CN220121921U

CN220121921U - Three-electrode battery

Info

Publication number: CN220121921U
Application number: CN202321697545.3U
Authority: CN
Inventors: 黄娜; 刘子文; 成斌
Original assignee: Hubei Eve Power Co Ltd
Current assignee: Hubei Eve Power Co Ltd
Priority date: 2023-06-29
Filing date: 2023-06-29
Publication date: 2023-12-01
Anticipated expiration: 2033-06-29

Abstract

The utility model discloses a three-electrode battery. The three-electrode battery includes: the shell is provided with an explosion-proof valve; a core pack fitted inside the housing; the reference electrode is wound on the core bag, and one end of the reference electrode penetrates through the explosion-proof valve to extend out of the shell. According to the utility model, the reference electrode is wound on the core bag, one end of the reference electrode penetrates through the explosion-proof valve and extends out of the shell, the structure of the existing battery is fully utilized, the process for manufacturing the three-electrode battery is optimized, the three-electrode battery is formed under the condition that the original structure of the battery shell is not damaged, the modification of the original structure of the battery in the process of manufacturing the three-electrode battery is reduced, and the phenomenon that oxidation or volatilization of electrolyte is easy to occur in the battery can be effectively avoided.

Description

Three-electrode battery

Technical Field

The utility model relates to the technical field of lithium ion batteries, in particular to a three-electrode battery.

Background

The lithium ion battery has the advantages of high energy density, long cycle life and the like, and is widely applied to the fields of electric automobiles and the like. For a power battery, the life decay is finally represented by capacity decay or power performance degradation, and the decay sources can be attributed to positive or negative electrode decay. In the design and research process of the battery, the influence of the positive electrode and the negative electrode on the capacity change of the battery needs to be independently analyzed, and the influence cannot be realized in the whole battery with two electrodes, so that a reference electrode needs to be introduced into the whole battery, and the potential and the impedance of the positive electrode and the negative electrode relative to the reference electrode in the whole battery are respectively measured, so that the monitoring of the performance of the positive electrode and the negative electrode is realized in the charging and discharging process, and the electrochemical behaviors of the positive electrode and the negative electrode are effectively distinguished.

In the prior art, when a three-electrode battery is manufactured, a hole is usually directly formed in a shell of the battery, and then a reference electrode arranged on a core bag is led out or inserted into the core bag, so that oxidation or volatilization of electrolyte is easy to occur in the battery.

Disclosure of Invention

In order to overcome at least one of the defects described in the prior art, the utility model provides a three-electrode battery, which can effectively avoid the condition that oxidation or volatilization of electrolyte is easy to occur in the battery.

In one embodiment of the present utility model, a three-electrode battery includes: the shell is provided with an explosion-proof valve; a core pack fitted inside the housing; the reference electrode is wound on the core bag, and one end of the reference electrode penetrates through the explosion-proof valve to extend out of the shell.

In the three-electrode battery, the reference electrode is wound on the core bag, one end of the reference electrode penetrates through the explosion-proof valve to extend out of the shell, the structure of the existing battery is fully utilized, the process for manufacturing the three-electrode battery is optimized, the three-electrode battery is formed under the condition that the original shell of the battery is not damaged, the modification of the original structure of the battery during manufacturing the three-electrode battery is reduced, and oxidation or volatilization of electrolyte in the battery can be effectively avoided.

According to some embodiments of the utility model, the explosion-proof valve is provided with a through hole, and a sealing piece is connected between the through hole and the reference electrode in a sealing way.

According to some embodiments of the utility model, the reference electrode comprises a wire comprising a coiled section coiled around a negative or positive electrode of the core pack and an extension connected to one end of the coiled section, the extension extending through the explosion proof valve to the outside of the housing.

According to some embodiments of the utility model, the metal wire is a copper wire.

According to some embodiments of the utility model, the separator further comprises a separator comprising a first insulation section wound on the negative or positive electrode of the core pack and a second insulation section wound on a side of the first insulation section remote from the core pack, the winding section being disposed between the first and second insulation sections.

