Reference electrode and battery thereof

Abstract

The reference electrode comprises at least one metal wire and an insulating adhesive layer, the metal wire comprises a first part and a second part, the first part comprises a bare metal wire and an insulating layer wrapping the outer surface of the bare metal wire, and the second part is the bare metal wire; the insulating adhesive layer extends along the first direction, and the first parts of all the metal wires are wrapped in the insulating adhesive layer. The first part of the metal wire is coated with the insulating glue layer, so that the tensile strength of the metal wire coated with the insulating glue layer is far higher than that of a single metal wire, the external reference electrode metal wire is not easy to pull apart in the battery manufacturing process, and the quality of the reference electrode is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a reference electrode and a battery thereof. Background Art

[0002] With the improvement of performance and production level, lithium-ion batteries have begun to be used in green and environmentally friendly new energy electric vehicles and other electric vehicles, becoming a very important product in the new energy industry. In response to the needs of the development of lithium-ion batteries, the research on lithium-ion batteries has also become more in-depth. Among them, the production of three-electrode batteries can be used to detect the electrochemical properties of lithium-ion batteries, such as lithium precipitation potential, cathode and anode charging and discharging, high and low temperature performance, etc. The three-electrode method of monitoring lithium-ion batteries has become the most important means of pre-research, failure analysis, and electrochemical reaction behavior monitoring of battery cells, and is favored by domestic and foreign R&D personnel.

[0003] In the related art, the reference electrode of a three-electrode battery is usually made of enameled copper wire that is implanted into the battery to produce the three-electrode battery. However, due to the pulling of the robot on the production line, the implanted copper wire is likely to be torn off by the robot, resulting in a high failure rate of the three-electrode batteries prepared on the production line.

[0004] At the same time, when installing the reference electrode, it is also very important to ensure the sealing of the connection between the reference electrode and the battery housing. Utility Model Content

[0005] The purpose of the utility model is to provide a reference electrode and a battery thereof to solve the technical problem of poor quality of the reference electrode in the prior art. The preferred technical solution among the many technical solutions provided by the utility model can produce many technical effects as described below.

[0006] The technical solution adopted in this application is:

[0007] In a first aspect, the present application provides a reference electrode, comprising:

[0008] at least one metal wire, the metal wire comprising a first portion and a second portion, the first portion comprising a bare metal wire and an insulating layer wrapped around an outer surface of the bare metal wire, and the second portion being the bare metal wire;

[0009] The insulating adhesive layer is extended along a first direction and covers the first part of all metal wires in the insulating adhesive layer.

[0010] In some embodiments of the present application, the insulating adhesive layer includes a first insulating adhesive layer and a second insulating adhesive layer, wherein the first insulating adhesive layer and the second insulating adhesive layer are arranged opposite to each other, and the first part of all metal wires is coated between the first insulating adhesive layer and the second insulating adhesive layer.

[0011] In some embodiments of the present application, a first insulating adhesive layer is adhered to one side surface of the first portion of all metal wires along a first direction, and a second insulating adhesive layer is adhered to the first insulating adhesive layer on the other side surface opposite to all metal wires.

[0012] In some embodiments of the present application, the first insulating adhesive layer and the second insulating adhesive layer are both fiber adhesive tapes, and a pressure-sensitive adhesive is coated on the side of the fiber adhesive tape facing the metal wire;

[0013] The fiber tape contains fiber structures arranged at intervals, the extending direction of the fiber structures is consistent with the extending direction of the metal wires, and the diameter of each fiber structure is 5 to 30 microns.

[0014] In some embodiments of the present application, the diameter of the metal wire is 22-50 micrometers, and the length of the second portion of the metal wire is 3-5 cm.

[0015] In some embodiments of the present application, the thickness of the first insulating adhesive layer or the second insulating adhesive layer is 20-70 μm.

[0016] In some embodiments of the present application, when the metal wires include at least two, all the metal wires are arranged side by side, and the interval d between two adjacent metal wires satisfies: 0<d<1mm.

