Three-electrode device of lithium ion battery

Abstract

The utility model discloses a three-electrode device of a lithium ion battery. The three-electrode device comprises a pole piece, a lower bottom cover and an upper top cover, a groove is formed in the lower bottom cover according to the size of the pole piece and is used for placing the pole piece; a positive electrode lug, a negative electrode lug and a reference electrode lug are arranged on the lower bottom cover and are in one-to-one correspondence with the positive electrode, the negative electrode and the reference electrode of the pole piece; a convex groove is formed in the upper top cover according to the size of the pole piece and is used for fixing the pole piece; according to the device, a cell does not need to be pre-valued into a reference electrode, the influence of potential change of the reference electrode does not exist, the tested three-electrode data is high in reliability and accuracy, and the device has good universality.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium - ion batteries, in particular to a three - electrode device for lithium - ion batteries. Background Art

[0002] With the rise of the new energy industry, lithium - ion batteries, as a green, efficient, and high - specific - energy energy storage device, have received increasing attention from all sectors of society. With the rapid development of lithium - ion batteries, batteries of different forms and models such as square, cylindrical, and soft - pack have emerged in the lithium - battery industry, and the technology update speed of batteries has been continuously improving; and studying the positive and negative electrode plates, which are essential components of lithium - ion batteries, has become an inevitable technical approach. However, based on the two - electrode system, the charge - discharge behavior of the entire lithium - ion battery is tested, and the positive and negative electrodes of the lithium - ion battery cannot be distinguished; therefore, an auxiliary reference electrode needs to be set up to form a three - electrode system battery; the three - electrode battery can accurately measure the potential changes of the positive and negative electrodes of the battery relative to the reference electrode, so as to accurately analyze the electrochemical behavior of each electrode.

[0003] Currently, the analysis method for the three - electrode battery is to implant the reference electrode during the production of the battery cell. After the battery cell test is completed, the reference electrode is lithium - plated and then tested. This method implants the reference electrode into the battery cell during battery production, which is only convenient for testing the three - electrodes of fresh batteries. If the battery needs to perform other performance tests first and then test the three - electrodes, the potential of the reference electrode will change, which will affect the measurement of the electrode potential.

[0004] In view of this, providing a three - electrode device for lithium - ion batteries with high accuracy and good universality is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0005] To solve the above - mentioned technical problems, the purpose of the utility model is to provide a three - electrode device for lithium - ion batteries, which does not need to pre - implant the reference electrode into the battery cell, has no influence on the potential change of the reference electrode, the three - electrode data measured are highly reliable and accurate, and has good universality.

[0006] The technical solution provided by the utility model is as follows:

[0007] A three - electrode device for lithium - ion batteries, comprising: an electrode plate, a lower bottom cover, and an upper top cover;

[0008] A groove is provided on the lower bottom cover according to the size of the electrode plate for placing the electrode plate;

[0009] A positive - electrode tab, a negative - electrode tab, and a reference - electrode tab are provided on the lower bottom cover, and correspond to the positive electrode, negative electrode, and reference electrode of the electrode plate one by one;

[0010] A convex groove is provided on the upper top cover according to the size of the pole piece for fixing the pole piece.

[0011] Preferably, a vacuum extraction pipeline and an air valve are further provided on the lower bottom cover;

[0012] The air valve is provided on the vacuum extraction pipeline.

[0013] Preferably, it further includes: an adhesive;

[0014] At the contact positions between the positive electrode tab of the pole piece and the positive electrode tab of the lower bottom cover, between the negative electrode tab of the pole piece and the negative electrode tab of the lower bottom cover, and between the reference electrode of the pole piece and the reference tab of the lower bottom cover, the adhesive is dotted to fix the contact positions of each tab.

[0015] Preferably, it further includes: fixing bolts;

[0016] The fixing bolts are provided at the four corners of the lower bottom cover and the upper top cover.

[0017] Preferably, it further includes: a sealing ring;

[0018] The sealing ring is provided on the lower bottom cover and the upper top cover.

[0019] A three-electrode device for a lithium-ion battery provided by the present utility model includes: a pole piece, a lower bottom cover, and an upper top cover; a groove is provided on the lower bottom cover according to the size of the pole piece for placing the pole piece; a positive electrode tab, a negative electrode tab, and a reference tab are provided on the lower bottom cover, and correspond to the positive electrode, negative electrode, and reference electrode of the pole piece one by one; a convex groove is provided on the upper top cover according to the size of the pole piece for fixing the pole piece; this device does not need to pre-implant a reference electrode into the battery cell, there is no influence on the change of the reference electrode potential, the reliability and accuracy of the three-electrode data measured are high, and it has good universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of the lower bottom cover in an embodiment of the present utility model;

[0022] Figure 2 It is a schematic structural diagram of the upper top cover in an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the technical solutions in the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0024] As Figures 1 to 2 shown, the embodiments of the present utility model provide a three - electrode device for a lithium - ion battery, including: a pole piece 1, a lower bottom cover 2, and an upper top cover 3;

[0025] A groove is provided on the lower bottom cover 2 according to the size of the pole piece 1 for placing the pole piece 1;

[0026] A positive - electrode tab 21, a negative - electrode tab 22, and a reference - electrode tab 23 are provided on the lower bottom cover 2, and correspond one - to - one to the positive electrode, negative electrode, and reference electrode of the pole piece 1;

[0027] A convex groove is provided on the upper top cover 3 according to the size of the pole piece 1 for fixing the pole piece 1.

