Non-destructive cylindrical battery in-situ three-electrode and preparation method thereof

Abstract

The application provides a non-destructive cylindrical battery in-situ three-electrode and a preparation method thereof. The preparation method comprises the following steps: performing passivation treatment on a micron metal wire, performing winding operation on a micron metal insulation cladding body, a positive electrode, a negative electrode and a separator, exposing the micron metal insulation cladding body partially outside a winding core to form a lead-out wire, placing the winding core in a cylindrical shell, performing liquid injection operation on the battery winding core, separating a sealing gasket of a battery cover cap from a cover plate to form a passage, so that the lead-out wire passes out of the passage to form a reference electrode, performing sealing and pressing operation on the cover plate, and performing sealing operation on a semi-finished battery to obtain the cylindrical battery in-situ three-electrode. By the method, the cylindrical shell does not need to be opened or cut, and an additional sealing step or a sealing agent does not need to be added, so that the operation is simple and reliable, the sealing effect is good, the sealing difficulty is low, and the manufacturing cost is low.

Description

Technical Field

[0001] This invention relates to the field of cylindrical battery manufacturing technology, and in particular to a non-destructive in-situ three-electrode method for cylindrical batteries and its preparation method. Background Technology

[0002] Three-electrode technology is a method that can test the battery voltage operating range in situ, analyze the working potential of the positive and negative electrodes and the electrode polarization, thus creating conditions for the study of battery degradation mechanism and the optimization of positive and negative electrode material system. It also has very important guiding significance for battery structure design, electrode design, positive and negative electrode ratio, material matching, electrolyte composition optimization and other aspects.

[0003] Currently, when manufacturing three electrodes for traditional cylindrical batteries, auxiliary tools are usually needed to open or cut the cylindrical shell. For example, patent CN106099164A discloses a cylindrical battery three-electrode device and its assembly method, specifically disclosing that the reference electrode post is located in the center of the core hole, and the reference electrode is fixed and led out by upper and lower mold bolts. Another example is patent CN107607873A, which discloses an in-situ three-electrode cylindrical battery and its preparation method, specifically disclosing that the cylindrical shell is laser-drilled to form holes so that micron-sized metal wires can be led out of the holes and encapsulated with ultraviolet glue, which can realize the monitoring of the positive and negative electrode voltages inside the battery. Yet another example is patent CN 217035742U, which discloses a large cylindrical lithium-ion three-electrode battery, which achieves the lead-out of the reference electrode metal wire by setting an outlet hole at the top of the shell for the reference electrode metal wire to pass through.

[0004] Therefore, it is evident that the traditional method of fabricating three electrodes for cylindrical batteries is not only complex but also requires auxiliary tools for drilling or cutting, increasing manufacturing costs and damaging the original structure of the cylindrical battery, thus increasing the difficulty of sealing it. Therefore, there is an urgent need to develop a simple and reliable method for fabricating in-situ three electrodes for cylindrical batteries that does not damage the original structure and effectively reduces sealing difficulties. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a non-destructive in-situ three-electrode cylindrical battery, which is simple and reliable to operate, has good sealing effect, low sealing difficulty and low manufacturing cost.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A non-destructive in-situ three-electrode system for a cylindrical battery and its fabrication method, comprising the following steps:

[0008] Obtain a micron-sized metal wire, wherein the micron-sized metal wire does not react with lithium ions;

[0009] The micron-sized metal wire is passivated to obtain a micron-sized metal insulating coating.

[0010] The micron-sized metal insulating cladding, positive electrode, negative electrode, and separator are wound together to obtain a core, wherein a portion of the micron-sized metal insulating cladding is exposed on the outside of the core to form a lead wire, and the micron-sized metal insulating cladding, the positive electrode, and the negative electrode are separated by the separator.

[0011] The winding core is placed inside a cylindrical shell to obtain a battery winding core;

[0012] The battery core is injected with liquid.

[0013] The sealing gasket of the battery cap is separated from the cover plate to form a passage, so that the lead wire can pass through the passage to form a reference electrode, wherein the sealing gasket and the cover plate are detachable;

[0014] The cover plate is sealed and pressed together to obtain a semi-finished battery;

[0015] The semi-finished battery is sealed to obtain a cylindrical battery with three electrodes in situ.

[0016] In one embodiment, the passivation process for the micron-sized metal wire includes the following specific steps:

[0017] The micron-sized metal wire was immersed in a polyurethane conformal coating solution.

[0018] In one embodiment, before the passivation treatment of the micron-sized metal wire and after the step of obtaining the micron-sized metal wire, the following step is further included:

[0019] The micron-sized metal wire is immersed in an acid solution.

[0020] The tip of the micron-sized metal wire is polished after the soaking operation.

[0021] In one embodiment, before the step of injecting liquid into the battery core and after the step of placing the core into the cylindrical housing, the following step is further included:

[0022] The lead wire is wound around the tab of the positive current collector.

[0023] In one embodiment, after the step of sealing and pressing the cover plate and before the step of sealing the semi-finished battery, the following step is further included:

[0024] The excess lead wire is housed within the receiving cavity of the cover plate.

[0025] In one embodiment, the diameter of the micron-sized metal wire is 10 μm to 100 μm.

[0026] In one embodiment, the micron-sized metal insulating cladding includes the micron-sized metal wire and an insulating cladding film, wherein the insulating cladding film is disposed on the outer surface of the micron-sized metal wire.

