Battery pack liquid leakage detection sensor

Abstract

The utility model discloses a battery pack liquid leakage detection sensor which comprises a circuit substrate used for being assembled on a battery pack, a first detection circuit and a second detection circuit which are used for being connected with a detection circuit are borne on the back face of the circuit substrate, and the first detection circuit and the second detection circuit are close to each other but do not make contact with each other. The first detection circuit comprises a first main circuit and a plurality of first branch circuits, the second detection circuit comprises a second main circuit and a plurality of second branch circuits, the first main circuit basically surrounds the second detection circuit, and a detection area is defined by the first main circuit and the second detection circuit; the first branch lines are located on the inner side of the first main line, and the first branch lines and the second branch lines are sequentially arranged at intervals in a staggered mode. According to the invention, the circuit can be arranged more tightly, so that liquid leakage detection can be realized as long as a small amount of electrolyte is in contact with the detection area, and the detection precision is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and in particular to a battery pack leakage detection sensor. Background Technology

[0002] With the rapid development of energy storage technology, batteries are being used more and more widely, thus placing increasingly higher demands on battery safety and reliability. During battery use, problems such as severe overcharging, short circuits, severe overheating, thermal runaway, impact or crushing deformation, and punctures can occur. These problems may cause the internal temperature and pressure of the battery to rise continuously, and when they exceed its inherent safety threshold, the battery may explode.

[0003] The battery explosion-proof valve is the last line of defense against explosions. When the internal pressure of the battery reaches the opening threshold of the safety valve (for example, the opening threshold of a lithium-ion battery safety valve is typically 600–800 kPa), the battery explosion-proof valve opens to release pressure and prevent the battery from exploding. However, when the battery explosion-proof valve opens, it signifies a serious safety problem. Therefore, it is necessary to check the battery when the explosion-proof valve is open to prevent the accident from escalating.

[0004] When the battery explosion-proof valve is opened, electrolyte will be splashed out at the same time. Since the electrolyte is conductive, the conductivity of the electrolyte can be used to detect leakage, and thus to detect the opening of the explosion-proof valve. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a battery pack leakage detection sensor, which has the advantage of effectively realizing leakage detection.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] According to an embodiment of this disclosure, a battery pack leakage detection sensor is provided, including a circuit board for mounting on a battery pack. The back side of the circuit board carries a first detection line and a second detection line for connection with a detection circuit. The first detection line and the second detection line are close to each other but do not contact each other.

[0008] The first detection line includes a first main line and multiple first branch lines connected to the first main line. The second detection line includes a second main line and multiple second branch lines connected to the second main line. The first main line basically surrounds the second detection line and forms a detection area. The first branch lines are located inside the first main line, and each first branch line and each second branch line are arranged alternately and sequentially. The first branch lines and second branch lines are densely distributed in the detection area. The second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line.

[0009] One end of the first main line has a first connecting pin, and the second main line extends out of the first main line and has a second connecting pin. The first connecting pin and the second connecting pin are connected to the detection circuit. When the detection area comes into contact with electrolyte, the resistance between the first detection line and the second detection line changes to change the resistance value of the detection circuit and form a detection signal.

[0010] To achieve the above technical solution, during use, the circuit board is assembled onto the battery pack and corresponds to the explosion-proof valve. When a battery malfunctions and causes the explosion-proof valve to open, electrolyte will splash outwards onto the detection area. The electrolyte will cause a change in the resistance impedance between the first and second detection lines, thereby changing the equivalent resistance value of the sensor connected in parallel to the detection circuit. This, in turn, causes a change in the voltage signal in the detection circuit, forming a detection signal. Leakage detection can be achieved through this detection signal. Since the first main line surrounds the second detection line to form a detection area, and the first and second branch lines are densely distributed within the detection area, when electrolyte comes into contact with any position within the detection area, an impedance change between the first and second detection lines can be achieved, improving detection efficiency and detection effect. Furthermore, the arrangement of the first and second branch lines allows for a more compact circuit arrangement, enabling leakage detection even when only a small amount of electrolyte comes into contact with the detection area, thus improving detection accuracy.

[0011] In some exemplary embodiments, the second main line is linear and located at the central axis of the first main line, and multiple second branch lines are symmetrically arranged on both sides of the second main line. One end of the second branch line is connected to the second main line, and the other end extends close to the first main line.

[0012] In some exemplary embodiments, the second main line is oblong in shape, and the central axis of the second main line is consistent with the central axis of the first main line. Multiple second branch lines are symmetrically arranged on both sides of the second main line, with one end of the second branch line connected to the second main line and the other end extending close to the first main line.

[0013] In some exemplary embodiments, the first main line is elliptical, and multiple first branch lines are symmetrically arranged along the long axis of the first main line. One end of each first branch line is connected to the first main line, and the other end extends to a point close to the second main line.

[0014] In some exemplary embodiments, the detection circuit includes a detection resistor, with the first and second connection pins connected in parallel with the detection resistor to change the resistance value of the detection circuit when the detection area comes into contact with the electrolyte.

