Laminated solid aluminum electrolytic capacitor and preparation method thereof

Abstract

The invention provides a laminated solid aluminum electrolytic capacitor and a preparation method thereof, the laminated solid aluminum electrolytic capacitor comprises laminated single capacitors, each single capacitor comprises an anode region and a cathode region, the anode regions of the single capacitors are oppositely arranged, and the cathode regions of the single capacitors are oppositely arranged; the cathode region comprises a conductive base material containing an oxide film layer, and the oxide film layer is sequentially covered with an ionic liquid layer, a metal material layer, a non-metal conductive layer and a metal conductive layer; the ionic liquid layer comprises ionic liquid; the metal material layer comprises a metal organic framework compound. The laminated solid aluminum electrolytic capacitor is low in leakage current, high in circuit stability and energy efficiency, low in heat generation, capable of avoiding heating of the capacitor in a high-frequency circuit and influence on the circuit stability, high in qualified rate, long in service life, remarkable in economic and social benefits and high in application value.

Description

Technical Field

[0001] The present invention relates to the field of aluminum electrolytic capacitors, and in particular to a laminated solid aluminum electrolytic capacitor and a preparation method thereof. Background Art

[0002] The laminated solid aluminum electrolytic capacitor is a new type of chip electronic component product that uses a conductive polymer material with high conductivity as the solid electrolyte. It has many advantages such as smaller size, better performance, wide temperature range, long life, high reliability and high environmental protection. It can cater to the development trend of miniaturization, high frequency, high speed, high reliability and high environmental protection of electronic products.

[0003] In high-frequency circuits, existing multilayer solid aluminum electrolytic capacitors are prone to overheating due to excessive leakage current. Once the capacitor is overheated, it will have a negative impact on the stability of the circuit.

[0004] Therefore, the multilayer solid aluminum electrolytic capacitor still needs to be studied. Summary of the invention

[0005] The present invention aims to solve the technical problems existing in the prior art at least to a certain extent. To this end, the present invention proposes a laminated solid aluminum electrolytic capacitor and a preparation method thereof. The laminated solid aluminum electrolytic capacitor of the present invention has low leakage current, high circuit stability and energy efficiency, less heat generation, avoids capacitor heating under high-frequency circuits and the influence on circuit stability, has a high pass rate, and a long service life of the capacitor, has significant economic and social benefits, and has high application value.

[0006] In one aspect of the present invention, the present invention proposes a laminated solid aluminum electrolytic capacitor. According to an embodiment of the present invention, the laminated solid aluminum electrolytic capacitor includes a laminated single capacitor, the single capacitor includes an anode region and a cathode region, the anode region of each single capacitor is arranged relative to each other, and the cathode region of each single capacitor is arranged relative to each other; the cathode region includes a conductive substrate containing an oxide film layer, and the oxide film layer is sequentially covered with an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer; the ionic liquid layer includes an ionic liquid; and the metal material layer includes a metal organic framework compound.

[0007] In the laminated solid aluminum electrolytic capacitor according to the embodiment of the present invention, the neutral or weakly alkaline characteristics of the ionic liquid and the metal organic framework compound are utilized to prepare the cathode layer of the laminated solid aluminum electrolytic capacitor, so that the oxide film layer of the laminated solid aluminum electrolytic capacitor is not corroded and damaged, thereby ensuring that the laminated solid aluminum electrolytic capacitor has low leakage current, high circuit stability and energy efficiency, and less heat generation, avoiding heating of the capacitor in a high-frequency circuit and the influence on the circuit stability, with a high pass rate, a long service life of the capacitor, and high application value.

[0008] According to an embodiment of the present invention, the above-mentioned laminated solid aluminum electrolytic capacitor may also have the following additional technical features:

[0009] According to an embodiment of the present invention, the ionic liquid includes an imidazole ionic liquid.

[0010] According to an embodiment of the present invention, the imidazole ionic liquid has the structure shown below:

[0011]

[0012] Wherein, X1 is selected from methyl, ethyl, propyl, isopropyl, butyl or tert-butyl;

[0013] X2 is selected from methyl, ethyl, propyl, isopropyl, tert-butyl or cyclohexyl;

[0014] X3 - Selected from Cl - Br - ,I - 、CH3SO4 - 、CH3CH2SO4 - 、BF4 - 、(CH3)2PO4 - 、(CH3CH2)2PO4 - 、NO3 - or CH3COO - .

[0015] According to an embodiment of the present invention, the imidazole ionic liquid has a structure shown in any one of the following:

[0016]

[0017]

[0018] According to an embodiment of the present invention, the metal organic framework compound is selected from zeolite imidazolate metal compounds.

[0019] According to an embodiment of the present invention, the metal organic framework compound has the structure shown below:

[0020]

[0021] Wherein, X4 is selected from Zn or Co.

[0022] According to an embodiment of the present invention, the conductive substrate is selected from chemically formed foil; the oxide film layer includes an aluminum oxide film; the non-metallic conductive layer includes at least one of conductive graphite, graphene, carbon nanotubes, and conductive carbon black, preferably containing at least conductive graphite; the metal conductive layer includes at least one of copper, silver, silver-coated copper, gold, tin, aluminum, nickel, zinc, and platinum, preferably containing at least silver.

