Battery cell thermal runaway detection system of lithium battery module

Abstract

The invention discloses a battery cell thermal runaway detection system of a lithium battery module, and belongs to the field of power battery thermal runaway prediction.The system comprises battery cells distributed in the lithium battery module in rows and columns, light-operated circuits are arranged at ventilation channels between the adjacent battery cells, and a movable wind shield is arranged on each battery cell; the first U-shaped sliding rail and the second U-shaped sliding rail are adjacent and are vertically arranged, the first U-shaped sliding rail is arranged on one side of all the battery cells distributed in rows, the second U-shaped sliding rail is arranged on one side of all the battery cells distributed in columns, and a first sliding rod and a first lead screw nut transmission device are arranged at the two ends of the first U-shaped sliding rail; a second sliding rod and a second lead screw nut transmission device are arranged at the two ends of the second U-shaped sliding rail, a first movable fan with an LED lamp is arranged on the first U-shaped sliding rail, and a second movable fan with an LED lamp is arranged on the second U-shaped sliding rail. The device is used for rapidly detecting the thermal runaway of the battery and positioning the position of the thermal runaway battery cell.

Description

Technical Field

[0001] The present invention belongs to the field of thermal runaway prediction of power batteries, and in particular relates to a thermal runaway detection system for cells of a lithium battery module. Background Art

[0002] Thermal runaway of power batteries refers to the phenomenon of overheating, fire, and explosion caused by a chain reaction of heat release from single batteries, which causes a sharp change in the temperature rise rate of the battery. The causes of thermal runaway of power batteries include: thermal runaway triggered by overheating, thermal runaway triggered by overcharging, thermal runaway triggered by internal short circuit, thermal runaway triggered by mechanical collision, etc. Signs before thermal runaway of power batteries include: temperature rise, expansion, voltage fluctuation, gas emission, etc.

[0003] Common thermal runaway detection methods include terminal voltage detection and overtemperature detection. However, after these two methods detect thermal runaway anomalies, a thermal runaway chain reaction has often occurred, and it is too late to take measures. Therefore, it is urgent to design a more reasonable thermal runaway detection method to speed up thermal runaway detection and improve thermal runaway positioning accuracy. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a battery cell thermal runaway detection system for a lithium battery module. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] An embodiment of the present invention provides a battery cell thermal runaway detection system for a lithium battery module, the system comprising:

[0006] A lithium battery module, wherein a plurality of battery cells are arranged in rows and columns in the lithium battery module, and a light control circuit is arranged at the ventilation passage between adjacent battery cells, the light control circuit includes a gas sensor, and a movable wind shield is arranged on each battery cell; a first U-shaped slide rail and a second U-shaped slide rail, wherein the first U-shaped slide rail and the second U-shaped slide rail are adjacent and vertically arranged, the first U-shaped slide rail is arranged on one side of all battery cells arranged in rows, and the second U-shaped slide rail is arranged on one side of all battery cells arranged in columns, a first slide rod and a first lead screw nut transmission device are arranged at both ends of the first U-shaped slide rail, a second slide rod and a second lead screw nut transmission device are arranged at both ends of the second U-shaped slide rail, and a first movable fan carrying an LED lamp is arranged on the first U-shaped slide rail, and a second movable fan carrying an LED lamp is arranged on the second U-shaped slide rail; wherein the process of detecting thermal runaway of battery cells using the system includes:

[0007] During the movement of the first movable fan, when the first movable fan reaches a certain ventilation channel along the first U-shaped slide rail, the first movable fan stays at the ventilation channel, blows away the abnormal thermal runaway gas diffused from other places in the early stage, and dissipates the heat, then the light control circuit arranged at the ventilation channel is turned on, at this time the movable wind shield plate at the ventilation channel is parallel to the wind direction, if the gas sensor in the light control circuit arranged at the ventilation channel receives a thermal runaway gas signal, then there are battery cells on both sides of the ventilation channel in a thermal runaway state; the first movable fan continues to move to the next ventilation channel, at this time the light control circuit arranged at the previous ventilation channel is turned off, and the light control circuit arranged at the current ventilation channel is turned on, if the gas sensor arranged at the current ventilation channel still receives a thermal runaway gas signal, then the row where the battery cell in a thermal runaway state is located is located;

[0008] During the movement of the second movable fan, when the second movable fan reaches a certain ventilation channel along the second U-shaped slide rail, the second movable fan stays at the ventilation channel, blows away the abnormal thermal runaway gas diffused from other places in the early stage, and after the heat is dissipated, the light control circuit arranged at the ventilation channel is turned on. At this time, the movable wind shield plate at the ventilation channel is parallel to the wind direction. If the gas sensor in the light control circuit arranged at the ventilation channel receives a thermal runaway gas signal, then there are battery cells on both sides of the ventilation channel in a thermal runaway state; the second movable fan continues to move to the next ventilation channel, at this time the light control circuit arranged at the previous ventilation channel is turned off, and the light control circuit arranged at the current ventilation channel is turned on. If the gas sensor arranged at the current ventilation channel still receives a thermal runaway gas signal, then the column where the battery cells in a thermal runaway state are located is located;

[0009] The battery cell in the thermal runaway state is located according to the row and column where the battery cell in the thermal runaway state is located.

