Core Package, Aluminum Electrolytic Capacitor, and Sealing Method Thereof

Abstract

The present disclosure provides a core package, an aluminum electrolytic capacitor, and a method for sealing the same. The core package includes a plurality of first electrode foils and a plurality of second electrode foils arranged in a stacked manner. The first electrode foil is either an anode foil or a cathode foil, and the second electrode foil is the other of the anode foil and the cathode foil. Among the plurality of first electrode foils, one first conductive foil piece is provided at the edge of each first electrode foil. A first portion of the first conductive foil piece is electrically connected to the corresponding first electrode foil, and a second portion of the first conductive foil piece extends and protrudes with respect to the first electrode foil. The plurality of first conductive foil pieces are all connected to one first conductive foil strip via the second portions. Here, an oxide film is formed on the surface of the first conductive foil piece.

Description

Technical Field

[0001] This application is based on a Chinese patent application with an application number of 202210904879.7 and a filing date of July 29, 2022, and claims the priority of this Chinese patent application. All the contents of this Chinese patent application are incorporated herein by reference.

[0002] The present disclosure relates to the technical field of capacitors, and particularly to a core package, an aluminum electrolytic capacitor, and a sealing method thereof.

Background Art

[0003] Conventional aluminum electrolytic capacitors often adopt a wound core package. After impregnation, components such as an aluminum case and a rubber stopper are assembled and formed. With the miniaturization and flattening of electronic products, the conventional cylindrical aluminum electrolytic capacitors have no advantage in space utilization rate, restricting the development trend of miniaturization and flattening of electronic products. Based on the application limitations of cylindrical aluminum electrolytic capacitors, rectangular aluminum electrolytic capacitors have already been developed in the market, which can effectively meet the requirements of miniaturization and flattening of electronic products. However, the capacitance extraction structure of the anode foil and cathode foil arranged in layers in the current rectangular aluminum electrolytic capacitor cannot guarantee the performance of the aluminum electrolytic capacitor. For example, due to the characteristics of the anode foil material, it is difficult to directly connect the conductive foil strip for capacitance extraction in the prior art to the anode foil, damaging the structure of the anode foil. Also, for example, there is a problem that current concentrates at the connection point between the conductive foil strip and the anode foil, generating heat. All of the above have the problem that the performance of the aluminum electrolytic capacitor cannot be guaranteed.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The objective of the present disclosure is to provide a core package, an aluminum electrolytic capacitor, and a sealing method thereof to solve the problem that the performance of an aluminum electrolytic capacitor cannot be guaranteed in the capacitance extraction structure of a rectangular aluminum electrolytic capacitor in the prior art.

Means for Solving the Problem

[0005] One embodiment of the present disclosure provides a core package including a plurality of first electrode foils and a plurality of second electrode foils arranged in a stacked manner. One of the second electrode foils is interposed between two adjacent first electrode foils, one of the first electrode foils is interposed between two adjacent second electrode foils, and electrolytic paper is interposed between the adjacent first electrode foil and the second electrode foil. The first electrode foil is either an anode foil or a cathode foil, and the second electrode foil is the other of the anode foil and the cathode foil. One first conductive foil piece is provided at the edge of each of the plurality of first electrode foils. The first portion of the first conductive foil piece is electrically connected to the corresponding first electrode foil, and the second portion of the first conductive foil piece extends and protrudes with respect to the first electrode foil. The plurality of first conductive foil pieces are all connected to one first conductive foil strip through the second portion. Here, an oxide film is formed on the surface of the first conductive foil piece.

[0006] Optionally, in the core package, one second conductive foil piece is provided at the edge of each of the plurality of second electrode foils. The first portion of the second conductive foil piece is electrically connected to the corresponding second electrode foil, and the second portion of the second conductive foil piece extends and protrudes with respect to the second electrode foil. The plurality of second conductive foil pieces are connected to one second conductive foil strip through the second portion. Here, an oxide film is formed on the surface of the second conductive foil piece.

[0007] Optionally, in the core package, the first conductive foil piece is made of a pure aluminum material, and the characteristics of the oxide film on the surface of the first conductive foil piece are the same as those of the oxide film on the surface of the first electrode foil.

[0008] Optionally, in the core package, the oxide film is formed on the surface of the first conductive foil piece through a formation process treatment, and the formation process treatment method for forming the oxide film on the surface of the first conductive foil piece is the same as the formation process treatment method for forming the oxide film on the surface of the first electrode foil.

[0009] Optionally, in the core package, the first electrode foil is an anode foil, the second electrode foil is a cathode foil, each of the cathode foils includes an integrally formed body portion and a tab portion, the tab portion protrudes with respect to the edge of the body portion, and a plurality of the cathode foils are connected to a single third conductive foil strip via the tab portion.

[0010] Optionally, in the core package, each of the first electrode foils includes an integrally formed body portion and a tab portion, the tab portion protrudes with respect to the edge of the body portion, a first portion of the first conductive foil piece is connected to the first electrode foil via the tab portion, and here, the tab portions of a plurality of the first electrode foils are sequentially arranged alternately along a first direction.

[0011] Optionally, in the core package, a plurality of the first conductive foil pieces are arranged side by side in order along the first direction, and second portions of two adjacent first conductive foil pieces are adhesively connected.

[0012] Optionally, in the core package, the thickness of the first conductive foil piece is 5 to 50 μm.

[0013] Optionally, in the core package, between the first portion of the first conductive foil piece and the first electrode foil, they are connected by one of riveting, welding, and a conductive adhesive.

[0014] One embodiment of the present disclosure further provides an aluminum electrolytic capacitor including the core package described in any one of the above items.

[0015] Optionally, in the aluminum electrolytic capacitor, it further includes a first case with one end open and made of an aluminum material, the core package is provided inside the first case, a first sealing cover plate is provided at the opening, terminals are provided on the first sealing cover plate, and the first conductive foil strip is connected to the terminals on the first sealing cover plate.

[0016] Optionally, in the aluminum electrolytic capacitor, the dimensions and shape of the first case are adapted to the dimensions and shape of the core package.

