Reference electrode and three-electrode battery

Abstract

The utility model provides a reference electrode and a three-electrode battery. The reference electrode comprises a base, a cover plate and a reference electrode column, the cover plate is detachably connected with the base, and a first via hole and a second via hole are formed in the base and the cover plate respectively; the reference electrode column is provided with a fixed part clamped between the base and the cover plate and an outward extending part which penetrates through the second via hole from one side of the cover plate and extends to the other side of the cover plate, the fixed part is used for being electrically connected with a lead in the battery cell penetrating through the first via hole, and the outward extending part is used for being connected with an external detection circuit. According to the reference electrode disclosed by the utility model, not only can the reliability of connection between the lead in the battery cell and the reference electrode column be ensured, but also the influence of abrasion of the lead in the battery cell on the test precision can be avoided, and meanwhile, the reference electrode column can be detached, so that the cyclic utilization of the reference electrode column is facilitated, and the research and development cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a reference electrode. The utility model also relates to a three-electrode battery provided with the reference electrode. Background Art

[0002] In recent years, lithium-ion batteries have become the focus of attention and achieved huge commercial value due to their outstanding performance in energy storage and conversion.

[0003] During the use of the battery, the electrolyte and the positive and negative electrode materials slowly undergo side reactions, such as changes in the battery's internal resistance, voltage reduction, and lithium deposition at the negative electrode. Therefore, in-situ monitoring of the parameters of the battery's electrochemical reaction process is crucial to understanding the operating conditions of lithium-ion batteries and determining their health. Among them, the reference electrode structure in the battery has the advantage of in-situ monitoring and characterization of the electrochemical properties of the electrode. The implanted electrodes usually have metallic lithium (Li), lithium iron phosphate (LiFePO4), or lithium titanate (Li4Ti5O12). Currently, the main method used is copper wire lithium plating, which allows the deposited lithium and the electrolyte to form a Li / Li + Electrodes are used to construct a three-electrode system, which can measure the impedance and potential of a single electrode.

[0004] At present, the preparation of square shell three-electrode lithium-ion batteries usually involves implanting a thin copper wire between the positive and negative electrodes, drilling a hole through the battery cover, and fixing it on the cover, which is then sealed with AB glue. This operation has the following disadvantages: First, the thin copper wire leading out of the cover is very likely to break during subsequent production or testing, resulting in failure of the three electrodes; second, during the preparation process, the outer insulating paint of the copper wire is easily worn and damaged, causing short circuits with the cover, affecting the test accuracy; third, even if the cover is sealed with AB glue after drilling a hole, the battery still has the risk of leakage, affecting battery performance, and even posing a safety hazard during testing. Utility Model Content

[0005] In view of this, the utility model aims to provide a reference electrode to facilitate the recycling of the reference electrode column and reduce the research and development cost.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A reference electrode comprises a base and a cover plate, and a reference electrode column;

[0008] The cover plate is detachably connected to the base, and the base and the cover plate are respectively provided with a first through hole and a second through hole;

[0009] The reference electrode column has a fixed portion clamped between the base and the cover plate, and an extended portion passing through the second via hole from one side of the cover plate and extending to the other side of the cover plate, the fixed portion is used to be electrically connected to the internal wire of the battery cell passing through the first via hole, and the extended portion is used to connect to an external detection circuit.

[0010] Furthermore, a sealing member is provided between the base and the fixing portion, and the sealing member is used to seal a gap between the base and the fixing portion.

[0011] Furthermore, the sealing member is a sealing ring; a groove for accommodating the sealing ring is provided on at least one of the base and the fixing portion, and the groove is arranged around the first via hole.

[0012] Furthermore, the cover plate includes a plate body, and an insulating layer is provided on the plate body.

[0013] Furthermore, the plate body is made of aluminum, copper, nickel, stainless steel or alloy.

[0014] Further, the base is made of aluminum, copper, nickel, stainless steel or alloy; and / or,

[0015] The reference electrode column is made of aluminum, copper, nickel, stainless steel or alloy.

[0016] Furthermore, the cover plate and the base are screwed together via a screw connection.

[0017] Furthermore, the fixing portion and the extending portion are integrally formed.

