CN116435692A

CN116435692A - Lithium battery system and electric automobile

Info

Publication number: CN116435692A
Application number: CN202310629602.2A
Authority: CN
Inventors: 赵琼; 赵欢欢; 宋开通; 张伟; 朱建锦
Original assignee: Chery New Energy Automobile Co Ltd
Current assignee: Chery New Energy Automobile Co Ltd
Priority date: 2023-05-30
Filing date: 2023-05-30
Publication date: 2023-07-14

Abstract

The application relates to a lithium battery system and an electric automobile, and belongs to the technical field of batteries. The lithium battery system comprises a shell, a plurality of battery monomers and a fire extinguishing assembly; the inside of the shell is provided with a cavity; the battery units are positioned in the cavity and connected with the inner wall of the shell, wherein a gap is reserved between two adjacent battery units; the fire extinguishing assembly is located in the cavity and connected with the inner wall of the shell, and the fire extinguishing assembly is used for: containing a fire extinguishing medium; and when the temperature in the cavity is greater than a preset reference temperature, spraying the fire extinguishing medium into the cavity. By adopting the application, the lithium battery system can be effectively prevented from thermal runaway.

Description

Lithium battery system and electric automobile

Technical Field

The application relates to the technical field of batteries, in particular to a lithium battery system and an electric automobile.

Background

At present, the lithium ion battery is widely applied to electric automobiles due to the advantage of high energy density. Lithium battery systems are typically composed of a plurality of battery cells, each of which includes a positive and negative electrode, a separator, an electrolyte, an insulating layer, and a case.

At present, the electrolyte of the lithium battery is usually an organic solvent with very low ignition point, and is easy to burn. If the insulating layer of one battery cell breaks to cause electrolyte leakage, the battery cell is likely to fire, other battery cells are ignited, and thermal runaway of the lithium battery system occurs to cause casualties.

Therefore, there is a need for a lithium battery system that can effectively prevent thermal runaway from occurring.

Disclosure of Invention

The embodiment of the application provides a lithium battery system and an electric automobile, which can solve the technical problems in the related art, and the technical scheme is as follows:

in a first aspect, embodiments of the present application provide a lithium battery system applied to an electric vehicle, the lithium battery system including a housing, a plurality of battery cells, and a fire suppression assembly;

the inside of the shell is provided with a cavity;

the battery units are positioned in the cavity and connected with the inner wall of the shell, wherein a gap is reserved between two adjacent battery units;

the fire extinguishing assembly is located in the cavity and connected with the inner wall of the shell, and the fire extinguishing assembly is used for:

containing a fire extinguishing medium;

and when the temperature in the cavity is greater than a preset reference temperature, spraying the fire extinguishing medium into the cavity.

In one possible implementation, the plurality of battery cells are distributed in a matrix.

In one possible implementation, the plurality of battery cells includes a first battery cell and a second battery cell, wherein the first battery cell and the second battery cell are two battery cells of the plurality of battery cells that are furthest apart;

the fire extinguishing assembly comprises a first accommodating component, wherein the first accommodating component is positioned in the cavity, is positioned on one side, away from the second battery unit, of the first battery unit, and is connected with the inner wall of the shell.

In one possible implementation, the fire extinguishing assembly further comprises a second receiving member located in the cavity on a side of the second cell remote from the first cell and connected to the inner wall of the housing, the second receiving member having an opening facing opposite to the first receiving member opening, the first receiving member and the second receiving member each being configured to:

containing a fire extinguishing medium;

In one possible implementation manner, the first accommodating component comprises a first tank body and a temperature control valve, the first tank body is used for accommodating high-pressure fire extinguishing medium, the first tank body is provided with a first opening, one end of the temperature control valve is communicated with the first opening, the other end of the temperature control valve is communicated with the cavity, and the temperature control valve is used for being in an opening state when the temperature in the cavity is greater than a preset reference temperature.

In one possible implementation, the fire suppression assembly further comprises a temperature sensor and a controller, the first housing assembly comprising a first canister and an electrically controlled valve;

the first tank body is used for containing high-pressure fire extinguishing medium and is provided with a first opening, one end of the electric control valve is communicated with the first opening, and the other end of the electric control valve is communicated with the cavity;

the temperature sensor is used for detecting the temperature in the cavity;

and the controller is used for controlling the electric control valve to be in an opening state when the temperature in the cavity is greater than the preset reference temperature.

