Resistance detection device

Abstract

The utility model discloses a resistance detection device, and relates to the technical field of resistance detection. The resistance detection device comprises a first main probe, an ampere meter and a second main probe which are sequentially connected in series to form a first circuit; the first main probe, the first switch, the voltmeter, the second switch and the second main probe are sequentially connected in series to form a second circuit; the first branch probe group, the third switch, the voltmeter, the fourth switch and the second branch probe group are sequentially connected in series to form a third circuit. The resistance detection device provided by the utility model can detect the resistance of each layer in the multi-layer material (such as a composite current collector or a battery pole piece), so that whether the multi-layer material is qualified or not can be judged based on the resistance of each layer in the multi-layer material.

Description

Technical Field

[0001] This application relates to the technical field of resistance detection, and specifically provides a resistance detection device. Background Art

[0002] A lithium battery is an electrochemical energy storage device. Its positive electrode material is lithium metal or lithium alloy, the negative electrode material is usually graphite, and a non-aqueous electrolyte solution is used as a medium. Compared with other types of batteries, lithium batteries have the advantages of high energy density, high voltage, and low self-discharge rate, so they are widely used in various electronic devices, such as mobile phones, tablet computers, laptop computers, etc. During the production process of lithium batteries, it is necessary to manufacture composite current collectors and battery electrode sheets, both of which are components with a multi-layer structure. For example: The composite current collector is a new type of composite foil with a "metal conductive layer - PET / PP polymer material support layer - metal conductive layer" sandwich structure, using organic polymer materials such as polymer PET / PP as the support layer, and depositing metals (copper or aluminum, that is, the cathode material layer 62 or the anode material layer 63) on both the upper and lower surfaces. As Figure 1 shown, the battery electrode sheet uses the composite current collector as the support layer 61, with the cathode material layer 62 coated on the upper surface and the anode material layer 63 coated on the lower surface. In order to verify whether the composite current collector and the battery electrode sheet are qualified, it is necessary to detect the resistance of the composite current collector and the battery electrode sheet. In the prior art, only the overall resistance of the composite current collector and the battery electrode sheet can be detected during the production process, and it is impossible to detect the resistance of the cathode material layer 62 and the anode material layer 63 coated on their surfaces to verify whether the material coating is qualified. Utility Model Content

[0003] The purpose of this application is to provide a resistance detection device to solve the technical problem that in the prior art, it is impossible to detect the resistance of each layer of a multi-layer material.

[0004] To achieve the above purpose, this application provides the following technical solutions:

[0005] A resistance detection device includes:

[0006] A first main probe, an ammeter, and a second main probe that are connected in series in sequence to form a first circuit;

[0007] A first main probe, a first switch, a voltmeter, a second switch, and a second main probe that are connected in series in sequence to form a second circuit;

[0008] A first sub-probe group, a third switch, the voltmeter, a fourth switch, and a second sub-probe group that are connected in series in sequence to form a third circuit.

[0009] As a specific solution in the technical solution of the present application, the first sub-probe group and the first main probe form a probe structure; the second sub-probe group and the second main probe form a probe structure; both the first sub-probe group and the second sub-probe group have at least one sub-probe.

[0010] As a specific solution in the technical solution of the present application, the probe structure includes:

[0011] A probe fixing device;

[0012] A main probe disposed on the probe fixing device;

[0013] At least one sub-probe disposed on the probe fixing device, and the axis lines of the respective sub-probes are parallel to the axis line of the main probe.

[0014] As a specific solution in the technical solution of the present application, the respective sub-probes are evenly distributed around the axis line of the main probe.

[0015] As a specific solution in the technical solution of the present application, both the first sub-probe group and the second sub-probe group have one sub-probe; the sub-probe includes an annular probe, and the main probe is located inside the annular probe.

[0016] As a specific solution in the technical solution of the present application, both the first sub-probe group and the second sub-probe group have one sub-probe; the main probe includes an annular probe, and the sub-probe is located inside the main probe.

[0017] As a specific solution in the technical solution of the present application, the contact area formed by the first main probe and the object to be measured is a first contact area, the contact area formed by the first sub-probe group and the object to be measured is a second contact area, and the ratio of the first contact area to the second contact area is greater than or equal to 1; the contact area formed by the second main probe and the object to be measured is a third contact area, the contact area formed by the second sub-probe group and the object to be measured is a fourth contact area; the ratio of the third contact area to the fourth contact area is greater than or equal to 1.

