Preparation method of full-tab three-electrode battery

Abstract

The invention relates to the technical field of batteries, in particular to a preparation method of a full-tab three-electrode battery. The preparation method of the full-tab three-electrode battery comprises the following steps: S1, a preorder process: producing a roll core; s2, a preparation process: combining a metal wire group at least comprising a copper wire and a nickel wire into a reference electrode in a twisting manner; s3, a pretreatment process: removing a surface oxide layer of the reference electrode, and treating the surface roughness of the reference electrode to a preset value; s4, performing an implantation process, namely unfolding the roll core, implanting a reference electrode, and winding the roll core and the reference electrode together; s5, a kneading process: kneading the tabs on the roll core to be flat; and S6, carrying out a subsequent process, and putting the roll core into a shell. The full-tab three-electrode battery is produced by adopting the preparation method of the full-tab three-electrode battery, so that the yield and the measurement precision of the full-tab three-electrode battery can be improved, and the long-term stable operation of the full-tab three-electrode battery is ensured.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for preparing a three-electrode battery with all tabs. Background Technology

[0002] Three-electrode batteries, by introducing a reference electrode, allow for in-situ analysis of voltage changes and impedance between the positive and negative electrodes. The production of full-tab batteries requires flattening the tabs. In existing technologies, there are two process methods for producing full-tab three-electrode batteries. The first method involves flattening the tabs, unwinding the wound core, placing the reference electrode into the unwound core, and then rewinding the core. This first method is prone to damaging the electrodes during the unwinding process, reducing the yield of full-tab three-electrode batteries. The second method involves unwinding the wound core before flattening the tabs, placing the reference electrode into the unwound core, rewinding the core, and finally flattening the tabs. Because the reference electrode is a metal wire, the second method is prone to reference electrode breakage during tab flattening, further reducing the yield of full-tab three-electrode batteries.

[0003] Therefore, there is an urgent need to invent a method for preparing a three-electrode battery with all tabs to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a full-tab three-electrode battery, so as to improve the yield of full-tab three-electrode batteries and meet actual production needs.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] The preparation method of the all-balance three-electrode battery includes the following steps:

[0007] S1, Pre-processing, producing the winding core;

[0008] S2. Preparation process: The reference electrode is prepared by twisting metal wires, including at least copper wires and nickel wires.

[0009] S3. Pretreatment process: remove the surface oxide layer of the reference electrode and process the surface roughness of the reference electrode to a preset value;

[0010] S4. Implantation process: unfold the core and implant the reference electrode, and wind the core and the reference electrode together;

[0011] S5. Flattening process: Flatten the tabs on the core.

[0012] S6. Subsequent process: insert the core into the shell.

[0013] As an optional option, the diameter of each metal wire in the metal wire group is 50-200μm.

[0014] As an optional solution, the pretreatment process uses physical stripping and chemical treatment to remove the surface oxide layer of the reference electrode, and processes the surface roughness of the reference electrode to a preset value;

[0015] And / or, the pretreatment process includes a first treatment stage and a second treatment stage performed sequentially:

[0016] The first processing stage involves mixing the reference electrode and the reducing agent according to a preset mass ratio, followed by heating to carry out a redox reaction; and

[0017] The second processing stage is used to polish the reference electrode after the first processing stage, and to process the surface roughness of the reference electrode to the preset value.

[0018] As an optional solution, in the first processing stage, the reference electrode and the reducing agent are heated by microwave heating.

[0019] And / or, the heating temperature is 200-1000℃;

[0020] And / or, the heating time is 1-10 minutes;

[0021] And / or, the preset mass ratio of the reference electrode to the reducing agent is 1:5 to 1:10;

[0022] And / or, the reducing agent includes carbon powder, activated carbon, urea, ammonium carbonate, ammonium bicarbonate, or ammonium oxalate.

[0023] As an optional step, the second processing stage includes a polishing process;

[0024] The polishing process involves polishing the reference electrode with sandpaper of 1000-1800 grit.

[0025] As an optional solution, the pretreatment process further includes:

[0026] The cleaning stage, which follows the second processing stage, is used to clean the reference electrode.

[0027] As an optional solution, the pretreatment process further includes:

[0028] The detection stage, which follows the second processing stage, is used to detect the surface roughness of the reference electrode.

[0029] As an optional embodiment, in the implantation process, the core has two opposite ends along the winding direction, and the distance between the mating position of the core and the reference electrode and the ends is not less than one-third of the length of the core along the winding direction.

