Lithium battery single body internal short circuit detection device
By designing a lithium battery cell internal short circuit detection device that utilizes liquid nitrogen freezing environment and DC resistance detection, the problems of low detection accuracy and limited applicability in the prior art are solved, and efficient and accurate internal short circuit detection is achieved.
Patent Information
- Application Number
- CN202323516515.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2033-12-22
AI Technical Summary
The prior art has problems of limited applicability, low accuracy and low efficiency when detecting short circuits in lithium batteries, especially in the early stages of mild internal short circuits and detection of lithium iron phosphate batteries.
A lithium battery cell internal short circuit detection device was designed, which uses liquid nitrogen freezing environment to inactivate the internal electrolyte of the battery. It connects external testing equipment through the positive and negative electrode crimping seal rings, and combines DC resistance detection to accurately determine whether the battery exists inside. Short circuit.
It realizes efficient and accurate detection at different temperatures and battery systems, avoids dependence on the detection environment, improves detection efficiency and accuracy, and is suitable for internal short circuit detection of a single battery cell.
Smart Images
Figure CN222461646U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium battery monomer internal short circuit detection, and specifically relates to a lithium battery monomer internal short circuit detection device. Background Art
[0002] During the use of lithium-ion batteries, internal short circuits can cause a sharp drop in voltage, affecting the normal use and performance of the battery; shortening the battery life and reducing the battery's charge and discharge efficiency; and causing a large amount of Joule heat to be generated inside the battery, which may cause fires and explosions, or even trigger chain reactions that damage and endanger surrounding equipment and the environment. Therefore, it is imperative to implement reliable and efficient detection of battery internal short circuit faults to avoid personal or property losses. For example, patent CN114152826A discloses the detection methods for internal short circuit of lithium-ion batteries in the prior art, which can be roughly divided into the following categories: 1) Threshold method: by judging whether the battery voltage, temperature, voltage change rate or temperature change rate exceeds the preset threshold; 2) Power consumption method: the battery consumption is obtained through the SOC estimation process, and compared with the power used, that is, the battery leakage detection is obtained; 3) Remaining rechargeable capacity method: the leakage of the battery is judged by the difference between the remaining rechargeable capacity of two adjacent charging processes; 4) Comparative analysis method: for series battery packs, internal short circuit detection is achieved by comparing the consistency and correlation of the voltage or other parameters between the single cells; 5) Sensor measurement method: for parallel battery packs, internal short circuit detection can be achieved through a ring circuit topology structure and a circuit sensor. However, these methods still have some defects that limit their applicability or effectiveness. For example, the threshold method is difficult to identify early internal short circuits of a relatively mild degree and is limited by the layout of temperature sensors; the power consumption method is greatly affected by the accuracy of SOC estimation and is limited by the flat open-circuit voltage curve of lithium iron phosphate batteries, so the method is difficult to apply to lithium iron phosphate batteries; the remaining rechargeable capacity method needs to be carried out in a charging scenario, and is powerless against sudden internal short circuit failures under battery discharge operation; the comparative analysis method requires mutual comparison between battery cells and cannot be used in a single battery cell internal short circuit detection scenario; therefore, providing an internal short circuit detection method that is less restricted, more applicable, more accurate, and more efficient is a technical problem that needs to be urgently solved in this field. Utility Model Content
[0003] The purpose of the utility model is to provide a lithium battery monomer internal short circuit detection device to solve the above problems existing in the prior art.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A lithium battery cell internal short circuit detection device comprises a box body for placing a test battery and a box cover sealed and buckled on the upper end of the box body, a positive electrode crimping sealing ring connected to the positive electrode of an external test device and a negative electrode crimping sealing ring connected to the negative electrode of the external test device are installed on the box cover, the positive electrode crimping sealing ring is connected to a positive electrode U-shaped clip through a wire, and is used to connect the positive electrode pole of the test battery through the positive electrode U-shaped clip, and the negative electrode crimping sealing ring is connected to a negative electrode U-shaped clip through a wire, and is used to connect the negative electrode pole of the test battery through the negative electrode U-shaped clip; the box cover is provided with a liquid nitrogen guide port for introducing liquid nitrogen into the box body.