[0010] Beneficial effects of the present invention:

[0011] The battery cell thermal runaway detection system for a lithium battery module proposed in the present invention can be used to quickly detect battery thermal runaway and locate the position of the thermal runaway battery cell. Specifically: the first sliding rod and the first lead screw nut transmission device at both ends of the first U-shaped slide rail can control the first U-shaped slide rail to move up and down, thereby driving the first movable fan to move up and down. Similarly, the second sliding rod and the second lead screw nut transmission device at both ends of the second U-shaped slide rail can control the second U-shaped slide rail to move up and down, thereby driving the second movable fan to move up and down. The upper and lower positions of the first movable fan and the second movable fan can be changed, thereby achieving comprehensive heat dissipation of the thermal runaway gas of the lithium battery while uniformly dissipating the heat. Position detection; the first movable fan and the second movable fan move on the first U-shaped slide rail and the second U-shaped slide rail respectively. When the two movable fans move to each ventilation channel respectively, since both movable fans carry LED lights, the LED lights will trigger the light control circuit at the ventilation channel, and then the gas sensor in the light control circuit performs thermal runaway abnormality detection, locates the row and column where the thermal runaway battery cell is located, and quickly locates the position of the thermal runaway battery cell according to the row and column where the thermal runaway battery cell is located, and the movable wind shield closes the ventilation channel perpendicular to the wind direction, so that the thermal runaway gas is quickly transferred to the gas sensor, thereby accelerating the thermal runaway detection speed. In general, the present invention can achieve rapid detection and precise positioning of the position of the thermal runaway battery cell through the coordinated work of the light control circuit, the movable wind shield and the movable fan.

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a battery cell thermal runaway detection system for a lithium battery module provided by an embodiment of the present invention;

[0014] Figure 2 The embodiment of the present invention provides Figure 1 A partial enlarged view of the vertical intersection of two U-shaped rails;

[0015] Figure 3 The embodiment of the present invention provides Figure 1 A partial enlarged view from another angle at the vertical intersection of two U-shaped rails;

[0016] Figure 4 A schematic diagram of the circuit structure of a light control circuit provided in an embodiment of the present invention;

[0017] Figure 5 A schematic structural diagram of a screw and nut transmission device provided in an embodiment of the present invention;

[0018] Figure 6 A schematic diagram of the structure of a movable fan provided by an embodiment of the present invention;

[0019] Figure 7 A schematic diagram of the structure of a selection switch provided in an embodiment of the present invention;

[0020] Figure 8 A schematic diagram of the air outlet position and structure provided in an embodiment of the present invention;

[0021] Fig. 9 A schematic diagram of the structure of the movable windshield and the position of the temperature sensor provided in an embodiment of the present invention;

[0022] Fig.10 A schematic diagram of the structure of a movable windshield provided in an embodiment of the present invention;

[0023] Fig.11 A schematic diagram of the gas flow between row-distributed battery cells provided in an embodiment of the present invention;

[0024] Fig.12 A schematic diagram of the gas flow between row-distributed battery cells provided in an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1-first slide bar; 2-selection switch; 3-first U-shaped slide rail; 4-first movable fan; 5-first screw-nut transmission device; 6-second slide bar; 7-second U-shaped slide rail; 8-second movable fan; 9-second screw-nut transmission device; 10-movable wind shield; 11-air outlet; 12-battery cell; 13-nut; 14-screw; 15-first micro motor; 16-first micro reducer; 17-fan; 18-LED lamp; 19-second micro reducer; 20-pulley; 21-second micro motor; 22-gas sensor; 23-rotating part; 24-third micro reducer; 25-third micro motor; 26-base; 27-temperature sensor; 28-central axis; 29-wind shield B surface; 30-wind shield A surface. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0028] See also Figure 1 , Figure 2 and Figure 3 The embodiment of the present invention provides a battery cell thermal runaway detection system for a lithium battery module, the system comprising:

[0029] A lithium battery module, wherein a plurality of battery cells 12 are arranged in rows and columns in the lithium battery module, a light control circuit is arranged at the ventilation passage between adjacent battery cells 12, the light control circuit includes a gas sensor, and a movable wind shield 10 is arranged on each battery cell 12; a first U-shaped slide rail 3 and a second U-shaped slide rail 7, the first U-shaped slide rail 3 and the second U-shaped slide rail 7 are adjacent and vertically arranged, the first U-shaped slide rail 3 is arranged on one side of all battery cells 12 arranged in rows, the second U-shaped slide rail 7 is arranged on one side of all battery cells 12 arranged in columns, a first slide bar 1 and a first lead screw nut transmission device 5 are arranged at both ends of the first U-shaped slide rail 3, a second slide bar 6 and a second lead screw nut transmission device 9 are arranged at both ends of the second U-shaped slide rail 7, a first movable fan 4 carrying an LED lamp is arranged on the first U-shaped slide rail 3, and a second movable fan 8 carrying an LED lamp is arranged on the second U-shaped slide rail 7; wherein, the process of detecting thermal runaway of battery cells using the system includes:

