Device for testing internal corrosion resistance of battery cell

Abstract

The utility model discloses a device for testing the internal corrosion resistance of a battery cell, which comprises the following components arranged in sequence: a feeding station for placing the battery cell to be detected; the temperature of the constant-temperature box is adjustable, a probe I and a probe II which are connected with each other are respectively mounted on the inner top wall of the constant-temperature box in a liftable manner, the probe I can pierce the outer layer of an aluminum-plastic film of the battery cell when descending, and the probe II can be in tight lap joint with a negative tab of the battery cell when descending; heating and standing the punctured battery cell in the constant temperature box; the discharging station is used for discharging the battery cells; and the controller is in communication connection with the constant-temperature box. Therefore, the detection period is short, the detection is accurate, a corrosive liquid is not needed for testing, and the problem that the internal corrosion resistance of the battery cell is misjudged due to the fact that the corrosive liquid is polluted is avoided.

Description

Technical Field

[0001] This utility model relates to the field of soft-pack battery cell production technology, and in particular to a testing device for the internal corrosion resistance of battery cells. Background Technology

[0002] With the booming development of my country's new energy industry, consumer battery cells, energy storage battery cells, and power battery cells have been widely used. As a type of new energy battery cell, pouch cells also occupy a place in both consumer and power battery cells. Battery cell safety has always been a top priority in battery cell production, and the internal corrosion resistance of pouch cells is crucial to ensuring their long-term safe use. Poor internal corrosion resistance not only affects the normal operation of the battery cell but may also lead to leakage and gas expansion, causing serious safety accidents. Therefore, it is necessary to test the internal corrosion resistance of battery cells during production.

[0003] Currently, the existing devices in the industry for testing the internal corrosion resistance of battery cells involve immersing the cells in a room-temperature corrosive solution. This method has drawbacks such as long testing cycles and insufficient accuracy. Furthermore, the corrosive solution may be contaminated, which could lead to misjudgments of the battery cell's internal corrosion resistance. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model proposes a testing device for the internal corrosion resistance of battery cells.

[0005] This utility model proposes a testing device for the internal corrosion resistance of battery cells, comprising the following components arranged sequentially:

[0006] The loading station is used to place the battery cells to be tested;

[0007] The constant temperature chamber has an adjustable temperature and its inner top wall is equipped with probes I and II that are connected to each other. When probe I descends, it can pierce the outer layer of the aluminum-plastic film of the battery cell. When probe II descends, it can make close contact with the negative electrode tab of the battery cell. After being pierced, the battery cell is heated and left to stand in the constant temperature chamber.

[0008] The unloading station is used to discharge battery cells;

[0009] The controller is communicatively connected to the constant temperature chamber.

[0010] In this way, the testing cycle is short and the testing is accurate, and there is no need to use corrosive liquid for testing, thus avoiding the problem of misjudging the internal corrosion resistance of the battery cell due to contamination of the corrosive liquid.

[0011] Preferably, a vacuum chamber is also provided between the constant temperature chamber and the unloading station. The vacuum chamber can be set with positive and negative pressure, and can also be set with a positive-negative pressure circulation mode. After the punctured battery cell has been left to stand in the constant temperature chamber, it enters the vacuum chamber. By activating the positive-negative pressure circulation mode, the appearance of the battery cell after corrosion can be magnified.

[0012] This can amplify the undesirable appearance of the battery cell after corrosion, avoid misjudging defective battery cells, and increase the accuracy of corrosion resistance testing.

[0013] Preferably, the constant temperature chamber is equipped with a heating mechanism, which is electrically connected to the controller. The controller can set the temperature inside the constant temperature chamber between 20°C and 100°C through the heating mechanism to heat the battery cells inside the constant temperature chamber.

[0014] Preferably, the heating mechanism is an electric heating wire fixed to the inner wall of the constant temperature chamber.

[0015] This allows for rapid heating, easy control, and shorter testing time.