[0018] As a specific solution in the technical solution of the present application, the end of the main probe for contacting the object to be measured is flush with the end of the sub-probe for contacting the object to be measured.

[0019] As a specific solution in the technical solution of the present application, the main probe and / or the sub-probe can be telescopically extended in a first direction, and the first direction is parallel to the axis line of the main probe.

[0020] As a specific solution in the technical solution of the present application, the first circuit further includes a power source.

[0021] Compared with the prior art, the beneficial effects of the present application are as follows:

[0022] The resistance detection device proposed in the present application can detect the resistance of each layer in a multi-layer material (such as a composite current collector or a battery electrode sheet), so as to determine whether the multi-layer material is qualified based on the resistance of each layer in the multi-layer material. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the multi-layer material proposed in the embodiment of the present application;

[0024] Figure 2 It is a schematic structural diagram of the resistance detection device proposed in the embodiment of the present application;

[0025] Figure 3 It is a schematic circuit connection diagram for testing the first resistance proposed in the embodiment of the present application;

[0026] Figure 4 It is a schematic circuit connection diagram for testing the second resistance proposed in the embodiment of the present application;

[0027] Figure 5 It is a schematic circuit connection diagram for testing the third resistance proposed in the embodiment of the present application;

[0028] Figure 6 It is a schematic diagram of a probe structure proposed in the embodiment of the present application;

[0029] Figure 7 It is a schematic diagram of another probe structure proposed in the embodiment of the present application;

[0030] Figure 8 It is a schematic diagram of another probe structure proposed in the embodiment of the present application;

[0031] Figure 9 It is a flowchart of the resistance detection method proposed in the embodiment of the present application.

[0032] In the figure: 1. Ammeter; 2. Voltmeter; 3. Probe fixing device; 4. Main probe; 41. First main probe; 42. Second main probe; 5. Sub-probe; 51. First sub-probe group; 52. Second sub-probe group; 6. Object to be measured; 61. Support body; 62. Cathode material layer; 63. Anode material layer; 64. Current-carrying area; 641. First contact surface; 642. Second contact surface; 643. Equipotential area of the cathode contact surface; 644. Equipotential area of the anode contact surface; 65. Current-free area; 7. Power supply; 81. First switch; 82. Second switch; 83. Third switch; 84. Fourth switch; 91. First circuit; 92. Second circuit; 93. Third circuit. Detailed Embodiments

[0033] 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 only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0034] It should be noted that in the description of the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. 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 understood as a limitation to the present application.

[0035] In addition, it should be understood that for the convenience of description, the sizes of the various components shown in the accompanying drawings are not drawn in actual proportional relationships. For example, the thickness or width of some layers may be exaggerated relative to other layers.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined or described in one drawing, it will not be necessary to further discuss and describe it specifically in the description of subsequent drawings.

[0037] Before understanding the technical solution of the present application, it should be clear that the basic principle of resistance testing is to energize the object to be tested 6, obtain the current passing through the object to be tested 6 and the voltage across the object to be tested 6, and obtain the resistance based on the current and voltage. In the prior art, common resistance testing devices include multimeters and resistance testers, etc. However, the above-mentioned devices can only measure the total resistance of the object to be tested 6. If the object to be tested 6 is a multi-layer material (such as the current collector or battery electrode sheet proposed in the background art), the existing devices cannot measure the resistances of the multi-layer materials separately.

[0038] As Figure 1 shown, the object to be tested proposed in the present application is as Figure 1 shown, which includes a support 61, a cathode material layer 62, and an anode material layer 63. The cathode material layer 62 covers one side of the support 61, and the anode material layer 63 covers the other side of the support 61. The first contact surface 641 is the surface where the first main probe 41 contacts the cathode material layer 62. The second contact surface 642 is the surface where the second main probe 42 contacts the anode material layer 63.

[0039] To solve the above technical problems, as Figure 2As shown in the figure, an embodiment of the present application provides a resistance detection device, which includes: a first main probe 41, a power supply 7, an ammeter 1, and a second main probe 42 that are connected in series in sequence to form a first circuit 91; a first main probe 41, a first switch 81, a voltmeter 2, a second switch 82, and a second main probe 42 that are connected in series in sequence to form a second circuit 92; a first sub-probe group 51, a third switch 83, a voltmeter 2, a fourth switch 84, and a second sub-probe group 52 that are connected in series in sequence to form a third circuit 93. Among them, the power supply 7 is mainly used to provide current, the ammeter 1 is mainly used to measure the current flowing through the object under test 6, and the voltmeter 2 is mainly used to measure voltage.