[0023] According to an embodiment of the present invention, the stacked solid aluminum electrolytic capacitor further includes: an anode pin, on which the anode region of the stacked single capacitor is relatively stacked and connected; a cathode pin, on which the cathode region of the stacked single capacitor is relatively stacked and connected; and a packaging material, which is used to package the stacked single capacitor; wherein the number of the stacked single capacitors is 6 to 16.

[0024] In another aspect of the present invention, the present invention proposes a method for preparing the aforementioned laminated solid aluminum electrolytic capacitor. According to an embodiment of the present invention, the method includes: (1) separating an anode region and a cathode region on a conductive substrate containing an oxide film layer, and sequentially forming an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer covering the oxide film layer on the cathode region to obtain a single capacitor; (2) stacking the single capacitors so that the anode region of each single capacitor is relatively arranged and the cathode region of each single capacitor is relatively arranged. As a result, the laminated solid aluminum electrolytic capacitor prepared by the method according to an embodiment of the present invention has low leakage current, high circuit stability and energy efficiency, less heat generation, avoids heating of the capacitor under high-frequency circuits and the influence on circuit stability, has a high pass rate, a long service life of the capacitor, and high application value. The preparation method is simple to operate, low cost, and suitable for industrial production.

[0025] According to an embodiment of the present invention, step (1) includes: subjecting the cathode region of the conductive substrate to a first immersion treatment and a first drying treatment in an aqueous solution containing the imidazole ionic liquid, and obtaining a conductive substrate whose cathode region is covered with an ionic liquid layer; the first immersion treatment and the first drying treatment are repeated 5 to 10 times respectively; subjecting the cathode region of the conductive substrate covered with the ionic liquid layer to a second immersion treatment and a second drying treatment in an aqueous solution containing the metal organic framework compound, and obtaining a conductive substrate whose cathode region is sequentially covered with an ionic liquid layer and a metal material layer; the second immersion treatment and the second drying treatment are repeated 5 to 15 times respectively; a non-metallic conductive layer and a metal conductive layer are sequentially formed on the cathode region of the conductive substrate sequentially covered with an ionic liquid layer and a metal material layer, and a single capacitor is obtained.

[0026] According to an embodiment of the present invention, the concentration of the imidazole ionic liquid in the aqueous solution containing the imidazole ionic liquid is 5wt%-15wt%; the concentration of the metal organic framework compound in the aqueous solution containing the metal organic framework compound is 10wt%-20wt%.

[0027] According to an embodiment of the present invention, in step (1), since imidazole ionic liquids react more easily and under milder conditions than metal organic framework compounds, the temperature of the first impregnation treatment is lower than the temperature of the second impregnation treatment, and the temperature of the first drying treatment is lower than the temperature of the second drying treatment each time the cycle is repeated.

[0028] According to an embodiment of the present invention, the temperature of the first immersion treatment is 10°C to 35°C, and the time is 0.5min to 15min; the temperature of the first drying treatment is 80°C to 125°C, and the time is 5min to 50min; the temperature of the second immersion treatment is 20°C to 40°C, and the time is 3min to 10min; the temperature of the second drying treatment is 90°C to 135°C, and the time is 10min to 50min.

[0029] According to an embodiment of the present invention, step (2) comprises: respectively stacking the anode regions of the single capacitors relatively and connecting the anode lead frames, and stacking the cathode regions of the single capacitors relatively and connecting the cathode lead frames, and then extruding and curing to obtain a battery cell; packaging the battery cell in a packaging material, removing the anode lead frame and the cathode lead frame from the packaged capacitor, bending the pins to form a connection structure, and then performing heat treatment, moisture absorption treatment and aging treatment to obtain the laminated solid aluminum electrolytic capacitor.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : A schematic structural diagram of a cathode region of a single capacitor provided according to some embodiments of the present invention;

[0032] Figure 2 : A schematic structural diagram of the cathode region of a single capacitor provided according to some other embodiments of the present invention.

[0033] 10 - cathode region of a conductive substrate containing an oxide film layer, 20 - ionic liquid layer, 30 - metal material layer, 40 - non-metallic conductive layer, 50 - metal conductive layer. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0035] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0036] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article.

[0037] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0038] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0039] The present invention provides a laminated solid aluminum electrolytic capacitor and a preparation method thereof, which will be described in detail below.

[0040] Multilayer solid aluminum electrolytic capacitors

[0041] In one aspect of the present invention, the present invention proposes a laminated solid aluminum electrolytic capacitor. According to an embodiment of the present invention, the laminated solid aluminum electrolytic capacitor includes a laminated single capacitor, the single capacitor includes an anode region and a cathode region, the anode region of each single capacitor is arranged relative to each other, and the cathode region of each single capacitor is arranged relative to each other; the cathode region includes a conductive substrate containing an oxide film layer, the oxide film layer is sequentially covered with an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer; the ionic liquid layer includes an ionic liquid; the metal material layer includes a metal organic framework compound.

