Method for producing a chemical conversion foil and chemical conversion foil

Abstract

The present disclosure provides a preparation method of a formation foil and the formation foil. The preparation method of the formation foil comprises: performing multi-stage formation treatment on the formation foil by using a formation electrolyte with a non-ionic surfactant, wherein the concentration of the non-ionic surfactant in the formation electrolyte for multi-stage formation changes in a gradient manner. The present disclosure can significantly improve the voltage resistance performance of the formation foil, the leakage current is lower, and the specific capacity is more stable.

Description

Technical Field

[0001] This disclosure relates to the field of electroforming foil processing technology, and particularly to a method for preparing electroforming foil and an electroforming foil. Background Technology

[0002] Aluminum electrolytic capacitors are widely used in electronic devices, and the quality of their core component, the electrolytic foil, directly affects the capacitor's performance. In traditional electrolytic foil manufacturing processes, the electrolytic solution has a single composition, leading to uneven oxide film growth and surface defects, resulting in problems such as insufficient withstand voltage, high leakage current, and capacitance decay. While existing technologies improve performance by adjusting the electrolyte composition or optimizing process parameters, they are limited by the interaction mechanism between the electrolyte and the aluminum foil surface, making it difficult to fundamentally optimize the oxide film structure. Summary of the Invention

[0003] This disclosure provides a method for preparing electroformed foil and an electroformed foil.

[0004] In a first aspect, embodiments of this disclosure provide a method for preparing a chemically formed foil, comprising: performing a multi-stage chemically formed foil treatment using a chemically formed electrolyte containing added nonionic surfactants, wherein the concentration of the nonionic surfactant in the multi-stage chemically formed electrolyte varies in a gradient.

[0005] In some embodiments, the nonionic surfactant includes polyoxyethylene ether compounds.

[0006] In some embodiments, the concentration gradient of nonionic surfactants in the multi-stage formation electrolyte decreases.

[0007] In some embodiments, the concentration of nonionic surfactant in the electrolytic electrolyte is 0.1 wt% to 1 wt%.

[0008] In some embodiments, the electrolyte comprises an aqueous solution of adipate.

[0009] In some embodiments, the electrolytic electrolyte comprises an aqueous solution of ammonium adipate, wherein the concentration of ammonium adipate is 1 wt% to 20 wt%.

[0010] In some embodiments, a multi-stage formation process is performed on the formed foil using a formation electrolyte containing a nonionic surfactant, including: a primary formation process using a formation electrolyte composed of 1 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound, and deionized water to obtain a primary formed foil; a secondary formation process using a formation electrolyte composed of 7 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound, and deionized water to obtain a secondary formed foil; a tertiary formation process using a formation electrolyte composed of 5 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound, and deionized water to obtain a tertiary formed foil; and a tertiary formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt% polyoxyethylene ether compound, and deionized water to obtain a primary formed foil. The tertiary formed foil is subjected to a quaternary formed process using a forming electrolyte composed of 0.5 wt% polyoxyethylene ether compounds and deionized water to obtain a quaternary formed foil. The quaternary formed foil is then subjected to a pentadic formed process using a forming electrolyte composed of 2 wt%–10 wt% ammonium adipate, 0.1 wt%–0.5 wt% polyoxyethylene ether compounds and deionized water to obtain a pentadic formed foil. Finally, the pentadic formed foil is subjected to a septadic formed process using a forming electrolyte composed of 2 wt%–10 wt% ammonium adipate, 1 wt%–7 wt% phosphate, 0.1 wt%–0.5 wt% polyoxyethylene ether compounds and deionized water to obtain a septadic formed foil.

[0011] In some embodiments, the method further includes adjusting process parameters according to the reaction state of the formed foil.

[0012] In some embodiments, the method further includes: subjecting the formed foil that has undergone multi-stage formation treatment to at least one post-treatment, passivation treatment, heat treatment, and drying treatment.

[0013] Secondly, embodiments of this disclosure provide a chemically formed foil, which is prepared by the chemically formed foil preparation method described in the first aspect of this disclosure.

[0014] In the embodiments of this disclosure, by adding a nonionic surfactant to the formation electrolyte and having the concentration of the nonionic surfactant change in a gradient during the multi-stage formation process, the oxide film can grow uniformly, surface defects can be reduced, thereby significantly improving the withstand voltage performance of the formed foil, resulting in lower leakage current and more stable specific capacitance. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a method for preparing electroforming foil according to an embodiment of this disclosure. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of this disclosure will be described in detail below with reference to the accompanying drawings.

