Solid electrolytic capacitors containing polyaniline

Abstract

This invention provides a solid electrolytic capacitor that exhibits stable electrical characteristics even under environmental changes such as humidity and dryness. [Solution] In the capacitor 100, the capacitor element 120 includes a sintered porous anode, a dielectric disposed on the anode, a precoat disposed on the dielectric, and a solid electrolyte disposed on the precoat. The solid electrolyte includes a conductive polymer having repeating units derived from an aniline monomer having general formula (I). JPEG2026082925000020.jpg2859

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 975,975, filed on 13 February 2020 (which is incorporated herein by reference in its entirety). [Background technology]

[0002] Solid electrolytic capacitors (e.g., tantalum capacitors) are typically manufactured by pressing metal powder (e.g., tantalum) around metal leads, sintering the pressed components, anodizing the sintered anode, and then applying a solid electrolyte. Intrinsically conductive polymers are often used as solid electrolytes due to their advantageous low equivalent series resistance (ESR) and "non-combustion / non-ignition" failure mode. For example, such electrolytes can be formed by in-situ chemical polymerization of 3,4-dioxythiophene monomer (EDOT) in the presence of a catalyst and dopant. However, conventional capacitors using in-situ polymerized polymers have relatively high leakage current (DCL) and tend to fail at high voltages, such as those experienced during fast switching or operating current spikes. In attempts to overcome these problems, dispersions formed from poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) composites (PEDOT:PSS) have also been used. While PEDOT:PSS dispersions can yield improved leakage current values, other problems remain. For example, one problem with polymer slurry-based capacitors is that they can only achieve a relatively small percentage of their wet capacitance, which means they have relatively large capacitance losses and / or fluctuations in the presence of atmospheric humidity. [Overview of the project] [Problems that the invention aims to solve]

[0003] Therefore, there is a need for an improved solid electrolytic capacitor that exhibits relatively stable electrical characteristics.

Means for Solving the Problem

[0004] According to one embodiment of the present invention, a solid electrolytic capacitor including a capacitor element is disclosed. The capacitor element includes a sintered porous anode body, a dielectric disposed on the anode body, a precoat disposed on the dielectric, and a solid electrolyte disposed on the precoat. The solid electrolyte has the following general formula (I):

[0005]

Chemical formula

[0006] Other features and aspects of the present invention are shown in more detail below.

[0007] A complete and practicable disclosure of the present invention, including the best mode of the present invention, directed to those skilled in the art, is shown in more detail in the remainder of this specification with reference to the accompanying drawings.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of a capacitor of the assembly of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of another embodiment of a capacitor of the assembly of the present invention. [Figure 3]Figure 3 is a cross-sectional view of yet another embodiment of the capacitor assembly of the present invention. [Figure 4] Figure 4 is a top view of yet another embodiment of the capacitor assembly of the present invention. [Modes for carrying out the invention]

[0009] The repeated use of reference numerals in this specification and drawings is intended to represent identical or similar features or components of the present invention.

[0010] This discussion describes only representative embodiments and is not intended to limit broader embodiments of the present invention. Those skilled in the art will understand that broader embodiments are embodied within the representative configuration.

[0011] Generally speaking, the present invention relates to a solid electrolytic capacitor comprising a capacitor element including a porous anode, a dielectric disposed on the anode, a precoat disposed on the dielectric, and a solid electrolyte disposed on the precoat. To help facilitate the use of the capacitor in high-voltage applications, the solid electrolyte is provided by the following general formula (I):

[0012] [ka] (In the formula, R5 and R6 are independently hydrogen, alkyl, alkenyl, aryl, alkoxy, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, haloalkyl, amino, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether, ether carboxylate, ether sulfonate, ester sulfonate, urethane, or a combination thereof. The material contains a conductive polymer comprising repeating aniline units. Furthermore, the pre-coat can help stabilize the solid electrolyte, especially at high temperatures.

