A battery box and design method and control method

Abstract

This invention relates to the field of automotive technology, specifically to a battery housing and its design and control methods. It includes a lower housing end plate, a liquid cooling plate, a pressure equalizer, a limiting strip, a battery module, a lower housing side plate, a supporting cylinder, a pressure relief port, and a top cover. The lower housing end plate, lower housing side plate, and top cover constitute the housing body. The liquid cooling plate is integrated into the housing body. The battery module is fixed to the liquid cooling plate. The lower end of the supporting cylinder is fixed to the battery module. The pressure equalizer is located on the upper part of the supporting cylinder and can rotate around the center of the supporting cylinder. The pressure relief port is located on the battery module. A limiting strip is provided on the liquid cooling plate. This invention can equalize the internal pressure of the power battery and, in the event of thermal runaway, rapidly expel harmful gases through the pressure relief port, effectively delaying battery thermal runaway. This solves the problems of insufficient internal pressure equalization and slow pressure relief during thermal runaway in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, specifically to a battery housing, its design method, and its control method. Background Technology

[0002] As people's living standards continue to improve, cars have become an essential item for every family. However, with the increase in the number of gasoline-powered vehicles, the pollution of our living environment caused by harmful gases and other pollutants has reached a point that is unbearable. Therefore, we must find new energy sources that can replace gasoline to some extent in order to alleviate our environmental pressure.

[0003] Given this situation, new energy vehicles using power batteries have become increasingly popular due to their obvious advantages. First, new energy vehicles using power batteries are more cost-effective than gasoline vehicles; second, because batteries do not undergo oxidation reactions with oxygen, no excess exhaust gases are emitted during charging and discharging, effectively preventing environmental pollution.

[0004] As a key component of new energy vehicles, the structural safety and replacement speed of power batteries are extremely important. Current technology cannot achieve balanced internal pressure in power batteries, resulting in slow pressure release during thermal runaway. Summary of the Invention

[0005] This invention provides a battery housing, its design method, and its control method, which can equalize the internal air pressure of the power battery and, in the event of thermal runaway, rapidly expel harmful air pressure through the pressure relief port from the power battery, effectively delaying battery thermal runaway. This solves the problem in the prior art that the internal air pressure of the power battery cannot be equalized and that the air pressure relief speed is slow when the power battery experiences thermal runaway.

[0006] The technical solution of this invention is described below in conjunction with the accompanying drawings:

[0007] In a first aspect, embodiments of the present invention provide a battery housing, including a lower housing end plate 1, a liquid cooling plate 2, a pressure equalizer 3, a limiting strip 4, a battery module 5, a lower housing side plate 6, a supporting cylinder 7, a pressure relief port 8, and a top cover; the lower housing end plate 1, the lower housing side plate 6, and the top cover constitute the housing body; the liquid cooling plate 2 is integrated into the housing body; the battery module 5 is fixed on the liquid cooling plate 2; the lower end of the supporting cylinder 7 is fixed on the battery module 5; the pressure equalizer 3 is disposed on the upper part of the supporting cylinder 7 and can rotate around the center of the supporting cylinder 7; the pressure relief port 8 is disposed on the battery module 5; and the liquid cooling plate 2 is provided with a limiting strip 4.

[0008] Furthermore, the pressure equalizer 3 includes a radial plate 301, a middle plate 302, a flange plate 303, and a cutting plate 304; the middle plate 302 is disposed on the supporting cylinder 7 and can rotate around the supporting cylinder 7; a plurality of rotating blades are distributed around the circumference of the middle plate 302; each rotating blade includes a radial plate 301 and a flange plate 303; the upper surface of the flange plate 303 is the cutting plate 304.

[0009] Furthermore, the straight-line distance between the pressure relief port 8 and the pressure equalizer 3 is ≤0.2m.

[0010] Furthermore, the pressure equalizer 3 is a permanent magnet.

