An apparatus and method for on-line detecting resistance using the four-probe method

Abstract

The present application provides a device and method for on-line detecting resistance using the four-probe method, belonging to the technical field of resistance testing. The device includes a support column, a slide rail and a roller group. The slide rail is rotatably sleeved outside the support column. The roller group includes a first roller and a second roller. Both the first roller and the second roller are sleeved outside the slide rail and can move on the slide rail. A first probe group is convexly provided on the outer peripheral wall of the first roller. The first probe group includes a current probe and a voltage probe which are spaced apart. A second probe group is convexly provided on the outer peripheral wall of the second roller. The second probe group includes a current probe and a voltage probe which are spaced apart. The first probe group is used to connect with a first conductive region, and the second probe group is used to connect with a second conductive region. The two current probes are electrically connected to the positive and negative electrodes of an external constant current source, and the two voltage probes are electrically connected to the positive and negative electrodes of an external voltmeter. Using this device, the transfer welding resistance can be on-line detected during the continuous production process.

Description

Technical Field

[0001] This application relates to the technical field of resistance testing. Specifically, it relates to a device and method for on-line resistance detection using the four-probe method. Background Art

[0002] Composite current collectors (usually including a polymer substrate layer and conductive layers on both sides of the polymer substrate layer) are widely used in the field of secondary battery manufacturing due to advantages such as high energy density, good safety, and low manufacturing cost. Among them, due to the polymer substrate layer in the composite current collector, it is difficult to directly weld with the tab or terminal post. Usually, it is necessary to perform a transfer weld between the composite current collector and a traditional foil, and then use the traditional foil to weld with the tab or terminal post. As the bridge for conductive connection, the resistance of the transfer weld area directly affects the performance of the corresponding battery cell. Therefore, it is particularly important to detect the resistance of the transfer weld area.

[0003] At present, most resistance detections are carried out using devices designed based on the two-probe resistance detection principle. For example, a micro-resistance quantization test device designed in CN218629622U, a thin-film solar cell insulating wire resistance on-line test device in CN 114325099A, and a resistivity measurement device for a pole piece in CN 221078789U. However, due to the small resistance of the transfer weld area (only in the milliampere level), there is a large problem of resistance detection error in two-probe resistance detection, which is not suitable for resistance detection of the transfer weld area. The four-probe resistance detection method can make up for the defects of the two-probe resistance detection method. In addition, the current process of forming a transfer weld on the composite current collector usually adopts a continuous production method, while conventional resistance detection means can only perform sampling detection (that is, the production line needs to be stopped, and then a part of the sample with a transfer weld area is intercepted for off-line resistance detection), which is difficult to monitor the overall quality of the transfer weld, thereby affecting the consistency of the prepared battery cells. Therefore, there is an urgent need to develop a device and method for on-line detection of transfer weld resistance based on the four-probe resistance detection method during the continuous production process to improve the consistency of battery cells. Summary of the Invention

[0004] The purpose of this application is to provide a device and method for on-line resistance detection using the four-probe method, which can be used to on-line detect the transfer weld resistance during the continuous production process.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a device for on-line resistance detection using a four-probe method, which is used to on-line detect the resistance of the transfer welding area of a film material. The film material includes a transfer welding area and a first conductive area and a second conductive area located on both sides of its width direction. The device includes a support column, a slide rail, and a roller group. The slide rail is rotatably sleeved outside the support column; the roller group includes two first rollers and second rollers spaced apart. Both the first rollers and the second rollers are sleeved outside the slide rail and can move on the slide rail; a first probe group is convexly provided on the outer peripheral wall of the first roller. The first probe group includes a current probe and a voltage probe spaced apart. A second probe group is convexly provided on the outer peripheral wall of the second roller. The second probe group includes a current probe and a voltage probe spaced apart; along the axial direction of the slide rail, the two voltage probes are located between the two current probes. The first probe group located on the first roller is used to connect with the first conductive area and can make the first roller and the slide rail rotate synchronously when the first conductive area moves. The second probe group located on the second roller is used to connect with the second conductive area and can make the second roller and the slide rail rotate synchronously when the second conductive area moves; the two current probes are configured to be electrically connected to the positive and negative electrodes of an external constant current source through the axial ends of the support column, and the two voltage probes are configured to be electrically connected to the positive and negative electrodes of an external voltmeter through the axial ends of the support column.

[0007] In the above technical solution, the resistance detection device has the above structure. When the position of the first roller is fixed, by continuously changing the position of the second roller on the slide rail, the linear relationship between the total resistance of the second roller plus the second conductive area between the two (i.e., the second roller and the transfer welding area) and the position of the second roller can be obtained; when the position of the second roller is fixed, by continuously changing the position of the first roller on the slide rail, the linear relationship between the total resistance of the first roller plus the first conductive area between the two (i.e., the first roller and the transfer welding area) and the position of the first roller can be obtained; then, after the positions of the first roller and the second roller are fixed, by controlling the film material to move along the length direction and driving the first roller, the second roller, and the slide rail to rotate synchronously, the resistance of the transfer welding area of the film material can be calculated according to the detected internal resistance value and the above two linear relationships.

[0008] In some alternative embodiments, along the circumferential direction of the first roller, the first probe group includes a plurality of; along the circumferential direction of the second roller, the second probe group includes a plurality of, and along the axial direction of the slide rail, the first probe group and the second probe group are arranged in one-to-one correspondence.

