An electrode plate for producing anode foil for aluminum electrolytic capacitors.

Abstract

This utility model relates to the field of anode foil production technology and discloses an electrode plate for producing anode foil for aluminum electrolytic capacitors. It includes a formation tank with multiple sets of guide rollers arranged side-by-side on the inner side of the formation tank for transporting the anode foil to be processed. Cathode plates are arranged on both outer sides of the anode foil for chemical processing. The top and bottom of the cathode plates are a non-working surface and a functional working surface, respectively. The bottom of the functional working surface has multiple asymmetrical protrusions extending in a predetermined direction, which are asymmetrical serrated structures. In this utility model, by setting a gas guiding slope to actively guide the bubbles to detach, electric field shielding is eliminated, ensuring a uniform oxide film. Simultaneously, its integrated microchannel active circulation system solves the mass transfer and heat dissipation problems in high-speed production, ultimately significantly improving production efficiency while enhancing product consistency.

Description

Technical Field

[0001] This utility model relates to the field of anode foil production technology, and in particular to an electrode plate for producing anode foil for aluminum electrolytic capacitors. Background Technology

[0002] Currently, aluminum electrolytic capacitors play an indispensable role in consumer electronics, industrial control, and new energy fields due to their advantages such as large capacitance per unit volume and relatively low cost. One of the core components of aluminum electrolytic capacitors is the anode foil, and the quality of the alumina dielectric film formed on its surface directly determines key performance indicators such as leakage current, withstand voltage, loss angle, and service life. The production of anode foil typically involves two core processes: etching and formation. The formation process involves applying voltage in a specific electrolyte environment to form a dense alumina insulating layer on the surface of the etched foil. The electrode plate (as the cathode) used in this process is a key piece of equipment to ensure the quality of formation.

[0003] Regarding the aforementioned aspects, in existing anode foil production lines, the formation process is typically carried out continuously in a long, narrow formation tank. The anode foil to be processed is guided by a guide roller system, passing at a uniform speed through the tank filled with electrolyte. On both sides of the anode foil, parallel electrode plates serving as cathodes are placed. These electrode plates have a relatively simple structure, mostly flat or mesh-like metal plates, and their main function is to form a complete electrochemical circuit with the anode foil. When an external power source applies a voltage between the anode foil and the cathode plate, current flows through the electrolyte, causing an oxidation reaction on the surface of the anode foil, thereby generating the desired dielectric film. Throughout the process, the replenishment and renewal of the electrolyte mainly rely on natural convection and diffusion.

[0004] However, in practical production applications, the above-mentioned technical solutions have inherent defects that are difficult to overcome. First, the formation reaction on the cathode plate surface is inevitably accompanied by hydrogen evolution side reactions, generating a large number of hydrogen bubbles. These bubbles are electrically insulating and randomly adsorb onto the flat cathode plate surface. This irregular bubble adhesion behavior directly causes the electric field behind them to be shielded, resulting in a sharp decrease in the electric field strength in the corresponding area on the anode foil. This leads to inconsistent growth rates of the oxide film, forming defects of uneven thickness, which degrades the leakage current performance of the final product and makes it difficult to guarantee reliability. Second, with the industry's increasing demands for production efficiency, the foil feeding speed of the anode foil is getting faster and faster. High-speed production consumes a huge amount of electrolyte in the narrow gap between the anode foil and the cathode plate. The replenishment rate of ions cannot keep up with the consumption rate, which directly causes uneven local electrolyte concentration. At the same time, a large amount of Joule heat generated by the violent electrochemical reaction accumulates rapidly here, leading to local temperature runaway. Fluctuations in concentration and temperature seriously affect the stability of film quality.

[0005] To address the above problems, an electrode plate for the production of anode foil for aluminum electrolytic capacitors is proposed. Utility Model Content

[0006] To overcome the above shortcomings, this utility model provides an electrode plate for the production of anode foil for aluminum electrolytic capacitors, aiming to solve the problem that an existing electrode plate for the production of anode foil for aluminum electrolytic capacitors is prone to generating a bubble shielding effect during the formation process, resulting in poor product quality consistency and difficulty in meeting the requirements of high-speed production.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an electrode plate for producing anode foil for aluminum electrolytic capacitors, comprising a formation tank, a controller being provided at the front end of the formation tank, an oxidation reaction control box being provided inside the controller, multiple sets of guide rollers being arranged side by side on the inner side of the formation tank, the multiple sets of guide rollers being used to transport the anode foil to be processed, and cathode plates being provided on both outer sides of the anode foil, the cathode plates being used to chemically process the anode foil.

[0008] As a further description of the above technical solution:

[0009] The top and bottom of the cathode plate are a non-working surface and a functional working surface, respectively. The bottom of the functional working surface is provided with a plurality of asymmetrical protrusions extending in a preset direction.