[0030] As an optional solution, in the implantation process, the surface of the reference electrode is covered with a diaphragm;

[0031] And / or, the reference electrode is bonded and fixed to the winding core.

[0032] As an optional solution, after the core is installed in the shell in the subsequent process, the subsequent process further includes:

[0033] The electrolyte injection step is used to inject electrolyte into the battery casing containing the winding core; and

[0034] The sealing process is used to seal the battery casing.

[0035] The beneficial effects of this invention are:

[0036] The method for preparing a three-electrode battery with omni-tab provided by the present invention uses a twisting method to combine metal wires, including at least copper and nickel wires, into a reference electrode. Under the premise that the diameter of the reference electrode remains unchanged, a reference electrode can be prepared using copper and nickel wires with smaller diameters or by adding other types of metal wires, and the actual diameter of the reference electrode can be made to a specified diameter. It is not necessary to use copper and nickel wires or other types of metal wires with larger diameters. This not only reduces costs, but also because nickel metal itself has high tensile strength and heat resistance. In the reference electrode, the nickel wire acts as a "skeleton" and undertakes the main structural support role, which significantly improves the tensile strength of the reference electrode. Copper wire is relatively soft and has excellent plasticity. In the reference electrode, the copper wire can fill the gaps with the nickel wire and fit tightly with the nickel wire or other types of metal wires, so that the multiple strands of wire can better become a whole. When the reference electrode is subjected to external force, the twisted copper and nickel wires, along with other types of metal wires, share the load. This load is evenly distributed across each wire, ensuring that even minor defects in individual wires don't become fatal weaknesses like a single reference electrode. This improves overall reliability and stability. During bending, the wires within the reference electrode can experience slight relative sliding, making it more resistant to repeated bending and vibration than a single reference electrode. This reduces the risk of breakage due to stress concentration, enhancing the structural strength of the reference electrode and preventing breakage during subsequent flattening processes, thus increasing the yield of the three-electrode battery with full tabs. Simultaneously, the stable potential of copper wires and the reduced polarization effect of nickel wires improve the measurement accuracy of the reference electrode made from the copper and nickel wire combination. In addition, the surface oxide layer of the reference electrode is removed in the pretreatment process, and the surface roughness of the pretreated reference electrode is set to a preset value, which improves the uniformity of lithium plating and lays a solid foundation for the long-term stable operation of the subsequent all-tab three-electrode battery. Attached Figure Description

[0037] Figure 1 This is a flowchart of the preparation method of the all-tab three-electrode battery provided in the embodiments of the present invention. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0041] There are two manufacturing processes for all-tab three-electrode batteries. The first process involves flattening the tabs, unwinding the wound core, placing the reference electrode inside, and then rewinding the core. This first process is prone to damaging the electrodes during the unwinding process, reducing the yield rate of the all-tab three-electrode battery. The second process involves unwinding the wound core before flattening the tabs, placing the reference electrode inside, rewinding the core, and finally flattening the tabs. Because the reference electrode is made of metal wire, the second process is prone to reference electrode breakage during the tab flattening process, further reducing the yield rate of the all-tab three-electrode battery.

[0042] To solve the above problems, such as Figure 1 As shown, this embodiment provides a method for preparing a three-electrode battery with all tabs. The method for preparing the three-electrode battery with all tabs includes the following steps:

[0043] S1, Pre-processing, producing the winding core;

[0044] S2. Preparation process: The reference electrode is prepared by twisting metal wires, including at least copper wires and nickel wires.

[0045] S3. Pretreatment process: Remove the surface oxide layer of the reference electrode and process the surface roughness of the reference electrode to a preset value.

[0046] S4. Implantation process: Unfold the core and implant the reference electrode, then wind the core and the reference electrode together.

[0047] S5. Flattening process: Flattening the tabs on the core.

[0048] S6. Subsequent process: insert the core into the shell.