[0011] Furthermore, the supporting cylinder 7 contains an electromagnetic coil, which is powered by the low-voltage wiring harness of the battery assembly and forms an electromagnetic field after being energized; the electromagnetic coil receives signals from the battery management system and controls the rotation of the pressure equalizer 3 located at the upper end.

[0012] Secondly, embodiments of the present invention provide a battery assembly, including a battery housing.

[0013] Thirdly, embodiments of the present invention provide an electric vehicle, including a vehicle body and a battery assembly.

[0014] Fourthly, embodiments of the present invention provide a method for designing a battery housing, comprising:

[0015] The limiting rotation area V of the pressure balancer 3 is determined based on the battery thermal runaway delay safety factor HBS and the battery pressure equalization factor LHS:

[0016] The diameter D of the pressure balancer 3 and the thickness H of the intermediate plate (302) are determined based on the limit rotation area V of the pressure balancer 3.

[0017] Further, the limiting rotation area V of the pressure balancer 3 is defined as follows: V = HBS / CC*LHS / lnA*tanA(lnA*expA)*lnA*tanA(sinA*exp(A)*A*A*cot(A)*(2[lnA*tanA][9 / 5(A*sinC / A*C)][lnA*tanA][1 / 6(A / sinC C)], where CC is the battery structure threshold coefficient, taken as 0.53-0.62; A is the pressure rotation compensation parameter, taken as 9°>A>0°; and C is the pressure balance correction safety factor.

[0018] The diameter D is given by: D = V / (BN*E) / (BN*E)*0.55*lnA*tanA(lnA*tanAA*expA)*lnA*tanA(sinA*exp(A), where BN is the design height installation dimension; E is the battery arrangement dimension coefficient, which is taken as 1.23-1.53.

[0019] The thickness H=V*tan(A)*π[lnA*tanAA*tanA / lgC*expA*exp(A)]^2*lnA*tanA(A)*(3[lnA*tanA][1 / 5 (A*sinC / cosA*C)][lnA*tanA][1 / 6(A / sinC / tanC)]*lnA*sinA*expA*lnA*tanA(sinA*expA).

[0020] Fifthly, the present invention provides a method for controlling a battery housing, comprising the following steps:

[0021] Step 1: The battery management system collects the air pressure value of the battery pack through sensors inside the battery pack;

[0022] Step 2: The battery management system determines whether the battery box needs pressure equalization based on the collected air pressure signal. There are three modes: no working mode, normal mode, extreme mode, and thermal runaway mode.

[0023] Step 3: Define the highest air pressure received by the battery management system as SM, the lowest air pressure of the battery as SN, the air pressure difference SW = SM - SN, the safe air pressure threshold as SA, and the temperature difference as calculated from the test data every 100 milliseconds.

[0024] No-operation mode: SM≤SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW is ≤9*(1-lgC*expC*cosC*cos(2*C)lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, taken as 0.951<C<0.964; the battery management system is inactive, the supporting cylinder 7 is not working, and the pressure equalizer 3 does not rotate;

[0025] Normal mode: SA / (1-lgC*expC*cosC*cotC*lgC*expC)≥SM>SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW is ≤9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues a command to support cylinder 7 to work, and the pressure equalizer 3 rotates at 30% of its maximum speed, and feedback action is performed after 2 minutes;

[0026] Extreme mode: SM > SA / (1-lgC*expC*cosC*cotC*lgC*expC) or the curvature of SW > 9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues a command to support cylinder 7 to work, and the pressure equalizer 3 rotates at 90% of its maximum speed, and feedback action is performed after 3 minutes;

[0027] Thermal runaway mode: When the battery management system receives a battery thermal runaway alarm, it issues a command to support cylinder 7 to work and pressure equalizer 3 to rotate at 100% maximum speed until the system fails.

[0028] Step 4, Action Feedback: Provide signal feedback for the collected battery air pressure.

[0029] Signal judgment: SM≤SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW change≤9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, taken as 0.951<C<0.964; if the criteria are not met, repeat step three; otherwise, exit control.