[0009] In the above technical solution, multiple first probe groups and second probe groups are arranged along the circumference of the corresponding roller, that is, a sufficient number of resistance detection points are set, which can more accurately reflect the transfer welding resistance of different areas of the film material in the length direction; in addition, the first probe group and the second probe group are arranged in a one-to-one correspondence along the axial direction of the slide rail, which has the advantage of a more regular overall structure.

[0010] In some optional embodiments, the first roller further includes a plurality of mounting components corresponding to the first probe groups, each mounting component includes a mounting piece, and a current probe and a voltage probe of each first probe group are mounted on the mounting piece.

[0011] In the above technical solution, multiple mounting components corresponding to the multiple first probe groups are arranged in the first roller, each mounting component includes a mounting part, and a current probe and a voltage probe of each first probe group are installed on the mounting part, which has the advantages of easy installation of the first probe group and a more reasonable layout.

[0012] In some optional embodiments, each mounting assembly further includes an elastic member, which is arranged on a side of the mounting member facing away from the first probe group along the radial direction of the first roller, so that the first probe group connected to the mounting member can reciprocate along the radial direction of the first roller under the action of the elastic member.

[0013] In the above technical solution, an elastic member is provided in the mounting assembly, and the elastic member is provided on the side of the mounting member away from the first probe group, so that the first probe group connected to the mounting member can reciprocate radially along the first roller, thereby improving the compatibility of the device with film materials of different thickness specifications. In particular, when the thicknesses of the first conductive area and the second conductive area are different, online detection of the transfer welding resistance can also be achieved through the device.

[0014] In some optional embodiments, each mounting assembly further includes a limit member, which is spaced apart from the mounting member along the radial direction of the first roller, the limit member is fixedly connected to the first roller, and the first probe group slides radially along the first roller and is penetrated into the limit member.

[0015] In the above technical solution, the installation assembly also includes a limiter, and the first probe group is slid radially along the first roller and passed through the limiter, so that the first probe group can only move radially along the first roller, thereby making the connection between the first probe group and the first conductive area more stable.

[0016] In some alternative embodiments, the interiors of the first roller and the second roller further include first current collectors extending circumferentially. The current probes of multiple first probe groups are all connected to the first current collector within the first roller, and the current probes of multiple second probe groups are all connected to the first current collector within the second roller. Moreover, both of the two first current collectors are configured to be connected to the positive and negative electrodes of an external constant current source via the axial two ends of the support column. The interiors of the first roller and the second roller further include second current collectors extending circumferentially. The voltage probes of multiple first probe groups are all connected to the second current collector within the first roller, and the voltage probes of multiple second probe groups are all connected to the second current collector within the second roller. Also, both of the two second current collectors are configured to be connected to the positive and negative electrodes of an external voltmeter via the axial two ends of the support column.

[0017] In the above technical solution, both the first roller and the second roller are provided with a first current collector and a second current collector. Among them, the multiple current probes within the first roller and the second roller are respectively connected to the corresponding first current collectors, and the multiple voltage probes within the first roller and the second roller are respectively connected to the corresponding second current collectors. By setting up the current collectors, the connections between multiple current probes and an external constant current source and between multiple voltage probes and an external voltmeter are respectively achieved, which has the advantages of relatively simple circuit layout, convenient inspection, and maintenance.

[0018] In some alternative embodiments, the inner wall of the slide rail is provided with two first current guiding rings and two second current guiding rings extending circumferentially along the slide rail. The two first current guiding rings and the two second current guiding rings are spaced apart axially along the slide rail. The two first current guiding rings are respectively conductively connected to the two first current collectors, and the two second current guiding rings are respectively conductively connected to the two second current collectors. The outer wall of the support column is provided with two third current guiding rings and two fourth current guiding rings extending circumferentially along the support column. The two third current guiding rings are respectively in one-to-one correspondence with the two first current guiding rings and are connected through conductive bearings, and the two fourth current guiding rings are respectively in one-to-one correspondence with the two second current guiding rings and are connected through conductive bearings. The two third current guiding rings are respectively connected to the positive and negative electrodes of an external voltmeter via wires through the axial two ends of the support column, and the two fourth current guiding rings are respectively connected to the positive and negative electrodes of an external voltmeter via wires through the axial two ends of the support column.

[0019] In the above technical solution, the inner wall of the slide rail is respectively provided with two first current guiding rings and two second current guiding rings corresponding to the first current collector and the second current collector one by one. At the same time, the outer wall of the support column is respectively provided with two third current guiding rings and two fourth current guiding rings corresponding to the first current guiding rings and the second current guiding rings one by one. Moreover, the first current guiding rings and the third current guiding rings, and the second current guiding rings and the fourth current guiding rings are all connected through conductive bearings, so that the slide rail can be rotatably sleeved on the support column and the internal current can be transmitted, which has the advantages of simple structure, easy manufacturing, and high structural stability.

[0020] In some alternative embodiments, along the axial direction of the slide rail, fixing blocks are provided on both sides of each roller. A plurality of fixing blocks are all connected to the outer peripheral wall of the slide rail. Each fixing block has a locked state and a disengaged state. When the fixing block is in the locked state, the fixing block is fixed to the slide rail so that the position of the roller on the slide rail is fixed; when the fixing block is in the disengaged state, the fixing block can move on the slide rail so that the roller can move on the slide rail.

[0021] In the above technical solution, fixing blocks are respectively provided on both sides of the first roller and the second roller, and the position of the roller on the slide rail can be fixed by the fixing member after the roller moves to a preset position, thereby improving the inspection accuracy of the resistance. At the same time, the stability of the roller during rotation can also be improved.

