CN216213676U

CN216213676U - Box, battery package and vehicle under battery package

Info

Publication number: CN216213676U
Application number: CN202121452058.1U
Authority: CN
Inventors: 曹永强; 梁宏伟; 刘崇威; 李岩
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2022-04-05
Anticipated expiration: 2031-06-28
Also published as: DE202021107077U1

Abstract

The utility model provides a box, battery package and vehicle under battery package, the box includes boundary beam frame, end backplate and inside crossbeam under the battery package, and the boundary beam frame has inlet port, exhaust passage and exhaust hole, and the inlet port passes through exhaust passage and exhaust hole intercommunication, and the exhaust hole is used for flowing the gas fire stream in exhaust hole via exhaust passage and discharges down the box main part, and inside crossbeam is fluted and/or is provided with the breach at the tip, the recess with the breach makes adjacent battery hold the chamber intercommunication. This box under battery package can reduce that certain battery holds the local high temperature of intracavity and causes destruction or certain battery local high temperature to cause the thermal runaway diffusion to the box, prevents to explode after the battery thermal runaway.

Description

Box, battery package and vehicle under battery package

Technical Field

The disclosure relates to the technical field of batteries, in particular to a battery pack lower box body, a battery pack and a vehicle.

Background

With the planning and support of the country on the development of new energy automobile industry, electric automobiles are more and more popular, but the safety of batteries becomes an industry pain point. The cumulative occurrence of thermal runaway of an electric automobile battery from 2019 to 2020 has caused more than a hundred cases of vehicle fire accidents. The national release of the strong standard GB 38031 and 2020 Power storage Battery safety requirement for electric vehicles in 2020, the standard clearly requires that the battery pack should provide alarm and protection 5min before the danger of the passenger compartment caused by the thermal runaway of a single battery, and the thermal runaway of the battery pack does not cause fire and does not explode, thereby solving the problems of pain and difficulty in the industry.

SUMMERY OF THE UTILITY MODEL

In view of this, the present disclosure is directed to a battery pack and a lower case, which adopt a current conversion heat dissipation design, so as to achieve the balance between the internal pressure and the temperature of the battery pack, and reduce the temperature of the directional explosion venting fire inlet through the "uniform" and "dissipation" of heat. The lower box body can improve the use safety of the battery pack and reduce the risk of explosion and fire caused by thermal runaway of the battery pack.

In order to achieve the purpose, the technical scheme of the disclosure is realized as follows:

the utility model provides a box under battery package, including lower box main part, lower box main part includes boundary beam frame, end backplate and inside crossbeam, through inside crossbeam will a plurality of batteries that are used for holding the battery module are separated into to box main part down and are held the chamber, boundary beam frame has inlet port, exhaust passage and exhaust hole, the inlet port passes through exhaust passage with the exhaust hole intercommunication, the inlet port is used for introducing exhaust passage with the gas fire stream that produces when battery module thermal runaway, the exhaust hole is used for with the via exhaust passage flows to the gas fire stream in exhaust hole discharges lower box main part, inside crossbeam is equipped with the recess and/or is provided with the breach at the tip, the recess with the breach makes adjacent battery hold the chamber intercommunication.

Further, the notch is located at an upper portion of an end of the inner beam.

Furthermore, a plurality of mounting points are arranged on the inner cross beam and used for being connected with an upper cover of the battery pack, and the grooves and the mounting points are arranged at intervals.

Further, the battery module in the battery accommodation cavity comprises the protective cover, and the lower edge of the groove is higher than the height of the protective cover of the battery module.

Further, the opening areas of the grooves are gradually reduced from the two ends of the inner cross beam to the middle.

Further, a liquid cooling plate is arranged at the bottom of the battery module and integrated inside the lower box body, a current conversion heat dissipation channel formed between the liquid cooling plate and the bottom protection plate is communicated with the exhaust channel, a plurality of concave parts are formed at the end part of the liquid cooling plate, and the current conversion heat dissipation channel capable of achieving gas exchange is formed between the upper space of the liquid cooling plate and the lower space of the liquid cooling plate.