[0013] While not intended to be limited by theory, such materials are thought to help the resulting capacitors maintain stable electrical properties (e.g., capacitance) under a wide range of different conditions. For example, this capacitor can exhibit a high percentage of its wet capacitance, which allows it to have only small capacitance losses and / or fluctuations in the presence of atmospheric humidity. This performance characteristic is expressed by the formula: Recovery rate (%) = (Dry capacitance / Wet capacitance) × 100 It is quantified by the "capacitance recovery rate" determined by [a specific method / function].

[0014] This capacitor can exhibit a recovery rate of approximately 50% or more, approximately 60% or more in some embodiments, approximately 70% or more in some embodiments, and approximately 80% to 100% in some embodiments.

[0015] Capacitance may also remain stable after exposure to high temperatures, such as above approximately 80°C, approximately 100°C to approximately 150°C in some embodiments, and approximately 105°C to approximately 130°C (e.g., 105°C or 125°C) in some embodiments, for considerable periods of time, such as above approximately 100 hours, and approximately 150 hours to approximately 3,000 hours (e.g., 240 hours) in some embodiments. In one embodiment, for example, the ratio of the capacitance after 240 hours of exposure to a high temperature (e.g., 105°C) to the initial capacitance value (e.g., 23°C) is approximately 0.7 to 1, approximately 0.8 to 1 in some embodiments, approximately 0.9 to 1 in some embodiments, and 0.91 to 0.99 in some embodiments. Actual capacitance values ​​(dry) may vary, but are typically measured at a frequency of 120 Hz and are approximately 1 millifarad / cm² (mF / cm²). 2 ) In some embodiments, the temperature is approximately 2 mF / cm². 2 In some of the above applications, the humidity is approximately 5 to 50 mF / cm². 2 In some embodiments, the humidity is approximately 8 to 20 mF / cm². 2 That is the case.

[0016] This capacitor can also exhibit a relatively high "breakdown voltage" (the voltage at which the capacitor fails), which can be determined, for example, by increasing the applied voltage in 3-volt increments until the leakage current reaches 1 mA, such as approximately 85 volts or more, approximately 90 volts or more in some embodiments, approximately 95 volts or more in some embodiments, and approximately 100 to 300 volts in some embodiments. Furthermore, this capacitor can also withstand relatively high surge currents, which are common in high-voltage applications. The peak surge current may be, for example, approximately 100 amperes or more, approximately 200 amperes or more in some embodiments, and approximately 300 to 800 amperes in some embodiments.

[0017] In addition to the above, this capacitor can also exhibit other improved electrical characteristics. For example, after being subjected to an applied voltage (e.g., 120 volts) for about 30 minutes to about 20 hours, about 1 hour to about 18 hours in some embodiments, and about 4 hours to about 16 hours in some embodiments, this capacitor can exhibit a leakage current (DCL) of only 100 microamperes (μA) or less, about 70 μA or less in some embodiments, and about 1 to about 50 μA in some embodiments. In particular, this capacitor can exhibit such low DCL values ​​even under the dry conditions described above. This capacitor can also exhibit relatively low equivalent series resistance (ESR), measured at an operating frequency of 100 kHz and a temperature of 23°C, such as about 200 milliohms, less than about 150 milliohms in some embodiments, about 0.01 to about 125 milliohms in some embodiments, and about 0.1 to about 100 milliohms in some embodiments. The capacitor can also exhibit such ESR values ​​even after exposure to temperatures above approximately 80°C, approximately 100°C to approximately 150°C in some embodiments, and approximately 105°C to approximately 130°C (e.g., 105°C or 125°C) for a considerable period of time, such as approximately 100 hours or more, and approximately 150 hours to approximately 3,000 hours (e.g., 3,000 hours) in some embodiments. In one embodiment, for example, the ratio of the capacitor's ESR after 3,000 hours of exposure to high temperatures (e.g., 105°C) to the capacitor's initial ESR value (e.g., 23°C) is approximately 2.0 or less, approximately 1.5 or less in some embodiments, and 1.0 to approximately 1.3 in some embodiments.

[0018] Furthermore, it is thought that the capacitor's dissipation factor can be kept at a relatively low level. The dissipation factor generally occurs within the capacitor. This refers to the loss and is usually expressed as a percentage of the ideal capacitor performance. For example, the loss factor of this capacitor is typically about 250% or less at a frequency of 120 Hz, about 200% or less in some embodiments, and about 1% to about 180% in some embodiments.