[0017] In a second aspect, the present application also provides a battery, comprising:

[0018] An electrode assembly, comprising a negative electrode sheet, a positive electrode sheet and the reference electrode, wherein the second portion of the reference electrode and the first portion of the portion wrapped with the insulating adhesive layer are arranged between the positive electrode sheet and the negative electrode sheet;

[0019] a housing having a cavity for accommodating the electrode assembly;

[0020] A top cover is connected to the shell, and a reference electrode is sealed and connected to the top cover.

[0021] In some embodiments of the present application, a mounting hole is provided on the top cover, a first mounting groove is provided on the side of the mounting hole facing away from the cavity, a mounting member is fixed on the first mounting groove, a second mounting groove is provided on the side of the mounting member facing away from the cavity, a first sealing member is provided on the side facing the cavity, the first sealing member is provided with a through hole connected to the cavity, the aperture of the through hole gradually decreases from the outside to the inside of the battery, and the first part wrapped with the insulating rubber layer is interference fit connected with the maximum aperture of the through hole, the reference electrode is inserted into the through hole and a second sealing member is fixed on the second mounting groove.

[0022] In some embodiments of the present application, the electrode assembly further includes:

[0023] A first diaphragm is provided on a side of the negative electrode sheet facing the positive electrode sheet, and the second portion of the reference electrode and the first portion of the portion wrapped with the insulating rubber layer are implanted between the first diaphragm and the positive electrode sheet;

[0024] The second diaphragm is arranged between the reference electrode and the positive electrode sheet.

[0025] Based on the above technical solution, the reference electrode and the battery provided by the present application have the following beneficial effects:

[0026] The reference electrode provided in the embodiment of the present application includes at least one metal wire and an insulating adhesive layer, wherein the metal wire includes a first part and a second part, wherein the first part includes a bare metal wire and an insulating layer wrapped around the outer surface of the bare metal wire, and the second part is a bare metal wire; the insulating adhesive layer is extended along a first direction, and the first part of all the metal wires is coated in the insulating adhesive layer. By coating the insulating adhesive layer on the first part of the metal wire, the tensile strength of the metal wire coated with the insulating adhesive layer is much greater than that of a single metal wire, at least several dozen times that of a single metal wire, and during the battery manufacturing process, it is not easy for the external reference electrode metal wire to be torn off, thereby improving the quality of the reference electrode.

[0027] On the other hand, the battery provided by the embodiment of the present application includes: an electrode assembly, a shell and a top cover, the electrode assembly includes a negative electrode sheet, a positive electrode sheet and the reference electrode, the second part of the reference electrode and the first part wrapped with an insulating rubber layer are arranged between the positive electrode sheet and the negative electrode sheet; the shell has a cavity for accommodating the electrode assembly; the top cover is connected to the shell, and the reference electrode is sealed and connected to the top cover. A mounting hole and a mounting member are provided on the top cover, and a first sealing member is provided on the mounting member. The first sealing member is provided with a through hole connected to the cavity, the aperture of the through hole gradually decreases from the outside to the inside of the battery, and the first part wrapped with an insulating rubber layer is connected with the maximum aperture of the through hole by interference fit, the reference electrode is inserted into the through hole and a second sealing member is fixed on the second mounting groove, thereby realizing the sealed connection of the reference electrode on the top cover, and improving the sealing of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 A schematic diagram of the structure of a reference electrode according to one or more embodiments of the present application;

[0030] Figure 2 A perspective structural diagram of a battery according to one or more embodiments of the present application;

[0031] Figure 3 A schematic diagram of a three-dimensional structure of a battery according to one or more embodiments of the present application;

[0032] Figure 4 A schematic diagram of a top view of a battery according to one or more embodiments of the present application;

[0033] Figure 5 An exploded view of a top cover of a battery according to one or more embodiments of the present application;

[0034] Figure 6 A schematic diagram of a mounting member from a bottom perspective of one or more embodiments of the present application;

[0035] Figure 7 A schematic diagram of the structure of an electrode assembly according to one or more embodiments of the present application;

[0036] Figure 8 A diagram showing the installation method of a reference electrode in an electrode assembly according to one or more embodiments of the present application.