[0027] In one embodiment, the length of the micron-sized metal wire is 10 cm to 20 cm; and / or,

[0028] The micron-sized metal wire is one of micron-sized copper wire, micron-sized platinum wire, and micron-sized nickel wire.

[0029] In one embodiment, during the winding operation of the micron-sized metal insulating cladding, the positive electrode, the negative electrode, and the separator, the micron-sized metal insulating cladding is disposed on one side of the positive electrode, and the micron-sized metal insulating cladding is separated from the positive electrode by the separator, or...

[0030] The micron-sized metal insulating cladding is disposed on one side of the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode by the diaphragm, or...

[0031] The micron-sized metal insulating cladding is disposed between the positive electrode and the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode and the positive electrode by the diaphragm.

[0032] A non-destructive in-situ three-electrode system for cylindrical batteries is obtained by the preparation method of the non-destructive in-situ three-electrode system for cylindrical batteries described in any of the above embodiments.

[0033] Compared with the prior art, the present invention has at least the following advantages:

[0034] 1. The above-mentioned non-destructive in-situ three-electrode preparation method for cylindrical batteries involves passivating micron-sized metal wires to form an insulating coating on their surface. This coating effectively protects the wires, preventing oxidation and preventing breakage during cover plate pressing. This ensures the lead wires of the micron-sized metal within the insulating coating can emerge intact to form the reference electrode. Furthermore, the insulating coating isolates the wires from the positive electrode, preventing surface detachment and short circuits, thus improving the reference electrode yield.

[0035] 2. The above-described non-destructive in-situ three-electrode fabrication method for a cylindrical battery allows for the separation of the sealing gasket and cover plate to form a passageway. This allows the lead wires to pass through the passageway between the sealing gasket and cover plate, with the lead wires exposed outside the cover plate. Specifically, the lead wires are led out from the gap between the sealing gasket and cover plate, forming a reference electrode. Subsequently, a sealing and pressing operation is performed on the cover plate to press and seal the lead wires in the passageway onto the sealing gasket, thereby achieving a seal on the cylindrical casing. Furthermore, because the sealing gasket and the micron-sized metal insulating cladding undergo certain deformation during sealing and pressing, the cover plate provides an excellent sealing effect on the cylindrical casing. This method eliminates the need for drilling or cutting into the cylindrical casing and requires no additional sealing steps or sealants, effectively avoiding damage to the cylindrical casing structure that would increase the difficulty of sealing the cylindrical battery. This enables the non-destructive fabrication of in-situ three electrodes for cylindrical batteries. The method is not only simple and reliable to operate, but also provides good sealing performance, low sealing difficulty, and low manufacturing cost. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a flowchart of a method for preparing a non-destructive in-situ three-electrode cylindrical battery according to an embodiment of the present invention;

[0038] Figure 2 This is a rate performance test diagram of a non-destructive cylindrical battery with in-situ three electrodes according to an embodiment of the present invention.

[0039] Figure 3This is a schematic diagram of the core structure of a non-destructive cylindrical battery in-situ three electrodes before winding, according to an embodiment of the present invention.

[0040] Figure 4 This is a schematic diagram of the structure of a non-destructive cylindrical battery in situ with its lead wires wound around the tab of the positive electrode current collector according to an embodiment of the present invention.

[0041] Figure 5 This is a schematic diagram of the structure of the lead wire wound around the tab of the positive electrode current collector during the liquid injection of the battery core according to one embodiment of the present invention.

[0042] Figure 6 This is a schematic diagram of the lead wire passage of the in-situ three electrodes of a non-destructive cylindrical battery according to an embodiment of the present invention.

[0043] Figure 7 This is an exploded view of the in-situ three electrodes of a non-destructive cylindrical battery according to an embodiment of the present invention.

[0044] Figure 8 This is a cross-sectional view of a micron-sized metal insulating cladding according to an embodiment of the present invention.

[0045] Figure label:

[0046] 10. Non-destructive cylindrical battery in-situ three electrodes; 100. Cylindrical casing; 200. Core; 210. Positive electrode; 220. Separator; 230. Negative electrode; 300. Positive electrode current collector; 310. Body; 311. Injection port; 320. Terminal lug; 400. Battery cap; 410. Sealing gasket; 420. Cover plate; 421. Receiving cavity; 422. Boss; 430. Passage; 440. Connecting plate; 500. Micron-sized metal insulating cladding; 510. Micron-sized metal wire; 520. Insulating cladding film; 530. Lead wire. Detailed Implementation

[0047] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0048] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] This application provides a non-destructive in-situ three-electrode method for a cylindrical battery, comprising the following steps: obtaining a micron-sized metal wire; passivating the micron-sized metal wire to obtain a micron-sized metal insulating cladding; winding the micron-sized metal insulating cladding, the positive electrode, the negative electrode, and the separator to obtain a core, wherein a portion of the micron-sized metal insulating cladding is exposed on the outside of the core to form a lead wire, and the micron-sized metal insulating cladding, the positive electrode, and the negative electrode are separated by the separator; placing the core into a cylindrical housing to obtain a battery core; injecting electrolyte into the battery core; separating the sealing gasket of the battery cap from the cover plate to form a passage, allowing the lead wire to pass through the passage to form a reference electrode, wherein the sealing gasket and the cover plate are detachable; sealing and pressing the cover plate to obtain a semi-finished battery; and sealing the semi-finished battery to obtain the in-situ three-electrode method for a cylindrical battery.

