Three-electrode battery

Abstract

The utility model discloses a three-electrode battery, which comprises a shell assembly, a battery cell and a sealant, the battery cell is arranged in the shell assembly, the battery cell comprises a positive electrode, a negative electrode and a reference electrode which are mutually insulated, one end of the reference electrode is arranged in a through hole in a penetrating manner, and the sealant comprises a first sealing part, a connecting part and a second sealing part, the first sealing part is connected with the second sealing part through the connecting part, the reference electrode is sleeved with the connecting part, the first sealing part is attached to the periphery of the side, facing the battery cell, of the through hole, and the second sealing part is attached to the periphery of the side, deviating from the battery cell, of the through hole. The two opposite sides of the through hole can be sealed at the same time, so that the connection strength of the sealant and the shell assembly is improved, and the sealing performance of the three-electrode battery can be improved.

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 are mainly composed of positive electrodes, negative electrodes, diaphragms and electrolytes. In actual use, the voltage measured in the circuit is the voltage difference between the positive and negative electrodes, which reflects the overall performance of the battery. As the charging current increases, the polarization of the positive and negative electrodes of the battery increases simultaneously, and the potential of the negative electrode approaches or even falls below 0V, which may lead to the possibility of surface lithium precipitation. On the one hand, it leads to reversible lithium loss in the battery, and on the other hand, the precipitated metallic lithium easily causes safety problems such as short circuits in the battery. Therefore, in order to study the electrochemical characteristics of the positive and negative electrodes of the battery, a third electrode, namely the reference electrode, is introduced. By monitoring and analyzing the potential changes of the positive and negative electrodes relative to the third electrode, the working status of the positive and negative electrodes inside the battery can be effectively analyzed.

[0003] In the prior art, the reference electrode of a three-electrode battery is generally led out from a through hole on the shell. After the reference electrode is led out, the battery needs to be sealed. Traditional three-electrode batteries generally apply sealant on the outside of the through hole to seal the three-electrode battery. In actual use, the reference electrode is often pulled, making the sealant easy to fall off, resulting in poor sealing performance of the three-electrode cylindrical electrode. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a three-electrode battery, which can provide the sealing performance of the three-electrode battery.

[0005] According to the three-electrode battery of the embodiment of the utility model, it includes a shell assembly, a battery cell and a sealant, the shell assembly is provided with an inner cavity, the inner cavity has a through hole, the battery cell is arranged in the shell assembly, the battery cell includes a positive electrode, a negative electrode and a reference electrode, the positive electrode, the negative electrode and the reference electrode are insulated from each other, one end of the reference electrode is passed through the through hole, the sealant includes a first sealing part, a connecting part and a second sealing part, the first sealing part is connected to the second sealing part through the connecting part, the connecting part is sleeved on the reference electrode, the first sealing part is in contact with the periphery of the through hole on the side facing the battery cell, and the second sealing part is in contact with the periphery of the through hole on the side facing away from the battery cell.

[0006] The three-electrode battery according to the embodiment of the utility model has at least the following beneficial effects:

[0007] By providing the first sealing portion and the second sealing portion, the two opposite sides of the through hole can be sealed simultaneously, so as to improve the connection strength between the sealant and the shell assembly, and the sealing performance of the three-electrode battery can be improved.

[0008] According to some embodiments of the present utility model, the thickness of the first sealing portion is greater than the thickness of the second sealing portion.

[0009] According to some embodiments of the present utility model, the width of the first sealing portion is greater than the width of the second sealing portion.

[0010] According to some embodiments of the present utility model, the sealant is configured as a hot melt adhesive.

[0011] According to some embodiments of the present utility model, the housing assembly includes a housing body, a first end cap, and a second end cap. The two ends of the housing body have openings. The first end cap covers the opening at one end of the housing body, and the second end cap covers the opening at the other end of the housing body. The positive electrode is connected to the first end cap, the negative electrode is connected to the second end cap, and the through hole is provided in the second end cap.

