CN111584792B

CN111584792B - Battery module

Info

Publication number: CN111584792B
Application number: CN202010317515.XA
Authority: CN
Inventors: 郭盛昌; 王爽; 赵建雄
Original assignee: Chongqing Jinkang Power New Energy Co Ltd
Current assignee: Chongqing Jinkang Power New Energy Co Ltd
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2022-11-29
Anticipated expiration: 2040-04-21
Also published as: CN111584792A

Abstract

The invention discloses a battery module, comprising: the battery comprises battery cells, a plurality of battery cells and a plurality of exhaust valves, wherein the battery cells are arranged and provided with the exhaust valves; the fire extinguishing device comprises a liquid discharging device used for cooling fluid circulation, the liquid discharging device comprises a normal state and a liquid discharging state, and when the liquid discharging state is reached, the cooling fluid flows out of the liquid discharging device to cool the battery core; the fire extinguishing device is provided with a first heat conduction hole, and the first heat conduction hole is arranged right opposite to the exhaust valve to form an exhaust channel for guiding gas exhausted from the exhaust valve; the liquid drainage device is arranged in the first heat conduction hole. An exhaust channel is formed outside the exhaust valve of the battery core and used for guiding gas exhausted by the exhaust valve, so that the phenomenon that the fusing position of the gas caused by deviation of an exhaust path is uncontrollable is avoided, and the safety of the battery is improved.

Description

Battery module

Technical Field

The invention relates to the technical field of new energy automobile power battery safety, in particular to a battery module.

Background

With the development of new energy automobiles, power batteries have acquired larger development and growth space, and people have higher and higher requirements on the endurance mileage of the power batteries, which requires that the energy density of the power batteries is improved. Along with the improvement of the energy density of the battery core, the thermal stability of the battery is difficult to be ensured, and the accidents of fire and explosion caused by thermal runaway are increased. Therefore, the thermal safety of new energy vehicles is becoming more and more important. When a certain electric core is on fire or is out of control due to heat, how to avoid causing other electric cores to be on fire and spread finally to cause vehicle on fire, so as to cause casualties and property loss, and whether to leave enough time for passengers to evacuate and escape or not, or when the electric core is out of control due to heat, the electric core is not burnt and does not spread, so that the electric core becomes an important index of the safety of the new energy automobile.

In the prior art, when the battery in the battery pack is out of control due to heat, certain fireproof heat-insulating materials can be placed between the battery and the battery, so that heat transfer is blocked, the time of heat transfer is prolonged, and the time for passengers to escape is obtained. In the battery package, also can detect every free voltage of battery through battery management system BMS, 2 temperature values are adopted to general module, or place smog, gas sensor etc. in the battery package, carry out the warning in advance when battery monomer takes place thermal runaway, remind the passenger to flee from. The battery pack can also put a certain amount of dry and wet fire extinguishing agents for extinguishing fire under limited conditions.

In a conventional battery pack having a fire extinguishing device, the fire extinguishing device is disposed near an explosion-proof valve of the battery, and the fire extinguishing device is broken/opened to flow out a coolant in response to a high-temperature and high-pressure gas ejected from the explosion-proof valve, thereby extinguishing the fire and cooling the battery. However, the gas/flame route sprayed by the explosion-proof valve is uncontrollable, deviation easily occurs, the contact position of flame and the fire extinguishing device is uncontrollable, the fusing position of the fire extinguishing device is uncontrollable, the cooling liquid flowing out from the fusing port can not be aligned to the thermal runaway battery core, and even fusing is not realized, so that the fire extinguishing device can not accurately and quickly respond to the thermal runaway of the battery, and the stability of the safety performance of the battery is influenced. Therefore, how to provide a technical solution to solve the above problems has become an urgent technical problem to be solved by those skilled in the art.

Disclosure of Invention

In view of this, an embodiment of the present invention provides a battery module, which is used to solve the problem of unstable safety performance of a battery pack in the prior art.