[0018] Furthermore, the cross-sections of the fixing portion and the extending portion are both circular, and the diameter of the extending portion is smaller than the diameter of the fixing portion.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] The reference electrode described in the utility model has a reference electrode column clamped between the cover plate and the base, and the cover plate and the base are detachably connected. This not only ensures the reliability of the connection between the internal wires of the battery cell and the reference electrode column, but also prevents the wear of the internal wires of the battery cell from affecting the test accuracy. At the same time, the reference electrode column can be disassembled, which is beneficial to its recycling and reduces research and development costs, thereby having a good use effect.

[0021] In addition, the sealing member provided between the base and the fixing part is conducive to ensuring the sealing between the fixing part and the base, thereby avoiding the problem of battery leakage. The sealing member adopts a sealing ring, which has a simple structure and good sealing performance. The groove provided on at least one of the base and the fixing part is conducive to ensuring the reliability of the sealing ring installation. The insulating layer provided on the cover plate is conducive to ensuring the safety of use.

[0022] In addition, the fixing part and the extension part are integrally formed, and the structure is simple and easy to process and prepare. The cross-sections of the fixing part and the extension part are both circular, and the diameter of the extension part is smaller than that of the fixing part, which is beneficial to fix the reference electrode while also helping to reduce weight and R&D costs.

[0023] Another object of the present invention is to provide a three-electrode battery, wherein the housing of the three-electrode battery is provided with the reference electrode as described above.

[0024] The three-electrode battery described in the utility model can overcome the drawbacks of the traditional three-electrode battery preparation by adopting the above-mentioned reference electrode, ensure the reliability of the connection between the reference electrode column and the internal wire of the battery cell, and facilitate the repeated recycling of the reference electrode column, thereby helping to improve the three-electrode test accuracy and battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the structure of the reference electrode described in the embodiment of the utility model;

[0027] Description of reference numerals:

[0028] 1. base; 11. first via hole; 12. groove;

[0029] 2. Cover plate; 21. Second via hole; 22. Connection hole;

[0030] 3. Reference electrode column; 31. Fixed portion; 32. Extended portion;

[0031] 4. Bolts; 5. Nuts. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0033] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" 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 a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0036] Embodiment 1

[0037] This embodiment relates to a reference electrode, which is helpful to ensure the reliability of the internal wire connection of the reference electrode column 3 and is also beneficial to the repeated recycling of the reference electrode column 3.

[0038] In terms of overall composition, Figure 1 As shown, the reference electrode of this embodiment includes a base 1 and a cover plate 2 , as well as a reference electrode column 3 .

[0039] The cover plate 2 is detachably connected to the base 1, and the base 1 and the cover plate 2 are respectively provided with a first through hole 11 and a second through hole 21. The reference electrode column 3 has a fixing portion 31 sandwiched between the base 1 and the cover plate 2, and an extending portion 32 extending from one side of the cover plate 2 through the second through hole 21 and extending to the other side of the cover plate 2. The fixing portion 31 is used to be electrically connected to the internal wire of the battery cell passing through the first through hole 11, and the extending portion 32 is used to connect to an external detection circuit.

[0040] At this time, the fixing portion 31 of the reference electrode column 3 is clamped between the cover plate 2 and the base 1, and the extending portion 32 extends from one side of the cover plate 2 through the second through hole 21 to the other side of the cover plate 2, so that the cover plate 2 and the base 1 can be detachably connected. In this way, the fixing portion 31 is convenient for electrical connection with the internal wire of the battery cell passing through the first through hole 11, thereby ensuring the reliability of the connection between the reference electrode column 3 and the internal wire of the battery cell. Moreover, the disassembly of the cover plate 2 is also conducive to the installation and disassembly of the reference electrode column 3, thereby facilitating the repeated recycling of the reference electrode column 3 and reducing the R&D cost.

[0041] Based on the above overall structure, for details, continue to refer to Figure 1As shown, in this embodiment, as a preferred implementation, in the structure of the reference electrode column 3, the fixing portion 31 and the extension portion 32 are integrally formed, the fixing portion 31 is a circular plate, the extension portion 32 is a cylindrical shape, and the diameter of the extension portion 32 is smaller than the diameter of the fixing portion 31. Such a configuration makes the reference electrode column 3 simple in structure and easy to process and prepare, and it is beneficial to the height of the reference electrode column 3, and it is also beneficial to reduce the weight and reduce the R&D cost.

[0042] In specific implementation, the reference electrode column 3 is made of a metal or alloy with good conductivity such as aluminum, copper, nickel, stainless steel, etc. Since the extension portion 32 is cylindrical, it needs to pass through the second through hole 21 on the cover plate 2 during assembly. At this time, the diameter of the extension portion 32 is less than or equal to the diameter of the second through hole 21 on the cover plate 2, so as to facilitate the smooth installation of the extension portion 32.