[0022] In some alternative embodiments, a limiting strip extending along the axial direction of the slide rail is convexly provided on the outer peripheral wall of the slide rail. Each fixing block is sleeved on the limiting strip and connected to the limiting strip by a bolt.

[0023] In the above technical solution, the limiting strip for installing the fixing block is convexly provided on the outer peripheral wall of the slide rail, which has the advantage of facilitating the installation of the fixing block; at the same time, the fixing block is sleeved on the limiting strip and connected to the limiting strip by a bolt, which has the advantages of simple structure and convenient operation.

[0024] In a second aspect, an embodiment of the present application provides a method for online detecting resistance using the four-probe method, which uses the device provided in the embodiment of the first aspect for detection, and includes the following steps:

[0025] Place the device above the film material so that the first probe group located on the first roller is connected to the first conductive region; and the second probe group located on the second roller is connected to the second conductive region; fix the position of the first roller on the slide rail, and adjust the distance D1 between the second roller and the transfer welding region by changing the position of the second roller on the slide rail to respectively test the DC internal resistance values R1 corresponding to different D1s. Use multiple D1s as the abscissa and the corresponding multiple DC internal resistance values R1 as the ordinate for linear fitting to obtain the slope K1; fix the position of the second roller on the slide rail, and adjust the distance D2 between the first roller and the transfer welding region by changing the position of the first roller on the slide rail to respectively test the DC internal resistance values R2 corresponding to different D2s. Use multiple D2s as the abscissa and the corresponding multiple DC internal resistance values R2 as the ordinate for linear fitting to obtain the slope K2; fix the positions of the first roller and the second roller on the slide rail at the same time to obtain the distance L1 between the first roller and the transfer welding region and the distance L2 between the second roller and the transfer welding region. Control the film material to move along the length direction to drive the first roller, the second roller and the slide rail to rotate synchronously to obtain the DC internal resistance value R3, and calculate the resistance R of the transfer welding region according to the formula 转接焊 , where the calculation formula is: R转接焊 = R3 - L1 × K2 - L2 × K1.

[0026] In the above technical solution, when operating step by step according to the above method and testing the resistance of the transfer welding area, not only the resistances of the first roller and the second roller are considered, but also the resistance of the first conductive area between the first roller and the transfer welding area and the resistance of the second conductive area between the second roller and the transfer welding area are considered. After removing them, the resistance of the transfer welding area is obtained, which can make the test result of the resistance more accurate and can reflect the transfer welding effect of the transfer welding area in real time. Description of the Drawings

[0027] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 Schematic diagram of the combination of a device for online resistance detection and a film provided by an embodiment of the present application;

[0029] Figure 2 Principle diagram of resistance detection provided by an embodiment of the present application;

[0030] Figure 3 Schematic diagram of the structure of a device for online resistance detection provided by an embodiment of the present application;

[0031] Figure 4 Schematic diagram of an internal structure of the first roller provided by an embodiment of the present application;

[0032] Figure 5 For Figure 4 Enlarged view of part A in

[0033] Figure 6 Schematic diagram of the combination of a slide rail and a support column provided by an embodiment of the present application;

[0034] Figure 7 For Figure 6 Enlarged view of part B in

[0035] Figure 8 Schematic diagram of the combination of a fixing block and a slide rail provided by an embodiment of the present application;

[0036] Figure 9 Schematic diagram of the relative position relationship between the first roller and the second roller and the film provided by the present application.

[0037] Icons: 10 - Device for online detecting resistance; 100 - Support column; 110a - Third current - guiding ring; 110b - Fourth current - guiding ring; 200 - Slide rail; 210 - Limit strip; 300 - Roller group; 310 - First roller; 320 - Second roller; 330a - First probe group; 330b - Second probe group; 331 - Current probe; 332 - Voltage probe; 340 - Mounting assembly; 341 - Mounting piece; 342 - Elastic piece; 343 - Limiting piece; 350a - First slip ring; 350b - Second slip ring; 360a - First current - guiding ring; 360b - Second current - guiding ring; 370 - Conductive bearing; 400 - Fixed block; 410 - Bolt; 20 - Membrane material; 21 - Transition welding area; 22 - First conductive area; 23 - Second conductive area; 30 - Constant - current source; 40 - Voltmeter. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0040] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0042] In the description of the present application, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0043] The following specifically describes a device and a method for online resistance detection using the four-probe method provided by the present application.

[0044] Refer to Figure 1 and Figure 2 First, in an embodiment of the present application, a device 10 for online resistance detection using the four-probe method is provided, which is used to online detect the resistance of the transfer welding area 21 of the film material 20. The film material 20 includes a transfer welding area 21 and first and second conductive areas 22 and 23 located on both sides in the width direction thereof. The device includes a support column 100, a slide rail 200, and a roller group 300. The slide rail 200 is rotatably sleeved outside the support column 100; the roller group 300 includes two first rollers 310 and second rollers 320 spaced apart. Both the first rollers 310 and the second rollers 320 are sleeved outside the slide rail 200 and can move on the slide rail 200; a first probe group 330a protrudes from the outer peripheral wall of the first roller 310. The first probe group 330a includes a current probe 331 and a voltage probe 332 spaced apart. A second probe group 330b protrudes from the outer peripheral wall of the second roller 320. The second probe group 330b includes a current probe 331 and a voltage probe 332 spaced apart; along the axial direction of the slide rail 200, the two voltage probes 332 are located between the two current probes 331. The first probe group 330a located on the first roller 310 is used to connect with the first conductive area 22 and can make the first roller 310 and the slide rail 200 rotate synchronously when the first conductive area 22 moves. The second probe group 330b located on the second roller 320 is used to connect with the second conductive area 23 and can make the second roller 320 and the slide rail 200 rotate synchronously when the second conductive area 23 moves; the two current probes 331 are configured to be electrically connected to the positive and negative electrodes of an external constant current source 30 through the axial ends of the support column 100, and the two voltage probes 332 are configured to be electrically connected to the positive and negative electrodes of an external voltmeter 40 through the axial ends of the support column 100.

