Three-electrode battery

Abstract

The utility model discloses a three-electrode battery. The three-electrode battery comprises an insulating shell; the roll core main body is arranged in the insulating shell, the roll core main body is formed by winding a first pole piece, a first diaphragm, a second pole piece and a second diaphragm which are sequentially stacked, the polarity of the first pole piece is opposite to that of the second pole piece, the first pole piece is located on the outermost side of the roll core main body, and the first side of the first pole piece is far away from the first diaphragm; the first side of the first pole piece is provided with a first insulating adhesive layer which is fixedly connected with an insulating shell; the first tab is connected to the first pole piece; the second tab is connected to the second pole piece; the reference electrode comprises a first section and a second section which are connected, the second section is located outside the insulating shell, at least part of the first section is clamped between the insulating shell and the first pole piece, and the first side of the first section is connected to the first insulating adhesive layer. Therefore, the structure of the roll core main body cannot be damaged due to the arrangement of the reference electrode, the roll core main body works more stably, and the detection accuracy of the reference electrode is higher.

Description

Technical Field

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

[0002] Lithium-ion batteries have the advantages of high energy density, fast charge and discharge, long cycle life, and no pollution, and have been widely used in portable electronic devices, communications, energy storage, and electric vehicles. With the development of lithium-ion battery technology, various industries have higher and higher performance requirements, so it is necessary to test and evaluate the electrochemical performance of new battery electrode materials and battery systems.

[0003] Three-electrode technology is a means to test the battery voltage operating range in situ, and can analyze the working potential of the positive and negative electrodes of the battery and the electrode polarization, thereby creating conditions for the study of battery attenuation mechanisms and the optimization of positive and negative electrode material systems. It also has very important guiding significance in battery structure design, pole piece design, positive and negative electrode ratio, material matching, and electrolyte composition optimization.

[0004] A reference electrode needs to be introduced in the three-electrode battery system. For a wound battery, it is generally necessary to disassemble the core and take out the sheets, and then assemble the sheets separately to form a reference electrode to form a three-electrode battery. However, this will destroy the structure of the core to a certain extent and cannot truly reflect the working status of the battery. Utility Model Content

[0005] In order to overcome at least one of the defects of the prior art described above, the utility model provides a three-electrode battery, aiming to solve the problem in the prior art that the core structure is damaged due to the introduction of the reference electrode into the core.

[0006] The technical solution adopted by the utility model to solve the problem is:

[0007] A three-electrode battery comprises: an insulating shell; a winding core body, which is arranged in the insulating shell, and the winding core body is formed by winding a first pole piece, a first diaphragm, a second pole piece and a second diaphragm which are stacked in sequence, the first pole piece and the second pole piece have opposite polarities, the first pole piece is located at the outermost side of the winding core body, the first side of the first pole piece is away from the first diaphragm, and the first side of the first pole piece is provided with a first insulating rubber layer for fixed connection with the insulating shell; a first pole ear, which is connected to the first pole piece; a second pole ear, which is connected to the second pole piece; a reference electrode, the reference electrode comprising a first segment and a second segment connected, the second segment extending out of the insulating shell, the first segment at least partially sandwiched between the insulating shell and the first pole piece, and the first side of the first segment is connected to the first insulating rubber layer.

[0008] According to some embodiments of the present invention, the three-electrode battery further includes a third diaphragm, wherein the third diaphragm is sandwiched between the second side of the first segment and the insulating shell.

[0009] According to some embodiments of the present invention, a second insulating adhesive layer is further provided between the third diaphragm and the first pole piece.

[0010] According to some embodiments of the present invention, a reinforcing glue is further provided between the first segment and the first pole piece.

[0011] According to some embodiments of the present invention, the first pole piece is a positive pole piece, and the first pole lug is a positive pole lug; the second pole piece is a negative pole piece, and the second pole lug is a negative pole lug.

[0012] According to some embodiments of the utility model, the winding core body is formed with two oppositely arranged pole ear sides, the first pole ear and the second pole ear are connected to the pole ear sides, and the winding core body also has an external connection side connected between the two pole ear sides, and the second segment extends out of the insulating shell from the external connection side.

[0013] According to some embodiments of the present invention, the first pole lug and the second pole lug are parallel to each other in a first plane, and the reference electrode and the first pole lug are perpendicular to each other in the first plane.

[0014] According to some embodiments of the utility model, the reference electrode includes a reference electrode tab and a lithium sheet, both of which are in sheet shape, the lithium sheet is arranged at the first end of the reference electrode tab, the first segment includes the lithium sheet and the first end of the reference electrode tab, the second end of the reference electrode tab extends out of the insulating shell, and the second segment includes the second end of the reference electrode tab.

