High-performance shrinkage type aluminum electrolytic capacitor

Abstract

The utility model belongs to the technical field of aluminum electrolytic capacitors, and discloses a high-performance shrinkage type aluminum electrolytic capacitor, which comprises an anode foil and a cathode foil of the capacitor, first isolation paper is arranged between the anode foil and the cathode foil, second isolation paper is arranged on one side, far away from the anode foil, of the cathode foil, and the anode foil is made of sintered aluminum foil materials. Arc-shaped angle assemblies are arranged at four corners of the anode foil, and each arc-shaped angle assembly comprises a first arc-shaped angle, two second arc-shaped angles and two third arc-shaped angles. In the using process of the anode foil, aluminum powder particles on the surface of the anode foil are in a large number of irregular shapes, and the surface area of the aluminum foil is greatly increased. And on the premise that the capacity is kept unchanged, the volume of the capacitor can be reduced by 30%, so that the aim of body shrinkage is fulfilled. And meanwhile, a plurality of arc-shaped angles with different curvature radiuses are introduced into the corners of the anode foil to form gradual transition from a sharp angle to an arc, so that an electric field is prevented from being concentrated at the sharp angle.

Description

Technical Field

[0001] This utility model belongs to the field of aluminum electrolytic capacitor technology, specifically relating to a high-performance, miniaturized aluminum electrolytic capacitor. Background Technology

[0002] Aluminum electrolytic capacitors are a commonly used type of capacitor, widely used in electronic circuits, especially in power supply filtering, energy storage, and signal coupling. They are known for their high capacitance, low cost, and good frequency characteristics.

[0003] Application No. 202411310151.7 discloses an anode foil, a winding body, and an aluminum electrolytic capacitor for aluminum electrolytic capacitors. The invention states that "after the inventors unintentionally treated the anode foil with curved corners, i.e., the corners of the anode foil were set to curved corners, it effectively improved the flashover voltage when applied to aluminum electrolytic capacitors. Compared to long rectangular foils without curved corners, experimental verification showed that the flashover voltage was increased by more than 1.15 times; it effectively solved the technical defects in the traditional manufacturing process of aluminum electrolytic capacitors, effectively solved the mechanical properties of the anode foil's gradual bending during the unwinding process, reduced oxide film cracking, and improved the effective parallel voltage of the oxide film." While this solution effectively improved the flashover voltage and mechanical properties in the winding process, the capacitor's capacitance was not significantly increased. This means that, in the pursuit of capacitor miniaturization and high energy density, the overall reduction effect failed to meet expectations. Furthermore, the core of the curved corner design lies in the selection of the radius of curvature. If the radius of curvature is too small, the sharp-corner effect will still exist, and the electric field cannot be effectively dispersed, resulting in a negligible increase in flashover voltage. If the radius of curvature is too large, although the sharp-corner effect can be reduced, it may reduce the effective area of ​​the anode foil, thereby reducing the capacitance of the capacitor. Utility Model Content

[0004] The purpose of this invention is to provide a high-performance, miniaturized aluminum electrolytic capacitor to address the issues raised in the background art, such as the current overall miniaturization effect not meeting expectations under the trend of capacitor miniaturization and high energy density development, and the key to the arc-angle design being the selection of the radius of curvature, where an excessively large or small radius of curvature will produce negative effects.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a high-performance, miniaturized aluminum electrolytic capacitor, comprising: an anode foil and a cathode foil of the capacitor, wherein a first insulating paper is provided between the anode foil and the cathode foil, a second insulating paper is provided on the side of the cathode foil away from the anode foil, a core post is installed on one side of the anode foil, and the anode foil is made of sintered aluminum foil material;

[0006] The anode foil is provided with arc-shaped corner components at each of its four corners. The arc-shaped corner components include a first arc-shaped corner, two second arc-shaped corners and two third arc-shaped corners. The first arc-shaped corner is near the sharp corner, the two second arc-shaped corners are located on both sides of the first arc-shaped corner, and the two third arc-shaped corners are located on one side of the two second arc-shaped corners.

