Device and method for automatically collecting and monitoring gas in lithium ion battery pack

Abstract

According to the automatic collecting and monitoring device and method for the gas in the lithium ion battery pack, in the device, a gas extracting pump is communicated with a second end through a second gas collecting pipe, and a gas storage tank is connected with the gas extracting pump through a third gas collecting pipe; the electronic timer is connected with the electromagnetic valve through an electromagnetic valve positive wire and an electromagnetic valve negative wire, the gas collection time is set through the electronic timer, so that the electromagnetic valve is opened at regular time, and the gas collector is connected with the electromagnetic valve through a gas collector interface via a fifth gas collection pipe so as to collect gas from the third end and obtain a gas concentration value. The upper computer is connected with the gas collector through a gas collector data line and connected with the sucking pump through a sucking pump control signal line, the upper computer compares the gas concentration value with a preset gas concentration threshold value, and when the gas concentration value exceeds the preset gas concentration threshold value, the sucking pump is opened through the sucking pump control signal line to suck gas and store the gas. The device improves the reliability and efficiency of collection, and can perform early warning and automatically extract gas.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion battery pack gas monitoring, and in particular to a device and method for automatically collecting and monitoring gas in a lithium-ion battery pack. Background Art

[0002] With the rapid development of power electronics technology and power battery technology, the continuous improvement of the research and development technology of new energy components represented by power batteries has laid a foundation for their wide application in vehicles. Among them, the fastest-growing and most core component is the vehicle-mounted power battery system (or power battery pack). In order to ensure the stability and reliability of all aspects of the power battery system before actual application, it is necessary to simulate the complex working conditions of the power battery system in actual application in advance in the laboratory environment, such as acceleration (battery discharge), deceleration (brake energy recovery, battery charging), etc. The test equipment used includes battery system charge and discharge tester, walk-in high and low temperature environment box, etc. According to the provided road condition data (power curve or current curve), the complex charge and discharge performance simulation test of the power battery system is carried out.

[0003] Lithium-ion battery cells that make up the vehicle power battery system / battery pack have the advantages of high energy density, long life and low self-discharge rate, and are widely used in electric vehicles, electronic equipment and other fields. During the charging and discharging process of lithium batteries, the negative electrode material and the electrolyte will react chemically to produce gas. The main gas component is carbon dioxide (CO 2 ) and oxygen (O 2 At the same time, some new lithium batteries may also release hydrogen (H 2 ) and methane (CH 4 ) and other gases. The amount of these gases released is affected by multiple factors such as the working state of the battery, the charging and discharging speed, temperature and internal pressure. The on-board power battery pack for new energy vehicles is composed of hundreds of battery cells (battery cells) combined in different series and parallel ways. During the charge and discharge test in the laboratory environment, hundreds of battery cells will produce different amounts of gas. If the battery leaks due to unqualified battery manufacturing process, and then the gas will leak into the battery pack box, when the gas accumulation of each component reaches a certain concentration, the battery pack will have certain safety risks.

[0004] In the prior art, the research objects of battery gas collection are mainly concentrated at the battery cell (battery cell) level, while there are almost no research objects on battery modules and battery packs. However, battery packs are used in actual vehicles, so it is more practical to study the gas collection and collection of battery packs as research objects. In the prior art, the collection of battery gas is done manually. The battery cells (cylindrical, soft pack or square shell) and other types of batteries are placed in a fixture or closed container. After the position is fixed, a steel needle or other tool is used to pierce a certain part of the battery. After the gas is released from the battery, the gas is collected with a specially designed gas collection device. This series of operations requires manual operation, which is time-consuming and laborious. If the combustible gas accumulates to a certain concentration, a safety hazard will occur.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a device and method for automatically collecting and monitoring gas in a lithium-ion battery pack, taking the battery pack as a research object to study its gas collection and collection, automatically collecting, collecting and warning according to the set time, improving the reliability and efficiency of the collection, ensuring that when the gas concentration in the battery pack box reaches the critical value, a real-time warning or alarm is issued, and the operator is notified in time to handle it safely. When the gas concentration in the box increases, the exhaust system can be turned on to extract and store the high-concentration gas, reduce the gas concentration in the battery pack box, and improve the safety of the battery pack during charge and discharge testing.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a device for automatically collecting and monitoring gas in a lithium-ion battery pack, comprising:

[0009] A battery pack comprising:

[0010] Box,

[0011] At least one battery module, which is assembled in series and parallel with a plurality of battery cells and integrated in the box,

[0012] A battery pack gas collection hole, which is provided on the box body to collect gas in the battery pack;

[0013] A three-way pipe includes a first end, a second end and a third end, wherein the first end is connected to the battery pack gas collection hole via a first gas collection pipe,

[0014] An air extraction system comprising:

[0015] a vacuum pump connected to the second end via a second gas collection pipe,

[0016] A gas storage tank connected to the gas pump via a third gas collection pipe;

[0017] a solenoid valve connected to the third end via a fourth gas collection pipe,

[0018] An electronic timer is connected to the solenoid valve via the positive line of the solenoid valve and the negative line of the solenoid valve. The gas collection time is set by the electronic timer so that the solenoid valve opens at a fixed time.

[0019] A gas collector is provided with a gas collector interface, and the gas collector is connected to the solenoid valve via the gas collector interface via a fifth gas collection pipe to collect gas from the third end and obtain a gas concentration value.

[0020] The host computer is connected to the gas collector via a gas collector data line and to the vacuum pump via a vacuum pump control signal line. The host computer compares the gas concentration value with a predetermined gas concentration threshold value, and turns on the vacuum pump through the vacuum pump control signal line to extract and store gas when the predetermined gas concentration threshold value is exceeded.

[0021] In the automatic gas collection and monitoring device in a lithium-ion battery pack, the host computer also includes an alarm unit, and when the gas concentration value exceeds the warning gas concentration threshold, the alarm unit issues an alarm.

[0022] In the automatic gas collection and monitoring device in a lithium-ion battery pack, the warning gas concentration threshold is less than the predetermined gas concentration threshold, and the alarm unit includes a pop-up prompt, an LED light or a buzzer.

[0023] In the automatic gas collection and monitoring device in a lithium-ion battery pack, when the gas concentration value received by the host computer is less than the warning gas concentration threshold, the host computer turns off the vacuum pump through the vacuum pump control signal line to stop vacuuming.

[0024] In the automatic gas collection and monitoring device in a lithium-ion battery pack, when the gas concentration value received by the host computer is less than a predetermined gas concentration threshold, the host computer turns off the vacuum pump through the vacuum pump control signal line to stop vacuuming.

[0025] In the device for automatically collecting and monitoring gas in a lithium-ion battery pack, the battery management system is connected to the battery module via a low-voltage communication line.

[0026] In the automatic gas collection and monitoring device for a lithium-ion battery pack, the charging and discharging system is connected to the battery pack via the positive electrode channel cable and the negative electrode channel cable and charges and discharges the battery pack to generate gases of different components.

[0027] In the automatic gas collection and monitoring device for a lithium-ion battery pack, a gas extraction valve is arranged on the second gas collection pipe to open and close the second gas collection pipe.

[0028] In the automatic gas collection and monitoring device in a lithium-ion battery pack, the power supply is connected to the electronic timer via a power neutral line and a power live line.

[0029] A monitoring method using the automatic gas collection and monitoring device in a lithium-ion battery pack includes:

[0030] The electronic timer sets the gas collection time, so that the solenoid valve opens at a fixed time;

[0031] The gas collector is connected to the solenoid valve through the gas collector interface via the fifth gas collection pipe to collect gas from the third end and obtain a gas concentration value;

[0032] The host computer compares the gas concentration value with the warning gas concentration threshold and the preset gas concentration threshold. When the gas concentration value exceeds the warning gas concentration threshold, an alarm is issued, and when it exceeds the preset gas concentration threshold, the vacuum pump is turned on through the vacuum pump control signal line to extract gas and store it.