[0019] Here, various embodiments of the capacitor will be described in more detail.

[0020] I. Capacitor elements A.Anode body The capacitor element includes an anode containing a dielectric formed on a sintered porous body. The porous anode body can be formed from a powder containing valve metal (i.e., a metal that can be oxidized) or valve metal-based compounds, such as tantalum, niobium, aluminum, hafnium, titanium, their alloys, their oxides, or their nitrides. The powder is usually formed from a reduction process in which a tantalum salt (e.g., potassium fluoranthalate (K2TaF7), sodium fluoranthalate (Na2TaF7), tantalum pentachloride (TaCl5), etc.) is reacted with a reducing agent. The reducing agent can be provided in the form of a liquid, a gas (e.g., hydrogen), or a solid, such as a metal (e.g., sodium), a metal alloy, or a metal salt. For example, in one embodiment, a tantalum salt (e.g., TaCl5) can be heated to a temperature of about 900°C to about 2,000°C, in some embodiments about 1,000°C to about 1,800°C, and in some embodiments about 1,100°C to about 1,600°C to form a vapor, which can then be reduced in the presence of a gaseous reducing agent (e.g., hydrogen). Further details of such a reduction reaction are described in WO-2014 / 199480 by Maeshima et al. After reduction, the product can be cooled, pulverized, and washed to form a powder.

[0021] The specific charge of the powder typically varies from about 2,000 to about 600,000 microfarads / volt / gram (μF·V / g) depending on the desired application. For example, in some embodiments, high-charge powders with specific charges of about 100,000 to about 600,000 μF·V / g, in some embodiments, about 120,000 to about 500,000 μF·V / g, and in some embodiments, about 150,000 to about 400,000 μF·V / g can be used. In other embodiments, low-charge powders with specific charges of about 2,000 to about 100,000 μF·V / g, in some embodiments, about 5,000 to about 80,000 μF·V / g, and in some embodiments, about 10,000 to about 70,000 μF·V / g can be used. As is well known in this technology, the charge-to-capacitance ratio can be determined by multiplying the capacitance by the anodizing voltage used and then dividing this product by the weight of the anodized electrode.

[0022] The powder may be a free-flowing fine powder containing primary particles. The primary particles of the powder are generally subjected to ultrasonic vibration for 70 seconds, for example, BECKMAN Determined using a laser particle size distribution analyzer (e.g., LS-230) manufactured by COULTER Corporation, the primary particles have a median diameter (D50) of approximately 5 to approximately 500 nanometers, approximately 10 to approximately 400 nanometers in some embodiments, and approximately 20 to approximately 250 nanometers in some embodiments. The primary particles typically have a three-dimensional particle shape (e.g., spherical or angular). Such particles typically have a relatively low "aspect ratio," i.e., the average diameter or width of the particle divided by the average thickness (D / T). For example, the aspect ratio of the particles may be approximately 4 or less, approximately 3 or less in some embodiments, and approximately 1 to approximately 2 in some embodiments. In addition to the primary particles, the powder may contain other types of particles, such as secondary particles formed by the aggregation (or coagulation) of the primary particles. Such secondary particles may have a median diameter (D50) of approximately 1 to approximately 500 micrometers, and approximately 10 to approximately 250 micrometers in some embodiments.

[0023] Particle aggregation can be achieved by heating the particles and / or by using a binder. For example, aggregation can be achieved at temperatures of approximately 0°C to approximately 40°C, approximately 5°C to approximately 35°C in some embodiments, and approximately 15°C to approximately 30°C in some embodiments. Suitable binders include, for example, poly(vinyl butyral); poly(vinyl acetate); poly(vinyl alcohol); poly(vinylpyrrolidone); cellulose polymers, such as carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, and methylhydroxyethylcellulose; atactic polypropylene, polyethylene; polyethylene glycol (e.g., Carbowax from Dow Chemical Co.); polystyrene, poly(butadiene / styrene); polyamides, polyimides, and polyacrylamides, high molecular weight polyethers; copolymers of ethylene oxide and propylene oxide; fluoropolymers, such as polytetrafluoroethylene, polyvinylidene fluoride, and fluoroolefin copolymers; acrylic polymers, such as sodium polyacrylate, poly(lower alkyl acrylate), poly(lower alkyl methacrylate), and copolymers of lower alkyl acrylate and methacrylate; and fatty acids and waxes, such as stearic acid and other soap fatty acids, vegetable waxes, and microwaxes (purified paraffin).