[0040] Specifically, as Figure 2 shown, if it is necessary to measure the resistance of the object under test 6, then close the first switch 81 and the second switch 82. After closing the first switch 81 and the second switch 82, the loop formed by the entire resistance detection device is as Figure 3 shown, where the data measured by the ammeter 1 is the current flowing through the object under test 6, and the data measured by the voltmeter 2 is the voltage of the object under test 6. Based on the above voltage and current, the total resistance of the object under test 6 can be obtained, and we name this resistance the first resistance.

[0041] As Figure 2 shown, if it is necessary to measure the resistance of the anode material layer 63, then close the first switch 81 and the fourth switch 84. After closing the first switch 81 and the fourth switch 84, the loop formed by the entire resistance detection device is as Figure 4 shown, where the data measured by the ammeter 1 is the current flowing through the object under test 6. It should be clear that, as Figure 1 shown, during the measurement process, since current flows through both regions where the object under test 6 contacts the two main probes 4 (i.e., the first contact surface 641 and the second contact surface 642), the current decays around to form a current region 64. In this region, there is a cathode contact surface equipotential region 643 that is equipotential with the contact surface between the support 61 and the cathode material layer 62, and an anode contact surface equipotential region 644 that is equipotential with the contact surface between the support 61 and the anode material layer 63. The current further decays to form a current-free region 65. That is to say, as Figure 4 shown, the second sub-probe group 52 contacts the anode contact surface equipotential region 644 of the object under test 6, and the data measured by the voltmeter 2 is the total voltage of the support 61 and the cathode material layer 62. Based on this voltage and current, the total resistance of the support 61 and the cathode material layer 62 is obtained, and we name this resistance the second resistance. Then, the resistance of the anode material layer 63 is the first resistance minus the second resistance. As Figure 2 shown, if it is necessary to measure the resistance of the cathode material layer 62, then close the second switch 82 and the third switch 83. After closing the second switch 82 and the third switch 83, the loop formed by the entire resistance detection device is as Figure 5As shown in the figure, the data measured by the ammeter 1 is the current flowing through the object under test 6. For similar reasons as above, the data measured by the voltmeter is the total voltage of the support 61 and the anode material layer 63. Based on this current and voltage, the total resistance of the support 61 and the anode material layer 63 can be obtained. We name this resistance the third resistance, and the resistance of the cathode material layer 62 is the first resistance minus the third resistance.

[0042] It can be seen from this that the resistance detection device proposed in this application can detect the resistance of each layer in multi-layer materials (such as composite current collectors or battery electrodes), and thus can determine whether the multi-layer materials are qualified based on the resistance of each layer in the multi-layer materials.

[0043] It should be clear that when only the resistance of the cathode material layer 62 and the anode material layer 63 needs to be detected and the resistance of the support layer 61 is ignored, the second sub-probe group 52 can also be in contact with the current-free area of the object under test 6 to detect the total resistance of the cathode material layer 62 and a part of the support layer 61. Similarly, the total resistance of the anode material 63 and a part of the support layer 61 can also be detected.

[0044] It should be clear that in the embodiments of this application, the power supply 7 can be in any form. For example, if the ammeter 1 has a power supply inside, then there is no need to configure an additional power supply 7; if the ammeter 1 does not have a power supply inside or the voltage of the power supply of the ammeter is inconsistent with the voltage required for detection, then a power supply can be configured outside the ammeter 1.

[0045] It should be clear that in the embodiments of this application, in order to ensure the accuracy during the test process, both the first sub-probe group 51 and the second sub-probe group 52 have at least one sub-probe 5. During the test process, the first main probe 41, the second main probe 42, and each sub-probe 5 can be successively pressed against the surface of the object under test 6, and then each resistance can be measured. For the convenience of using this resistance detection device, in an embodiment of this application, the first sub-probe group 51 and the first main probe 41 can form a probe structure, and the second sub-probe group 52 and the second main probe 42 can form a probe structure.