In one possible implementation, the housing has a vent;

the lithium battery system further includes a first conduit and a second conduit;

the first pipeline is positioned in the cavity, the outer wall of the first pipeline is attached to the battery units, one end of the first pipeline is provided with a second opening, the second opening is communicated with the other end of the electric control valve, the first pipeline is provided with a plurality of first through holes penetrating through the pipeline wall, and each first through hole is correspondingly communicated with one gap;

the second pipeline is located in the cavity and located on one side, away from the first pipeline, of the plurality of battery monomers, the outer wall of the second pipeline is attached to the plurality of battery monomers, one end of the second pipeline is provided with a third opening, the third opening is communicated with the exhaust hole, the second pipeline is provided with a plurality of second through holes penetrating through the pipeline wall, and each second through hole is correspondingly communicated with one gap.

In one possible implementation, the lithium battery system further includes a vent fan located in the vent hole and connected to an inner wall of the vent hole.

In one possible implementation, the extinguishing medium is carbon dioxide gas.

In a second aspect, embodiments of the present application provide an electric vehicle, which includes the lithium battery system in the first aspect and its possible implementation manners.

The technical scheme provided by the embodiment of the application at least comprises the following beneficial effects:

the embodiment of the application provides a lithium battery system, this lithium battery system has casing, battery monomer and fire extinguishing component, and battery monomer and fire extinguishing component are arranged in the cavity of casing for hold fire extinguishing medium, and when the temperature in the cavity is greater than predetermine the reference temperature, spray fire extinguishing medium to the cavity in. Like this, when the battery monomer takes place the fire burning, when the temperature in the cavity risees more than predetermineeing the reference temperature, fire extinguishing component can spray the fire extinguishing medium to the cavity in put out a fire, and then effectively prevent that lithium battery system from taking place thermal runaway.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 2 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 3 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 4 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 5 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 6 is a schematic structural view of a lithium battery system according to an embodiment of the present application;

fig. 7 is a schematic diagram of a lithium battery system according to an embodiment of the present application.

Description of the drawings

1. A housing;

1a, cavity; 1b, exhaust holes;

2. a battery cell;

21. a first battery cell; 22. a second battery cell;

3. a fire suppression assembly;

31. a first receiving member; 32. a second receiving member; 33. a temperature sensor; 34. a controller;

311. a first tank; 312. a temperature control valve; 313. an electric control valve;

311a, a first opening;

4. a first pipe; 4a, a second opening; 4b, a first through hole;

5. a second pipe; 5a, a third opening; 5b, a second through hole;

6. an exhaust fan;

7. a connecting plate; 7a, connecting through holes.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," "third," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are present in front of "comprising" or "comprising" are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to denote relative positional relationships, which may also change accordingly when the absolute position of the object to be described changes.

With the development of new energy technology, more and more users select electric automobiles. Lithium batteries are the mainstay of choice due to their high energy density. At present, an electrolyte of a lithium battery is usually an organic solvent with a very low ignition point, and is easy to burn, so how to solve the problem of thermal runaway is a primary problem of an electric automobile. Currently, there are two paths for solving thermal runaway, one is to use electrolyte which is not easy to burn, and the other is to organize burning in time when the battery burns, and the latter is currently the important research in the industry.

The embodiment of the application provides a lithium battery system, as shown in fig. 1, which comprises a shell 1, a plurality of battery cells 2 and a fire extinguishing assembly 3. By adopting the application, the fire extinguishing assembly 3 can be used for flame retardance when the battery monomer 2 starts to burn, so that thermal runaway is rapidly solved.

Fig. 1 is a schematic diagram of a lithium battery system according to an embodiment of the present application, and a housing 1 has a cavity 1a therein. The battery cells 2 are all located in the cavity 1a and are connected with the inner wall of the shell 1, and a gap is reserved between two adjacent battery cells 2. The fire extinguishing assembly 3 is arranged in the cavity and is used for containing fire extinguishing medium, and when the temperature in the cavity 1a is greater than a preset reference temperature, the fire extinguishing medium is sprayed into the cavity 1a.

Thus, when the temperature in the cavity 1a is greater than the preset reference temperature, the fire extinguishing assembly 3 is controlled to spray fire extinguishing medium to extinguish fire, so that thermal runaway is solved.