[0017] Exemplary embodiments will be described more fully below with reference to the accompanying drawings; however, these exemplary embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will enable those skilled in the art to fully understand the scope of this disclosure.

[0018] Where there is no conflict, the various embodiments of this disclosure and the features thereof in the embodiments may be combined with each other.

[0019] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded.

[0021] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0022] Firstly, referring to Figure 1 This disclosure provides a method for preparing electroplated foil, comprising:

[0023] S1. The electrolytic foil is subjected to multi-stage electrolytic formation using an electrolytic electrolyte containing nonionic surfactants, wherein the concentration of nonionic surfactants in the electrolytic electrolyte varies in a gradient.

[0024] In this embodiment, due to the unique molecular structure of nonionic surfactants, during the formation process of the aluminum foil using a formation electrolyte with added nonionic surfactants, the hydrophilic and lipophilic groups of the nonionic surfactants can be oriented at the interface between the formation electrolyte and the aluminum foil, significantly reducing interfacial tension. This promotes the penetration of the formation electrolyte into the micropores of the aluminum foil, reduces local reaction blind zones caused by residual bubbles, and makes the oxide film growth more uniform. The steric hindrance effect of nonionic surfactants can inhibit the adsorption of impurity particles on the aluminum foil surface, reducing surface defects. At the same time, the nonionic surfactants and carboxylic acids in the formation electrolyte can form a synergistic adsorption layer, which can improve the performance and stability of the electrochemical system and extend the service life of the electrolyte.

[0025] In the embodiments of this disclosure, during the formation process of the formed foil using a formation electrolyte with added nonionic surfactant, the concentration of nonionic surfactant in the formation electrolyte varies in a gradient. For example, the concentration of nonionic surfactant is controlled according to the voltage applied at each formation stage, so that the growth of the oxide film is synchronized with the action of the nonionic surfactant. This can promote uniform growth of the oxide film and avoid adverse effects of nonionic surfactant on the formation rate.

[0026] In the embodiments of this disclosure, by adding a nonionic surfactant to the formation electrolyte and having the concentration of the nonionic surfactant change in a gradient during the multi-stage formation process, the oxide film can grow uniformly, surface defects can be reduced, thereby significantly improving the withstand voltage performance of the formed foil, resulting in lower leakage current and more stable specific capacitance.

[0027] The formed foil prepared according to the method for preparing formed foil provided in the embodiments of this disclosure has an oxide film uniformity that is improved by more than 50%, a capacity that is improved by more than 3%, and a leakage current that is reduced by more than 25%.

[0028] The embodiments disclosed herein do not impose any special limitations on nonionic surfactants.

[0029] In some embodiments, the nonionic surfactant includes a polyoxyethylene ether compound with the following molecular structure: ,in, .

[0030] In some embodiments, the concentration gradient of nonionic surfactants in the multi-stage formation electrolyte decreases.

[0031] In the multi-stage formation process of the oxide foil, the voltage applied in each stage increases progressively. The first few stages apply lower voltages but higher current densities, resulting in rapid oxide film growth. A higher concentration of nonionic surfactant is added to reduce interfacial tension, improve the wettability of the oxide foil, promote uniform electrolyte distribution, and enhance ion conduction efficiency and oxide film formation. As the voltage increases, if the concentration of nonionic surfactant is too high, excessive nonionic surfactant molecules may accumulate disorderly on the oxide foil surface, increasing surface defects and hindering normal oxide film growth. Therefore, the concentration of nonionic surfactant decreases in later stages to ensure uniform oxide film growth and reduce surface defects.

[0032] In some embodiments, the concentration of nonionic surfactant in the electrolytic electrolyte is 0.1 wt% to 1 wt%.

[0033] In some embodiments, the electrolyte comprises an aqueous solution of adipate.

[0034] In some embodiments, the electrolytic electrolyte comprises an aqueous solution of ammonium adipate, wherein the concentration of ammonium adipate is 1 wt% to 20 wt%.

[0035] In this embodiment, the electrolytic electrolyte is composed of ammonium adipate, polyoxyethylene ether compounds, and deionized water. The carboxyl groups can form hydrogen bonds with the polyoxyethylene chains of the polyoxyethylene ether compounds, while the hydrophobic alkyl chains and the hydrophobic groups of the polyoxyethylene ether compounds combine through hydrophobic interactions. This complex can more effectively reduce interfacial tension, thereby making the oxide film grow uniformly and reducing surface defects.