[0042] In the laminated solid aluminum electrolytic capacitor according to the embodiment of the present invention, the cathode layer of the laminated solid aluminum electrolytic capacitor is prepared by utilizing the neutral or weak alkalinity characteristics of the ionic liquid and the metal organic framework compound, so that the oxide film layer of the laminated solid aluminum electrolytic capacitor is not corroded and damaged. In addition, compared with the metal organic framework compound, the melting point of the ionic liquid is low, and it is easy to form an ionic liquid layer, while the reaction temperature for forming the metal organic framework compound layer is high. In order to avoid damage to the oxide film layer, the ionic liquid layer is first covered on the oxide film layer, and then the metal organic framework compound layer is covered. Thus, it can be effectively ensured that the leakage current of the laminated solid aluminum electrolytic capacitor is low, the circuit stability and energy efficiency are high, the heat generation is small, the capacitor heating under the high-frequency circuit and the influence on the circuit stability are avoided, the qualified rate is high, the capacitor has a long service life, and the application value is high.

[0043] In some embodiments, for a conductive substrate containing an oxide film layer, an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer are sequentially covered on the oxide film layers on opposite sides thereof (see Figure 1 ), or an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer may be sequentially covered on the oxide film layer on one side (see Figure 2 ), can be flexibly selected according to actual needs, wherein it is preferred to cover each layer of material on the oxide film layers on the opposite sides, which is convenient for operation and preparation, and the product performance is also better.

[0044] According to an embodiment of the present invention, the ionic liquid includes an imidazole ionic liquid. Compared with other types of ionic liquids, the imidazole ionic liquid has a lower melting point, is conducive to penetrating into the pores, is easy to deposit, has a small molecular volume, and the compound is neutral or weakly alkaline, which avoids the corrosion of the oxide film by acidic substances, has a higher conductivity, and is cheap and easy to obtain.

[0045] According to an embodiment of the present invention, the imidazole ionic liquid has the structure shown below:

[0046]

[0047] wherein X1 is selected from methyl, ethyl, propyl, isopropyl, butyl or tert-butyl; X2 is selected from methyl, ethyl, propyl, isopropyl, tert-butyl or cyclohexyl; X3 - Selected from Cl - Br - ,I - 、CH3SO4 - 、CH3CH2SO4 - 、BF4 - 、(CH3)2PO4 - 、(CH3CH2)2PO4 - 、NO3 -or CH3COO - Thus, the leakage current of the multilayer solid aluminum electrolytic capacitor can be effectively reduced.

[0048] According to an embodiment of the present invention, the imidazole ionic liquid has a structure shown in any of the following:

[0049] The use of the above-mentioned imidazole ionic liquid can effectively reduce the leakage current of the laminated solid aluminum electrolytic capacitor.

[0050] In this article, the term "metal organic framework compound" refers to a type of crystalline porous material with a periodic network structure formed by the self-assembly of inorganic metal centers (metal ions or metal clusters) and bridging organic ligands. In some embodiments, the metal organic framework compound is selected from zeolite imidazolate metal compounds. Compared with other types of metal organic framework compounds, zeolite imidazolate metal compounds have a clear structure, are neutral or weakly alkaline, can effectively avoid the corrosion of acidic substances to the oxide film, have stable physical and chemical properties, are easy to deposit, and the research on this type of compound is the most extensive and in-depth, and is cheap and easy to obtain.

[0051] According to an embodiment of the present invention, the metal organic framework compound has the structure shown below:

[0052]

[0053] Wherein, X4 is selected from Zn or Co. The use of the metal organic framework compound can effectively reduce the leakage current of the laminated solid aluminum electrolytic capacitor.

[0054] According to an embodiment of the present invention, the conductive substrate is selected from chemically formed foil; the oxide film layer includes an aluminum oxide film; the non-metallic conductive layer includes at least one of conductive graphite, graphene, carbon nanotubes, and conductive carbon black, preferably containing at least conductive graphite; the metal conductive layer includes at least one of copper, silver, silver-coated copper, gold, tin, aluminum, nickel, zinc, and platinum, preferably containing at least silver.

[0055] According to an embodiment of the present invention, the stacked solid aluminum electrolytic capacitor further includes: an anode pin, the anode region of the stacked single capacitor is relatively stacked and connected to the anode pin; a cathode pin, the cathode region of the stacked single capacitor is relatively stacked and connected to the cathode pin; and a packaging material, the packaging material is used to encapsulate the stacked single capacitor. According to an embodiment of the present invention, the stacked single capacitor is 6 to 16. In some embodiments, the stacked single capacitor is 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or a range value formed by any two values ​​as endpoint values.

[0056] Method for preparing laminated solid aluminum electrolytic capacitor

[0057] In another aspect of the present invention, the present invention proposes a method for preparing the aforementioned laminated solid aluminum electrolytic capacitor. According to an embodiment of the present invention, the method includes: (1) separating an anode region and a cathode region on a conductive substrate containing an oxide film layer, and sequentially forming an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer covering the oxide film layer on the cathode region to obtain a single capacitor; (2) stacking the single capacitors so that the anode region of each single capacitor is relatively arranged and the cathode region of each single capacitor is relatively arranged. As a result, the laminated solid aluminum electrolytic capacitor prepared by the method according to an embodiment of the present invention has low leakage current, high circuit stability and energy efficiency, less heat generation, avoids heating of the capacitor under high-frequency circuits and the influence on circuit stability, has a high pass rate, a long service life of the capacitor, and high application value. The preparation method is simple to operate, low cost, and suitable for industrial production.