[0010] As a further description of the above technical solution:

[0011] The protruding structure is an asymmetrical sawtooth structure, and the protruding structure is provided with a gentle slope and a steep facade.

[0012] As a further description of the above technical solution:

[0013] The functional working surface is provided with multiple microchannels inside, which are used to guide the electrolyte to flow through the functional working surface.

[0014] As a further description of the above technical solution:

[0015] The protruding structure includes crests and troughs, and the microchannel is disposed at the trough of the protruding structure. The extension direction of the microchannel is perpendicular to the extension direction of the protruding structure.

[0016] As a further description of the above technical solution:

[0017] An electrolyte chamber is provided inside the non-working surface. The electrolyte chamber is used to contain and distribute electrolyte. The electrolyte chamber is connected to an electrolyte tank through a delivery pipe. The electrolyte tank is located on the right side of the formation tank.

[0018] As a further description of the above technical solution:

[0019] The electrolyte chamber is connected to multiple microchannels of the functional working surface to form an internal flow path for electrolyte circulation.

[0020] As a further description of the above technical solution:

[0021] The bottom of the formation tank is provided with support columns at all four corners, and a liquid outlet pipe is installed on the right side of the formation tank.

[0022] This utility model has the following beneficial effects:

[0023] 1. This invention solves the problem of shielding and interfering with the electric field by bubbles generated during the hydrogen evolution reaction at the cathode, thereby ensuring the ultimate uniformity of the dielectric oxide film on the anode foil. On traditional planar electrodes, the random attachment and detachment of hydrogen bubbles can cause drastic fluctuations in the electric field intensity of the corresponding area of ​​the anode foil, forming weak points in the oxide film. However, the gas guiding slope provides a pre-set, low-resistance discharge path for each bubble, allowing it to be actively guided and orderly removed from the reaction interface after its generation.

[0024] 2. In this invention, through microchannel array and active circulating spraying, the narrow reaction gap between the anode foil and the cathode plate is transformed from a "dead zone" where ions are replenished by diffusion into an "active microreactor" where the electrolyte composition and temperature are constantly forced to be homogenized. This completely solves the problem of reduced formation quality caused by uneven ion consumption and local overheating in high-speed production, and can significantly increase the production speed of anode foil and shorten the formation time. Attached Figure Description

[0025] Figure 1 This is a three-dimensional schematic diagram of an electrode plate for producing anode foil for aluminum electrolytic capacitors according to the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the guide roller for the production of anode foil for aluminum electrolytic capacitors according to this utility model.

[0027] Figure 3 This is a schematic diagram of the non-working surface of an electrode plate used in the production of anode foil for aluminum electrolytic capacitors according to this utility model.

[0028] Figure 4 This is a schematic diagram of the functional working surface of an electrode plate for producing anode foil for aluminum electrolytic capacitors, as proposed in this utility model.

[0029] Legend:

[0030] 1. Formation tank; 101. Support column; 102. Discharge pipe; 2. Controller; 3. Oxidation reaction control box; 4. Electrolyte tank; 5. Guide roller; 6. Cathode plate; 601. Non-working surface; 602. Electrolyte chamber; 603. Functional working surface; 604. Microchannel; 605. Slope; 606. Steep vertical surface; 7. Infusion pipe. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Reference Figure 1 - Figure 4 This utility model provides an embodiment of an electrode plate for producing anode foil for aluminum electrolytic capacitors, comprising a formation tank 1. Support columns 101 for support and stability are provided at the four corners of the bottom of the formation tank 1. An outlet pipe 102 for discharging waste liquid and circulating liquid is installed on the right side of the formation tank 1. A controller 2 is provided at the front exterior of the formation tank 1, and an oxidation reaction control box 3 for precisely controlling process parameters such as formation voltage and current is integrated inside the controller 2. Inside the formation tank 1, multiple sets of guide rollers 5 are arranged side-by-side along the anode foil's travel direction. These guide rollers 5 together form a conveying system for smoothly and uniformly conveying the anode foil to be processed through the tank. On both sides of the anode foil's conveying path, adjacent to its surface, are cathode plates 6, the core component of this solution. These cathode plates 6 act as the cathode for the electrochemical reaction, working together with the anode foil as the anode to generate an oxide film on its surface. Specifically, the functional working surface 603 of the cathode plate 6 is cleverly equipped with multiple asymmetrical protrusions extending along a predetermined direction. These protrusions are asymmetrical serrated, each consisting of a gently sloping ramp 605 and a steeply sloping face 606. During the formation process, hydrogen bubbles generated on the cathode, under buoyancy, preferentially slide and accumulate along the gently sloping ramp 605, forming a predetermined, low-resistance discharge path. This allows the bubbles to be actively and orderly guided away from the reaction interface after formation. This effectively solves the shielding and interference caused by random bubble attachment to the electric field, ensuring the extreme uniformity of the oxide film. Consequently, the leakage current of the final anode foil is significantly reduced, the withstand voltage is more consistent, and the reliability and lifespan of the capacitor are greatly improved.