[0051] The aforementioned method for preparing the in-situ three electrodes of a non-destructive cylindrical battery involves passivating micron-sized metal wires to form an insulating coating on their surface. This coating effectively protects the wires, preventing oxidation and ensuring that they are not easily broken during the subsequent pressing of the cover plate. This ensures that the micron-sized metal leads within the insulating coating can emerge intact to form the reference electrode. Furthermore, the insulating coating isolates the wires from the positive electrode, preventing them from detaching and short-circuiting, thus improving the reference electrode yield. Furthermore, in the aforementioned method for fabricating the non-destructive in-situ three electrodes of a cylindrical battery, the sealing gasket and cover plate are detachable, allowing the user to separate them to form a passage. This allows the lead wires to pass through the passage between the sealing gasket and cover plate, exposing them outside the cover plate. In other words, the lead wires are led out from the gap between the sealing gasket and cover plate, forming a reference electrode. Subsequently, a sealing and pressing operation is performed on the cover plate, pressing and sealing the lead wires in the passage onto the sealing gasket, thereby achieving a seal on the cylindrical casing. Furthermore, because the sealing gasket and the micron-sized metal insulating cladding undergo certain deformation during sealing and pressing, the cover plate provides an excellent sealing effect on the cylindrical casing. This method eliminates the need for drilling or cutting into the cylindrical casing and requires no additional sealing steps or sealants, effectively avoiding damage to the cylindrical casing structure that would increase the difficulty of sealing the cylindrical battery. This enables the non-destructive fabrication of in-situ three electrodes for cylindrical batteries. The method is not only simple and reliable to operate, but also provides good sealing performance, low sealing difficulty, and low manufacturing cost.

[0052] Please see Figure 1 To better understand the technical solution and beneficial effects of this application, the following detailed description is provided in conjunction with specific embodiments. One embodiment of the method for preparing a non-destructive in-situ three-electrode cylindrical battery includes some or all of the following steps:

[0053] S110. Obtain a micron-sized metal wire, wherein the micron-sized metal wire does not react with lithium ions, for later use.

[0054] S120. The micron-sized metal wire is passivated to obtain a micron-sized metal insulating coating.

[0055] It is understandable that by passivating the micron-sized metal wire, an insulating coating film can be formed on the surface of the wire. This film provides excellent protection for the wire, preventing oxidation and ensuring that the wire is not easily broken during the subsequent pressing of the cover plate. This ensures that the lead wires of the micron-sized metal within the insulating coating can emerge intact from the path to form the reference electrode. Furthermore, the insulating coating film isolates the wire from the positive electrode, preventing it from detaching and causing a short circuit, thus improving the yield of the reference electrode.

[0056] S130. The micron-sized metal insulating coating, positive electrode, negative electrode and separator are wound together to obtain a core, wherein the micron-sized metal insulating coating is partially exposed on the outside of the core to form a lead wire, and the micron-sized metal insulating coating, the positive electrode and the negative electrode are separated by the separator.

[0057] It is understandable that by separating the micron-sized metal insulating cladding, the positive electrode, and the negative electrode with a diaphragm to avoid short circuits between them, the micron-sized metal insulating cladding, the positive electrode, the negative electrode, and the diaphragm are then wound together so that part of the micron-sized metal insulating cladding is embedded inside the core, while the other part is exposed outside the core to form a lead wire. This allows the micron-sized metal insulating cladding to be embedded in the core for subsequent formation of a reference electrode.

[0058] S140. Place the core inside a cylindrical housing to obtain a battery core.

[0059] S150. Perform an electrolyte injection operation on the battery core to inject electrolyte into the battery core.

[0060] S160. Separate the sealing gasket of the battery cap from the cover plate to form a passage, so that the lead wire can pass through the passage to form a reference electrode, wherein the sealing gasket and the cover plate are detachable.

[0061] Understandably, since the gasket and cover are detachable, users can separate the gasket and cover to form a passage, allowing the lead wire to pass through the passage between the gasket and cover and expose the lead wire outside the cover. That is, the lead wire is led out from the gap between the gasket and cover, thereby forming a reference electrode. This allows users to lead out the lead wire from the cylindrical housing without making holes or cutting, and without adding additional sealing steps or sealant. The operation is simple and reliable.

[0062] S170. Perform a sealing and pressing operation on the cover plate to obtain a semi-finished battery.

[0063] It is understandable that by performing a sealing and pressing operation on the cover plate, the cover plate can press and seal the lead wire located in the passage onto the sealing gasket, thereby achieving a seal on the cylindrical shell. Furthermore, since the sealing gasket and the micron-sized metal insulating cladding will undergo certain deformation during the sealing and pressing process, the cover plate can achieve a good sealing effect on the cylindrical shell.

[0064] S180. The semi-finished battery is sealed so that the cylindrical shell can be grooved and fixed to the cover plate, thereby further improving the sealing performance between the cover plate and the cylindrical shell, and thus obtaining a cylindrical battery with good sealing effect in situ three electrodes.

