A rapid detection device and method for lithium battery defects

Abstract

This invention discloses a rapid detection device for lithium battery defects, belonging to the field of lithium battery testing. The rapid detection device includes a rotating platform; a support platform located above the rotating platform, with a lifting device between the rotating platform and the support platform for driving the support platform to rise and fall; a right-side clamping plate and a left-side clamping plate located above the support platform; a shielding cover covering the outside of the rotating platform, forming a sealed space when the shielding cover is closed; a third magnetic sensor is provided on the clamping surface of the right-side clamping plate, and a second magnetic sensor is provided on the clamping surface of the left-side clamping plate; a first magnetic sensor is connected to the inner wall of the shielding cover via a fastener, and the first magnetic sensor does not contact the right-side and left-side clamping plates when the support platform rises and falls. This invention can detect and determine the location of lithium battery defects within tens of seconds or minutes, shortening the production cycle, reducing costs, and accurately determining the location of defects in the battery.

Description

Technical Field

[0001] This invention relates to the field of lithium battery testing technology, and in particular to a rapid detection device for lithium battery defects. Background Technology

[0002] In the manufacturing process of lithium batteries, strict control is exercised over environmental dust and foreign matter at every stage of cell production to prevent dust or foreign objects from entering the battery and puncturing the separator, thus causing a micro-short circuit. However, inevitably, a small number of cells will exhibit micro-short circuit self-discharge due to the intrusion of dust or foreign objects. To screen out cells with abnormal micro-short circuit self-discharge, conventional self-discharge screening processes determine the presence of micro-short circuit self-discharge defects by detecting the voltage drop of the cell before and after a period of rest at room temperature or high temperature. This conventional defect detection method often requires a long resting time (ranging from 3 to 30 days) and a large production space to accommodate the cells during this extended period.

[0003] To address the issues of long detection cycles and large production space requirements associated with conventional lithium battery defect detection methods, this invention proposes a rapid detection device and method for lithium battery defects, which can quickly detect the presence of defects in lithium batteries within tens of seconds or minutes. Summary of the Invention

[0004] The purpose of this invention is to address the problems of long detection cycles and large production space requirements of conventional lithium battery defect detection methods, and to propose a rapid detection device for lithium battery defects.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A rapid detection device for lithium battery defects includes a rotating platform; a support platform located above the rotating platform, with a lifting device between the rotating platform and the support platform for driving the support platform to rise and fall; a right clamping plate and a left clamping plate located above the support platform, with a first pressurizing device on the support platform for driving the right clamping plate to move horizontally and a second pressurizing device on the support platform for driving the left clamping plate to move horizontally; and a shielding cover covering the outside of the rotating platform, forming a sealed space when the shielding cover is closed; wherein, a third magnetic sensor is provided on the clamping surface of the right clamping plate, a second magnetic sensor is provided on the clamping surface of the left clamping plate, and a first magnetic sensor is connected to the inner wall of the shielding cover by a fastener; in the initial state, the first magnetic sensor is located at the top of the center line of the clamping center line between the right and left clamping plates, and the first magnetic sensor does not contact the right and left clamping plates when the support platform is raised or lowered.

[0006] As a preferred embodiment of the present invention: the number of the second magnetic sensor and the third magnetic sensor is nine, which are distributed in a 3x3 grid on the right side clamp and the left side clamp. After the battery body is clamped by the right side clamp and the left side clamp, the two large S-shaped surfaces of the battery body are respectively attached to the second magnetic sensor and the third magnetic sensor.

[0007] As a preferred embodiment of the present invention, it further includes a base, the rotating platform is rotatably mounted on the base, the shielding cover is covered on the base, the base is covered to form a sealed space, the rotating platform rotates within the sealed space, and the bottom of the base is provided with a driving part for driving the rotating platform to rotate.