[0017] Optionally, in the aluminum electrolytic capacitor, it further includes a sealing bag made of an aluminum-plastic film. The sealing bag has its edges sealed to form a receiving chamber for sealing the core package inside the sealing bag, and the first conductive foil strip extends outside the sealing bag through the first sealing edge of the sealing bag.

[0018] Optionally, in the aluminum electrolytic capacitor, it further includes a second case with one end open. The sealing bag containing the core package is provided inside the second case, a second sealing cover plate is provided at the opening, terminals are provided on the second sealing cover plate, and the first conductive foil strip is connected to the terminals on the second sealing cover plate.

[0019] Optionally, in the aluminum electrolytic capacitor, it further includes an integrally formed second case. The sealing bag is provided inside the second case, the first conductive foil strip projects outside the second case, and the space between the first conductive foil strip and the second case is sealed and insulated.

[0020] Optionally, in the aluminum electrolytic capacitor, the sealing bag further includes an airbag structure with a separation zone interposed between the airbag structure and the accommodation chamber, and an exhaust structure communicating the airbag structure with the accommodation chamber is provided in the separation zone. Inside the second case, the airbag structure is provided on one side of the accommodation chamber. Here, the direction from the accommodation chamber to the airbag structure is the stacking direction of the plurality of first electrode foils and the plurality of second electrode foils.

[0021] Optionally, in the aluminum electrolytic capacitor, a pressing clamp for sandwiching the accommodation chamber is further provided inside the second case, and the airbag structure is located on one side of the pressing clamp.

[0022] Optionally, in the aluminum electrolytic capacitor, the separation zone faces the first sealing edge of the sealing bag or is located on the side adjacent to the first sealing edge.

[0023] Optionally, in the aluminum electrolytic capacitor, the width of the second sealing edge of the sealing bag is larger than the width of the first sealing edge, and here, the second sealing edge is located on both sides of the first sealing edge.

[0024] Optionally, in the aluminum electrolytic capacitor, the second sealing edge includes at least two sealing separation zones.

[0025] One embodiment of the present disclosure further provides a sealing method applicable to the above aluminum electrolytic capacitor. The method includes arranging a core package in an accommodation chamber of a sealing bag made of an aluminum plastic film so that a first conductive foil strip of the core package penetrates through an opening of the sealing bag, heat-sealing the sealing bag at the opening to form a first sealing edge, and heat-sealing a connection colloid on the first conductive foil strip to the sealing bag.

[0026] Optionally, in the above sealing method, the sealing bag further includes an airbag structure with a sealed separation zone sandwiched between the airbag structure and the accommodation chamber, and an exhaust structure communicating the airbag structure with the accommodation chamber is provided in the sealed separation zone. The method further includes folding the airbag structure to the side of the sealing bag, placing the sealing bag with the folded airbag structure inside a second case, installing a second sealing cover plate to cover the opening of the second case, connecting the first conductive foil strip to a terminal on the second sealing cover plate, sealing the second sealing cover plate, and sealing the sealing bag inside the second case.

Brief Description of the Drawings

[0027] To more clearly illustrate the technical means in the embodiments of the present disclosure or related technologies, the drawings that need to be used in the description of the embodiments will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0029] Hereinafter, with reference to the drawings of the embodiments of the present disclosure, the technical means in the embodiments of the present disclosure will be described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of them. Based on the embodiments of the present disclosure, all other embodiments that can be achieved by those skilled in the art without creative work belong to the protection scope of the present disclosure.

[0030] In order to solve the problem that the performance of the aluminum electrolytic capacitor cannot be guaranteed in the capacitance extraction structure of the conventional rectangular aluminum electrolytic capacitor, the embodiment of the present disclosure provides a core package. For a plurality of first electrode foils of the core package, the first electrode foil and the first conductive foil strip are connected by a first conductive foil piece to realize the capacitance extraction of the first electrode foil. Since the connection area between the first conductive foil piece and the first electrode foil is large and easy to realize, the performance of the aluminum electrolytic capacitor can be effectively guaranteed. In addition, by installing an oxide film on the first conductive foil piece, the problem that a large amount of heat is generated due to current concentration at the connection position and the performance of the aluminum electrolytic capacitor cannot be guaranteed can be avoided.

[0031] As shown in FIGS. 1 to 3, in one embodiment of the embodiments of the present disclosure, the core package 10 includes a plurality of first electrode foils 100 and a plurality of second electrode foils 200 arranged in a stacked manner. One second electrode foil 200 is interposed between two adjacent first electrode foils 100, one first electrode foil 100 is interposed between two adjacent second electrode foils 200, and an electrolytic paper 300 is interposed between an adjacent first electrode foil 100 and second electrode foil 200. The first electrode foil 100 is either an anode foil or a cathode foil, and the second electrode foil 200 is the other of the anode foil and the cathode foil.

[0032] Among the plurality of first electrode foils 100, one first conductive foil piece 101 is provided at the edge of each first electrode foil 100. The first portion of the first conductive foil piece 101 is electrically connected to the corresponding first electrode foil 100, and the second portion of the first conductive foil piece 101 extends and protrudes with respect to the first electrode foil 100. The plurality of first conductive foil pieces are all connected to one first conductive foil strip 102 through the second portions. Here, an oxide film is formed on the surface of the first conductive foil piece 101.

[0033] In one aspect of the embodiments of the present disclosure, the plurality of first electrode foils 100 realize capacitance extraction by the first conductive foil pieces 101, and an oxide film (aluminum trioxide) is formed on the first conductive foil pieces 101. When performing an aging test, the oxide film broken by the connection at the electrical connection location between the first conductive foil piece 101 and the first electrode foil 100 can be repaired. Since an oxide film is formed on the first conductive foil pieces 101, during the use of the capacitor, the current does not concentrate and a large amount of heat is not generated due to the repair of the oxide film on the first conductive foil pieces by the electrolytic solution.

