Three-electrode testing device for cylindrical battery

Abstract

The utility model provides a three-electrode testing device for a cylindrical battery, and belongs to the technical field of battery testing. The device comprises a base, a vacuum flange and a third electrode, the base is provided with a space for fixing the cathode of the cylindrical battery; a negative electrode binding post is arranged on the base; the third electrode is used for introducing a metal tube of the cylindrical battery; and the vacuum flange can be sleeved on the positive electrode of the cylindrical battery and is connected with the positive electrode lug and the third electrode through a lead. The negative electrode of the cylindrical battery is fixed through the base, the lead is preset on the vacuum flange to be connected with the third electrode and the positive electrode lug, an external clamp is not needed for fixing the lead, and the stability of electrode contact is ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and in particular to a three-electrode testing device for cylindrical batteries. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Cylindrical batteries (such as 18650 and 21700 models) currently occupy an important position in the power battery market due to their high degree of standardization, good mechanical strength, and low manufacturing cost. However, in the battery research and development process, the traditional two-electrode system (positive / negative electrode) makes it difficult to accurately monitor the electrochemical behavior of a single electrode, which limits the research on the internal reaction mechanism of the battery.

[0004] Three-electrode testing systems (working electrode, counter electrode, and reference electrode) are crucial tools in electrochemical research, enabling real-time monitoring of electrode potential, polarization behavior, and interfacial reaction kinetics, providing key data for battery material optimization and failure analysis. However, cylindrical batteries, due to their tightly sealed metal casing and confined internal space, present challenges in implementing traditional three-electrode implantation methods (such as welding the reference electrode or embedding microelectrodes), which can easily damage the original battery structure and affect testing accuracy. Currently, the construction technology for three-electrode systems in pouch and prismatic batteries is relatively mature, but dedicated testing molds for cylindrical batteries are still lacking, severely hindering in-depth electrochemical research.

[0005] The existing three-electrode testing technology for cylindrical batteries has the following problems:

[0006] 1. Using external clamps to fix the leads makes it difficult to guarantee the stability of electrode contact and the repeatability of the test.

[0007] 2. When implanting the third electrode into a cylindrical battery, holes are made in the cylindrical battery casing by mechanical drilling or laser cutting, which has problems such as electrolyte leakage, poor sealing, and complicated operation. Utility Model Content

[0008] The purpose of this invention is to provide a three-electrode testing device for cylindrical batteries to solve the technical problem of poor electrode contact stability in the three-electrode testing process of cylindrical batteries in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This utility model provides a three-electrode testing device for cylindrical batteries, comprising:

[0011] Base, vacuum flange, and third electrode;

[0012] The base has a space for fixing the negative terminal of the cylindrical battery; the base is provided with a negative electrode terminal;

[0013] The third electrode is used to introduce the metal tube into the cylindrical battery;

[0014] The vacuum flange can be fitted onto the positive electrode of the cylindrical battery and connected to the positive electrode tab and the third electrode via a lead wire.

[0015] Furthermore, the vacuum flange is provided with two lead channels, each containing one lead, namely a first lead and a second lead. The vacuum flange is provided with a positive electrode terminal and a third electrode terminal. One end of the first lead is fixedly connected to the third electrode terminal, and the other end is connected to the third electrode during use. One end of the second lead is fixedly connected to the positive electrode terminal, and the other end is connected to the positive electrode tab during use.

[0016] Furthermore, a fixing groove is provided on the top of the base, the fixing groove having space to accommodate and fix the negative terminal of the cylindrical battery.

[0017] Furthermore, the fixing groove is a cylindrical groove.

[0018] Furthermore, an insulating tube is provided inside the lead channel to isolate the lead.

[0019] Furthermore, the vacuum flange includes a hollow flange and a sealing flange, which are assembled by bolts.

[0020] Furthermore, the sealing flange is provided with a sealing groove, and a sealing ring is installed in the sealing groove.

[0021] Furthermore, the base makes electrical contact with the negative electrode tab of the cylindrical battery during use.

[0022] Furthermore, the negative electrode terminal, the positive electrode terminal, and the third electrode terminal are respectively connected to the corresponding electrode wires of the testing equipment.

[0023] Furthermore, the vacuum flange can seal the contact surface with the positive electrode shell of the cylindrical battery during use, and is sealed with epoxy resin or silicone at the lead outlet.