[0049] The method for preparing this omni-tab three-electrode battery involves using a twisting method to combine metal wires, including at least copper and nickel wires, into a reference electrode. While maintaining the same diameter, the reference electrode can be prepared using smaller diameter copper and nickel wires or by adding other types of metal wires, ensuring the actual diameter of the reference electrode is within the specified range. This eliminates the need for larger diameter copper and nickel wires, reducing costs. Furthermore, nickel metal itself possesses high tensile strength and heat resistance. In the reference electrode, the nickel wire acts as a "skeleton," providing the main structural support and significantly improving the tensile strength. Copper wire, being soft and highly malleable, fills the gaps between the copper and nickel wires and adheres tightly to the nickel wire or other types of metal wires, allowing the multiple strands to better integrate into a cohesive whole. When the reference electrode is subjected to external force, the twisted copper and nickel wires, along with other types of metal wires, share the load. This load is evenly distributed across each wire, ensuring that even minor defects in individual wires don't become fatal weaknesses like a single reference electrode. This improves overall reliability and stability. During bending, the wires within the reference electrode can experience slight relative sliding, making it more resistant to repeated bending and vibration than a single reference electrode. This reduces the risk of breakage due to stress concentration, enhancing the structural strength of the reference electrode and preventing breakage during subsequent flattening processes, thus increasing the yield of the three-electrode battery with full tabs. Simultaneously, the stable potential of copper wires and the reduced polarization effect of nickel wires improve the measurement accuracy of the reference electrode made from the copper and nickel wire combination. In addition, the surface oxide layer of the reference electrode is removed in the pretreatment process, and the surface roughness of the pretreated reference electrode is set to a preset value, which improves the uniformity of lithium plating and lays a solid foundation for the long-term stable operation of the subsequent all-tab three-electrode battery.

[0050] Optionally, the diameter of each metal wire in the wire assembly is 50-200 μm, that is, the diameter of the copper wire is 50-200 μm, and the diameter of the nickel wire is 50-200 μm. By limiting the diameter of each metal wire in the wire assembly to 50-200 μm, the structural strength of the copper wire, nickel wire, and other types of metal wires can be guaranteed, solving the problem of easy breakage of the reference electrode due to the small diameter of the metal wire, ensuring the structural strength of the reference electrode, and thus improving the yield of the all-tab three-electrode battery.

[0051] It should be noted that the reference electrode provided in this embodiment is made by twisting a copper wire and a nickel wire together, that is, the metal wire assembly includes a copper wire and a nickel wire. In other embodiments, the specific number of copper wires, the specific number of nickel wires, and the specific number of other types of metal wires (such as zinc wire, chromium wire, silver wire, etc.) in the metal wire assembly can be adjusted according to actual needs. This embodiment does not make specific limitations.

[0052] Furthermore, in this embodiment, the diameter of both the copper and nickel wires is preferably 100 μm. In other embodiments, the diameter of the copper wire can also be any value within the range of 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, or 50-200 μm. Similarly, the diameter of the nickel wire can also be any value within the range of 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, or 50-200 μm. If the metal wire assembly in other embodiments includes other types of metal wires, the diameter of these other types of metals can be any value within the range of 50μm, 60μm, 70μm, 80μm, 90μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, or 50-200μm. This embodiment does not impose specific limitations.

[0053] Optionally, the pretreatment process employs physical stripping and chemical treatment to remove the surface oxide layer of the reference electrode, and to treat the surface roughness of the reference electrode to a preset value. By using physical stripping and chemical treatment to remove the surface oxide layer of the reference electrode and to treat the surface roughness of the reference electrode to a preset value, the pretreatment effect of the reference electrode can be improved, the uniformity of lithium plating can be enhanced, and a solid foundation can be laid for the long-term stable operation of the subsequent all-tab three-electrode battery. In other embodiments, only physical stripping can be used to remove the surface oxide layer of the reference electrode and to treat the surface roughness of the reference electrode to a preset value, or only chemical treatment can be used to remove the surface oxide layer of the reference electrode and to treat the surface roughness of the reference electrode to a preset value; this embodiment does not impose specific limitations.

[0054] In one optional embodiment, the pretreatment process includes a first treatment stage and a second treatment stage performed sequentially. The first treatment stage involves mixing the reference electrode and a reducing agent at a preset mass ratio and then heating to perform a redox reaction. The second treatment stage involves polishing the reference electrode after the first treatment stage to reduce its surface roughness to a preset value. By dividing the pretreatment process into a first and second treatment stage performed sequentially, the first treatment stage involves mixing the reference electrode and a reducing agent at a preset mass ratio and then heating to perform a redox reaction. This redox reaction removes the oxide layer on the reference electrode's surface while simultaneously inducing thermal stress cracks in the oxide layer at high temperatures, achieving physical peeling of the oxide layer and ensuring effective removal of the oxide layer. The second treatment stage involves polishing the reference electrode to reduce its surface roughness to a preset value, thereby improving the uniformity of lithium plating.

[0055] It should be noted that in this embodiment, the preset value is 0.08 μm, that is, the surface roughness Ra of the reference electrode is 0.08 μm. In other embodiments, the preset value can also be adjusted within the range of Ra < 0.1 μm according to actual needs, that is, the preset surface roughness value of the reference electrode can be adjusted according to actual needs. This embodiment does not make specific limitations.