[0016] Preferably, cylinder I and cylinder II are installed on the inner top wall of the constant temperature chamber. Both cylinder I and cylinder II are electrically connected to the controller. The output end of cylinder I is fixed to probe I and is used to drive probe I to move up and down. The output end of cylinder II is fixed to probe II and is used to drive probe II to move up and down.

[0017] This makes it easier to control the raising and lowering of probe I and probe II to complete the corrosion resistance test.

[0018] Preferably, the vacuum chamber's opening I is connected to a blower via an air inlet pipe, and its opening II is connected to a vacuum pump via an air extraction pipe. Both the blower and the vacuum pump are communicatively connected to the controller.

[0019] Preferably, the vacuum chamber can be set with a negative pressure of -0.5 MPa to a positive pressure of 0.5 MPa.

[0020] Preferably, the positive pressure-negative pressure cycle mode is set as follows: positive pressure 0.3 MPa - negative pressure 0.3 MPa - positive pressure 0.3 MPa - negative pressure 0.3 MPa.

[0021] In this way, by cycling under positive and negative pressure, the adverse appearance of the battery cell after corrosion can be amplified, avoiding misjudgment of defective battery cells and increasing the accuracy of corrosion resistance testing.

[0022] Preferably, the loading station and the unloading station are made of rubber, plastic and acrylic sheets or other non-metallic materials.

[0023] In summary, this utility model has the following beneficial effects: The battery cells to be tested at the loading station are stored in a constant temperature chamber. Probe I punctures the aluminum layer of the aluminum-plastic film on the battery cell, and probe II tightly overlaps with the negative electrode tab. After the battery cell is damaged, it is placed in the constant temperature chamber to test its corrosion resistance. Then, the temperature inside the chamber is controlled by a controller to increase the temperature, which shortens the corrosion resistance test time and solves the problem of a long corrosion resistance test cycle. The battery cells then proceed to the unloading station, where they are manually inspected for bulges or gas. If bulges or gas are present, it indicates poor corrosion resistance. Thus, the testing cycle is short, the testing is accurate, and there is no need to use a corrosive solution for testing, avoiding the problem of misjudging the internal corrosion resistance of the battery cell due to contamination of the corrosive solution.

[0024] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] Figure 1 This is a simplified diagram of a testing device for the internal corrosion resistance of battery cells according to an embodiment of this utility model.

[0026] In the picture:

[0027] 1. Loading station; 2. Constant temperature chamber; 3. Vacuum chamber; 4. Unloading station; 5. Probe I; 6. Probe II; 7. Battery cell. Detailed Implementation

[0028] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0029] like Figure 1 As shown in the figure, the testing device for the internal corrosion resistance of a battery cell proposed in this embodiment includes the following components arranged in sequence:

[0030] Loading station 1 is used to place the battery cell 7 to be tested;

[0031] The constant temperature chamber 2 has an adjustable temperature and its inner top wall is equipped with probes I5 and II6 that are connected to each other (probe I5 is sharper than probe II6). When probe I5 descends, it can pierce the outer layer of the aluminum-plastic film of the battery cell 7. When probe II6 descends, it can tightly overlap with the negative electrode tab of the battery cell 7. After being pierced, the battery cell 7 is heated and left to stand in the constant temperature chamber 2.

[0032] It should be noted that probe I5 is interconnected with probe II6 to ensure that the negative electrode of the battery cell and the aluminum layer of the aluminum-plastic film of the battery cell are connected to form an electronic channel.

[0033] Unloading station 4 is used to discharge battery cells 7;

[0034] The controller is communicatively connected to the thermostat chamber 2.

[0035] The conveying of battery cell 7 between various workstations can be carried out using existing conveying mechanisms, such as placing the battery cell on a tray and then driving the conveying through a cylinder. The conveying mechanism is electrically connected to the controller, and the controller controls the movement of the conveying mechanism. The specific structure will not be repeated in this article, as long as it can achieve the conveying between various workstations.