[0007] Preferably, the radii of curvature of the first arc angle, the second arc angle, and the third arc angle gradually increase, the first arc angle is connected to the second arc angle, and the third arc angle is connected to the second arc angle;

[0008] The anode foil, the first insulating paper, the cathode foil, and the second insulating paper are wound around the core column to form an aluminum electrolytic capacitor winding body, and the output end of the winding body is equipped with a lead wire.

[0009] The aluminum electrolytic capacitor is fitted with a housing outside its windings, and the leads extend to the outside of the housing. The main function of the housing is to protect the internal structure of the capacitor, including the anode foil, cathode foil, insulating paper, and electrolyte. The leads serve as current conduction channels between the capacitor and the external circuit, ensuring that charge can efficiently enter and exit the capacitor.

[0010] Through the above technical solution:

[0011] In use, the anode foil is the main charge storage medium of the capacitor. According to the structural principle of capacitors, when the plate area A in the formula increases significantly, the capacitance C of the capacitor will also increase significantly. Sintered aluminum foil is a material formed by sintering aluminum powder onto the surface of aluminum foil at high temperature. Compared to traditional aluminum foil, sintered foil not only retains the surface area of ​​the aluminum foil's pores, but also provides a large number of irregular shapes from the aluminum powder particles on the foil surface, increasing the surface area of ​​the aluminum foil. Tests have shown that using sintered aluminum foil as the anode foil material can effectively increase the specific capacitance by about 30% for the same volume. Due to the increased specific capacitance, the capacitance C of the capacitor also increases by 30%. Under the premise of unchanged capacitance, the volume of the capacitor can be reduced by 30%, thus achieving the ultimate goal of miniaturization.

[0012] In aluminum electrolytic capacitors, the design of the anode foil is crucial. The multi-stage curved corner design is significant in improving the performance and reliability of aluminum electrolytic capacitors. The first curved corner, near the sharp corner, has a small radius of curvature. Its main function is to initially disperse the electric field and reduce the sharp corner effect. The second curved corner has a gradually increasing radius of curvature, further dispersing the electric field and making its distribution more uniform. The third curved corner has the largest radius of curvature, ensuring that the electric field is completely dispersed at the corners of the anode foil, eliminating any potential tip discharge. The design concept of the multi-stage curved corner is to introduce multiple curved corners with different radii of curvature at the corners of the anode foil, thus forming a gradual transition from sharp corners to rounded arcs. This gradual structure effectively disperses the electric field, avoiding concentration at sharp corners. The multi-stage curved corner design significantly reduces the sharp corner effect at the corners of the anode foil, thereby reducing the risk of tip discharge. Tip discharge is one of the main causes of early failure in aluminum electrolytic capacitors, and the multi-stage curved corner design effectively solves this problem. Because the electric field is dispersed and tip discharge is reduced, damage to the oxide film on the anode foil surface is also reduced, decreasing cracking and breakage on the anode foil surface, thereby extending the capacitor's service life. In summary, the multi-stage arc-angle design, by cleverly dispersing the electric field and reducing the risk of tip discharge, provides a strong guarantee for improving the performance and reliability of aluminum electrolytic capacitors.

[0013] The cathode foil surface is coated with a multilayer composite material, which includes a metal layer and a carbon-based material layer.

[0014] Through the above technical solution:

[0015] In operation, a metal layer and a carbon-based material layer are sequentially coated onto the surface of the cathode foil. The metal layer is typically composed of highly conductive metals such as copper, silver, and nickel. Because these metals have higher conductivity than aluminum, they significantly reduce the equivalent series resistance (ESR) of the cathode foil. Lowering the ESR reduces energy loss in the capacitor, improves charging and discharging efficiency, and enhances its frequency characteristics, resulting in superior performance in high-frequency applications. The carbon-based material layer is typically composed of carbon-based materials such as graphene and carbon nanotubes. These materials possess excellent conductivity and chemical stability, further reducing the resistance of the cathode foil. The high specific surface area of ​​carbon-based materials provides more conductive paths, further reducing contact resistance. The chemical stability of carbon-based materials improves the corrosion resistance of the cathode foil, thereby extending the capacitor's lifespan. This multi-layer coating structure improves the reliability and lifespan of the capacitor. The mechanical strength and chemical stability of the metal layer and carbon-based materials reduce mechanical damage and material aging, improving the capacitor's reliability and lifespan, thus reducing maintenance costs and replacement frequency.