[0030] During the movement of the first movable fan 4, when the first movable fan 4 reaches a certain ventilation channel along the first U-shaped slide rail 3, the first movable fan 4 stays at the ventilation channel. At this time, the light control circuit at the ventilation channel is not turned on, but the first movable fan 4 first blows away the abnormal thermal runaway gas diffused from other places in the early stage, and the heat is blown away, and then the light control circuit set at the ventilation channel is turned on, that is, the light control circuit is delayed. At this time, the movable wind shield 10 at the ventilation channel is parallel to the wind direction, closing the ventilation channel perpendicular to the wind direction. If the ventilation channel is set If the gas sensor in the light-controlled circuit can receive the thermal runaway gas signal, then there must be battery cells 12 on both sides of the ventilation channel in a thermal runaway state; the first movable fan 4 continues to move to the next ventilation channel, at which time the light-controlled circuit set at the previous ventilation channel is turned off, and the light-controlled circuit set at the current ventilation channel is turned on. If the gas sensor set at the current ventilation channel can still receive the thermal runaway gas signal, then the row where the battery cells 12 in a thermal runaway state are located is located, that is, the row where the battery cells between the current ventilation channel and the previous ventilation channel are located is located as the row where the battery cells 12 in a thermal runaway state are located;

[0031] During the movement of the second movable fan 8, when the second movable fan 8 reaches a certain ventilation channel along the second U-shaped slide rail 7, the second movable fan 8 stays at the ventilation channel. At this time, the light control circuit at the ventilation channel is not turned on, but the second movable fan 8 first blows away the abnormal thermal runaway gas diffused from other places in the early stage, and after the heat is blown away, the light control circuit set at the ventilation channel is turned on, that is, the light control circuit is turned on with delay. At this time, the movable wind shield 10 at the ventilation channel is parallel to the wind direction, closing the ventilation channel perpendicular to the wind direction. If the ventilation channel is set If the gas sensor in the light-controlled circuit can receive the thermal runaway gas signal, then there are battery cells 12 on both sides of the ventilation channel in a thermal runaway state; the second movable fan 8 continues to move to the next ventilation channel, at which time the light-controlled circuit set at the previous ventilation channel is turned off, and the light-controlled circuit set at the current ventilation channel is turned on. If the gas sensor set at the current ventilation channel can still receive the thermal runaway gas signal, then the column where the battery cells 12 in a thermal runaway state are located is located, that is, the column where the battery cells between the current ventilation channel and the previous ventilation channel are located is located as the column where the battery cells 12 in a thermal runaway state are located;

[0032] The battery cell 12 in the thermal runaway state is located according to the row and column where the battery cell 12 in the thermal runaway state is located.

[0033] The light control circuit of the embodiment of the present invention also includes multiple temperature sensors, denoted as temperature sensor W1 to temperature sensor Wn. The abnormality of temperature sensor W1 to temperature sensor Wn can locate the range of thermal runaway of the battery cell, and further use the gas sensor to locate the specific row or column of the battery cell where thermal runaway occurs.

[0034] The moving process of the embodiment of the present invention includes a first half cycle and a second half cycle; wherein,

[0035] In the first half cycle, the first movable fan 4 moves along the first U-shaped slide rail 3 from the vertical intersection to the first slide bar 1, and the second movable fan 8 moves along the second U-shaped slide rail 7 from the second lead screw nut transmission device 9 to the vertical intersection; wherein the vertical intersection is the intersection of the adjacent first U-shaped slide rail 3 and the second U-shaped slide rail 7; the first lead screw nut transmission device 5 and the second slide bar 6 are arranged at the vertical intersection;

[0036] In the second half cycle, the first screw nut transmission device 5 and the first slide bar 1, the second screw nut transmission device 9 and the second slide bar 6 respectively control the first U-shaped slide rail 3 and the second U-shaped slide rail 7, so that the first movable fan 4 and the second movable fan 8 can change the upper and lower positions. The first movable fan 4 moves along the first U-shaped slide rail 3 from the first slide bar 1 to the vertical intersection, and the second movable fan 8 moves along the second U-shaped slide rail 7 from the vertical intersection to the second screw nut transmission device 9, thereby avoiding the problem of mutual interference caused by the two movable fans being at the right-angle intersection at the same time.

[0037] For example, taking the vertical intersection as the initial position, the cells perpendicular to the first U-shaped slide rail 3 form a row distribution, such as Figure 1 As shown, the first to sixth rows are included, and the cells perpendicular to the second U-shaped slide rail 7 are arranged in a column. Figure 1 The following table includes the first to third columns, namely Figure 1 The cells are arranged in a 6×3 row and column array. For the cells arranged in rows, the initial ventilation channel is the ventilation channel close to the second U-shaped rail 7, and the cells in the first row are the cells close to the second U-shaped rail 7. For the cells arranged in columns, the initial ventilation channel is the ventilation channel away from the first U-shaped rail 3, and the cells in the first column are the cells away from the first U-shaped rail 3.

[0038] Assume that when the first movable fan 4 reaches the initial ventilation channel along the first U-shaped slide rail 3, the temperature sensors W1 to Wn and the gas sensors in the light control circuit at the initial ventilation channel detect an abnormality, and the first movable fan 4 continues to move to the next ventilation channel along the first U-shaped slide rail 3. If the temperature sensors W1 to Wn and the gas sensors in the light control circuit at the ventilation channel still detect an abnormality, the cells distributed in the first row are located to have an abnormality. Among them, if the temperature sensor in the light control circuit at the initial ventilation channel detects an abnormal temperature during the detection process, it means that there may be thermal runaway cells around the temperature sensor. At this time, it is considered that abnormal gas may appear in the initial ventilation channel, and the gas sensor will be turned on to detect whether there is abnormal gas in the initial ventilation channel. If there is abnormal gas, the cells on both sides of the initial ventilation channel may have thermal runaway. If there is no abnormal gas, the cells on both sides of the initial ventilation channel will not have thermal runaway. Similarly, the next ventilation channel is detected. If the gas sensors of the initial ventilation channel and the next ventilation channel both detect abnormal gas, the cells located between the two ventilation channels, i.e., the cells distributed in the first row, may have thermal runaway.