The present invention provides a battery module, including: the battery comprises battery cells, a plurality of battery cells and an exhaust valve, wherein the battery cells are arranged in an array manner; the fire extinguishing device comprises a liquid discharging device used for cooling fluid circulation, wherein the liquid discharging device comprises a normal state and a liquid discharging state, and when the fire extinguishing device is in the liquid discharging state, the cooling fluid flows out of the liquid discharging device to cool the battery cell; the fire extinguishing device is provided with a first heat conduction hole which is arranged right opposite to the exhaust valve to form an exhaust passage for guiding gas exhausted from the exhaust valve; the drain device is arranged in the first heat conduction hole.

Further, the drain is a low melting point drain.

Furthermore, a flow passage is arranged on the fire extinguishing device, and the flow passage connects the plurality of liquid discharging devices in series. Optionally, the fire extinguishing apparatus is provided with a flow passage, and the flow passage connects a plurality of the liquid discharging devices in parallel.

Further, the drain is tubular in shape. Optionally, the drainage device comprises a tubular body and a reservoir disposed in a middle section of the tubular body. The surface of the liquid storage cavity, which is opposite to the exhaust valve, forms a structure which is concave towards the direction far away from the exhaust valve.

Furthermore, a signal acquisition device is further arranged between the fire extinguishing device and the battery core, a second heat conduction hole and a thermal runaway monitoring device are arranged on the signal acquisition device, the second heat conduction hole is just opposite to the exhaust valve, and the thermal runaway monitoring device is arranged in the second heat conduction hole.

Further, the thermal runaway monitoring device comprises a smoke sensor and/or a light sensitive sensor.

Further, the thermal runaway monitoring device is integrated with the signal acquisition device.

In summary, in the invention, the exhaust channel is formed at the position opposite to the exhaust valve of the battery cell, and is used for guiding the gas/flame exhausted by the exhaust valve, so that the uncontrollable fusing position caused by deviation of the exhaust path of the gas/flame is avoided, the phenomenon that the exhausted cooling liquid cannot be accurately sprayed onto the thermal runaway battery cell after fusing is avoided, and the safety of the battery is improved. The liquid storage cavity is arranged on the low-melting-point liquid drainage device, so that the contact area between the liquid storage cavity and gas/flame is increased while the capacity of cooling liquid is increased, and the safety stability of the battery is further improved. The bottom surface of the liquid storage cavity is arranged to be of an inwards concave structure, so that the effect of gathering gas/flame is achieved, and the safety stability of the battery is further improved.

Drawings

Fig. 1 is an exploded view illustrating a structure of a battery module according to a first embodiment of the present invention;

FIG. 2 is a schematic view of the fire suppression apparatus of FIG. 1;

FIG. 3 is a schematic structural diagram of the signal acquisition device of FIG. 1;

fig. 4 is a partial sectional view of a battery module according to a first embodiment of the present invention;

FIG. 5 is an enlarged view of a portion of FIG. 4;

FIG. 6 is a schematic view of a fire extinguishing apparatus according to a second embodiment of the present invention;

FIG. 7 is a partial cross-sectional view of the low melt drain of FIG. 6.

Wherein the reference numerals are as follows:

1-electric core; 11-an exhaust valve;

2-a fire extinguishing device; 21-a flow channel; 22-a first heat conduction hole; 23-a drain; 24-a liquid inlet; 25-a liquid outlet; 26-the extinguishing device body; 231-a tubular body; 232-liquid storage cavity; 233-bottom of liquid storage cavity;

3-a conductive medium;

4-a signal acquisition device; 41-a second heat conduction hole; 42-thermal runaway monitoring; 43-a temperature sensor; 44-a voltage sensor;

5-module fixing member.

Detailed Description

The structure of the battery module disclosed in the present application will be described in further detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following detailed description and claims. It is to be noted that the drawings are in a very simplified form and are each provided with a non-precision ratio for the purpose of convenience and clarity in assisting in describing the embodiments of the present invention.