[0033] Reference Figure 3 - Figure 4On the functional working surface 603 of the cathode plate 6, multiple microchannels 604 are machined along a direction perpendicular to the extension direction of the protruding structure. These microchannels 604 are specifically located at the troughs of the sawtooth-shaped protrusions, serving as outlets for fresh electrolyte and guiding the electrolyte to flow evenly across the entire functional working surface 603. To supply electrolyte to these microchannels 604, an electrolyte chamber 602 for containing and distributing electrolyte is provided inside the non-working surface 601 of the cathode plate 6 away from the anode foil. This electrolyte chamber 602 is connected to a large-capacity electrolyte tank 4 located on the right side of the formation tank 1 via an external infusion pipe 7. During operation, fresh, temperature-controlled electrolyte is pumped from the electrolyte tank 4, enters the electrolyte chamber 602 through the infusion pipe 7 for distribution, and is then actively and evenly sprayed into the narrow reaction gap between the anode foil and the cathode plate via the interconnected microchannels 604. This active circulating injection mechanism transforms the reaction zone, which originally relied on passive ion diffusion, into an active microreactor where the electrolyte composition and temperature are constantly forced to be homogenized, thus completely solving the problem of declining formation quality caused by uneven local ion consumption and heat accumulation during high-speed production.

[0034] Working principle: After the oxidation reaction control box 3 in the controller 2 is started, multiple sets of guide rollers 5 arranged side by side inside the formation tank 1 begin to rotate, driving the anode foil to be processed to enter from one end of the formation tank 1 in a horizontal posture and move at a constant speed to the other end. At the same time, the electrolyte in the electrolyte tank 4 located on the right side of the formation tank 1 is pumped into the electrolyte chamber 602 inside the non-working surface 601 of the cathode plate 6 located on both sides of the anode foil through the liquid delivery pipe 7. After the electrolyte is distributed in the electrolyte chamber 602, it enters multiple microchannels 604 located inside the functional working surface 603, which are connected to it, and finally flows out from the microchannels 604 located at the trough of the raised structure and is injected into the reaction gap between the functional working surface 603 and the surface of the anode foil. At this time, the oxidation reaction control box 3 applies voltage between the anode foil and the cathode plate 6. Current flows through the electrolyte between the functional working surface 603 and the anode foil, and chemical processing occurs on the surface of the anode foil. The asymmetric sawtooth protrusion structure at the bottom of the functional working surface 603 is composed of a ramp 605 and a steep vertical surface 606. Its extension direction is perpendicular to the extension direction of the microchannel 604. The gas generated in this process is discharged from both sides of the functional working surface 603.

[0035] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electrode plate for the production of anode foils for aluminum electrolytic capacitors, comprising a formation tank (1), characterized in that: A controller (2) is provided at the front end of the formation tank (1). An oxidation reaction control box (3) is provided inside the controller (2). Multiple sets of guide rollers (5) are arranged side by side on the inner side of the formation tank (1). The multiple sets of guide rollers (5) are used to transport the anode foil to be processed. Cathode plates (6) are provided on both sides of the outer side of the anode foil. The cathode plates (6) are used to chemically process the anode foil.

2. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 1, characterized by: The top and bottom of the cathode plate (6) are a non-working surface (601) and a functional working surface (603), respectively. The bottom of the functional working surface (603) is provided with a plurality of asymmetrical protrusions extending in a preset direction.

3. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 2, characterized by: The protruding structure is an asymmetrical sawtooth structure, and the protruding structure is provided with a gentle slope (605) and a steep facade (606) with a steep angle.

4. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 2, characterized by: The functional working surface (603) is provided with a plurality of microchannels (604) inside, which are used to guide the electrolyte to flow through the functional working surface (603).

5. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 4, characterized by: The protruding structure includes crests and troughs, and the microchannel (604) is disposed at the trough of the protruding structure. The extension direction of the microchannel (604) is perpendicular to the extension direction of the protruding structure.

6. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 2, characterized by: An electrolyte chamber (602) is provided inside the non-working surface (601). The electrolyte chamber (602) is used to contain and distribute electrolyte. The electrolyte chamber (602) is connected to an electrolyte tank (4) through a delivery pipe (7). The electrolyte tank (4) is located on the right side of the formation tank (1).

7. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 6, characterized by: The electrolyte chamber (602) is connected to multiple microchannels (604) of the functional working surface (603) to form an internal flow path for electrolyte circulation.

8. The electrode plate for producing an anode foil for an aluminum electrolytic capacitor according to claim 1, characterized by: The bottom four corners of the formation tank (1) are provided with support columns (101), and the right side of the formation tank (1) is provided with a liquid outlet pipe (102).

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