Further, the bottom of the battery module is provided with a liquid cooling plate, the liquid cooling plate is integrated in the lower box body, the liquid cooling plate is communicated with a current conversion heat dissipation channel formed between the bottom protection plates and the exhaust channel, a through hole is formed in the middle face of the liquid cooling plate, and the current conversion heat dissipation channel capable of achieving gas exchange is formed in the upper space of the liquid cooling plate and the lower space of the liquid cooling plate.

Further, the through holes of the liquid cooling plate are located at the center line position of the liquid cooling plate.

Further, the through hole of the liquid cooling plate is oval.

The present disclosure also provides a battery pack using the battery pack lower box body.

The present disclosure also provides a vehicle using the battery pack.

Compared with the prior art, the lower box body of the battery pack has the following advantages:

the battery pack adopt the design of a current conversion heat dissipation structure, all be equipped with current conversion heat dissipation channel at liquid cooling board bottom and module top, and 360 surround the module in ZY direction current conversion heat dissipation channel, carry out heat balance and scatter and disappear to the module, in XY direction, current conversion heat dissipation channel and a plurality of battery hold the chamber and communicate, further balance the heat, reduce pressure and temperature that thermal runaway module battery held the intracavity, reduce directional row through thermal "all" scatter "and explode into fire door temperature. Compared with the prior art, the battery pack has higher and more guaranteed safety, and the risk of fire caused by thermal runaway explosion of the battery pack is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure. In the drawings:

fig. 1 is an exploded view of a battery pack according to an embodiment of the present disclosure;

fig. 2 is a schematic view of a lower case of a battery pack according to an embodiment of the present disclosure;

FIG. 3 is a schematic cross-sectional Y-direction view of an edge beam according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of a rocker intake aperture according to an embodiment of the disclosure;

FIG. 5 is an enlarged view of a portion of FIG. 2 at A;

FIG. 6 is an enlarged view of a portion of FIG. 2 at B;

FIG. 7 is an enlarged view of a portion of FIG. 2 at C;

fig. 8 is a schematic view of a Y-section of a battery pack according to an embodiment of the present disclosure;

FIG. 9 is an enlarged view of a portion of FIG. 8 at F;

fig. 10 is a schematic diagram of a commutation path according to an embodiment of the present disclosure.

Description of reference numerals:

a lower box body 1 of the battery pack; a battery module 2; high-low voltage electrical components 3; an upper cover 4; a main exhaust device 5; a sub-exhaust device 6; a lower case main body 100; an edge frame 10; side beams 11, end beams 12; the bulge edge beam 13; a lug beam 14; an inner cross member 15; a bottom guard plate 16; a liquid-cooling plate 17; an intake hole 111; an exhaust passage 112; mounting points 151; a groove 152; a cell monomer 211; an insulating material 212; a bus bar 213; a protective cover 22;

commutation channels

101, 102, 103, 104, 105, 106

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the present disclosure more clearly understood, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the present disclosure and are not intended to limit the present disclosure, as embodiments and features of embodiments in the present disclosure may be combined with each other without conflict.

It should be noted that the term "front" in the present disclosure refers to a direction from the tail of the vehicle to the head of the vehicle, and vice versa, the front-back direction is parallel to the X-axis; the term "up" refers to the direction from the bottom of the vehicle to the top of the vehicle, and vice versa, the up-down direction being parallel to the Z-axis. In addition, the references in the present disclosure to be parallel to the X axis (X direction), the Z axis (Z direction), and the Y axis (Y direction) may be completely parallel to the X axis (X direction), the Z axis (Z direction), and the Y axis (Y direction), or may be substantially parallel to the X axis (X direction), the Z axis (Z direction), and the Y axis (Y direction); descriptions about the perpendicular to the X axis (X direction), the Z axis (Z direction) and the Y axis (Y direction) are similar to the descriptions about the parallel directions, and are not repeated herein; the descriptions along the X axis (X direction), the Z axis (Z direction) and the Y axis (Y direction) are similar to the descriptions parallel to the above, and are not repeated herein.

The present disclosure will be described in detail below with reference to the accompanying drawings 1 to 10 in conjunction with embodiments.

Referring to fig. 1, the present disclosure provides a battery pack lower case 1 and a battery pack having the same, and the battery pack mainly includes a battery pack lower case 1, a battery module 2, high and low voltage electrical components 3, and an upper cover 4.