[0056] As an optional approach, microwave heating is used to heat the reference electrode and reducing agent in the first processing stage. Microwave heating not only offers a high heating rate but also ensures uniform heating of both the reference electrode and the reducing agent. Furthermore, microwave heating does not produce open flames, smoke, or exhaust gases, significantly improving the working environment.

[0057] Optionally, the reducing agent includes toner, activated carbon, urea, ammonium carbonate, ammonium bicarbonate, or ammonium oxalate. In this embodiment, toner is preferred as the reducing agent. In other embodiments, the reducing agent may be any one of toner, activated carbon, urea, ammonium carbonate, ammonium bicarbonate, or ammonium oxalate, or other types of reducing agents may be selected according to actual needs. This embodiment does not impose specific limitations.

[0058] Optionally, the preset mass ratio of the reference electrode to the reducing agent is 1:5 to 1:10. In this embodiment, the preset mass ratio of the reference electrode to the reducing agent is preferably 1:5. In other embodiments, the preset mass ratio of the reference electrode to the reducing agent may also be 1:6, 1:7, 1:8, 1:9, or 1:10, or the preset mass ratio of the reference electrode to the reducing agent may be arbitrarily adjusted within the range of 1:5 to 1:10 according to actual needs. This embodiment does not impose specific limitations.

[0059] Optionally, the heating temperature of the reference electrode and reducing agent in the first processing stage is 200-1000℃. In this embodiment, the preferred heating temperature of the reference electrode and reducing agent in the first processing stage is 800℃. In other embodiments, the heating temperature of the reference electrode and reducing agent in the first processing stage can also be 200℃, 300℃, 400℃, 500℃, 600℃, 700℃, 900℃, or 1000℃, or the heating temperature can be arbitrarily adjusted within the range of 200-1000℃ according to actual needs. This embodiment does not impose specific limitations.

[0060] Optionally, the heating time for the reference electrode and reducing agent in the first processing stage is 1-10 minutes. In this embodiment, the heating time for the reference electrode and reducing agent in the first processing stage is preferably 5 minutes. In other embodiments, the heating time for the reference electrode and reducing agent in the first processing stage can also be 1 minute, 2 minutes, 3 minutes, 4 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes, or the heating time can be arbitrarily adjusted within 1-10 minutes according to actual needs. This embodiment does not impose specific limitations.

[0061] In one optional embodiment, the second processing stage includes a polishing step, in which the reference electrode is polished using sandpaper with a mesh size of 1000-1800 to reduce the surface roughness of the reference electrode to a preset value. It should be noted that in this embodiment, the sandpaper used in the polishing step has a mesh size of 1600.

[0062] In other embodiments, the grit of the sandpaper used in the polishing process can be 1000 grit, 1100 grit, 1200 grit, 1300 grit, 1400 grit, 1500 grit, 1700 grit, or 1800 grit, or the grit of the sandpaper can be adjusted arbitrarily within the range of 1000-1800 grit according to actual needs.

[0063] As an optional step, the pretreatment process also includes a cleaning stage, in which the surface of the reference electrode after polishing is wiped with lint-free paper. By wiping the surface of the reference electrode with lint-free paper after polishing, impurities adhering to the surface of the reference electrode can be removed, ensuring the normal operation of the reference electrode in subsequent processes.

[0064] To further ensure the pretreatment effect on the reference electrode, the pretreatment process also includes a detection stage, which is located after the cleaning stage and is used to detect the surface roughness of the reference electrode.

[0065] When the surface roughness of the reference electrode does not reach the preset value, the second processing stage is repeated, that is, the reference electrode is repeatedly polished, and then the surface of the reference electrode is wiped with lint-free paper again and the surface roughness of the reference electrode is detected, so as to process the surface roughness of the area of ​​the reference electrode whose surface roughness does not reach the preset value to the preset value.

[0066] In an optional embodiment of the implantation process, the core has two opposite ends along the winding direction, and the distance between the mating position of the core and the reference electrode and the end is not less than one-third of the length of the core along the winding direction. By ensuring that the distance between the mating position of the core and the reference electrode and the end plate of the core is not less than one-third of the length of the core along the winding direction, it can be guaranteed that after the core winds the reference electrode together, there is still a sufficient length of core to wind around the outer periphery of the reference electrode, thus ensuring the implantation stability of the reference electrode and the core.