[0043] The base 1 and the cover plate 2 of this embodiment are both plate-shaped in structure. Preferably, the base 1 of this embodiment is made of aluminum, copper, nickel, stainless steel or alloy. The cover plate 2 of this embodiment includes a plate body, on which an insulating layer is provided. The insulating layer may be an insulating varnish coated on the plate body, or an insulating tape coated on the plate body. The provision of the insulating layer can help ensure the safety of use. Moreover, as a further preferred embodiment, the material of the plate body in this embodiment is aluminum, copper, nickel, stainless steel or alloy.

[0044] In addition, in this embodiment, a first through hole 11 is provided at the center of the base 1, and a second through hole 21 is provided at the center of the cover plate 2. In specific implementation, the fixing portion 31 of the reference electrode column 3 is located at the position of the first through hole 11, and the diameter of the first through hole 11 is slightly smaller than the diameter of the fixing portion 31, so as to facilitate the installation of the internal wire of the battery cell while preventing the fixing portion 31 from passing through the first through hole 11, thereby ensuring the fixing effect of the fixing portion 31 between the base 1 and the cover plate 2.

[0045] In this embodiment, preferably, the length of the cover plate 2 is between 3-5 cm, the width is between 1-3 cm, the height is between 0.2-0.5 cm, and the diameter of the second via hole 21 is between 0.5-2 cm. The length and width of the base 1 are generally consistent with the cover plate 2. The first via hole 11 is arranged at the center of the base 1, and the diameter of the first via hole 11 is between 0.8-1.8 cm. In the reference electrode column 3, the diameter of the extension portion 32 is smaller than the diameter of the second via hole 21, and the height of the extension portion 32 is between 1-2 cm. The diameter of the fixing portion 31 is between 1-2 cm, and the height of the fixing portion 31 is between 0.2-0.5 cm. The diameter of the first via hole 11 is 1.8 cm.

[0046] In a specific implementation, the length of the cover plate 2 is 5 cm, the width is 3 cm, the height is 0.4 cm, and the diameter of the second through hole 21 is 2 cm. The length, width and height of the base 1 are consistent with those of the cover plate 2, and the diameter of the first through hole 11 is 1.8 cm. The diameter of the extension portion 32 of the reference electrode column 3 is, for example, 1.5 cm, the height of the extension portion 32 is 2 cm, the diameter of the fixing portion 31 is 2 cm, and the height of the fixing portion 31 is 0.3 cm.

[0047] In this embodiment, a first connecting hole 22 and a second connecting hole 22 are respectively provided on the base 1 and the cover plate 2. By sequentially passing through the bolts 4 in the first connecting hole 22 and the second connecting hole 22, and screwing in cooperation with the bolts 4, the cover plate 2 is screwed to the base 1, thereby realizing a detachable connection between the cover plate 2 and the base 1.

[0048] It is worth noting that bolts 4 or studs can be fixed on one of the base 1 or the cover plate 2, and the base 1 and the cover plate 2 can be screwed together by passing the studs through the connection holes 22 set on the other of the base 1 or the cover plate 2 and the nuts 5 matched with the studs. Of course, it can be understood that in addition to the base 1 and the cover plate 2 being connected by screw connection, the two can also be connected by snap connection or plug connection to achieve a detachable connection between the two. In addition, it is also worth noting that the materials of the bolts 4 or studs and the nuts 5 in this embodiment are also preferably aluminum, stainless steel or alloy.

[0049] In order to ensure the sealing between the base 1 and the reference electrode column 3, in this embodiment, still refer to Figure 1 As shown, a sealing member is provided between the base 1 and the fixing portion 31, and the sealing member is used to seal the gap between the base 1 and the fixing portion 31. As a preferred embodiment, in this embodiment, the sealing member is a sealing ring, and a groove 12 for accommodating the sealing ring is provided on the base 1, and the groove 12 is arranged around the first via 11. At this time, the sealing ring installed in the groove 12 can ensure the sealing of the connection between the fixing portion 31 and the base 1, and the battery leakage problem can be effectively avoided during use.

[0050] In specific implementation, the sealing ring is made of rubber material. The inner diameter of the groove 12 is between 0.9-1.9 cm, slightly larger than the diameter of the first via hole 11, and the outer diameter of the groove 12 is between 1.1-2.1 cm.

