Cylindrical three-electrode structure and large cylindrical battery

Abstract

The utility model provides a cylindrical three-electrode structure and a large cylindrical battery, the cylindrical three-electrode structure comprises a shell, a battery cell, two connecting assemblies, two end cover assemblies and a reference electrode assembly, the shell is covered with the two end cover assemblies respectively, the battery cell is installed in a containing cavity formed in the shell, the two end cover assemblies are provided with liquid injection holes respectively, and the liquid injection holes are communicated with the shell. The two ends of the battery cell are respectively connected to the two connecting assemblies, and the two connecting assemblies are respectively connected to the corresponding end cover assemblies; the reference electrode assembly comprises a reference wire, a metal lithium sheet, a diaphragm layer and a resin sealing element, the metal lithium sheet is connected to a connecting assembly, one end of the reference wire is wound on the metal lithium sheet and the connecting assembly, the reference wire penetrates through the liquid injection hole, the diaphragm layer covers the metal lithium sheet and the reference wire, and the resin sealing element is mounted in the liquid injection hole. The metal lithium sheet and the connecting assembly are tightly connected by winding the reference lead, so that the test is more accurate; and the diaphragm layer prevents the electrolyte from being in contact with the metal lithium sheet, so that the test stability of the reference electrode is better.

Description

Technical Field

[0001] The present disclosure relates to the technical field of cylindrical batteries, and particularly to a cylindrical three-electrode structure and a large cylindrical battery. Background Art

[0002] With the rapid development of the new energy industry, large cylindrical batteries such as 46120 and 46135 have gradually become the new stars in the industry. Due to their excellent performance and easily flexible size, each manufacturer has invested a lot of funds in them. However, due to the special structure of cylindrical batteries, it is usually difficult to measure the change of electrode potential of the battery during cycling and pulse tests. Traditional three-electrode batteries are mainly designed for soft packs.

[0003] Moreover, one end of the reference electrode is buried inside the battery cell through a copper wire, making the connection position of the reference electrode not firm enough. The reference electrode is directly buried in the accommodation cavity of the battery, making one end of the reference electrode easy to contact with the electrolyte, and the reference electrode is easy to react with the electrolyte, thus affecting the stability of the reference electrode test.

[0004] Another comparative document of the prior art, CN202121757150.9, discloses a reference electrode and a three-electrode battery using the reference electrode, including a lithium foil arranged in the lower section, a metal enameled wire arranged in the upper section, and a metal foil for connecting the lithium foil and the metal enameled wire; wherein, the lithium foil, the metal enameled wire, and the metal foil are all connected by ultrasonic welding. There is also a reference electrode arranged inside an aluminum shell single battery cell. The reference electrode is a special three-section reference electrode, its lower section is a lithium metal foil implanted between the battery cell electrode plates, the upper section is a directly welded metal enameled wire led out from the battery liquid injection hole, and the middle section is a metal foil, which plays a role in connecting the upper section metal enameled wire and the lower section lithium metal wire or lithium metal foil. However, in this solution, the lithium foil in the lower section contacts the electrolyte, and the lithium foil is easy to react with the electrolyte, thus affecting the stability of the reference electrode test. Utility Model Content

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a cylindrical three-electrode structure and a large cylindrical battery with tighter connection and better test stability.

[0006] The purpose of the present disclosure is achieved through the following technical solutions:

[0007] A cylindrical three-electrode structure includes a housing, a battery cell, a first end cap assembly, a second end cap assembly, a connection assembly, and a reference electrode assembly. The housing is provided with an accommodation cavity, the battery cell is installed in the accommodation cavity, the first end cap assembly and the second end cap assembly are respectively covered at both ends of the housing, the first end cap assembly is provided with a first liquid injection hole, and the second end cap assembly is provided with a second liquid injection hole.

[0008] The number of the connection components included is two, and both ends of the battery cell are respectively connected to one end of the two connection components, and the other ends of the two connection components are respectively connected to the first end cover assembly and the second end cover assembly;

[0009] The reference electrode assembly includes a reference wire, a lithium metal sheet, a separator layer, and a resin seal. The lithium metal sheet is connected to one of the connection components. One end of the reference wire is wound around the lithium metal sheet and the connection component. The reference wire passes through the first liquid injection hole. The other end of the reference wire is disposed outside the housing. The separator layer covers the lithium metal sheet and the reference wire, and the resin seal is installed in the first liquid injection hole.