[0008] As a preferred embodiment of the present invention: the drive unit includes a device box installed at the bottom of the base, a motor frame is provided inside the device box, a first gear is connected to the top of the motor frame, and a second gear meshing with the first gear is connected to the bottom of the rotating platform through a rotating shaft. The rotating shaft is rotatably configured with respect to the base, and a sealing ring is provided at the connection between the rotating shaft and the base.

[0009] As a preferred embodiment of the present invention: the lifting device includes at least two first cylinders installed on the top of the rotating platform, the two ends of the supporting platform have notches, the push rod of the first cylinder passes through the notch and is fixed by bolts, the base is provided with an air circuit connector, the air circuit connector is located in the sealed space after the shielding cover is closed, and the first cylinder is sealed and connected to the air circuit connector through an air circuit pipe.

[0010] As a preferred embodiment of the present invention: the first pressurizing device and the second pressurizing device each include a support mounted on the top of the support platform, and a second cylinder is connected to each of the two supports. The output end of the second cylinder is connected to a connecting rib corresponding to the right clamping plate and the left clamping plate respectively. The second cylinder is sealed and connected to the air circuit connector through an airflow pipe.

[0011] A lithium battery defect detection method includes a rapid lithium battery defect detection device, comprising the following steps: Step 1: Data acquisition, used to acquire the magnetic field values ​​of the left and right sides of the H-back surface when the device is unloaded; and to acquire the positive and negative electrode regions of the battery by moving the device at a speed v by a height L of the lithium battery and output the magnetic field strength h_battery_back(t) data changing with time t; after loading the battery, acquiring the magnetic field values ​​of the left and right sides of the H-surface of the battery; and to acquire the positive and negative electrode regions by moving the device at a speed v by a height L of the lithium battery and output the magnetic field strength h_positive_electrode(t) and h_negative_electrode(t) data changing with time t; Step 2: Data processing, the data processing unit including a display and a data processing device electrically connected to the display, processing the data acquired by the data acquisition module and displaying the results on the display.

[0012] As a preferred embodiment of the present invention, the data processing device performs operations in the following manner: If h_large_side_face - h_back_bottom_side_face > 0, a defect is determined to exist. The area detected by the sensor corresponding to the maximum value of h_large_side_face - h_back_bottom_face ...

[0013] Compared with the prior art, the present invention provides a rapid detection device for lithium battery defects, which has the following beneficial effects: Traditional lithium battery defect detection methods rely on storing lithium batteries for 3-30 days and monitoring voltage changes before and after this period to determine the presence of defects. However, this approach prolongs production cycles, increases costs, and fails to accurately locate defects, hindering subsequent technical analysis. In contrast, this invention proposes a magnetic detection device for defective lithium batteries based on the principle of electromagnetic induction. Compared to traditional methods, this device can detect and determine the location of defects within tens of seconds or minutes, shortening production cycles, reducing costs, and accurately pinpointing the defect's location within the battery. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 3 ; Figure 4 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 4 ; Figure 5 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 5 ; Figure 6 This is a schematic diagram of the structure of a rapid detection device for lithium battery defects proposed in this invention. Figure 6 .

[0015] In the diagram: 100, rotating platform; 101, lifting device; 102, shielding cover; 103, support platform; 104, first pressurizing device; 105, right side clamping plate; 106, left side clamping plate; 107, second pressurizing device; 109, first magnetic sensor; 110, battery body; 111, second magnetic sensor; 112, fixing component; 113, third magnetic sensor; 200, base; 201, equipment box; 202, motor frame; 203, first gear; 204, second gear; 205, rotating shaft; 206, first cylinder; 207, support; 208, second cylinder; 209, air circuit connector. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "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 invention 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 invention.