[0058] According to an embodiment of the present invention, step (1) includes: step (1) includes: subjecting the cathode region of the conductive substrate to a first immersion treatment and a first drying treatment in an aqueous solution containing the imidazole ionic liquid, and obtaining a conductive substrate whose cathode region is covered with an ionic liquid layer; the first immersion treatment and the first drying treatment are repeated 5 to 10 times respectively; subjecting the cathode region of the conductive substrate covered with the ionic liquid layer to a second immersion treatment and a second drying treatment in an aqueous solution containing the metal organic framework compound, and obtaining a conductive substrate whose cathode region is sequentially covered with an ionic liquid layer and a metal material layer; the second immersion treatment and the second drying treatment are repeated 5 to 15 times respectively; a non-metallic conductive layer and a metal conductive layer are sequentially formed on the cathode region of the conductive substrate sequentially covered with an ionic liquid layer and a metal material layer to obtain a single capacitor.

[0059] After the first immersion treatment and the first drying treatment, the imidazole ionic liquid can fill the pores of the oxide film layer and form an imidazole ionic liquid layer. After the second immersion treatment and the second drying treatment, a metal material layer is formed on the surface of the imidazole ionic liquid layer.

[0060] According to an embodiment of the present invention, the concentration of the imidazole ionic liquid in the aqueous solution containing the imidazole ionic liquid is 5wt% to 15wt%. In some embodiments, the concentration of the imidazole ionic liquid in the aqueous solution containing the imidazole ionic liquid is 5wt%, 8wt%, 10wt%, 12wt%, 15wt% or a range value formed by any two values ​​as endpoint values. Under this condition, the deposition speed of the imidazole ionic liquid is suitable, and a densely packed imidazole ionic liquid layer can be efficiently formed.

[0061] According to an embodiment of the present invention, the concentration of the metal organic framework compound in the aqueous solution containing the metal organic framework compound is 10wt% to 20wt%. In some embodiments, the concentration of the metal organic framework compound in the aqueous solution containing the metal organic framework compound is 10wt%, 12wt%, 15wt%, 18wt%, 20wt% or a range value formed by any two values ​​as endpoint values. Under this condition, the deposition speed of the metal organic framework compound is suitable, the number of immersions can be reduced, the efficiency is high, the surface of the formed metal material layer is smooth, and the formation of a rough surface that affects the formation of the non-metallic conductive layer is avoided.

[0062] According to an embodiment of the present invention, in step (1), each time the cycle is repeated, the temperature of the first immersion treatment is lower than the temperature of the second immersion treatment, and the temperature of the first drying treatment is lower than the temperature of the second drying treatment. Compared with metal organic framework compounds, the reaction conditions of ionic liquids are milder and the treatment temperature is lower, thereby avoiding damage to the oxide film layer.

[0063] According to an embodiment of the present invention, the temperature of the first immersion treatment is 10°C to 35°C, and the time is 0.5min to 15min. In some embodiments, the temperature of the first immersion treatment is 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, or a range value formed by any two values ​​as endpoint values, and the time is 0.5min, 1min, 5min, 10min, 15min, or a range value formed by any two values ​​as endpoint values. Thus, the ionic liquid can better penetrate into the pores of the oxide film layer, which is helpful for the subsequent formation of the ionic liquid layer.

[0064] According to an embodiment of the present invention, the temperature of the first drying treatment is 80°C to 125°C, and the time is 5min to 50min. In some embodiments, the temperature of the first drying treatment is 80°C, 90°C, 100°C, 110°C, 120°C, 125°C or any two values ​​as a range formed by endpoint values, and the time is 5min, 10min, 15min, 20min, 30min, 40min, 50min or any two values ​​as a range formed by endpoint values. Thus, the ionic liquid layer is better formed.

[0065] According to an embodiment of the present invention, the first dipping treatment and the first drying treatment are repeated 5 to 10 times, respectively. In some embodiments, the first dipping treatment and the first drying treatment are repeated 5, 6, 7, 8, 9 or 10 times, respectively, or any two values ​​are used as the range value formed by the endpoint values.

[0066] According to an embodiment of the present invention, the temperature of the second immersion treatment is 20°C to 40°C, and the time is 3min to 10min. In some embodiments, the temperature of the second immersion treatment is 20°C, 25°C, 30°C, 35°C, 40°C, or a range value formed by any two values ​​as endpoint values, and the time is 3min, 5min, 8min, 10min, or a range value formed by any two values ​​as endpoint values. Thus, a conductive substrate having an ionic liquid layer and a metal material layer sequentially covered in the cathode region can be formed.