[0045] In this application, the resistance detection device has the above structure. When the position of the first roller 310 is fixed, by continuously changing the position of the second roller 320 on the slide rail 200 and the corresponding internal resistance value (the internal resistance value can be obtained by R = U / I, where U can be obtained by reading the voltage of the voltmeter 40, and I is determined by the constant current source 30 and remains unchanged), the linear relationship between the total resistance of the second roller 320 plus the second conductive region 23 between the two (i.e., the second roller 320 and the transfer welding region 21) and the position of the second roller 320 can be obtained; when the position of the second roller 320 is fixed, by continuously changing the position of the first roller 310 on the slide rail 200, the linear relationship between the total resistance of the first roller 310 plus the first conductive region 22 between the two (i.e., the first roller 310 and the transfer welding region 21) and the position of the first roller 310 can be obtained; then, after the positions of the first roller 310 and the second roller 320 are fixed, the calibrated resistance of the transfer welding region 21 can be calculated by combining the measured resistance value with the above two linear relationships; then, while keeping the positions of the first roller 310 and the second roller 320 unchanged, by controlling the movement of the film material 20 in the length direction and driving the first roller 310, the second roller 320, and the slide rail 200 to rotate synchronously, the resistance of the transfer welding region 21 of the film material 20 can be calculated according to the detected internal resistance value and the above two linear relationships.

[0046] Referring to Figure 3 , as an example, along the circumferential direction of the first roller 310, the first probe group 330a includes a plurality of; along the circumferential direction of the second roller 320, the second probe group 330b includes a plurality of, and along the axial direction of the slide rail 200, the first probe group 330a and the second probe group 330b are arranged in one-to-one correspondence.

[0047] In this embodiment, the first probe group 330a and the second probe group 330b are both arranged with a plurality of along the circumferential direction of the corresponding roller, that is, a sufficient number of resistance detection points are set, which can more accurately reflect the transfer welding resistance of different regions of the film material 20 in the length direction; in addition, the first probe group 330a and the second probe group 330b are arranged in a one-to-one correspondence along the axial direction of the slide rail 200, which has the advantage of a relatively regular overall structure.

[0048] It should be noted that the specific numbers of the first probe group 330a and the second probe group 330b are not limited and can be adaptively adjusted according to actual needs.

[0049] Referring to Figure 4 and Figure 5As an example, the first roller 310 also includes a plurality of mounting components 340 corresponding to the first probe groups 330a. Each mounting component 340 includes a mounting part 341. A current probe 331 and a voltage probe 332 of each first probe group 330a are mounted on the mounting part 341.

[0050] In this embodiment, a plurality of mounting components 340 corresponding to the plurality of first probe groups 330a are provided in the first roller 310, each mounting component 340 includes a mounting part 341, and a current probe 331 and a voltage probe 332 of each first probe group 330a are mounted on the mounting part 341, which has the advantages of facilitating the installation of the first probe group 330a and having a more reasonable layout.

[0051] See also Figure 5 As an example, each mounting assembly 340 further includes an elastic member 342. Along the radial direction of the first roller 310, the elastic member 342 is arranged on the side of the mounting member 341 away from the first probe group 330a, so that the first probe group 330a connected to the mounting member 341 can reciprocate along the radial direction of the first roller 310 under the action of the elastic member 342.

[0052] In this embodiment, the mounting assembly 340 is provided with an elastic member 342, and the elastic member 342 is provided on the side of the mounting member 341 away from the first probe group 330a, so that the first probe group 330a connected to the mounting member 341 can reciprocate along the radial direction of the first roller 310, thereby improving the compatibility of the device with film materials 20 of different thickness specifications. In particular, when the thicknesses of the first conductive area 22 and the second conductive area 23 are different, online detection of the transfer welding resistance can also be achieved through the device.

[0053] See also Figure 5 As an example, each mounting assembly 340 further includes a limit member 343, which is spaced apart from the mounting member 341 along the radial direction of the first roller 310, and the limit member 343 is fixedly connected to the first roller 310, and the first probe group 330a slides along the radial direction of the first roller 310 and is penetrated into the limit member 343.

[0054] In this embodiment, the mounting assembly 340 also includes a limiter 343, and the first probe group 330a is slidably inserted into the limiter 343 along the radial direction of the first roller 310, so that the first probe group 330a can only move along the radial direction of the first roller 310, thereby making the connection between the first probe group 330a and the first conductive area 22 more stable.

[0055] It should be noted that since the overall structures and basic functions of the first roller 310 and the second roller 320 are the same, the internal structure of the second roller 320 can be set with reference to the first roller 310.