[0039] Similarly, when the second movable fan 8 reaches the initial ventilation channel along the second U-shaped slide rail 7, the temperature sensors W1 to Wn and the gas sensor in the light control circuit at the initial ventilation channel detect an abnormality, and the second movable fan 8 continues to move along the second U-shaped slide rail 7 to the next ventilation channel. If the temperature sensors W1 to Wn and the gas sensor in the light control circuit at the ventilation channel still detect an abnormality, the battery cells located between the two ventilation channels, i.e., the battery cells distributed in the first column, may experience thermal runaway, and the detection process is similar to that of the battery cells distributed in the rows, and will not be repeated here.

[0040] Taking into account the possibility that the battery cells distributed in the first row may experience thermal runaway and the battery cells distributed in the first column may experience thermal runaway, it can be finally located that the battery cells distributed in the first row and the first column have thermal runaway.

[0041] Through repeated detection of the entire cycle mentioned above, the moving trajectory of the movable fan realizes the alternation and delayed opening of the temperature sensor and the gas sensor in turn; the ventilation channel where the movable fan stops may contain the gas released by the early thermal runaway battery cells in other places and the diffused temperature, so the movable fan will stay for a period of time when it moves to the ventilation channel position, and the light control circuit will be delayed to open, first blow away the abnormal gas diffused from other places, and dissipate the heat, and then the temperature sensor and gas sensor in the light control circuit will be officially turned on to detect the thermal runaway temperature and thermal runaway abnormal gas of the battery cells on both sides of the ventilation channel. The abnormal signals detected by the temperature sensors and gas sensors corresponding to the two movable fans can accurately locate the position of the thermal runaway battery cells. The embodiment of the present invention can detect the thermal runaway problem of the battery cells of the lithium battery module in real time, and can quickly detect the thermal runaway of the battery cells, and locate the position of the thermal runaway battery cells.

[0042] In summary, the battery cell thermal runaway detection system of the lithium battery module proposed in the embodiment of the present invention can be used to quickly detect battery thermal runaway and locate the position of the thermal runaway battery cell. Specifically: the first slide bar 1 and the first screw nut transmission device 5 at both ends of the first U-shaped slide rail 3 can control the first U-shaped slide rail 3 to move up and down, thereby driving the first movable fan 4 to move up and down. Similarly, the second slide bar 6 and the second screw nut transmission device 9 at both ends of the second U-shaped slide rail 7 can control the second U-shaped slide rail 7 to move up and down, thereby driving the second movable fan 8 to move up and down. The upper and lower positions of the first movable fan 4 and the second movable fan 8 can be changed, and the all-round detection of thermal runaway gas of the lithium battery is achieved while uniformly dissipating heat; the first movable fan 4 and the second movable fan 8 can be changed. The movable fan 8 moves on the first U-shaped slide rail 3 and the second U-shaped slide rail 7 respectively. When the two movable fans move to each ventilation channel respectively, since both movable fans carry LED lights, the LED lights will trigger the light control circuit at the ventilation channel, and then the gas sensor in the light control circuit performs thermal runaway abnormality detection, locates the row and column where the thermal runaway battery cell is located, and quickly locates the position of the thermal runaway battery cell according to the row and column where the thermal runaway battery cell is located, and the movable wind shield 10 closes the ventilation channel perpendicular to the wind direction, so that the thermal runaway gas is quickly transmitted to the gas sensor, speeding up the thermal runaway detection speed; the embodiment of the present invention makes the signal received by the gas sensor more accurate through light control and delay, and effectively saves the power supply energy of the sensor. In general, the embodiment of the present invention can achieve rapid detection and precise positioning of the position of the thermal runaway battery cell through the coordinated work of the light control circuit, the movable wind shield and the movable fan.

[0043] Furthermore, the light control circuit of the embodiment of the present invention is as follows Figure 4As shown, it includes a photoresistor RG, a sliding rheostat RP, transistors Q1 to Q3, a capacitor C1, a gas sensor W, a temperature sensor W1 to Wn, a resistor R1 to R3, an electromagnet M1, an electromagnetic switch K1 and a selection switch K2; wherein, one end of the photoresistor RG is connected to the base of the transistor Q1 and one end of the sliding rheostat RP, and the other end of the photoresistor RG, the collector of the transistor Q1, one end of the electromagnet M1, one end of the electromagnetic switch K1, and one end of the resistor R3 are connected to a power supply VDD, for example, the voltage of the power supply VDD can be 5V, and the other end of the sliding rheostat RP, one end of the capacitor C1, the emitter of the transistor Q2, the emitter of the transistor Q3, One end of the temperature sensor W1 to the temperature sensor Wn is grounded GND, the other end of the capacitor C1 is connected to one end of the resistor R1 and the emitter of the transistor Q1, the other end of the resistor R1 is connected to the base of the transistor Q2, the collector of the transistor Q2 is connected to the other end of the electromagnet M1, the other end of the electromagnetic switch K1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the base of the transistor Q3 and one end of the selection switch K2, the other end of the selection switch K2 is connected to the other end of any selected temperature sensor from the temperature sensor W1 to the temperature sensor Wn, the other end of the resistor R3 is connected to one end of the gas sensor W, and the other end of the gas sensor W is connected to the collector of the transistor Q3. Figure 1 Mark 2 is the selection switch K2.