[0015] By implementing the above technical solution, when the detection area comes into contact with the electrolyte, the impedance between the first detection line and the second detection line can be changed. At the same time, the change in resistance value is made more obvious through the parallel detection resistor, thus realizing leakage detection and improving detection accuracy.

[0016] In some exemplary embodiments, when the circuit board is mounted on the battery pack, the detection area corresponds to the explosion-proof valve, and the distance between the circuit board and the explosion-proof valve is 1-3 mm.

[0017] To achieve the above technical solution, by reasonably setting the distance between the circuit board and the explosion-proof valve, it is possible to ensure that the electrolyte can splash onto the detection area when the valve is opened.

[0018] In some exemplary embodiments, the circuit board is a rigid PCB or a flexible FPC.

[0019] In summary, compared with the prior art, this utility model has the following beneficial effects:

[0020] This utility model embodiment provides a battery pack leakage detection sensor. In use, the circuit board is assembled onto the battery pack and corresponds to the explosion-proof valve. When a battery malfunctions and causes the explosion-proof valve to open, electrolyte will splash outward onto the detection area. The electrolyte will cause a change in the resistance impedance between the first and second detection lines, thereby changing the equivalent resistance value of the sensor connected in parallel to the detection circuit. This, in turn, causes a change in the voltage signal in the detection circuit, forming a detection signal. Leakage detection can be achieved through this detection signal. Since the first main line surrounds the second detection line to form the detection area, and the first and second branch lines are densely distributed within the detection area, when electrolyte comes into contact with any position within the detection area, an impedance change between the first and second detection lines can be achieved, improving detection efficiency and detection effect. Furthermore, the arrangement of the first and second branch lines allows for a more compact circuit arrangement, enabling leakage detection even when only a small amount of electrolyte comes into contact with the detection area, thus improving detection accuracy. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present utility model.

[0022] Figure 2 This is a schematic diagram of the detection circuit in Embodiment 1 of this utility model.

[0023] Figure 3 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0024] The numbers and letters in the figure represent the corresponding component names:

[0025] 10. Circuit board; 20. First detection line; 21. First main line; 22. First branch line; 23. First connecting pin; 30. Second detection line; 31. Second main line; 32. Second branch line; 33. Second connecting pin; 40. Detection circuit; 41. Detection resistor. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Example 1

[0028] like Figure 1 and Figure 2As shown, this utility model embodiment provides a battery pack leakage detection sensor, including a circuit board 10 for mounting on a battery pack. The back of the circuit board 10 carries a first detection line 20 and a second detection line 30 for connection with a detection circuit 40. The first detection line 20 and the second detection line 30 are close to each other but do not contact each other.

[0029] Specifically, the first detection line 20 and the second detection line 30 are set on the circuit board 10 by etching. The circuit board can be a rigid PCB or a flexible FPC, which can be selected according to actual needs to meet different usage requirements. The first detection line 20 includes a first main line 21 and multiple first branch lines 22 connected to the first main line 21. The second detection line 30 includes a second main line 31 and multiple second branch lines 32 connected to the second main line 31. The first main line 21 basically surrounds the second detection line 30 and forms a detection area. The first branch lines 22 are located inside the first main line 21, and each first branch line 22 and each second branch line 32 are arranged alternately and sequentially. The first branch lines 22 and the second branch lines 32 are densely distributed in the detection area. The second main line 31 is located in the middle of the detection area, and the second branch lines 32 are located on both sides of the second main line 31.

[0030] One end of the first main line 21 has a first connecting pin 23. The second main line 31 extends from the first main line 21 and has a second connecting pin 33. The first connecting pin 23 and the second connecting pin 33 are connected to the detection circuit 40. When the detection area comes into contact with electrolyte, the resistance between the first detection line 20 and the second detection line 30 changes to change the resistance value of the detection circuit 40 and form a detection signal.

[0031] The first main line 21 is elliptical in shape, and multiple first branch lines 22 are symmetrically arranged along the long axis of the first main line 21. One end of the first branch line 22 is connected to the first main line 21, and the other end extends to the vicinity of the second main line 31. An opening is provided on one side of the first main line 21, so that the first main line 21 forms a free connection end. The first connecting leg 23 is connected to any of the free connection ends, and the second connecting leg 33 extends out of the first main line 21 through the opening.

[0032] The second main line 31 is linear and located at the central axis of the first main line 21. Specifically, the second main line 31 can be straight or wavy. In this embodiment, the second main line 31 is set to be straight. Multiple second branch lines 32 are symmetrically arranged on both sides of the second main line 31. One end of the second branch line 32 is connected to the second main line 31, and the other end extends close to the first main line 21.