[0036] In this way, the battery cell 7 to be tested on the loading station 1 is stored in the constant temperature chamber 2. Probe I5 punctures the aluminum layer of the aluminum-plastic film on the battery cell 7, and probe II6 tightly overlaps with the negative electrode tab of the battery cell 7. After the battery cell 7 is damaged, it is placed in the constant temperature chamber 2 to test its corrosion resistance. Then, the temperature inside the constant temperature chamber 2 is increased by the controller, which shortens the corrosion resistance test time and solves the problem of long corrosion resistance testing cycles. The battery cell then enters the unloading station 4, where it is manually inspected for bulges or gas. If bulges or gas are present, it indicates poor corrosion resistance. This method results in a short testing cycle, accurate testing, and eliminates the need for corrosive solutions, avoiding misjudgments of the battery cell's internal corrosion resistance due to contamination of the corrosive solution.

[0037] Furthermore, the constant temperature chamber 2 is equipped with a heating mechanism, which is electrically connected to the controller. The controller can set the temperature inside the constant temperature chamber 2 between 20℃ and 100℃ through the heating mechanism to heat up the battery cell 7 inside the constant temperature chamber 2.

[0038] Specifically, the heating mechanism is an electric heating wire fixed to the inner wall of the constant temperature chamber 2, which provides fast heating, easy control, and a simple structure. Of course, other heating mechanisms can also be used, depending on the specific circumstances.

[0039] Furthermore, cylinder I and cylinder II are installed on the inner top wall of the constant temperature chamber 2. Both cylinder I and cylinder II are electrically connected to the controller. The output end of cylinder I is fixed to probe I5 and is used to drive probe I5 to rise and fall. The output end of cylinder II is fixed to probe II6 and is used to drive probe II6 to rise and fall.

[0040] After the battery cell 7 is loaded, it is placed at the loading station 1. The controller controls the conveying mechanism to transport the battery cell 7 to the constant temperature chamber 2. After the battery cell 7 is accurately positioned in the constant temperature chamber 2, the constant temperature chamber 2 is sealed. At this time, the controller controls cylinder I to drive probe I5 to descend and pierce the aluminum-plastic film of the battery cell, making contact with the aluminum layer of the aluminum-plastic film [the aluminum-plastic film is composed of a PP layer (inner layer, the layer in contact with the electrolyte), an aluminum layer (middle layer), and a nylon layer (outer layer)]. The controller controls cylinder II to drive probe II6 to press down and overlap with the negative electrode tab of the battery cell 7, ensuring that probe II6 is in close contact with the negative electrode tab of the battery cell. The wire connects the negative electrode tab and the aluminum layer of the aluminum-plastic film of the battery cell. The negative electrode has a low potential, which at the same time lowers the potential of the aluminum layer of the aluminum-plastic film. At this time, the controller controls the heating mechanism to heat the constant temperature chamber 2 and activate the high-temperature storage mode. The temperature can be set between 30-50℃ and the time can be freely set between 3-15 days to carry out corrosion resistance testing.

[0041] If the aluminum-plastic film PP layer of cell 7 is damaged or cracked, lithium ions in the electrolyte will react with the aluminum layer under the drive of potential, causing damage to the aluminum layer and internal corrosion.

[0042] In this embodiment, a vacuum chamber 3 is also provided between the constant temperature chamber 2 and the unloading station 4. The vacuum chamber 3 can be set with positive pressure and negative pressure, and can also be set with positive pressure-negative pressure circulation mode.

[0043] Specifically, opening I of vacuum chamber 3 is connected to a blower via an air inlet pipe, and opening II is connected to a vacuum pump via an air extraction pipe. Both the blower and the vacuum pump are communicatively connected to the controller. Specifically, the positive pressure-negative pressure cycle mode is set as follows: positive pressure 0.3 MPa - negative pressure 0.3 MPa - positive pressure 0.3 MPa - negative pressure 0.3 MPa.