[0065] The aforementioned method for preparing the in-situ three electrodes of a non-destructive cylindrical battery involves passivating micron-sized metal wires to form an insulating coating on their surface. This coating effectively protects the wires, preventing oxidation and ensuring that they are not easily broken during the subsequent pressing of the cover plate. This ensures that the micron-sized metal leads within the insulating coating can emerge intact to form the reference electrode. Furthermore, the insulating coating isolates the wires from the positive electrode, preventing them from detaching and short-circuiting, thus improving the reference electrode yield.

[0066] Furthermore, in the above-mentioned method for preparing the non-destructive in-situ three electrodes of a cylindrical battery, since the sealing gasket and the cover plate are detachable, the user can separate the sealing gasket and the cover plate to form a passage, so that the lead wire can pass through the passage between the sealing gasket and the cover plate and expose the lead wire outside the cover plate. That is, the lead wire is led out from the gap between the sealing gasket and the cover plate to form a reference electrode. Then, the cover plate is sealed and pressed to press and seal the lead wire located in the passage onto the sealing gasket, thereby achieving a seal on the cylindrical shell.

[0067] Furthermore, because the sealing gasket and the micron-sized metal insulating cladding undergo certain deformation during sealing and pressing, the cover plate can achieve a good sealing effect on the cylindrical shell. This method eliminates the need for drilling or cutting into the cylindrical shell and requires no additional sealing steps or sealants, effectively avoiding damage to the cylindrical shell structure that would increase the difficulty of sealing the cylindrical battery. This reduces the sealing difficulty and enables the non-destructive in-situ fabrication of the three electrodes for cylindrical batteries. The method is not only simple and reliable to operate, but also provides good sealing performance, low sealing difficulty, and low manufacturing cost.

[0068] In one embodiment, the passivation treatment of the micron-sized metal wire includes the following specific steps: immersing the micron-sized metal wire in a polyurethane conformal coating solution.

[0069] It is understandable that by immersing micron-sized metal wires in a polyurethane conformal coating solution, a polyurethane coating film is formed on the surface of the micron-sized metal wires. Because the polyurethane coating film is not only insulating but also corrosion-resistant, it provides excellent protection for the micron-sized metal wires, effectively preventing oxidation. It is worth mentioning that since the micron-sized metal insulating coating is partially embedded inside the core, this portion is immersed in the electrolyte. The polyurethane coating film on the surface of the micron-sized metal wires further effectively protects them from oxidation caused by the external environment. This allows the reference electrode to accurately detect changes in the positive and negative electrode voltages inside the core, thereby enabling the decomposition of the battery's internal resistance and the determination of the entropy-thermal coefficients of the positive and negative electrodes. (The last sentence appears to be incomplete and possibly refers to a cylindrical shape.) The study of the internal degradation mechanism of batteries and the optimization of positive and negative electrode material systems have created conditions. At the same time, the polyurethane coating film has excellent elasticity, which allows it to deform during the subsequent sealing and pressing operation of the cover plate. This allows the polyurethane coating film to be well pressed and adhered between the sealing gasket and the cover plate, thereby achieving a good seal for the cylindrical shell. In addition, the polyurethane coating film effectively avoids the phenomenon of easily breaking the micron-sized metal wires during the pressing operation of the cover plate, which would cause the scrap of the in-situ three electrodes of the non-destructive cylindrical battery. This ensures that the polyurethane coating film can fully guarantee the integrity of the micron-sized metal insulating coating during the manufacturing process. Thus, on the one hand, it can ensure the obtaining of a reference electrode with high detection accuracy, and on the other hand, it can improve the yield of the in-situ three electrodes of the non-destructive cylindrical battery.

[0070] In one embodiment, the polyurethane conformal coating is a 98% environmentally friendly benzene-free polyurethane conformal coating. It is understood that because the 98% environmentally friendly benzene-free polyurethane conformal coating has excellent insulation, corrosion resistance, and elasticity, and is environmentally friendly, it can form a highly protective, corrosion-resistant, and environmentally friendly polyurethane coating film on the surface of micron-sized metal wires.

[0071] In one embodiment, the micron-sized metal wire is immersed in a polyurethane conformal coating solution for 2 to 10 seconds to allow the outer surface of the micron-sized metal wire to be quickly coated with a polyurethane film. In a preferred embodiment, the immersion time is 5 seconds to form a 5 μm polyurethane film on the surface of the micron-sized metal wire.

[0072] In one embodiment, after the passivation treatment of the micron-sized metal wire and before the winding operation of the micron-sized metal insulating cover, positive electrode, negative electrode and separator, the micron-sized metal insulating cover is further wiped with alcohol to remove excess polyurethane conformal coating solution from the surface of the micron-sized metal insulating cover.

[0073] In one embodiment, before the passivation treatment of the micron-sized metal wire and after the step of obtaining the micron-sized metal wire, the following steps are further included: immersing the micron-sized metal wire in an acid solution; and polishing the tip of the micron-sized metal wire after the immersion operation.

[0074] It is understandable that immersing the micron-sized metal wires in an acid solution serves two purposes: firstly, it removes oil and impurities from the surface of the wires, allowing the polyurethane coating film to directly adhere to their surface; secondly, the acid solution also micro-etches the wires, increasing their surface roughness and enabling the subsequent polyurethane conformal coating solution to better adhere to the wires, thereby enhancing the adhesion between the wires and the polyurethane coating film. Furthermore, in one embodiment, the acid solution is concentrated sulfuric acid, and the immersion time is 30 to 50 minutes, serving as a pretreatment of the micron-sized metal wires.