Box 1 sealing connection under upper cover 4 and the battery package, a plurality of battery module 2 hold in the accommodation space that box 1 formed after connecting under upper cover 4 and the battery package, and battery module 2 includes a plurality of electric core monomers 211 and protection casing 22, is equipped with explosion-proof mouthful on the protection casing 22. The upper cover 4 is preferably formed by adopting a high-strength and high-temperature-resistant material stamping process, so that the upper cover is prevented from losing efficacy in advance when the battery is out of control due to heat, and harmful gas or flame is prevented from being sprayed upwards to enter a cabin to cause personal safety accidents.

As shown in fig. 2, the lower case 1 of the battery pack includes a lower case body 100, the lower case body 100 includes an edge beam frame 10, a floor shield 16, and an inner cross member 15, and the edge beam frame 10 includes an edge beam 11 and an end cross member 12. In some embodiments, the upper cover 4 and the lower case 1 are formed with protruding portions in a top view, the protruding portions of the upper cover 4 and the lower case 1 cooperate with each other to form a receiving space for receiving the high-low voltage electrical component 3, and the edge beam frame 10 includes an edge beam 11, an end beam 12, a protruding portion edge beam 13, and a protruding portion beam 14.

The internal beam 15 divides the boundary beam frame 10 into a plurality of battery holding cavities for arranging the battery modules 2 and other components, the battery holding cavities can be designed in an expanded mode according to actual needs, the number and the size of the battery holding cavities can be adjusted according to actual projects, and one, two or more battery modules 2 can be arranged in one independent battery holding cavity. The internal beam 15 plays a physical isolation role between each battery holding cavity, and if thermal runaway occurs in the single battery holding cavity, the phenomenon that the thermal runaway diffusion is spread due to serious streaming formed by the gas and fire flow generated after the thermal runaway in the battery pack can be avoided.

In some embodiments, as shown in fig. 9, the battery module 2 is formed by stacking a plurality of battery cells 211 and a plurality of high temperature resistant impact resistant heat insulating materials 212, the top of the battery module includes a bus bar 213 and a cell collecting component, the bus bar 213 is connected with an output pole of the battery cell 211 by a laser welding process, the battery cell 211 includes an explosion-proof valve (not shown in the figure) for pressure relief after thermal runaway of the battery cell 211, the protective cover 22 is provided with an explosion vent, and the explosion vent is opposite to the explosion-proof valve, and is used for outward discharge of gas and fire flow generated by the thermal runaway battery, so as to reduce residual temperature of the thermal runaway.

The boundary beam frames 10 are all of a hollow cavity structure, and a sealed and continuous exhaust passage is formed by splicing the boundary beam frames 10, and the exhaust passage can be divided into one layer or multiple layers in the cavity of the boundary beam frame 10 according to the Z direction. In some embodiments, the hollow cavity of the side sill frame 10 is provided with a reinforcing rib, so that different numbers of exhaust passages can be realized, and the exhaust passages with different numbers and cross-sectional shapes are considered in the present disclosure, such as a section shaped like a Chinese character 'ri', a section shaped like a Chinese character 'tian', and the present disclosure takes three exhaust passages shaped like a Chinese character 'mu' as an example for explanation, and as shown in fig. 3, the side sill 11 is divided into a top exhaust passage 112a, a middle exhaust passage 112b, and a bottom exhaust passage 112 c.

In some embodiments, as shown in fig. 4, the side frame 11 and the battery compartment side are provided with a plurality of air inlet holes 111, the air inlet holes 111 are communicated with the air exhaust channel 112, and different numbers and shapes of air exhaust channels are all considered within the scope of the present disclosure. In some embodiments, to achieve the distribution of the heat flow of the gas-fire flow, the gas inlet holes 111 may be divided into multiple layers in the Z direction, and the number of the gas outlet holes 111 is greater than or equal to the number of the gas outlet channels 112, i.e., each gas outlet channel 112 has at least one layer of gas inlet holes 111. Taking three exhaust passages in a zigzag pattern as an example, as shown in fig. 4, the top layer exhaust holes 111a communicate with the top layer exhaust passage 112a, the intermediate layer exhaust holes 111b communicate with the intermediate layer exhaust passage 112b, and the bottom layer exhaust holes 111 communicate with the bottom layer exhaust passage 112 c.