[0034] In the embodiments of the present disclosure, the first conductive foil piece 101 is made of a high-purity aluminum material and is thin, for example, with a thickness of 5 to 50 μm. The first conductive foil piece 101 having this structural characteristic can easily realize the connection with the first electrode foil 100, and can be connected, for example, by laser welding. The welding area of the laser welding between the first conductive foil piece 101 and the first electrode foil 100 is large, the connection is more stable, and the lateral tensile resistance is stronger.

[0035] On the one hand, in the conventional capacitor, the realization method of capacitance extraction by directly riveting the electrode foil and the conductive foil strip is such that the electrical connection between the two depends only on the connection location, the equivalent series resistance ESR of the capacitor is large, and the ripple current resistance performance of the capacitor is not high. In the embodiments of the present disclosure, between the first conductive foil strip 102 and the first conductive foil piece 101, and between the first conductive foil piece 101 and the first electrode foil 100, they can be connected by a welding form such as laser welding. Since the area of the electrical connection is large and the resistance of the electrical connection location can be effectively reduced, the problem that the equivalent series resistance ESR of the capacitor is large and the ripple current resistance performance of the capacitor is not high can be avoided.

[0036] Therefore, the first conductive foil strip 102 can be connected to the first electrode foil 100 through the first conductive foil piece 101. Compared with the realization method of capacitance extraction by directly riveting the conductive foil and the conductive foil strip in the conventional capacitor, when the conductive foil and the conductive foil strip are directly connected, due to the fact that the electrical connection between the two depends only on the connection location, the problem that the equivalent series resistance ESR of the capacitor is large and the ripple current resistance performance of the capacitor is not high can be avoided.

[0037] Note that the first part and the second part of the first conductive foil piece 101 are only used for distinguishing and explaining different parts of the first conductive foil piece 101. The two are substantially integrally formed to constitute the first conductive foil piece 101, and there is no boundary of distinction on the first conductive foil piece.

[0038] In the embodiments of the present disclosure, optionally, the first conductive foil piece 101 is made of a high-purity aluminum material, and an oxide film is formed on the surface through a forming process treatment. Moreover, it is preferable that the forming process treatment method on the surface of the first conductive foil piece 101 is the same as the forming process treatment method on the surface of the first electrode foil 100.

[0039] In this embodiment, the first conductive foil piece 101 is an aluminum foil piece, and an oxide film is formed on the surface using a chemical conversion process. That is, oxide films are formed on both the first electrode foil and the first conductive foil piece. When the first electrode foil and the first conductive foil piece are electrically connected, the oxide film at the connection location between the first electrode foil and the first conductive foil piece is broken and they are connected to each other. After undergoing an aging test during the manufacturing process of the capacitor, the broken oxide film on the surfaces of the first electrode foil and the first conductive foil piece is repaired. Due to the installation of the oxide film on the first conductive foil piece, after the production of the capacitor is completed, no current concentration and heat generation occur on the first conductive foil piece due to the repair or formation of the oxide film on the surface of the first conductive foil piece by the electrolytic solution.

[0040] Also, different from the formation of an oxide film on the conductive foil piece in the prior art, the conventional conductive foil piece cannot guarantee the realization of a welded connection with the electrode foil. However, in the embodiments of the present disclosure, the first conductive foil piece on which the oxide film is formed is solid high-purity aluminum and is thin, so an electrical connection by welding between the first conductive foil piece and the first electrode foil can be guaranteed.

[0041] Since the first conductive foil piece 101 is an aluminum foil piece and the chemical conversion process treatment method on the surface is the same as that on the surface of the first electrode foil 100, that is, the same as the chemical process treatment method on the surface in the treatment process of the first electrode foil 100, by adopting the same surface chemical process treatment method, the surface characteristics of the first conductive foil piece 101 are the same as those of the connected first electrode foil 100. In this way, when drawing capacitance by the first conductive foil piece 101 during the use of the aluminum electrolytic capacitor, the problem of current concentration and heat generation at the connection location is avoided.

[0042] In an embodiment of the present disclosure, the first electrode foil 100 is either an anode foil or a cathode foil, and the second electrode foil 200 is the other one of the anode foil and the cathode foil. That is, in one embodiment, either the anode foil or the cathode foil in the core package 10 can adopt the capacitance extraction structure of the above embodiment. Specifically, a first conductive foil piece having the same characteristics as the oxide film characteristics indicated by the connected first electrode foil is formed on the surface, so that the capacitance extraction of the first electrode foil 100 can be realized.

[0043] In one embodiment, optionally, as shown in FIG. 2, among a plurality of second electrode foils 200, one second conductive foil piece 201 is provided at the edge of each second electrode foil 200. The first portion of the second conductive foil piece 201 is electrically connected to the corresponding second electrode foil 200, and the second portion of the second conductive foil piece 201 extends and protrudes with respect to the second electrode foil 200. The plurality of second conductive foil pieces 201 are all connected to one second conductive foil strip 202 through the second portion. Here, an oxide film is formed on the surface of the second conductive foil piece 201.

[0044] Optionally, the characteristics of the oxide film on the surface of the second conductive foil piece are the same as those of the oxide film on the surface of the connected second electrode foil.

[0045] According to this embodiment, the capacitance extraction of the anode foil and the cathode foil in the core package 10 adopts a form in which conductive foil pieces are provided respectively.

[0046] For example, the first electrode foil 100 is an anode foil, the second electrode foil 200 is a cathode foil, one first conductive foil piece 101 is provided at the edge of each of the plurality of anode foils, the first conductive foil piece 101 is electrically connected to the corresponding first electrode foil 100, the plurality of first conductive foil pieces 101 are all connected to one first conductive foil strip 102 through the second portion, one second conductive foil piece 201 is provided at the edge of each of the plurality of cathode foils, the second conductive foil piece 201 is electrically connected to the corresponding second electrode foil 200, and the plurality of second conductive foil pieces 201 are all connected to one second conductive foil strip 202 through the second portion.