[0036] In this embodiment of the disclosure, there are no special limitations on how the concentration of nonionic surfactant in the multi-stage formation electrolyte decreases in a gradient manner.

[0037] In some embodiments, a multi-stage formation process is performed on the formed foil using a formation electrolyte containing a nonionic surfactant, including:

[0038] The formed foil is subjected to a primary formation treatment using a formation electrolyte composed of 1 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a primary formed foil.

[0039] The primary formed foil is subjected to a secondary formed process using a forming electrolyte composed of 7 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a secondary formed foil.

[0040] The secondary formed foil is subjected to a tertiary formation process using a formation electrolyte composed of 5 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a tertiary formed foil.

[0041] The three-stage formed foil is subjected to a four-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compound and deionized water to obtain a four-stage formed foil.

[0042] The fourth-stage formed foil is subjected to a fifth-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compounds and deionized water to obtain a fifth-stage formed foil.

[0043] The five-stage formed foil is subjected to a six-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 1 wt%~7 wt% phosphate, 0.1 wt%~0.5 wt% polyoxyethylene ether compound and deionized water to obtain a six-stage formed foil.

[0044] In some embodiments, the method further includes adjusting process parameters according to the reaction state of the formed foil.

[0045] In this embodiment, the electrolytic electrolyte is composed of ammonium adipate, polyoxyethylene ether compounds, and deionized water. The carboxyl groups can form hydrogen bonds with the polyoxyethylene chains of the polyoxyethylene ether compounds, while the hydrophobic alkyl chains and the hydrophobic groups of the polyoxyethylene ether compounds combine through hydrophobic interactions. As the pH of the solution increases, the content of organic carboxylic acid anions increases, and the hydration capacity of the mixed micelles in the electrochemical system is enhanced. Within the pH range of the electrolytic electrolyte, the cloud point of the nonionic surfactant increases, thereby facilitating clearer observation of the reaction state during production and timely adjustment of process parameters.

[0046] In some embodiments, the method further includes: subjecting the formed foil that has undergone multi-stage formation treatment to at least one post-treatment, passivation treatment, heat treatment, and drying treatment.

[0047] In some embodiments, the method for preparing the electrolytic foil includes the following steps:

[0048] The foil will undergo six-stage formation at 20-200 Vf:

[0049] The electrolytic foil is placed in an electrolytic electrolyte composed of 1 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compounds, and deionized water, and then 0.10 A / dm³ is introduced at 60~80°C. 2 ~0.30A / dm2 The current is applied for 5-10 minutes to obtain a primary electrolytic foil.

[0050] After washing with water, the primary formation foil is placed in a formation electrolyte composed of 7 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compounds, and deionized water. A flow rate of 0.10 A / dm³ is then introduced at 60~80°C. 2 ~0.25A / dm 2 The current is applied for 5-15 minutes to obtain a secondary electrolytic foil.

[0051] After washing with water, the secondary formation foil is placed in a formation electrolyte composed of 5 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound, and deionized water, and then 0.10 A / dm³ is introduced at 60~80℃. 2 ~0.25A / dm 2 The current is applied for 7-20 minutes to obtain a three-stage electrolytic foil.

[0052] The three-stage formation foil is washed with water and placed in a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compounds, and deionized water. A flow rate of 0.10 A / dm³ is introduced at 60~80°C. 2 ~0.25A / dm 2 The current is applied for 7-20 minutes to obtain a four-stage electrolytic foil.

[0053] After washing with water, the fourth-stage formation foil is placed in a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compounds, and deionized water, and then 0.10 A / dm³ is introduced at 60~80°C. 2 ~0.25A / dm 2 The current is applied for 10-25 minutes to obtain a five-stage electrolytic foil.

[0054] After washing with water, the five-stage formation foil is placed in a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 1 wt%~7 wt% phosphate, 0.1 wt%~0.5 wt% polyoxyethylene ether compounds, and deionized water. A flow rate of 0.05 A / dm³ is then introduced at 60~80°C. 2 ~0.15A / dm 2 The current is applied for 15-35 minutes to obtain a six-stage electrolytic foil.

[0055] After washing with water, the sample enters the next treatment stage. The electrolyte in this stage consists of a 2 wt% to 10 wt% phosphate solution, and is passed through at 0.05 A / dm³ at a temperature of 70 to 90°C. 2 ~0.15A / dm2 The current is applied for 5-15 minutes.