According to some embodiments of the utility model, the length of the first insulating section is greater than the perimeter of the core pack.

According to some embodiments of the utility model, the width of the membrane is smaller than the width of the core pack.

According to some embodiments of the utility model, the number of the reference electrodes is greater than one, and the reference electrodes are arranged at intervals.

According to some embodiments of the utility model, a portion of the reference electrode extending outside the housing is sleeved with a protective sleeve.

According to some embodiments of the utility model, the explosion-proof valve is located on the same side of the housing as the positive tab and the negative tab.

In summary, the three-electrode battery provided by the utility model has the following technical effects:

the three-electrode battery is formed under the condition that the original shell of the battery is not damaged, the improvement of the original structure of the battery during manufacturing of the three-electrode battery is reduced, and oxidation or volatilization of electrolyte in the battery can be effectively avoided.

Drawings

Fig. 1 is a schematic structural view of a three-electrode battery according to an embodiment of the present utility model;

fig. 2 is a schematic view of a three-electrode battery according to an embodiment of the present utility model;

FIG. 3 is a schematic view of a core pack according to an embodiment of the present utility model;

fig. 4 is a schematic view of a core pack according to an embodiment of the present utility model.

Wherein the reference numerals have the following meanings:

1. a housing; 11. an explosion-proof valve; 12. a through hole; 13. a seal; 14. a positive electrode tab; 15. a negative electrode ear; 2. a core pack; 3. a reference electrode; 31. a wire; 32. a winding section; 33. an extension section; 34. a diaphragm; 35. a first insulating section; 36. and a second insulating section.

Detailed Description

For a better understanding and implementation, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model.

In the description of the present utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Unless defined otherwise, 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 utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model.

Referring to fig. 1 and 2, the present utility model discloses a three-electrode battery, comprising: the device comprises a shell 1, a core pack 2 and a reference electrode 3, wherein in some embodiments, the shell 1 is provided with an explosion-proof valve 11, the core pack 2 is assembled inside the shell 1, optionally, the core pack 2 is formed by overlapping a positive electrode, a diaphragm 34 and a negative electrode in half and winding, the reference electrode 3 is wound on the core pack 2, and one end of the reference electrode 3 extends out of the shell 1 through the explosion-proof valve 11. Optionally, the reference electrode 3 is wound on the core bag 2, and one end of the reference electrode 3 passes through the explosion-proof valve 11 to extend out of the shell 1, so that the structure of the existing battery is fully utilized, the process for manufacturing the three-electrode battery is optimized, the three-electrode battery is formed under the condition that the original shell of the battery is not damaged, the modification of the original structure of the battery during manufacturing the three-electrode battery is reduced, and the oxidation or the volatilization of electrolyte in the battery can be effectively avoided.

Referring to fig. 2, in some embodiments, the explosion-proof valve 11 is provided with a through hole 12, and a sealing member 13 is hermetically connected between the through hole 12 and the reference electrode 3. Specifically, the explosion-proof valve 11 is covered on the exhaust hole of the battery, and optionally, through the through hole 12 on the explosion-proof valve 11 and the internal connection of the casing 1, the reference electrode 3 can pass through the through hole 12 on the explosion-proof valve 11 and extend to the outside of the casing 1, so that the original casing 1 of the battery can be prevented from being damaged when the three-electrode battery is manufactured, and a sealing element 13 is hermetically connected between the through hole 12 and the reference electrode 3, so that the gap between the through hole 12 and the reference electrode 3 is sealed, and oxidation or volatilization of electrolyte in the battery is avoided. Optionally, the sealing element 13 may be an elastic element, and is disposed on the reference electrode 3 in a penetrating manner, and is in interference fit with the through hole 12, so as to realize sealing, optionally, the sealing element 13 may be formed by solidifying a material refilled into the through hole 12 after the reference electrode 3 passes through the through hole 12, optionally, after the reference electrode 3 passes through the through hole 12, AB glue is filled into the through hole 12, and baking is performed after the AB glue dries, so as to form the sealing element 13 in sealing connection between the through hole 12 and the reference electrode 3.