[0024] The resulting powder can be compressed to form pellets using any conventional powder press equipment. For example, a press molding machine, which is a single-station compression press including a die and one or more punches, can be used. Alternatively, an anvil-type compression press molding machine using only a die and a single downward punch can be used. Single-station compression press molding machines are available in several basic types, such as cam presses, toggle / knuckle presses, and eccentric / crank presses, with various capabilities such as single-action, double-action, floating die, movable platen, opposing ram, screw, impact, hot press, imprinting, or sizing. The powder can be compressed around an anode lead, which may be in the form of a wire, sheet, or the like. The lead can be extended longitudinally from the anode body and can be formed from any conductive material such as tantalum, niobium, aluminum, hafnium, titanium, and their conductive oxides and / or nitrides. The connection of the leads to the anode can also be achieved using other known techniques, for example, by welding the leads to the anode or by embedding them inside the anode during formation (e.g., before compression and / or sintering).

[0025] The binder can be removed after pressing by heating the pellets under vacuum at a constant temperature (e.g., about 150°C to about 500°C) for several minutes. Alternatively, the binder can be removed by contacting the pellets with an aqueous solution, such as described in U.S. Patent No. 6,197,252 by Bishop et al. The pellets are then sintered to form a porous, integral component. The pellets are sintered for about 5 to 100 minutes, and in some embodiments for about 8 to 15 minutes, at a temperature typically about 700°C to about 1800°C, about 800°C to about 1700°C in some embodiments, and about 900°C to about 1400°C in some embodiments. This can be done in one or more steps. If desired, sintering can be carried out in an atmosphere that restricts the movement of oxygen atoms to the anode. For example, sintering can be carried out in a reducing or inert atmosphere such as in a vacuum, in an inert gas, or in hydrogen. The reducing atmosphere may be at a pressure of approximately 10 Torr to approximately 2000 Torr, approximately 100 Torr to approximately 1000 Torr in some embodiments, and approximately 100 Torr to approximately 930 Torr in some embodiments. A mixture of hydrogen and other gases (e.g., argon or nitrogen) may also be used.

[0026] B. Dielectrics Furthermore, the anode is coated with a dielectric. As described above, the dielectric is formed by anodizing the sintered anode such that a dielectric layer is formed on and / or within the anode. For example, a tantalum (Ta) anode can be anodized to tantalum pentoxide (Ta2O5).

[0027] Typically, anodizing is carried out by first applying an electrolyte to the anode, for example, by immersing the anode in the electrolyte. The electrolyte is generally in the form of a liquid, such as a solution (e.g., aqueous or non-aqueous), dispersion, or melt. Solvents such as water (e.g., deionized water); ethers (e.g., diethyl ether, tetrahydrofuran); glycols (e.g., ethylene glycol, propylene glycol, etc.); alcohols (e.g., methanol, ethanol, n-propanol, isopropanol, and butanol); triglycerides; ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone); esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether acetate, and methoxypropyl acetate); amides (e.g., dimethylformamide, dimethylacetamide, dimethylcapryl / caprin fatty acid amide, and N-alkylpyrrolidone); nitriles (e.g., acetonitrile, propionitrile, butyronitrile, and benzonitrile); and sulfoxides or sulfones (e.g., dimethyl sulfoxide (DMSO) and sulfolane) are commonly used in the electrolyte. One or more solvents may constitute about 50% to about 99.9% by weight of the electrolyte, about 75% to about 99% by weight in some embodiments, and about 80% to about 95% by weight in some embodiments. Although not necessarily required, the use of an aqueous solvent (e.g., water) is often desirable to promote oxide formation. In fact, water may constitute about 1% or more by weight of the one or more solvents used in the electrolyte, 10% or more by weight in some embodiments, about 50% or more by weight in some embodiments, about 70% or more by weight in some embodiments, and about 90% to about 100% by weight in some embodiments.