[0044] Furthermore, in the embodiment of the present invention, the first screw-nut transmission device 5, the second screw-nut transmission device 9 and the first slide bar 1 and the second slide bar 6 are all fixedly installed on the lower surface of the lithium battery module, and the fixing method may be glue bonding, screw connection, etc.; the first screw-nut transmission device 5 is installed parallel to the first slide bar 1, the second screw-nut transmission device 9 is installed parallel to the second slide bar 6, the first U-shaped slide rail 3 is perpendicular to the first screw-nut transmission device 5 and the first slide bar 1, and the second U-shaped slide rail 7 is perpendicular to the second screw-nut transmission device 9 and the second slide bar 6.

[0045] Furthermore, the first screw nut transmission device 5 and the second screw nut transmission device 9 of the embodiment of the present invention have the same structure; the first screw nut transmission device 5 is as follows: Figure 5 As shown, it includes a first micro motor 15, a first micro reducer 16, a lead screw 14 and a nut 13; wherein the first micro motor 15 and the first micro reducer 16 are fixedly mounted on the lower surface of the lithium battery module, the first micro motor 15 is connected to the first micro reducer 16, and the first micro reducer 16 drives the lead screw 14 to rotate, so that the first U-shaped slide rail 3 connected to the nut 13 moves up and down. Figure 5The structure shown can control the two U-shaped slide rails to move in the vertical direction through a set of screw nut transmission devices and slide rails, thereby ensuring that the two movable fans are located at the upper and lower layers of the lithium battery module respectively to avoid mutual interference caused by the two airflows when the two movable fans are at the same height position.

[0046] Furthermore, the first movable fan 4 and the second movable fan 8 in the embodiment of the present invention have the same structure; the first movable fan 4 is as shown in FIG. Figure 6 As shown, it includes a second micro motor 21, a second micro reducer 19, a fan 17 and a pulley 20; wherein the fan 17 is mounted on the second micro motor 21, the second micro motor 21 is connected to the second micro reducer 19, the LED lamp 18 is mounted on the second micro reducer 19, and the second micro reducer 19 drives the pulley 20 to slide, so that the first movable fan 4 moves horizontally on the first U-shaped slide rail 3; similarly, using Figure 6 In the structure shown, the second movable fan 8 can move horizontally on the first U-shaped slide rail 7. Figure 6 The structure shown can control the two movable fans to move horizontally on the corresponding U-shaped slide rails through the pulley 20.

[0047] Furthermore, the light control circuit provided at each ventilation channel of the embodiment of the present invention can sense the change of light through the photoresistor, and then control the corresponding temperature sensor and gas sensor to turn on. The light control circuit is composed of a photoresistor RG, multiple temperature sensors (W1-Wn), a gas sensor W1, three transistors (Q1, Q2, Q3), a capacitor C1, a sliding rheostat RP, three fixed resistors (R1, R2, R3), an electromagnetic switch K1 controlled by an electromagnet M1, and a selection switch K2. Among them, the photoresistor RG is installed on the side wall of the lithium battery module opposite to the corresponding ventilation channel, and its resistance value decreases with the increase of light intensity; the gas sensor W is installed at the end of the corresponding ventilation channel; the sliding rheostat RP, transistor Q1~transistor Q3, capacitor C1, resistor R1~resistor R3, electromagnet M1, electromagnetic switch K1, and selection switch K2 are integrated and installed on the lower surface of the lithium battery module at the corresponding ventilation channel; the temperature sensor W1~temperature sensor Wn are installed on the surface of the corresponding battery cell 12, and two temperature sensors are installed on the surface of each battery cell 12, one temperature sensor is used in the light control circuit set at the corresponding ventilation channel of the row distribution, and the other temperature sensor is used in the light control circuit set at the corresponding ventilation channel of the column distribution. The temperature sensor on the battery cell 12 distributed in a row and the temperature sensor on the battery cell 12 distributed in a column respectively constitute the temperature sensor W1~temperature sensor Wn in their respective light control circuits. The detection process of the battery cells 12 distributed in rows: select the temperature sensor corresponding to a certain battery cell in the row from the temperature sensors W1 to Wn corresponding to each row through the selection switch K2 and connect it to the light control circuit; similarly, the detection process of the battery cells 12 distributed in columns: select the temperature sensor corresponding to a certain battery cell in the column from the temperature sensors W1 to Wn corresponding to each column through the selection switch K2 and connect it to the light control circuit. Among them, n represents the number of battery cells 12 distributed in rows or columns, and the value of n is determined according to the actual situation. The subscript n represents the temperature sensor set on the nth battery cell distributed in rows or columns. The figure shows the case of n=4, indicating that the number of battery cells 12 distributed in rows or columns is 4, and the temperature sensors corresponding to the rows or columns on these four battery cells are recorded as W1~W4 respectively. It can be seen that for the lithium battery module, the battery cells 12 distributed in rows and columns are respectively designed with corresponding light control circuits, so that the simultaneous detection of the row and column channels of the battery cells 12 can be achieved during the detection process.