[0075] It should be noted that the ends of the micron-sized metal wires after being soaked in acid solution are easily corroded into sharp points. If these sharp points are not polished, the ends of the micron-sized metal insulating coating obtained after soaking in polyurethane conformal coating will also be sharp. This will cause the sharp-pointed micron-sized metal insulating coating to easily puncture the attached separator during the winding process with the positive electrode, negative electrode, and separator, leading to a short circuit in the cylindrical battery. Furthermore, during the charging and discharging of the cylindrical battery, lithium ions can easily form lithium dendrites at the sharp points, reducing the accuracy and reliability of the reference electrode detection and thus lowering the accuracy of the reference electrode detection. Therefore, this application grinds the tip of the micron-sized metal wire after the immersion operation to make the tip of the micron-sized metal wire smooth. This allows lithium ions to form a uniform lithium deposition at the smooth end of the micron-sized metal insulating coating, thereby improving the accuracy and reliability of the reference electrode detection. At the same time, the smooth end also effectively avoids puncturing the separator and causing a short circuit in the cylindrical battery, thus improving the yield of the in-situ three electrodes for manufacturing non-destructive cylindrical batteries.

[0076] In one embodiment, the step of polishing the tip of the micron-sized metal wire after the soaking operation includes the following specific steps: polishing the tip of the micron-sized metal wire with sandpaper to achieve the polishing treatment of the tip of the micron-sized metal wire.

[0077] Furthermore, in one embodiment, the tip is first polished by holding a micron-sized metal wire and rubbing the tip back and forth on sandpaper 2 to 3 times. Then, the two sides of the tip are each rubbed back and forth on sandpaper 2 to 3 times to polish the sides of the tip, effectively removing the sharp edges and making the tip smooth. This method is simple to operate and has low manufacturing costs. In a preferred embodiment, the tip is rubbed back and forth on sandpaper twice by holding a micron-sized metal wire, and then the two sides of the tip are each rubbed back and forth on sandpaper 3 times by holding a micron-sized metal wire.

[0078] Please see Figure 4 and Figure 5 In one embodiment, before the step of injecting electrolyte into the battery core 200 and after the step of placing the core 200 into the cylindrical housing 100, the following step is further included: winding the lead wire 530 around the tab 320 of the positive current collector 300 so that the lead wire 530 can be completely wound around the tab 320, so that the subsequent automatic electrolyte injection equipment can quickly and accurately perform automatic electrolyte injection on the battery core 200, thereby avoiding electrolyte splashing and waste. That is, if the lead wire 530 is not wound around the tab 320 of the positive current collector 300, the lead wire 530 is located inside the injection port 311. When the automatic electrolyte injection equipment performs electrolyte injection, the electrolyte will splash due to the obstruction of the lead wire 530 inside the injection port 311, resulting in electrolyte waste and increasing the manufacturing cost. Furthermore, for some automatic liquid injection equipment, the liquid injection nozzle needs to be inserted into the liquid injection port 311 for liquid injection. The lead wire 530 is prone to getting tangled with the automatic liquid injection equipment. For example, the lead wire 530 is easy to get caught on the protruding locking part. When the liquid injection nozzle of the automatic liquid injection equipment is separated from the battery core 200, the lead wire 530 is prone to breakage, which will cause the cylindrical battery in-situ three electrodes to be scrapped, thereby reducing the yield of the cylindrical battery in-situ three electrodes.

[0079] Further, please refer to Figure 5In one embodiment, the positive current collector 300 includes a body 310 and an electrode tab 320 connected to each other. The body 310 has an injection port 311 so that the lead wire 530 can pass through the injection port 311. The electrode tab 320 can be folded onto the side wall of the injection port 311 so that the user can fold the electrode tab 320 upward to expose the injection port 311. The electrode tab 320 stands upright on the body 310 so that the lead wire 530 can be well wound around the electrode tab 320 to avoid the phenomenon of electrolyte splashing.

[0080] In one embodiment, after the battery core is filled with liquid, it is also necessary to untangle the lead wires wrapped around the tabs so that the lead wires can pass through the passage to form a reference electrode.

[0081] In one embodiment, after the step of unwinding the lead wire wrapped around the tab, the method further includes welding the tab to the positive electrode to fix the tab to the positive electrode.

[0082] In one embodiment, after the step of sealing and pressing the cover plate and before the step of sealing the semi-finished battery, the following step is further included: receiving the excess lead wires into the receiving cavity of the cover plate.

[0083] It is understandable that during the sealing operation of semi-finished batteries, the batteries need to rotate at high speed to ensure that the grooving machine can groove the cylindrical shell. This allows the cylindrical shell to better press the cover plate into the cylindrical shell. Therefore, if the excess leads are not housed in the receiving cavity of the cover plate, the excess leads are prone to entanglement between the grooving machine and the semi-finished battery when the battery rotates at high speed, which can cause problems such as lead breakage, semi-finished battery deformation, and jamming of the grooving machine. This not only reduces the yield rate and production efficiency of the in-situ three electrodes of the cylindrical battery, but also increases the maintenance of the grooving machine and increases the manufacturing cost.