[0010] In one embodiment, the reference wire is wound from one end of the lithium metal sheet and the connection component to the other end of the lithium metal sheet and the connection component.

[0011] In one embodiment, the lithium metal sheet is disposed below the first liquid injection hole.

[0012] In one embodiment, the reference electrode assembly further includes a resin insulating layer. The other end of the reference wire is disposed on the housing, and the resin insulating layer covers the other end of the reference wire.

[0013] In one embodiment, the number of the reference wire, the lithium metal sheet, the separator layer, and the resin seal is two. The two lithium metal sheets are connected to the corresponding connection components. One ends of the two reference wires are respectively wound around the corresponding lithium metal sheets and the connection components. The two separator layers respectively cover the corresponding lithium metal sheets and the reference wires. The other ends of the two reference wires respectively pass through the first liquid injection hole and the second liquid injection hole. The two resin seals are respectively installed in the first liquid injection hole and the second liquid injection hole.

[0014] In one embodiment, each connection component includes a connector and a bus bar. Each lithium metal sheet is connected to the corresponding connector. One ends of the two connectors are respectively connected to the first end cover assembly and the second end cover assembly. The other end of each connector is connected to the corresponding bus bar, and each bus bar is respectively connected to one end of the battery cell.

[0015] In one embodiment, the first end cover assembly includes a first sealing cover, a first spacer, and a first terminal. The first sealing cover covers one end of the housing. The first sealing cover is provided with a first mounting hole and the first liquid injection hole. The first terminal is installed in the first mounting hole, and the first terminal is connected to the corresponding connection component.

[0016] In one embodiment, the second end cap assembly includes a second sealing cap, a second spacer, and a second terminal. The second sealing cap is disposed on the other end of the housing. The second sealing cap is provided with a second mounting hole and a second liquid injection hole. The second terminal is installed in the second mounting hole and is connected to the corresponding connection assembly.

[0017] In one embodiment, the thickness of the separator layer is 15 μm - 17 μm.

[0018] A large cylindrical battery includes the cylindrical three - electrode structure described in any of the above embodiments.

[0019] Compared with the prior art, the present disclosure has at least the following advantages:

[0020] For the above - mentioned cylindrical three - electrode structure and large cylindrical battery, when the resin seal is installed in the first liquid injection hole, the position of the reference wire is fixed, so that the connection of the reference wire is more stable. By winding the reference wire around the lithium metal sheet and the connection assembly, the connection between the reference wire and the lithium metal sheet and the connection assembly is tight, and the change of the electrode potential of the connection assembly tested by the cylindrical three - electrode structure is more accurate. By covering the lithium metal sheet and the connection assembly with the separator layer, the separator layer blocks the contact between the electrolyte and the lithium metal sheet, so that the test stability of the reference electrode is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic structural diagram of a cylindrical three - electrode structure according to an embodiment;

[0023] Figure 2 For Figure 1 It is a schematic structural diagram of the shown reference electrode assembly;

[0024] Figure 3 For Figure 1 It is a partial structural schematic diagram of the shown cylindrical three - electrode structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant accompanying drawings. Preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present disclosure can be understood more thoroughly and comprehensively.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present disclosure belongs. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] To better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure will be further described in detail below with specific embodiments:

[0029] As Figures 1 to 3 shown, a cylindrical three-electrode structure 10 according to an embodiment of the present disclosure includes a housing 100, an electric core 200, a first end cap assembly 300, a second end cap assembly 400, a connection assembly 500, and a reference electrode assembly 600. The housing 100 is provided with a receiving cavity 101. The electric core 200 is installed in the receiving cavity 101. The first end cap assembly 300 and the second end cap assembly 400 are respectively covered on both ends of the housing 100. The first end cap assembly 300 is provided with a first liquid injection hole 301, and the second end cap assembly 400 is provided with a second liquid injection hole 401. The electrolyte can be injected into the receiving cavity 101 through the first liquid injection hole 301 and the second liquid injection hole 401 respectively.