[0016] Both the first and second release papers are wavy in shape, and the wavy release paper is easily compressed when it is wound. In a capacitor of the same volume, the wavy release paper can hold more electrolyte and electrode material, thereby increasing the energy density of the capacitor.

[0017] Through the above technical solution:

[0018] In use, the wavy design of the first and second insulating papers increases the contact area between the electrolyte and the anode and cathode foils. The wavy structure allows the electrolyte to penetrate more fully into the electrode surfaces, thereby increasing the effective area for the electrochemical reaction. A larger contact area is beneficial for improving the capacitor's capacitance and charge / discharge efficiency. The wavy first and second insulating papers not only increase the contact area between the electrolyte and electrodes but also form a more effective insulating layer between the electrodes. The wavy structure reduces direct contact between electrodes, thus reducing the risk of short circuits. Effective isolation improves the reliability and safety of the capacitor. The wavy structure of the first and second insulating papers creates microchannels, promoting electrolyte flow between the electrodes. This enhanced fluidity helps the electrolyte to distribute more evenly during charge and discharge. Uniform electrolyte distribution reduces local electrolyte depletion and concentration gradients, thereby improving the capacitor's stability and lifespan.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] (1) This utility model uses an anode foil made of sintered aluminum powder foil to achieve the miniaturization of the capacitor. During use, the aluminum powder particles on the surface of the aluminum foil are in a large number of irregular shapes, which greatly increases the surface area of ​​the aluminum foil. Tests have shown that when sintered aluminum foil is used as the anode foil material of the capacitor, the specific capacitance of the anode foil can be effectively increased by about 30% under the same volume. Under the premise that the capacitance remains unchanged, the volume of the capacitor can be reduced by 30%, thereby achieving the purpose of miniaturization.

[0021] (2) This utility model introduces multiple arc-shaped corners with different radii of curvature at the corners of the anode foil, thereby forming a gradual transition from sharp corners to arcs. This gradual structure can effectively disperse the electric field, avoid the concentration of the electric field at the sharp corners, reduce the cracking and damage on the surface of the anode foil, and thus extend the service life of the capacitor. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is an appearance drawing of the present utility model;

[0024] Figure 3 This is a schematic diagram of the core post structure of this utility model;

[0025] Figure 4 This is a schematic diagram of the structure of the anode foil of this utility model;

[0026] Figure 5 This is a schematic diagram of the structure of the cathode foil of this utility model;

[0027] Figure 6 This is a schematic diagram of the structure of the second release paper of this utility model;

[0028] Figure 7 for Figure 5 Enlarged view of part A in the image;

[0029] In the figure: 1. Anode foil; 2. Cathode foil; 3. First insulating paper; 4. Second insulating paper; 5. Core post; 6. Lead wire; 7. First arc angle; 8. Second arc angle; 9. Third arc angle; 10. Metal layer; 11. Carbon-based material layer; 12. Shell. Detailed Implementation

[0030] 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.

[0031] Please see Figures 1-6 As shown, the present invention provides the following technical solution: a high-performance miniaturized aluminum electrolytic capacitor, comprising: an anode foil 1 and a cathode foil 2 of the capacitor, a first insulating paper 3 between the anode foil 1 and the cathode foil 2, a second insulating paper 4 on the side of the cathode foil 2 away from the anode foil 1, a core post 5 installed on one side of the anode foil 1, and the anode foil 1 being made of sintered aluminum foil material.

[0032] The anode foil 1 is provided with arc-shaped corner components at all four corners. The arc-shaped corner components include a first arc-shaped corner 7, two second arc-shaped corners 8 and two third arc-shaped corners 9. The first arc-shaped corner 7 is near the sharp corner, the two second arc-shaped corners 8 are located on both sides of the first arc-shaped corner 7, and the two third arc-shaped corners 9 are located on one side of the two second arc-shaped corners 8.