[0028] The electrolyte is conductive and can have a conductivity of 1 millisiemens / cm (mS / cm) or higher at a temperature of 25°C, 30 mS / cm or higher in some embodiments, and about 40 mS / cm to about 100 mS / cm in some embodiments. To increase the conductivity of the electrolyte, ionic compounds that can dissociate in the solvent to form ions are commonly used. Suitable ionic compounds for this purpose include, for example, acids such as nitric acid, sulfuric acid, phosphoric acid, polyphosphate, boric acid, boronic acid; carboxylic acids such as acrylic acid, methacrylic acid, malonic acid, succinic acid, salicylic acid, sulfosalicylic acid, adipic acid, maleic acid, malic acid, oleic acid, gallic acid, tartaric acid, citric acid, formic acid, acetic acid, glycolic acid, oxalic acid, propionic acid, phthalic acid, isophthalic acid, glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, itaconic acid, trifluoroacetic acid, barbituric acid, cinnamic acid, benzoic acid, 4-hydroxybenzoic acid. Examples include organic acids such as aminobenzoic acid; sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, styrenesulfonic acid, naphthalenedisulfonic acid, hydroxybenzenesulfonic acid, dodecylsulfonic acid, and dodecylbenzenesulfonic acid; and polymeric acids such as poly(acrylic) or poly(methacrylic) acids and their copolymers (e.g., malein-acrylic, sulfon-acrylic, and styrene-acrylic copolymers), carrageenan acid, carboxymethylcellulose, and alginic acid. The concentration of the ionic compound is selected to achieve the desired conductivity. For example, an acid (e.g., phosphoric acid) may constitute about 0.01% to about 5% by weight of the electrolyte, about 0.05% to about 0.8% by weight in some embodiments, and about 0.1% to about 0.5% by weight in some embodiments. If desired, a blend of multiple ionic compounds may also be used in the electrolyte.

[0029] To form a dielectric, an electric current is typically passed through the electrolyte while it is in contact with the anode. The thickness of the dielectric layer is controlled by the value of the deposition voltage. For example, a power supply can first be set to constant current mode until the required voltage is reached. Then, the power supply can be set to constant potential mode. The voltage can be switched to ensure that the desired dielectric thickness is formed across the entire surface of the anode. Of course, other known methods such as pulsed or step constant potential methods can also be used. The voltage used for anodizing is typically in the range of about 4 to about 250 V, about 5 to about 200 V in some embodiments, and about 10 to about 150 V in some embodiments. During oxidation, the electrolyte can be maintained at a rising temperature, for example, above about 30°C, about 40°C to about 200°C in some embodiments, and about 50°C to about 100°C in some embodiments. Anodizing can also be carried out below ambient temperature. The resulting dielectric layer can be formed on the surface of the anode and within its pores.

[0030] While not mandatory, in some embodiments, the dielectric layer may have a distinct thickness across the entire anode, having a first portion located on the outer surface of the anode and a second portion located on the inner surface of the anode. In such embodiments, the first portion is selectively formed to be thicker than the second portion. However, it should be understood that the thickness of the dielectric layer does not need to be uniform within a particular region. Some portions of the dielectric layer adjacent to the outer surface may be thinner than, for example, some portions of the layer on the inner surface, and vice versa. Nevertheless, the dielectric layer can be formed such that at least a portion of the layer on the outer surface is thicker than at least a portion on the inner surface. The actual difference in these thicknesses can vary depending on the specific application, but the ratio of the thickness of the first portion to the thickness of the second portion is typically about 1.2 to about 40, about 1.5 to about 25 in some embodiments, and about 2 to about 20 in some embodiments.