Referring to fig. 3 and 4, in some embodiments, the reference electrode 3 includes a wire 31, the wire 31 includes a winding section 32 and an extension section 33 connected to one end of the winding section 32, the winding section 32 is wound around the negative electrode or the positive electrode of the core pack 2, and the extension section 33 extends out of the case 1 through the explosion-proof valve 11. Optionally, the diameter of the wire 31 is 0.1mm, specifically, the wire 31 is too small in diameter and is easy to break, the wire 31 is too large in diameter and is easy to affect the situation that the positive electrode and the negative electrode of the battery core take off or intercalate lithium ions, and optionally, the length of the winding section 32 of the wire 31 is larger than the perimeter of the core pack 2, so that the winding section 32 of the wire 31 can be wound on the periphery of the core pack 2; optionally, the metal wire 31 is insulated from the negative electrode or the positive electrode of the core pack 2, so as to avoid the occurrence of abnormal reference electrode 3 caused by short circuit between the metal wire 31 and the negative electrode or the positive electrode of the core pack 2, which cannot be used; optionally, the winding section 32 and the extending section 33 are two adjacent parts on the same wire 31, that is, the winding section 32 and the extending section 33 are integrally arranged, that is, one part of the wire 31 is wound on the negative electrode or the positive electrode of the core pack 2, and the other part extends to the outside of the casing 1 through the explosion-proof valve 11.

In some embodiments, the surface of the coiled section 32 is plated with a lithium layer. Optionally, the surface of the portion of the metal wire 31 disposed in the housing 1 is plated with a lithium layer, so that the situation that the negative electrode or the positive electrode in the region where the reference electrode 3 is located is deactivated and lithium is separated due to the influence of lithium ions and the overvoltage of the negative electrode or the positive electrode in the region where the reference electrode 3 is located is effectively avoided.

In some embodiments, the wire 31 is a copper wire. Optionally, the metal wire 31 is a copper wire with the diameter of 0.1mm, and optionally, the copper wire is an enameled wire copper wire; optionally, the two ends of the copper wire are soaked in concentrated sulfuric acid for 30min, then cleaned with purified water and ethanol, and then put into a sealing bag to avoid oxidization, and then taken out when being assembled, for example, the two ends are polished by using sand paper when the use time interval is longer. Optionally, the portion of the copper wire wound around the core package 2 is plated with lithium, that is, the winding section 32 of the copper wire is plated with lithium, so that the situations that the negative electrode or the positive electrode in the area where the reference electrode 3 is located is influenced by the removal or intercalation of lithium ions and the negative electrode or the positive electrode in the area where the reference electrode 3 is located is over-pressed, so that the negative electrode or the positive electrode is deactivated and lithium is separated can be effectively avoided.

Referring to fig. 3 and 4, in some embodiments, the separator 34 further includes a separator 34, the separator 34 includes a first insulation section 35 and a second insulation section 36, the first insulation section 35 is wound on the negative electrode or the positive electrode of the core pack 2, the second insulation section 36 is wound on a side of the first insulation section 35 away from the core pack 2, and the winding section 32 is disposed between the first insulation section 35 and the second insulation section 36. Optionally, the first insulation section 35 of the diaphragm 34 is wound on the negative electrode or the positive electrode of the core pack 2, then the winding section 32 of the metal wire 31 is wound on the side, far away from the core pack 2, of the first insulation section 35, and then the second insulation section 36 of the diaphragm 34 is wound on the side, far away from the core pack 2, of the metal wire 31, so that the metal wire 31 is wrapped between the first insulation section 35 and the second insulation section 36, and short circuit between the metal wire 31 and the negative electrode or the positive electrode of the core pack 2 is avoided, and the reference electrode 3 is abnormal and cannot be used; optionally, the first insulating section 35 of the diaphragm 34 is wound on the negative electrode or the positive electrode of the core pack 2, then the winding section 32 of the wire 31 is stuck on the side, close to the core pack 2, of the second insulating section 36 of the diaphragm 34 by green glue, and then the second insulating section 36 of the diaphragm 34 is wound on the side, far from the core pack 2, of the first insulating section 35, so that the winding section 32 of the wire 31 is wound on the side, far from the core pack 2, of the first insulating section 35 and is located between the first insulating section 35 and the second insulating section 36, that is, the wire 31 is wrapped between the first insulating section 35 and the second insulating section 36, so as to avoid the wire 31 from forming a short circuit with the negative electrode or the positive electrode of the core pack 2, which results in abnormal use of the reference electrode 3.