[0056] As an example, the second roller 320 further includes a plurality of mounting components 340 arranged in one-to-one correspondence with the second probe group 330b. Each mounting component 340 includes a mounting member 341, and one current probe 331 and one voltage probe 332 of each second probe group 330b are mounted on the mounting member 341.

[0057] As an example, each mounting component 340 further includes an elastic member 342. Along the radial direction of the second roller 320, the elastic member 342 is arranged on the side of the mounting member 341 facing away from the second probe group 330b, so that the second probe group 330b connected to the mounting member 341 can reciprocate along the radial direction of the second roller 320 under the action of the elastic member 342.

[0058] As an example, each mounting component 340 further includes a limiting member 343. The limiting member 343 is spaced apart from the mounting member 341 along the radial direction of the second roller 320. The limiting member 343 is fixedly connected to the second roller 320, and the second probe group 330b slides through the limiting member 343 along the radial direction of the second roller 320.

[0059] Refer to Figure 5 , as an example, the interiors of the first roller 310 and the second roller 320 further include first current collectors 350a extending circumferentially. The current probes 331 of the plurality of first probe groups 330a are all connected to the first current collector 350a in the first roller 310. The current probes 331 of the plurality of second probe groups 330b are all connected to the first current collector 350a in the second roller 320, and the two first current collectors 350a are both configured to be connected to the positive and negative electrodes of the external constant current source 30 through the axial ends of the support column 100; the interiors of the first roller 310 and the second roller 320 further include second current collectors 350b extending circumferentially. The voltage probes 332 of the plurality of first probe groups 330a are all connected to the second current collector 350b in the first roller 310. The voltage probes 332 of the plurality of second probe groups 330b are all connected to the second current collector 350b in the second roller 320, and the two second current collectors 350b are both configured to be connected to the positive and negative electrodes of the external voltmeter 40 through the axial ends of the support column 100.

[0060] In this embodiment, a first current collector ring 350a and a second current collector ring 350b are disposed inside both the first roller 310 and the second roller 320. Among them, a plurality of current probes 331 inside the first roller 310 and the second roller 320 are respectively connected to the corresponding first current collector ring 350a, and a plurality of voltage probes 332 inside the first roller 310 and the second roller 320 are respectively connected to the corresponding second current collector ring 350b. By setting the current collector rings, the connection between the plurality of current probes 331 and the external constant current source 30 and the connection between the plurality of voltage probes 332 and the external voltmeter 40 are respectively realized, which has the advantages of relatively simple circuit layout, convenient maintenance and repair, etc.

[0061] Refer to Figure 6 and Figure 7 , as an example, two first current guiding rings 360a and two second current guiding rings 360b extending along the circumferential direction of the slide rail 200 are disposed on the inner wall of the slide rail 200. The two first current guiding rings 360a and the two second current guiding rings 360b are spaced apart along the axial direction of the slide rail 200. The two first current guiding rings 360a are respectively conductively connected to the two first current collector rings 350a (optionally, they can be connected by wires or metal strips, etc.), and the two second current guiding rings 360b are respectively conductively connected to the two second current collector rings 350b (optionally, they can be connected by wires or metal strips, etc.); two third current guiding rings 110a and two fourth current guiding rings 110b extending along the circumferential direction of the support column 100 are disposed on the outer wall of the support column 100. The two third current guiding rings 110a are respectively in one-to-one correspondence with the two first current guiding rings 360a and are connected through conductive bearings 370, and the two fourth current guiding rings 110b are respectively in one-to-one correspondence with the two second current guiding rings 360b and are connected through conductive bearings 370; the two third current guiding rings 110a are respectively connected to the positive and negative electrodes of the external voltmeter 40 through wires via the two axial ends of the support column 100, and the two fourth current guiding rings 110b are respectively connected to the positive and negative electrodes of the external voltmeter 40 through wires via the two axial ends of the support column 100.

[0062] In this embodiment, two first current guiding rings 360a and two second current guiding rings 360b corresponding to the first current collector ring 350a and the second current collector ring 350b respectively are disposed on the inner wall of the slide rail 200. At the same time, two third current guiding rings 110a and two fourth current guiding rings 110b corresponding to the first current guiding ring 360a and the second current guiding ring 360b respectively are disposed on the outer wall of the support column 100. The first current guiding ring 360a and the third current guiding ring 110a, and the second current guiding ring 360b and the fourth current guiding ring 110b are all connected through conductive bearings 370, so that the slide rail 200 is rotatably sleeved on the support column 100 and can also realize the transmission of internal current, which has the advantages of simple structure, easy manufacturing and high structural stability.

[0063] It should be noted that the relative positional relationship between the two first flow guiding rings 360a and the two second flow guiding rings 360b is not limited and can be adaptively adjusted according to actual needs.

[0064] Refer to Figure 6 and Figure 7 As an example, along the axial direction of the slide rail 200, the two second flow guiding rings 360b are located between the two first flow guiding rings 360a. Correspondingly, along the axial direction of the support column 100, the two fourth flow guiding rings 110b are located between the two third flow guiding rings 110a.

[0065] Refer to Figure 8 As an example, along the axial direction of the slide rail 200, fixing blocks 400 are arranged on both sides of each roller. The plurality of fixing blocks 400 are all connected to the outer peripheral wall of the slide rail 200. Each fixing block 400 has a locked state and a disengaged state. When the fixing block 400 is in the locked state, the fixing block 400 is fixed on the slide rail 200 so that the position of the roller on the slide rail 200 is fixed; when the fixing block 400 is in the disengaged state, the fixing block 400 can move on the slide rail 200 so that the roller can move on the slide rail 200.