[0037] In the figure: 10-metal wire; 11-first part; 12-second part; 110-bare metal wire; 111-insulating layer; 20-insulating rubber layer; 21-first insulating rubber layer; 22-second insulating rubber layer; 23-fiber structure; 30-shell; 31-top cover; 32-electrode assembly; 33-mounting piece; 34-second sealing piece; 35-reference electrode; 311-mounting hole; 312-first mounting groove; 321-negative electrode sheet; 322-first diaphragm; 323-second diaphragm; 324-positive electrode sheet; 325-second fixing tape; 330-second mounting groove; 331-first sealing piece; 332-through hole. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0040] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the related art, when making a reference electrode on the shell, the implanted metal wire or metal wire is very likely to be torn off by the robot on the production line. Therefore, the failure rate is very high when preparing a three-electrode battery.

[0043] Based on the above considerations, in order to solve the technical problem of poor quality of the reference electrode, the present application provides a reference electrode, the reference electrode includes at least one metal wire and an insulating adhesive layer, the metal wire includes a first part and a second part, the first part includes a bare metal wire and an insulating layer wrapped around the outer surface of the bare metal wire, and the second part is a bare metal wire; the insulating adhesive layer is extended along a first direction, and the first part of all metal wires is coated in the insulating adhesive layer. By coating the insulating adhesive layer on the first part of the metal wire, the tensile strength of the metal wire coated with the insulating adhesive layer is much greater than that of a single metal wire, at least several dozen times that of a single metal wire. In the battery manufacturing process, it is not easy to tear the external reference electrode metal wire, thereby improving the quality of the reference electrode and the success rate of manufacturing a three-electrode battery.

[0044] The reference electrode of the embodiment of the present application can be applicable to lithium-ion three-electrode batteries, other three-electrode batteries or other electrochemical systems using a reference electrode.

[0045] The technical solution of the present application is described in detail below in conjunction with the accompanying drawings.

[0046] Please refer to Figure 1A reference electrode provided in an embodiment of the present application includes: at least one metal wire 10 and an insulating adhesive layer 20, the metal wire 10 includes a first part 11 and a second part 12, the first part 11 includes a bare metal wire 110 and an insulating layer 111 wrapped around the outer surface of the bare metal wire, and the second part 12 is the bare metal wire 110; the insulating adhesive layer 20 extends along a first direction and covers the first part 11 of all the metal wires 10 in the insulating adhesive layer 20.

[0047] The first direction may be a length direction of the metal wire 10. The first portion 11 and the second portion 12 of the metal wire 10 are adjacently arranged along the length direction of the metal wire 10, that is, the first portion 11 and the second portion 12 have a connection.

[0048] In the technical solution of the embodiment of the present application, by coating the insulating adhesive layer 20 on the first part 11 of the metal wire 10, the tensile strength of the metal wire 10 coated with the insulating adhesive layer 20 is much greater than that of a single metal wire, about several dozen times greater than that of a single metal wire. During the battery manufacturing process, the external reference electrode metal wire is not easily torn off, thereby improving the quality of the reference electrode.

[0049] In some embodiments, please refer to Figure 1 The insulating rubber layer 20 includes a first insulating rubber layer 21 and a second insulating rubber layer 22 , wherein the first insulating rubber layer 21 and the second insulating rubber layer 22 are arranged opposite to each other, and the first part 11 of all the metal wires 10 is coated between the first insulating rubber layer 21 and the second insulating rubber layer 22 .

[0050] The first insulating adhesive layer 21 and the second insulating adhesive layer 22 may be arranged opposite to each other by having adhesive surfaces of the first insulating adhesive layer 21 and the second insulating adhesive layer 22 arranged opposite to each other.