[0031] A multi-step method can be used to form dielectric layers having distinct thicknesses. In each step of this process, the sintered anode is anodized to form a dielectric layer (e.g., tantalum pentoxide). In the first step of anodizing, a relatively small anodic voltage, e.g., in the range of about 1 to about 90 volts, about 2 to about 50 volts in some embodiments, and about 5 to about 20 volts in some embodiments, is usually used to ensure that the desired dielectric thickness with respect to the internal region is achieved. The sintered body can then be anodized in the second step of the process to increase the dielectric thickness to a desired level. This is generally achieved by anodizing in an electrolyte at a higher voltage than the voltage used in the first step, e.g., in the range of about 50 to about 350 volts, about 60 to about 300 volts in some embodiments, and about 70 to about 200 volts in some embodiments. During the first and / or second stage, the electrolyte can be maintained at a temperature in the range of about 15°C to about 95°C, about 20°C to about 90°C in some embodiments, and about 25°C to about 85°C in some embodiments.

[0032] The electrolytes used in the first and second stages of the anodizing process may be the same or different. However, typically, the electrolyte used in at least one stage of the dielectric growth process contains the ionic compounds described above. In one particular embodiment, it may be desirable that the electrolyte used in the second stage has a lower ionic conductivity than the electrolyte used in the first stage in order to prevent a substantial amount of oxide film from forming on the inner surface of the anode. In this regard, the electrolyte used in the first stage may contain an ionic compound that is an acid, such as nitric acid, sulfuric acid, phosphoric acid, polyphosphate, boric acid, or boronic acid. Such an electrolyte may have a conductivity of about 0.1 to about 100 mS / cm, about 0.2 to about 20 mS / cm in some embodiments, and about 1 to about 10 mS / cm in some embodiments, as determined at a temperature of 25°C. Furthermore, the electrolyte used in the second stage may contain an ionic compound that is a salt of a weak acid so that the hydronium ion concentration increases in the pores as a result of charge passage within the pores. Ion transport or ion diffusion occurs as needed to balance the charge, causing anions of weak acids to move into the pores. As a result, the dominant conductive species (hydronium ions) The concentration of the ions decreases as equilibrium is formed between hydronium ions, acid anions, and non-dissociated acids, leading to the formation of poorly conductive species. The decrease in the concentration of conductive species results in a relatively high voltage drop in the electrolyte, which hinders further anodizing of the interior, while a thicker oxide layer accumulates on the outside for high conversion voltages in a region of continuous high conductivity. Suitable weak salts include, for example, ammonium salts or alkali metal salts (e.g., sodium, potassium, etc.) such as boric acid, boronic acid, acetic acid, oxalic acid, lactic acid, and adipic acid. Particularly preferred salts include sodium tetraborate and ammonium pentaborate. Such electrolytes typically have conductivity of about 0.1 to about 20 mS / cm, about 0.5 to about 10 mS / cm in some embodiments, and about 1 to about 5 mS / cm in some embodiments, as measured at a temperature of 25°C.

[0033] If desired, each step of the anodizing process can be repeated one or more times to achieve the desired dielectric thickness. Furthermore, the anode may be rinsed or washed with another solvent (e.g., water) after the first and / or second step to remove the electrolyte.

[0034] C. Precoat As shown above, a precoat can also be used, which is placed on the dielectric and positioned between the dielectric and the solid electrolyte. The precoat may consist of one or more layers and may be formed from various different materials. In one embodiment, for example, the precoat may be made of the following general formula (II):

[0035] [ka] (In the formula, Z is an organometallic atom such as silicon or titanium; R1, R2, and R3 are independently alkyl (e.g., methyl, ethyl, propyl, etc.) or hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, etc.), and at least one of R1, R2, and R3 is a hydroxyalkyl; n is an integer between 0 and 8, in some embodiments between 1 and 6, and in some embodiments between 2 and 4 (e.g., 3); X is an organic or inorganic functional group such as glycidyl, glycidyloxy, mercapto, amino, vinyl, etc. This may include organometallic compounds such as compounds having the properties of [specific compound name].

[0036] In some embodiments, at least one of R1, R2, and R3 in formula (II) may be a hydroxyalkyl group (e.g., OCH3). For example, each of R1, R2, and R3 may be a hydroxyalkyl group. However, in other embodiments, R1 may be an alkyl group (e.g., CH3), and R2 and R3 may be hydroxyalkyl groups (e.g., OCH3).