[0028] In the actual operation process, the positive - electrode pole piece, negative - electrode pole piece, and separator are stacked in the order of separator - negative electrode - separator - positive electrode - separator - negative electrode -... - separator - positive electrode - separator - negative electrode - separator according to the experimental requirements. The reference electrode is inserted at the set position. After pasting the fixing tape, it is placed in the groove of the lower bottom cover. Then, a positive - electrode tab, a negative - electrode tab, and a reference - electrode tab are provided on the lower bottom cover, which correspond one - to - one to the positive electrode, negative electrode, and reference electrode of the pole piece. Then, the upper top cover is closed, and then left standing. After the pole piece is infiltrated, the three - electrode test can be started; this device has relatively low requirements for the operating environment, does not require a protective atmosphere, can be operated only in a dry - gas environment, and does not need to pre - implant the reference electrode into the battery cell. There is no influence on the potential change of the reference electrode. The reliability and accuracy of the three - electrode data measured are high, and it can be used to accurately analyze the deterioration direction of the battery after the test. It can be used to match the tested positive electrode with a fresh negative electrode, or the tested negative electrode with a fresh positive electrode, or the tested positive electrode with the tested negative electrode, which is flexible and has very good universality.

[0029] Preferably, a vacuum - pumping pipeline 24 and a gas valve 25 are further provided on the lower bottom cover;

[0030] The gas valve 25 is provided on the vacuum - pumping pipeline 24.

[0031] During actual operation, when the upper cover is closed, the air valve provided on the vacuum pumping pipeline is opened, and the internal space composed of the upper cover and the lower bottom cover is pumped to a vacuum degree of -90 kPa by the vacuum pumping device, and then the air valve is closed; at this time, the air in the internal space composed of the upper cover and the lower bottom cover is basically exhausted.

[0032] Preferably, it further includes: an adhesive;

[0033] At the contact positions between the positive electrode tab of the electrode sheet and the positive electrode tab of the lower bottom cover, between the negative electrode tab of the electrode sheet and the negative electrode tab of the lower bottom cover, and between the reference electrode of the electrode sheet and the reference tab of the lower bottom cover, the adhesive is dotted to fix the contact positions of each tab.

[0034] During actual operation, before closing the upper cover, at the contact positions between the positive electrode tab of the electrode sheet and the positive electrode tab of the lower bottom cover, between the negative electrode tab of the electrode sheet and the negative electrode tab of the lower bottom cover, and between the reference electrode of the electrode sheet and the reference tab of the lower bottom cover, the adhesive is dotted to fix the contact positions of each tab. There is no need to perform excessive treatment on the electrode sheet, nor to weld the tabs of the electrode sheet (fresh electrode sheet or the electrode sheet of the disassembled battery cell) twice. Only an appropriate amount of adhesive needs to be dotted at the contact positions between the tabs of the electrode sheet and the tooling tabs, and wait for the adhesive to dry to ensure good contact at the contact points; the adhesive used in this embodiment is silver paste.

[0035] Preferably, it further includes: fixing bolts 4;

[0036] The fixing bolts 4 are provided at the four corners of the lower bottom cover 2 and the upper cover 3.

[0037] During actual operation, fixing bolts are provided at the four corners of the lower bottom cover and the upper cover. After fixing the contact positions of each tab, an appropriate amount of electrolyte is injected, and then the upper cover is closed and the fixing bolts are screwed on to ensure the vacuum environment of the electrode sheet between the lower bottom cover and the upper cover, thereby obtaining a good airtight environment.

[0038] Preferably, it further includes: a sealing ring 5;

[0039] The sealing ring 5 is provided on the lower bottom cover 2 and the upper cover 3.

[0040] During actual operation, sealing rings are provided on both the lower bottom cover and the upper cover. After the lower bottom cover and the upper cover are fixed by the fixing bolts, the vacuum environment of the electrode sheet between the lower bottom cover and the upper cover is further ensured.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly disposed on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0042] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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. Therefore, it should not be construed as a limitation to the present invention.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality of" and "several" is two or more, unless otherwise specifically defined.

[0044] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the implementable conditions of the present invention. Therefore, they do not have technical substantial significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the efficacy that the present invention can produce and the purpose that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0045] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three - electrode device for a lithium - ion battery, characterized in that, Including: The electrode plate, the lower bottom cover and the upper top cover; A groove is provided on the lower bottom cover according to the size of the electrode plate for placing the electrode plate; A positive electrode tab, a negative electrode tab and a reference electrode tab are provided on the lower bottom cover, and correspond to the positive electrode, the negative electrode and the reference electrode of the electrode plate one by one; A convex groove is provided on the upper top cover according to the size of the electrode plate for fixing the electrode plate.

2. The lithium-ion battery three-electrode device according to claim 1, wherein A vacuum pumping pipeline and a gas valve are also provided on the lower bottom cover; The gas valve is provided on the vacuum pumping pipeline.

3. The three-electrode device for a lithium-ion battery according to claim 1, wherein Also including: Adhesive; Adhesive is dotted at the contact positions between the positive electrode tab of the electrode plate and the positive electrode tab of the lower bottom cover, the contact positions between the negative electrode tab of the electrode plate and the negative electrode tab of the lower bottom cover, and the contact positions between the reference electrode of the electrode plate and the reference electrode tab of the lower bottom cover for fixing the contact positions of the respective electrode tabs.

4. The lithium-ion battery three-electrode device according to claim 1, characterized in that Also including: Fixing bolts; The fixing bolts are provided at the four corners of the lower bottom cover and the upper top cover.

5. The three-electrode device of a lithium-ion battery according to claim 1, characterized in that, Also including: Sealing rings; The sealing rings are provided on the lower bottom cover and the upper top cover.

Images