°, as shown in Table 3 below.

[0101] Table 3

[0102] angle Turbulence intensity (%) 0 80.46265181 5 80.88438436 10 82.4292137 15 85.4615441 20 90.27538376 25 96.2458703 30 104.1180988

[0103] Therefore, the larger the inclination angle of the fire-resistant joint F, the larger the wall area, the greater the turbulence intensity of the flow field, and thus the higher the fire-resistant efficiency.

[0104] Furthermore, increasing the inclination angle of the flame arrester F can sometimes lead to increased flow resistance. To assess the impact of the inclination angle on flow resistance, a 300mm section of the flow channel from the flame arrester plate was used for simulation calculations. The flow channel section was referenced... Figure 17 As shown.

[0105] Combination Figure 16 and Figure 17 Furthermore, assuming the internal gauge pressure of the battery pack is 5 kPa and the external pressure of the battery pack is the same as atmospheric pressure, i.e., the gauge pressure is 0 kPa, the volumetric flow rate that the flame arrestor plate 300 can pass through at gap angles of 0°, 5°, 10°, 15°, 20°, 25°, and 30° is calculated, as shown in Table 4 below:

[0106] Table 4

[0107]

[0108]

[0109] The calculation results show that, under the same internal and external pressure difference, for flame arrester plates of the same thickness, the larger the inclination angle of the flame arrester seam F, the smaller the flow rate. Furthermore, starting from an inclination angle of 20°, the slope of the flow rate curve decreases significantly as the inclination angle increases.

[0110] Considering the feasibility of the manufacturing process, it is advisable to select a flame-arresting seam F angle of 20° for the flame-arresting plate 300.

[0111] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A self-ignition-resistant fire-retardant battery, characterized in that: include, A battery housing (100) is provided inside the battery housing (100) and a number of battery packs (C) are provided inside the battery housing (100). A number of pressure relief holes (S) are also provided on the battery housing (100) and a flame arrester (200) is provided on the pressure relief holes (S). The flame arrester (200) includes several layers of barrier covers (201), and a flame arresting plate (300) is provided at the connection between the barrier cover (201) and the pressure relief hole (S), and a flame arresting slit (F) is provided in the flame arresting plate (300). The barrier cover (201) has several layers of perforated holes (L) in the crossflow direction of the combustion medium. The perforated holes (L) on two adjacent barrier covers (201) are staggered, and the perforated holes (L) are connected to the inner and outer spaces of the battery casing (100) through the flame arrestor seam (F).

2. The fire-retardant battery for preventing spontaneous combustion according to claim 1, characterized in that: An explosion-proof valve body (400) is fixedly connected to the pressure relief hole (S) located outside the battery housing (100). The explosion-proof valve body (400) includes a valve seat (401), a valve disc (402), and a valve core (403). The valve seat (401) is located outside the battery housing (100). The valve core (403) is fixedly located in the middle of the valve seat (401). The valve disc (402) is movably located at the bottom of the valve seat (401), and the valve disc (402) is elastically connected to the valve core (403). The valve core (403) is slidably inserted into the middle of the flame arrestor plate (300).

3. The fire-retardant battery for preventing spontaneous combustion according to claim 1 or 2, characterized in that: The barrier cover (201) is provided with two layers, including a first barrier cover (201a) and a second barrier cover (201b). The flow-through layer (L) on the first barrier cover (201a) is the first flow-through layer (L1), and the flow-through layer (L) on the second barrier cover (201b) is the second flow-through layer (L2). The second shield (201b) prevents the first shield (201a) from initial contact with the combustion medium, and the shield (201) is fixed to the battery casing (100) by the base (202); The first flow layer (L1) and the second flow layer (L2) are staggered along the axial direction of the flame arrester (200).

4. The fire-retardant battery against spontaneous combustion according to claim 3, characterized in that: The second shield (201b) includes a first shield ring shield (201b-1) and a first impact plate (201b-2) with a sealed connection to its top opening, the top surface of the first impact plate (201b-2) being directly injected with the combustion medium and high-pressure gas.

5. The fire-retardant battery against spontaneous combustion according to claim 4, characterized in that: The first impact plate (201b-2) is a sealed structure.