[0067] Optionally, the surface of the reference electrode is covered with a diaphragm. By covering the surface of the reference electrode with a diaphragm, direct contact between the reference electrode and the winding core can be avoided, thus improving the protection of the winding core.

[0068] Furthermore, the reference electrode wrapped with a diaphragm is bonded and fixed to the core. Specifically, insulating tape is used to bond and fix the reference electrode wrapped with the diaphragm to the core. By bonding and fixing the reference electrode wrapped with the diaphragm to the core, pre-fixation of the reference electrode to the core can be achieved before the reference electrode is wound into the core, further ensuring the implantation stability of the reference electrode within the core. Understandably, in other embodiments, the reference electrode can also be bonded and fixed to the core without the diaphragm, or the diaphragm can be wrapped around the surface of the reference electrode without it being bonded and fixed to the core.

[0069] Understandably, the production of the core in the preceding process, the flattening of the tabs in the flattening process, and the insertion of the core into the shell in the subsequent process are all existing technologies, and will not be elaborated here.

[0070] After the core is inserted into the battery casing in this embodiment, the subsequent processes also include an electrolyte injection stage and a capping stage. The electrolyte injection stage is used to inject electrolyte into the battery casing containing the core, and the capping stage is used to seal the battery casing. The specific operation steps of the electrolyte injection stage and the capping stage are all prior art and will not be described in detail here.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a three-electrode battery with a full tab, characterized in that, Includes the following steps: S1, Pre-processing, producing the winding core; S2. Preparation process: The reference electrode is prepared by twisting metal wires, including at least copper wires and nickel wires. S3. Pretreatment process: remove the surface oxide layer of the reference electrode and process the surface roughness of the reference electrode to a preset value; S4. Implantation process: unfold the core and implant the reference electrode, and wind the core and the reference electrode together; S5. Flattening process: Flatten the tabs on the core. S6. Subsequent process: insert the core into the shell.

2. The method for preparing a three-electrode battery with a full tab according to claim 1, characterized in that, The diameter of each metal wire in the metal wire group is 50-200μm.

3. The method for preparing a three-electrode battery with a full tab according to claim 1, characterized in that, The pretreatment process uses physical stripping and chemical treatment to remove the surface oxide layer of the reference electrode, and processes the surface roughness of the reference electrode to a preset value; And / or, the pretreatment process includes a first treatment stage and a second treatment stage performed sequentially: The first processing stage is used to mix the reference electrode and the reducing agent according to a preset mass ratio and then heat them to carry out an oxidation-reduction reaction; as well as The second processing stage is used to polish the reference electrode after the first processing stage, and to process the surface roughness of the reference electrode to the preset value.

4. The method for preparing a three-electrode battery with a full tab according to claim 3, characterized in that, In the first processing stage, the reference electrode and the reducing agent are heated by microwave heating; And / or, the heating temperature is 200-1000℃; And / or, the heating time is 1-10 minutes; And / or, the preset mass ratio of the reference electrode to the reducing agent is 1:5 to 1:10; And / or, the reducing agent includes carbon powder, activated carbon, urea, ammonium carbonate, ammonium bicarbonate, or ammonium oxalate.

5. The method for preparing a three-electrode battery with a full tab according to claim 3, characterized in that, The second processing stage includes a polishing step; The polishing process involves polishing the reference electrode with sandpaper of 1000-1800 grit.

6. The method for preparing a three-electrode battery with a full tab according to claim 3, characterized in that, The pretreatment process further includes: The cleaning stage, which follows the second processing stage, involves wiping the surface of the reference electrode with lint-free paper.

7. The method for preparing a three-electrode battery with a full tab according to claim 3, characterized in that, The pretreatment process further includes: The detection stage, which follows the second processing stage, is used to detect the surface roughness of the reference electrode.

8. The method for preparing a three-electrode battery with a full tab according to claim 1, characterized in that, In the implantation process, the core has two opposite ends along the winding direction, and the distance between the mating position of the core and the reference electrode and the ends is not less than one-third of the length of the core along the winding direction.

9. The method for preparing a three-electrode battery with a full tab according to claim 1, characterized in that, In the implantation process, the surface of the reference electrode is covered with a diaphragm; And / or, the reference electrode is bonded and fixed to the winding core.

10. The method for preparing a three-electrode battery with a full tab according to claim 1, characterized in that, After the core is inserted into the housing in the subsequent process, the subsequent process further includes: The electrolyte injection step is used to inject electrolyte into the battery casing containing the winding core; and The sealing process is used to seal the battery casing.

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