[0044] After the punctured battery cell 7 is placed in a constant temperature chamber 2 for a set time to complete the corrosion resistance test, the controller controls cylinders I and II to raise probes I5 and II6 respectively. Then, the controller controls the conveying mechanism to transport the battery cell 7 into the vacuum chamber 3. After the battery cell 7 is accurately positioned in the vacuum chamber 3, the vacuum chamber 3 is sealed. The controller then starts a positive pressure-negative pressure cycle mode in the vacuum chamber 3; positive pressure 0.3Mpa-negative pressure 0.3Mpa-positive pressure 0.3Mpa-negative pressure 0.3Mpa, which is used to amplify the appearance defects of the battery cell after corrosion, making it easier to observe, avoiding misjudgment of defective battery cells, and increasing the accuracy of corrosion resistance testing.

[0045] Finally, the controller controls the conveying mechanism to transport the battery cell 7 to the unloading station 4. The battery cell 7 is manually inspected for bulges or gas. If the battery cell bulges, gas, or even leaks, it indicates that the battery cell has undergone internal corrosion.

[0046] Preferably, the loading station 1 and the unloading station 4 are made of rubber, plastic and acrylic sheets or other non-metallic materials.

[0047] It should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0048] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0049] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A device for testing the internal corrosion resistance of an electric cell, characterized in that it comprises: It comprises, in sequence: An upper loading station for placing the battery to be detected; A thermostat, the temperature of which can be adjusted, the inner top wall of which is provided with a probe I and a probe II connected with each other and capable of being lifted, the probe I being capable of piercing the outer layer of the aluminum-plastic film of the battery when being lowered, and the probe II being capable of being tightly connected with the negative pole of the battery when being lowered; the battery after being pierced is heated and kept in the thermostat; A lower loading station for discharging the battery; A controller, which is communicatively connected with the thermostat.

2. The test device for the internal corrosion resistance of the battery cell according to claim 1, wherein A vacuum tank is further arranged between the thermostat and the lower loading station, the vacuum tank being capable of being provided with positive pressure and negative pressure and further capable of being provided with a positive pressure-negative pressure cycle mode; the battery after being kept in the thermostat is entered into the vacuum tank, and the appearance of the battery after being corroded can be enlarged by starting the positive pressure-negative pressure cycle mode.

3. The test device for the internal corrosion resistance of the battery cell according to claim 1, wherein A heating mechanism is arranged in the thermostat, the heating mechanism being electrically connected with the controller, the controller being capable of setting the temperature in the thermostat between 20-100 DEG C by the heating mechanism, so as to heat the battery in the thermostat.

4. The test device for the internal corrosion resistance of the battery cell according to claim 3, characterized by, The heating mechanism is an electric heating wire fixed on the inner wall of the thermostat.

5. The test device for internal corrosion resistance of battery cells according to claim 1, characterized in that, A cylinder I and a cylinder II are arranged on the inner top wall of the thermostat, the cylinder I and the cylinder II being electrically connected with the controller, the output end of the cylinder I being fixed with the probe I and used for driving the probe I to be lifted, the output end of the cylinder II being fixed with the probe II and used for driving the probe II to be lifted.

6. The test device for the internal corrosion resistance of the battery cell according to claim 2, wherein An opening I of the vacuum tank is connected with a blower through an air inlet pipe, and an opening II of the vacuum tank is connected with an air exhaust pump through an air exhaust pipe, the blower and the air exhaust pump being communicatively connected with the controller.

7. The test device for the internal corrosion resistance of the battery cell according to claim 6, wherein The vacuum tank is capable of being provided with negative pressure-0.5Mpa-positive pressure 0.5Mpa.

8. The test device for the internal corrosion resistance of the battery cell according to claim 7, characterized by, The positive pressure-negative pressure cycle mode is set as: positive pressure 0.3Mpa-negative pressure 0.3Mpa-positive pressure 0.3Mpa-negative pressure 0.3Mpa.

9. The test device for internal corrosion resistance of battery cells according to claim 1, characterized in that, The upper loading station and the lower loading station are composed of rubber, plastic and acrylic plate or other non-metallic materials.

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