[0051] It should be noted that, in addition to being provided on the base 1, the groove 12 may also be provided only at the bottom of the fixing portion 31, or a first half groove and a second half groove may be provided at the bottom of the fixing portion 31 and the base 1 respectively, and the first half groove and the second half groove are both arranged around the first through hole 11, and when the bottom is fitted and connected to the base 1, the first half groove and the second half groove may be buckled together to form a groove 12 for accommodating a sealing ring.

[0052] The reference electrode of this embodiment can not only ensure the reliability of the connection between the internal wires of the battery cell and the reference electrode column 3, but also avoid the wear of the internal wires of the battery cell affecting the test accuracy through the detachable connection between the cover plate 2 and the base 1, and also make the reference electrode column 3 detachable, which is beneficial to its recycling, reduces the R&D cost, and has a good use effect.

[0053] Embodiment 2

[0054] This embodiment relates to a three-electrode battery, the housing of which is provided with the reference electrode described in the first embodiment.

[0055] Specifically, the base 1 of the reference electrode can be welded to the side wall of the shell of the three-electrode battery, or welded to the bottom of the shell of the three-electrode battery. Corresponding to the position of the reference electrode, an opening is provided on the shell of the three-electrode battery, and the opening can facilitate the lead-out of the internal wires of the battery cell. Moreover, the lead-out internal wires of the battery cell pass through the first via 11 and are welded to the fixing part 31, so that the internal wires of the battery cell are electrically connected to the fixing part 31.

[0056] In a specific implementation, in a three-electrode battery, the internal wire of the cell is usually a copper wire, which is implanted between the positive and negative electrodes of the electrode group to separate the diaphragm and prevent the copper wire from directly contacting the positive and negative electrodes. An opening is set on the three-electrode shell, and the base 1 is laser welded at the opening position of the three-electrode shell. After the electrode group is put into the shell, the copper wire is led out through the first through hole 11 on the base 1 and welded to the fixing part 31 of the reference electrode column 3 by soldering. Then the sealing ring is installed in the groove 12, the extension part 32 of the reference electrode column 3 passes through the second through hole 21, and the reference electrode column 3 is fixed between the cover plate 2 and the base 1 by bolts 4 and nuts 5.

[0057] The three-electrode battery of this embodiment, by adopting the above-mentioned reference electrode, can overcome the drawbacks of the traditional three-electrode battery preparation, ensure the reliability of the connection between the reference electrode column 3 and the internal wire of the battery cell, and facilitate the repeated recycling of the reference electrode column 3, thereby helping to improve the three-electrode test accuracy and battery performance.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A reference electrode, characterized in that: Includes base and cover, and reference electrode column; The cover plate is detachably connected to the base, and the base and the cover plate are respectively provided with a first through hole and a second through hole; The reference electrode column has a fixed portion clamped between the base and the cover plate, and an extended portion passing through the second via hole from one side of the cover plate and extending to the other side of the cover plate, the fixed portion is used to be electrically connected to the internal wire of the battery cell passing through the first via hole, and the extended portion is used to connect to an external detection circuit.

2. The reference electrode according to claim 1, characterized in that: A sealing member is provided between the base and the fixing portion, and the sealing member is used to seal a gap between the base and the fixing portion.

3. The reference electrode according to claim 2, characterized in that: The sealing member is a sealing ring; A groove for accommodating the sealing ring is provided on at least one of the base and the fixing portion, and the groove is arranged around the first through hole.

4. The reference electrode according to claim 1, characterized in that: The cover plate comprises a plate body, and an insulating layer is arranged on the plate body.

5. The reference electrode according to claim 4, characterized in that: The material of the plate body is aluminum, copper, nickel, stainless steel or alloy.

6. The reference electrode according to claim 1, characterized in that: The base is made of aluminum, copper, nickel, stainless steel or alloy; and / or, The reference electrode column is made of aluminum, copper, nickel, stainless steel or alloy.

7. The reference electrode according to claim 1, characterized in that: The cover plate is screwed to the base via a screw connection.

8. The reference electrode according to any one of claims 1 to 7, characterized in that: The fixing portion and the extending portion are integrally formed.

9. The reference electrode according to claim 8, characterized in that: The cross sections of the fixing portion and the extending portion are both circular, and the diameter of the extending portion is smaller than the diameter of the fixing portion.

10. A three-electrode battery, characterized in that: The housing of the three-electrode battery is provided with a reference electrode as claimed in any one of claims 1 to 9.

Images