[0046] Specifically, in the embodiments of this application, the purpose of forming the probe structure by the first sub-probe group 51 and the first main probe 41, and forming the probe structure by the second sub-probe group 52 and the second main probe 42 is to facilitate the formed probe structure to form a tight contact with the surface of the object under test 6. It is easy to understand that in the embodiments of this application, the probe structure can be any structure.

[0047] Such as Figures 6 to 8As shown, in the embodiment of the present application, the probe structure includes: a probe fixing device 3; a main probe 4 (i.e., the first main probe 41 or the second main probe 42) disposed on the probe fixing device 3; at least one sub-probe 5 disposed on the probe fixing device 3, and the axis lines of the respective sub-probes 5 are parallel to the axis line of the main probe 4. It is easy to understand that the main probe 4 and the respective sub-probes 5 are concentrated together by the probe fixing device 3, and by pressing the probe fixing device 3, the main probe 4 and the respective sub-probes 5 can be brought into close contact with the surface of the object to be measured 6.

[0048] Specifically, in the embodiment of the present application, the probe fixing device 3 is mainly a carrier for fixing the main probe 4 and the respective sub-probes 5, so no restrictions are imposed on its shape and structure. For example: as Figures 6 to 8 shown, the probe fixing device 3 can be a circular block structure. Of course, in other embodiments of the present application, the probe fixing device 3 can be a square block structure or a spherical structure. It is easy to understand that the main probe 4 and the respective sub-probes 5 are made of conductive materials. To avoid electrical connection between the main probe 4 and the respective sub-probes 5, the probe fixing device 3 is made of an insulating material.

[0049] In the embodiment of the present application, the main probe 4 and the respective sub-probes 5 can be distributed on the probe fixing device 3 in any form. To ensure that both the main probe 4 and the sub-probe 5 can stably contact the surface of the object to be measured 6, as Figure 6 shown, if there are multiple sub-probes 5, the respective sub-probes 5 can be evenly distributed around the axis line of the main probe 4. As Figure 7 shown, if there are multiple sub-probes 5, the respective sub-probes 5 are connected in parallel to form a ring-shaped probe, the main probe 4 is located inside the ring-shaped probe, and the axis line of the ring-shaped probe coincides with the axis line of the main probe 4. If there is only one sub-probe 5 or multiple sub-probes 5, the respective sub-probes 5 can also be located inside the main probe 4, and the respective sub-probes 5 are evenly distributed around the axis line of the main probe 4. It should be clear that if there is only one sub-probe 5, as Figure 8 shown, the respective sub-probes 5 being evenly distributed around the axis line of the main probe 4 means that the axis line of this sub-probe 5 coincides with the axis line of the main probe 4.

[0050] It should be clear that in order to avoid a small contact area formed between the main probe 4 and the object under test 6 (which can be understood as too large resistance), while the contact area formed between the sub-probe 5 and the object under test 6 is large, the current may flow through the sub-probe 5 and affect the detection result. In an embodiment of the present application, the contact area formed by the first main probe 41 and the object under test 6 is the first contact area, and the contact area formed by the first sub-probe group 51 and the object under test 6 is the second contact area. The ratio of the first contact area to the second contact area is greater than or equal to 1. Specifically, this ratio can be any one of the values 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, or any value between two adjacent above-mentioned values. For the same reason as above, in an embodiment of the present application, the contact area formed by the second main probe 42 and the object under test 6 is the third contact area, and the contact area formed by the second sub-probe group 52 and the object under test 6 is the fourth contact area; the ratio of the third contact area to the fourth contact area is greater than or equal to 1. Specifically, this ratio can be any one of the values 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, or any value between two adjacent above-mentioned values.

[0051] It should be clear that in an embodiment of the present application, if the main probe 4 or the sub-probe 5 is in poor contact with the object under test 6, the detection result will be affected. In an embodiment of the present application, in order to improve the accuracy of the detection result, the end of the main probe 4 for contacting the object under test 6 is flush with the end of the sub-probe 5 for contacting the object under test 6. That is to say, while the main probe 4 is in contact with the surface of the object under test 6, the sub-probe 5 can also be in contact with the surface of the object under test 6.