[0067] According to an embodiment of the present invention, the temperature of the second drying process is 90°C to 135°C, and the time is 10min to 50min. In some embodiments, the temperature of the second drying process is 90°C, 100°C, 110°C, 120°C, 130°C, 135°C, or a range value formed by any two values ​​as endpoint values, and the time is 10min, 20min, 30min, 40min, 50min, or a range value formed by any two values ​​as endpoint values. Thus, the metal material layer can be better formed.

[0068] According to an embodiment of the present invention, the second dipping treatment and the second drying treatment are repeated 5 to 15 times, respectively. In some embodiments, the second dipping treatment and the second drying treatment are repeated 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 times, respectively, or a range value formed by any two values ​​as endpoint values.

[0069] According to an embodiment of the present invention, before forming an ionic liquid layer on the cathode region of a conductive substrate containing an oxide film layer, it further includes: cutting, assembling, gluing, chemically repairing and surface treating the conductive substrate containing the oxide film layer, which can be specifically operated by conventional technical means in the art.

[0070] It should be noted that the present invention does not strictly limit the manner and specific steps of forming a non-metallic conductive layer and a metal conductive layer on the cathode region of a conductive substrate sequentially covered with an ionic liquid layer and a metal material layer, and can be implemented by conventional technical means in the field of capacitors, such as dipping, pulling, drying and curing. In some embodiments, the cathode region of a conductive substrate sequentially covered with an ionic liquid layer and a metal material layer can be first immersed in a non-metallic slurry, and then the conductive substrate can be pulled out, the excess non-metal can be blown off, and the conductive substrate can be dried and cured after natural drying. The cathode region of the conductive substrate after drying and curing is then immersed in a metal-containing slurry, and then the conductive substrate can be pulled out, the excess metal can be blown off, and the conductive substrate can be dried and cured after natural drying to finally obtain a single capacitor.

[0071] According to an embodiment of the present invention, step (2) comprises: respectively stacking the anode regions of 6 to 16 single capacitors relatively and connecting the anode lead frames, and stacking the cathode regions of the single capacitors relatively and connecting the cathode lead frames, and then extruding and curing to obtain a battery cell; packaging the battery cell in a packaging material, removing the anode lead frame and the cathode lead frame from the packaged capacitor, bending the pins to form a connection structure, and then performing heat treatment, moisture absorption treatment and aging treatment to obtain the stacked solid aluminum electrolytic capacitor.

[0072] It should be noted that the features and advantages described above for the laminated solid aluminum electrolytic capacitor are also applicable to the method for preparing the laminated solid aluminum electrolytic capacitor, and will not be described in detail here.

[0073] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0074] Example 1

[0075] In this embodiment, a laminated solid aluminum electrolytic capacitor is prepared according to the following method:

[0076] 1. Preparation of single capacitor:

[0077] (1) A 6V chemical foil (containing an aluminum oxide film) is punched into the required size, with a length of 0.6 cm and a width of 0.35 cm; a barrier glue is applied on the cut chemical foil to separate the anode area and the cathode area, the glue used is polyimide glue, the length of the cathode area is 5 mm, and the width of the barrier glue is 0.3 mm, and the chemical foil is cured at 150° C. for 30 min; the cathode area of ​​the chemical foil is chemically repaired, and the electrolyte for the chemical repair is an aqueous solution of ammonium adipate with a mass concentration of 10%, the solution temperature is controlled at 80° C., the chemical voltage is controlled at 6 V, and the voltage is maintained for 10 min; the cathode area of ​​the chemically repaired chemical foil is immersed in an aqueous solution of coupling agent KH151 (mass fraction is 2%) at room temperature for 1 min, and after surface treatment, it is naturally dried for 20 min and then dried at a high temperature of 120° C. for 15 min.

[0078] (2) 1,3-dimethylimidazolium chloride ionic liquid (as shown in formula (1)) is prepared into an aqueous solution with a mass fraction of 15 wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the aqueous solution of 1,3-dimethylimidazolium chloride ionic liquid at 20°C for 5 minutes, and dried at 120°C for 40 minutes, and the above operation is repeated 5 times; 2-methylimidazolium zinc metal organic framework material (as shown in formula (2)) is prepared into an aqueous solution with a mass fraction of 10 wt%, and the cathode area of ​​the chemical foil immersed in the above 1,3-dimethylimidazolium chloride ionic liquid is immersed in the aqueous solution of 2-methylimidazolium zinc metal organic framework material at 25°C for 5 minutes, and dried at 130°C for 30 minutes, and the above operation is repeated 6 times.

[0079] (3) dipping the cathode region of the formed foil obtained in step (2) in a conductive graphite slurry having a solid content of 5 wt % and a viscosity of 10 cP for 10 seconds, slowly pulling it out, blowing away excess conductive graphite slurry with an air gun, drying it naturally for 10 min, and then drying it at 100° C. for 25 min to solidify it; applying silver paste on the surface of the cathode region of the formed foil impregnated with conductive graphite by a dipping-pulling method, wherein the silver paste has a solid content of 15 wt % and a viscosity of 120 cP, and drying it at 150° C. for 10 min to solidify it, thereby obtaining a single capacitor.