In some embodiments, the design of the air inlet holes 111 is not limited to the circular structure illustrated in the present disclosure, and may be a long circle, a quadrangle, a hexagon, an octagon, etc., and the positions of the air outlet holes 111 are uniformly arranged according to the principle of flow uniform distribution, so as to prevent the occurrence of an air outlet dead zone.

In some embodiments, the top layer air inlet holes 111a corresponding to the top layer air exhaust channel 112a closest to the upper cover 4 are designed to be small holes, the number of the top layer air inlet holes 111a corresponding to each battery accommodating cavity is not less than two, so as to prevent the boundary beam frame 10 from being damaged by impact when a certain battery module 2 is in thermal runaway, the number of the air inlet holes 111a is not limited to two in the disclosure, the illustration is merely an illustration, and more air inlet holes can be provided. For different design forms of the battery module 2, each layer of the air inlets 111 can be designed to be a plurality of air inlets 111a, but the number of the air inlets 111a connected with the top layer exhaust channel 112a is at least not less than the number of the air inlets 111 connected with each lower exhaust channel 112.

In some embodiments, to equalize the flow rate of the air intake holes 111 and achieve the effect of rapid dissipation, the opening area of the middle air intake hole 111b is larger than that of the bottom air intake hole 111c, and the opening area of the bottom air intake hole 111c is larger than that of the top air intake hole 111 a.

In some embodiments, the exhaust channel and the intake hole are disposed inside the inner beam 15, and the exhaust channel of the inner beam 15 is communicated with the exhaust channel of the side beam 11, and the intake hole is not limited to be disposed only on the side beam as illustrated in the present disclosure, and may be disposed on the end beam 12.

The boundary beam frame 10 is provided with exhaust holes at the position communicated with the outside, the gas and fire flow generated by the thermal runaway of the battery module 2 can be exhausted through each exhaust channel through the exhaust holes, and one or more exhaust holes can be selectively arranged on the boundary beam frame 10. The present disclosure is illustrated with the end cross member 12 and the lip side member 14 incorporating exhaust vents, as shown in fig. 2.

In some embodiments, as shown in fig. 1, it is preferable that a vent is provided on the vent hole, and the vent is opened only under a certain pressure, so that the high-temperature and high-pressure fire stream in the vent channel is rapidly discharged from the vent to the space outside the battery pack. Preferably, exhaust apparatus uses explosion-proof valve, and under normal operating mode, explosion-proof valve can play dustproof waterproof and balanced battery package inside and outside pressure's effect.

In some embodiments, as shown in fig. 2, when a plurality of exhaust devices are selectively arranged, the plurality of exhaust devices can be divided into a main exhaust device 5 and an auxiliary exhaust device 6, the starting pressure threshold of the main exhaust device 5 is lower than the starting pressure threshold of the auxiliary exhaust device 6, when a certain battery module 2 is out of control due to thermal runaway, the generated fire flows enter corresponding exhaust channels 112 along the air inlet holes 111 on both sides of the accommodating cavity of the battery module 2, and reach the position of the main exhaust device 5 through the continuous exhaust channels 112 of the side frame 10, and the main exhaust device 5 is started when reaching the pressure threshold thereof, so as to form a smooth channel to discharge the fire flows out of the battery pack, thereby achieving the purpose of rapid pressure relief. If higher pressure is generated in the battery pack instantly, the maximum pressure relief capacity of the main exhaust device 5 is exceeded, when the raised pressure reaches the pressure threshold of the auxiliary exhaust device 6, the auxiliary exhaust device 6 is started to quickly relieve the pressure, and the battery pack is prevented from being ignited and exploded. Different placement positions of the main exhaust 5 and the auxiliary exhaust 6 are contemplated by the present disclosure. Preferably, the main exhaust device 5 is provided on the end cross member 12, and the sub exhaust device 6 is provided on the side member 11 and/or the lip side member 13. Preferably, the opening area of the corresponding exhaust hole of the main exhaust device 5 is larger than or equal to the opening area of the corresponding exhaust hole of the auxiliary exhaust device 6.