In some embodiments, the length of the first insulation segment 35 is greater than the perimeter of the core pack 2. Specifically, the length of the first insulating section 35 of the diaphragm 34 is greater than the perimeter of the core pack 2, so that the first insulating section 35 of the diaphragm 34 can enclose a complete interlayer around the negative electrode or the positive electrode of the core pack 2, damage to the diaphragm 34 after compacting the metal wire 31 and the diaphragm 34 by hot pressing is avoided, the metal wire 31 and the negative electrode or the positive electrode of the core pack 2 are caused to be shorted, the process of manufacturing the three-electrode battery is optimized, and the success rate of manufacturing the three-electrode battery is improved.

In some embodiments, the length of the second insulating section 36 is equal to or greater than the length of the winding section 32 of the wire 31, so that the second insulating section 36 of the diaphragm 34 can completely encase the winding section 32 of the wire 31, avoiding causing a short circuit, optionally, the second insulating section 36 of the diaphragm 34 after winding is completed, the end of the second insulating section 36 and/or the winding section 32 of the wire 31 is fixed to the core pack 2 using an insulating adhesive paper, optionally, the end of the second insulating section 36 and/or the winding section 32 is adhered to a diaphragm wound on the core pack 2 using an insulating adhesive paper to fixedly wind the reference electrode 3 on the core pack 2.

In some embodiments, the width of the septum 34 is less than the width of the core wrap 2 to avoid the septum 34 being too wide to affect subsequent welds; optionally, the area where the wire 31 is disposed does not exceed the position where the diaphragm 34 is wrapped, so as to avoid a short-circuit accident.

Referring to fig. 1, 2, 3 and 4, in some embodiments, the number of reference electrodes 3 is greater than one, and the reference electrodes 3 are disposed at intervals. Optionally, the number of the reference electrodes 3 is three, and the three reference electrodes 3 are arranged at intervals, that is, the three reference electrodes 3 are separated from each other and are not in contact with each other, when an abnormality occurs in one reference electrode 3, the rest of the reference electrodes 3 can still be normally used. Optionally, each reference electrode 3 corresponds to a copper wire, and a diaphragm 34 is disposed corresponding to each copper wire, that is, 3 diaphragms 34 are also disposed for avoiding short circuits of the copper wires, specifically, a first insulation section 35 of each diaphragm 34 is wound on a negative electrode or a positive electrode of the core pack 2, the winding section 32 of the metal wire 31 is adhered to a side, close to the core pack 2, of the second insulation section 36 of the diaphragm 34 through green glue, and then the second insulation section 36 is wound on a side, far from the core pack 2, of the first insulation section 35, so that the winding section 32 of each metal wire 31 is wound on a side, far from the core pack 2, of the corresponding first insulation section 35; optionally, the width of the diaphragm 34 is smaller than that of the core pack 2, and it is capable of satisfying that three copper wires are arranged on a film at intervals, that is, three copper wires are all arranged on one diaphragm, specifically, a first insulation section 35 of the diaphragm 34 is wound on a negative electrode or a positive electrode of the core pack 2, then the winding sections 32 of three wires 31 are respectively adhered on one side of the second insulation section 36 of the diaphragm 34, which is close to the core pack 2, through green glue, and then the second insulation section 36 of the diaphragm 34 is wound on one side of the first insulation section 35, which is far from the core pack 2, so that the winding sections 32 of three wires 31 are all wound on one side of the first insulation section 35, which is far from the core pack 2, and are located between the first insulation section 35 and the second insulation section 36, that is, the winding sections 32 of three wires 31 are all wrapped between the first insulation section 35 and the second insulation section 36.