[0084] In one embodiment, the cover plate includes a connecting plate 440 and a boss 422 connected to each other. The boss 422 is disposed on the side of the connecting plate 440 facing away from the battery core 200. The boss 422 forms a receiving cavity 421. The receiving cavity 421 has a storage opening so that the user can store the excess lead wire 530 in the receiving cavity 421 through the storage opening, so as to avoid the exposed lead wire 530 from easily getting tangled when the semi-finished battery rotates at high speed.

[0085] To prevent the lead wire 530 housed in the receiving cavity 421 from easily falling off during high-speed rotation, the battery cap 400 further includes a rubber plug. This rubber plug is detachably disposed within the storage opening, allowing it to secure any excess lead wire 530 within the receiving cavity 421, thus preventing it from easily falling off during high-speed rotation. Furthermore, the rubber plug is a silicone plug, which is adapted to the storage opening to achieve sealing and fixation of the opening.

[0086] In one embodiment, after sealing the semi-finished battery, the lead wire is removed from the receiving cavity to complete the fabrication of the in-situ three electrodes of the cylindrical battery.

[0087] In one embodiment, the diameter of the micron-sized metal wire is 10 μm to 100 μm. It is understood that by setting the diameter of the micron-sized metal wire to 10 μm to 100 μm, the size of the micron-sized metal wire is moderate, resulting in a appropriately sized micron-sized metal insulating cladding. This avoids the micron-sized metal insulating cladding being too small, which could easily break during cover plate pressing, and also avoids the micron-sized metal insulating cladding being too large, which could affect the sealing effect on the cylindrical shell during cover plate pressing, thereby causing poor sealing of the in-situ three electrodes of the cylindrical battery and resulting in deterioration of the cylindrical battery's electrical performance. In a preferred embodiment, the diameter of the micron-sized metal wire is 10 μm to 20 μm.

[0088] Please see Figure 8 In one embodiment, the micron-sized metal insulating cladding 500 includes the micron-sized metal wire 510 and an insulating cladding film 520, wherein the insulating cladding film 520 is disposed over the outer surface of the micron-sized metal wire 510 to obtain the micron-sized metal insulating cladding 500. In one embodiment, the micron-sized metal wire 510 is one of micron-sized copper wire, micron-sized platinum wire, and micron-sized nickel wire.

[0089] Furthermore, the thickness of the insulating coating film is 3μm to 10μm to ensure that the thickness of the insulating coating film 520 is moderate. This allows the insulating coating film 520 to effectively prevent the breakage of the micron-sized metal wires during the pressing of the cover plate, while also ensuring that the insulating coating film can be better pressed and adhered between the sealing gasket and the cover plate to achieve a seal for the cylindrical shell, thereby improving the sealing performance of the cylindrical battery. In one embodiment, the thickness of the insulating coating film is 4μm to 5μm to better ensure the protective effect of the insulating coating film on the micron-sized metal wires and the sealing performance of the cylindrical battery. It is worth mentioning that, since the thickness of the insulating coating film is 4μm to 5μm and the diameter of the micron-sized metal wire is 10μm to 20μm, the thickness of the micron-sized metal insulating coating 500 can better match the gap between the cover plate 420 and the sealing gasket 410 in the in-situ three electrodes of the non-destructive cylindrical battery. That is, while ensuring the integrity of the micron-sized metal wire, the good sealing performance of the in-situ three electrodes of the non-destructive cylindrical battery is also ensured.

[0090] In one embodiment, the length of the micron-sized metal wire is 10cm to 20cm. By setting the length of the micron-sized metal wire to 10cm to 20cm, it is ensured that the length of the micron-sized metal wire can meet the normal manufacturing requirements of the reference electrode.

[0091] In one embodiment, during the winding operation of the micron-sized metal insulating cladding, the positive electrode, the negative electrode, and the separator, the micron-sized metal insulating cladding is disposed on one side of the positive electrode, and the micron-sized metal insulating cladding is separated from the positive electrode by the separator, so that the micron-sized metal insulating cladding can be embedded in the positive electrode.

[0092] Specifically, the micron-sized metal insulating cladding, diaphragm, positive electrode, diaphragm, and negative electrode are stacked sequentially, with the length of the micron-sized metal insulating cladding embedded in the positive electrode being 2 / 3 of the width of the positive electrode. Then, the stacked micron-sized metal insulating cladding, diaphragm, positive electrode, diaphragm, and negative electrode are wound together so that part of the micron-sized metal insulating cladding is embedded in the positive electrode, while the other part is exposed on the outside of the wound core to form a lead wire.

[0093] Of course, the way the micron-sized metal insulating cladding is embedded in the core is not limited to the positive electrode of the core. It can also be embedded in the negative electrode of the core. For example, in other embodiments, the micron-sized metal insulating cladding is disposed on one side of the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode by the diaphragm, so that the micron-sized metal insulating cladding can be embedded in the negative electrode.

[0094] Specifically, please refer to Figure 3The micron-sized metal insulating coating 500, diaphragm 220, negative electrode 230, diaphragm 220, and positive electrode 210 are stacked sequentially, with the length of the micron-sized metal insulating coating 500 embedded in the negative electrode 230 being 2 / 3 of the width of the negative electrode 230. Then, the stacked micron-sized metal insulating coating 500, diaphragm 220, negative electrode 230, diaphragm 220, and positive electrode 210 are wound so that part of the micron-sized metal insulating coating 500 is embedded in the negative electrode 230, and the other part is exposed on the outside of the winding core to form a lead wire.