[0056] After being washed with water, the foil is placed in a 5 wt%-20 wt% phosphoric acid solution and treated at 40-60℃ for 60-180 seconds to obtain a passivated foil.

[0057] After washing with water, the sample enters the second treatment stage. The electrolyte in the second treatment stage consists of a 2 wt% to 10 wt% phosphate solution, and is passed through at 0.05 A / dm³ at a temperature of 70 to 90 °C. 2 ~0.15A / dm 2 The current is applied for 5-15 minutes.

[0058] Subsequently, it is heat-treated at 400~500℃ for 80~180s to obtain heat-treated foil.

[0059] The electrolyte in the final three treatments consists of a 2 wt% to 10 wt% phosphate solution, and is passed through at 0.05 A / dm³ at a temperature of 70 to 90 °C. 2 ~0.15A / dm 2 Apply the current and process for 5-10 minutes.

[0060] Finally, it is dried at 150~250℃ to obtain electrolytic foil.

[0061] Secondly, embodiments of this disclosure provide a chemically formed foil, which is prepared by the chemically formed foil preparation method described in the first aspect of this disclosure.

[0062] Example 1

[0063] The method for preparing electrolytic foil includes the following steps:

[0064] The foil will undergo six-stage formation at a final voltage of 36Vf:

[0065] The electrolytic foil was placed in an electrolytic electrolyte consisting of 15 wt% ammonium adipate, 1 wt% polyoxyethylene ether compound, and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 5 minutes to obtain a primary electrolytic foil.

[0066] After washing with water, the primary formation foil was placed in a formation electrolyte consisting of 10 wt% ammonium adipate, 1 wt% polyoxyethylene ether compound, and deionized water, and then 0.25 A / dm³ was introduced at 70 °C. 2 The current was applied for 5 minutes to obtain a secondary electrolytic foil.

[0067] After washing with water, the secondary formation foil was placed in a formation electrolyte composed of 10 wt% ammonium adipate, 0.7 wt% polyoxyethylene ether compounds, and deionized water, and then 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 8 minutes to obtain a three-stage electrolytic foil.

[0068] The three-stage formation foil was washed with water and placed in a formation electrolyte composed of 5 wt% ammonium adipate, 0.5 wt% polyoxyethylene ether compound, and deionized water. A flow rate of 0.25 A / dm³ was then introduced at 70°C. 2 The current was applied for 8 minutes to obtain a four-stage electrolytic foil.

[0069] After washing with water, the fourth-stage formation foil was placed in a formation electrolyte composed of 5 wt% ammonium adipate, 0.2 wt% polyoxyethylene ether compound, and deionized water, and then 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 10 minutes to obtain a five-stage electrolytic foil.

[0070] After washing with water, the five-stage formation foil was placed in a formation electrolyte composed of 5 wt% ammonium adipate, 4 wt% phosphate, 0.2 wt% polyoxyethylene ether compound, and deionized water, and then 0.15 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a six-stage electrolytic foil.

[0071] After washing with water, the sample enters the next treatment stage. The electrolyte in this stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 8 minutes.

[0072] After being washed with water, the foil was placed in a 15wt% phosphoric acid solution and treated at 50°C for 60 seconds to obtain a passivated foil.

[0073] After washing with water, the sample enters the second treatment stage. The electrolyte for this second treatment stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 6 minutes.

[0074] Subsequently, it was heat-treated at 500℃ for 80 seconds to obtain a heat-treated foil.

[0075] The electrolyte for the final three treatments consists of a 3 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 6 minutes.

[0076] Finally, it is dried at 150°C to obtain electrolytic foil.

[0077] Example 2

[0078] The method for preparing electrolytic foil includes the following steps:

[0079] The foil will undergo six-stage formation at a final voltage of 115Vf:

[0080] The electrolytic foil was placed in an electrolytic electrolyte consisting of 15 wt% ammonium adipate, 1 wt% polyoxyethylene ether compound, and deionized water, and a flow rate of 0.30 A / dm³ was introduced at 70°C. 2 The current was applied for 7 minutes to obtain a primary electrolytic foil.

[0081] After washing the primary formation foil with water, it was placed in a formation electrolyte composed of 15 wt% ammonium adipate, 1 wt% polyoxyethylene ether compound, and deionized water, and then 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 10 minutes to obtain a secondary electrolytic foil.

[0082] After washing with water, the secondary formation foil was placed in a formation electrolyte composed of 15 wt% ammonium adipate, 0.8 wt% polyoxyethylene ether compound, and deionized water, and then 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a three-stage electrolytic foil.