[0024] The technical solution of this utility model has the following beneficial effects:

[0025] 1. This utility model fixes the negative electrode of the cylindrical battery with a base and connects the third electrode and the positive electrode tab with a lead wire pre-set in the vacuum flange. It does not require external clamps to fix the lead wire, thus ensuring the stability of the electrode contact.

[0026] 2. By introducing the third electrode into the metal tube of the cylindrical battery, the repeatability of the test was achieved.

[0027] 3. The vacuum flange is fitted onto the positive terminal of the cylindrical battery to seal the contact surface between the vacuum flange and the cylindrical battery casing. At the same time, a sealing ring and a vacuum sealing gasket are installed, and epoxy resin or silicone is used to seal the lead outlet to further improve the sealing effect and prevent electrolyte leakage.

[0028] 4. This utility model has a simple structure, reliable sealing, and strong adaptability, and it is operable and convenient. It can complete the implantation of the third electrode without modifying the cylindrical battery into a pouch battery.

[0029] Advantages of the present invention in additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0031] Figure 1 This is a schematic diagram of the structure of a three-electrode testing device for a cylindrical battery according to the present invention.

[0032] The markings in the diagram are: 1. Base, 11. Fixing groove, 2. Cylindrical battery, 3. Vacuum flange, 31. Hollow flange, 32. Sealing flange, 4. Positive electrode terminal, 5. Third electrode terminal, 6. Negative electrode terminal. Detailed Implementation

[0033] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this utility model.

[0035] Where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0036] This utility model discloses a three-electrode testing device for a cylindrical battery, such as... Figure 1As shown, the device includes a base 1, a vacuum flange 3, and a third electrode. The base 1 has a space for fixing the negative electrode of the cylindrical battery 2. A negative electrode terminal 6 is provided on the base 1. The third electrode is used to introduce a metal tube into the cylindrical battery 2. The vacuum flange 3 can be fitted onto the positive electrode of the cylindrical battery 2 and is connected to the positive electrode tab and the third electrode via a lead wire. It should be noted that in this embodiment, the third electrode is a reference electrode, the positive electrode is the working electrode, and the negative electrode is the counter electrode.

[0037] In a specific embodiment, a fixing groove 11 is provided on the top of the base 1, and the fixing groove 11 has a space to accommodate and fix the negative electrode of the cylindrical battery 2.

[0038] Preferably, the fixing groove 11 is a cylindrical groove; when in use, the base 1 is in electrical contact with the negative electrode tab of the cylindrical battery 2 (the negative electrode tab of the cylindrical battery 2 is welded to the bottom of the battery casing, so the bottom of the battery casing is negatively charged), and the negative charge of the cylindrical battery 2 can be directly led out from the negative electrode terminal 6.

[0039] In a specific embodiment, the flange includes two flanges, namely a hollow flange 31 and a sealing flange 32. The hollow flange 31 has a hollow structure in the middle and can be fitted onto the cylindrical battery 2. The sealing flange 32 has a sealing surface that is in direct contact with the positive electrode of the cylindrical battery 2. The two flanges are fixed by carboxylic acid and are fitted onto the positive electrode of the cylindrical battery 2 as a whole.

[0040] The sealing flange 32 is provided with a sealing groove, bolt holes and lead wire channels.

[0041] Preferably, the sealing groove is located on the connecting surface of the flange and is used to install the sealing ring to achieve the sealing function.

[0042] Preferably, the bolt holes are evenly distributed along the edge of the flange. The two flanges are connected together by passing bolts through the bolt holes on the two opposing flanges and tightening them with nuts.

[0043] Preferably, the lead wire channel is used to pass through the lead wire, which is a metal wire bundle. The lead wire can be led out from the corresponding electrode inside the cylindrical battery 2 to the outside of the flange through the lead wire channel so as to perform electrode testing using the corresponding testing equipment. Specifically, the vacuum flange 3 is provided with two lead wire channels, each of which is provided with one lead wire, namely the first lead wire and the second lead wire. The vacuum flange 3 is provided with a positive electrode terminal 4 and a third electrode terminal 5. One end of the first lead wire is fixedly connected to the third electrode terminal 5, and the other end is connected to the third electrode when in use. One end of the second lead wire is fixedly connected to the positive electrode terminal 4, and the other end is connected to the positive electrode tab when in use.