[0047] According to this implementation structure, in order to realize the capacitance extraction of the anode foil and the cathode foil of the core package 10, as shown in FIG. 1, a plurality of first conductive foil pieces 101 are connected to each other and connected to the first conductive foil strip 102 at the connection position 104 so as to be connected to the first conductive foil strip 102, and a plurality of second conductive foil pieces 201 are connected to each other and connected to the second conductive foil strip 202.

[0048] In another embodiment of the core package described in the embodiments of the present disclosure, as shown in FIG. 1 while referring to FIG. 4, the first electrode foil 100 is an anode foil, and the second electrode foil 200 is a cathode foil. Each cathode foil includes an integrally formed body portion 210 and a tab portion 220. The tab portion 220 protrudes with respect to the edge of the body portion 210. A plurality of cathode foils are connected to a single third conductive foil strip (not shown) via the tab portion 220.

[0049] In this embodiment, considering the differences in the production material costs and processes of the cathode foil and the production material costs and processes of the anode foil, it is not necessary for the cathode foil to adopt the same capacitance extraction structure as the anode foil. As shown in FIG. 4, by providing the tab portion 220, the capacitance extraction of the cathode foil can be realized.

[0050] Optionally, the cathode foil forms the tab portion 220 by cutting a part 230 from a rectangular base material to realize the capacitor function, and the body portion 210 of the cathode foil is constituted by the rectangular portion excluding the tab portion 220.

[0051] In one embodiment of the embodiments of the present disclosure, optionally, the thickness of the first conductive foil piece 101 is 5 to 50 μm, optionally 10 to 30 μm, and the width of the first conductive foil piece 101 is 5 to 50 mm, optionally 10 to 20 mm. Here, this width is the width in the edge direction along which the first conductive foil piece 101 is provided on the first electrode foil 100.

[0052] In another embodiment, when the capacitance of the second electrode foil 200 is drawn out by the second conductive foil piece 201, similarly, the thickness of the second conductive foil piece 201 is 5 to 50 μm, optionally 10 to 30 μm, and the width of the second conductive foil piece 201 is 5 to 50 mm, optionally 10 to 20 mm.

[0053] In the embodiments of the present disclosure, the thickness of the first conductive foil piece 101 or the second conductive foil piece 201 electrically connected to the anode foil is only 5 to 50 μm, preferably 5 to 20 μm. Since it is very small compared to the thickness of the anode foil, when a plurality of first electrode foils 100 and second electrode foils 200 are laminated in the core package 10, due to the installation of the first conductive foil piece 101 and the second conductive foil piece 201, the thickness of the connection portion between the anode foil and the first conductive foil piece 101 or the second conductive foil piece 201 does not increase significantly, and since the contact surface between the anode foil and the electrolytic paper is not flat, problems affecting the overall performance of the core package 10 such as stability and capacitance extraction are avoided.

[0054] In one embodiment of the embodiments of the present disclosure, optionally, between the first portion of the first conductive foil piece 101 and the first electrode foil 100, it is connected by one of rivet joining, welding, and conductive adhesive. Similarly, between the first portion of the second conductive foil piece 201 and the second electrode foil 200, it is connected by one of rivet joining, welding, and conductive adhesive.

[0055] Optionally, the rivet joining is any of cold rivet joining, hot rivet joining, and through-hole rivet joining, and the welding is laser welding. In order to ensure the flatness of the connection between the first conductive foil piece 101 and the second conductive foil piece 201, the first conductive foil piece 101 and the first electrode foil 100 are connected by laser welding, and the second conductive foil piece 201 and the second electrode foil 200 are connected by laser welding.

[0056] In one embodiment, optionally, the electrical connection process between the plurality of first conductive foil pieces 101 and between the plurality of first conductive foil pieces 101 and the first conductive foil strip 102 employs ultrasonic welding.

[0057] In one embodiment of the embodiments of the present disclosure, as shown in FIG. 5, each first electrode foil 100 includes an integrally formed body portion 110 and a tab portion 120. The tab portion 120 protrudes with respect to the edge of the body portion 110, and the first portion of the first conductive foil piece 101 is connected to the first electrode foil 100 through the tab portion 120. Here, the tab portions 120 of the plurality of first electrode foils 100 are sequentially arranged alternately along the first direction.

[0058] Optionally, the first direction is the extending direction of one edge of the first electrode foil 100.

[0059] In one embodiment, optionally, the width by which the tab portion 120 protrudes with respect to the body portion 110 is 3 mm to 5 mm.

[0060] Optionally, the plurality of first conductive foil pieces 101 are arranged in sequence along the first direction, and the second portions of two adjacent first conductive foil pieces 101 are adhesively connected.

[0061] According to this embodiment, the plurality of first conductive foil pieces 101 can be connected to the first electrode foil 100 through the tab portions 120 of the first electrode foil 100. Since the tab portions 120 of the plurality of first electrode foils 100 are sequentially arranged alternately along the first direction, the plurality of first conductive foil pieces 101 can be sequentially arranged along the first direction, and there is no problem that the connection between the plurality of first conductive foil pieces 101 and the first electrode foil 100 is stacked at one location due to the stacked arrangement of the first electrode foil 100, resulting in an increase in the thickness of the connection position between the first conductive foil piece 101 and the first electrode foil 100.

[0062] In the embodiments of the present disclosure, optionally, the first conductive foil strip 102 and the second conductive foil strip 202 each employ a tab. The tab has the same structure as the tab applied to a lithium-ion battery, and includes, for example, a conductive piece and a tab adhesive provided on the conductive piece.

[0063] In an embodiment of the present disclosure, optionally, one first conductive foil piece 101 is electrically connected to each anode foil, and the first conductive foil pieces 101 of a plurality of anode foils are stacked and arranged to be electrically connected. The plurality of first conductive foil pieces 101 are electrically connected to one first conductive foil strip 102. Similarly, when the cathode foil also extracts capacitance by means of the conductive foil piece, one second conductive foil piece 201 is electrically connected to each cathode foil, the second conductive foil pieces 201 of the plurality of cathode foils are stacked and arranged to be electrically connected, and the plurality of second conductive foil pieces 201 are electrically connected to one second conductive foil strip 202.