[0033] In the above technical scheme, the present invention provides an automatic gas collection and monitoring device and method in a lithium-ion battery pack, which has the following beneficial effects: the automatic gas collection and monitoring device in a lithium-ion battery pack is based on gas collection at the battery pack level, which is closer to the actual vehicle application situation, and can automatically collect gas according to the set time interval, reducing the operation intensity of personnel and improving work efficiency. In the present invention, the gas concentration value in the gas collector is transmitted to the host computer of the host computer, and the gas concentration value can be monitored in real time. When the concentration value approaches the safety threshold, the operator can be informed by early warning, reducing the risk; when the safety threshold is reached, the exhaust system can be turned on to reduce the gas concentration in the battery pack box, and improve the safety of the sample during the battery pack test (especially the cycle life test). The electronic timer and the host computer automatically collect the gas in the box, and can automatically collect and monitor for weeks or months without the need for a dedicated person to manually operate, which reduces the potential operating cost in terms of economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0035] Figure 1 A schematic diagram of the structure of a device for automatically collecting and monitoring gas in a lithium-ion battery pack provided by an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] Among them, 1-charging and discharging system, 2-power supply, 3-host computer, 4-gas storage tank, 5-air pump, 6-battery pack, 7-low-voltage communication line, 8-battery management system, 9-positive channel cable, 10-negative channel cable, 11-battery module, 12-power neutral line, 13-power live line, 14-electronic timer, 15-solenoid valve positive line, 16-solenoid valve negative line, 17-solenoid valve, 18-fourth gas collection tube, 19-battery pack gas collection hole, 20-first gas collection tube, 21-three-way tube, 22-second gas collection tube, 23-air pump valve, 24-fifth gas collection tube, 25-gas collection instrument interface, 26-gas collection instrument, 27-gas collection instrument data line, 28-air pump control signal line, 29-third gas collection tube. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] See also Figure 1 As shown, in one embodiment, a device for automatically collecting and monitoring gas in a lithium-ion battery pack of the present invention comprises:

[0041] A battery pack 6, comprising:

[0042] Box,

[0043] At least one battery module 11, which is composed of a plurality of battery cells connected in series and parallel and integrated in the box,

[0044] A battery pack gas collection hole 19, which is provided in the box to collect gas in the battery pack 6;

[0045] A charging and discharging system 1, which is connected to a battery pack 6 and charges and discharges the battery pack 6 to generate gases of different components;

[0046] The three-way pipe 21 includes a first end, a second end and a third end. The first end is connected to the battery pack gas collection hole 19 via the first gas collection pipe 20.

[0047] An air extraction system comprising:

[0048] The air pump 5 is connected to the second end via the second gas collection pipe 22,

[0049] A gas storage tank 4 connected to the gas pump 5 via a third gas collection pipe 29;

[0050] The electromagnetic valve 17 is connected to the third end via the fourth gas collection pipe 18,

[0051] The electronic timer 14 is connected to the solenoid valve 17 via the positive line 15 and the negative line 16 of the solenoid valve. The gas collection time is set by the electronic timer 14 so that the solenoid valve 17 is opened at a fixed time.

[0052] The gas collector 26 is provided with a gas collector interface 25. The gas collector 26 is connected to the solenoid valve 17 via the gas collector interface 25 and the fifth gas collection pipe 24 to collect gas from the third end and obtain a gas concentration value.

[0053] The host computer 3 is connected to the gas collector 26 via the gas collector data line 27 and to the vacuum pump 5 via the vacuum pump control signal line 28. The host computer 3 compares the gas concentration value with a predetermined gas concentration threshold value, and opens the vacuum pump 5 through the vacuum pump control signal line 28 to extract and store gas when the predetermined gas concentration threshold value is exceeded.