[0044] Preferably, the lead channel has an internal insulating sleeve to isolate the lead, with each lead passing through an insulating sleeve.

[0045] The negative electrode terminal 6, the positive electrode terminal 4, and the third electrode terminal 5 are respectively connected to the corresponding electrode wires of the test equipment to realize the three-electrode test of the cylindrical battery 2.

[0046] Preferably, the vacuum flange 3 can seal the contact surface with the cylindrical battery 2 casing during use, and epoxy resin or silicone is used to seal the lead outlet to ensure a sealing effect.

[0047] In a specific implementation, the sealing ring is placed in the sealing groove of the flange. When the two flanges are fastened together by bolts, the sealing ring is compressed between the sealing surfaces of the two flanges to form a sealing barrier. At the same time, epoxy resin or silicone can be used to seal the lead outlet to prevent electrolyte leakage and ensure the sealing effect.

[0048] Furthermore, a vacuum gasket can be placed on the sealing surface of the flange, and the vacuum gasket can be compressed by tightening bolts, thereby achieving a seal in a vacuum environment.

[0049] In a specific implementation, introducing the third electrode into the cylindrical battery 2 involves: cutting open the top cover of the cylindrical battery 2 to expose a metal tube at the center of the cell electrode roll; then introducing a lithium wire or sodium wire (corresponding to the metal supporting the battery system) into the tube as the third electrode; subsequently, using a dedicated injection needle or dropper, slowly injecting electrolyte along the inner wall of the battery to avoid direct impact on the electrode plates; and finally, completing the encapsulation of the testing device. The methods for introducing the third electrode into the cylindrical battery 2 and injecting the electrolyte are existing technologies and will not be described in detail here.

[0050] Working principle of this utility model:

[0051] The third electrode is introduced into the cylindrical battery 2. Then, the negative electrode of the cylindrical battery 2 is placed in the fixing groove 11 of the base 1. The hollow flange 31 is fitted onto the positive electrode of the cylindrical battery 2. The pre-set leads of the sealing flange 32 are then connected to the positive electrode tab and the third electrode, respectively. The negative electrode terminal 6, the positive electrode terminal 4, and the third electrode terminal 5 are connected to the corresponding electrode lines of the testing equipment to begin the three-electrode test of the cylindrical battery 2.

[0052] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A three-electrode testing device for cylindrical batteries, characterized in that, Includes base, vacuum flange and third electrode; The base has a space for fixing the negative terminal of the cylindrical battery; the base is provided with a negative electrode terminal; The third electrode is used to introduce the metal tube into the cylindrical battery; The vacuum flange can be fitted onto the positive electrode of the cylindrical battery and connected to the positive electrode tab and the third electrode via a lead wire.

2. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The vacuum flange is provided with two lead channels, and each lead channel is provided with one lead, namely the first lead and the second lead. The vacuum flange is provided with a positive electrode terminal and a third electrode terminal. One end of the first lead is fixedly connected to the third electrode terminal, and the other end is connected to the third electrode when in use. One end of the second lead is fixedly connected to the positive electrode terminal, and the other end is connected to the positive electrode tab when in use.

3. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The base has a fixing groove at the top, which has space to accommodate and fix the negative terminal of the cylindrical battery.

4. The cylindrical battery three-electrode testing device as described in claim 3, characterized in that, The fixing groove is a cylindrical groove.

5. The cylindrical battery three-electrode testing device as described in claim 2, characterized in that, An insulating tube is installed inside the lead channel to isolate the lead.

6. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The vacuum flange includes a hollow flange and a sealing flange, which are assembled by bolts.

7. The cylindrical battery three-electrode testing device as described in claim 6, characterized in that, The sealing flange is provided with a sealing groove, and a sealing ring is installed in the sealing groove.

8. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The base makes electrical contact with the negative electrode tab of the cylindrical battery during use.

9. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The negative electrode terminal, positive electrode terminal, and third electrode terminal are respectively connected to the corresponding electrode wires of the test equipment.

10. The cylindrical battery three-electrode testing device as described in claim 1, characterized in that, The vacuum flange can seal the contact surface with the positive electrode shell of the cylindrical battery during use, and is sealed with epoxy resin or silicone at the lead outlet.

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