[0030] Furthermore, the number of connection components 500 is two. Both ends of the battery cell 200 are respectively connected to one end of the two connection components 500, and the other ends of the two connection components 500 are respectively connected to the first end cap assembly 300 and the second end cap assembly 400; The reference electrode assembly 600 includes a reference wire 610, a lithium metal sheet 620, a separator layer 630, and a resin seal 640. Using lithium metal for the lithium metal sheet can improve the electrochemical stability of the reference electrode, thereby improving the accuracy of voltage monitoring. The lithium metal sheet 620 is connected to a connection component 500. One end of the reference wire 610 is wound around the lithium metal sheet 620 and the connection component 500. The reference wire 610 passes through the first liquid injection hole 301, and the other end of the reference wire 610 is disposed outside the housing 100. The separator layer 630 covers the lithium metal sheet 620 and the reference wire 610. The resin seal 640 is installed in the first liquid injection hole 301, and epoxy resin is used to seal the first liquid injection hole to form the resin seal 640.

[0031] In this embodiment, first, the two connection components 500 are welded to both ends of the battery cell 200 and then installed in the housing 100. Then, the lithium metal sheet 620 is welded to a connection component 500. One end of the reference wire 610 is wound around the surface of the lithium metal sheet 620. Then, the separator is used to cover the lithium metal sheet 620 and one end of the reference wire 610 wound around the lithium metal sheet 620, so that the part of the reference wire 610 wound around the connection component 500 and the lithium metal sheet 620 are completely covered. Then, the separator is wound and fixed with tape to form the separator layer 630. Then, one end of the reference wire 610 is passed through the first liquid injection hole 301. One connection component 500 is welded to the first end cap assembly 300, and then the first end cap assembly 300 is welded to one end of the housing. The other connection component 500 is welded to the second end cap assembly 400, and then the second end cap assembly 400 is welded to the other end of the housing.

[0032] For the above-mentioned cylindrical three-electrode structure 10, when the resin seal 640 is installed in the first liquid injection hole 301, the position of the reference wire 610 is fixed, so that the connection of the reference wire 610 is more stable. By winding the reference wire 610 around the lithium metal sheet 620 and the connection component 500, the connection between the reference wire 610 and the lithium metal sheet 620 and the connection component 500 is tight, and the change in the electrode potential of the connection component 500 is measured more accurately for the cylindrical three-electrode structure 10; By covering the lithium metal sheet 620 and the connection component 500 with the separator layer 630, the separator layer 630 blocks the contact between the electrolyte and the lithium metal sheet 620, so that the measurement stability of the reference electrode is better.

[0033] As Figure 1 and Figure 2As shown, in one embodiment, the reference wire 610 winds around one end of the lithium metal sheet 620 and the connection component 500 to the other end of the lithium metal sheet 620 and the connection component 500. In this embodiment, by uniformly winding the reference wire 610 around the lithium metal sheet 620 and the connection component 500, the connection between the lithium metal sheet 620 and the connection component 500 is made tighter, thereby increasing the connection strength between the reference wire 610 and the lithium metal sheet 620 and the connection component 500, and enabling the lithium metal sheet 620 and the connection component 500 to be in full contact, so that the reference electrode assembly 600 can accurately measure the change in the electrode potential of the connection component 500.

[0034] As Figure 1 shown, in one embodiment, the lithium metal sheet 620 is disposed below the first liquid injection hole 301. In this embodiment, the lithium metal sheet 620 is disposed below the first liquid injection hole 301, so that the distance between the reference wire 610 and the first liquid injection hole 301 is shorter, reducing the amount of the reference wire 610 used and making the cylindrical three-electrode structure 10 tighter.

[0035] As Figure 2 shown, in one embodiment, the reference electrode assembly 600 further includes a resin insulation layer 650. The other end of the reference wire 610 is disposed outside the housing 100 assembly, and the resin insulation layer 650 covers the other end of the reference wire 610. In this embodiment, the resin insulation layer 650 covers the surface of the reference wire 610, reducing the exposure of the reference wire 610 to the external environment, thereby preventing the external environment from corroding the reference wire 610 and extending the service life of the reference wire 610.