[0052] It should be clear that in the actual production and use process, it is difficult to keep the end of the main probe 4 for contacting the object under test 6 flush with the end of the sub-probe 5 for contacting the object under test 6. In order to ensure that the main probe 4 or the sub-probe 5 can be in close contact with the object under test 6. In an embodiment of the present application, the main probe 4 and the sub-probe 5 can be designed to be telescopic along a first direction, and the first direction is parallel to the axis of the main probe 4.

[0053] Of course, in other embodiments of the present application, only the main probe 4 can be designed to be telescopic along the first direction. It should be noted that at the same time, it is necessary to ensure that the surface of the main probe 4 in contact with the object under test 6 is closer to the surface of the object under test 6 (compared with the surface of the sub-probe 5 in contact with the object under test 6); or only the sub-probe 5 is designed to be telescopic along the first direction. It should be noted that at the same time, it is necessary to ensure that the surface of the sub-probe 5 in contact with the object under test 6 is closer to the surface of the object under test 6 (compared with the surface of the main probe 4 in contact with the object under test 6).

[0054] The resistance detection device proposed in the embodiments of the present application can detect the resistance of each layer in a multi-layer material (for example: a composite current collector or a battery electrode), so as to determine whether the multi-layer material is qualified based on the resistance of each layer in the multi-layer material.

[0055] After introducing all the embodiments of the resistance detection device proposed in the present application, the embodiments of a resistance detection method proposed in the present application will be introduced below.

[0056] Specifically, as Figure 9 shown, the resistance detection method includes:

[0057] Step S100: Based on the first circuit 91 and the second circuit 92, obtain a first resistance, where the first resistance is the total resistance of the object to be measured 6.

[0058] Specifically, in the embodiments of the present application, step S100: Based on the first circuit 91 and the second circuit 92, obtain a first resistance, where the first resistance is the total resistance of the object to be measured 6 includes:

[0059] Step S110: Connect the first main probe 41 to the cathode material layer 62.

[0060] As can be seen from the foregoing, connecting the first main probe 41 to the cathode material layer 62 means closely fitting the test surface of the first main probe 41 to the test surface of the cathode material layer 62.

[0061] Step S120: Connect the second main probe 42 to the anode material layer 63.

[0062] As can be seen from the foregoing, connecting the second main probe 42 to the anode material layer 63 means closely fitting the test surface of the second main probe 42 to the test surface of the anode material layer 63.

[0063] Step S130: Close the first switch 81 and the second switch 82.

[0064] As can be seen from the foregoing, after closing the first switch 81 and the second switch 82, the closed loop formed by the resistance detection device is as Figure 3 shown, and based on the readings of the ammeter 1 and the voltmeter 2, the first resistance can be calculated.

[0065] Step S200: Based on the first circuit 91, the second circuit 92 and the third circuit 93, obtain a second resistance and a third resistance, where the second resistance is the resistance of the support 61 and the cathode material layer 62; the third resistance is the resistance of the support 61 and the anode material layer 63.

[0066] Specifically, in the embodiments of the present application, obtaining the second resistance in step S200 based on the first circuit 91, the second circuit 92 and the third circuit 93 includes:

[0067] Step S210: Connect the first main probe 41 and the first sub-probe group 51 to the cathode material layer 62.

[0068] As known from the foregoing, connecting the first sub-probe group 51 to the cathode material layer 62 means closely fitting the test surfaces of the respective sub-probes 5 of the first sub-probe group 51 to the test surface of the cathode material layer 62.

[0069] Step S220: Connect the second main probe 42 and the second sub-probe group 52 to the anode material layer 63.

[0070] As known from the foregoing, connecting the second sub-probe group 52 to the anode material layer 63 means closely fitting the test surfaces of the respective sub-probes 5 of the second sub-probe group 52 to the test surface of the anode material layer 63.

[0071] Step S230: Close the first switch 81 and the fourth switch 84.

[0072] As known from the foregoing, after closing the first switch 81 and the fourth switch 84, the closed loop formed by the resistance detection device is as Figure 4 shown. Based on the readings of the ammeter 1 and the voltmeter 2, the second resistance can be calculated.

[0073] Specifically, in the embodiment of the present application, in step S200, obtaining the third resistance based on the first circuit 91, the second circuit 92, and the third circuit 93 includes:

[0074] Step S240: Connect the first main probe 41 and the first sub-probe group 51 to the cathode material layer 62.

[0075] As known from the foregoing, connecting the first sub-probe group 51 to the cathode material layer 62 means closely fitting the test surfaces of the respective sub-probes 5 of the first sub-probe group 51 to the test surface of the cathode material layer 62.

