New energy automobile power battery pack

Abstract

The invention discloses a new energy automobile power battery pack which comprises a shell, a battery module and a fire extinguishing medium generation unit, the battery module and the fire extinguishing medium generation unit are arranged in the shell, and a pressure relief opening is formed in the shell; the fire extinguishing medium generating unit and the pressure relief opening are arranged at the front end and the rear end of the interior of the shell correspondingly. According to the battery pack, the fire extinguishing medium generation unit and the pressure relief opening are arranged at the front end and the rear end of the interior of the shell correspondingly, it is guaranteed that after the fire extinguishing medium generation unit is triggered, sprayed fire extinguishing media can be completely conducted from the front end to the rear end, internal air is exhausted outwards, and therefore the internal space of the shell is completely filled; and the situation that the fire extinguishing medium cannot be conveyed to a battery cell area with thermal runaway after the fire extinguishing medium generation unit is triggered is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery pack management equipment, and in particular relates to a new energy vehicle power battery pack. Background Art

[0002] As a clean energy alternative, lithium-ion batteries are safe, have a long cycle life, are non-toxic, and pollution-free. If the target voltage is higher, it needs to be achieved by connecting batteries in series. The safety of lithium batteries has always been a big problem. In industrial design, in order to ensure the safety of the battery pack, the battery management system provides protection against overcharge, over-discharge, overcurrent, and overheating. However, the internal short circuit of the battery is a probabilistic event that cannot be prevented and predicted. Although this is only a small probability event, the occurrence of an internal short circuit may lead to devastating consequences.

[0003] In order to obtain a high voltage platform, when multiple battery cells are connected in parallel, the traditional solution is generally to connect the total positive-total negative-total positive-total negative of the modules in close series, so as to obtain a battery pack with a large capacity and high voltage platform. Currently, the battery cells on the market are generally equipped with a pressure relief valve to release the gas generated in the battery during thermal runaway. Due to the close fit of the total positive and negative between the modules, when a battery cell has thermal runaway, the high temperature and high pressure generated will inevitably be transmitted to its adjacent modules, thereby greatly increasing the possibility of a chain reaction of thermal runaway of the battery cells in the adjacent modules.

[0004] After the battery cells inside the battery pack thermally runaway, the fire extinguishing medium generating unit is triggered to spray the fire extinguishing medium into the battery pack shell. At this time, the air pressure inside the battery pack rises rapidly until the shell is damaged and the pressure is released outward. However, in actual applications, due to the uncertainty of the pressure relief position of the shell, once the pressure relief position is close to the fire extinguishing medium generating unit, the sprayed fire extinguishing medium cannot fill the interior of the battery pack. The fire extinguishing medium cannot be filled to the position of the battery cell where thermal runaway occurs, resulting in failure of thermal runaway flame retardancy of the battery cell. Therefore, targeted improved design is needed. Summary of the invention

[0005] The purpose of the present invention is to provide a new energy vehicle power battery pack for use to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a new energy vehicle power battery pack, comprising a housing, a battery module and a fire extinguishing medium generating unit arranged inside the housing,

[0007] The housing is provided with a pressure relief port;

[0008] The fire extinguishing medium generating unit and the pressure relief port are respectively arranged at the front and rear end positions inside the shell.

[0009] A monitoring mechanism for triggering the fire extinguishing medium generating unit is provided inside the housing (1) after detecting an abnormal internal state of the battery pack.

[0010] Preferably, the housing is composed of a cylindrical member with an integral structure, a front end cover plate and a rear end cover plate that close the front and rear openings.

[0011] Preferably, the pressure relief port is arranged on the rear end cover plate;

[0012] Preferably, the connection between the lower edge of the rear end cover plate and the cylindrical member is set as the pressure relief port.

[0013] Preferably, the rear end cover plate is made of a high resilience metal material. The pressure relief port has two states. One is the pressure relief state in which the pressure relief port opens when the internal pressure of the housing is too high, and the other is the closed state in which the pressure relief port closes when the internal pressure of the housing is normal.

[0014] Preferably, the fire extinguishing medium generating unit is arranged on the front end cover plate of the housing.

[0015] Preferably, the fire extinguishing medium generating unit is an aerosol device.

[0016] Preferably, the monitoring mechanism includes a lead wire assembly disposed on the surface of the battery module, and one end of the lead wire assembly is introduced into the fire extinguishing medium generating unit.

[0017] Preferably, the monitoring mechanism further includes a smoke sensor disposed inside the housing.

[0018] Preferably, the monitoring mechanism further includes a BMS detection unit for monitoring the temperature and voltage change values of the battery cells.