[0051] In the technical solution of the embodiment of the present application, by setting the insulating rubber layer 20 as the first insulating rubber layer 21 and the second insulating rubber layer 22, and the first insulating rubber layer 21 and the second insulating rubber layer 22 are arranged relatively to cover all the metal wires 10, the structure is simple and the preparation process is easy to operate.

[0052] In some embodiments, the first insulating adhesive layer 21 is adhered to one side surface of the first portion 11 of all metal wires 10 along a first direction, and the second insulating adhesive layer 22 is adhered to the first insulating adhesive layer 21 on the other side surface opposite to all metal wires 10 .

[0053] In the technical solution of the embodiment of the present application, the first insulating adhesive layer 21 is adhered to one side surface of the first part 11 of all the metal wires 10, and the second insulating adhesive layer 22 is adhered to the first insulating adhesive layer 21 on the other side surface opposite to all the metal wires 10, so that all the metal wires 10 are wrapped side by side between the first insulating adhesive layer 21 and the second insulating adhesive layer 22. The preparation process is convenient to operate. At the same time, when the metal wires 10 include multiple wires, the distance between two adjacent metal wires 10 can be effectively maintained to avoid short circuit.

[0054] In some embodiments, please refer to Figure 1 The first insulating adhesive layer 21 and the second insulating adhesive layer 22 are both fiber tapes, and a pressure-sensitive adhesive is coated on the side of the fiber tape facing the metal wire 10; the fiber tape contains spaced fiber structures 23, and the extension direction of the fiber structure 23 is consistent with the extension direction of the metal wire 10, and the diameter of each fiber structure is 5 to 30 microns.

[0055] The fiber tape can be a product with PET, polyolefin, polyurethane or polypropylene as the base material, and the fiber structure 23 can be a polyester fiber line. The fiber tape contains polyester fiber lines, and the diameter of the polyester fiber lines is 5 to 30 microns.

[0056] In the technical solution of the embodiment of the present application, both the first insulating adhesive layer 21 and the second insulating adhesive layer 22 are made of fiber tape, and a pressure-sensitive adhesive is coated on the side of the fiber tape facing the metal wire 10, so that the first insulating adhesive layer 21 and the second insulating adhesive layer 22 are relatively adhered to each other and all the metal wires 10 are covered. The fiber tape has a high fracture resistance and is not easy to break. The pressure-sensitive adhesive layer can have a long-lasting adhesive force, ensuring good adhesion and performance.

[0057] In some embodiments, the diameter of the metal wire 10 is 22 to 50 micrometers. The length of the second portion 12 of the metal wire 10 is 3 to 5 cm.

[0058] The diameter of the metal wire 10 may be the diameter of the first portion 11 of the metal wire 10 .

[0059] In some embodiments, the length of the insulating adhesive layer 20 along the first direction may be 10-17 cm. The length of the insulating adhesive layer 10 may be adjusted as the length of the second portion 12 changes.

[0060] In the technical solution of the embodiment of the present application, by setting the length of the second portion 12 of the metal wire 10 to 3-5 cm, the bare metal wire 110 of the second portion 12 is implanted in the battery for conduction.

[0061] In some embodiments, the thickness of the first insulating adhesive layer 21 or the second insulating adhesive layer 22 is 20-70 μm.

[0062] In the technical solution of the embodiment of the present application, through the above-mentioned configuration, the insulating adhesive layer 20 has good fracture resistance and is not easy to break.

[0063] In some embodiments, when the metal wires 10 include at least two, all the metal wires 10 are arranged side by side, and the distance d between two adjacent metal wires 10 satisfies: 0<d<1 mm.

[0064] Arranging all metal wires 10 side by side may mean that all metal wires 10 do not cross each other.

[0065] In the technical solution of the embodiment of the present application, through the above settings, all metal wires 10 are arranged side by side, and the distance d between two adjacent metal wires 10 satisfies: 0<d<1mm, so that there is no crossing between two adjacent metal wires 10 to avoid short circuit.