[0054] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, the host computer 3 further includes an alarm unit, and when the gas concentration value exceeds the warning gas concentration threshold, the alarm unit issues an alarm.

[0055] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, the warning gas concentration threshold is less than the predetermined gas concentration threshold, and the alarm unit includes a pop-up prompt, an LED light or a buzzer.

[0056] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, when the gas concentration value received by the host computer 3 is less than the warning gas concentration threshold, the host computer 3 turns off the vacuum pump 5 through the vacuum pump control signal line 28 to stop vacuuming.

[0057] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, when the gas concentration value received by the host computer 3 is less than a predetermined gas concentration threshold, the host computer 3 turns off the vacuum pump 5 through the vacuum pump control signal line 28 to stop vacuuming.

[0058] In a preferred embodiment of the device for automatically collecting and monitoring gas in a lithium-ion battery pack, the battery management system 8 is connected to the battery module 11 via a low-voltage communication line 7 .

[0059] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, the charging and discharging system 1 is connected to the battery pack 6 via the positive channel cable 9 and the negative channel cable 10 and charges and discharges the battery pack 6 to generate gases of different components.

[0060] In a preferred embodiment of the automatic gas collection and monitoring device in a lithium-ion battery pack, a gas extraction valve 23 is provided on the second gas collection pipe 22 to open and close the second gas collection pipe 22 .

[0061] In a preferred embodiment of the device for automatically collecting and monitoring gas in a lithium-ion battery pack, the power supply 2 is connected to the electronic timer 14 via a neutral power line 12 and a live power line 13 .

[0062] In one embodiment, a device for automatically collecting and monitoring gas in a lithium-ion battery pack includes:

[0063] A battery pack 6, comprising:

[0064] Box,

[0065] At least one battery module 11, which is composed of a plurality of battery cells connected in series and parallel and integrated in the box,

[0066] The battery management system 8 is connected to the battery module 11 via a low voltage communication line 7.

[0067] A battery pack gas collection hole 19, which is provided in the box to collect gas in the battery pack 6;

[0068] A charging and discharging system 1, which is connected to a battery pack 6 via a positive channel cable 9 and a negative channel cable 10 and charges and discharges the battery pack 6 to generate gases of different components;

[0069] The three-way pipe includes a first end, a second end and a third end. The first end is connected to the battery pack gas collection hole 19 via the first gas collection pipe 20.

[0070] An air extraction system comprising:

[0071] The air pump 5 is connected to the second end via the second gas collection pipe 22,

[0072] The gas extraction valve 23 is provided on the second gas collection pipe 22 to open and close the second gas collection pipe 22.

[0073] A gas storage tank 4 connected to the gas pump 5 via a third gas collection pipe 29;

[0074] The electromagnetic valve 17 is connected to the third end via the fourth gas collection pipe 18,

[0075] The electronic timer 14 is connected to the solenoid valve 17 via the solenoid valve positive line 15 and the solenoid valve negative line 16.

[0076] A power source 2 is connected to the electronic timer 14 via a power neutral line 12 and a power live line 13,

[0077] The gas collector 26 is provided with a gas collector interface 25. The gas collector 26 is connected to the solenoid valve 17 via the gas collector interface 25 and the fifth gas collection pipe 24 to collect gas from the third end and obtain a gas concentration value.

[0078] The host computer 3 is connected to the gas collector 26 via the gas collector data line 27 and to the vacuum pump 5 via the vacuum pump control signal line 28. The host computer 3 compares the gas concentration value with a predetermined gas concentration threshold value, and opens the vacuum pump 5 through the vacuum pump control signal line 28 to extract and store gas when the predetermined gas concentration threshold value is exceeded.