[0006] As a preferred technical solution in the utility model, a partition is provided in the box body, which is used to divide the internal space of the box body into a first groove for placing the test battery and a second groove for placing the test battery through the partition; the positive electrode crimping sealing ring includes a first positive electrode crimping sealing ring and a second positive electrode crimping sealing ring, the negative electrode crimping sealing ring includes a first negative electrode crimping sealing ring and a second negative electrode crimping sealing ring, the positive electrode U-shaped clip includes a first positive electrode U-shaped clip and a second positive electrode U-shaped clip, the negative electrode U-shaped clip includes a first negative electrode U-shaped clip and a second negative electrode U-shaped clip, the first positive electrode crimping sealing ring is connected to the first positive electrode U-shaped clip through a wire, Used to connect the positive electrode pole of the test battery located in the first groove through the first positive U-shaped clip; the second positive crimping sealing ring is connected to the second positive U-shaped clip through a wire, and is used to connect the positive electrode pole of the test battery located in the second groove through the second positive U-shaped clip; the first negative crimping sealing ring is connected to the first negative U-shaped clip through a wire, and is used to connect the negative electrode pole of the test battery located in the first groove through the first negative U-shaped clip; the second negative crimping sealing ring is connected to the second negative U-shaped clip through a wire, and is used to connect the negative electrode pole of the test battery located in the second groove through the second negative U-shaped clip.
[0007] As a preferred technical solution in the utility model, one side of the box cover is rotatably connected to one side of the box body through a hinge.
[0008] As a preferred technical solution in the utility model, the hinge includes a first hinge and a second hinge, and the first hinge and the second hinge are respectively arranged at two ends of one side of the box cover.
[0009] As a preferred technical solution in the present invention, the hinge is a hinge that can move 180 degrees.
[0010] As a preferred technical solution in the utility model, a liquid level observation tube made of transparent material is arranged on the side of the box body, and the two ends of the liquid level observation tube are respectively connected to the upper and lower parts of the inner side of the box body.
[0011] As a preferred technical solution in the utility model, the box body includes an aluminum alloy shell and a phenolic foam liner.
[0012] As a preferred technical solution in the present invention, the thickness of the aluminum alloy shell is 2 mm, and the thickness of the phenolic foam liner is 4 cm.
[0013] Beneficial effects: The utility model can form a liquid nitrogen freezing environment in the box, so that the electrolyte inside the battery placed in the box is inactivated due to the ultra-low temperature, and then connect the external test equipment through the positive crimping seal ring and the negative crimping seal ring, so as to accurately detect the sharp drop in battery voltage. When the voltage drops to 0V, the battery resistance can be tested by a DC resistance detection instrument to determine whether the battery has an internal short circuit. It can simply, quickly and accurately measure whether the battery has an internal short circuit, will not be limited by the influence of the test environment temperature, can be applied to batteries of different systems, does not require large equipment, and the test tooling has good portability and simple operation, thereby improving detection efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a schematic diagram of the structure of the utility model from the first viewing angle;
[0015] Figure 2 It is a structural schematic diagram of the utility model under the second viewing angle.
[0016] In the figure: 1-box body; 2-box cover; 201-liquid nitrogen flow guide port; 3-positive electrode crimping seal ring; 301-first positive electrode crimping seal ring; 302-second positive electrode crimping seal ring; 4-negative electrode crimping seal ring; 401-first negative electrode crimping seal ring; 402-second negative electrode crimping seal ring; 5-positive electrode U-shaped clip; 501-first positive electrode U-shaped clip; 502-second positive electrode U-shaped clip; 6-negative electrode U-shaped clip; 601-first negative electrode U-shaped clip; 602-second negative electrode U-shaped clip; 7-partition; 8-hinge; 801-first hinge; 802-second hinge; 9-liquid level observation tube. DETAILED DESCRIPTION
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the utility model will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the utility model, but does not constitute a limitation of the utility model.
[0018] Example:
[0019] The testing principle of the utility model is as follows: since the object to be tested is a lithium battery, which is a charged object and is equivalent to a capacitor, it also has the characteristics of a capacitor that allows AC to pass and blocks DC. Therefore, when a DC resistance meter is used directly for testing, when the voltage of the object to be tested is not 0V and the tested resistance value is tested, an open circuit state will be displayed. However, in an ultra-low temperature environment frozen by liquid nitrogen, the electrolyte is 'frozen' and the electrolyte inside the battery is inactivated, and the cell voltage will continue to drop. When the voltage continues to drop to 0V, the object to be tested no longer has the characteristics of a capacitor. At this time, the tested resistance value is equivalent to testing the electronic impedance capacity of the isolation membrane between the positive and negative electrode sheets. Therefore, when an internal short circuit occurs inside the battery, the isolation membrane loses its ability to block electrons, and the resistance value displays conduction.
[0020] like Figure 1 and Figure 2 As shown, this embodiment provides a short-circuit detection device for a lithium battery cell, comprising a box body 1 for placing a test battery and a box cover 2 sealed and buckled on the upper end of the box body 1, a positive electrode crimping sealing ring 3 connected to the positive electrode of an external test device and a negative electrode crimping sealing ring 4 connected to the negative electrode of the external test device are installed on the box cover 2, the positive electrode crimping sealing ring 3 is connected to a positive electrode U-shaped clip 5 through a wire, which is used to connect the positive electrode column of the test battery through the positive electrode U-shaped clip 5, and the negative electrode crimping sealing ring 4 is connected to a negative electrode U-shaped clip 6 through a wire, which is used to connect the negative electrode column of the test battery through the negative electrode U-shaped clip 6; the box cover 2 is provided with a liquid nitrogen guide port 201 for introducing liquid nitrogen into the box body 1.