[0066] In some embodiments, the metal wire 10 may be a copper wire.

[0067] On the other hand, the present invention also provides a method for preparing a reference electrode, comprising:

[0068] Provide at least one metal wire 10, the metal wire 10 includes a first part 11 and a second part 12, the first part 11 includes a bare metal wire 110 and an insulating layer 111 wrapped around the outer surface of the bare metal wire, and the second part 12 is the bare metal wire;

[0069] An insulating adhesive layer 20 is provided and is extended from one end portion of all metal wires 10 to the other end portion along a first direction, and the first portions 11 of all metal wires 10 are covered in the insulating adhesive layer 20 .

[0070] In some embodiments of the present application, a method for preparing a reference electrode comprises:

[0071] 1. Provide a metal wire 10 such as a copper wire, and wind the metal wire 10 on a support to form two layers of metal wire 10 on both sides of the support. The support may be an acrylic or glass plate.

[0072] Specifically, the copper wire is wound on an acrylic or glass plate of suitable size. The length of the acrylic or glass plate may be 15 to 20 cm, and the width may be greater than or equal to 10 cm. The diameter of the copper wire may range from 22 to 50 μm.

[0073] 2. Provide a first insulating adhesive layer 21, wrap the two sides of the metal wire 10 on the support (acrylic / glass plate), extend the first insulating adhesive layer 11 from one end of all the metal wires 10 to the other end along the length direction of the metal wire 10 and stick it to one side surface of a part of the length of each layer of metal wire 10. The length of the first insulating adhesive layer 21 in the length direction of the metal wire 10 is 10 to 17 cm, and 3 to 5 cm of the metal wire 10 (copper wire) is reserved at the bottom of the support (acrylic / glass plate) without the first insulating adhesive layer 21.

[0074] 3. Remove the insulating layer 111 on the outer surface of the metal wire 10 exposed outside the first insulating adhesive layer 21 on the support to form the second part 12; the metal wire 10 without the first insulating adhesive layer 21 can be soaked in concentrated sulfuric acid (fresh concentrated sulfuric acid is soaked for 20 minutes, and used concentrated sulfuric acid is soaked for 30 to 40 minutes). After the soaking is completed, the metal wire 10 and the concentrated sulfuric acid on the acrylic / glass plate are rinsed with alcohol. Observe whether the enameled wire on the surface of the metal wire 10 soaked in concentrated sulfuric acid falls off under an ultra-depth microscope. If it falls off, the soaking is completed. If not, continue to soak in concentrated sulfuric acid.

[0075] 4. Separate the metal wires 10 with the first insulating adhesive layer 21 on both sides of the support (acrylic / glass plate) and peel them off from the support (acrylic / glass plate) respectively. Use a knife to separate the metal wires 10 on both sides of the support (acrylic / glass plate) (make a cut on the top (the side not soaked in concentrated sulfuric acid) and bottom (the side soaked in concentrated sulfuric acid) of the acrylic / glass plate around the metal wires 10), tear off the first insulating adhesive layer 21 from the acrylic / glass plate, and the metal wires 10 will be peeled off from the acrylic / glass plate together with the first insulating adhesive layer 21. Be careful not to stick the bare metal wires 110 soaked in concentrated sulfuric acid to the first insulating adhesive layer 21.

[0076] 5. Provide a second insulating adhesive layer 22 , and adhere the second insulating adhesive layer 22 to the first insulating adhesive layer 21 on the other side surface of each layer of metal wires 10 .

[0077] Specifically, the first insulating adhesive layer 21 with the metal wire 10 adhered thereto may be oriented upward, and then the second insulating adhesive layer 22 may be attached to the first insulating adhesive layer 21, and the top of the second insulating adhesive layer 22 may be folded toward the first insulating adhesive layer 21 and attached to the outside of the first insulating adhesive layer 21. The purpose of folding the second insulating adhesive layer 22 toward the first insulating adhesive layer 21 is to facilitate the stripping of metal wires, such as copper wires, from the insulating adhesive layer after the three-electrode battery is prepared. The stripped copper wires may be soldered to the nickel strip by tin soldering. The high temperature during soldering may cause the enameled wire on the copper wire to fall off. At this time, the copper wire is in a conductive state between the inside of the battery and the nickel strip, and can be used to monitor the positive and negative lithium potentials after lithium plating.