[0030] The beneficial effects of this invention are as follows:

[0031] The electromagnetic field of the supporting cylinder of the present invention can control the rotation and stop of the pressure equalizer installed on the upper part. When the battery thermal runaway occurs, the pressure relief port will be burst by the pressure. The pressure equalizer can drive the harmful gas pressure to be quickly discharged from the battery power battery through the pressure relief port by rotating rapidly, effectively delaying the battery thermal runaway. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a portion of the structure of the present invention from one angle;

[0034] Figure 2 This is an enlarged schematic diagram of part of the structure of the present invention;

[0035] Figure 3 This is another schematic diagram of a portion of the structure of the present invention;

[0036] Figure 4 This is a schematic diagram of the air pressure equalizer in this invention from one angle;

[0037] Figure 5 This is another schematic diagram of the air pressure equalizer in this invention.

[0038] In the picture:

[0039] 1. Lower box end plate;

[0040] 2. Liquid cooling plate;

[0041] 3. Air pressure equalizer;

[0042] 301. Radial plate; 302. Intermediate plate; 303. Flange plate; 304. Cutting plate;

[0043] 4. Limiting strip;

[0044] 5. Battery module;

[0045] 6. Lower box side panel;

[0046] 7. Support cylinder;

[0047] 8. Pressure relief port. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0050] Example 1

[0051] See Figure 1 , Figure 2 and Figure 3 A battery housing includes a lower housing end plate 1, a liquid cooling plate 2, a pressure equalizer 3, a limiting strip 4, a battery module 5, a lower housing side plate 6, a supporting cylinder 7, a pressure relief port 8, and a top cover.

[0052] The lower housing end plate 1, the lower housing side plate 6, and the upper cover constitute the housing body; the liquid cooling plate 2 is integrated into the housing body; the battery module 5 is fixed on the liquid cooling plate 2; the lower end of the supporting cylinder 7 is fixed on the battery module 5; the pressure equalizer 3 is located on the upper part of the supporting cylinder 7 and can rotate around the center of the supporting cylinder 7; the pressure relief port 8 is located on the battery module 5; and the liquid cooling plate 2 is provided with a limit strip 4.

[0053] See Figure 4 and Figure 5 The pressure equalizer 3 is made of permanent magnets and includes a radial plate 301, a middle plate 302, a flange plate 303, and a cut-out plate 304. The middle plate 302 is mounted on the supporting cylinder 7 and can rotate around it. Multiple rotating blades are distributed around the circumference of the middle plate 302. Each rotating blade includes a radial plate 301 and a flange plate 303. The upper surface of the flange plate 303 is the cut-out plate 304. The pressure equalizer 3 is a permanent magnet. The supporting cylinder 7 contains an electromagnetic coil, which is powered by the low-voltage wiring harness of the battery assembly and forms an electromagnetic field after being energized. The electromagnetic coil receives signals from the battery management system to control the rotation and stop of the pressure equalizer 3 located at the upper end, and the response speed is ≤10m / s.

[0054] The pressure equalizer 3 is positioned close to the pressure relief port 8, and the straight-line distance between the pressure relief port 8 and the pressure equalizer 3 is ≤0.2m. After the power battery experiences thermal runaway, the pressure relief port 8 will rupture due to pressure. The pressure equalizer 3 can quickly expel harmful air pressure through the pressure relief port 8 by rotating rapidly, effectively delaying the thermal runaway of the battery.

[0055] Example 2

[0056] A battery assembly includes a battery housing. In a battery assembly equipped with the battery housing described in Embodiment 1, when the battery experiences thermal runaway, the pressure relief port will rupture due to pressure. A pressure equalizer, through rapid rotation, can quickly expel harmful gas pressure from the battery through the pressure relief port, effectively delaying battery thermal runaway.

