CN215451470U

CN215451470U - Reference electrode and three-stage battery using same

Info

Publication number: CN215451470U
Application number: CN202121757150.9U
Authority: CN
Inventors: 王利; 张震; 陈虎; 程世骑; 孙言飞; 闫回想; 厉运杰
Original assignee: Hefei Guoxuan High Tech Power Energy Co Ltd
Current assignee: Hefei Gotion High Tech Power Energy Co Ltd
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2022-01-07
Anticipated expiration: 2031-07-28

Abstract

The utility model discloses a reference electrode and a three-stage battery applying the same, comprising a lithium foil arranged at the lower section, a metal enameled wire arranged at the upper section and a metal foil used for connecting the lithium foil and the metal enameled wire; the lithium foil, the metal enameled wire and the metal foil are connected through ultrasonic welding, a reference electrode is arranged inside a single cell of the aluminum shell, the reference electrode is a specially-made three-section type reference electrode, the lower section of the reference electrode is a lithium metal foil and is implanted between pole pieces of the cell, the upper section of the reference electrode is a direct-welding type metal enameled wire and is led out from a battery injection hole, and the middle section of the reference electrode is a metal foil and plays a role in connecting the upper section of the reference electrode with the lower section of the lithium metal wire or the lithium metal foil.

Description

Reference electrode and three-stage battery using same

Technical Field

The utility model belongs to the field of reference electrodes, and particularly relates to a reference electrode and a three-stage battery using the same.

Background

In research works such as performance improvement and failure analysis of lithium ion batteries, a reference electrode is often introduced into the battery to form a three-electrode system. And respectively testing the potential, the impedance and the like of the anode relative to the reference electrode and the cathode relative to the reference electrode by taking the reference electrode as a reference so as to separate the potential and the impedance. The three-electrode system is one of important means in the research work of lithium ion battery mechanism.

At present, the three-electrode is widely applied to the soft package battery, but is less applied to the aluminum shell large battery. Because the aluminum shell structure of the large aluminum shell battery, the insulation film wrapped on the inner electric core and the complex structure in the battery, the implantation of the reference electrode is difficult. The existing method for preparing a three-electrode system by using an aluminum-shell large battery generally comprises the steps of forming a hole in a shell, implanting a lithium foil reference electrode, connecting a lithium foil with a metal tab, and enabling the metal tab to penetrate through the hole of the shell to form the reference electrode. In this case, the opening of the casing is large, which is easy to destroy the sealing performance and internal structure of the battery, and thus the internal system of the battery is changed, even leakage is caused. Or implanting a metal wire as a reference electrode, and then carrying out lithium plating treatment to attach a layer of lithium metal on the surface of the metal wire. However, the lithium plating layer is thin and is easily consumed in the test process, the lithium plating operation needs to be repeated, and the lithium plating procedure is time-consuming

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a reference electrode and a three-stage battery applying the same, which are used for solving the problem that the performance of the battery is influenced by the large opening of a shell when a three-electrode system of an aluminum shell large battery is manufactured at present, so that the test accuracy is not high; or the metal wire is used as a reference electrode, and the lithium plating needs to be repeated.

The purpose of the utility model can be realized by the following technical scheme:

the reference electrode comprises a lithium foil arranged at the lower section, a metal enameled wire arranged at the upper section and a metal foil used for connecting the lithium foil and the metal enameled wire;

wherein the lithium foil, the metal enameled wire and the metal foil are connected through ultrasonic welding.

Further, the diameter of the lithium foil is 5-50 μm.

Further, the thickness of the lithium foil is 5-50 μm.

Further, the metal enameled wire comprises one or more of a copper enameled wire, a nickel enameled wire, a silver enameled wire, a gold enameled wire and a platinum enameled wire.

Further, the diameter of the metal enameled wire is 20-100 μm.

Further, the metal foil includes any one of a copper foil and a nickel foil.

Further, the thickness of the metal foil is 10-100 μm.

The three-stage battery using the reference electrode comprises the reference electrode and a single battery cell provided with the reference electrode;

wherein the content of the first and second substances,

the single battery cell comprises a shell, pole pieces and a cover plate, wherein the shell and the cover plate jointly form a sealed cavity, the pole pieces are arranged in the sealed cavity, and a lithium foil is implanted between the pole pieces; a battery liquid injection hole is formed in the cover plate, and the metal enameled wire is led out from the battery liquid injection hole.