[0012] According to some embodiments of the present utility model, the battery cell further includes a first separator, a second separator, and a third separator. The first separator, the negative electrode, the second separator, the third separator, and the positive electrode are stacked and wound. The other end of the reference electrode is disposed between the second separator and the third separator.

[0013] According to some embodiments of the present utility model, an insulating component is further included. The insulating component is disposed between the reference electrode and the sealant, and one end of the insulating component is located between the second separator and the third separator.

[0014] According to some embodiments of the present utility model, the insulating component includes a first insulating member and a second insulating member connected to the first insulating member. The first insulating member and the second insulating member enclose an insulating channel, and the reference electrode passes through the insulating channel.

[0015] According to some embodiments of the present utility model, the first insulating member is bonded to the second insulating member.

[0016] According to some embodiments of the present utility model, the insulating component is connected to the second separator, and / or the insulating component is connected to the third separator.

[0017] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present utility model will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0019] Figure 1 Schematic diagram of the internal structure of a three - electrode battery according to an embodiment of the present utility model;

[0020] Figure 2 is Figure 1 partial enlarged view of part A in

[0021] Figure 3 Assembly schematic diagram of the reference electrode, insulation component and sealant before the sealant of the embodiment of the present utility model is melted

[0022] Figure 4 is Figure 3 top view of

[0023] Reference numerals:

[0024] Inner cavity 101, through - hole 102, housing body 110, first end - cover 120, second end - cover 130, positive electrode 210, negative electrode 220, reference electrode 230, first separator 240, second separator 250, third separator 260, sealant 300, first sealing part 310, connecting part 320, second sealing part 330, insulation component 400, first insulating part 410, second insulating part 420. Detailed implementation manners

[0025] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation of the present utility model.

[0026] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model 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, and thus should not be construed as a limitation of the present utility model.

[0027] In the description of the present utility model, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0028] In the description of the present utility model, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0029] Referring to Figure 1 、 Figure 2 According to an embodiment of the present utility model, a three - electrode battery includes a housing assembly, an electric core, and a sealant 300. The electric core is disposed within the housing assembly. The electric core includes a positive electrode 210, a negative electrode 220, and a reference electrode 230 that are insulated from each other. One end of the reference electrode 230 passes through a through - hole 102. The sealant 300 includes a first seal portion 310, a connecting portion 320, and a second seal portion 330. The first seal portion 310 is connected to the second seal portion 330 through the connecting portion 320. The connecting portion 320 is sleeved on the reference electrode 230. The first seal portion 310 is attached to the periphery of the side of the through - hole 102 facing the electric core, and the second seal portion 330 is attached to the periphery of the side of the through - hole 102 facing away from the electric core. Thus, by providing the first seal portion 310 and the second seal portion 330, the opposite sides of the through - hole 102 can be sealed simultaneously, so as to improve the connection strength between the sealant 300 and the housing assembly, and improve the sealing performance of the three - electrode battery.

[0030] Specifically, the first seal portion 310 is attached to the periphery of the side of the through - hole 102 facing the electric core, and the second seal portion 330 is attached to the periphery of the side of the through - hole 102 facing away from the electric core. When one end of the reference electrode 230 has a tendency to move in the direction of extending out of the housing assembly, the first seal portion 310 abuts against the periphery of the side of the through - hole 102 facing the electric core to limit the separation of the second seal portion 330 from the housing assembly. When one end of the reference electrode 230 has a tendency to move in the direction of retracting into the housing assembly, the second seal portion 330 abuts against the periphery of the side of the through - hole 102 facing away from the electric core to limit the separation of the first seal portion 310 from the housing assembly, which can improve the connection strength between the sealant 300 and the housing assembly and improve the sealing performance of the three - electrode battery.

[0031] It should be noted that the reference electrode 230 is one of a metal copper wire, a lithium - plated copper wire, a copper foil, and a lithium foil, which will not be elaborated here.