[0064] In one embodiment, optionally, as shown in FIG. 3, the electrolytic paper 300 on the core package 10 is integrally connected and formed in a "Z" - shaped structure in which the multilayer structures are parallel to each other and sequentially connected. The first electrode foil 100 and the second electrode foil 200 are respectively provided between two adjacent layer structures of the electrolytic paper 300. One second electrode foil 200 is interposed between two adjacent first electrode foils 100, and one first electrode foil 100 is interposed between two adjacent second electrode foils 200.

[0065] Optionally, in order to ensure effective separation of the first electrode foil 100 and the second electrode foil 200 by the electrolytic paper 300, the opposite ends of the electrolytic paper 300 extend and protrude with respect to the first electrode foil 100 and the second electrode foil 200, that is, the area of the portion of the electrolytic paper 300 facing the first electrode foil 100 and the second electrode foil 200 is larger than the areas of the first electrode foil 100 and the second electrode foil 200.

[0066] Optionally, among the first electrode foil 100 and the second electrode foil 200, the size of the cathode foil is slightly larger than or equal to the size of the anode foil.

[0067] In an embodiment of the present disclosure, optionally, the number of anode foils of the core package 10 is 1 to 100, preferably 10 to 60.

[0068] In an embodiment of the present disclosure, optionally, when the first electrode foil 100 and the first conductive foil strip 102 are connected by, for example, laser welding, in one embodiment, as shown in FIG. 2, the weld bead is arranged in the lateral direction, that is, the direction perpendicular to the direction from the first electrode foil 100 to the first conductive foil strip 102. In another embodiment, the weld bead is arranged in the longitudinal direction, that is, the direction parallel to the direction from the first electrode foil 100 to the first conductive foil strip 102, as shown in FIG. 6. Therefore, a specific connection method is not required, as long as the electrical connection between the first electrode foil 100 and the first conductive foil strip 102 can be ensured.

[0069] According to the core package described in the embodiment of the present disclosure, the capacitance extraction of a plurality of first electrode foils 100 is realized by the first conductive foil piece 101. Since the oxide film characteristics on the surface of the first electrode foil 100 are the same as the oxide film characteristics on the surface of the first conductive foil piece 101, when the aluminum electrolytic capacitor is used, there is no oxide film on the first conductive foil piece 101, and the oxide film is constantly repaired or formed on the first conductive foil piece by the electrolytic solution due to the difference in characteristics, and the current does not concentrate and generate heat.

[0070] In addition, since the thicknesses of the first conductive foil piece 101 and the second conductive foil piece 201 are much smaller than the thicknesses of the first electrode foil 100 and the second electrode foil 200, when multiple layers of the first electrode foil 100 and the second electrode foil 200 are laminated in the core package 10, the thickness of the corresponding location does not increase due to the installation of the first conductive foil piece 101 and the second conductive foil piece 201, and problems that affect the overall performance of the core package 10, such as stability and capacitance extraction, due to the non-flat contact surface between the first conductive foil piece 101 and the second conductive foil piece 201 and the electrolytic paper are avoided.

[0071] The embodiment of the present disclosure also provides an aluminum electrolytic capacitor including the core package with the above-described implementation structure.

[0072] In one embodiment, the aluminum electrolytic capacitor further includes a first case made of an aluminum material with one end open, and the core package is provided inside the first case. A first sealing cover plate is provided at the opening, terminals are provided on the first sealing cover plate, and the first conductive foil strip is connected to the terminals on the first sealing cover plate.

[0073] Optionally, the dimensions and shape of the first case match the dimensions and shape of the core package. In one embodiment thereof, when the core package is formed into a rectangular body, the first case is formed into a rectangular body that matches the size of the core package.

[0074] In this embodiment, the core package is sealed by a first case made of an aluminum material and a first sealing cover plate. The core package including the first electrode foil, the second electrode foil, and the electrolytic paper is directly placed inside the first case and sealed by the first sealing cover plate. Optionally, the space between the first case and the first sealing cover plate may be sealed with a sealing adhesive or by laser welding.

[0075] In an embodiment of the present disclosure, the first conductive foil strip is a tab and includes a conductive piece and a tab adhesive provided on the conductive piece. The tab adhesive is formed as a connection tape. The first conductive foil strip is connected to the terminals on the first sealing cover plate.

[0076] Optionally, the first electrode foil is an anode foil, and the core package further includes a second conductive foil strip or a third conductive foil strip that connects to the cathode foil. Similarly, the second conductive foil strip or the third conductive foil strip is connected to another terminal on the first sealing cover plate to realize the capacitance extraction of the cathode foil.

[0077] Here, the terminals on the first sealing cover plate are connected to the first conductive foil strip and the second conductive foil strip (or the third conductive foil strip) on the inside and to the wiring board on the outside.

[0078] In an embodiment of the present disclosure, the core package provided within the first case is impregnated with an electrolytic solution containing a solvent, a solute, and an additive.

[0079] The solvent includes a main solvent and an auxiliary solvent. The main solvent is ethylene glycol, and the auxiliary solvent includes one or more of deionized water, glycerin, glycerol, sorbitol, propylene glycol, and 1,4-butanediol. The auxiliary solvent may or may not be present.

[0080] The solute includes one or more of succinic acid, glutaric acid, adipic acid, ammonium adipate, ammonium suberate, ammonium azelate, ammonium sebacate, ammonium 1,7-sebacate, ammonium isosebacate, ammonium alkyl sebacate, ammonium dodecanoate, 2-hexyl adipic acid, boric acid, polyvinyl alcohol, polyethylene glycol, butyl phosphate, monobutyl phosphate, ammonium pentaborate, phthalic acid, terephthalic acid, and citric acid.

[0081] The additive includes one or more of p-nitrophenol, o-nitrophenol, m-dinitrobenzene, p-nitroanisole, or p-nitrobenzylmethanol, and ammonium hypophosphite.