[0048] In each light control circuit of the embodiment of the present invention, the selection switch K2 is as follows: Figure 7As shown, it includes a rotating component 23, a third micro motor 25, a third micro reducer 24 and a base 26; wherein the base 26 is fixedly installed on the lower surface of the lithium battery module at the ventilation channel corresponding to the light control circuit, and the third micro motor 25 is installed on the base 26, and the third micro motor 25 is connected to the third micro reducer 24, and the third micro reducer 24 drives the rotating component 23 to rotate, so that the rotating component 23 can select to connect to any temperature sensor among the temperature sensors W1 to Wn; wherein the sliding rheostat RP, transistors Q1 to Q3, capacitor C1, resistors R1 to R3, electromagnet M1, and electromagnetic switch K1 are integrated and installed in the base 26. It can be seen that the embodiment of the present invention utilizes Figure 7 The structure shown can select corresponding temperature sensors from the battery cells 12 distributed in rows or columns and connect them to the light control circuit, so as to achieve more comprehensive detection of the battery cells during the detection process. Figure 4 M in the figure is the third micro motor 25 .

[0049] Furthermore, in the embodiment of the present invention, an air outlet 11 is arranged around the gas sensor W installed at the end of each ventilation channel, and the structure is as follows: Figure 8 As shown; wherein, when the first movable fan 4 and the second movable fan 8 pass through the corresponding ventilation channel, the wind direction is directly facing the gas sensor W and flows out through the surrounding air outlet 11 around the gas sensor W. Figure 8 The reference numeral 22 is a gas sensor W.

[0050] In the embodiment of the present invention, two temperature sensors are arranged on each battery cell 12. Fig. 9 As shown, the resistance value of the electrode located on one side of each battery cell 12 close to the electrode ear increases with the increase of temperature. Fig. 9 The reference numeral 27 is a temperature sensor.

[0051] In the embodiment of the present invention, each movable wind shield 10 disposed on the battery cell includes an upper movable wind shield and a lower movable wind shield, and the upper movable wind shield and the lower movable wind shield can both close the ventilation channel perpendicular to the upper movable wind shield according to the wind direction. The upper movable wind shield and the lower movable wind shield have the same structure; the upper movable wind shield and the lower movable wind shield are as follows: Fig.10 The windshield A surface 30, the central axis 28 and the windshield B surface 29 are shown. The windshield B surface 29 is fixedly mounted on the surface of the corresponding battery cell 12. The windshield A surface 30 rotates around the central axis 28 with the flow of gas to close the ventilation channel perpendicular to the wind direction. The windshield B surface 29 is fixedly mounted on the surface of the battery cell 12 by screw connection or the like. Fig.10In the structure shown, during the detection process, as the movable fan moves up and down, the upper and lower movable wind shields are controlled to close the ventilation channel perpendicular to the wind direction, so that the thermal runaway gas can be quickly transmitted to the gas sensor, so that the gas sensor can more accurately detect the thermal runaway gas signal caused by thermal runaway, thereby quickly locating the position of the thermal runaway battery cell.

[0052] Fig.11 and Fig.12 The gas flow mode between the battery cells distributed in rows and columns is illustrated. For such gas flow conditions, the system provided in the embodiments of the present invention can fully detect them.

[0053] based on Figure 4 The light control circuit shown in the embodiment of the present invention utilizes Figure 1 The system shown in the figure also includes the following steps for detecting thermal runaway of a battery cell:

[0054] During the movement, when the LED light 18 is driven by the movable fan to irradiate the photoresistor RG, the resistance of the photoresistor RG decreases, the transistor Q1 is turned on, and the capacitor C1 starts to be charged through the transistor Q1, and the base voltage of the transistor Q2 starts to rise; wherein the movable fan includes a first movable fan 4 and a second movable fan 8;

[0055] When the base voltage of transistor Q2 rises to the set voltage threshold value, transistor Q2 starts to conduct. At this time, the current flowing through transistor Q2 is still small and insufficient to activate electromagnet M1. As the charging voltage of capacitor C1 gradually rises, the current flowing through transistor Q2 also increases, causing electromagnet M1 to activate. Under the action of electromagnet M1, electromagnetic switch K1 is closed, and selection switch K2 starts to work, so that temperature sensors W1 to Wn are connected to the circuit in sequence. Among them, during the movement of the first movable fan 4, the selection switch K2 selects the temperature sensor at the corresponding ventilation channel from the temperature sensors W1 to Wn distributed in the row to be connected to the light control circuit. Similarly, during the movement of the second movable fan 8, the selection switch K2 selects the temperature sensor at the corresponding ventilation channel from the temperature sensors W1 to Wn distributed in the column to be connected to the light control circuit.

[0056] When the temperature detected by the temperature sensors connected in sequence reaches the set temperature threshold value, transistor Q3 is turned on and the gas sensor W is turned on;

[0057] When the light irradiated by the LED lamp 18 on the photoresistor RG gradually weakens until it stops, the resistance of the photoresistor RG increases, and the transistor Q1 is turned off; the transistor Q2 continues to be turned on for a period of time during the discharge of the capacitor C1; when the voltage on the capacitor C1 is not enough to turn on the transistor Q2, the electromagnet M1 is disconnected, and without the action of the electromagnet M1, the electromagnetic switch K1 is disconnected, and the temperature sensor W1~temperature sensor Wn and the gas sensor W are all turned off.

[0058] In the embodiment of the present invention, the light intensity required for the transistor Q1 to be turned on can be changed by adjusting the sliding rheostat RP; the discharge time of the capacitor C1 can be adjusted by changing the product of the capacitor C1 and the fixed resistor R1; the voltage threshold value set by the base voltage of the transistor and the temperature threshold value set by the temperature sensor can be set according to actual conditions.