Example one

Referring to fig. 1 and 2, the battery module according to the present invention includes a battery core 1, a conductive medium 3, and a fire extinguishing apparatus 2. Wherein electric core 1 is cuboid electric core or cylinder electric core, and every electric core 1 is provided with discharge valve 11 at the top, and electric core 1 arranges in proper order. The conductive medium 3 is disposed on the top of the battery cell 1, and electrically connects the battery cell 1, and optionally, the conductive medium 3 electrically connects the battery cell 1 in a serial or parallel manner. Extinguishing device 2 corresponds discharge valve 11 and sets up, refers to fig. 1, and extinguishing device 2 sets up in the top of electric core 1, when taking place thermal runaway, puts out a fire to electric core 1 and handles.

As shown in fig. 2, the fire extinguishing apparatus 2 includes a flow passage 21, a first heat transfer hole 22, a liquid discharge device 23, a liquid inlet 24, a liquid outlet 25, and an extinguishing apparatus body 26. Wherein, extinguishing device body 26 forms the upper cover for the battery module, and first heat conduction hole 22 sets up on extinguishing device body 26, and corresponds the setting of discharge valve 11 of electric core 1, forms exhaust passage above discharge valve 11 of electric core 1. When the battery cell 1 is out of control due to heat, the high-temperature and high-pressure gas ejected/discharged by the exhaust valve 11 enters the exhaust passage formed by the first heat conduction hole 22, and the exhaust passage guides the high-temperature and high-pressure gas to be discharged, so that the high-temperature and high-pressure gas is directionally discharged.

Further, the shape of the drain 23 is a tubular structure, and the drain 23 is a low melting point drain, in this application, the low melting point means that when the battery is thermally out of control, high-temperature and high-pressure gas or flame gas is ejected/discharged through the exhaust valve, and when the battery is in contact with the drain 23, the drain 23 may be fused to allow the cooling fluid to flow out, and it can be understood that the melting point of the drain 23 is lower than the temperature of the gas discharged from the exhaust valve. The drain 23 may be a plastic or resin with a low melting point, the drain 23 having a melting point below 500 c, preferably below 300 c. In this embodiment, the drain 23 may be a nylon tube.

The liquid discharging device 23 is used for circulating cooling fluid, and includes a normal state and a liquid discharging state, and when the liquid discharging device is in the liquid discharging state, the cooling fluid flows out of the liquid discharging device to cool the battery cell; the flowing back state is the state that takes place the fusing, and cooling fluid flows out by the fusing department, sprays the cooling to electric core 1. The cooling fluid may be water or a liquid containing a coolant. Further, drain 23 can either melt completely or partially, as long as can break when encountering high-temperature gas, makes the cooling fluid flow out, puts out a fire to the battery and cools down, all is in the scope of this application.

It should be further noted that, in the present embodiment, the liquid drainage device 23 is disposed in the first heat conduction hole 22, preferably horizontally disposed in the first heat conduction hole 22, and two ends of the liquid drainage device are fixed on the inner side wall of the first heat conduction hole 22. It will be appreciated that the drain 23 may be secured to the inner side wall of the first heat-transfer aperture 22 in a manner conventional in the art. Referring to fig. 2, a liquid discharge device 23 is disposed in each of the first heat conduction holes 22.

In the embodiment of the present invention, the fire extinguishing apparatus body 26 is further provided with a flow passage 21, a liquid inlet 24 and a liquid outlet 25. The flow passage 21 communicates with the liquid line through a liquid inlet 24 and a liquid outlet 25. The liquid pipeline can be a cooling pipeline in the battery module or other liquid pipelines outside the battery module. Referring to fig. 2, the flow channel 21 connects each drain 23 in series to form a closed flow chamber. Alternatively, the flow channel 21 may connect each drainage device 23 with the liquid inlet 24 and the liquid outlet 25 respectively to form a plurality of parallel closed flow chambers, and compared with the serial connection mode, the plurality of parallel flow chambers may shorten the distance between the liquid inlet 24 and the low melting point device 23, thereby further realizing the quick response to the thermal runaway of the battery.