[0033] The detection circuit 40 includes a detection resistor 41. The first connecting pin 23 and the second connecting pin 33 are connected in parallel with the detection resistor 41 to change the resistance value of the detection circuit 40 when the detection area comes into contact with the electrolyte. When the detection area comes into contact with the electrolyte, the impedance between the first detection line 20 and the second detection line 30 can be changed. At the same time, the parallel detection resistor 41 makes the change in resistance value more obvious, realizing leakage detection and improving detection accuracy.

[0034] In some embodiments, the detection resistor 41 may also be connected to several precision adjustment resistors to further adjust the detection accuracy. It is understood that the detection circuit 40 is connected to the central processing unit to upload the detection signal to the battery management system when the detection signal is generated.

[0035] In use, the circuit board 10 is mounted on the battery pack, the detection area corresponds to the explosion-proof valve, and the distance between the circuit board 10 and the explosion-proof valve is 1-3mm. By reasonably setting the distance between the circuit board 10 and the explosion-proof valve, it is possible to ensure that the electrolyte can splash onto the detection area when the valve is opened.

[0036] In use, the circuit board 10 is assembled onto the battery pack and corresponds to the explosion-proof valve. When a battery malfunctions and causes the explosion-proof valve to open, electrolyte will splash outwards onto the detection area. The electrolyte will cause a change in the resistance between the first detection line 20 and the second detection line 30, thereby changing the equivalent resistance value of the sensor connected in parallel to the detection circuit 40. This, in turn, causes a change in the voltage signal in the detection circuit 40, forming a detection signal. This detection signal can be used to detect leakage. When leakage is detected, it indicates that the explosion-proof valve has opened. Since the first main line 21 surrounds the second detection line 30 to form a detection area, and the first branch line 22 and the second branch line 32 are densely distributed within the detection area, when electrolyte comes into contact with any position within the detection area, an impedance change between the first detection line 20 and the second detection line 30 can be achieved, improving detection efficiency and detection effect. The arrangement of the first branch line 22 and the second branch line 32 allows for a more compact circuit arrangement, enabling leakage detection even when only a small amount of electrolyte comes into contact with the detection area, thus improving detection accuracy.

[0037] Example 2

[0038] The difference between this embodiment and Embodiment 1 is that: in this embodiment, as... Figure 3As shown, the second main line 31 is oblong, and the central axis of the second main line 31 is consistent with the central axis of the first main line 21. Multiple second branch lines 32 are symmetrically arranged on both sides of the second main line 31. One end of the second branch line 32 is connected to the second main line 31, and the other end extends close to the first main line 21. When the second main line 31 is oblong, it is easier to etch and form.

[0039] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of this utility model, and all of these fall within the protection scope of this utility model.

Claims

1. A battery pack leakage detection sensor, characterized in that, The circuit board includes a circuit board for mounting on a battery pack. The back of the circuit board carries a first detection line and a second detection line for connection with a detection circuit. The first detection line and the second detection line are close to each other but do not contact each other. The first detection line includes a first main line and multiple first branch lines connected to the first main line. The second detection line includes a second main line and multiple second branch lines connected to the second main line. The first main line basically surrounds the second detection line and forms a detection area. The first branch lines are located inside the first main line, and each first branch line and each second branch line are arranged alternately and sequentially. The first branch lines and second branch lines are densely distributed in the detection area. The second main line is located in the middle of the detection area, and the second branch lines are located on both sides of the second main line. One end of the first main line has a first connecting pin, and the second main line extends out of the first main line and has a second connecting pin. The first connecting pin and the second connecting pin are connected to the detection circuit. When the detection area comes into contact with electrolyte, the resistance between the first detection line and the second detection line changes to change the resistance value of the detection circuit and form a detection signal.

2. The battery pack leakage detection sensor according to claim 1, characterized in that, The second main line is linear and located at the central axis of the first main line. Multiple second branch lines are symmetrically arranged on both sides of the second main line. One end of the second branch line is connected to the second main line, and the other end extends close to the first main line.

3. The battery pack leakage detection sensor according to claim 1, characterized in that, The second main line is oblong in shape, and the central axis of the second main line is consistent with the central axis of the first main line. Multiple second branch lines are symmetrically arranged on both sides of the second main line. One end of the second branch line is connected to the second main line, and the other end extends close to the first main line.

4. The battery pack leakage detection sensor according to claim 2 or 3, characterized in that, The first main line is elliptical in shape, and multiple first branch lines are symmetrically arranged along the long axis of the first main line. One end of each first branch line is connected to the first main line, and the other end extends to a point close to the second main line.

5. The battery pack leakage detection sensor according to claim 1, characterized in that, The detection circuit includes a detection resistor, and the first and second connecting pins are connected in parallel with the detection resistor to change the resistance value of the detection circuit when the detection area comes into contact with the electrolyte.

6. The battery pack leakage detection sensor according to claim 1, characterized in that, When the circuit board is assembled on the battery pack, the detection area corresponds to the explosion-proof valve, and the distance between the circuit board and the explosion-proof valve is 1-3mm.

7. The battery pack leakage detection sensor according to claim 1, characterized in that, The circuit board is a rigid PCB or a flexible FPC.

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