[0082] In another embodiment of the core package sealing in the embodiments of the present disclosure, as shown in FIGS. 7 to 9 with reference to FIG. 1, the aluminum electrolytic capacitor further includes a sealing bag 400 made of an aluminum plastic film. The sealing bag 400 is formed with a receiving chamber 410 whose edge is sealed to seal the core package 10 inside the sealing bag 400. The first conductive foil strip 102 extends outside the sealing bag 400 through the first sealing edge 401 of the sealing bag 400.

[0083] According to this embodiment, the core package 10 is sealed by a sealing bag 400 made of an aluminum plastic film. Optionally, in the core package 10, the first conductive foil strip connected to the anode foil, the second conductive foil strip or the third conductive foil strip connected to the cathode foil is hermetically connected to the first sealing edge 401 by a connection tape 103 respectively.

[0084] Here, after the core package 10 is installed in the accommodation chamber 410 of the sealing bag 400, the first conductive foil strip and the second conductive foil strip (or the third conductive foil strip) are heat-sealed at the edge extending from the sealing bag 400 to form the first sealing edge 401.

[0085] Similar to the sealing method of the above embodiment of the core package 10, the core package in the accommodation chamber 410 is impregnated with an electrolytic solution, and the electrolytic solution contains a solvent, a solute and an additive.

[0086] In one embodiment, optionally, the sealing bag 400 further includes an airbag structure 420 with a separation zone 402 sandwiched between the accommodation chamber 410, and an exhaust structure 421 communicating the airbag structure 420 and the accommodation chamber 410 is opened in the separation zone 402.

[0087] Optionally, this exhaust structure 421 is formed as a through hole or a one-way pressure relief valve. In one embodiment, the exhaust structure 421 is disposed at the central position of the separation zone 402.

[0088] In the embodiments of the present disclosure, the separation zone 402 is formed by heat sealing.

[0089] Here, the separation zone 402 faces the first sealing edge 401 of the sealing bag 400 or is located on the adjacent side of the first sealing edge 401.

[0090] As shown in FIGS. 7 to 9, the width of the second sealing edge 403 of the sealing bag 400 is larger than the width of the first sealing edge 401. Here, the second sealing edge 403 is located on both sides of the first sealing edge 401.

[0091] Optionally, as shown in FIG. 8, the second sealing edge 403 includes at least two sealing separation zones.

[0092] In this embodiment, the sealing separation zone is formed by heat sealing. Here, by making the width of the second sealing edge 403 on both sides of the first sealing edge 401 larger than the width of the first sealing edge 401, the sealing effect of the sealing bag 400 when the first sealing edge 401 is sealed by heat sealing is effectively guaranteed.

[0093] As shown in FIG. 9, the sealing bag 400 is provided with a spaced accommodation chamber 410 and an airbag structure 420, and by using the sealing separation zone 402 located between the accommodation chamber 410 and the airbag structure 420, the airbag structure 420 can be folded with respect to the accommodation chamber 410.

[0094] In an embodiment of the present disclosure, optionally, as shown in FIG. 10, the aluminum electrolytic capacitor further includes a second case 500 with one end open, the sealing bag 400 containing the core package is provided inside the second case 500, a second sealing cover plate 600 is provided at the opening, terminals are provided on the second sealing cover plate 600, and the first conductive foil strip is connected to the terminals on the second sealing cover plate 600.

[0095] In this embodiment, the second case 500 may be made of any material such as aluminum material, polyurethane material, etc., and is not specifically limited.

[0096] In an embodiment of the present disclosure, inside the second case 500, the airbag structure 420 is provided on one side of the accommodation chamber 410. Here, the direction from the accommodation chamber 410 to the airbag structure 420 is the stacking arrangement direction of the plurality of first electrode foils and the plurality of second electrode foils.

[0097] According to this embodiment, as shown in FIG. 10, after the core package 10 is sealed in the accommodation chamber 410, the airbag structure 420 is folded to one side with respect to the accommodation chamber 410, and then the entire sealing bag 400 is placed in the second case 500. Optionally, a small gap is provided between the sealing bag 400 and the second case 500 inside the second case 500.

[0098] In the aluminum electrolytic capacitor according to this embodiment structure, when gas is generated in the accommodation chamber 410 during use and gas expansion occurs, the generated gas first enters the airbag structure 420 through the exhaust structure 421 that communicates the airbag structure 420 and the accommodation chamber 410. Since the airbag structure 420 is located on one side of the accommodation chamber 410, when the accommodation chamber 410 expands, it presses the core package in the accommodation chamber 410. When the core package is pressed, it becomes more compact, achieving the effect of reducing the attenuation rate of the capacitance extraction rate of the core package.

[0099] Also, according to the aluminum electrolytic capacitor described in the embodiments of the present disclosure, since the gas generated in the core package is first accumulated in the airbag structure 420, it does not pop out from the pressure relief valve on the aluminum case like a conventional capacitor and sputter on the wiring board, thus not causing accident problems such as ignition.

[0100] On the other hand, in the embodiments of the present disclosure, since the first conductive foil strip (or the second conductive foil strip) is hermetically connected to the sealing bag by the connection tape, the connection strength at the connection tape is weaker than other locations. When the gas pressure generated in the sealing bag reaches a certain level, a break occurs at the sealing position between the connection tape and the sealing bag or at the connection position between the first conductive foil strip (or the second conductive foil strip) and the cathode foil. When it breaks, the power supply of the capacitor is cut off and gas generation stops, thus avoiding the problem of a large amount of gas popping out and sputtering on the wiring board.

[0101] For example, with a test condition of a voltage of 660V and a current of 1A, a plurality of aluminum electrolytic capacitors of the embodiments of the present disclosure are tested. After the power is turned on and 1 to 2 seconds have passed since reaching the test condition instantaneously, the second conductive foil strip on the cathode foil breaks at the aluminum plastic sealing position or at the rivet joint position of the cathode foil (the cathode foil is thin and prone to breakage).

[0102] Furthermore, since the sealing bag 400 is also provided in the second case 500, even if the electrolytic solution in the core package leaks, it only leaks into the second case 500 and generally does not flow out, and there is no problem of sputtering on the wiring board, and a flame retardant effect can be obtained.