Referring to fig. 1 and 3, the battery module further includes a signal collecting device 4 for collecting and detecting an internal environment of the battery module. The signal acquisition device 4 is provided with a second heat conduction hole 41, and the second heat conduction hole 41 is arranged above the exhaust valve 11. Referring to fig. 5 and 6, the second heat conduction hole 41 is disposed between the first heat conduction hole 22 and the exhaust valve 11, the second heat conduction hole 41 and the second heat conduction hole 22 together form an exhaust channel, and when thermal runaway occurs in the battery cell 1, high-temperature and high-pressure gas ejected from the exhaust valve 11 enters the exhaust channel formed by the first heat conduction hole 22 and the second heat conduction hole 41 together, so that directional discharge of the high-temperature and high-pressure gas is realized.

Further, the signal collecting device 4 is provided with a thermal runaway monitoring device 42 disposed on the second heat conducting hole 41, referring to fig. 4 and 5, the thermal runaway monitoring device 42 is disposed in the second heat conducting hole 41, and preferably passes through the second heat conducting hole 41 in a horizontal direction, so that the thermal runaway monitoring device 42 can be accurately and rapidly contacted with the high-temperature and high-pressure gas/flame sprayed by the exhaust valve, and the thermal runaway information can be rapidly obtained.

Further, the thermal runaway monitoring device 42 is at right angles to the projection of the drainage device 23 disposed in the first heat conduction hole 22 in the horizontal direction. Because the high-temperature and high-pressure gas/flame sprayed from the explosion-proof valve firstly contacts the thermal runaway monitoring device 42 and then contacts the liquid discharge device 23 in the process of passing through the exhaust passage. The thermal runaway monitoring device 42 and the liquid discharging device 23 are arranged in a right angle in the horizontal direction, so that the influence of the thermal runaway monitoring device 42 on a high-temperature and high-pressure gas discharging path can be reduced to the maximum extent, and the accuracy of the response of the liquid discharging device 23 on the high-temperature and high-pressure gas is further ensured. The thermal runaway monitoring device 42 is a smoke sensor, a light sensor, or a smoke sensor and a light sensor. Referring to fig. 2, the thermal runaway monitoring device 42 extends along the arrangement direction of the second heat conduction holes 41. This arrangement may allow the thermal runaway monitoring device 42 to be more compact.

Further, the signal acquisition device 4 is further provided with a temperature sensor 43 and a pressure sensor 44 for sensing the temperature and the pressure inside the battery module. The temperature sensor 43, the pressure sensor 44 and the thermal runaway monitoring device 42 are integrated into a whole, so that more reliable signals are provided for the thermal runaway early warning.

In this embodiment, the thermal runaway monitoring device 42 and the drain device 23 are respectively disposed in the exhaust passage, thereby further improving the safety of the battery module. When thermal runaway occurs, the thermal runaway monitoring device 42 can quickly monitor abnormal signals and send out alarm signals to remind passengers of escaping; meanwhile, high-temperature and high-pressure gas sprayed/discharged by the exhaust valve passes through the exhaust channel and is in direct contact with the liquid discharge device 23, the liquid discharge device 23 is actively fused, cooling fluid is discharged from the fused part, and the thermal runaway battery core is subjected to spray cooling.

Referring to fig. 1, the battery module further includes a module fixing member 5 for accommodating the battery cell 1. Electric core 1 arranges in proper order in module mounting 5. The conductive medium 3 is arranged at the top of the battery cell 1 and electrically connects the battery cell 1. The upper part of the conductive medium 3 is sequentially provided with a signal acquisition device 4 and a fire extinguishing insulation device 2.

Example two

The second embodiment is a further improvement on the basis of the first embodiment, and the specific difference between the second embodiment and the first embodiment is the structure of the liquid discharge device 23.