[0079] A monitoring method using an automatic gas collection and monitoring device in a lithium-ion battery pack includes:

[0080] The charging and discharging system 1 is connected to the battery pack 6 and charges and discharges the battery pack 6 to generate gases of different components;

[0081] The electronic timer 14 sets the gas collection time so that the solenoid valve 17 opens at a fixed time, and the gas collector 26 is connected to the solenoid valve 17 via the gas collector interface 25 and the fifth gas collection pipe 24 to collect gas from the third end and obtain the gas concentration value;

[0082] The upper computer 3 compares the gas concentration value with the warning gas concentration threshold and the predetermined gas concentration threshold. When the gas concentration value exceeds the warning gas concentration threshold, an alarm is issued, and when it exceeds the predetermined gas concentration threshold, the vacuum pump 5 is turned on through the vacuum pump control signal line 28 to extract gas and store it.

[0083] In one embodiment, gas is generated based on charging and discharging the power lithium-ion battery pack 6, especially during hundreds or even thousands of cycles. As the battery pack 6 is continuously charged and discharged, the internal cells of the lithium-ion battery pack 6 continuously undergo chemical oxidation and reduction reactions, which will cause the electrolyte of the internal battery cells to decompose, thereby generating a large amount of gas. The composition of the generated gas and the alarm limit are specifically shown in Table 1.

[0084] Table 1 Gas and alarm limits in battery pack 6

[0085]

[0086] During the performance test of the power battery pack 6, the battery pack 6 needs to be continuously charged and discharged, and gas may be continuously generated, which may cause the battery monomer to swell. If some monomers are not rolled tightly due to manufacturing process technology problems, the gas generated in the battery monomer may leak into the battery pack 6 box. If the concentration of the combustible gas therein continues to increase to a certain combustible concentration, if at this time there is a spark generated by a short circuit inside the battery pack 6 due to abnormal reasons, the combustible gas in the battery pack 6 box will be ignited, which will inevitably ignite the battery monomers and modules in the battery pack 6, causing thermal runaway, causing the lithium battery to smoke, catch fire or even explode. Based on the above safety hazards, the present invention uses an automatic collection and monitoring device to regularly collect and identify the gas in the power battery pack 6 box that is undergoing a cycle life test, and monitors it in real time through the host computer 3. The data of all gases in the box are stored in the host computer 3, and are compared and analyzed in real time with the safety threshold preset in the host computer 3. Once the concentration of a certain component gas approaches the set threshold, the fault level is Level A - Warning (Warning), and a pop-up window will appear on the interface of the host computer 3, and a text message will be sent to the operator to remind the operator to take timely action. If the operator does not find the fault warning in time, then wait for the concentration to increase to Level B (Alarm) - Alarm level, then the host computer 3 will automatically open the valve of the exhaust pipeline through the control signal line of the exhaust pump 5, and the exhaust pump 5 will start to run, pumping high-concentration combustible gas into the gas storage tank 4, reducing the concentration of combustible gas in the battery pack 6 box, so as to ensure that the concentration of each component gas in the box is within a reasonable and safe threshold range, ensuring the safety of personnel and battery pack 6 samples.

[0087] In one embodiment, the minimum collection interval may be set to 0.1 s.