[0066] In this embodiment, fixing blocks 400 are respectively arranged on both sides of the first roller 310 and the second roller 320, and the position of the roller on the slide rail 200 can be fixed by fixing members after the roller moves to a preset position, thereby improving the inspection accuracy of the resistance. At the same time, the stability of the roller during rotation can also be improved.

[0067] Refer to Figure 8 As an example, a limiting strip 210 extending along the axial direction of the slide rail 200 protrudes from the outer peripheral wall of the slide rail 200. Each fixing block 400 is sleeved on the limiting strip 210 and connected to the limiting strip 210 through a bolt 410.

[0068] It should be noted that when it is necessary to fix the fixing block 400 to the slide rail 200, only the bolt 410 needs to be tightened so that the bolt 410 abuts against the outer wall of the limiting strip 210; when it is necessary to loosen the fixing block 400, only the bolt 410 needs to be rotated in the reverse direction.

[0069] In this embodiment, the limiting strip 210 for installing the fixing block 400 protrudes from the outer peripheral wall of the slide rail 200, which has the advantage of facilitating the installation of the fixing block 400; at the same time, the fixing block 400 is sleeved on the limiting strip 210 and connected to the limiting strip 210 through a bolt 410, which has the advantages of simple structure and easy operation.

[0070] It should be noted that the structures or functional components not specifically described in the resistance detection device can be set according to the conventional selection in the art.

[0071] In a second aspect, an embodiment of the present application provides a method for online detecting resistance using a four-probe method. The detection is performed using the device provided in the embodiment of the first aspect, and the method includes the following steps:

[0072] Place the device above the film material 20 so that the first probe group 330a located on the first roller 310 is connected to the first conductive region 22; and the second probe group 330b located on the second roller 320 is connected to the second conductive region 23. Fix the position of the first roller 310 on the slide rail 200, and adjust the distance D1 between the second roller 320 and the transfer welding region 21 by changing the position of the second roller 320 on the slide rail 200, so as to respectively test the DC internal resistance values R1 corresponding to different D1 values. Use multiple D1 values as the abscissa and the corresponding multiple DC internal resistance values R1 as the ordinate for linear fitting to obtain the slope K1. Fix the position of the second roller 320 on the slide rail 200, and adjust the distance D2 between the first roller 310 and the transfer welding region 21 by changing the position of the first roller 310 on the slide rail 200, so as to respectively test the DC internal resistance values R2 corresponding to different D2 values. Use multiple D2 values as the abscissa and the corresponding multiple DC internal resistance values R2 as the ordinate for linear fitting to obtain the slope K2. At the same time, fix the positions of the first roller 310 and the second roller 320 on the slide rail 200 to obtain the distance L1 between the first roller 310 and the transfer welding region 21 and the distance L2 between the second roller 320 and the transfer welding region 21. Control the film material 20 to move along the length direction to drive the first roller 310, the second roller 320, and the slide rail 200 to rotate synchronously to obtain the DC internal resistance value R3, and calculate the resistance R of the transfer welding region 21 according to the formula 转接焊 , where the calculation formula is: R 转接焊 = R3 - L1 × K2 - L2 × K1.

[0073] In the present application, when operating step by step according to the above method and testing the resistance of the transfer welding region 21, not only the resistances of the first roller 310 and the second roller 320 are considered, but also the resistance of the first conductive region 22 between the first roller 310 and the transfer welding region 21 and the resistance of the second conductive region 23 between the second roller 320 and the transfer welding region 21 are considered. After removing them, the resistance of the transfer welding region 21 is obtained, which can make the test result of the resistance more accurate and can reflect the transfer welding effect of the transfer welding region 21 in real time.

[0074] To better understand the technical solution of the present application, the relative position relationship between the first roller 310, the second roller 320 and the film material 20 is used here for auxiliary explanation. For details, please refer to Figure 9, where both D1 and L1 represent the distance from the second roller 320 to the transfer welding area 21 of the film material 20, and both D2 and L2 represent the distance from the first roller 310 to the transfer welding area 21 of the film material 20.

[0075] It should be noted that the internal resistance values R1 to R3 are all calculated based on the constant current provided by the constant current source 30 and the readings of the voltmeter 40 according to the formula R = U / I, and the internal resistance value represents the total resistance within the measurement area. Specifically: total internal resistance = (internal resistance of the first roller 310 + internal resistance of the first conductive area 22 between the first roller 310 and the transfer welding area 21) + (internal resistance of the second roller 320 + internal resistance of the second conductive area 23 between the second roller 320 and the transfer welding area 21) + internal resistance of the transfer welding area 21.

[0076] It should be noted that during the process of fixing the first roller 310 and adjusting the second roller 320, a linear relationship between the sum of the internal resistance of the second roller 320 and the internal resistance of the second conductive area 23 (the area between the second roller 320 and the transfer welding area 21) and the position of the second roller 320 can be obtained; that is, a linear relationship between the sum of the internal resistance of the second roller 320 and the internal resistance of the D1 part of the second conductive area 23 and the specific value of D1, and the slope K1 is obtained; during the process of fixing the second roller 320 and adjusting the first roller 310, a linear relationship between the sum of the internal resistance of the first roller 310 and the internal resistance of the first conductive area 22 (the area between the first roller 310 and the transfer welding area 21) and the position of the first roller 310 can be obtained; that is, a linear relationship between the sum of the internal resistance of the first roller 310 and the internal resistance of the D2 part of the first conductive area 22 and the specific value of D2, and the slope K2 is obtained. At the same time, combined with the calculation formula R 转接焊 = R3 - L1×K2 - L2×K1, when the positions of the first roller 310 and the second roller 320 are fixed, there is only R 转接焊 one variable, and R can be calculated according to this formula 转接焊 .