Further, the pole piece comprises a positive pole piece and a negative pole piece;

wherein a diaphragm is arranged between the positive plate and the negative plate.

Compared with the prior art, the utility model has the beneficial effects that:

through the three-section type reference electrode, a hole does not need to be formed in the battery shell, and a thin metal enameled wire at the upper section of the reference electrode is led out through the liquid injection hole, so that the damage to the battery is reduced to the maximum extent, the tightness of the battery is ensured, the original system in the battery is maintained to the maximum extent, and the test accuracy of the three-electrode battery can be greatly improved; meanwhile, the method is superior to the method which directly uses a metal wire as a reference electrode and does not need to plate lithium repeatedly.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a reference electrode according to the present invention.

Fig. 2 is a schematic view of the appearance structure of the present invention.

Fig. 3 is a schematic view of the internal structure of the present invention.

Fig. 4 is a potential diagram of three electrodes of a square aluminum-shell battery of 23Ah according to an embodiment of the present invention.

Fig. 5 is an ac impedance diagram of three electrodes of a square aluminum-shell battery of 23Ah according to an embodiment of the present invention.

In the figure: 11. a reference electrode; 111. a metal enameled wire; 112. a metal foil; 113. a lithium foil; 10. a single cell; 101. a battery injection hole; 102. a housing; 103. pole pieces; 104. and (7) a cover plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Thus, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the utility model as claimed, but is merely representative of selected embodiments of the utility model.

Traditionally, three electrodes are widely applied in soft package batteries at present, but are less applied in aluminum-shell large batteries. Because of the aluminum shell structure of the large aluminum-shell battery, the insulation film wrapped on the inner cell and the complex structure inside the battery, the implantation of the reference electrode 11 is difficult. The conventional method for preparing a three-electrode system by using an aluminum-shell large battery generally comprises the steps of forming a hole in a shell, implanting a reference electrode 11 of a lithium foil 113, connecting the lithium foil 113 with a metal tab, and enabling the metal tab to penetrate through the hole in the shell to form the reference electrode 11. In this case, the opening of the casing is large, which is easy to destroy the sealing performance and internal structure of the battery, and thus the internal system of the battery is changed, even leakage is caused. Or implanting a metal wire as a reference electrode 11, and then performing lithium plating treatment to attach a layer of lithium metal on the surface of the metal wire. However, the lithium plating layer is thin and is easily consumed in the test process, the lithium plating operation needs to be repeated, and the lithium plating procedure is time-consuming.

Based on the above description, the embodiment of the present invention provides a reference electrode 11 as shown in fig. 1, including a lithium foil 113 disposed at a lower section, a metal enameled wire 111 disposed at an upper section, and a metal foil 112 for connecting the lithium foil 113 and the metal enameled wire 111;

wherein, the lithium foil 113, the metal enameled wire 111 and the metal foil 112 are all connected by ultrasonic welding.

The used aluminum-clad battery is not required to be provided with a hole in the battery shell through the metal enameled wire 111 of the three-section type reference electrode 11, and the metal enameled wire 111 with a thinner upper section of the reference electrode 11 is led out through the liquid injection hole, so that the damage to the battery is reduced to the maximum extent, the tightness of the battery is ensured, the original system in the battery is maintained to the maximum extent, and the test accuracy of the three-electrode battery can be greatly improved; meanwhile, the method is superior to the method of directly using a metal wire as the reference electrode 11 without repeatedly plating lithium.

The scheme is explained in detail in the following with the accompanying drawings;

referring to fig. 1, as shown in fig. 1, the reference electrode 11 has a lower section of lithium foil 113, and in one embodiment, is implanted between the pole pieces 103 of the cell; the upper section is a metal enameled wire 111, which is led out from the battery filling hole 101 in one embodiment, and the middle section is a copper foil 112, which plays a role of connecting the upper section copper enameled wire and the lower section lithium metal wire or lithium foil 113.

With continued reference to fig. 1, in one embodiment, the lower lithium foil 113 of the reference electrode 11 has a diameter or thickness of 5-50 μm, and can be conveniently implanted between the positive and negative electrode sheets 103 of the battery jelly roll and separated from the positive and negative electrode sheets 103 by a separator;

in one embodiment, the upper-stage metal enameled wire 111 of the reference electrode 11 is an enameled wire made of a metal wire that does not react with internal substances such as lithium ions and electrolyte, and specifically includes: copper enameled wires, nickel enameled wires, silver enameled wires, gold enameled wires and platinum enameled wires, wherein the diameter of each enameled wire is 20-100 mu m.