The following describes each part of the lithium battery system:

1. shell 1

The housing 1 is a component of a lithium battery system for housing a battery cell 2 and a fire suppression assembly 3.

As shown in fig. 1, the housing 1 has a cubic structure with a cavity 1a inside.

Alternatively, the shape of the outer wall and the shape of the inner wall of the housing 1 may both be hexahedral shapes.

In practice, the housing 1 may be constructed from a plurality of metal plates that are spliced.

In this way, the difficulty of processing the housing 1 can be reduced.

The material of the casing 1 may be a metal material such as a galvanized plate or an aluminum plate, or may be a polymer material such as high-temperature nylon, which is not limited in this embodiment of the present application.

2. Battery cell 2

The battery cell 2 is a component for supplying power in a lithium battery system.

As shown in fig. 1, the lithium battery system includes a plurality of battery cells 2, and the plurality of battery cells 2 are all located inside a cavity 1a.

The battery cells 2 may have a cubic structure and are connected to the inside of the case 1 with a gap between adjacent two battery cells 2.

Alternatively, the plurality of battery cells 2 may be distributed in a matrix.

As shown in fig. 2, a plurality of battery cells 2 are distributed in a row matrix with a gap between adjacent two battery cells 2.

In practice, the top surface of the battery cell 2 may be connected to the top surface of the cavity 1a, and the bottom surface of the battery cell 2 may be connected to the bottom surface of the cavity 1a. The battery cells 2 may be all perpendicular to the bottom surface of the cavity 1a.

The connection mode between the battery cell 2 and the housing 1 may be welding or bonding, and the connection mode between the battery cell 2 and the housing 1 is not limited in the embodiment of the present application.

Referring to fig. 2, adjacent two battery cells 2 are parallel with a gap.

Like this, when the burning takes place for arbitrary battery monomer 2, the regional atmospheric pressure of burning reduces, and fire extinguishing medium can carry to the burning region through the clearance fast under the atmospheric pressure effect to each battery monomer 2 of cladding, fire-retardant to the battery monomer that has taken place the burning, and protect the battery monomer that has not taken place the burning yet, realize the thermal control to lithium battery system.

In the lithium battery system in the M-direction head-up view of fig. 2, the width of the battery cells 2 may be a first value L1, the width of the gap between two adjacent battery cells 2 may be a second value L2, and the relationship l2=0.2l1 may be satisfied between the second value L2 and the first value L1.

Therefore, the size of the gap is moderate, so that the fire extinguishing medium can be quickly conveyed to the burning position, and the arrangement of the plurality of battery cells 2 is compact, thereby being beneficial to the miniaturization trend of the lithium battery system.

3. Fire extinguishing assembly 3

The fire extinguishing assembly 3 is a component in a lithium battery system for spraying fire extinguishing medium when preset conditions are met.

The fire extinguishing medium is a flame retardant gas, which may be carbon dioxide gas, or may be inert gas such as helium, neon, argon, krypton, xenon, radon, etc., and the type of the fire extinguishing medium is not limited in this embodiment.

As shown in fig. 1, the fire extinguishing assembly 3 is located within the cavity 1a and is connected to the inner wall of the housing 1.

The fire suppression assembly 3 includes a first receiving member 31.

As shown in fig. 3, the plurality of battery cells 2 includes a first battery cell 21 and a second battery cell 22, and the first battery cell 21 and the second battery cell 22 are the two battery cells farthest apart from each other among the plurality of battery cells 2.

The first accommodating member 31 is located inside the cavity 1a, on one side of the first battery cell 21 away from the second battery cell 22, and connected to the inner wall of the housing 1.

The first receiving part 31 is for receiving the fire extinguishing medium, and sprays the fire extinguishing medium into only the chamber 1a when the temperature inside the chamber 1a is greater than a preset reference temperature.

In this way, the arrangement of the plurality of battery cells 2 can be made compact, which is advantageous in that the lithium battery system tends to be miniaturized.

Optionally, the fire suppression assembly 3 may further comprise a second receiving member 32. The second receiving part 32 is for receiving the fire extinguishing medium, and sprays the fire extinguishing medium into only the chamber 1a when the temperature in the chamber 1a is greater than a preset reference temperature.