[0036] As Figure 1 shown, in one embodiment, the numbers of the reference wire 610, the lithium metal sheet 620, the separator layer 630, and the resin seal 640 are all two. The two lithium metal sheets 620 are connected to the corresponding connection components 500. One ends of the two reference wires 610 are respectively wound around the corresponding lithium metal sheets 620 and the connection components 500. The two separator layers 630 respectively cover the corresponding lithium metal sheets 620 and the reference wires 610. The other ends of the two reference wires 610 respectively pass through the first liquid injection hole 301 and the second liquid injection hole 401, and the two resin seals 640 are respectively installed in the first liquid injection hole 301 and the second liquid injection hole 401. In this embodiment, through the two reference wires 610, the lithium metal sheets 620, the separator layers 630, and the resin seals 640, the changes in the electrode potentials of the positive and negative electrodes at both ends of the battery cell 200 can be tested simultaneously, so as to quickly measure the change in the electrode potential of the same battery cell 200 and enrich the test data of the battery cell 200.

[0037] As Figure 1 andFigure 3 As shown, in one embodiment, each of the connection components 500 includes a connection member 510 and a current collecting plate 520. Each of the metallic lithium sheets 620 is connected to the corresponding connection member 510. One end of each of the two connection members 510 is respectively connected to the first end cap assembly 300 and the second end cap assembly 400. The other end of each of the connection members 510 is connected to the corresponding current collecting plate 520. Each of the current collecting plates 520 is respectively connected to one end of the battery cell 200. In this embodiment, the battery cell 200 is a battery cell 200 with a non-polar ear structure. The current collecting plate 520 is connected to one end of the battery cell 200, so that the current sequentially passes through the current collecting plate 520 and the connection member 510 evenly, thereby making the change of the electrode potential measured by the metallic lithium sheet 620 more accurate.

[0038] In one embodiment, the thickness of the separator layer 630 is 15 μm - 17 μm. In this embodiment, by using materials such as polypropylene or polyethylene, when the thickness of the separator layer 630 is 15 μm - 17 μm, it has good corrosion resistance, thereby effectively isolating the metallic lithium sheet 620 from contacting the electrolyte.

[0039] As Figure 1 shown, in one embodiment, the first end cap assembly 300 includes a first sealing cover 310 and a first terminal 320. The first sealing cover 310 covers one end of the housing 100. The first sealing cover 310 is provided with a first mounting hole 3101 and a first liquid injection hole 301. The first terminal 320 is installed in the first mounting hole 3101. The first terminal 320 is connected to the corresponding connection component 500. In this embodiment, the first terminal 320 is connected to a connection component 500. The corresponding connection component 500 is provided with a metallic lithium sheet 620 and a reference wire 610. The change of the electrode potential on the first terminal 320 is obtained through the metallic lithium sheet 620 and the reference wire 610.

[0040] As Figure 1As shown, in one of the embodiments, the second end cap assembly 400 includes a second sealing cap 410 and a second pole 420. The second sealing cap 410 covers the other end of the outer shell 100. The second sealing cap 410 is provided with a second mounting hole 4101 and a second liquid injection hole 401. The second pole 420 is installed in the second mounting hole 4101, and the second pole 420 is connected to the corresponding connection assembly 500. In this embodiment, the second pole 420 is connected to another connection assembly 500. The corresponding connection assembly 500 is provided with a lithium metal sheet 620 and a reference wire 610. The change in the electrode potential on the second pole 420 is obtained through the other lithium metal sheet 620 and the reference wire 610. The positions of the lithium metal sheet 620 and the reference wire 610 in the two connection assemblies 500 are the same, so that the test conditions of the first pole 320 and the second pole 420 are the same, and thus the change in the measured electrode potential of the first pole 320 and the second pole 420 is more accurate.

[0041] The present application also provides a large cylindrical battery, including the cylindrical three-electrode structure 10 in any of the above embodiments. In this embodiment, the connection between the reference wire 610 of the reference electrode assembly 600 and the lithium metal sheet 620 and the connection assembly 500 is tight, so that the change in the electrode potential of the large cylindrical battery measured by the reference electrode assembly 600 is more accurate and the test stability is better.