[0033] Furthermore, the radii of curvature of the first arc angle 7, the second arc angle 8, and the third arc angle 9 gradually increase, with the first arc angle 7 connected to the second arc angle 8, and the third arc angle 9 connected to the second arc angle 8.

[0034] Anode foil 1, first insulating paper 3, cathode foil 2 and second insulating paper 4 are wound around core column 5 to form an aluminum electrolytic capacitor winding body, and lead wire 6 is installed at the output end of the winding body;

[0035] The aluminum electrolytic capacitor has a housing 12 mounted outside the winding body, and leads 6 extend to the outside of the housing 12. The main function of the housing 12 is to protect the internal structure of the capacitor, including the anode foil 1, cathode foil 2, insulating paper, and electrolyte. The leads 6 are the current conduction channels between the capacitor and the external circuit, ensuring that charge can enter and exit the capacitor efficiently.

[0036] Through the above technical solution:

[0037] In use, the anode foil 1 is the main charge storage medium of the capacitor. According to the structural principle of capacitors, when the plate area A in the formula increases significantly, the capacitance C of the capacitor will also increase significantly. Sintered aluminum foil is a material formed by sintering aluminum powder onto the surface of aluminum foil at high temperature. Compared to traditional aluminum foil, sintered foil not only retains the surface area of ​​the aluminum foil's pores, but also provides a large number of irregular shapes from the aluminum powder particles on the foil surface, increasing the surface area of ​​the aluminum foil. Tests have shown that using sintered aluminum foil as the anode foil 1 material can effectively increase the specific capacitance by approximately 30% for the same volume. Due to the increased specific capacitance, the capacitance C of the capacitor also increases by 30%. Under the premise of unchanged capacitance, the volume of the capacitor can be reduced by 30%, thus achieving the ultimate goal of miniaturization.

[0038] In aluminum electrolytic capacitors, the design of the anode foil 1 is crucial. The multi-stage arc-shaped corner design is significant in improving the performance and reliability of aluminum electrolytic capacitors. The first arc-shaped corner 7, located near the sharp corner, has a small radius of curvature. Its main function is to initially disperse the electric field and reduce the sharp-corner effect. The second arc-shaped corner 8 gradually increases in radius of curvature, further dispersing the electric field and making its distribution more uniform. The third arc-shaped corner 9 has the largest radius of curvature, ensuring that the electric field is completely dispersed at the corners of the anode foil 1, eliminating any potential tip discharge. The design concept of the multi-stage arc-shaped corner is to introduce multiple arc-shaped corners with different radii of curvature at the corners of the anode foil 1, thus forming a gradual transition from sharp corners to rounded arcs. This gradual structure effectively disperses the electric field, avoiding concentration at sharp corners. The multi-stage arc-shaped corner design significantly reduces the sharp-corner effect at the corners of the anode foil 1, thereby reducing the risk of tip discharge. Tip discharge is one of the main causes of early failure in aluminum electrolytic capacitors, and the multi-stage arc-shaped corner design effectively solves this problem. Because the electric field is dispersed and tip discharge is reduced, damage to the oxide film on the surface of anode foil 1 is also reduced, thus minimizing cracking and breakage on the surface of anode foil 1 and extending the service life of the capacitor. In summary, the multi-stage arc-angle design, by cleverly dispersing the electric field and reducing the risk of tip discharge, provides a strong guarantee for improving the performance and reliability of aluminum electrolytic capacitors.

[0039] Please see Figures 1-7As shown, the cathode foil 2 is coated with a multilayer composite material, which includes a metal layer 10 and a carbon-based material layer 11.

[0040] Through the above technical solution:

[0041] In use, a metal layer 10 and a carbon-based material layer 11 are sequentially coated onto the surface of the cathode foil 2. The metal layer 10 is typically composed of highly conductive metals such as copper, silver, and nickel. Because these metals have higher conductivity than aluminum, they can significantly reduce the equivalent series resistance (ESR) of the cathode foil 2. Lowering the ESR reduces energy loss in the capacitor, improves charging and discharging efficiency, and enhances its frequency characteristics, making the capacitor perform better in high-frequency applications. The carbon-based material layer 11 is typically composed of carbon-based materials such as graphene and carbon nanotubes. These materials have excellent conductivity and chemical stability, further reducing the resistance of the cathode foil 2. The high specific surface area of ​​carbon-based materials provides more conductive paths, further reducing contact resistance. The chemical stability of carbon-based materials improves the corrosion resistance of the cathode foil 2, thereby extending the capacitor's lifespan. The multi-layer coating structure improves the reliability and lifespan of the capacitor. The mechanical strength and chemical stability of the metal layer 10 and the carbon-based material reduce mechanical damage and material aging, improving the reliability and lifespan of the capacitor, thereby reducing maintenance costs and replacement frequency.