[0083] The three-stage formation foil was washed with water and placed in a formation electrolyte composed of 10 wt% ammonium adipate, 0.5 wt% polyoxyethylene ether compound, and deionized water. A flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a four-stage electrolytic foil.

[0084] After washing with water, the fourth-stage formation foil was placed in a formation electrolyte composed of 10 wt% ammonium adipate, 0.3 wt% polyoxyethylene ether compound, and deionized water, and then 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a five-stage electrolytic foil.

[0085] After washing with water, the five-stage formation foil was placed in a formation electrolyte composed of 10 wt% ammonium adipate, 7 wt% phosphate, 0.1 wt% polyoxyethylene ether compound, and deionized water, and then 0.15 A / dm³ was introduced at 70°C. 2 The current was applied for 20 minutes to obtain a six-stage electrolytic foil.

[0086] After washing with water, the sample enters a subsequent treatment process. The electrolyte in this process consists of a 10 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 10 minutes.

[0087] After being washed with water, the foil was placed in a 20 wt% phosphoric acid solution and treated at 50°C for 60 seconds to obtain a passivated foil.

[0088] After washing with water, the sample enters the second treatment stage. The electrolyte for this second treatment stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 5 minutes.

[0089] Subsequently, it was heat-treated at 500℃ for 100s to obtain a heat-treated foil.

[0090] The electrolyte for the final three treatments consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 5 minutes.

[0091] Finally, it is dried at 150°C to obtain electrolytic foil.

[0092] Comparative Example 1

[0093] The method for preparing electrolytic foil includes the following steps:

[0094] The foil will undergo six-stage formation at a final voltage of 36Vf:

[0095] The electrolytic foil was placed in an electrolytic electrolyte consisting of 15 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 5 minutes to obtain a primary electrolytic foil.

[0096] After washing the primary formation foil with water, it was placed in a formation electrolyte composed of 10wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 5 minutes to obtain a secondary electrolytic foil.

[0097] After washing the secondary formation foil with water, it was placed in a formation electrolyte composed of 10 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 8 minutes to obtain a three-stage electrolytic foil.

[0098] The three-stage formation foil was washed with water and placed in a formation electrolyte consisting of 5 wt% ammonium adipate and deionized water. A flow rate of 0.25 A / dm³ was then introduced at 70°C. 2 The current was applied for 8 minutes to obtain a four-stage electrolytic foil.

[0099] After washing the fourth-stage formation foil with water, it was placed in a formation electrolyte composed of 5 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 10 minutes to obtain a five-stage electrolytic foil.

[0100] After washing the five-stage formation foil with water, it was placed in a formation electrolyte consisting of 5 wt% ammonium adipate, 4 wt% phosphate, and deionized water, and then 0.15 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a six-stage electrolytic foil.

[0101] After washing with water, the sample enters the next treatment stage. The electrolyte in this stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 8 minutes.

[0102] After being washed with water, the foil was placed in a 15 wt% phosphoric acid solution and treated at 50°C for 60 seconds to obtain a passivated foil.

[0103] After washing with water, the sample enters the second treatment stage. The electrolyte for this second treatment stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 6 minutes.

[0104] Subsequently, it was heat-treated at 500℃ for 80 seconds to obtain a heat-treated foil.

[0105] The electrolyte for the final three treatments consists of a 3 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 6 minutes.

[0106] Finally, it is dried at 150°C to obtain electrolytic foil.

[0107] Comparative Example 2

[0108] The method for preparing electrolytic foil includes the following steps:

[0109] The foil will undergo six-stage formation at a final voltage of 115Vf:

[0110] The electrolytic foil was placed in an electrolytic electrolyte consisting of 15 wt% ammonium adipate and deionized water, and a flow rate of 0.30 A / dm³ was introduced at 70°C. 2 The current was applied for 7 minutes to obtain a primary electrolytic foil.

[0111] After washing the primary formation foil with water, it was placed in a formation electrolyte composed of 15 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 10 minutes to obtain a secondary electrolytic foil.

[0112] After washing the secondary formation foil with water, it was placed in a formation electrolyte composed of 15 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a three-stage electrolytic foil.

[0113] The three-stage formation foil was washed with water and placed in a formation electrolyte consisting of 10 wt% ammonium adipate and deionized water. A flow rate of 0.25 A / dm³ was then introduced at 70°C. 2 The current was applied for 15 minutes to obtain a four-stage electrolytic foil.