[0095] For example, in other embodiments, the micron-sized metal insulating cladding is disposed between the positive electrode and the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode and the positive electrode by the diaphragm, so that the micron-sized metal insulating cladding can be embedded between the positive electrode and the negative electrode.

[0096] Specifically, the negative electrode, diaphragm, micron-sized metal insulating cladding, diaphragm, and positive electrode are stacked sequentially, with the length of the micron-sized metal insulating cladding embedded in the negative electrode being 2 / 3 of the width of the negative electrode. Then, the stacked negative electrode, diaphragm, micron-sized metal insulating cladding, diaphragm, and positive electrode are wound so that part of the micron-sized metal insulating cladding is embedded between the positive and negative electrodes, while the other part is exposed on the outside of the wound core to form a lead wire.

[0097] In one embodiment, the length of the embedded core of the micron-sized metal insulating cladding is 2 / 3 of the core width. It can be understood that because the embedded core length of the micron-sized metal insulating cladding is 2 / 3 of the core width, it ensures a high connection strength between the embedded micron-sized metal insulating cladding and the core. Furthermore, the length of the micron-sized metal wire is 10cm to 20cm, allowing the final lead wire to be located near the center of the core. This enables the lead wire to be directly welded to the tab of the reference electrode without additional trimming. This not only saves raw materials but also reduces manufacturing steps, improving the production efficiency of the in-situ three-electrode design for non-destructive cylindrical batteries.

[0098] In one embodiment, the micron-sized metal insulating cladding is separated from the negative electrode by a ceramic diaphragm.

[0099] Please see Figure 6 and Figure 7This application also provides a non-destructive in-situ three-electrode 10 for a cylindrical battery, obtained using the preparation method of the non-destructive in-situ three-electrode 10 for a cylindrical battery described in any of the above embodiments. This method eliminates the need for opening or cutting the cylindrical housing 100, and avoids the need for additional sealing steps or sealants, effectively preventing damage to the cylindrical housing 100 structure that would increase the difficulty of sealing the cylindrical battery. This achieves the fabrication of a non-destructive in-situ three-electrode 10 for a cylindrical battery, which is not only simple and reliable to operate, but also provides good sealing effect, low sealing difficulty, and low manufacturing cost. Therefore, a non-destructive in-situ three-electrode 10 for a cylindrical battery with good sealing effect and accurate detection is obtained. Please refer to [link to relevant documentation]. Figure 2 The positive and negative electrode voltages in the in-situ three electrodes 10 of the non-destructive cylindrical battery are similar to the results of the button battery test in the corresponding voltage plateau region, indicating that the in-situ three electrodes 10 of the non-destructive cylindrical battery prepared by the present invention has high accuracy, that is, it can characterize the real changes of the positive and negative electrode voltages inside the battery in situ.

[0100] Meanwhile, the sealing performance of the 20 non-destructive cylindrical battery in-situ three electrodes 10 obtained by this invention was tested. Specifically, the non-destructive cylindrical battery in-situ three electrodes 10 were immersed in water for 24 hours, and then the 20 non-destructive cylindrical battery in-situ three electrodes 10 were disassembled and tested. No water entered any of the 20 non-destructive cylindrical battery in-situ three electrodes 10, which shows that the non-destructive cylindrical battery in-situ three electrodes 10 obtained by this method have good sealing performance.

[0101] Please see Figures 5 to 7 In one embodiment, the non-destructive cylindrical battery in-situ three-electrode 10 includes a cylindrical shell 100, a core 200, a positive current collector 300, a negative current collector, a battery cap 400, and a micron-sized metal insulating coating 500. The core 200 is disposed within the cylindrical shell 100, and both ends of the core 200 are welded to the positive current collector 300 and the negative current collector, respectively, to form the battery core 200. The battery cap 400 includes a sealing gasket 410 and a cover plate 420. The sealing gasket 410 and the cover plate 420 are detachably disposed so that the sealing gasket 410 and the cover plate 420 are separated to form a passage 430, allowing the other end of the micron-sized metal insulating coating 500 to pass through. The lead wire 530 is formed by passing through the passage 430 between the sealing gasket 410 and the cover plate 420 and being at least partially exposed on the outside of the cylindrical housing 100. One end of the micron-sized metal insulating cladding 500 is embedded in the core 200 so that the micron-sized metal insulating cladding 500 can be fitted into the core 200. The cover plate 420 is used to seal the cylindrical housing 100 to obtain a non-destructive cylindrical battery in-situ three-electrode 10.

[0102] Please see Figure 4 and Figure 5 In one embodiment, the positive current collector 300 includes a body 310 and an electrode tab 320 connected to each other. The body 310 has an injection port 311 so that the lead wire 530 can pass through the injection port 311. The electrode tab 320 can be folded onto the side wall of the injection port 311 so that the user can fold the electrode tab 320 upward to expose the injection port 311. The electrode tab 320 stands upright on the body 310 so that the lead wire 530 can be well wound around the electrode tab 320.

[0103] Please see Figure 6 and Figure 7 In one embodiment, the cover plate 420 is formed with a receiving cavity 421 for receiving excess lead wires 530.