Referring to fig. 6 and 7, the drainage device 23 includes a tubular body 231 and a liquid storage chamber 232 disposed at a middle section of the tubular body 231. The cross-sectional area of the reservoir cavity 232 is greater than the cross-sectional area of the tubular body 231 in a direction perpendicular to the flow of the cooling fluid. The arrangement can store more cooling fluid on one hand, and ensures that the sufficient cooling fluid can spray the thermal runaway cell after the drainage device 23 is melted by the gas exhausted by the exhaust valve 11; on the other hand, the contact area between the liquid discharge device 23 and the gas discharged from the gas discharge valve 11 can be increased, so that a more effective fire extinguishing effect is realized, and the safety and stability of the battery module are improved.

It should be further noted that, in this embodiment, a surface of the liquid storage cavity 232 facing the exhaust valve 11 is formed to be concave towards a direction away from the exhaust valve 11, referring to fig. 7, a surface of the liquid storage cavity 232 facing the exhaust valve 11 is a bottom surface 233 of the liquid storage cavity, and a cross section of the bottom surface 233 along the radial direction is arc-shaped. The bottom surface of indent structure can further gather together by 11 combustion gas of discharge valve like this, ensures to fuse in preset position, further improves the fire control effect, improves battery module's safety and stability nature.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply 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 limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The term "communicate" is also to be understood broadly, i.e., may be direct or indirect via an intermediary. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

"plurality" in the present disclosure and appended claims refers to two or more than two unless otherwise indicated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed battery pack without departing from the spirit or scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A battery module, comprising:

the battery comprises battery cells, a plurality of battery cells and a plurality of exhaust valves, wherein the battery cells are arranged and provided with the exhaust valves;

the fire extinguishing device comprises a liquid discharging device used for cooling fluid circulation, the liquid discharging device comprises a normal state and a liquid discharging state, and when the liquid discharging state is reached, the cooling fluid flows out of the liquid discharging device to cool the battery core;

the fire extinguishing device further comprises a fire extinguishing device body (26), the fire extinguishing device body (26) is formed into an upper cover of the battery module, a first heat conducting hole (22) is formed in the fire extinguishing device body, and the first heat conducting hole (22) is arranged opposite to the exhaust valve and used for guiding gas exhausted from the exhaust valve; the liquid drainage device (23) is arranged in the first heat conduction hole (22);

a signal acquisition device is further arranged between the fire extinguishing device body (26) and the battery cell, a second heat conduction hole and a thermal runaway monitoring device are arranged on the signal acquisition device, the second heat conduction hole (41) is arranged right opposite to the exhaust valve, and the thermal runaway monitoring device is arranged in the second heat conduction hole (41);

the first heat conduction hole (22) and the second heat conduction hole (41) jointly form an exhaust channel for exhausting the gas out of the battery module.

2. The battery module of claim 1, wherein the drain is a low melt drain.

3. The battery module according to claim 2, wherein a flow passage is provided in the fire extinguishing device, and the flow passage connects the plurality of liquid discharge devices in series.

4. The battery module according to claim 2, wherein the fire extinguishing device is provided with a flow passage that connects the plurality of liquid discharge devices in parallel.

5. The battery module according to claim 2, wherein the drain is in the shape of a tubular structure.

6. The battery module of claim 2, wherein the drain comprises a tubular body and a reservoir disposed at a middle section of the tubular body.

7. The battery module according to claim 6, wherein the surface of the reservoir facing the exhaust valve is formed with a concave structure facing away from the exhaust valve.

8. The battery module according to claim 1, wherein the thermal runaway monitoring device comprises a smoke sensor and/or a light sensor.

9. The battery module of claim 8, wherein the thermal runaway monitoring device is integrated with the signal acquisition device.

10. The battery module according to claim 1, wherein the thermal runaway monitoring device (42) is at right angles to the projection of the drainage device (23) in the horizontal direction.