[0080]

[0081] 2. Preparation of battery cells:

[0082] Eight single capacitors obtained in step (3) were stacked, the anode regions were connected to the lead frame by welding, and the cathode regions were stacked and connected together by conductive silver glue. The cells were extruded and cured at 150° C. for 30 minutes to obtain a compact battery cell.

[0083] 3. Packaging and molding of battery cells:

[0084] The packaging material used for the cell packaging is a low-water-absorbing epoxy resin. The cell with a lead frame is placed in a plastic packaging mold, and the mold is preheated, molded, injected with plasticized epoxy resin, pressure maintained, cooled, molded, and ejected (the injection pressure is 3MPa, the mold temperature is 165°C, and the pressure holding time is 180 seconds) to obtain a packaged product. The packaged capacitor is removed from the lead frame through a rib cutting and molding device, and the pins are bent to form an inner-wrapped pin connection structure to obtain a complete laminated solid aluminum electrolytic capacitor.

[0085] 4. Aging of multilayer solid aluminum electrolytic capacitors:

[0086] First, place the complete laminated solid aluminum electrolytic capacitor in a reflow oven at 260°C for 10 seconds; then perform moisture absorption treatment on the capacitor at a temperature of 85°C, a humidity of 85%, and a moisture absorption time of 8 hours; finally, age the capacitor, first at room temperature and then at high temperature, first boost the voltage to 1.25 times the enabling voltage at room temperature with a boost rate of 0.15V / min, then boost to 0.6 times the enabling voltage and then age at room temperature for 60 minutes and then at 125°C for 180 minutes.

[0087] Example 2

[0088] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0089] The 1,3-dimethylimidazole dimethyl phosphate ionic liquid (as shown in formula (3)) is configured into an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the aqueous solution of the 1,3-dimethylimidazole dimethyl phosphate ionic liquid at 20°C for 5 minutes, and dried at 100°C for 15 minutes, and the above operation is repeated 5 times; the 2-methylimidazole zinc (as shown in formula (2)) metal organic framework material is configured into an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemical foil immersed in the 1,3-dimethylimidazole dimethyl phosphate ionic liquid is immersed in the 2-methylimidazole zinc metal organic framework material aqueous solution at 25°C for 5 minutes, and dried at 120°C for 30 minutes, and the above operation is repeated 6 times.

[0090]

[0091] Example 3

[0092] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0093] The 1-propyl-3-methylimidazolium bromide ionic liquid (as shown in formula (4)) is prepared into an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the aqueous solution of the 1-propyl-3-methylimidazolium bromide ionic liquid at 20°C for 5 minutes, dried at 100°C for 15 minutes, and the above operation is repeated 5 times; the 2-methylimidazolium zinc (as shown in formula (2)) metal organic framework material is prepared into an aqueous solution with a mass fraction of 15wt%, and the cathode area of ​​the chemical foil immersed in the 1-propyl-3-methylimidazolium bromide ionic liquid is immersed in the 2-methylimidazolium zinc metal organic framework material aqueous solution at 25°C for 5 minutes, dried at 120°C for 20 minutes, and the above operation is repeated 6 times.

[0094]

[0095] Example 4

[0096] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0097] The nitro 1,3-dimethylimidazolium ionic liquid (as shown in formula (5)) is prepared into an aqueous solution with a mass fraction of 10 wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the aqueous solution of the nitro 1,3-dimethylimidazolium ionic liquid at 15°C for 10 minutes, dried at 100°C for 15 minutes, and the above operation is repeated 5 times; the 2-methylimidazole cobalt (as shown in formula (6)) metal organic framework material is prepared into an aqueous solution with a mass fraction of 15 wt%, and the cathode area of ​​the chemical foil immersed in the nitro 1,3-dimethylimidazolium ionic liquid is immersed in the 2-methylimidazole cobalt metal organic framework material aqueous solution at 30°C for 5 minutes, dried at 120°C for 20 minutes, and the above operation is repeated 6 times.

[0098]

[0099] Example 5

[0100] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0101] The tetrafluoroborate 1,3-dimethylimidazolium ionic liquid (as shown in formula (7)) is prepared into an aqueous solution with a mass fraction of 10 wt %, and the cathode area of ​​the chemically formed foil obtained in step (1) is immersed in the 15° C. aqueous solution of the tetrafluoroborate 1,3-dimethylimidazolium ionic liquid for 10 min, dried at 100° C. for 15 min, and the above operation is repeated 5 times; the 2-methylimidazolium cobalt (as shown in formula (6)) metal organic framework material is prepared into an aqueous solution with a mass fraction of 15 wt %, and the cathode area of ​​the chemically formed foil immersed in the tetrafluoroborate 1,3-dimethylimidazolium ionic liquid is immersed in the 2-methylimidazolium cobalt metal organic framework material aqueous solution at 30° C. for 10 min, dried at 120° C. for 20 min, and the above operation is repeated 6 times.