[0088] In one embodiment, the battery charging and discharging system 1 is used to charge and discharge the battery pack 6. The specific charging or discharging action is controlled by the instructions in the industrial computer. The charging and discharging equipment and the industrial computer are connected by CAN communication. The battery pack 6 is a sample to be tested, which needs to be connected to the charging and discharging equipment through positive and negative channel cables, and connected to the industrial computer through a CAN communication line. The battery pack 6 has a battery management system 8 (BMS) and several battery modules 11 composed of countless battery cells in different series and parallel modes. The battery pack 6 can be charged and discharged with different currents through the charging and discharging equipment. A gas collection hole is provided on the battery pack 6 for installing a gas collection tube. The collection hole is an outward convex structure, which is convenient for installing a gas collection tube. The gas collector 26 is mainly used to collect the gas components in the battery pack 6 box through the gas collection hole and the collection pipeline during the charging and discharging process of the battery pack 6, and transmit the gas concentration value to the host computer 3 through the data line. The host computer 3 is mainly used to collect the gas concentration data values ​​transmitted back by the gas collector 26, and compare them with the gas concentration threshold value pre-set in the host computer 3, and open the vacuum pump 5 through the control line to extract and store gas when the concentration is high. The electronic timer 14 is mainly used to set different time intervals so that the solenoid valve 17 can be opened at a timed interval, so that the gas collector 26 can collect the gas in the battery pack 6 box. The time interval of the timer can be set at will, and the minimum collection interval can be set to 0.1s. The exhaust system and the gas storage tank 4 are mainly used to pump the hot gas from the battery pack 6 box into the gas storage tank 4 by opening the vacuum pump 5 when the combustible gas concentration in the battery pack 6 box reaches a certain peak value, so as to ensure that the concentration of the combustible gas in the battery pack 6 box is within the safety limit. The charging and discharging system 1 charges and discharges the battery pack 6 through the positive and negative channel cables 10 connected to the battery pack 6. During the charging and discharging process, combustible gases of different components will be generated in the battery pack 6 box.

[0089] In one embodiment, the electronic timer 14 is powered by a 220V power supply 2 and is connected to the solenoid valve 17 to control the opening and closing of the solenoid valve 17 according to a set time interval. The gas collector 26 is used to collect the gas in the battery pack 6 box and transmit the gas concentration value to the upper computer 3 of the upper computer 3. The upper computer 3 is mainly used to store the concentration value of the collected gas, and when the gas concentration reaches a threshold, control the vacuum pump 5 and the vacuum valve to open to reduce the concentration of the gas in the box. The vacuum pump 5 is mainly used to extract high-concentration combustible gas from the battery pack 6 box and send it to the gas storage tank 4. The gas storage tank 4 is mainly used to temporarily store high-concentration combustible gas extracted from the battery pack 6 box.

[0090] The working process or action process of the present invention is as follows:

[0091] exist Figure 1In the embodiment, the battery pack 6 includes a battery management system (BMS) 8 and several battery modules 11 composed of hundreds of battery cells connected in series and parallel in different ways. The battery management system 8 is connected to the battery module 11 through a low-voltage communication line 7 to communicate information (such as voltage, current, temperature, etc.). There is a gas collection hole 19 on the battery pack box 6. The battery charging and discharging device 1 is connected to the positive and negative interfaces of the high-voltage line on the battery pack 6 through the positive channel cable 9 and the negative channel cable 10, and can perform charging and discharging operations on the battery pack 6 with different currents.

[0092] The electronic timer 14 is connected to a 220V power supply 12 via a live power line 13 and a neutral power line 12 , and is connected to a solenoid valve 17 via a positive solenoid valve line 15 and a negative solenoid valve line 16 .

[0093] The gas collector 26 is connected to the host computer 3 via the gas collector data line 27. The solenoid valve 17 opens on time according to the time interval set by the electronic timer 14. The gas in the battery pack 6 will flow along the first gas collection tube 20, the three-way tube 21, the fourth gas collection tube 18, the solenoid valve 17, the fifth gas collection tube 24, and the gas collector interface 25 to reach the gas collector 26. Then the gas collector 26 transmits the measured gas concentration value in the battery pack box to the host computer 3 via the gas collector data line 27.

[0094] If the gas concentration is within the safety threshold range, the host computer does not perform any action, but only records the gas concentration value at the set time interval. However, when the gas concentration reaches Level A, a warning pop-up window will appear on the host computer 3, and a text message will be sent to the operator's mobile phone to remind the operator to take safety measures in time. If the operator does not find the pop-up window and text message in time, the gas concentration in the battery pack will continue to increase. When the concentration reaches Level B, the host computer will control the air pump valve 23 and the air pump 5 to open and operate through the air pump control signal line 28, and the gas in the battery pack box 6 will pass through the gas collection hole 19, the first gas collection tube 20, the three-way pipe 21, the second gas collection tube 22, the air pump valve 23, the air pump 5, and the third gas collection tube 29 to the gas storage tank 4, thereby reducing the concentration of the gas in the battery pack box 6 and ensuring the safety of the battery pack sample. At this time, when the gas concentration in the battery pack 6 is reduced, the upper computer 3 controls the air extraction valve 23 and the air extraction pump to be closed through the control line, and the gas collector 26 can collect gas according to the time interval set by the electronic timer 14. The high-concentration combustible gas stored in the gas storage tank 4 will be regularly handed over to a company with gas treatment qualifications for safe treatment.