[0019] Technical effects and advantages of the present invention: This new energy vehicle power battery pack,

[0020] 1. By setting the relative positions of the pressure relief port and the fire extinguishing medium generating unit, it is ensured that the ejected aerosol can conduct from one end to the other end inside the housing of the housing until the internal air is exhausted, and the aerosol completely fills the housing, avoiding the problem that the pressure relief port near the fire extinguishing medium generating unit causes the inability to fill the internal space of the housing;

[0021] In addition, the housing is composed of a cylindrical member with an integral structure, a front end cover plate and a rear end cover plate that close the front and rear openings, greatly reducing the probability of damage in the middle, reducing the number of connections on the battery pack housing, facilitating the setting of the pressure relief port, and arranging the pressure relief port at the rear cover plate to guide the flame to discharge downward at the rear after the battery cells explode, improving safety;

[0022] Moreover, the rear end cover plate is made of a metal material with high resilience such as aluminum alloy. After the aerosol is ejected and all the air inside the housing is exhausted, when the pressure is relieved until the air pressure inside and outside the housing is relatively balanced, the pressure relief port automatically closes. At this time, the air pressure inside the housing is still higher than the outside, so that the outside air will not flow back into the housing, thus ensuring that the aerosol continues to be filled inside the housing and avoiding the situation where the aerosol continuously leaks and the thermal runaway of the battery cell cannot be continuously suppressed.

[0023] 2. By using the lead wire assembly to detect the instantaneous temperature of the battery cell, the smoke sensor to detect the smoke concentration inside the battery pack housing, and the BMS detection unit to monitor the changes in data such as temperature rise and voltage in real time, it is possible to detect whether the battery cell in the battery pack will undergo thermal runaway at an earlier stage, thereby preventing the entire battery pack from undergoing thermal runaway and causing deflagration, minimizing both the loss of the battery cell and the difficulty of flame retardancy during thermal runaway, and achieving higher detection efficiency and flame retardancy trigger accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a bottom view structural schematic diagram of the present invention;

[0025] Figure 2 is a side view structural schematic diagram of the present invention.

[0026] In the figure: 1. Housing; 110. Cylindrical member; 120. Front end cover plate; 130. Rear end cover plate;

[0027] 2. Battery module; 3. Fire extinguishing medium generating unit; 4. Pressure relief port; 5. Lead wire assembly; 6. Smoke sensor; 7. BMS detection unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. 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.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the 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 thus should not be construed as a limitation to the present invention.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, terms such as "installation", "provided with", "connection", etc. should be understood in a broad sense. For example, "connection" 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 components. 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 circumstances.

[0031] The present invention provides a Figure 1-2 power battery pack for a new energy vehicle as shown, including a housing 1, a battery module 2 and a fire extinguishing medium generating unit 3 disposed inside the housing 1. The fire extinguishing medium generating unit 3 is an aerosol device. Through the triggering of the fire extinguishing medium generating unit 3 inside the housing 1, aerosol is ejected to fill the inside of the housing 1, expelling the internal air, achieving the effect of suppressing the combustion of the battery cells, preventing the thermal runaway of the battery cells from spreading to other battery cells, and reducing losses.

[0032] A pressure relief port 4 is provided on the housing 1; the fire extinguishing medium generating unit 3 and the pressure relief port 4 are respectively disposed at the front and rear end positions inside the housing 1. By setting the relative positions of the pressure relief port 4 and the fire extinguishing medium generating unit 3, it is ensured that when the internal pressure of the housing 1 is too high after the aerosol fills the internal space of the housing 1, the pressure relief port 4 opens, thereby relieving pressure outward. And because the fire extinguishing medium generating unit 3 and the pressure relief port 4 are respectively disposed at the front and rear end positions inside the housing 1, it is ensured that the ejected aerosol can conduct from one end to the other end inside the housing 1 of the housing 1 until the internal air is expelled, and the aerosol completely fills the housing 1, avoiding the problem that the pressure relief port 4 near the fire extinguishing medium generating unit 3 causes the inability to fill the internal space of the housing 1, and ensuring the effect of suppressing the thermal runaway of the battery cells.

[0033] The housing 1 is composed of a cylindrical member 110 with an integral structure, a front end cover plate 120 and a rear end cover plate 130 that close the front and rear openings. The cylindrical member 110 is a square cylinder or a circular cylinder. The integral structure of the cylindrical member 110 in the middle can greatly reduce the probability of breakage in the middle, reduce the number of connections on the battery pack housing 1, and facilitate the setting of the pressure relief port 4.

[0034] The pressure relief port 4 is provided on the rear end cover plate 130. When inserting the battery pack into the battery compartment at the bottom of the vehicle, setting the pressure relief port 4 on the rear end cover plate 130 can keep it away from the opening of the battery compartment, avoiding the risk that once the battery pack has a thermal runaway, the generated flame directly rushes out of the opening and causes greater risks to the surrounding of the vehicle battery compartment.

[0035] The connection between the lower edge of the rear end cover 130 and the cylindrical part 110 is set as a pressure relief port 4. There is no need to separately open a pressure relief port 4 on the rear end cover 130. Only the connection strength of one of the adjacent sides between the rear end cover 130 and the cylindrical part 110 needs to be less than that of the other three sides. When the internal air pressure of the housing 1 is too high, the side with lower connection strength will open to achieve pressure relief. The pressure relief port 4 is arranged at the lower edge of the rear end cover 130, which can guide the flame to impact the bottom of the battery compartment, avoiding the flame directly impacting the bottom of the battery compartment after thermal runaway and causing internal circuits and other equipment, further improving safety.