[0077] It should be noted that the device provided by the embodiment of the present application can not only be used to online detect the resistance of the transfer welding area on the film material, but also be used to online monitor whether the resistance of the transfer welding area of the film material is qualified, so as to improve the yield rate of the production line.

[0078] To better understand the technical solution of the present application, an example is combined here for auxiliary explanation. Taking the preparation of a composite current collector with a transfer welding area as an example, the following steps are included:

[0079] S1 Place the device above the film material 20 (composite current collector) with a qualified transfer welding area detected, so that the first probe group 330a on the first roller 310 is connected to the first conductive area 22; and the second probe group 330b on the second roller 320 is connected to the second conductive area 23. There is a qualified transfer welding area 21 between the first roller 310 and the second roller 320.

[0080] S2 Fix the position of the first roller 310 on the slide rail 200 (the distance between the first roller 310 and the qualified transfer welding area 21 is 1 cm). Adjust the position of the second roller 320 on the slide rail 200 respectively so that the distances D1 between the second roller 320 and the qualified transfer welding area 21 are 1 cm, 2 cm, and 3 cm respectively. The corresponding three internal resistance values R1 are 25.9 mΩ, 28.2 mΩ, and 29.7 mΩ in sequence. Take multiple D1 as the abscissa and the corresponding multiple DC internal resistance values R1 as the ordinate for linear fitting, and obtain the slope K1 = 1.9.

[0081] S3 Fix the position of the second roller 320 on the slide rail 200 (the distance between the second roller 320 and the qualified transfer welding area 21 is 1 cm). Adjust the position of the first roller 310 on the slide rail 200 respectively so that the distances D2 between the first roller 310 and the qualified transfer welding area 21 are 1 cm, 2 cm, and 3 cm respectively. The corresponding three internal resistance values R2 are 25.9 mΩ, 36.1 mΩ, and 45.7 mΩ in sequence. Take multiple D2 as the abscissa and the corresponding multiple DC internal resistance values R2 as the ordinate for linear fitting, and obtain the slope K2 = 9.9.

[0082] S4 Fix the positions of the first roller 310 and the second roller 320 on the slide rail 200 simultaneously, and obtain the distance L1 = 1.5 cm between the first roller 310 and the qualified transfer welding area 21, the distance L2 = 1.5 cm between the second roller 320 and the qualified transfer welding area 21, and the corresponding DC internal resistance value R3 = 31.8 mΩ. Calculate the resistance R of the qualified transfer welding area 21 according to the formula 合格转接焊 , where the calculation formula is: R 合格转接焊 = R3 - L1×K2 - L2×K1 = 14.1 mΩ.

[0083] It should be noted that steps S1 to S4 can be understood as the resistance calibration of the transfer welding area, that is, the specific value of the resistance of the transfer welding area that meets the quality requirements. And according to the quality requirements of the transfer welding, it is usually required that the difference between the measured resistance value of the transfer welding and the calibrated resistance is within ±5%, that is, the measured resistance value of the transfer welding is 14.1 mΩ×(1 ± 0.05) = (13.395 - 14.805) mΩ is acceptable.

[0084] S5 Place the device above the target film 20 (i.e., the composite current collector with a transfer welding area to be detected prepared in the production line), so that the first probe group 330a on the first roller 310 is connected to the first conductive area 22; and the second probe group 330b on the second roller 320 is connected to the second conductive area 23. At this time, the distance between the first roller 310 and the transfer welding area 21 is L3 = 1.5 cm, and the distance L4 between the second roller 320 and the transfer welding area 21 is 1.5 cm; control the film 20 to move in the length direction to drive the first roller 310, the second roller 320, and the slide rail 200 to rotate synchronously to obtain the real-time on-line DC internal resistance value R 4在线 , and the resistance formula for the on-line transfer welding area 21 is: R 在线转接焊 =R 4在线 -L3×K2 - L4×K1.

[0085] S6 Compare the resistance R 在线转接焊 of the transfer welding area of the obtained product with the resistance R 合格转接焊 range prepared in step S4. If R 在线转接焊 is within the range of (13.395~14.805) mΩ, that is, the product meets the quality requirements. If it is not within the range, the preparation process of the transfer welding needs to be adjusted.

[0086] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An apparatus for on-line detecting resistance using the four-probe method, characterized in that, The device is used for online detection of the resistance of the transfer welding area of a film material, wherein the film material includes the transfer welding area and a first conductive area and a second conductive area located on both sides of the film material in a width direction. The device includes: Support columns; A slide rail, the slide rail being rotatably sleeved on the outside of the support column; A roller group, the roller group includes two first rollers and a second roller distributed at intervals, the first roller and the second roller are both sleeved on the outside of the slide rail and can move on the slide rail; a first probe group is protruding from the outer peripheral wall of the first roller, the first probe group includes a current probe and a voltage probe distributed at intervals, and a second probe group is protruding from the outer peripheral wall of the second roller, the second probe group includes a current probe and a voltage probe distributed at intervals; along the axial direction of the slide rail, the two voltage probes are located between the two current probes, the first probe group located on the first roller is used to connect with the first conductive area, and can cause the first roller and the slide rail to rotate synchronously when the first conductive area moves, and the second probe group located on the second roller is used to connect with the second conductive area, and can cause the second roller and the slide rail to rotate synchronously when the second conductive area moves; The two current probes are configured to be electrically connected to the positive and negative poles of an external constant current source via the axial ends of the support column, and the two voltage probes are configured to be electrically connected to the positive and negative poles of an external voltmeter via the axial ends of the support column; Along the axial direction of the slide rail, fixed blocks are provided on both sides of each of the rollers, and multiple fixed blocks are connected to the outer peripheral wall of the slide rail. Each of the fixed blocks has a locking state and a disengaged state. When the fixed block is in the locking state, the fixed block is fixed on the slide rail to fix the position of the roller on the slide rail; when the fixed block is in the disengaged state, the fixed block can move on the slide rail to enable the roller to move on the slide rail.