[0059] based on Figure 4 The designed light control circuit can realize the following functions: when the fan 17 blows away the abnormal gas and heat diffused from other places, the light control circuit is turned on, and the temperature sensor is used to detect whether thermal runaway may occur. If so, the gas sensor is turned on for further judgment to improve the accuracy of thermal runaway detection. If not, the gas sensor remains closed. This judgment method can avoid the problem that when the temperature sensor threshold value is too high, thermal runaway has occurred when the temperature sensor detects the signal, and when the temperature sensor threshold value is too low, the detection signal is interfered. In addition, the temperature sensor and gas sensor on the ventilation channel are turned on only after the movable fan reaches the ventilation channel, which can save the power supply time of the sensor and extend the service life of the sensor. The embodiment of the present invention not only realizes the temperature sensor and gas sensor on the corresponding ventilation channel to be turned on and off alternately in sequence through the light control circuit, but also avoids the energy waste of the temperature sensor and gas sensor being turned on for a long time. At the same time, the temperature sensor and gas sensor are turned on / off alternately in sequence according to the moving trajectory of the movable fan, which avoids the misdetection and misjudgment of thermal runaway caused by the heat and gas diffused from other places to the corresponding ventilation channel, and improves the positioning accuracy of the thermal runaway lithium battery.

[0060] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0061] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the specification and its drawings. In the specification, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude multiple situations. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0062] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A lithium battery module thermal runaway detection system, characterized in that: The system comprises: A lithium battery module, wherein a plurality of battery cells are arranged in rows and columns in the lithium battery module, and a light control circuit is arranged at the ventilation passage between adjacent battery cells, the light control circuit includes a gas sensor, and a movable wind shield is arranged on each battery cell; a first U-shaped slide rail and a second U-shaped slide rail, wherein the first U-shaped slide rail and the second U-shaped slide rail are adjacent and vertically arranged, the first U-shaped slide rail is arranged on one side of all battery cells arranged in rows, and the second U-shaped slide rail is arranged on one side of all battery cells arranged in columns, a first slide rod and a first lead screw nut transmission device are arranged at both ends of the first U-shaped slide rail, a second slide rod and a second lead screw nut transmission device are arranged at both ends of the second U-shaped slide rail, and a first movable fan carrying an LED lamp is arranged on the first U-shaped slide rail, and a second movable fan carrying an LED lamp is arranged on the second U-shaped slide rail; wherein the process of detecting thermal runaway of battery cells using the system includes: During the movement of the first movable fan, when the first movable fan reaches a certain ventilation channel along the first U-shaped slide rail, the first movable fan stays at the ventilation channel, blows away the abnormal thermal runaway gas diffused from other places in the early stage, and dissipates the heat, then the light control circuit arranged at the ventilation channel is turned on, at this time the movable wind shield plate at the ventilation channel is parallel to the wind direction, if the gas sensor in the light control circuit arranged at the ventilation channel receives a thermal runaway gas signal, then there are battery cells on both sides of the ventilation channel in a thermal runaway state; the first movable fan continues to move to the next ventilation channel, at this time the light control circuit arranged at the previous ventilation channel is turned off, and the light control circuit arranged at the current ventilation channel is turned on, if the gas sensor arranged at the current ventilation channel still receives a thermal runaway gas signal, then the row where the battery cell in a thermal runaway state is located is located; During the movement of the second movable fan, when the second movable fan reaches a certain ventilation channel along the second U-shaped slide rail, the second movable fan stays at the ventilation channel, blows away the abnormal thermal runaway gas diffused from other places in the early stage, and after the heat is dissipated, the light control circuit arranged at the ventilation channel is turned on. At this time, the movable wind shield plate at the ventilation channel is parallel to the wind direction. If the gas sensor in the light control circuit arranged at the ventilation channel receives a thermal runaway gas signal, then there are battery cells on both sides of the ventilation channel in a thermal runaway state; the second movable fan continues to move to the next ventilation channel, at this time the light control circuit arranged at the previous ventilation channel is turned off, and the light control circuit arranged at the current ventilation channel is turned on. If the gas sensor arranged at the current ventilation channel still receives a thermal runaway gas signal, then the column where the battery cells in a thermal runaway state are located is located; The battery cell in the thermal runaway state is located according to the row and column where the battery cell in the thermal runaway state is located.

2. The battery cell thermal runaway detection system of the lithium battery module according to claim 1, characterized in that: The first screw-nut transmission device and the second screw-nut transmission device have the same structure; the first screw-nut transmission device includes a first micro motor, a first micro reducer, a screw and a nut; wherein, The first micro motor and the first micro reducer are both fixedly mounted on the lower surface of the lithium battery module. The first micro motor is connected to the first micro reducer, and the first micro reducer drives the lead screw to rotate so that the first U-shaped slide rail connected to the nut moves up and down.

3. The battery cell thermal runaway detection system of the lithium battery module according to claim 1, characterized in that: The first movable fan and the second movable fan have the same structure; the first movable fan comprises a second micro motor, a second micro reducer, a fan and a pulley; wherein, The fan is installed on the second micro motor, the second micro motor is connected to the second micro reducer, the LED lamp is installed on the second micro reducer, and the second micro reducer drives the pulley to slide so that the first movable fan moves horizontally on the first U-shaped slide rail.