[0032] To facilitate the sealing of the through-hole 102, the sealant 300 is selected to be a hot-melt adhesive material. The hot-melt adhesive is a plastic adhesive, and within a certain temperature range, its physical state changes with the temperature while its chemical properties remain unchanged. Before installing the sealant 300, the sealant 300 is sleeved on the reference electrode 230. Before installing the sealant 300, one end of the reference electrode 230 extends out of the through-hole 102 from the inside of the housing assembly. Under the action of an external force, the length of the reference electrode 230 extending out of the housing assembly increases until a part of the sealant 300 is accommodated in the through-hole 102. Then, stop pulling the reference electrode 230 and use a heating tool (such as a soldering iron tip) to heat the housing assembly. In this way, the inside and outside of the hot-melt adhesive can be melted. The melted inside of the hot-melt adhesive forms the first sealing portion 310, and the melted outside of the hot-melt adhesive forms the second sealing portion 330, which can improve the connection strength between the sealant 300 and the housing assembly and can improve the sealing performance of the three-electrode battery.

[0033] It should be noted that the inside of the hot-melt adhesive refers to the part of the hot-melt adhesive located inside the housing assembly, and the outside of the hot-melt adhesive refers to the part of the hot-melt adhesive located outside the housing assembly.

[0034] Referring to Figure 3 , Figure 4 , to facilitate guiding the hot-melt adhesive to extend outside the housing assembly, the hot-melt adhesive has a conical structure before being melted. When installing the sealant 300, the tip of the conical structure faces the through-hole 102. When moving the reference electrode 230, the tip of the conical structure extends outside the housing assembly, which can automatically correct the relative position between the sealant 300 and the through-hole 102 to facilitate the assembly of the sealant 300.

[0035] It should be pointed out that when the hot-melt adhesive has a conical structure before being melted, the volume of the inside of the hot-melt adhesive is larger than the volume of the outside of the hot-melt adhesive. After the hot-melt adhesive is melted, the thickness of the first sealing portion 310 is greater than the thickness of the second sealing portion 330, the width of the first sealing portion 310 is greater than the width of the second sealing portion 330, and the width of the second sealing portion 330 is greater than the diameter of the through-hole 102, which can improve the sealing performance of the three-electrode battery.

[0036] It should be pointed out that the thickness of the first sealing portion 310 refers to the dimension of the first sealing portion 310 in the axial direction of the housing assembly, and the width of the first sealing portion 310 refers to the dimension of the first sealing portion 310 in the direction perpendicular to the axial direction of the housing assembly. Similarly, the thickness of the second sealing portion 330 refers to the dimension of the second sealing portion 330 in the axial direction of the housing assembly, and the width of the second sealing portion 330 refers to the dimension of the second sealing portion 330 in the direction perpendicular to the axial direction of the housing assembly, which will not be elaborated here.

[0037] As another implementation manner, the hot-melt adhesive can also have a frustum structure or a truncated pyramid structure before being melted, which will not be elaborated here.

[0038] It can be understood that the heating tool can indirectly heat the sealant 300 through the housing assembly or directly heat the sealant 300, which will not be elaborated here.

[0039] In some embodiments of the present invention, when the battery cell is configured as a wound battery cell, the battery cell further includes a first separator 240, a second separator 250, and a third separator 260. The first separator 240, the negative electrode 220, the second separator 250, the third separator 260, and the positive electrode 210 are stacked in sequence to form a battery cell unit, and the battery cell unit is wound to form a battery cell. One end of the reference electrode 230 is disposed between the second separator 250 and the third separator 260, so that the positive electrode 210, the negative electrode 220, and the reference electrode 230 can be insulated from each other, thereby providing the use reliability of the three-electrode battery.