[0018] Reference Figure 1-6A rapid detection device for lithium battery defects includes a rotating platform 100; a support platform 103 located above the rotating platform 100, with a lifting device 101 between the rotating platform 100 and the support platform 103 for driving the support platform 103 to rise and fall; a right clamping plate 105 and a left clamping plate 106 located above the support platform 103, with a first pressurizing device 104 on the support platform 103 for driving the right clamping plate 105 to move horizontally, and a second pressurizing device 107 on the support platform 103 for driving the left clamping plate 106 to move horizontally; and a cover for the rotating platform. The shield 102 outside the platform 100 forms a sealed space for the detection device when the shield 102 is closed. The clamping surface of the right clamping plate 105 is provided with a third magnetic sensor 113, and the clamping surface of the left clamping plate 106 is provided with a second magnetic sensor 111. The inner wall of the shield 102 is connected to a first magnetic sensor 109 by a fastener 112. In the initial state, the first magnetic sensor 109 is located at the top of the clamping center line between the right clamping plate 105 and the left clamping plate 106. When the support platform 103 is raised or lowered, the first magnetic sensor 109 does not contact the right clamping plate 105 and the left clamping plate 106.

[0019] First, the lithium battery undergoes pretreatment, charging it to a certain level of charge, bringing its State of Charge (SOC) to 1% - 100% on a rotating platform. Initially, without the battery in the testing device, the magnetic field inside the device is measured. At this point, the surrounding magnetic field may be zero or subject to other magnetic interference, obtaining a definite value. Then, the pretreated lithium battery is placed in the testing device, and the magnetic field around the battery is measured from all angles. The magnetic field value after battery loading is compared with the magnetic field value under no-load conditions to determine if the battery has defects. Therefore, this method can shorten the production cycle, reduce costs, and accurately detect defect locations, facilitating technical analysis. This device allows for the rapid detection and location of lithium battery defects, shortening the production cycle, reducing costs, and accurately determining the location of defects within the battery.

[0020] When the shield 102 is closed, the magnetic field of the device under no-load condition is detected. Then, the shield 102 is opened and the battery body 110 is placed between the right clamp 105 and the left clamp 106. Then, the first pressurizing device 104 and the second pressurizing device 107 are used to clamp the battery body 110. The lifting device 101 rises at a set speed v to the height L of the lithium battery. At the same time, the first magnetic sensor 109 starts to detect from the top (t=0) of the positive electrode area R of the battery and the bottom detection ends and outputs the data of the magnetic field strength h of the positive electrode (t) of the battery as a function of time t. The rotating platform 100 rotates 180° clockwise. The lifting device 101 descends at a set speed v to the height L of the lithium battery. At the same time, the first magnetic sensor 109 starts to detect from the bottom (t=0) of the negative electrode area R of the positive electrode area of ​​the battery and the top detection ends and outputs the data of the magnetic field strength h of the negative electrode (t) of the battery as a function of time t. The rotating platform 100 rotates 180° counterclockwise to reset.

[0021] Optionally, please refer to [link / reference]. Figures 1-6 In a preferred embodiment of the present invention: the number of the second magnetic sensor 111 and the third magnetic sensor 113 is nine, distributed in a 3x3 grid on the right clamping plate 105 and the left clamping plate 106. After the battery body 110 is clamped by the right clamping plate 105 and the left clamping plate 106, the two large S-shaped surfaces of the battery body 110 are respectively attached to the second magnetic sensor 111 and the third magnetic sensor 113.

[0022] For further details, please refer to Figures 1-6 In a preferred embodiment of the present invention, a base 200 is further included, the rotating platform 100 is rotatably disposed on the base 200, the shield 102 is covered on the base 200, and the base 200 forms a sealed space after being covered, the rotating platform 100 rotates within the sealed space, and the bottom of the base 200 is provided with a driving part for driving the rotating platform 100 to rotate.

[0023] Optionally, please refer to [link / reference]. Figures 1-6 In a preferred embodiment of the present invention: the driving unit includes a device box 201 installed at the bottom of the base 200, a motor frame 202 is provided inside the device box 201, a first gear 203 is connected to the top of the motor frame 202, and a second gear 204 that meshes with the first gear 203 is connected to the bottom of the rotating platform 100 through a rotating shaft 205. The rotating shaft 205 is rotatably disposed with the base 200, and a sealing ring is provided at the connection between the rotating shaft 205 and the base 200.