[0078] 6. Cut out the required amount of metal wire.

[0079] Specifically, according to the number of metal wires to be implanted in the three-electrode battery, the metal wires in the insulating glue layer, such as copper wires, can be cut out separately according to the required number, and the cut copper wires can be directly used for the preparation of the three-electrode battery on the production line. There is no need to stick the metal wires one by one in the battery cell, and the required multiple metal wires can be stuck in the battery cell at one time, which simplifies the steps of implanting the metal wires.

[0080] On the other hand, please refer to Figure 2 and Figure 3 and Figure 7 The present application also provides a battery, comprising: an electrode assembly 32, a shell 30 and a top cover 31, the electrode assembly 32 comprises a negative electrode sheet 321, a positive electrode sheet 324 and the aforementioned reference electrode 35, the second portion 12 of the reference electrode 35 and the first portion 11 partially wrapped with an insulating rubber layer 20 are arranged between the positive electrode sheet 324 and the negative electrode sheet 321; the shell 30 has a cavity for accommodating the electrode assembly 32; the top cover 31 is connected to the shell 30, and the reference electrode 35 is sealed and connected to the top cover 31.

[0081] In the technical solution of the embodiment of the present application, the reference electrode 35 is sealed and connected to the top cover 31 , so that the reference electrode 35 has better sealing performance at the connection point with the top cover 31 .

[0082] In some embodiments, please refer to Figure 4 , Figure 5 and Figure 6 A mounting hole 311 is provided on the top cover 31, and a first mounting groove 312 is provided on the side of the mounting hole 311 away from the cavity, a mounting member 33 is fixedly provided on the first mounting groove 312, and a second mounting groove 330 is provided on the side away from the cavity, and a first sealing member 331 is provided on the side facing the cavity, and the first sealing member 331 is provided with a through hole 332 connected with the cavity, and the aperture of the through hole 332 gradually decreases from the outside to the inside of the battery, and the first part 11 wrapped with the insulating rubber layer 20 is interference fit connected with the maximum aperture of the through hole 332, and the reference electrode 35 is inserted into the through hole 332 and a second sealing member 34 is fixed on the second mounting groove 330.

[0083] The first mounting groove 312 may be formed by being concave on the side of the top cover 31 away from the cavity. The mounting member 33 may be a plate-like structure. When the mounting member 33 is mounted on the first mounting groove 312, the top surface of the mounting member 33 may be flush with the top surface of the top cover 31. A first sealing member 331 is provided on the side of the mounting member 33 facing the cavity. The first sealing member 331 is arranged toward the inside of the cavity. The first sealing member 331 is provided with a through hole 332 connected to the cavity. The aperture of the through hole 332 gradually decreases from the outside to the inside of the battery. The first part 11 wrapped with the insulating rubber layer 20 is connected with the maximum aperture of the through hole 332 by interference fit, so that a primary seal is formed between the first part 11 wrapped with the insulating rubber layer 20 and the through hole 332. The first sealing member 331 may be an elastic material with a certain elastic expansion rate, so as to form a seal with the reference electrode 35 through the extrusion of the first sealing member 331.

[0084] The second mounting groove 330 may be formed by being concave on the top surface of the mounting member 33. The second mounting groove 330 is used to fix the second sealing member 34. The second sealing member 34 may be formed by applying glue between the second mounting groove 330 and the reference electrode 35 and then solidifying it, so as to form a secondary seal between the reference electrode 35 and the through hole 332. After the glue is solidified, the top surface of the second sealing member 34 is flush with the top cover 31.