In some embodiments, as shown in fig. 5, the inner beam 15 is provided with a plurality of mounting points 151 and a plurality of grooves 152, preferably, the grooves 152 are spaced from the mounting points 151, and the mounting points 151 are used for connecting with the upper cover 4, so that the mode of the battery pack can be improved. The groove 152 and the upper cover 4 form a current conversion heat dissipation channel 106 capable of realizing gas exchange of adjacent battery accommodation cavities, and the lower edge of the groove 152 is higher than the protective cover 22 of the battery module 2, so that eruptions are prevented from being directly sprayed to the battery module 2 when the battery is in thermal runaway, and thermal runaway diffusion is avoided.

In some embodiments, as shown in fig. 6, the two end portions of the inner cross beam 15 are provided with notches, and a through space is formed between the inner cross beam and the edge beam 11 for connecting a high-voltage bus bar, the high-voltage bus bar is protected by an insulating high-temperature-resistant material to prevent insulation failure after thermal runaway of the battery, and when the thermal runaway occurs, the through space forms a commutation heat dissipation channel 102 capable of realizing gas exchange between adjacent battery receiving cavities. Preferably, as shown in fig. 7, a middle groove is arranged in the middle of the inner beam 15, and the groove and the upper cover 4 form a passing space for accommodating a low-voltage wire, and the low-voltage wire is also protected by an insulating high-temperature-resistant material to prevent high-temperature insulation failure, and the passing space forms a commutation heat dissipation channel 104 when thermal runaway occurs. The commutation heat dissipation channel 106 formed by the notch and the commutation heat dissipation channel 104 formed by the middle groove play a role in commutation heat dissipation when the battery is out of control due to heat, and are used for dissipating gas-fire flow inside a certain battery accommodating cavity and balancing the temperature inside the battery pack.

In some embodiments, as shown in fig. 8, the battery module 2 is provided at the bottom thereof with a liquid cooling plate 17, and the liquid cooling plate 17 is integrated inside the lower case 3. In some embodiments, the end of the liquid cooling plate 17 is formed with a plurality of concave portions, and after the liquid cooling plate 17 is mounted, a through hole is formed with the inner side surface of the side beam 11, so as to form a heat exchanging and dissipating passage 101 for exchanging gas between the upper space of the liquid cooling plate 17 and the lower space of the liquid cooling plate 17. In some embodiments, the liquid cooling plate 17 has a through hole formed in the middle thereof, and a commutating heat dissipation channel 103 is formed in the upper space of the liquid cooling plate 17 for gas exchange with the lower space of the liquid cooling plate 17. Preferably, the through holes of the liquid-cooled plate 17 are located at the centerline of said liquid-cooled plate 17. Preferably, the through-holes of the liquid cooling plate 17 are oblong. The bottom of the liquid cooling plate 17 is provided with a bottom guard plate 16, a commutation heat dissipation channel 105 is formed between the bottom guard plate 16 and the liquid cooling plate 17, and the commutation heat dissipation channel 105 is communicated with the commutation

heat dissipation channels

101 and 103 and is also communicated with the exhaust channel of the side beam 11, so that the exhaust channel 112 of the side beam 11 on the opposite side is communicated with the commutation heat dissipation channel 105.

Fig. 10 shows the current conversion path in the battery pack, when a certain electric core monomer 211 in the battery module 2 is out of control thermally, a violent chemical reaction occurs inside the electric core monomer 211, a large amount of heat is generated instantaneously, and the explosion-proof opening has the functions of guiding and evacuating along with the gas-fire current belt pressure eruption, so that the heat is dissipated quickly, and the eruption is prevented from being accumulated inside the battery module 2. The erupted gas fire flow is evacuated at the top of the battery module 2 through the commutation

heat dissipation channels

102, 104 and 106 to carry out the commutation heat dissipation in the X direction, and the commutation paths are a 1-a 5 shown in fig. 8; meanwhile, the commutation heat dissipation is carried out along the Z direction at the two sides and the middle of the battery module 2 through the commutation

heat dissipation channels

101 and 103, and the commutation paths are b 1-b 3 shown in FIG. 10; and meanwhile, the commutation heat dissipation is carried out at the bottom of the battery module 2 along the Y direction through the commutation heat dissipation channel 105, the commutation path is as shown in c 1-c 2 in fig. 10, and the gas and fire flow enters the exhaust channel in the boundary beam frame 10 after being evacuated in too many directions and then is exhausted out of the lower box body of the battery pack through the exhaust hole.