[0042] Compared with the prior art, the present disclosure has at least the following advantages:

[0043] For the above-mentioned cylindrical three-electrode structure 10 and large cylindrical battery, when the resin seal 640 is installed in the first liquid injection hole 301, the position of the reference wire 610 is fixed, so that the connection of the reference wire 610 is more stable. By winding the reference wire 610 around the lithium metal sheet 620 and the connection assembly 500, the connection between the reference wire 610 and the lithium metal sheet 620 and the connection assembly 500 is tight, and the change in the electrode potential of the connection assembly 500 measured by the cylindrical three-electrode structure 10 is more accurate; by covering the lithium metal sheet 620 and the connection assembly 500 with the separator layer 630, the separator layer 630 blocks the contact between the electrolyte and the lithium metal sheet 620, so that the test stability of the reference electrode is better.

[0044] The above-described embodiments only represent several implementation manners of the present disclosure. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the disclosed patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several deformations and improvements can still be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A cylindrical three-electrode structure, comprising a shell, a battery cell, a first end cap assembly, a second end cap assembly, a connecting assembly and a reference electrode assembly, wherein the shell is provided with a receiving cavity, the battery cell is installed in the receiving cavity, the first end cap assembly and the second end cap assembly are respectively provided at both ends of the shell, the first end cap assembly is provided with a first injection hole, the second end cap assembly is provided with a second injection hole, characterized in that: The number of the connecting components is two, the two ends of the battery cell are respectively connected to one end of the two connecting components, and the other ends of the two connecting components are respectively connected to the first end cover component and the second end cover component; The reference electrode assembly includes a reference wire, a metal lithium sheet, a diaphragm layer and a resin seal, the metal lithium sheet is connected to a connecting assembly, one end of the reference wire is wrapped around the metal lithium sheet and the connecting assembly, the reference wire is passed through the first injection hole, the other end of the reference wire is arranged on the outside of the shell, the diaphragm layer is coated on the metal lithium sheet and the reference wire, and the resin seal is installed on the first injection hole.

2. The cylindrical three-electrode structure according to claim 1, characterized in that: The reference wire is wound along the metal lithium sheet and one end of the connecting component to the other end of the metal lithium sheet and the connecting component.

3. The cylindrical three-electrode structure according to claim 1, characterized in that: The metal lithium sheet is arranged below the first injection hole.

4. The cylindrical three-electrode structure according to claim 1, characterized in that: The reference electrode assembly further includes a resin insulating layer. The other end of the reference wire is arranged on the housing. The resin insulating layer covers the other end of the reference wire.

5. The cylindrical three-electrode structure according to claim 1, characterized in that: The number of the reference wires, the metal lithium sheets, the diaphragm layers and the resin seals are all two, the two metal lithium sheets are connected to the corresponding connecting components, one end of the two reference wires are respectively wrapped around the corresponding metal lithium sheets and the connecting components, the two diaphragm layers are respectively covered on the corresponding metal lithium sheets and the reference wires, the other ends of the two reference wires are respectively passed through the first injection hole and the second injection hole, and the two resin seals are respectively installed on the first injection hole and the second injection hole.

6. The cylindrical three-electrode structure according to claim 5, characterized in that: Each of the connecting components includes a connecting piece and a busbar, each of the metal lithium sheets is connected to the corresponding connecting piece, one end of the two connecting pieces is respectively connected to the first end cover assembly and the second end cover assembly, the other end of each of the connecting pieces is connected to the corresponding busbar, and each of the busbars is respectively connected to one end of the battery cell.

7. The cylindrical three-electrode structure according to claim 5, characterized in that: The first end cover assembly includes a first sealing cover, a first isolation sheet and a first pole. The first sealing cover is disposed on one end of the shell. The first sealing cover is provided with a first mounting hole. The first sealing cover is provided with the first liquid injection hole. The first pole is installed in the first mounting hole. The first pole is connected to the corresponding connecting assembly.

8. The cylindrical three-electrode structure according to claim 7, characterized in that: The second end cover assembly includes a second sealing cover, a second isolation sheet and a second pole. The second sealing cover is disposed on the other end of the housing. The second sealing cover is provided with a second mounting hole. The second sealing cover is provided with a second liquid injection hole. The second pole is installed in the second mounting hole. The second pole is connected to the corresponding connecting assembly.

9. The cylindrical three-electrode structure according to claim 1, characterized in that: The thickness of the diaphragm layer is 15 μm-17 μm.

10. A large cylindrical battery, characterized in that: A cylindrical three-electrode structure comprising any one of claims 1 to 9.

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