[0015] According to some embodiments of the present invention, the lithium sheet includes a first folding portion and a second folding portion, and the first folding portion and the second folding portion are folded relative to one end of the reference electrode tab.

[0016] According to some embodiments of the present invention, the insulating shell is an aluminum-plastic film shell.

[0017] In summary, the three-electrode battery provided by the utility model has at least the following technical effects:

[0018] The first pole piece is located at the outermost side of the winding core body, and a first insulating rubber layer needs to be provided on the first side of the first pole piece to be fixedly connected to the insulating shell. More importantly, the first insulating rubber layer can also be directly connected to the first side of the first segment, and the first segment and the first pole piece are insulated, thereby achieving the purpose of setting the reference electrode at the outermost side of the winding core body. In this way, the structure of the winding core body will not be damaged by the setting of the reference electrode, so that the overall structure of the three-electrode battery can be simpler, the operation is more stable, and the detection accuracy of the reference electrode is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the insulating housing of an embodiment of the utility model;

[0020] Figure 2 This is a schematic structural diagram of a three-electrode battery (the insulating housing and the third diaphragm are not shown) according to an embodiment of the utility model;

[0021] Figure 3 It is a schematic structural diagram of a three-electrode battery (insulating shell not shown) according to an embodiment of the utility model.

[0022] The meanings of the reference numerals are as follows:

[0023] 1. Insulating shell; 11. Receiving pit; 2. Winding core body; 21. First pole piece; 3. First pole ear; 4. Second pole ear; 5. Reference electrode; 51. First segment; 52. Second segment; 6. First insulating rubber layer; 7. Third diaphragm. DETAILED DESCRIPTION

[0024] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0025] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0027] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0028] See also Figures 1 to 3 The utility model discloses a three-electrode battery, comprising an insulating shell 1, a winding core body 2, a first pole ear 3, a second pole ear 4 and a reference electrode 5; the winding core body 2 is arranged on the insulating shell 1, and the winding core body 2 is formed by winding a first pole piece 21, a first diaphragm, a second pole piece and a second diaphragm which are stacked in sequence, the polarities of the first pole piece 21 and the second pole piece are opposite, the first pole piece 21 is located at the outermost side of the winding core body 2, the first side of the first pole piece 21 is far away from the first diaphragm, the first side of the first pole piece 21 is provided with a first insulating adhesive layer 6 for fixedly connecting the insulating shell 1, the first pole ear 3 is connected to the first pole piece 21, the second pole ear 4 is connected to the second pole piece, the first pole ear 3 and the first pole piece 21 have the same polarity, and the second pole ear 4 and the second pole piece have the same polarity; the reference electrode 5 includes a first segment 51 and a second segment 52 which are connected, the second segment 52 extends out of the insulating shell 1, the first segment 51 is at least partially sandwiched between the insulating shell 1 and the first pole piece 21, and the first side of the first segment 51 is connected to the first insulating adhesive layer 6.

[0029] In a three-electrode battery provided in this embodiment, the first pole piece 21 is located at the outermost side of the core body 2, and a first insulating rubber layer 6 needs to be arranged on the first side of the first pole piece 21 to be fixedly connected to the insulating shell 1. More importantly, the first insulating rubber layer 6 can also be directly connected to the first side of the first segment 51, and the first segment 51 and the first pole piece 21 are insulated, thereby achieving the purpose of arranging the reference electrode 5 at the outermost side of the core body 2. In this way, the structure of the core body 2 will not be damaged by the arrangement of the reference electrode 5, so that the overall structure of the three-electrode battery can be simpler, the operation is more stable, and the detection accuracy of the reference electrode 5 is higher.

[0030] Preferably, in this embodiment, after one side of the first segment 51 is directly connected to the first insulating adhesive layer 6 , a reinforcing adhesive may be provided between the first segment 51 and the first pole piece 21 to further improve the connection stability between the first segment 51 and the first pole piece 21 .

[0031] like Figure 1 and Figure 3 As shown, further, in this embodiment, the three-electrode battery also includes a third diaphragm 7, and the third diaphragm 7 is located between the insulating shell 1 and the first segment 51, so as to avoid direct contact between the first segment 51 and the insulating shell 1. In this way, the working stability of the first segment 51 is guaranteed, and the reference electrode 5 can always be in a good working condition.