6. The fire-retardant battery for preventing spontaneous combustion according to claim 4, characterized in that: The first impact plate (201b-2) has several sets of impact perforations (K1) arranged in a coaxial array.

7. The fire-retardant battery for preventing spontaneous combustion according to claim 5 or 6, characterized in that: The second flow-through layer (L2) is opened at the same height on the wall of the first baffle ring cover (201b-1). Each second flow-through layer (L2) contains several sets of first flow-through holes (201b-1a), which are circumferentially distributed. The axes of the two first flow-through holes (201b-1a) on the same layer intersect on the axis of the first baffle ring cover (201b-1).

8. The fire-retardant battery against spontaneous combustion according to claim 7, characterized in that: The first shield (201a) includes a second shield ring shield (201a-1), and the first flow-through layer (L1) is formed at the same height on the shield wall of the second shield ring shield (201a-1). Each first flow-through layer (L1) contains a plurality of sets of second flow-through holes (201a-1a). The radial projections of the first flow through hole (201b-1a) and the second flow through hole (201a-1a) do not intersect.

9. The fire-retardant battery against spontaneous combustion according to claim 8, characterized in that: The diameter of the first flow-through hole (201b-1a) gradually decreases from the uppermost second flow-through layer (L2) to the lowermost second flow-through layer (L2), while the diameter of the second flow-through hole (201a-1a) gradually increases from the uppermost first flow-through layer (L1) to the lowermost first flow-through layer (L1).

10. The fire-retardant battery for preventing spontaneous combustion according to claim 8 or 9, characterized in that: The first shield (201a) further includes a second impact plate (201a-2) that is sealed and connected to the top opening of the second shield ring (201a-1). The first impact plate (201b-2) is parallel to the second impact plate (201a-2) and a flow gap (A1) is formed between them. The height of the flow gap (A1) is H. The second blocking ring cover (201a-1) is coaxially disposed inside the first blocking ring cover (201b-1), and a longitudinal flow gap (A2) is formed between the two. The longitudinal flow gap (A2) is connected to the horizontal flow gap (A1) and together they form a through flow gap (A). The difference between the outer radius of the second blocking ring cover (201a-1) and the inner radius of the first blocking ring cover (201b-1) is R, and H is greater than R.

11. The fire-retardant battery against spontaneous combustion according to claim 10, characterized in that: The second flow-through holes (201a-1a) are circumferentially distributed; The axes of the two second flow-through holes (201a-1a) in the same layer intersect on the axis of the second baffle ring (201a-1).

12. The fire-retardant battery against spontaneous combustion according to claim 11, characterized in that: The distance between the walls of the first flow through hole (201b-1a) in two adjacent layers is M; the diameter of the second flow through hole (201a-1a) is T1, the diameter of the first flow through hole (201b-1a) is T2, T1 is less than T2, and T1 is equal to M; The axis of the second flow through hole (201a-1a) is located on the bisector of the angle formed by the axes of the two adjacent sets of the first flow through holes (201b-1a).

13. The fire-retardant battery for preventing spontaneous combustion according to any one of claims 1 to 6, characterized in that: The fire arrestor plate (300) includes a plate shell (301), a plate core (302), a smooth annular steel strip (303) and a triangular corrugated steel strip (304), and the plate core (302) has a perforation (K2) in the middle. The smooth annular steel strip (303) and the triangular corrugated steel strip (304) are spirally and alternately fixedly connected between the disk shell (301) and the disk core (302).

14. The fire-retardant battery against spontaneous combustion according to claim 13, characterized in that: Several independent fire-resistant seams (F) are formed between the smooth annular steel strip (303) and the triangular corrugated steel strip (304). The radial cross-sectional shape of the fire-resistant seam (F) is triangular, and the angle between the axis of the fire-resistant seam (F) and the axis of the disc core (302) is 20°±5°.

15. The fire-retardant battery against spontaneous combustion according to claim 14, characterized in that: The vertical distance from the vertex of the triangular fire-resistant seam (F) to the base tangent to the smooth annular steel strip (303) is 0.5 mm.

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