[0104] Further, please refer to Figure 7 In one embodiment, the cover plate 420 includes a connecting plate 440 and a boss 422 connected to each other. The boss 422 is disposed on the side of the connecting plate 440 facing away from the battery core 200. The boss 422 forms a receiving cavity 421. The receiving cavity 421 has a storage opening so that the user can store the excess lead wire 530 in the receiving cavity 421 through the storage opening, so as to avoid the phenomenon that the long lead wire 530 is easy to entangle when the semi-finished battery rotates at high speed.

[0105] Compared with the prior art, the present invention has at least the following advantages:

[0106] 1. The above-mentioned non-destructive in-situ three-electrode preparation method for cylindrical batteries involves passivating micron-sized metal wires to form an insulating coating on their surface. This coating effectively protects the wires, preventing oxidation and preventing breakage during cover plate pressing. This ensures the lead wires of the micron-sized metal within the insulating coating can emerge intact to form the reference electrode. Furthermore, the insulating coating isolates the wires from the positive electrode, preventing surface detachment and short circuits, thus improving the reference electrode yield.

[0107] 2. In the above-described non-destructive in-situ three-electrode fabrication method for a cylindrical battery, the sealing gasket and cover plate are detachable, allowing the user to separate them to form a passage. This allows the lead wires to pass through the passage between the sealing gasket and cover plate, with the lead wires exposed outside the cover plate. In other words, the lead wires are led out from the gap between the sealing gasket and cover plate, forming a reference electrode. Subsequently, a sealing and pressing operation is performed on the cover plate to press and seal the lead wires in the passage onto the sealing gasket, thereby achieving a seal on the cylindrical casing. Furthermore, because the micron-sized metal insulating cladding undergoes a certain deformation during sealing and pressing, the cover plate provides an excellent sealing effect on the cylindrical casing. This method eliminates the need for drilling or cutting into the cylindrical casing and requires no additional sealing steps or sealants, effectively avoiding damage to the cylindrical casing structure that would increase the difficulty of sealing the cylindrical battery. This enables the non-destructive fabrication of in-situ three electrodes for cylindrical batteries, offering advantages such as simple and reliable operation, excellent sealing performance, low sealing difficulty, and low manufacturing cost.

[0108] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for fabricating a non-destructive in-situ three-electrode cylindrical battery, characterized in that, Includes the following steps: Obtain a micron-sized metal wire, wherein the micron-sized metal wire does not react with lithium ions; The micron-sized metal wire is passivated to obtain a micron-sized metal insulating coating; wherein the micron-sized metal wire is immersed in a polyurethane conformal coating solution for 2 to 10 seconds to form an insulating coating film with a thickness of 3 μm to 10 μm. The micron-sized metal insulating coating, positive electrode, negative electrode, and diaphragm are wound together to obtain a core. The micron-sized metal insulating coating is partially exposed on the outside of the core to form a lead wire, which is located inside the liquid injection port. The micron-sized metal insulating coating, the positive electrode, and the negative electrode are separated by the diaphragm. The winding core is placed inside a cylindrical shell to obtain a battery winding core; Wrap all the lead wires around the tab; The battery core is injected with liquid. The lead wire wrapped around the tab is unwound; The sealing gasket of the battery cap is separated from the cover plate to form a passage, so that the lead wire can pass through the passage to form a reference electrode, wherein the sealing gasket and the cover plate are detachable; The cover plate is sealed and pressed together so that the cover plate can press and seal the lead wire located in the passage onto the sealing gasket to obtain a semi-finished battery. The semi-finished battery is sealed to obtain a cylindrical battery with three electrodes in situ.

2. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, Before the passivation treatment of the micron-sized metal wire and after the step of obtaining the micron-sized metal wire, the following step is also included: The micron-sized metal wire is immersed in an acid solution. The tip of the micron-sized metal wire is polished after the soaking operation.

3. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, Before the step of injecting liquid into the battery core, and after the step of placing the core into the cylindrical housing, the following step is also included: The lead wire is wound around the tab of the positive current collector.

4. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, After the step of sealing and pressing the cover plate, and before the step of sealing the semi-finished battery, the following steps are also included: The excess lead wire is housed within the receiving cavity of the cover plate.

5. The method for preparing a non-destructive in-situ three-electrode cylindrical battery according to claim 1, characterized in that, The diameter of the micron-sized metal wire is 10μm to 100μm.

6. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, The micron-sized metal insulating cladding includes the micron-sized metal wire and an insulating cladding film, wherein the insulating cladding film is disposed on the outer surface of the micron-sized metal wire.

7. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, The length of the micron-sized metal wire is 10cm to 20cm; and / or, The micron-sized metal wire is one of micron-sized copper wire, micron-sized platinum wire, and micron-sized nickel wire.

8. The method for preparing the in-situ three electrodes of a non-destructive cylindrical battery according to claim 1, characterized in that, During the winding operation of the micron-sized metal insulating cladding, positive electrode, negative electrode, and separator, the micron-sized metal insulating cladding is disposed on one side of the positive electrode, and the micron-sized metal insulating cladding is separated from the positive electrode by the separator, or... The micron-sized metal insulating cladding is disposed on one side of the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode by the diaphragm, or... The micron-sized metal insulating cladding is disposed between the positive electrode and the negative electrode, and the micron-sized metal insulating cladding is separated from the negative electrode and the positive electrode by the diaphragm.

9. A non-destructive in-situ three-electrode system for a cylindrical battery, characterized in that... The non-destructive cylindrical battery in-situ three-electrode preparation method described in any one of claims 1 to 8 is used.

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