[0114] After washing the fourth-stage formation foil with water, it was placed in a formation electrolyte composed of 10 wt% ammonium adipate and deionized water, and a flow rate of 0.25 A / dm³ was introduced at 70°C. 2 The current was applied for 15 minutes to obtain a five-stage electrolytic foil.

[0115] After washing the five-stage formation foil with water, it was placed in a formation electrolyte consisting of 10 wt% ammonium adipate, 7 wt% phosphate, and deionized water, and then 0.15 A / dm³ was introduced at 70°C. 2 The current was applied for 20 minutes to obtain a six-stage electrolytic foil.

[0116] After washing with water, the sample enters a subsequent treatment process. The electrolyte in this process consists of a 10 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 5 minutes.

[0117] After being washed with water, the foil was placed in a 20 wt% phosphoric acid solution and treated at 50°C for 60 seconds to obtain a passivated foil.

[0118] After washing with water, the sample enters the second treatment stage. The electrolyte for this second treatment stage consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 5 minutes.

[0119] Subsequently, it was heat-treated at 500℃ for 100s to obtain a heat-treated foil.

[0120] The electrolyte for the final three treatments consists of a 5 wt% phosphate solution, and is passed through at 0.15 A / dm³ at 80°C. 2 The current was applied for 5 minutes.

[0121] Finally, it is dried at 150°C to obtain a foil.

[0122] The performance of the formed foils prepared in the examples and comparative examples was tested, and the results are shown in Table 1.

[0123] Table 1

[0124]

[0125] As can be seen from the data in Table 1, regardless of whether the voltage (36Vf) or high voltage (115Vf) conditions are met, the formed foil of the embodiments exhibits higher withstand voltage, larger specific capacitance, lower dispersion, and lower leakage current. This indicates that the method for preparing the formed foil provided in this disclosure can effectively improve the quality, structural uniformity, and electrochemical stability of the oxide film, resulting in a higher yield and stronger reliability of the formed foil, making it more suitable for applications requiring high performance and high consistency (such as high-end electronic devices and automotive electronics).

[0126] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. A method for preparing a metallized foil, comprising: A multi-stage formation process is performed on the formed foil using a formation electrolyte containing nonionic surfactants, wherein the concentration of nonionic surfactants in the formation electrolyte varies in a gradient. Nonionic surfactants include polyoxyethylene ether compounds; In multi-stage formation electrolytes, the concentration gradient of nonionic surfactants decreases. The concentration of nonionic surfactant in the chemically synthesized electrolyte is 0.1 wt% to 1 wt%.

2. The method for preparing the electroformed foil according to claim 1, wherein, The electrolyte is an aqueous solution of adipate.

3. The method for preparing the electroformed foil according to claim 2, wherein, The electrolyte consists of an aqueous solution of ammonium adipate, with a concentration of 1 wt% to 20 wt%.

4. The method for preparing the electroformed foil according to claim 3, wherein, Multi-stage formation treatment of the formed foil is performed using a formation electrolyte containing nonionic surfactants, including: The formed foil is subjected to a primary formation treatment using a formation electrolyte composed of 1 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a primary formed foil. The primary formed foil is subjected to a secondary formed process using a forming electrolyte composed of 7 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a secondary formed foil. The secondary formed foil is subjected to a tertiary formation process using a formation electrolyte composed of 5 wt%~15 wt% ammonium adipate, 0.5 wt%~1 wt% polyoxyethylene ether compound and deionized water to obtain a tertiary formed foil. The three-stage formed foil is subjected to a four-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compound and deionized water to obtain a four-stage formed foil. The fourth-stage formed foil is subjected to a fifth-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 0.1 wt%~0.5 wt% polyoxyethylene ether compounds and deionized water to obtain a fifth-stage formed foil. The five-stage formed foil is subjected to a six-stage formation process using a formation electrolyte composed of 2 wt%~10 wt% ammonium adipate, 1 wt%~7 wt% phosphate, 0.1 wt%~0.5 wt% polyoxyethylene ether compound and deionized water to obtain a six-stage formed foil.

5. The method for preparing the electroformed foil according to claim 1, wherein, Also includes: Adjust the process parameters according to the reaction state of the formed foil.

6. The method for preparing the electroformed foil according to claim 1, wherein, Also includes: The formed foil that has undergone multi-stage formation processes undergoes at least one post-treatment, passivation, heat treatment, and drying process.

7. A chemically formed foil, said chemically formed foil being prepared by the chemically formed foil preparation method according to any one of claims 1 to 6.

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