[0085] In the technical solution of the embodiment of the present application, through the above-mentioned arrangement, an effective seal is formed between the reference electrode 35 and the top cover 31 to ensure the sealing of the battery.

[0086] In some embodiments, please refer to Figure 7 and Figure 8 The electrode assembly 32 also includes: a first diaphragm 322 and a second diaphragm 323, the first diaphragm 322 is arranged on the side of the negative electrode sheet 321 facing the positive electrode sheet 324, the second part 12 of the reference electrode 35 and the first part 11 wrapped with the insulating rubber layer 20 are implanted between the first diaphragm 322 and the positive electrode sheet 324; the second diaphragm 323 is arranged between the reference electrode 35 and the positive electrode sheet 324.

[0087] In the technical solution of the embodiment of the present application, the second part 12 of the reference electrode 35 and the first part 11 wrapped with the insulating rubber layer 20 are implanted between the first diaphragm 322 and the second diaphragm 323, so that the reference electrode 35 is isolated from the negative electrode sheet 321 by the first diaphragm 322, and the reference electrode 35 is isolated from the positive electrode sheet 324 by the second diaphragm 323, which makes it difficult for the reference electrode 35 to directly contact the negative electrode sheet 321 and the positive electrode sheet 324 and cause a short circuit.

[0088] On the other hand, the present application also provides a method for preparing a battery, comprising:

[0089] 1. Provide an electrode assembly 32 , wherein the electrode assembly 32 includes a negative electrode sheet 321 , a positive electrode sheet 324 and the aforementioned reference electrode 35 .

[0090] Specifically, the preparation method of the electrode assembly 32 may be:

[0091] A first diaphragm 322 is attached to the side of the negative electrode 321 facing the positive electrode 324; the second part 12 of the reference electrode 35 and the first part 11 wrapped with the insulating rubber layer 20 are attached to the side of the first diaphragm 322 facing the positive electrode 324; and the implanted length of the first part 11 wrapped with the insulating rubber layer 20 is less than the width of the overhang area of ​​the negative electrode, and the overhang area of ​​the negative electrode refers to the area where the negative electrode protrudes from the positive electrode in the width direction. The connection between the first part 11 and the second part 12 in the reference electrode 35 is located in the overhang area of ​​the negative electrode. The reference electrode 35 and the first diaphragm 322 can be fixed by a first fixing tape, and the first fixing tape is attached to the second part 12 near the first part 11. The width of the first fixing tape is less than the width of the overhang area of ​​the negative electrode.

[0092] The second portion 12 of the reference electrode 35 is close to 1 / 3 to 2 / 3 of the width of the cell on the cell ear side. After the reference electrode 35 is attached, the second diaphragm 323 is attached to the side of the reference electrode 35 facing the positive electrode sheet 324; the second diaphragm 323 is fixed to the first diaphragm 322 with a second fixing tape 325, and the second fixing tape 325 is attached to the overhang area of ​​the negative electrode sheet. The width of the second fixing tape 325 is smaller than the width of the overhang area of ​​the negative electrode sheet, and the length of the second fixing tape 325 is 0.8 to 1.2 cm. The width of the second diaphragm 323 is consistent with the width of the cell, and the length of the second diaphragm 323 is smaller than the length of the cell, and can cover the reference electrode 35. Then the positive electrode sheet 324 is covered on the second diaphragm, and wound into a cell to form an electrode assembly 32.

[0093] 2. Place the electrode assembly 32 in the cavity of the shell 30, then cover the top cover 31 onto the shell 30, and seal the mounting member 33 on the first mounting groove 312 of the mounting hole 311. Pass the reference electrode 35 through the through hole 332 of the mounting member 33 of the top cover 31, apply glue to the second mounting groove 330 of the mounting member 33, and form a second sealing member 34 after the glue is solidified, so that a seal is formed between the reference electrode 35 and the through hole 332, and the packaging is completed.