[0036] The rear end cover 130 is made of a metal material with high resilience such as aluminum alloy. The pressure relief port 4 has two states. One is the pressure relief state in which the pressure relief port 4 opens when the internal air pressure of the housing 1 is too high. The other is the closed state in which the pressure relief port 4 is closed when the internal air pressure of the housing 1 is normal. After ensuring that all the air inside the housing 1 is discharged after the aerosol is ejected and the pressure is relieved until the internal and external air pressures of the housing 1 tend to be balanced, the pressure relief port 4 automatically closes. At this time, the internal air pressure of the housing 1 is still higher than the outside, and external air will not backflow into the housing 1, thereby ensuring that the aerosol continues to fill the inside of the housing 1 and avoiding the situation where the aerosol cannot continuously suppress the thermal runaway of the battery cells after continuous loss.

[0037] The fire extinguishing medium generating unit 3 is arranged on the front end cover 120 of the housing 1. By arranging the fire extinguishing medium generating unit 3 at the front end cover 120, it is ensured that after the fire extinguishing medium generating unit 3 is triggered, the released aerosol can spread along the housing 1 all the way towards the pressure relief port 4 at the rear end cover 130, thereby exhausting the air inside the housing 1 and continuously filling the internal space of the battery pack.

[0038] The surface of the battery module 2 is provided with a lead wire assembly 5, and one end of the lead wire assembly 5 is introduced into the fire extinguishing medium generating unit 3. The temperature of the battery cells is detected through the arranged lead wire assembly 5. Once the battery cells undergo thermal runaway and the temperature exceeds the ignition point of the lead wire assembly 5, causing the self-ignition of the lead wire assembly 5, the combustion will be guided all the way into the fire extinguishing medium generating unit 3, thereby quickly triggering the fire extinguishing medium generating unit 3 to eject the fire extinguishing medium.

[0039] A smoke sensor 6 is also arranged inside the housing 1. When the battery cells undergo thermal runaway, intense smoke will be generated before deflagration. Therefore, detecting the smoke can often detect whether the battery cells are about to fail faster, thereby triggering the fire extinguishing medium generating unit 3 more timely and reducing the loss and the difficulty of suppressing combustion to the lowest level.

[0040] The battery pack further includes a BMS detection unit 7 for detecting the voltage and temperature values of the battery cells in the battery pack during the stage change. The BMS detection unit 7 monitors in real time the temperature rise and voltage changes of each battery cell in the battery pack. When an abnormality is detected, it directly triggers the fire extinguishing medium generating unit 3 to eject the fire extinguishing medium by means of electric triggering, so as to block the thermal runaway of the battery cells at a relatively earlier stage, making it more convenient to repair and recycle the battery pack, reducing costs and the difficulty of flame retardancy.

[0041] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power battery pack for a new energy vehicle, comprising a housing (1), a battery module (2) and a fire extinguishing medium generating unit (3) disposed inside the housing (1), characterized in that: A pressure relief port (4) is provided on the housing (1); The fire extinguishing medium generating unit (3) and the pressure relief port (4) are respectively arranged at the front and rear end positions inside the housing (1); A monitoring mechanism is arranged inside the housing (1) for triggering the fire extinguishing medium generating unit after detecting an abnormal internal state of the battery pack.

2. The power battery pack for a new energy vehicle according to claim 1, characterized in that: The housing (1) is composed of a cylindrical member (110) with an integral structure, a front end cover plate (120) and a rear end cover plate (130) that close the front and rear openings.

3. The power battery pack for a new energy vehicle according to claim 1, characterized in that: The pressure relief port (4) is arranged on the rear end cover plate (130).

4. The power battery pack for a new energy vehicle according to claim 1, characterized in that: The connection between the lower edge of the rear end cover plate (130) and the cylindrical member (110) is set as the pressure relief port (4).

5. The power battery pack for a new energy vehicle according to claim 3 or 4, characterized in that: The rear end cover plate (130) is made of a high resilience metal material; The pressure relief port (4) has two states. One is the pressure relief state in which the pressure relief port (4) opens when the internal pressure of the housing (1) is too high, and the other is the closed state in which the pressure relief port (4) is closed when the internal pressure of the housing (1) is normal.

6. The power battery pack for a new energy vehicle according to claim 5, characterized in that: The fire extinguishing medium generating unit (3) is arranged on the front end cover plate (120) of the housing (1).

7. The power battery pack for a new energy vehicle according to claim 1, characterized in that: The fire extinguishing medium generating unit (3) is an aerosol device.

8. The power battery pack for a new energy vehicle according to claim 1, characterized in that: The monitoring mechanism includes a lead wire assembly (5) arranged on the surface of the battery module (2), and one end of the lead wire assembly (5) is introduced into the fire extinguishing medium generating unit (3).

9. The power battery pack for a new energy vehicle according to claim 8, characterized in that: The monitoring mechanism further includes a smoke sensor (6) arranged inside the housing (1).

10. The power battery pack for a new energy vehicle according to claim 9, characterized in that: The monitoring mechanism further includes a BMS detection unit (7) for monitoring the temperature and voltage change values of the battery cells.

Images