[0024] Optionally, please refer to [link / reference]. Figures 1-6In a preferred embodiment of the present invention: the lifting device 101 includes at least two first cylinders 206 mounted on the top of the rotating platform 100. The two ends of the supporting platform 103 have notches. The push rods of the first cylinders 206 pass through the notches and are fixed by bolts. The base 200 is provided with an air circuit connector 209. The air circuit connector 209 is located in the sealed space after the shield 102 is closed. The first cylinders 206 are sealed and connected to the air circuit connector 209 through air circuit pipes.

[0025] Alternatively, please refer to [link / reference]. Figures 1-6 In a preferred embodiment of the present invention: the first pressurizing device 104 and the second pressurizing device 107 respectively include a support 207 installed on the top of the support platform 103, and a second cylinder 208 is connected to each of the two supports 207. The output end of the second cylinder 208 is connected to a connecting rib plate corresponding to the right clamping plate 105 and the left clamping plate 106 respectively. The second cylinder 208 is sealed and connected to the air circuit connector 209 through an airflow pipe.

[0026] Please see Figures 1-6 A method for detecting defects in lithium batteries includes the following steps: Step 1: Data acquisition, which involves acquiring the magnetic field values ​​of the left and right sides of the H-back surface of the battery under no-load conditions; and acquiring the positive and negative electrode regions of the battery by moving the lithium battery at a speed v by a height L, and outputting data on the magnetic field strength h_battery_back(t) changing with time t. After loading the battery, acquiring the magnetic field values ​​of the left and right sides of the H-surface of the battery; and acquiring the positive and negative electrode regions by moving the lithium battery at a speed v by a height L, and outputting data on the magnetic field strength h_positive_electrode(t) and h_negative_electrode(t) changing with time t. Step 2: Data processing, wherein the data processing unit includes a display and a data processing device electrically connected to the display, which processes the data acquired by the data acquisition module and displays the results on the display.

[0027] Please see Figures 1-6 In a preferred embodiment of the present invention, the data processing device performs the following calculations: if h_large_side_left - h_back_bottom_left_left > 0, a defect is determined to exist. The area detected by the sensor corresponding to the maximum value of h_large_side_left - h_back_bottom_left is the area of ​​the corresponding defect in the lithium battery. If h_battery_positive_electrode(t) - h_battery_back_bottom(t) > 0 or h_battery_negative_electrode(t) - h_battery_back_bottom(t) > 0, a defect is determined to exist in the corresponding positive or negative electrode area. Based on the maximum value of (h_battery_positive_electrode(t) - h_positive_electrode_back_bottom(t)) or (h_battery_negative_electrode(t) - h_negative_electrode_back_bottom(t)) which corresponds to the peak magnetic field strength at the time point t, the location of the defect is determined. The battery height position of the defect on the positive electrode side is v*t peak value, and the battery height position of the defect on the negative electrode side is Lv*t peak value.