2. The device according to claim 1, characterized in that, The first probe group includes multiple probes along the circumference of the first roller; the second probe group includes multiple probes along the circumference of the second roller, and the first probe group and the second probe group are arranged in a one-to-one correspondence along the axial direction of the slide rail.

3. The device according to claim 2, wherein The first roller also includes a plurality of mounting components arranged in one-to-one correspondence with the first probe groups, each of the mounting components includes a mounting piece, and one current probe and one voltage probe of each first probe group are mounted on the mounting piece.

4. The device according to claim 3, characterized in that, Each of the mounting components also includes an elastic member, which is arranged on the side of the mounting member away from the first probe group along the radial direction of the first roller, so that the first probe group connected to the mounting member can reciprocate along the radial direction of the first roller under the action of the elastic member.

5. The device according to claim 4, wherein, Each of the mounting components further includes a limiting member, which is spaced apart from the mounting member along the radial direction of the first roller. The limiting member is fixedly connected to the first roller, and the first probe group is slidably disposed in the limiting member along the radial direction of the first roller.

6. The device according to claim 5, characterized in that, The interiors of the first roller and the second roller further include first current collecting rings respectively extending circumferentially. The current probes of the multiple first probe groups are all connected to the first current collecting ring within the first roller, and the current probes of the multiple second probe groups are all connected to the first current collecting ring within the second roller. Moreover, the two first current collecting rings are both configured to be connected to the positive and negative electrodes of an external constant current source via the two axial ends of the support column; The interiors of the first roller and the second roller further include second current collecting rings respectively extending circumferentially. The voltage probes of the multiple first probe groups are all connected to the second current collecting ring within the first roller, and the voltage probes of the multiple second probe groups are all connected to the second current collecting ring within the second roller. Moreover, the two second current collecting rings are both configured to be connected to the positive and negative electrodes of an external voltmeter via the two axial ends of the support column.

7. The device according to claim 6, characterized in that, On the inner wall of the slide rail, there are provided two first current guiding rings and two second current guiding rings extending circumferentially along the slide rail. The two first current guiding rings and the two second current guiding rings are spaced apart axially along the slide rail. The two first current guiding rings are respectively conductively connected to the two first current collecting rings, and the two second current guiding rings are respectively conductively connected to the two second current collecting rings; On the outer wall of the support column, there are provided two third current guiding rings and two fourth current guiding rings extending circumferentially along the support column. The two third current guiding rings respectively correspond to the two first current guiding rings one by one and are connected through conductive bearings, and the two fourth current guiding rings respectively correspond to the two second current guiding rings one by one and are connected through conductive bearings; The two third current guiding rings are respectively connected to the positive and negative electrodes of an external voltmeter via wires through the two axial ends of the support column, and the two fourth current guiding rings are respectively connected to the positive and negative electrodes of an external voltmeter via wires through the two axial ends of the support column.

8. The device according to claim 1, characterized in that On the outer peripheral wall of the slide rail, there protrudes a limiting strip extending axially along the slide rail. Each fixing block is sleeved on the limiting strip and connected to the limiting strip by bolts.

9. A method for on-line detecting resistance using the four-probe method, characterized in that, Using the device according to any one of claims 1 to 8 for detection includes the following steps: Placing the device above the film material so that the first probe group located on the first roller is connected to the first conductive region; and the second probe group located on the second roller is connected to the second conductive region; Fixing the position of the first roller on the slide rail, and adjusting the distance D1 between the second roller and the transfer welding region by changing the position of the second roller on the slide rail, so as to respectively test the DC internal resistance values R1 corresponding to different D1s. Taking multiple D1s as the abscissa and the corresponding multiple DC internal resistance values R1 as the ordinate for linear fitting to obtain the slope K1; Fix the position of the second roller on the slide rail, and adjust the distance D2 between the first roller and the transfer welding area by changing the position of the first roller on the slide rail. Then, respectively test the DC internal resistance values R2 corresponding to different D2 values. Use multiple D2 values as the abscissa and the corresponding multiple DC internal resistance values R2 as the ordinate for linear fitting to obtain the slope K2; Fix the positions of the first roller and the second roller on the slide rail simultaneously to obtain the distance L1 between the first roller and the transfer welding area and the distance L2 between the second roller and the transfer welding area. Control the movement of the film material in the length direction to drive the first roller, the second roller, and the slide rail to rotate synchronously to obtain the DC internal resistance value R3, and calculate the resistance R of the transfer welding area according to the formula 转接焊 , where the calculation formula is: R 转接焊 = R3 - L1 × K2 - L2 × K1.

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