[0032] Preferably, in this embodiment, the surface of the insulating housing 1 is provided with two receiving pits 11 for receiving the winding core body 2; of course, in some other embodiments, the number of receiving pits can be, but is not limited to, 1, 3, 4, etc., which can be selected according to actual needs and is not limited to this. Specifically, the third diaphragm 7 is in direct contact with the side wall of the receiving pit 11.

[0033] Preferably, in this embodiment, a second insulating adhesive layer is further provided between the third diaphragm 7 and the first pole piece 21 , so that a stable connection can be formed between the third diaphragm 7 and the first pole piece 21 .

[0034] Preferably, in this embodiment, the first pole piece 21 is a positive pole piece, and the first pole tab 3 is a positive pole tab; the second pole piece is a negative pole piece, and the second pole tab 4 is a negative pole tab. The strength of the positive pole piece is better than that of the negative pole piece, and the positive pole piece is arranged at the outermost side of the winding core body 2, which is conducive to ensuring and improving the safety performance of the winding core. More specifically, in this embodiment, the positive pole piece is aluminum foil, and the negative pole piece is copper foil.

[0035] It should be noted that, in some other embodiments, the first pole piece 21 can be a negative pole piece, the second pole piece can be a positive pole piece, the first pole ear 3 can be a corresponding negative pole ear, and the second pole ear 4 can be a corresponding positive pole ear, that is, the negative pole piece can be arranged on the outermost side of the winding core body 2, and it can be selected according to actual needs.

[0036] like Figure 2 and Figure 3 As shown, preferably, in this embodiment, the core body 2 is formed with two oppositely arranged pole ear sides, the first pole ear 3 and the second pole ear 4 are connected to the pole ear sides, the core body 2 also has an external connection side connected between the two pole ear sides, and the second segment 52 extends from the external connection side to the insulating shell 1, so that the second segment 52, the first pole ear 3 and the second pole ear 4 are avoided from being led out from the same side of the core body 2, which is beneficial to packaging. Preferably, in this embodiment, the first pole ear 3 and the second pole ear 4 are parallel to each other in the first plane, the reference electrode 5 and the first pole ear 3 are perpendicular to each other in the first plane, and the first plane is the projection of the large surface of the core body. It can be understood that the first pole ear 3 and the second pole ear 4 can be located on the same side of the core body 2, or on different sides of the core body 2, which can be selected according to actual needs.

[0037] Preferably, in this embodiment, the reference electrode 5 includes a reference tab and a lithium tab both in sheet form, the lithium tab is disposed at the first end of the reference tab, the first segment 51 includes the lithium tab and the first end of the reference tab, the second end of the reference tab extends out of the insulating housing 1, and the second segment 52 includes the second end of the reference tab. The metal lithium tab has a stable potential, and does not have the defects of the lithium plating layer of the reference electrode 5 in the prior art, such as easy shedding and short life. In addition, compared with the filamentary metal structure of the reference electrode 5 in the prior art, the sheet structure of the metal lithium tab has higher strength and stability.

[0038] Preferably, in this embodiment, the lithium sheet includes a first folded portion and a second folded portion, and the first folded portion and the second folded portion are folded relative to one end of the reference tab, so as to further improve the overall strength and stability.

[0039] Preferably, in this embodiment, the lithium sheet has a thickness of 20 to 100 μm, a length of 2 to 6 mm, and a width that is twice the width of a reference tab. The reference tab is a tab of the same type as the winding core, including one of a nickel tab, an aluminum tab, and an aluminum-to-nickel tab.

[0040] Preferably, in this embodiment, the insulating shell 1 is an aluminum-plastic film shell.

[0041] It can be understood that, in this embodiment, the first insulating adhesive layer 6, the second insulating adhesive layer and the fixing adhesive are all insulating high-temperature adhesives.

[0042] This embodiment also provides a method for producing a three-electrode battery;

[0043] S0, attaching a first insulating adhesive layer 6 to a first side of the first electrode sheet 21;

[0044] S1. Cut the lithium sheet to the required size, fold the cut lithium sheet in half and clamp it on one end of the reference electrode tab;

[0045] S3, connecting one side of the first segment 51 (i.e., the segment provided with the lithium sheet) of the assembled reference electrode 5 to the first insulating adhesive layer 6, and covering the other side of the first segment 51 with a third diaphragm 7, and fixing the third diaphragm 7 with a second insulating adhesive layer;

[0046] S4, top sealing is performed at the first electrode ear 3 and the second electrode ear 4, the insulating housing 1 is connected to the assembled winding core, and the second segment 52 of the reference electrode 5 is extended out of the insulating housing 1, and side sealing is performed at the reference electrode 5;

[0047] S5, battery cell filling, formation and molding.