[0021] The specific steps for detection are as follows:
[0022] Step 1: Place the battery to be tested with the pole facing upwards into the box 1;
[0023] Step 2: Connect the positive pole of the battery under test through the positive pole U-shaped clip 5 inside the positive pole crimping seal ring 3, and connect the negative pole of the battery under test through the negative pole U-shaped clip 6 inside the negative pole crimping seal ring 4;
[0024] Step 3: Connect the positive pole of the DC resistance meter through the outer wire of the positive crimping seal ring 3, connect the negative pole of the DC resistance meter through the outer wire of the negative crimping seal ring 4, connect the positive pole of the voltage detector through the outer wire of the positive crimping seal ring 3, connect the negative pole of the voltage detector through the outer wire of the negative crimping seal ring 4, and close the box cover 2 to seal;
[0025] Step 4: After completing step 3, observe that the digital displayed voltage and resistance on the DC resistance meter and voltage detector are normal, wait for 2 minutes, and record the voltage and resistance values after the digital display stabilizes and proceed to the next step;
[0026] Step 5: Introduce liquid nitrogen into the test fixture through the liquid nitrogen guide port 201. When the liquid nitrogen level reaches the required level, stop draining the liquid nitrogen and close the liquid nitrogen guide port.
[0027] Step 6: Let it stand for 20-30 minutes. When the voltage digital display on the voltage detector shows 0V, record the resistance value on the DC resistance meter at this time. The resistance value has dropped significantly compared to the initial state (MΩ→KΩ), which can be judged that there is an internal short circuit in the object being tested.
[0028] The utility model can form a liquid nitrogen freezing environment in the box body 1, so that the electrolyte inside the battery placed in the box body 1 is inactivated due to the ultra-low temperature, and then connect the external test equipment through the positive electrode crimping seal ring 3 and the negative electrode crimping seal ring 4, so as to accurately detect the sharp drop in battery voltage. When the voltage drops to 0V, the battery resistance can be tested by a DC resistance detection instrument to determine whether the battery has an internal short circuit. It can simply, quickly and accurately measure whether the battery has an internal short circuit, will not be limited by the influence of the test environment temperature, can be applicable to batteries of different systems, does not require large equipment, and the test tooling has good portability and simple operation, thereby improving the detection efficiency and accuracy.
[0029] As a preferred implementation scheme in this embodiment, it needs to be further explained that a partition 7 is provided in the box body 1, which is used to divide the internal space of the box body 1 into a first groove 101 for placing the test battery and a second groove 102 for placing the test battery through the partition 7; the positive electrode crimping seal ring 3 includes a first positive electrode crimping seal ring 301 and a second positive electrode crimping seal ring 302, the negative electrode crimping seal ring 4 includes a first negative electrode crimping seal ring 401 and a second negative electrode crimping seal ring 402, the positive electrode U-shaped clip 5 includes a first positive electrode U-shaped clip 501 and a second positive electrode U-shaped clip 502, the negative electrode U-shaped clip 6 includes a first negative electrode U-shaped clip 601 and a second negative electrode U-shaped clip 602, the first positive electrode crimping seal ring 301 is connected to the first positive electrode U-shaped clip 5 through a wire. 01 is connected to the positive pole of the test battery in the first groove 101 through the first positive U-shaped clip 501; the second positive crimping seal ring 302 is connected to the second positive U-shaped clip 502 through a wire to connect the positive pole of the test battery in the second groove 102 through the second positive U-shaped clip 502; the first negative crimping seal ring 401 is connected to the first negative U-shaped clip 601 through a wire to connect the negative pole of the test battery in the first groove 101 through the first negative U-shaped clip 601; the second negative crimping seal ring 402 is connected to the second negative U-shaped clip 602 through a wire to connect the negative pole of the test battery in the second groove 102 through the second negative U-shaped clip 602. Through the above, the test of a single or more samples can be met, thereby improving the test efficiency.
[0030] As a preferred implementation scheme in this embodiment, it needs to be further explained that one side of the box cover 2 is rotatably connected to one side of the box body 1 through a hinge 8, and the connection is simple and stable, and the operation is convenient.
[0031] As a preferred implementation scheme in this embodiment, it needs to be further explained that the hinge 8 includes a first hinge 801 and a second hinge 802, and the first hinge 801 and the second hinge 802 are respectively arranged at two ends of one side of the box cover 2, which can make the connection between the box cover 2 and the box body 1 more stable.
[0032] As a preferred implementation scheme in this embodiment, it needs to be further explained that the hinge 8 is a hinge that can move 180 degrees, with existing equipment, mature technology, low price and good stability.