[0103] In one embodiment, optionally, a pressing clip 700 is further provided in the second case 500. As shown in FIG. 11, the pressing clip 700 clamps the accommodation chamber 410, and the airbag structure 420 is located on one side of the pressing clip 700.

[0104] Optionally, the pressing clip 700 includes two opposing clamp plates, and the two clamp plates clamp the accommodation chamber 410 to clamp the core package in the accommodation chamber 410.

[0105] According to this embodiment, the accommodation chamber 410 is clamped by the pressing clip 700. When gas is generated in the core package in the accommodation chamber 410 during the operation of the capacitor, the gas in the accommodation chamber 410 reaches the airbag structure 420 quickly by the pressing clip 700, so that the gas does not stay in the accommodation chamber 410, and the reverse pressure of the accommodation chamber 410 caused by the gas in the airbag structure 420 is not affected.

[0106] Optionally, after the core package is sealed in the sealing bag 400, by performing vacuum pumping, the sealing bag 400 can be made to adhere closely to the core package.

[0107] Optionally, the sealing bag 400 is pre-formed in advance. When pre-forming the sealing bag 400 in advance, it includes pre-forming a sealed separation zone between the accommodation chamber and the airbag structure in advance.

[0108] When sealing the core package, first, a heat-sealing adhesive is attached to the first conductive foil strip connected to the anode foil and the second conductive foil strip connected to the cathode foil, and then the packaging, evacuation, and sealing process by heat-sealing of the core package are executed.

[0109] In one of its embodiments, optionally, the formation of the sealing bag is to place the core package on one aluminum-plastic film, then cover the core package with one aluminum-plastic film, and then seal the edges by heat-sealing to form an accommodation chamber and an airbag structure in the aluminum-plastic film.

[0110] When the capacitor is in use, due to the problem of ripple current, it may generate heat, and the electrolytic solution may evaporate or gas may be generated. Therefore, the evaporated electrolytic solution also enters the airbag structure along the exhaust structure. So, it is necessary for the core package to be impregnated with sufficient electrolytic solution. In fact, the square laminated core package is not wound as tightly as the wound cylindrical core package, so the electrolytic solution easily penetrates the entire core package. That is, under the same impregnation conditions, the square laminated core package can be impregnated with more electrolytic solution, and the performance of the capacitor is excellent.

[0111] Also, since the core package is sealed by a sealing bag made of aluminum-plastic film, the requirement for the sealing effect on the core package in the second case is not as high as that of the conventional capacitor. The terminal (lead-out terminal) may be installed in the same installation method as that of the conventional capacitor terminal after sealing the sealing bag in the second case with the second cover plate. However, the sealing requirement between the second cover plate and the second case is not very high, and it only needs to be ensured that when gas is generated in the core package and reaches a certain degree to rupture the sealing bag, the electrolytic solution does not flow out from the second case.

[0112] On the one hand, after putting the core package into the sealing bag 400 and sealing it, when performing the aging test, if gas is generated and there is an inflation phenomenon during the aging test, according to the aluminum electrolytic capacitor described in the embodiments of the present disclosure, the gas enters the airbag structure 420 through the exhaust structure 421 and inflates the airbag structure 420. In this case, a notch is made in the airbag structure, the gas in the airbag structure is exhausted by vacuuming, and then the notch is heat-sealed again.

[0113] In another embodiment of the aluminum electrolytic capacitor according to the embodiments of the present disclosure, the aluminum electrolytic capacitor further includes an integrally formed second case, the sealing bag containing the core package is provided inside the second case, the first conductive foil strip protrudes outside the second case, and between the first conductive foil strip and the second case, it is sealed and insulated.

[0114] In this embodiment, the second case is made of an aluminum case, the sealing bag containing the core package is provided inside the second case made of an integrally formed aluminum case, and the first conductive foil strip and the second conductive foil strip (or the third conductive foil strip) protrude outside the second case to realize the extraction of capacitance. Between the first conductive foil strip and the second conductive foil strip (or the third conductive foil strip) and the second case, it is sealed and insulated by a rubber stopper.

[0115] Optionally, in this embodiment, similar to the above embodiment where the sealing bag containing the core package is sealed by a second case with an opening at one end and a second sealing cover plate, the sealing bag also includes an airbag structure, a pressing clamp for clamping the accommodation chamber, etc. For specific embodiments, reference can be made to the above description regarding the airbag structure and the pressing clamp, and details are not described here.

[0116] Another aspect of the embodiments of the present disclosure further provides a sealing method applicable to the above aluminum electrolytic capacitor. The method includes placing a core package in a receiving chamber of a sealing bag made of an aluminum plastic film such that a first conductive foil strip of the sealing bag penetrates through an opening of the sealing bag, heat-sealing the sealing bag at the opening to form a first sealing edge, and heat-sealing a connection colloid of the first conductive foil strip to the sealing bag.

[0117] Optionally, the sealing bag further includes an airbag structure sandwiching a sealed separation zone from the receiving chamber, and an exhaust structure communicating the airbag structure with the receiving chamber is provided in the sealed separation zone. The method further includes folding the airbag structure to the side of the sealing bag, placing the sealing bag with the folded airbag structure inside a second case, installing a second cover plate to cover an opening of the second case, connecting the first conductive foil strip to a terminal on the second sealing cover plate, sealing the second sealing cover plate, and sealing the sealing bag inside the second case.

[0118] Specifically, the sealing method and process for sealing an aluminum electrolytic capacitor can refer to the above description and will not be described in detail here.

[0119] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and its equivalent technologies, the present disclosure is also intended to include these changes and modifications.