[0028] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rapid detection method for defects in lithium batteries, characterized in that: Also includes Step 1: Data acquisition, used to acquire the magnetic field values ​​on the left and right sides of the H back bottom when the acquisition device is unloaded; and to acquire the data of the positive and negative electrode regions of the battery by moving at a speed v by the height L of the lithium battery and output the data of the magnetic field strength h battery back bottom t that changes with time t. After loading the battery, the magnetic field values ​​on the left and right sides of the battery's H-plane are obtained; and the positive and negative electrode regions are obtained by moving the battery at a speed v by a height L, and the magnetic field strength h changing with time t is output. 电池正极（t） and h 电池负极（t） Data; Step 2: Data processing. The data processing unit includes a display and a data processing device electrically connected to the display. After processing the data acquired by the data acquisition module, the results are displayed on the display. The data processing device operates in the following manner: If h_large_side_area - h_back_bottom_left_area > 0, a defect is determined to exist. The area detected by the sensor corresponding to the maximum value of h_large_side_area - h_back_bottom_left_area is the area of ​​the defect in the lithium battery. 电池正极（t） -h 电池背底（t） >0 or h 电池负极（t） -h 电池背底（t） If the value is greater than 0, it indicates a defect in the corresponding positive or negative electrode region, based on h. 电池正极（t） -h 正极背底（t） Maximum value or h 电池负极（t） -h 负极背底（t） The maximum value corresponds to the peak magnetic field strength at the time point t. The location of the defect is determined by the battery height position of the defect on the positive electrode side as v*t peak value, and the battery height position of the defect on the negative electrode side as Lv*t peak value. The rapid detection method for lithium battery defects uses the following apparatus for detection, including: Rotating platform (100); A support platform (103) is located above the rotating platform (100), and a lifting device (101) is provided between the rotating platform (100) and the support platform (103) for driving the support platform (103) to rise and fall; The support platform (103) has a right clamping plate (105) and a left clamping plate (106) located above it. The support platform (103) is provided with a first pressurizing device (104) for driving the right clamping plate (105) to move horizontally, and a second pressurizing device (107) for driving the left clamping plate (106) to move horizontally. A shield (102) is placed over the outside of the rotating platform (100). After the shield (102) is closed, the detection device forms a sealed space. The clamping surface of the right clamping plate (105) is provided with a third magnetic sensor (113), the clamping surface of the left clamping plate (106) is provided with a second magnetic sensor (111), and the inner wall of the shielding cover (102) is connected to a first magnetic sensor (109) by a fastener (112). In the initial state, the first magnetic sensor (109) is located at the top of the clamping center line between the right clamping plate (105) and the left clamping plate (106). When the support platform (103) is raised or lowered, the first magnetic sensor (109) does not contact the right clamping plate (105) and the left clamping plate (106). The number of the second magnetic sensor (111) and the third magnetic sensor (113) is nine, arranged in a 3x3 grid on the right clamping plate (105) and the left clamping plate (106). After the battery body (110) is clamped by the right clamping plate (105) and the left clamping plate (106), the two large S-shaped surfaces of the battery body (110) are respectively attached to the second magnetic sensor (111) and the third magnetic sensor (113).

2. The rapid detection method for lithium battery defects according to claim 1, characterized in that: It also includes a base (200), the rotating platform (100) is rotatably mounted on the base (200), the shield (102) covers the base (200), the base (200) forms a sealed space after being covered, the rotating platform (100) rotates in the sealed space, and the bottom of the base (200) is provided with a drive unit for driving the rotating platform (100) to rotate.

3. The rapid detection method for lithium battery defects according to claim 2, characterized in that: The drive unit includes an equipment box (201) installed at the bottom of the base (200). The equipment box (201) is provided with a motor frame (202). A first gear (203) is connected to the top of the motor frame (202). The bottom of the rotating platform (100) is connected to a second gear (204) that meshes with the first gear (203) through a rotating shaft (205). The rotating shaft (205) is rotatably disposed with the base (200), and a sealing ring is provided at the connection between the rotating shaft (205) and the base (200).

4. The rapid detection method for lithium battery defects according to claim 2, characterized in that: The lifting device (101) includes at least two first cylinders (206) installed on the top of the rotating platform (100). The two ends of the support platform (103) have notches. The push rod of the first cylinder (206) passes through the notch and is fixed by bolts. The base (200) is provided with an air circuit connector (209). The air circuit connector (209) is located in the sealed space after the shield (102) is closed. The first cylinder (206) is sealed and connected to the air circuit connector (209) through an air circuit pipe.

5. The rapid detection method for lithium battery defects according to claim 4, characterized in that: The first pressurizing device (104) and the second pressurizing device (107) each include a support (207) installed on the top of the support platform (103). A second cylinder (208) is connected to each of the two supports (207). The output end of the second cylinder (208) is connected to a connecting rib plate corresponding to the right clamp plate (105) and the left clamp plate (106) respectively. The second cylinder (208) is sealed and connected to the air circuit connector (209) through an airflow pipe.

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