[0057] Example 3

[0058] An electric vehicle includes a vehicle body and a battery assembly as described in Embodiment 2. The battery assembly is mounted on the vehicle body. In an electric vehicle equipped with a battery assembly, when the battery experiences thermal runaway, the pressure relief port will rupture due to pressure. The pressure equalizer, through rapid rotation, can quickly expel harmful air pressure through the pressure relief port from the battery, effectively delaying battery thermal runaway. This solves the problem in the prior art where the internal air pressure of the power battery cannot be balanced, resulting in a slow air pressure relief rate during battery thermal runaway.

[0059] Example 4

[0060] The limiting rotation area V of the pressure balancer 3 is determined based on the battery thermal runaway delay safety factor HBS and the battery pressure equalization factor LHS:

[0061] The limiting rotation area V of the pressure balancer 3 is given by: V = HBS / CC*LHS / lnA*tanA(lnA*expA)*lnA*tanA(sinA*exp(A)*A*A*cot(A)*(2[lnA*tanA][9 / 5(A*sinC / A*C)][lnA*tanA][1 / 6(A / sinC C)], where CC is the battery structure threshold coefficient, taken as 0.53-0.62; A is the pressure rotation compensation parameter, taken as 9°>A>0°; and C is the pressure balance correction safety factor.

[0062] The diameter D of the pressure balancer 3 and the thickness H of the intermediate plate (302) are determined based on the limit rotation area V of the pressure balancer 3.

[0063] The diameter D is given by: D = V / (BN*E) / (BN*E)*0.55*lnA*tanA(lnA*tanAA*expA)*lnA*tanA(sinA*exp(A), where BN is the design height installation dimension; E is the battery arrangement dimension coefficient, which is taken as 1.23-1.53.

[0064] The thickness H=V*tan(A)*π[lnA*tanAA*tanA / lgC*expA*exp(A)]^2*lnA*tanA(A)*(3[lnA*tanA][1 / 5 (A*sinC / cosA*C)][lnA*tanA][1 / 6(A / sinC / tanC)]*lnA*sinA*expA*lnA*tanA(sinA*expA).

[0065] All parameters need to be corrected and fed back based on CAE and CFD simulation results.

[0066] Example 5

[0067] A method for controlling a battery housing includes the following steps:

[0068] Step 1: The battery management system collects the air pressure value of the battery pack through sensors inside the battery pack;

[0069] Step 2: The battery management system determines whether the battery box needs pressure equalization based on the collected air pressure signal. There are three modes: no working mode, normal mode, extreme mode, and thermal runaway mode.

[0070] Step 3: Define the highest air pressure received by the battery management system as SM, the lowest air pressure of the battery as SN, the air pressure difference SW = SM - SN, the safe air pressure threshold as SA, and the temperature difference as calculated from the test data every 100 milliseconds.

[0071] No-operation mode: SM≤SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW is ≤9*(1-lgC*expC*cosC*cos(2*C)lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, taken as 0.951<C<0.964; the battery management system is inactive, the supporting cylinder 7 is not working, and the pressure equalizer 3 does not rotate;

[0072] Normal mode: SA / (1-lgC*expC*cosC*cotC*lgC*expC)≥SM>SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW is ≤9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues a command to support cylinder 7 to work, and the pressure equalizer 3 rotates at 30% of its maximum speed, and feedback action is performed after 2 minutes;

[0073] Extreme mode: SM > SA / (1-lgC*expC*cosC*cotC*lgC*expC) or the curvature of SW > 9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues a command to support cylinder 7 to work, and the pressure equalizer 3 rotates at 90% of its maximum speed, and feedback action is performed after 3 minutes;

[0074] Thermal runaway mode: When the battery management system receives a battery thermal runaway alarm, it issues a command to support cylinder 7 to work and pressure equalizer 3 to rotate at 100% maximum speed until the system fails.

[0075] Step 4, Action Feedback: Provide signal feedback for the collected battery air pressure.

[0076] Signal judgment: SM≤SA / (1.03-lgC*expC*lgC*exp(C*C)*lgC*expC) and the curvature of SW change≤9*(1-lgC*expC*cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, taken as 0.951<C<0.964; if the criteria are not met, repeat step three; otherwise, exit control.