As shown in fig. 4, the second accommodating member 32 is located inside the cavity 1a and on a side of the second battery cell 22 away from the first battery cell 21, and is connected to the inner wall of the housing 1.

Referring to fig. 4, the second receiving container 32 is opposite to the opening of the first receiving container 31.

Fig. 4 is a plan view of the lithium battery system, the opening of the first receiving part 31 faces in the L direction, the opening of the second receiving part 32 faces in the M direction, and the M direction is the reverse direction of the L direction.

In practice, the first receiving container 31 and the second receiving container 32 may spray the extinguishing medium at the same time when the temperature in the chamber 1a is greater than a preset reference temperature. Referring to fig. 4, since the second receiving container 32 and the first receiving container 31 are opened in opposite directions, the fire extinguishing medium sprayed from the second receiving container 32 and the fire extinguishing medium sprayed from the first receiving container 31 may form a vortex inside the cavity 1a under the action of air pressure, thereby rapidly filling the entire cavity 1a with the fire extinguishing medium, flame retarding the battery cells where the combustion occurs, and preventing the remaining battery cells from being combusted.

In this way, the efficiency of the lithium battery system to solve thermal runaway can be improved.

The structure of the first receiving member 31 will be described.

In one example, the first receiving member 31 includes a first can 311 and a thermo valve 312.

As shown in fig. 5, the outer wall of the first tank 311 is connected to the outer wall of the first battery cell 21, the first tank 311 has a receiving chamber for receiving the high-pressure fire extinguishing medium, the first tank 311 has a first opening 311a, and the first opening 311a communicates with the receiving chamber and the chamber 1a. Both ends of the temperature control valve 312 are respectively connected to the first opening 311a and the cavity 1a, and the temperature control valve 312 is configured to be in an open state when the temperature in the cavity 1a is greater than a preset reference temperature.

The temperature in the cavity 1a may be the overall temperature of the cavity 1a, or may be the real-time temperature of a partial region in the cavity 1a, and the preset reference temperature may be set by a technician according to experimental data.

For example, the preset reference temperature is less than the actual combustion temperature of the battery cell 2, and the preset reference temperature may be set to 450 ℃.

Specifically, the battery cell 2 may be a lithium iron phosphate battery.

In practice, when combustion occurs in a lithium iron phosphate battery, the combustion temperature is about 500 ℃. Setting the preset reference temperature to be less than the actual combustion temperature of the battery cell 2 enables the first container 31 to spray the high-pressure fire extinguishing medium into the cavity 1a at the initial stage of combustion, thereby rapidly solving thermal runaway at the initial stage of combustion.

In one example, the first receiving member comprises a canister 311 and an electrically controlled valve 313, and the fire suppression assembly 3 further comprises a temperature sensor 33 and a controller 34.

As shown in fig. 6, the outer wall of the first tank 311 is connected to the outer wall of the first battery cell 21, the first tank 311 has a receiving chamber for receiving the high-pressure fire extinguishing medium, the first tank 311 has a first opening 311a, and the first opening 311a communicates with the receiving chamber and the chamber 1a. Both ends of the electric control valve 313 are respectively communicated with the first opening 311a and the cavity 1a.

The temperature sensor 33 is located inside the cavity 1a and connected to the outer wall of the battery cell 2, and the temperature sensor 33 is used for detecting the temperature inside the cavity 1a. The controller 34 is electrically connected to the electric control valve 313. The controller 34 is located inside the cavity 1a and connected to the outer wall of the first tank 311, and the controller 34 is configured to control the electric control valve 313 to be in an open state when the temperature in the cavity 1a is greater than a preset reference temperature.

Alternatively, the number of the temperature sensors 33 may be plural.

In one example, the number of the temperature sensors 33 may be the same as the number of the battery cells 2, each temperature sensor 33 is correspondingly disposed at the upper surface position of one battery cell 2, the plurality of temperature sensors 33 are electrically connected to the controller 34, and the controller 34 is configured to control the electric control valve 313 to be in an open state when the temperature detected by any one of the temperature sensors 33 is greater than a preset reference temperature.