[0076] Step S250: Connect the second main probe 42 and the second sub-probe group 52 to the anode material layer 63.

[0077] As known from the foregoing, connecting the second sub-probe group 52 to the anode material layer 63 means closely fitting the test surfaces of the respective sub-probes 5 of the second sub-probe group 52 to the test surface of the anode material layer 63.

[0078] Step S260: Close the second switch 82 and the third switch 83.

[0079] As known from the foregoing, after closing the second switch 82 and the third switch 83, the closed loop formed by the resistance detection device is as Figure 5 shown. Based on the readings of the ammeter 1 and the voltmeter 2, the third resistance can be calculated.

[0080] Step S300: Based on the first resistor, the second resistor, and the third resistor, obtain the resistances of the support 61, the cathode material layer 62, and the anode material layer 63.

[0081] As can be seen from the foregoing, the resistance of the cathode material layer 62 is equal to the first resistor minus the third resistor; the resistance of the anode material layer 63 is equal to the first resistor minus the second resistor; the resistance of the support 61 is equal to 3 times the first resistor minus the second resistor and the third resistor.

[0082] It should be clear that in the embodiments of the present application, the sequence numbers of the various steps do not represent the order of execution of the various steps. They are only used to distinguish the various steps. For example, when executing, step S100 can be executed first and then step S200, or step S200 can be executed first and then step S100. There is no restriction on this and it can be designed according to requirements.

[0083] Although the embodiments of the present application have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A resistance detection device, characterized in that: include: A first main probe (41), an ammeter (1) and a second main probe (42) are sequentially connected in series to form a first circuit (91); A first main probe (41), a first switch (81), a voltmeter (2), a second switch (82) and a second main probe (42) are sequentially connected in series to form a second circuit (92); The first sub-probe group (51), the third switch (83), the voltmeter (2), the fourth switch (84) and the second sub-probe group (52) are sequentially connected in series to form a third circuit (93).

2. The resistance detection device according to claim 1, characterized in that: The first sub-probe group (51) and the first main probe (41) form a probe structure; the second sub-probe group (52) and the second main probe (42) form a probe structure; the first sub-probe group (51) and the second sub-probe group (52) each have at least one sub-probe (5).

3. The resistance detection device according to claim 2, characterized in that: The probe structure comprises: Probe fixing device (3); A main probe (4) arranged on the probe fixing device (3); At least one sub-probe (5) is arranged on the probe fixing device (3), and the axis center line of each sub-probe (5) is parallel to the axis center line of the main probe (4).

4. The resistance detection device according to claim 3, characterized in that: The sub-probes (5) are evenly distributed around the axis of the main probe (4).

5. The resistance detection device according to claim 3, characterized in that: The first sub-probe group (51) and the second sub-probe group (52) each have a sub-probe (5); the sub-probe (5) comprises a ring-shaped probe, and the main probe (4) is located inside the ring-shaped probe.

6. The resistance detection device according to claim 3, characterized in that: The first sub-probe group (51) and the second sub-probe group (52) each have a sub-probe (5); the main probe (4) comprises a ring-shaped probe, and the sub-probe (5) is located inside the main probe (4).

7. The resistance detection device according to any one of claims 1 to 5, characterized in that: The contact area formed by the first main probe (41) and the object to be tested (6) is a first contact area, the contact area formed by the first sub-probe group (51) and the object to be tested (6) is a second contact area, and the ratio of the first contact area to the second contact area is greater than or equal to 1; The contact area formed by the second main probe (42) and the object to be tested (6) is a third contact area, and the contact area formed by the second sub-probe group (52) and the object to be tested (6) is a fourth contact area; the ratio of the third contact area to the fourth contact area is greater than or equal to 1.

8. The resistance detection device according to claim 5 or 6, characterized in that: One end of the main probe (4) used for contacting the object to be tested (6) is flush with one end of the sub-probe (5) used for contacting the object to be tested (6).

9. The resistance detection device according to claim 5 or 6, characterized in that: The main probe (4) and / or the sub-probe (5) can be extended and retracted along a first direction, and the first direction is parallel to the axis of the main probe (4).

10. The resistance detection device according to claim 9, characterized in that: The first circuit (91) also includes a power supply (7).

Images