[0102]

[0103] Comparative Example 1

[0104] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0105] The cathode area of ​​the chemical foil was immersed in a 20°C 3,4-ethylenedioxythiophene (as shown in formula (8)) monomer solution for 5 minutes, the concentration of the 3,4-ethylenedioxythiophene monomer solution was 15wt%, the chemical foil was taken out and dried at 120°C for 40 minutes, the cathode area of ​​the chemical foil immersed in the 3,4-ethylenedioxythiophene monomer solution was immersed in a 10wt% iron p-toluenesulfonate oxidant solution at a temperature of 25°C for 5 minutes, and then taken out and dried at a temperature of 130°C for 30 minutes. The chemical foil that completed the polymerization reaction was washed with room temperature deionized water for 3 minutes, and then washed with ethanol for 2 minutes, and dried, thereby completing a polymerization cycle. Repeat the above polymerization cycle 6 times.

[0106]

[0107] Comparative Example 2: Only ionic liquid was used in the preparation process

[0108] The method of Example 1 is used to prepare a laminated solid aluminum electrolytic capacitor, except that step 1 (2)

[0109] The details are as follows:

[0110] The 1,3-dimethylimidazolium chloride ionic liquid is configured to be an aqueous solution with a mass fraction of 15wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the 1,3-dimethylimidazolium chloride ionic liquid aqueous solution at 20°C for 5 minutes, and then dried at 120°C for 40 minutes. The above operation is repeated 5 times; the 1,3-dimethylimidazolium chloride ionic liquid is configured to be an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemical foil immersed in the 1,3-dimethylimidazolium chloride ionic liquid is immersed in the 1,3-dimethylimidazolium chloride ionic liquid aqueous solution at 25°C for 5 minutes, and then dried at 130°C for 30 minutes. The above operation is repeated 6 times.

[0111] Comparative Example 3: Only metal organic framework materials were used in the preparation process

[0112] The method of Example 1 is used to prepare a laminated solid aluminum electrolytic capacitor, except that step 1 (2)

[0113] The details are as follows:

[0114] The 2-methylimidazole zinc metal organic framework material is configured into an aqueous solution with a mass fraction of 15wt%, and the cathode area of ​​the chemically formed foil obtained in step (1) is immersed in the 2-methylimidazole zinc aqueous solution at 20°C for 5min. After the chemically formed foil is taken out, it is dried at 120°C for 40min, and the above operation is repeated 5 times; the 2-methylimidazole zinc metal organic framework material is configured into an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemically formed foil immersed in the 2-methylimidazole zinc aqueous solution is immersed in the 2-methylimidazole zinc aqueous solution at 25°C for 5min, and after it is taken out, it is dried at 130°C for 30min, and the above operation is repeated 6 times.

[0115] Comparative Example 4

[0116] The method of Example 1 is used to prepare a laminated solid aluminum electrolytic capacitor, except that step 1 (2)

[0117] The details are as follows:

[0118] Tetrabutylammonium hexafluorophosphate ionic liquid (as shown in formula (9)) is prepared into an aqueous solution with a mass fraction of 15wt%, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the tetrabutylammonium hexafluorophosphate ionic liquid aqueous solution at 20°C for 5 minutes, and then dried at 120°C for 40 minutes, and the above operation is repeated 5 times; 2-methylimidazole zinc metal organic framework material is prepared into an aqueous solution with a mass fraction of 10wt%, and the cathode area of ​​the chemical foil immersed in the tetrabutylammonium hexafluorophosphate ionic liquid is immersed in the 2-methylimidazole zinc metal organic framework material aqueous solution at 25°C for 5 minutes, and then the chemical foil is dried at 130°C for 30 minutes, and the above operation is repeated 6 times.

[0119]

[0120] Comparative Example 5

[0121] The laminated solid aluminum electrolytic capacitor is prepared by the method of Example 1, except that step 1(2) is specifically as follows:

[0122] The 1,3-dimethylimidazolium chloride ionic liquid is prepared into an aqueous solution with a mass fraction of 15 wt %, and the cathode area of ​​the chemical foil obtained in step (1) is immersed in the 1,3-dimethylimidazolium chloride ionic liquid aqueous solution at 20° C. for 5 min, and then dried at 120° C. for 40 min, and the above operation is repeated 5 times; the chromium terephthalate (as shown in formula (10)) metal organic framework material is prepared into an aqueous solution with a mass fraction of 10 wt %, and the cathode area of ​​the chemical foil immersed in the 1,3-dimethylimidazolium chloride ionic liquid is immersed in the chromium terephthalate aqueous solution at 25° C. for 5 min, and then dried at 130° C. for 30 min, and the above operation is repeated 6 times.

[0123]

[0124] Effect example

[0125] The laminated solid aluminum electrolytic capacitors prepared in Examples 1 to 5 and Comparative Examples 1 to 5 were respectively subjected to leakage current tests using a leakage current tester. The test voltage was 6V, the test time was 180 seconds, and the qualified index was that the leakage current did not exceed 10 μA.

[0126] The results are shown in Table 1. It can be seen that when preparing the cathode region, covering the aluminum oxide film layer with an ionic liquid layer and a metal material layer containing a metal organic framework compound can effectively reduce the leakage current, among which Examples 1-5 have better effects. As a result, the qualified rate of the produced capacitors can be improved, that is, the output rate can be improved, which has significant economic and social benefits.