In practice, when the battery cell 2 burns, the heated gas in the cavity 1a floats upwards, the temperature in the upper area of the cavity 1a rises faster, and the temperature sensor 33 is arranged on the upper surface of the battery cell 2, so that the controller can quickly control the electric control valve 313 to open when the battery cell 2 burns, and the high-pressure fire extinguishing medium is sprayed into the cavity 1a. When the single battery cell 2 burns, the temperature of the local area in the cavity 1a rises, and a temperature sensor 33 is correspondingly arranged on the upper surface of each battery cell 2, so that the controller 34 can rapidly control the electric control valve 313 to be opened when the single battery cell 2 burns, and the high-pressure fire extinguishing medium is sprayed into the cavity 1a.

In one example, the number of temperature sensors 33 may be less than the number of battery cells 2. The temperature sensor 33 may be located in a gap between two adjacent battery cells 2 and connected to the battery cell 2 adjacent to the first receiving member 31.

In this way, the number of temperature sensors 33 required for the fire suppression assembly 3 can be reduced, saving costs.

The structure of the second receiving member 33 will be described below.

In one example, the second receiving member 32 includes a second canister and a thermo valve.

The outer wall of the second tank body is connected with the outer wall of the second battery cell, the second tank body is provided with a containing cavity, the containing cavity is used for containing high-pressure fire extinguishing medium, the second tank body is provided with a fourth opening, and the fourth opening is communicated with the containing cavity and the cavity 1a. The two ends of the temperature control valve are respectively communicated with the fourth opening and the cavity 1a, and the temperature control valve is in an opening state when the temperature in the cavity 1a is greater than a preset reference temperature.

For example, the preset reference temperature is less than the actual combustion temperature of the battery cell, and the preset reference temperature may be set to 450 ℃.

Specifically, the battery cell may be a lithium iron phosphate battery.

In practice, when combustion occurs in a lithium iron phosphate battery, the combustion temperature is about 500 ℃. Setting the preset reference temperature to be less than the actual combustion temperature of the battery cell enables the second container to spray the high-pressure fire extinguishing medium into the cavity 1a at the initial stage of combustion, thereby rapidly solving thermal runaway at the initial stage of combustion.

In one example, the second housing assembly includes a tank and an electrically controlled valve, and the fire suppression assembly further includes a temperature sensor and a controller.

The outer wall of the second tank body is connected with the outer wall of the second battery cell, the second tank body is provided with a containing cavity, the containing cavity is used for containing high-pressure fire extinguishing medium, the second tank body is provided with a fourth opening, and the fourth opening is communicated with the containing cavity and the cavity 1a. The two ends of the electric control valve are respectively communicated with the fourth opening and the cavity 1a.

The temperature sensor is located inside the cavity 1a and connected with the outer wall of the battery cell, and the temperature sensor is used for detecting the temperature in the cavity 1a. The controller is electrically connected with the electric control valve. The controller is located inside the cavity 1a and connected with the outer wall of the second tank body, and the controller is used for controlling the electric control valve to be in an open state when the temperature in the cavity 1a is greater than a preset reference temperature.

Alternatively, the number of temperature sensors may be plural.

In an example, the number of the temperature sensors may be the same as the number of the battery cells, each temperature sensor is correspondingly disposed at the upper surface of one battery cell, the plurality of temperature sensors are electrically connected to the controller, and the controller is configured to control the electric control valve to be in an open state when the temperature detected by any one of the temperature sensors is greater than a preset reference temperature.

In implementation, when the battery monomer burns, heated gas in the cavity 1a floats upwards, the temperature of the upper area of the cavity 1a rises faster, and the temperature sensor is arranged on the upper surface of the battery monomer, so that the controller can quickly control the opening of the electric control valve when the battery monomer burns, and the high-pressure fire extinguishing medium is sprayed into the cavity 1a. When single battery monomer takes place to burn, the regional temperature in the cavity 1a rises, all corresponds at each single battery monomer's upper surface and is provided with a temperature sensor, can take place when burning at single battery monomer, and the automatically controlled valve of controller rapid control opens to make high-pressure extinguishing medium spray to the cavity 1a inside.

In one example, the number of temperature sensors may be less than the number of battery cells. The temperature sensor may be located in a gap between two adjacent battery cells and connected to the battery cell adjacent to the first receiving member.

In this way, the number of temperature sensors required for the fire suppression assembly can be reduced, saving costs.