[0040] It should be noted that before winding the battery cell unit, one end of the reference electrode 230 is pretreated by inserting it into concentrated sulfuric acid and soaking for about twenty minutes to remove the surface oxide layer and the surface protective layer, so that one end of the reference electrode 230 is in a bare state. In the following description, one end of the reference electrode 230 in a bare state is simply referred to as the bare end of the reference electrode 230. Subsequently, it is baked in a vacuum environment at 80 °C for two hours to dry the bare end of the reference electrode 230 and prevent the bare end of the reference electrode 230 from being oxidized.

[0041] In the three-electrode battery according to the embodiment of the present invention, after the drying process of the bare end of the reference electrode 230 is completed, an insulating assembly 400 is sleeved on the middle part of the reference electrode 230. Then, hot melt adhesive is cast in the insulating assembly 400 through a mold, which can facilitate the fixing of the relative positions of the sealant 300 and the reference electrode 230. After the winding process of the battery cell unit is completed, the battery cell is disassembled without unwinding, so that the bare end of the reference electrode 230 is inserted between the second separator 250 and the third separator 260 to separate the reference electrode 230 from the positive electrode 210 and the negative electrode 220 respectively, so as to prevent the reference electrode 230 from being short-circuited with the positive electrode 210 or the negative electrode 220.

[0042] To facilitate the extraction of the reference electrode 230, the second end cap 130 covers the opening at one end of the housing body 110, and a through hole 102 is provided on the second end cap 130, so that the reference electrode 230 can be inserted between the second diaphragm 250 and the third diaphragm 260 along the axial direction of the housing body 110. When the battery cell is installed in the housing body 110, the end of the reference electrode 230 far from the negative electrode 220 can be aligned with the through hole 102 first, and then the entire battery cell is installed in the housing body 110. The reference electrode 230 gradually extends out of the through hole 102 as the battery cell moves, without the need to additionally calibrate the relative position of the reference electrode 230 and the through hole 102, which facilitates the extraction of the reference electrode 230. As another implementation manner, the through hole 102 can also be provided on the first end cap 120 or the housing body 110, which will not be elaborated here. It should be noted that the cross-section of the housing body 110 perpendicular to its axial direction is one of a circular structure or a rectangular structure, which will not be elaborated here.

[0043] As another implementation manner, when the battery cell is configured as a stacked battery cell, the battery cell includes a first battery cell unit and a plurality of second battery cell units stacked. The first battery cell unit further includes a fourth diaphragm, a fifth diaphragm, and a sixth diaphragm. The fourth diaphragm, the negative electrode 220, the fifth diaphragm, the sixth diaphragm, and the positive electrode 210 are stacked to form the first battery cell unit. The exposed end of the reference electrode 230 is inserted between the fifth diaphragm and the sixth diaphragm. The second battery cell unit further includes a seventh diaphragm and an eighth diaphragm. The seventh diaphragm, the negative electrode 220, the eighth diaphragm, and the positive electrode 210 are stacked in sequence to form the second battery cell unit.

[0044] In the insulating component 400 of the embodiment of the present invention, the insulating component 400 is wrapped around the middle of the reference electrode 230. The insulating component 400 passes through the through hole 102, and one end of the insulating component 400 is disposed between the second diaphragm 250 and the third diaphragm 260, and the other end of the insulating component 400 extends out of the through hole 102. Through the insulating component 400, the reference electrode 230 can be insulated from the housing component, and the reference electrode 230 can be protected, which can improve the use reliability of the three-electrode battery.

[0045] To facilitate the assembly of the insulating component 400, the insulating component 400 includes a first insulating member 410 and a second insulating member 420 connected to the first insulating member 410. Both the first insulating member 410 and the second insulating member 420 are configured as adhesive tapes with insulating properties. When assembling the first insulating member 410 and the second insulating member 420, the first insulating member 410 and the second insulating member 420 are pasted face to face, and the first insulating member 410 and the second insulating member 420 enclose an insulating channel. The reference electrode 230 passes through the insulating channel, and the opposite sides of the reference electrode 230 are also adhesively fixed to the first insulating member 410 and the second insulating member 420 respectively, which facilitates the assembly of the insulating component 400.