4. The thermal runaway detection system for a lithium battery module according to claim 1, characterized in that: Each movable windshield provided on the battery cell includes an upper movable windshield and a lower movable windshield; the upper movable windshield and the lower movable windshield have the same structure; the upper movable windshield includes a windshield A surface, a central axis and a windshield B surface; wherein, The windshield B surface is fixedly mounted on the surface of the corresponding battery cell; the windshield A surface rotates around the central axis along with the flow of gas to close the ventilation channel perpendicular to the wind direction.

5. The battery cell thermal runaway detection system of the lithium battery module according to claim 1, characterized in that: Two temperature sensors are installed on the surface of each battery cell, one temperature sensor is used in the light control circuit arranged at the corresponding ventilation channel of the row distribution, and the other temperature sensor is used in the light control circuit arranged at the corresponding ventilation channel of the column distribution.

6. The battery cell thermal runaway detection system of the lithium battery module according to claim 1, characterized in that: Each light control circuit includes a photoresistor RG, a sliding rheostat RP, transistors Q1 to Q3, a capacitor C1, a gas sensor W, a temperature sensor W1 to Wn, a resistor R1 to R3, an electromagnet M1, an electromagnetic switch K1 and a selection switch K2; wherein, One end of the photoresistor RG is connected to the base of the transistor Q1 and one end of the sliding rheostat RP. The other end of the photoresistor RG, the collector of the transistor Q1, one end of the electromagnet M1, one end of the electromagnetic switch K1, and one end of the resistor R3 are connected to the power supply VDD. The other end of the sliding rheostat RP, one end of the capacitor C1, the emitter of the transistor Q2, the emitter of the transistor Q3, and one end of the temperature sensor W1 to the temperature sensor Wn are all grounded GND. The other end of the capacitor C1 is connected to one end of the resistor R1 and the emitter of the transistor Q1. The other end of the resistor R1 is connected to the base of the transistor Q2, the collector of the transistor Q2 is connected to the other end of the electromagnet M1, the other end of the electromagnetic switch K1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the base of the transistor Q3 and one end of the selection switch K2, the other end of the selection switch K2 is connected to the other end of any selected temperature sensor from the temperature sensor W1 to the temperature sensor Wn, the other end of the resistor R3 is connected to one end of the gas sensor W, and the other end of the gas sensor W is connected to the collector of the transistor Q3.

7. The lithium battery module thermal runaway detection system according to claim 6, characterized in that: In the light-controlled circuit arranged at each ventilation channel, the photoresistor RG is installed on the side wall of the lithium battery module opposite to the corresponding ventilation channel, the temperature sensors W1 to Wn are installed on the surface of the corresponding battery cell, the gas sensor W is installed at the end of the corresponding ventilation channel, and the sliding rheostat RP, transistors Q1 to Q3, capacitor C1, resistors R1 to R3, electromagnet M1, electromagnetic switch K1, and selection switch K2 are integrated and installed on the lower surface of the lithium battery module at the corresponding ventilation channel.

8. The battery cell thermal runaway detection system of the lithium battery module according to claim 6, characterized in that: An air outlet is arranged around the gas sensor W installed at the end of each ventilation channel; wherein, When the first movable fan and the second movable fan pass through the corresponding ventilation channels, the wind direction faces the gas sensor W and flows out through the air outlet around the gas sensor W.

9. The lithium battery module thermal runaway detection system according to claim 6, characterized in that: The selection switch K2 in each light control circuit includes a rotating component, a third micro motor, a third micro reducer and a base; wherein, The base is fixedly installed on the lower surface of the lithium battery module at the ventilation channel corresponding to the light control circuit. The third micro motor is installed on the base. The third micro motor is connected to the third micro reducer. The third micro reducer drives the rotating component to rotate so that the rotating component can select to connect to any one of the temperature sensors W1 to Wn; wherein, the sliding rheostat RP, transistors Q1 to Q3, capacitor C1, resistors R1 to R3, electromagnet M1, and electromagnetic switch K1 are integrated and installed in the base.

10. The lithium battery module thermal runaway detection system according to claim 6, characterized in that: The process of using the system to detect thermal runaway of a battery cell also includes: During the movement, when the LED light shines on the photoresistor RG driven by the movable fan, the resistance of the photoresistor RG decreases, the transistor Q1 is turned on, the capacitor C1 starts to be charged through the transistor Q1, and the base voltage of the transistor Q2 starts to rise; wherein, the movable fan includes the first movable fan and the second movable fan; When the base voltage of transistor Q2 rises to the set voltage threshold value, transistor Q2 starts to conduct. At this time, the current flowing through transistor Q2 is not enough to activate electromagnet M1. As the charging voltage of capacitor C1 gradually rises, the current flowing through transistor Q2 also increases, causing electromagnet M1 to activate. Electromagnet switch K1 closes, and selector switch K2 starts to work, so that temperature sensors W1 to Wn are connected to the light control circuit in sequence. When the temperature detected by the temperature sensors connected in sequence reaches the set temperature threshold value, the transistor Q3 is turned on and the gas sensor W is turned on, otherwise the gas sensor W remains turned off; When the light irradiated by the LED lamp on the photoresistor RG gradually weakens until it stops, the resistance of the photoresistor RG increases and the transistor Q1 is cut off; the transistor Q2 continues to be turned on for a period of time during the discharge of the capacitor C1; when the voltage on the capacitor C1 is not enough to make the transistor Q2 turn on, the electromagnet M1 is disconnected, the electromagnetic switch K1 is disconnected, and the temperature sensor W1~temperature sensor Wn and the gas sensor W are all turned off.

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