[0042] Please see Figure 1 , Figure 3 and Figure 6 As shown, the first release paper 3 and the second release paper 4 are both wavy in shape. The wavy release paper is easily compressed when it is wound. In a capacitor of the same volume, the wavy release paper can hold more electrolyte and electrode material, thereby increasing the energy density of the capacitor.

[0043] Through the above technical solution:

[0044] In use, the wavy design of the first and second insulating papers 3 and 4 increases the contact area between the electrolyte and the anode foil 1 and cathode foil 2. The wavy structure allows the electrolyte to penetrate more fully into the electrode surface, thereby increasing the effective area for the electrochemical reaction. A larger contact area is beneficial for improving the capacitor's capacitance and charge / discharge efficiency. The wavy first and second insulating papers 3 and 4 not only increase the contact area between the electrolyte and the electrodes but also form a more effective insulating layer between the electrodes. The wavy structure reduces direct contact between the electrodes, thus reducing the risk of short circuits. Effective isolation improves the reliability and safety of the capacitor. The wavy structure of the first and second insulating papers 3 and 4 forms microchannels, promoting the flow of electrolyte between the electrodes. This enhanced fluidity helps the electrolyte to distribute more evenly during charge and discharge. Uniform electrolyte distribution reduces local electrolyte depletion and concentration gradients, thereby improving the capacitor's stability and lifespan.

[0045] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high performance miniaturized aluminum electrolytic capacitor, characterized by, Include: The anode foil (1) and cathode foil (2) of the capacitor, the first isolation paper (3) is arranged between the anode foil (1) and cathode foil (2), the second isolation paper (4) is arranged on the side of the cathode foil (2) away from the anode foil (1), the core column (5) is installed on the side of the anode foil (1), and the anode foil (1) is made of sintered aluminum foil material; The anode foil (1) is provided with an arc-shaped corner assembly at each corner, the arc-shaped corner assembly comprises a first arc-shaped corner (7), two second arc-shaped corners (8) and two third arc-shaped corners (9), the first arc-shaped corner (7) is close to the sharp corner, the two second arc-shaped corners (8) are respectively located on the two sides of the first arc-shaped corner (7), and the two third arc-shaped corners (9) are respectively located on the side of the two second arc-shaped corners (8).

2. The high performance miniaturized aluminum electrolytic capacitor according to claim 1, characterized in that: The curvature radius of the first arc-shaped corner (7), the second arc-shaped corner (8) and the third arc-shaped corner (9) gradually increases, the first arc-shaped corner (7) is connected with the second arc-shaped corner (8), and the third arc-shaped corner (9) is connected with the second arc-shaped corner (8).

3. The high performance miniaturized aluminum electrolytic capacitor of claim 1 wherein: The surface of the cathode foil (2) is coated with a multilayer composite material, and the multilayer composite material comprises a metal layer (10) and a carbon-based material layer (11).

4. The high performance miniaturized aluminum electrolytic capacitor of claim 1 wherein: The shape of the first isolation paper (3) and the second isolation paper (4) is "wavy".

5. The high performance miniaturized aluminum electrolytic capacitor of claim 1 wherein: The anode foil (1), the first isolation paper (3), the cathode foil (2) and the second isolation paper (4) are wound around the core column (5) to form an aluminum electrolytic capacitor winding body, and the output end of the winding body is provided with a lead piece (6).

6. A high performance miniaturized aluminum electrolytic capacitor according to claim 5, characterized in that: The aluminum electrolytic capacitor winding body is externally provided with a shell (12), and the lead piece (6) extends to the outside of the shell (12).

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