[0048] In summary, the three-electrode battery disclosed in the present utility model can at least bring the following beneficial technical effects:

[0049] 1) The reference electrode 5 is arranged at the outermost side of the winding core body 2, and the structure of the winding core body 2 will not be damaged by the arrangement of the reference electrode 5, so that the overall structure of the three-electrode battery is simpler, the operation is more stable, and the detection accuracy of the reference electrode 5 is higher. ;

[0050] 2) A reinforcing glue is provided between the first segment 51 and the first pole piece 21 to further improve the connection stability between the first segment 51 and the first pole piece 21;

[0051] 3) The third diaphragm 7 is located between the insulating housing 1 and the first segment 51 to avoid direct contact between the first segment 51 and the insulating housing 1. In this way, the working stability of the first segment 51 is guaranteed and the reference electrode 5 can always be in a good working state;

[0052] 4) Avoid leading the second segment 52, the first pole tab 3 and the second pole tab 4 from the same side of the winding core body 2, which is beneficial to packaging;

[0053] 5) The metal lithium sheet has a stable potential and does not have the defects of the lithium plating layer of the reference electrode 5 in the prior art, such as easy shedding and short life. In addition, compared with the filamentary metal structure of the reference electrode 5 in the prior art, the sheet structure of the metal lithium sheet has higher strength and stability.

[0054] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A three-electrode battery, characterized in that: include: Insulating housing (1); A winding core body (2) is arranged on the insulating shell (1), the winding core body (2) is formed by winding a first pole piece (21), a first diaphragm, a second pole piece and a second diaphragm which are stacked in sequence, the first pole piece (21) and the second pole piece have opposite polarities, the first pole piece (21) is located at the outermost side of the winding core body (2), the first side of the first pole piece (21) is away from the first diaphragm, and the first side of the first pole piece (21) is provided with a first insulating rubber layer (6) for fixed connection with the insulating shell (1); A first pole lug (3) connected to the first pole piece (21); A second pole lug (4), connected to the second pole piece; A reference electrode (5), the reference electrode (5) comprising a first segment (51) and a second segment (52) connected to each other, the second segment (52) extending out of the insulating shell (1), the first segment (51) at least partially sandwiched between the insulating shell (1) and the first pole piece (21), and a first side of the first segment (51) connected to the first insulating rubber layer (6).

2. A three-electrode battery according to claim 1, characterized in that: The three-electrode battery further comprises a third diaphragm (7), wherein the third diaphragm (7) is sandwiched between the second side of the first segment (51) and the insulating housing (1).

3. A three-electrode battery according to claim 2, characterized in that: A second insulating rubber layer is also provided between the third diaphragm (7) and the first pole piece (21).

4. A three-electrode battery according to claim 1, characterized in that: A reinforcing glue is also provided between the first segment (51) and the first pole piece (21).

5. A three-electrode battery according to claim 1, characterized in that: The first pole piece (21) is a positive pole piece, and the first pole lug (3) is a positive pole lug; the second pole piece is a negative pole piece, and the second pole lug (4) is a negative pole lug.

6. A three-electrode battery according to claim 1, characterized in that: The winding core body (2) is formed with two oppositely arranged pole ear sides, the first pole ear (3) and the second pole ear (4) are connected to the pole ear sides, the winding core body (2) also has an external connection side connected between the two pole ear sides, and the second segment (52) extends from the external connection side to the insulating shell (1).

7. A three-electrode battery according to claim 6, characterized in that: The first pole tab (3) and the second pole tab (4) are parallel to each other in a first plane, and the reference electrode (5) and the first pole tab (3) are perpendicular to each other in the first plane.

8. A three-electrode battery according to claim 1, characterized in that: The reference electrode (5) comprises a reference electrode tab and a lithium sheet both in sheet form, the lithium sheet being arranged at a first end of the reference electrode tab, the first segment (51) comprising the lithium sheet and the first end of the reference electrode tab, the second end of the reference electrode tab extending out of the insulating housing (1), and the second segment (52) comprising the second end of the reference electrode tab.

9. A three-electrode battery according to claim 8, characterized in that: The lithium sheet includes a first folding portion and a second folding portion, and the first folding portion and the second folding portion are folded relative to one end of the reference electrode tab.

10. A three-electrode battery according to any one of claims 1 to 9, characterized in that: The insulating shell (1) is an aluminum-plastic film shell.

Images