In some embodiments, the part of the reference electrode 3 extending to the outside of the casing 1 is sleeved with a protective sleeve to protect the part of the reference electrode 3 exposed to the outside of the casing 1, optionally, the protective sleeve is made of an insulating material, when the reference electrode 3 is a plurality of reference electrodes, only one reference electrode 3 is needed to be used for a single test, only the reference electrode 3 needs to be taken out from the protective sleeve at this time, a test device is connected, other reference electrodes 3 are kept in the original state, mutual interference between the reference electrodes 3 can be effectively avoided, the reference electrodes 3 extending from the same explosion-proof valve 11 can be independently used, optionally, the part of each reference electrode 3 extending to the outside of the casing 1 is sleeved with a protective sleeve, when one reference electrode 3 is abnormal, the rest of the reference electrodes 3 can still be normally used, the abnormal reference electrode 3 can be sleeved with a protective sleeve, the abnormal reference electrodes 3 are prevented from contacting the normal reference electrodes 3, the normal test of the reference electrodes 3 is affected, and the reference electrodes 3 extending from the same explosion-proof valve 11 can be independently used at any time.

Referring to fig. 1 and 2, in some embodiments, the explosion-proof valve 11 is located on the same side of the casing 1 as the positive tab 14 and the negative tab 15, so that the positive tab 14, the negative tab 15 and the reference electrode 3 extending from the explosion-proof valve 11 are located on the same side, thereby facilitating layout of the battery and wiring of test equipment and the battery; when a plurality of batteries form a battery pack for testing, the parts (namely the positive electrode lug 14, the negative electrode lug 15 and the reference electrode 3) of the external equipment are positioned on the same end face, so that the external equipment is convenient to connect with the three-electrode battery, and the three-electrode battery can be tested conveniently.

Referring to fig. 1, 2, 3 and 4, in some embodiments, a casing 1, a plurality of metal wires 31, a core pack 2 and a diaphragm 34 are prepared in advance, optionally, the core pack 2 is formed by overlapping and doubling up a positive electrode, the diaphragm 34 and a negative electrode, optionally, the casing 1 is made of aluminum, optionally, the metal wires 31 are copper wires with the thickness of 0.1mm, optionally, the two ends of the copper wires are soaked in concentrated sulfuric acid for 30min, then cleaned with purified water and ethanol, and then put into a sealing bag to avoid oxidization, and then taken out when assembled, for example, the two ends are polished by using sand paper if the time interval is longer; optionally, the separator 34 is a separator 34 on the negative electrode of the core pack 2, optionally, the first insulation section 35 of the separator 34 is wound on the negative electrode or the positive electrode of the core pack 2, then the winding sections 32 of the plurality of wires 31 are respectively stuck on one side, close to the core pack 2, of the second insulation section 36 of the separator 34 through green glue, then the second insulation section 36 of the separator 34 is wound on one side, far away from the core pack 2, of the first insulation section 35, so that the winding sections 32 of the plurality of wires 31 are wound on one side, far away from the core pack 2, of the first insulation section 35 and are positioned between the first insulation section 35 and the second insulation section 36, namely, the winding sections 32 of the plurality of wires 31 are wrapped between the first insulation section 35 and the second insulation section 36, and the length of the optional first insulation section 35 is larger than the circumference of the core pack 2, so that the first insulation section 35 can be wound on one side, far away from the core pack 2, of the first insulation section 35 and the positive electrode or the negative electrode pack 2 can be completely compressed, and the separator 31 can be prevented from being damaged by the periphery of the battery 2, and the separator is manufactured. Optionally, the width of the diaphragm 34 is smaller than the width of the core pack 2 to avoid the diaphragm 34 being too wide to affect subsequent welding; optionally, the wires 31 are disposed at intervals, that is, the wires 31 are separated from each other and do not contact with each other, when an abnormality occurs in a certain wire 31, the rest of the wires 31 can still be used normally, optionally, after the second insulation section 36 of the diaphragm 34 is wound, an insulating adhesive tape is used to adhere the end of the second insulation section 36 and/or the winding section 32 of the wire 31 to a diaphragm wound on the core pack 2, so as to fixedly wind the reference electrode 3 on the core pack 2. And then carrying out hot pressing and pre-welding on the core package 2, opening a through hole 12 on a cover plate of the explosion-proof valve 11 of the shell 1, leading out an extension section 33 of the metal wire 31 from the through hole 12 of the explosion-proof valve 11, then assembling the core package 2 into the shell 1, filling AB glue into the through hole 12, baking after the AB glue dries, sealing a gap between the through hole 12 and the reference electrode 3, and sleeving a protective sleeve on a part of the reference electrode 3 exposed out of the shell 1 to manufacture a three-electrode battery, wherein the three-electrode battery alone or together with other three-electrode batteries can form a battery pack for analyzing the capacity attenuation of the lithium ion power battery.