In one example, the first accommodating element 31 includes a first tank 311 and a temperature control valve 312, the second accommodating element 32 includes a second tank and an electrically controlled valve, and the fire extinguishing assembly 3 further includes a temperature sensor 33 and a controller 34, and the controller 34 is electrically connected to the electrically controlled valve.

The opening temperature corresponding to the temperature control valve 312 may be a first preset reference temperature, and the temperature of the electric control valve of the second accommodating element 32 controlled by the controller 34 in the opening state may be a second preset reference temperature, where the second preset reference temperature is smaller than the first preset reference temperature.

Illustratively, the first preset reference temperature may be 480 ℃ and the second preset reference temperature may be 450 ℃.

In practice, as the temperature increases, the controller 34 may be damaged in a high-temperature environment, resulting in the second container 32 not being able to spray the high-pressure extinguishing medium into the chamber 1a when the combustion of the battery cell 2 occurs. The first tank body and the second tank body are respectively opened by the first temperature control valve and the electric control valve, so that when the controller fails, the first tank body can spray high-pressure fire extinguishing medium to the cavity to control the thermal runaway of the lithium battery system.

Some optional structural features of the lithium battery system are described below:

the lithium battery system comprises a plurality of pipelines.

As shown in fig. 7, the lithium battery system further includes a first pipe 4 and a second pipe 5.

The first pipe 4 is located in the cavity 1a, one end of the first pipe 4 is provided with a second opening 4a, the second opening 4a is communicated with the other end of the electric control valve 313, the first pipe 4 is provided with a plurality of first through holes 4b penetrating through the pipe wall, and each first through hole 4b is correspondingly communicated with one gap.

The second pipeline 5 is located in the cavity 1a and is located at one side, far away from the first pipeline 4, of the plurality of battery monomers 2, the outer wall of the second pipeline 5 is attached to the plurality of battery monomers 2, one end of the second pipeline 5 is provided with a third opening 5a, the third opening 5a is communicated with the exhaust hole 1b, the second pipeline 5 is provided with a plurality of second through holes 5b penetrating through the pipeline wall, and each second through hole 5a is correspondingly communicated with one gap.

In this way, under the diversion effect of the first pipe 4 and the second pipe 5, the fire extinguishing medium ejected from the first tank 311 can rapidly enter the gaps between the plurality of battery cells 2, so as to solve the thermal runaway of the lithium battery system.

Alternatively, the inner wall of the exhaust hole 1b may be provided with a check valve for being in an opened state when the air pressure in the cavity 1a is greater than a preset reference pressure.

In practice, as the high-pressure extinguishing medium is sprayed from the arc extinguishing assembly 3 into the cavity 1a, the air pressure in the cavity 1a is gradually increased, and the one-way valve is arranged on the inner wall of the air outlet hole 1b, so that the shell 1 can be prevented from being broken due to the excessively high air pressure in the cavity 1a. In addition, external air can be prevented from entering the cavity 1a through the exhaust hole 1b to assist combustion, and thus a flame retardant effect can be achieved.

The lithium battery system also comprises an exhaust fan 6.

As shown in fig. 7, the exhaust fan 6 is located in the exhaust hole 1b and is connected to the inner wall of the exhaust hole 1 b.

Alternatively, the exhaust fan 6 may be located in the inner wall of the exhaust hole 1b, on the side of the check valve away from the cavity 1a, and connected to the inner wall of the exhaust hole 1 b.

The third structural feature, the lithium battery system may further comprise a connection plate 7.

As shown in fig. 7, the connection plate 7 is located in the gap between the adjacent two battery cells 2 and is connected to the adjacent two battery cells 2.

Alternatively, the connection plate 7 may be parallel to the lower wall surface of the cavity 1a. The connection plate 7 has a plurality of connection through holes 7a in the vertical direction.

The above optional structural features may be used alone or in combination.

The embodiment of the application provides an electric automobile, which comprises the lithium battery system.

The electric automobile can be a pure electric automobile or a hybrid electric automobile, the embodiment of the application does not limit the type of the electric automobile,

the foregoing description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, since it is intended that all modifications, equivalents, improvements, etc. that fall within the spirit and scope of the invention.