In one embodiment, the metal foil 112 in the middle section of the reference electrode 11 is a metal foil 112 that does not react with internal substances such as lithium ions and electrolyte, and specifically includes: copper foil, nickel foil, etc., the thickness of the metal foil 112 is 10-100 μm;

in one embodiment, the lower lithium foil 113, the upper metal enameled wire 111 and the middle metal foil 112 of the reference electrode 11 are connected by ultrasonic welding;

besides the reference electrode 11, the application also discloses a three-stage battery using the reference electrode 11, which comprises the reference electrode 11 and a single battery cell 10 provided with the reference electrode 11; the single battery cell 10 comprises a shell 102, pole pieces 103 and a cover plate 104, wherein the shell 102 and the cover plate 104 jointly form a sealed cavity, the pole pieces 103 are arranged in the sealed cavity, and a lithium foil 113 is implanted between the pole pieces 103; the cover plate 104 is provided with a battery injection hole 101, and the metal enameled wire 111 is led out from the battery injection hole 101.

In one embodiment, the pole piece 103 comprises a positive pole piece 103 and a negative pole piece 103, wherein a separator is disposed between the positive pole piece 103 and the negative pole piece 103.

The three-electrode battery prepared in this example was subjected to charge and discharge tests, and the potentials of the full battery, the positive electrode, and the negative electrode were respectively monitored by a voltage recorder, and the test results are shown in fig. 4. The three-electrode cell was subjected to impedance tests of the full cell, the positive electrode and the negative electrode, and the test results are shown in fig. 5.

In conclusion, the thin metal enameled wire 111 on the upper section of the reference electrode 11 is led out through the liquid injection hole, so that the damage to the battery is reduced to the maximum extent, the tightness of the battery is ensured, the original system in the battery is maintained to the maximum extent, and the test accuracy of the three-electrode battery can be greatly improved; meanwhile, the method is superior to the method of directly using a metal wire as the reference electrode 11 without repeatedly plating lithium.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The specific meanings of the above terms in the present invention can be understood in specific cases by those skilled in the art; the preferred embodiments of the utility model disclosed above are intended to be illustrative only. The preferred embodiments are not exhaustive and do not limit the utility model to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, to thereby enable others skilled in the art to best utilize the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. The reference electrode is characterized by comprising a lithium foil (113) arranged at the lower section, a metal enameled wire (111) arranged at the upper section and a metal foil material (112) used for connecting the lithium foil (113) and the metal enameled wire (111);

wherein the lithium foil (113), the metal enameled wire (111) and the metal foil (112) are connected through ultrasonic welding.

2. The reference electrode according to claim 1, wherein the lithium foil (113) has a diameter of 5-50 μm.

3. The reference electrode according to claim 1, wherein the lithium foil (113) has a thickness of 5-50 μm.

4. The reference electrode according to claim 2, wherein the metal enameled wire (111) comprises one or more of a copper enameled wire, a nickel enameled wire, a silver enameled wire, a gold enameled wire and a platinum enameled wire.

5. The reference electrode according to claim 1, characterized in that the diameter of the metallic lacquered wire (111) is 20-100 μ ι η.

6. The reference electrode of claim 2, wherein the metal foil (112) comprises any one of a copper foil and a nickel foil.

7. The reference electrode of claim 4, wherein the metal foil (112) has a thickness of 10-100 μm.

8. A tertiary battery using a reference electrode, characterized by comprising the reference electrode (11) according to any one of claims 1 to 7 and a single cell (10) provided with the reference electrode (11);

wherein the content of the first and second substances,

the single battery cell (10) comprises a shell (102), pole pieces (103) and a cover plate (104), wherein the shell (102) and the cover plate (104) jointly form a sealed cavity, the pole pieces (103) are arranged in the sealed cavity, and a lithium foil (113) is implanted between the pole pieces (103); the cover plate (104) is provided with a battery liquid injection hole (101), and the metal enameled wire (111) is led out from the battery liquid injection hole (101).

9. The tertiary battery using the reference electrode according to claim 8, wherein the pole piece (103) comprises a positive pole piece (103) and a negative pole piece (103);

wherein a diaphragm is arranged between the positive plate (103) and the negative plate (103).