[0127] Table 1 Leakage current test data of multilayer solid aluminum electrolytic capacitor

[0128]

[0129]

[0130] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A laminated solid aluminum electrolytic capacitor, characterized in that: A stacked single capacitor includes an anode region and a cathode region, the anode region of each single capacitor is arranged opposite to each other, and the cathode region of each single capacitor is arranged opposite to each other; The cathode region comprises a conductive substrate comprising an oxide film layer, wherein the oxide film layer is sequentially covered with an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer; The ionic liquid layer includes an ionic liquid; The metal material layer includes a metal organic framework compound.

2. The laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The ionic liquid includes an imidazole ionic liquid; Optionally, the imidazolium ionic liquid has a structure as shown below: Wherein, X1 is selected from methyl, ethyl, propyl, isopropyl, butyl or tert-butyl; X2 is selected from methyl, ethyl, propyl, isopropyl, tert-butyl or cyclohexyl; X3 - Selected from Cl - Br - ,I - 、CH3SO4 - 、CH3CH2SO4 - 、BF4 - 、(CH3)2PO4 - 、(CH3CH2)2PO4 - 、NO3 - or CH3COO - ; Preferably, the imidazolium ionic liquid has a structure as shown in any one of the following:

3. The laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The metal organic framework compound is selected from zeolite imidazolate metal compounds; Preferably, the metal organic framework compound has the structure shown below: Wherein, X4 is selected from Zn or Co.

4. The laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The conductive substrate is selected from chemically formed foil; The oxide film layer includes an aluminum oxide film; The non-metallic conductive layer includes at least one of conductive graphite, graphene, carbon nanotubes, and conductive carbon black, and preferably contains at least conductive graphite; The metal conductive layer includes at least one of copper, silver, silver-coated copper, gold, tin, aluminum, nickel, zinc, and platinum, and preferably contains at least silver.

5. The laminated solid aluminum electrolytic capacitor according to claim 1, characterized in that: The laminated solid aluminum electrolytic capacitor further comprises: An anode pin, to which the anode regions of the stacked monomer capacitors are stacked relatively and connected; A cathode pin, to which the cathode regions of the stacked monomer capacitors are stacked relatively and connected; Packaging material, the packaging material is used to package the stacked single capacitor; The number of the stacked single capacitors is 6 to 16.

6. A method for preparing a laminated solid aluminum electrolytic capacitor according to any one of claims 1 to 5, characterized in that: include: (1) separating an anode region and a cathode region on a conductive substrate containing an oxide film layer, and sequentially forming an ionic liquid layer, a metal material layer, a non-metallic conductive layer and a metal conductive layer covering the oxide film layer on the cathode region to obtain a single capacitor; (2) The single capacitors are stacked so that the anode regions of each single capacitor are arranged opposite to each other and the cathode regions of each single capacitor are arranged opposite to each other.

7. The method according to claim 6, characterized in that Step (1) comprises: The cathode region of the conductive substrate is subjected to a first immersion treatment and a first drying treatment in an aqueous solution containing the imidazole ionic liquid, to obtain a conductive substrate having an ionic liquid layer covering the cathode region; The first dipping treatment and the first drying treatment are repeated 5 to 10 times respectively; The cathode region of the conductive substrate covered with the ionic liquid layer is subjected to a second immersion treatment and a second drying treatment in an aqueous solution containing the metal organic framework compound in a cyclic and repeated manner to obtain a conductive substrate having the cathode region sequentially covered with the ionic liquid layer and the metal material layer; The second dipping treatment and the second drying treatment are repeated 5 to 15 times respectively; A non-metallic conductive layer and a metal conductive layer are sequentially formed on the cathode region of the conductive substrate sequentially covered with the ionic liquid layer and the metal material layer to obtain a single capacitor.

8. The method according to claim 7, characterized in that The concentration of the imidazole ionic liquid in the aqueous solution containing the imidazole ionic liquid is 5wt% to 15wt%; The concentration of the metal organic framework compound in the aqueous solution containing the metal organic framework compound is 10 wt % to 20 wt %.

9. The method according to claim 7, characterized in that: In step (1), each time the cycle is repeated, the temperature of the first immersion treatment is lower than the temperature of the second immersion treatment, and the temperature of the first drying treatment is lower than the temperature of the second drying treatment; Preferably, the temperature of the first immersion treatment is 10°C to 35°C, and the time is 0.5min to 15min; The temperature of the first drying treatment is 80°C to 125°C, and the time is 5min to 50min; The temperature of the second immersion treatment is 20°C to 40°C, and the time is 3min to 10min; The temperature of the second drying treatment is 90° C. to 135° C., and the time is 10 min to 50 min.

10. The method according to claim 6, characterized in that Step (2) comprises: The anode regions of the single capacitors are stacked relatively and connected to the anode lead frame, and the cathode regions of the single capacitors are stacked relatively and connected to the cathode lead frame, and then extruded and solidified to obtain a battery cell; The battery cell is packaged in a packaging material, the anode lead frame and the cathode lead frame are removed from the packaged capacitor, the pins are bent to form a connection structure, and then heat treatment, moisture absorption treatment and aging treatment are performed to obtain the laminated solid aluminum electrolytic capacitor.

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