[0094] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A reference electrode, characterized in that include: At least one metal wire (10), the metal wire (10) comprising a first part (11) and a second part (12), the first part (11) comprising a bare metal wire (110) and an insulating layer (111) wrapped around the outer surface of the bare metal wire, and the second part (12) being the bare metal wire; An insulating rubber layer (20), the insulating rubber layer (20) extending along a first direction and encapsulating the first parts (11) of all the metal wires (10) in the insulating rubber layer (20).

2. The reference electrode according to claim 1, characterized in that The insulating rubber layer (20) comprises a first insulating rubber layer (21) and a second insulating rubber layer (22), wherein the first insulating rubber layer (21) and the second insulating rubber layer (22) are arranged opposite to each other, and the first part (11) of all the metal wires (10) is coated between the first insulating rubber layer (21) and the second insulating rubber layer (22).

3. The reference electrode according to claim 2, characterized in that The first insulating adhesive layer (21) is adhered to one side surface of the first part (11) of all the metal wires (10) along the first direction, and the second insulating adhesive layer (22) is adhered to the first insulating adhesive layer (21) on the other side surface opposite to all the metal wires (10).

4. The reference electrode according to claim 2, characterized in that The first insulating adhesive layer (21) and the second insulating adhesive layer (22) are both fiber adhesive tapes, and pressure-sensitive adhesive is coated on the side of the fiber adhesive tape facing the metal wire (10); The fiber tape contains fiber structures (23) arranged at intervals, the extension direction of the fiber structures (23) is consistent with the extension direction of the metal wire (10), and the diameter of each fiber structure is 5 to 30 microns.

5. The reference electrode according to any one of claims 1 to 4, characterized in that The diameter of the metal wire (10) is 22 to 50 micrometers, and the length of the second part of the metal wire (10) is 3 to 5 cm.

6. The reference electrode according to any one of claims 2 to 4, characterized in that The thickness of the first insulating adhesive layer (21) or the second insulating adhesive layer (22) is 20 to 70 μm.

7. The reference electrode according to any one of claims 1 to 4, characterized in that When the metal wires (10) include at least two, all the metal wires (10) are arranged side by side, and the spacing d between two adjacent metal wires (10) satisfies: 0<d<1 mm.

8. A battery, characterized in that: include: An electrode assembly (32), comprising a negative electrode sheet (321), a positive electrode sheet (324) and a reference electrode (35) according to any one of claims 1 to 7, wherein the second portion (12) of the reference electrode (35) and a portion of the first portion (11) wrapped with an insulating rubber layer (20) are arranged between the negative electrode sheet (321) and the positive electrode sheet (324); A housing (30) having a cavity for accommodating the electrode assembly (32); A top cover (31) is connected to the housing (30), and the reference electrode (35) is sealed and connected to the top cover (31).

9. The battery according to claim 8, characterized in that The top cover (31) is provided with a mounting hole (311), the mounting hole (311) is provided with a first mounting groove (312) on a side away from the cavity, a mounting member (33) is fixedly provided on the first mounting groove (312), the mounting member (33) is provided with a second mounting groove (330) on a side away from the cavity, the mounting member (33) is provided with a first sealing member (331) on a side facing the cavity, the first sealing member (331) is provided with a through hole (332) communicating with the cavity, the aperture of the through hole (332) gradually decreases from the outside to the inside of the battery, and the first part (11) wrapped with the insulating rubber layer (20) is interference-fittedly connected with the maximum aperture of the through hole (332), the reference electrode (35) is inserted into the through hole (332) and a second sealing member (34) is fixed on the second mounting groove (330).

10. The battery according to claim 8, characterized in that The electrode assembly (32) further comprises: A first diaphragm (322) is provided on a side of the negative electrode sheet (321) facing the positive electrode sheet (324), and the second portion (12) of the reference electrode (35) and a portion of the first portion (11) wrapped with an insulating rubber layer (20) are implanted between the first diaphragm (322) and the positive electrode sheet (324); The second diaphragm (323) is disposed between the reference electrode (35) and the positive electrode sheet (324).

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