[0037] In some embodiments, X may be an amino group. Suitable amino-functional organosilane compounds include, for example, the following general formula (III):

[0038] [ka] (In the formula, R1, R2, and R3 are as defined above; R4 and R5 are independently hydrogen, alkyl, independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, or hydroxyalkyl, or N, R4, and R5 form a ring structure (e.g., heteroaryl or heterocyclyl) with one or more additional atoms; Z is an organic group that links a nitrogen atom to a silicon atom, such as alkyl (e.g., ethyl or propyl) or aryl (e.g., phenyl). Examples of monoamine-functionalized silanes having this feature can be given.

[0039] Examples of monoamino-functional organosilane compounds include, for example, primary amine compounds (e.g., 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminobutyltriethoxysilane, m-aminophenyltrimethoxysilane, p-aminophenyltrimethoxysilane, aminophenyltrimethoxysilane, 3-aminopropyltris(methoxy-ethoxy)silane, 11-aminoundecyltriethoxysilane, 2(4-pyridylethyl)triethoxysilane, 2-(trimethoxysilylethyl)pyridine, N-(3-trimethoxysilylpropyl)pyrrole, 3-(m-aminophenoxypropyltrimethoxysilane, aminopropylsilanetriol, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldiisopropylethoxysilane, 3-aminopropyldimethylethoxysilane, etc.); and secondary amine compounds (e.g., N-butylaminopropyltrimethoxysilane, N-ethylaminoisobutyltrimethoxysilane, etc.). Examples include silanes, n-methylaminopropyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, 3-(N-allylamino)propyltrimethoxysilane, cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminopropyltrimethoxysilane, N-ethylaminoisobutylmethyldiethoxysilane, (phenylaminoethyl)methyldiethoxysilane, N-phenylaminomethytrimethoxysilane, N-methylaminopropylmethyldimethoxysilane, etc.); tertiary amine compounds (e.g., bis(2-hydroxyethyl)3-aminopropyltriethoxysilane, diethylaminomethyltriethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, etc.); and combinations thereof. Furthermore, if desired, additional groups may be bonded to the nitrogen atom so that the compound is a quaternary amine-functionalized silane compound.

[0040] The following general formula (IV):

[0041] [ka] (In the formula, R1, R2, R3, R4, and R5 are as defined above; Z1 is an organic group that links a nitrogen atom to a silicon atom, while Z2 is an organic group that links nitrogen atoms to each other, such as alkyl (e.g., ethyl or propyl) or aryl (e.g., phenyl). Diaminofunctional silane compounds having the following properties may also be used. Examples of such diaminofunctional silane compounds include, for example, N-(2-aminoethyl)-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(6-aminohexyl)aminomethyl-triethoxysilane, N-(6-aminohexyl)amino-propyltrimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, (aminoethylaminomethyl)-phenethyltrimethoxysilane, and N-3-[(amino(polypropyleneoxy)]-aminopropyl Examples include pyrtrimethoxysilane, N-(2-aminoethyl)-3-aminopropylsilanetriol, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, (aminoethylamino)-3-isobutyldimethylmethoxysilane, and combinations thereof. Triamino functional compounds such as (3-trimethoxysilylpropyl)-diethylenetrimamine can also be used.

[0042] Of course, as shown above, other functional groups can also be used. For example, in some embodiments, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2,2-dimethoxy-1-thia-2-silacyclopentane, 11-mercaptoundecyltrimethoxysilane, S-(octanoyl)mercaptopropyltriethoxysilane, 2-(2-pyridylethyl)thiopropyl-trimethoxysilane, 2-(4-pyrideyl)thiopropyltrimethoxysilane, 3-thiocyantopropyltrimethoxysilane, 2-(3 Sulfur-functional silane compounds such as -trimethoxysilylpropylthio)-thiophene, mercaptomethylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis[3-(triethoxysilyl)propyl]tetrasulfide, bis[3-(triethoxysilyl)propyl]disulfide, bis[m-(2-triethoxysilylethyl)tolyl]polysulfide, bis[3-(triethoxysilyl)propyl]thiourea, and combinations thereof can be used.