[0033] As a preferred implementation scheme in this embodiment, it needs to be further explained that a liquid level observation tube 9 made of a transparent material is provided on the side of the box body 1, and the two ends of the liquid level observation tube 9 are respectively connected to the upper and lower parts of the inner side of the box body 1, so that it is convenient to observe the amount of liquid nitrogen in the box body 1 through the liquid level observation tube 9. When liquid nitrogen is introduced into the inside of the box body 1 through the liquid nitrogen guide port 201, it is convenient to observe the liquid nitrogen level through the liquid level observation port 9, and stop the liquid nitrogen drainage in time after reaching the scale line. The structure is simple and practical.
[0034] As a preferred implementation scheme in this embodiment, it needs to be further explained that the box body 1 includes an aluminum alloy shell and a phenolic foam liner, the thickness of the aluminum alloy shell is 2 mm, and the thickness of the phenolic foam liner is 4 cm, which can meet the liquid nitrogen injection amount within 2 hours to maintain the liquid volume > 60%, a DC resistance meter, and a voltage detector.
[0035] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A lithium battery cell internal short circuit detection device, characterized in that: The invention comprises a box body (1) for placing a test battery and a box cover (2) sealed and buckled on the upper end of the box body (1); a positive electrode crimping seal ring (3) connected to the positive electrode of an external test device and a negative electrode crimping seal ring (4) connected to the negative electrode of the external test device are installed on the box cover (2); the positive electrode crimping seal ring (3) is connected to a positive electrode U-shaped clamp (5) through a wire, and is used to connect to the positive electrode pole of the test battery through the positive electrode U-shaped clamp (5); the negative electrode crimping seal ring (4) is connected to a negative electrode U-shaped clamp (6) through a wire, and is used to connect to the negative electrode pole of the test battery through the negative electrode U-shaped clamp (6); and a liquid nitrogen guide port (201) for introducing liquid nitrogen into the box body (1) is arranged on the box cover (2).
2. A lithium battery cell internal short circuit detection device according to claim 1, characterized in that: The box body (1) is provided with a partition (7) for dividing the internal space of the box body (1) into a first groove (101) for placing the test battery and a second groove (102) for placing the test battery through the partition (7); the positive electrode crimping seal ring (3) comprises a first positive electrode crimping seal ring (301) and a second positive electrode crimping seal ring (302); the negative electrode crimping seal ring (4) comprises a first negative electrode crimping seal ring (401) and a second negative electrode crimping seal ring (402); the positive electrode U-shaped clip (5) comprises a first positive electrode U-shaped clip (501) and a second positive electrode U-shaped clip (502); the negative electrode U-shaped clip (6) comprises a first negative electrode U-shaped clip (601) and a second negative electrode U-shaped clip (602); the first positive electrode crimping seal ring (301) is connected to the first positive electrode U-shaped clip (501) through a wire for The positive pole of the test battery located in the first groove (101) is connected via the first positive U-shaped clip (501); the second positive crimping seal ring (302) is connected to the second positive U-shaped clip (502) via a wire, so as to connect the positive pole of the test battery located in the second groove (102) via the second positive U-shaped clip (502); the first negative crimping seal ring (401) is connected to the first negative U-shaped clip (601) via a wire, so as to connect the negative pole of the test battery located in the first groove (101) via the first negative U-shaped clip (601); the second negative crimping seal ring (402) is connected to the second negative U-shaped clip (602) via a wire, so as to connect the negative pole of the test battery located in the second groove (102) via the second negative U-shaped clip (602).
3. A lithium battery cell internal short circuit detection device according to claim 1, characterized in that: One side of the box cover (2) is rotatably connected to one side of the box body (1) via a hinge (8).
4. A lithium battery cell internal short circuit detection device according to claim 3, characterized in that: The hinge (8) comprises a first hinge (801) and a second hinge (802), and the first hinge (801) and the second hinge (802) are respectively arranged at two ends of one side of the box cover (2).
5. A lithium battery cell internal short circuit detection device according to claim 3 or 4, characterized in that: The hinge (8) is a hinge that can move through 180 degrees.
6. A lithium battery cell internal short circuit detection device according to claim 1, characterized in that: A liquid level observation tube (9) made of a transparent material is arranged on the side of the box body (1), and the two ends of the liquid level observation tube (9) are respectively connected to the upper part and the lower part of the inner side of the box body (1).
7. A lithium battery cell internal short circuit detection device according to claim 1, characterized in that: The box body (1) comprises an aluminum alloy outer shell and a phenolic foam inner shell.
8. A lithium battery cell internal short circuit detection device according to claim 7, characterized in that: The thickness of the aluminum alloy shell is 2 mm, and the thickness of the phenolic foam liner is 4 cm.