The technical means disclosed by the scheme of the utility model is not limited to the technical means disclosed by the embodiment, and also comprises the technical scheme formed by any combination of the technical features. It should be noted that modifications and adaptations to the utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims

1. A three-electrode battery, comprising:

a housing (1), the housing (1) being provided with an explosion-proof valve (11);

-a core pack (2), the core pack (2) being fitted inside the housing (1);

the reference electrode (3) is wound on the core bag (2), and one end of the reference electrode (3) extends out of the shell (1) through the explosion-proof valve (11).

2. The three-electrode battery according to claim 1, wherein: the explosion-proof valve (11) is provided with a through hole (12), and a sealing piece (13) is connected between the through hole (12) and the reference electrode (3) in a sealing way.

3. The three-electrode battery according to claim 1 or 2, wherein: the reference electrode (3) comprises a metal wire (31), the metal wire (31) comprises a winding section (32) and an extension section (33) connected to one end of the winding section (32), the winding section (32) is wound on the negative electrode or the positive electrode of the core pack (2), and the extension section (33) extends out of the shell (1) through the explosion-proof valve (11).

4. A three-electrode battery according to claim 3, characterized in that: the metal wire (31) is a copper wire.

5. A three-electrode battery according to claim 3, characterized in that: still include diaphragm (34), diaphragm (34) include first insulating section (35) and second insulating section (36), first insulating section (35) are convoluteed on the negative pole or the anodal of core package (2), second insulating section (36) are convoluteed first insulating section (35) keep away from one side of core package (2), coiling section (32) set up in between first insulating section (35) and second insulating section (36).

6. The three-electrode battery according to claim 5, wherein: the length of the first insulation section (35) is greater than the perimeter of the core pack (2).

7. The three-electrode battery according to claim 5, wherein: the width of the diaphragm (34) is smaller than the width of the core pack (2).

8. The three-electrode battery according to claim 1, wherein: the number of the reference electrodes (3) is larger than one, and the reference electrodes (3) are arranged at intervals.

9. The three-electrode battery according to claim 1, wherein: and a part of the reference electrode (3) extending out of the shell (1) is sleeved with a protective sleeve.

10. The three-electrode battery according to claim 1, wherein: the explosion-proof valve is characterized by further comprising a positive lug (14) connected to the positive pole of the core pack (2) and a negative lug (15) connected to the negative pole of the core pack (2), wherein the explosion-proof valve (11) is positioned on the same side of the shell (1) as the positive lug (14) and the negative lug (15).