[0046] As another implementation, the first insulating member 410 and the second insulating member 420 can also be fixed on the reference electrode 230 by winding, and the first insulating member 410 and the second insulating member 420 can also be formed on the reference electrode 230 by molding. Details are not described herein.

[0047] To improve the connection stability of the insulating assembly 400, one end of the insulating assembly 400 can also be fixedly connected to the second separator 250 by tape, which can limit the movement of the insulating assembly 400 along the length direction of the reference electrode 230 to prevent the reference electrode 230 from detaching from the insulating assembly 400. In addition, one end of the insulating assembly 400 can also be directly bonded to the second separator 250, which can also improve the connection stability of the insulating assembly 400.

[0048] As another implementation, one end of the insulating assembly 400 can also be fixedly connected to the third separator 260 by tape, or one end of the insulating assembly 400 can be directly bonded to the third separator 260. Details are not described herein.

[0049] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0050] The above has described this embodiment in detail with reference to the drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist within the knowledge scope of those of ordinary skill in the art.

Claims

1. A three - electrode battery, characterized in that, include: A housing assembly is provided with an inner cavity (101), wherein the inner cavity (101) has a through hole (102); A battery cell is disposed in the housing assembly, the battery cell comprising a positive electrode (210), a negative electrode (220) and a reference electrode (230), the positive electrode (210), the negative electrode (220) and the reference electrode (230) being insulated from each other, and one end of the reference electrode (230) is passed through the through hole (102); The sealant (300) comprises a first sealing portion (310), a connecting portion (320) and a second sealing portion (330), wherein the first sealing portion (310) is connected to the second sealing portion (330) via the connecting portion (320), the connecting portion (320) is sleeved on the reference electrode (230), the first sealing portion (310) is in contact with the periphery of the through hole (102) on the side facing the battery cell, and the second sealing portion (330) is in contact with the periphery of the through hole (102) on the side facing away from the battery cell.

2. The three-electrode battery according to claim 1, characterized in that, The thickness of the first sealing portion (310) is greater than the thickness of the second sealing portion (330).

3. The three-electrode battery according to claim 1, wherein The width of the first sealing portion (310) is greater than the width of the second sealing portion (330).

4. The three-electrode battery according to claim 1, wherein, The sealant (300) is configured as hot melt adhesive.

5. The three-electrode battery according to claim 1, characterized in that, The shell assembly includes a shell body (110), a first end cover (120) and a second end cover (130), the shell body (110) has openings at both ends, the first end cover (120) is covered on the opening at one end of the shell body (110), and the second end cover (130) is covered on the opening at the other end of the shell body (110), the positive electrode (210) is connected to the first end cover (120), the negative electrode (220) is connected to the second end cover (130), and the through hole (102) is provided on the second end cover (130).

6. The three-electrode battery according to claim 1, characterized in that, The battery cell further comprises a first separator (240), a second separator (250) and a third separator (260); the first separator (240), the negative electrode (220), the second separator (250), the third separator (260) and the positive electrode (210) are stacked and wound; the other end of the reference electrode (230) is arranged between the second separator (250) and the third separator (260).

7. The three-electrode battery according to claim 6, characterized in that, It also includes an insulating component (400), wherein the insulating component (400) is disposed between the reference electrode (230) and the sealant (300), and one end of the insulating component (400) is located between the second diaphragm and the third diaphragm.

8. The three-electrode battery according to claim 7, characterized in that, The insulating component (400) comprises a first insulating member (410) and a second insulating member (420) connected to the first insulating member (410), the first insulating member (410) and the second insulating member (420) enclose an insulating channel, and the reference electrode (230) is disposed in the insulating channel.

9. The three - electrode battery according to claim 8, characterized in that, The first insulating member (410) is bonded to the second insulating member (420).

10. The three-electrode battery according to claim 7, characterized in that, The insulation component (400) is connected to the second diaphragm (250), and / or the insulation component (400) is connected to the third diaphragm (260).

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