Claims

1. A core package, comprising: a plurality of first electrode foils and a plurality of second electrode foils arranged in a stacked manner, one of the second electrode foils is interposed between two adjacent first electrode foils, one of the first electrode foils is interposed between two adjacent second electrode foils, an electrolytic paper is interposed between the adjacent first electrode foil and the second electrode foil, the first electrode foil is either an anode foil or a cathode foil, and the second electrode foil is the other of the anode foil and the cathode foil, among the plurality of first electrode foils, one first conductive foil piece is provided at the edge of each first electrode foil, a first portion of the first conductive foil piece is electrically connected to the corresponding first electrode foil, a second portion of the first conductive foil piece extends and protrudes with respect to the first electrode foil, and the plurality of first conductive foil pieces are all connected to one first conductive foil strip through the second portion, wherein an oxide film is formed on the surface of the first conductive foil piece. The core package.

2. Among the plurality of second electrode foils, one second conductive foil piece is provided at the edge of each second electrode foil, a first portion of the second conductive foil piece is electrically connected to the corresponding second electrode foil, a second portion of the second conductive foil piece extends and protrudes with respect to the second electrode foil, and the plurality of second conductive foil pieces are all connected to one second conductive foil strip through the second portion, wherein an oxide film is formed on the surface of the second conductive foil piece. The core package according to claim 1.

3. The first conductive foil piece is made of a pure aluminum material, and the characteristics of the oxide film on the surface of the first conductive foil piece are the same as those of the oxide film on the surface of the first electrode foil. The core package according to claim 1.

4. The oxide film is formed on the surface of the first conductive foil piece through a chemical conversion process treatment, and the chemical conversion process treatment method for forming the oxide film on the surface of the first conductive foil piece is the same as the chemical conversion process treatment method for forming the oxide film on the surface of the first electrode foil. The core package according to claim 1.

5. The first electrode foil is an anode foil, and the second electrode foil is a cathode foil, each cathode foil includes an integrally formed body portion and a tab portion, the tab portion protrudes with respect to the edge of the body portion, and the plurality of cathode foils are connected to one third conductive foil strip through the tab portion. The core package according to claim 1.

6. Each of the first electrode foils includes an integrally formed body portion and a tab portion. The tab portion protrudes with respect to an edge of the body portion. The first portion of the first conductive foil piece is connected to the first electrode foil through the tab portion. Here, the tab portions of the plurality of first electrode foils are sequentially arranged alternately along a first direction. The core package according to claim 1.

7. The plurality of first conductive foil pieces are arranged in order along the first direction, and the second portions of two adjacent first conductive foil pieces are adhesively connected. The core package according to claim 6.

8. The thickness of the first conductive foil piece is 5 to 50 μm. The core package according to claim 1.

9. Between the first portion of the first conductive foil piece and the first electrode foil, it is connected by one of rivet bonding, welding, and a conductive adhesive. The core package according to claim 1.

10. An aluminum electrolytic capacitor including the core package according to any one of claims 1 to 9.

11. Further including a first case with one end open and made of an aluminum material, The core package is provided inside the first case, A first sealing cover plate is provided at the opening, a terminal is provided on the first sealing cover plate, and the first conductive foil strip is connected to the terminal on the first sealing cover plate. The aluminum electrolytic capacitor according to claim 10.

12. The dimensions and shape of the first case are adapted to the dimensions and shape of the core package. The aluminum electrolytic capacitor according to claim 11.

13. Further including a sealing bag made of an aluminum plastic film, The sealing bag has its edges sealed to form a housing chamber for sealing the core package inside the sealing bag, and the first conductive foil strip extends outside the sealing bag through the first sealing edge of the sealing bag. The aluminum electrolytic capacitor according to claim 10.

14. Further including a second case with one end open, The sealing bag containing the core package is provided inside the second case, A second sealing cover plate is provided at the opening, a terminal is provided on the second sealing cover plate, and the first conductive foil strip is connected to the terminal on the second sealing cover plate. The aluminum electrolytic capacitor according to claim 13.

15. Further including an integrally formed second case, The sealing bag is provided inside the second case, the first conductive foil strip protrudes outside the second case, and the space between the first conductive foil strip and the second case is sealed and insulated. The aluminum electrolytic capacitor according to claim 13.

16. The sealing bag further includes an airbag structure with a separation zone sandwiched between it and the accommodation chamber, and an exhaust structure communicating the airbag structure and the accommodation chamber is provided in the separation zone. Inside the second case, the airbag structure is provided on one side of the accommodation chamber. Here, the direction from the accommodation chamber to the airbag structure is the stacking direction of the plurality of first electrode foils and the plurality of second electrode foils. The aluminum electrolytic capacitor according to claim 14 or 15.

17. Inside the second case, a pressing clamp for sandwiching the accommodation chamber is further provided. The airbag structure is located on one side of the pressing clamp. The aluminum electrolytic capacitor according to claim 16.

18. The separation zone faces the first sealing edge of the sealing bag or is located on the side adjacent to the first sealing edge. The aluminum electrolytic capacitor according to claim 16.

19. The width of the second sealing edge of the sealing bag is larger than the width of the first sealing edge. The second sealing edge is located on both sides of the first sealing edge. The aluminum electrolytic capacitor according to claim 13.

20. The second sealing edge includes at least two sealed separation zones. The aluminum electrolytic capacitor according to claim 19.

21. A sealing method applicable to the aluminum electrolytic capacitor according to claim 10, comprising: placing a core package in an accommodation chamber of a sealing bag made of an aluminum plastic film such that a first conductive foil strip of the core package penetrates through an opening of the sealing bag; heat-sealing the sealing bag at the opening to form a first sealing edge, and heat-sealing a connection colloid on the first conductive foil strip to the sealing bag; A sealing method including the above steps.

22. The sealing bag further includes an airbag structure with a sealed separation zone sandwiched between it and the accommodation chamber, and an exhaust structure communicating the airbag structure and the accommodation chamber is provided in the sealed separation zone. The method includes: folding the airbag structure to the side of the sealing bag; placing the sealing bag with the folded airbag structure inside the second case. Install a second cover plate so as to cover the opening of the second case, and connect the first conductive foil strip to a terminal on the second sealing cover plate. Seal the second sealing cover plate and seal the sealed bag inside the second case. The sealing method according to claim 21, further comprising the above steps.

Images