[0077] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A battery housing, characterized in that, The enclosure includes a lower end plate (1), a liquid cooling plate (2), a pressure equalizer (3), a limiting strip (4), a battery module (5), a lower side plate (6), a supporting cylinder (7), a pressure relief port (8), and a top cover; the lower end plate (1), the lower side plate (6), and the top cover constitute the enclosure body; the liquid cooling plate (2) is integrated into the enclosure body; the battery module (5) is fixed on the liquid cooling plate (2); the lower end of the supporting cylinder (7) is fixed on the battery module (5); the pressure equalizer (3) is located on the upper part of the supporting cylinder (7) and can rotate around the center of the supporting cylinder (7); the pressure relief port (8) is located on the battery module (5); the liquid cooling plate (2) is provided with a limiting strip (4); The pressure equalizer (3) includes a radial plate (301), a middle plate (302), a flange plate (303), and a cutting plate (304); the middle plate (302) is disposed on the supporting cylinder (7) and can rotate around the supporting cylinder (7); multiple rotating blades are distributed around the circumference of the middle plate (302); each rotating blade includes a radial plate (301) and a flange plate (303); the upper surface of the flange plate (303) is the cutting plate (304). The straight-line distance between the pressure relief port (8) and the pressure equalizer (3) is ≤0.2m; The pressure equalizer (3) is a permanent magnet; The supporting cylinder (7) contains an electromagnetic coil, which is powered by the low-voltage wiring harness of the battery assembly and forms an electromagnetic field after being energized. The electromagnetic coil receives signals from the battery management system and controls the rotation of the pressure equalizer (3) located at the top.

2. The battery housing according to claim 1, characterized in that, The control method for the battery box includes the following steps: Step 1: The battery management system collects the air pressure value of the battery pack through sensors inside the battery pack; Step 2: The battery management system determines whether the battery box needs pressure equalization based on the collected air pressure signal. There are four modes: no working mode, normal mode, extreme mode, and thermal runaway mode. Step 3: Define the highest air pressure received by the battery management system as SM, the lowest air pressure of the battery as SN, the air pressure difference SW = SM - SN, the safe air pressure threshold as SA, and the temperature difference as calculated from the test data every 100 milliseconds. No working mode: SM≤SA / (1.03-lgC*expC* lgC*exp(C*C)*lgC*expC) and the curvature of SW is ≤9*(1- lgC*expC* cosC*cos(2*C)lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, which is 0.951<C<0.964; the battery management system is inactive, the support cylinder (7) is not working, and the pressure equalizer (3) does not rotate; Normal mode: SA / (1-lgC*expC* cosC*cotC*lgC*expC)≥SM>SA / (1.03-lgC*expC* lgC*exp(C*C)*lgC*expC) and the curvature of SW change ≤9*(1- lgC*expC* cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues an instruction to support the cylinder (7) to work, the pressure equalizer (3) rotates at 30% maximum speed, and feedback action is performed after 2 minutes; Extreme mode: SM>SA / (1-lgC*expC* cosC*cotC*lgC*expC) or the curvature of SW>9*(1-lgC*expC* cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient; the battery management system issues a command to support the cylinder (7) to work, the pressure equalizer (3) rotates at 90% of the maximum speed, and feedback action is performed after 3 minutes; Thermal runaway mode: When the battery management system receives a battery thermal runaway alarm, the battery management system issues an instruction to support the cylinder (7) to work, and the air pressure equalizer (3) rotates at 100% maximum speed until the system fails; Step 4, Action Feedback: Provide signal feedback for the collected battery air pressure. Signal judgment: SM≤SA / (1.03-lgC*expC* lgC*exp(C*C)*lgC*expC) and the curvature of SW change≤9*(1- lgC*expC* cosC*cotC*lgC*expC*lgC*exp(cosC)), where C is the thermal runaway gas compensation coefficient, taken as 0.951<C<0.964; if the standard is not met, repeat step three; otherwise, exit control.

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