Through the heat dissipation design of change of current, the high temperature gas stream that produces after certain electric core monomer 211 thermal runaway of battery package is dispersed to a plurality of batteries and holds the chamber, and the directional row of exhaust hole realization is exploded on rethread boundary beam frame 10, and the heat dissipation design of change of current not only can the balanced battery package internal temperature, can also reduce the destruction that certain battery holds the intracavity local temperature too high and lead to the fact the box, prevents that certain battery from holding the too high thermal runaway diffusion that causes of chamber local temperature.

According to the battery pack of the second aspect embodiment of this disclosure, including: the battery lower case 1 in the above embodiment.

According to a third aspect embodiment of the present disclosure, a vehicle includes: the battery pack in the above embodiment.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. The lower box body of the battery pack comprises a lower box body main body (100) and is characterized in that the lower box body main body (100) comprises a boundary beam frame (10), a bottom protection plate (16) and an inner cross beam (15), the lower box body main body (100) is divided into a plurality of battery accommodating cavities for accommodating battery modules (2) through the inner cross beam (15), the boundary beam frame (10) is provided with an air inlet hole (111), an exhaust channel (112) and an exhaust hole, the air inlet hole (111) is communicated with the exhaust hole through the exhaust channel (112), the air inlet hole (111) is used for introducing air fire flow generated when the battery modules (2) are in thermal runaway into the exhaust channel (112), the exhaust hole is used for exhausting the air fire flow flowing to the exhaust hole through the exhaust channel (112) out of the lower box body main body (100), the inner cross beam (15) is provided with a groove and/or a notch at the end part, the groove and the notch enable adjacent battery accommodating cavities to be communicated.

2. The lower case for battery packs as claimed in claim 1, wherein the notch is located at an upper portion of the end of the inner cross member (15).

3. The lower box body of the battery pack as claimed in claim 1, wherein the inner cross beam (15) is provided with a plurality of mounting points (151), the mounting points (151) are used for being connected with an upper cover (4) of the battery pack, and the grooves (152) are arranged at intervals with the mounting points (151).

4. The battery pack lower case according to claim 3, wherein the battery module (2) in the battery receiving cavity includes a protective cover (22), and a lower edge of the groove (152) is higher than a height of the protective cover (22) of the battery module (2).

5. The lower case for battery packs as claimed in claim 3, wherein the open area of the plurality of grooves (152) is gradually reduced from both ends of the inner cross member (15) toward the middle.

6. The lower box body of the battery pack according to claim 1, wherein a liquid cooling plate (17) is arranged at the bottom of the battery module (2), the liquid cooling plate (17) is integrated inside the lower box body (100), a commutation heat dissipation channel (105) formed between the liquid cooling plate (17) and the bottom protection plate (16) is communicated with the exhaust channel, a plurality of concave parts are formed at the end part of the liquid cooling plate (17), and a commutation heat dissipation channel (101) capable of realizing gas exchange is formed in the upper space of the liquid cooling plate (17) and the lower space of the liquid cooling plate (17).

7. The lower box body of the battery pack according to claim 1, wherein a liquid cooling plate (17) is arranged at the bottom of the battery module (2), the liquid cooling plate (17) is integrated inside the lower box body (100), a commutation heat dissipation channel (105) formed between the liquid cooling plate (17) and the bottom protection plate (16) is communicated with the exhaust channel, a through hole is formed in the middle of the liquid cooling plate (17), and a commutation heat dissipation channel (103) capable of realizing gas exchange is formed in the upper space of the liquid cooling plate (17) and the lower space of the liquid cooling plate (17).

8. The lower case for battery packs as claimed in claim 7, wherein the through holes of the liquid cooling plate (17) are located at the center line of the liquid cooling plate (17).

9. The lower case of battery pack according to claim 8, wherein the through hole of the liquid cooling plate (17) is oblong.

10. A battery pack, characterized by comprising the battery pack lower case (1) according to any one of claims 1 to 9 and a battery module (2) disposed in the battery receiving cavity.

11. A vehicle characterized by comprising the battery pack according to claim 10.