Claims

1. A lithium battery system, characterized in that the lithium battery system is applied to an electric automobile, and comprises a shell (1), a plurality of battery cells (2) and a fire extinguishing assembly (3);

a cavity (1 a) is formed in the shell (1);

the battery cells (2) are positioned in the cavity (1 a) and are connected with the inner wall of the shell (1), wherein gaps are reserved between two adjacent battery cells (2);

the fire extinguishing assembly (3) is located in the cavity (1 a) and is connected with the inner wall of the shell (1), and the fire extinguishing assembly (3) is used for:

containing a fire extinguishing medium;

when the temperature in the cavity (1 a) is greater than a preset reference temperature, the extinguishing medium is sprayed into the cavity (1 a).

2. The lithium battery system according to claim 1, characterized in that the plurality of battery cells (2) are distributed in a matrix.

3. The lithium battery system according to claim 1 or 2, wherein the plurality of battery cells (2) comprises a first battery cell (21) and a second battery cell (22), wherein the first battery cell (21) and the second battery cell (22) are the two battery cells of the plurality of battery cells (2) that are furthest apart;

the fire extinguishing assembly (3) comprises a first accommodating component (31), wherein the first accommodating component (31) is positioned in the cavity (1 a), is positioned on one side, away from the second battery unit (22), of the first battery unit (21), and is connected with the inner wall of the shell (1).

4. A lithium battery system according to claim 3, characterized in that the fire extinguishing assembly (3) further comprises a second containing member (32), the second containing member (32) being located in the cavity (1 a) on the side of the second battery cell (22) remote from the first battery cell (21) and connected to the inner wall of the housing (1), the opening of the second containing member (32) being oriented opposite to the opening of the first containing member (31), the first containing member (31) and the second containing member (32) being both adapted to:

containing a fire extinguishing medium;

5. A lithium battery system according to claim 3, characterized in that the first receiving member (31) comprises a first tank (311) and a temperature control valve (312), the first tank (311) is used for receiving high-pressure fire extinguishing medium, the first tank (311) has a first opening (311 a), one end of the temperature control valve (312) is communicated with the first opening (311 a), the other end is communicated with the cavity (1 a), and the temperature control valve (312) is used for being in an opened state when the temperature in the cavity (1 a) is greater than a preset reference temperature.

6. A lithium battery system according to claim 3, characterized in that the fire extinguishing assembly (3) further comprises a temperature sensor (33) and a controller (34), the first housing closure (31) comprising a first tank (311) and an electrically controlled valve (313);

the first tank body (311) is used for containing high-pressure fire extinguishing medium, the first tank body (311) is provided with a first opening (311 a), one end of the electric control valve (313) is communicated with the first opening (311 a), and the other end of the electric control valve is communicated with the cavity (1 a);

the temperature sensor (33) is used for detecting the temperature in the cavity (1 a);

the controller (34) is used for controlling the electric control valve (313) to be in an opening state when the temperature in the cavity (1 a) is greater than the preset reference temperature.

7. The lithium battery system according to claim 6, characterized in that the housing (1) has a vent hole (1 b);

the lithium battery system further comprises a first pipeline (4) and a second pipeline (5);

the first pipeline (4) is positioned in the cavity (1 a), the outer wall of the first pipeline (4) is attached to the plurality of battery cells (2), one end of the first pipeline (4) is provided with a second opening (4 a), the second opening (4 a) is communicated with the other end of the electric control valve (313), the first pipeline (4) is provided with a plurality of first through holes (4 b) penetrating through the pipeline wall, and each first through hole (4 b) is correspondingly communicated with one gap;

the second pipeline (5) is located in the cavity (1 a), is located one side of the plurality of battery monomers (2) away from the first pipeline (4), the outer wall of the second pipeline (5) is attached to the plurality of battery monomers (2), one end of the second pipeline (5) is provided with a third opening (5 a), the third opening (5 a) is communicated with the exhaust hole (1 b), the second pipeline (5) is provided with a plurality of second through holes (5 b) penetrating through the pipeline wall, and each second through hole (5 a) is correspondingly communicated with one gap.

8. The lithium battery system according to claim 7, further comprising a vent fan (6), wherein the vent fan (6) is located in the vent hole (1 b) and is connected to an inner wall of the vent hole (1 b).

9. The lithium battery system according to any one of claims 1 to 8, wherein the fire extinguishing medium is carbon dioxide gas.

10. An electric vehicle, characterized in that it comprises the lithium battery system according to claim 9.