[0095] Finally, it should be noted that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present application.

[0096] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A device for automatically collecting and monitoring gas in a lithium-ion battery pack, characterized in that: These include, A battery pack comprising: Box, At least one battery module, which is assembled in series and parallel with a plurality of battery cells and integrated in the box, A battery pack gas collection hole, which is provided on the box body to collect gas in the battery pack; A three-way pipe includes a first end, a second end and a third end, wherein the first end is connected to the battery pack gas collection hole via a first gas collection pipe, An air extraction system comprising: a vacuum pump connected to the second end via a second gas collection pipe, A gas storage tank connected to the gas pump via a third gas collection pipe; a solenoid valve connected to the third end via a fourth gas collection pipe, An electronic timer is connected to the solenoid valve via the positive line of the solenoid valve and the negative line of the solenoid valve. The gas collection time is set by the electronic timer so that the solenoid valve opens at a fixed time. A gas collector is provided with a gas collector interface, and the gas collector is connected to the solenoid valve via the gas collector interface via a fifth gas collection pipe to collect gas from the third end and obtain a gas concentration value. The host computer is connected to the gas collector via a gas collector data line and to the vacuum pump via a vacuum pump control signal line. The host computer compares the gas concentration value with a predetermined gas concentration threshold value, and turns on the vacuum pump through the vacuum pump control signal line to extract and store gas when the predetermined gas concentration threshold value is exceeded.

2. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: The host computer further includes an alarm unit, which issues an alarm when the gas concentration value exceeds a warning gas concentration threshold.

3. The automatic gas collection and monitoring device for a lithium-ion battery pack according to claim 2, characterized in that: The warning gas concentration threshold is less than the predetermined gas concentration threshold, and the alarm unit includes a pop-up prompt, an LED light or a buzzer.

4. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 2, characterized in that: When the gas concentration value received by the host computer is less than the warning gas concentration threshold, the host computer turns off the vacuum pump through the vacuum pump control signal line to stop vacuuming.

5. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: When the gas concentration value received by the host computer is less than a predetermined gas concentration threshold, the host computer turns off the air pump through the air pump control signal line to stop pumping gas.

6. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: The battery management system is connected to the battery modules via a low voltage communication line.

7. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: The charge and discharge system connects the battery pack via the positive channel cable and the negative channel cable and charges and discharges the battery pack to generate gases of different compositions.

8. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: The gas extraction valve is arranged on the second gas collection pipe to open and close the second gas collection pipe.

9. The automatic gas collection and monitoring device in a lithium-ion battery pack according to claim 1, characterized in that: The power source is connected to the electronic timer via a power neutral line and a power live line.

10. A monitoring method using the automatic gas collection and monitoring device in a lithium-ion battery pack according to any one of claims 1 to 9, characterized in that: These include, The electronic timer sets the gas collection time, so that the solenoid valve opens at a fixed time; The gas collector is connected to the solenoid valve through the gas collector interface via the fifth gas collection pipe to collect gas from the third end and obtain a gas concentration value; The host computer compares the gas concentration value with the warning gas concentration threshold and the preset gas concentration threshold. When the gas concentration value exceeds the warning gas concentration threshold, an alarm is issued, and when it exceeds the preset gas concentration threshold, the vacuum pump is turned on through the vacuum pump control signal line to extract gas and store it.

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