[0043] In addition to or instead of organometallic compounds, the precoat may also include one or more layers comprising an intrinsically conductive polymer having a positive charge positioned on the main chain, which is at least partially compensated for by anions covalently bonded to the polymer. Generally, any variety of intrinsically conductive polymers can be used. For example, the intrinsically conductive polymer may be an intrinsically conductive thiophene polymer containing repeating thiophene units. An example of a suitable intrinsically conductive polymer is given by formula (V):

[0044] [ka] (In the formula, R is (CH2) a -O-(CH2) b -L(wherein L is a bond or HC([CH2] c H) is; a is 0 to 10, 0 to 6 in some embodiments, and 1 to 4 (e.g., 1) in some embodiments; b is 1 to 18, 1 to 10 in some embodiments, and 2 to 6 (e.g., 2, 3, 4, or 5) in some embodiments; c is 0 to 10, 0 to 6 in some embodiments, and 1 to 4 (e.g., 1) in some embodiments; M is an anion such as SO3, C(O)O, BF4, CF3SO3, SbF6, N(SO2CF3)2, C4H3O4, ClO4, etc. X is a cation such as hydrogen, an alkali metal (e.g., lithium, sodium, rubidium, cesium, or potassium), or ammonium. It may have repeating thiophene units.

[0045] In one particular embodiment, M in formula (V) is a sulfonate ion. In formula (V), a is preferably 1, and b is preferably 3 or 4. Furthermore, X is preferably sodium or potassium.

[0046] If desired, the polymer may be a copolymer containing other types of repeating units. In such embodiments, the repeating units of formula (V) typically constitute about 50 mol% or more of the total amount of repeating units in the copolymer, about 75 mol% to about 99 mol% in some embodiments, and about 85 mol% to about 95 mol% in some embodiments. Of course, the polymer may be a homopolymer containing up to 100 mol% of the repeating units of formula (V).

[0047] In another embodiment, the intrinsically conductive polymer is given by the following general formula (VII):

[0048] [ka] (In the formula, a and b are as defined above; R5 is a C1-C6 linear or branched alkyl group (e.g., methyl) or halogen atom (e.g., fluorine) which may be substituted; X is a hydrogen atom, an alkali metal (e.g., Li, Na, or K), NH(R 1 )3 (wherein each R 1 is independently a hydrogen atom or an optionally substituted C1-C6 alkyl group), or HNC5H5) has a repeating thiophene unit.

[0049] Specific examples of thiophene compounds used to form such repeats are described in U.S. Patent No. 9,718,905, for example, 3-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-ethyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1 -Propyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-pentyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-hexyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno [3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopropyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isobutyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopentyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-flu Sodium oro-1-propanesulfonate, potassium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, potassium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid, ammonium 3-[(2,3-dihydrothieno[3,4-b]-[1,4) Examples include triethylammonium dioxin-2-yl)methoxy-1-methyl-1-propanesulfonate and combinations thereof. Each of the exemplified thiophene monomers above is thieno, [3,4-b]-1,4-dioxin-2-methanol and branched sultone compounds can be prepared by known methods (e.g., Journal of Electroanalytical Chemistry, 443, 217-226 (1998)).

[0050] Intrinsically conductive polymers can be formed by various techniques understood by those skilled in the art. In one particular embodiment, for example, a thiophene compound having general formula (V) or (VII) can be polymerized in the presence of an oxidation catalyst. Derivatives of these monomers, such as dimers or trimers of the above compounds, can also be used. The derivatives may consist of the same or different monomer units and can be used in their pure form, as well as in mixtures with each other and / or with the monomers. Oxidized or reduced forms of these precursors can also be used. The amount of oxidation catalyst used in this polymerization reaction is not particularly limited, but may be in the range of 1 to 50 molar times, more preferably 1 to 20 molar times, relative to the number of moles of the thiophene compound used as input material. The oxidation catalyst may be a transition metal salt, such as a salt of an inorganic or organic acid containing ammonium, sodium, gold, iron(III), copper(II), chromium(VI), cerium(IV), manganese(IV), manganese(VII), or ruthenium(III) cations. Particularly preferred transition metal salts include halides (e.g., FeCl3 or HAuCl4); and salts of other inorganic acids (e.g., Fe(ClO4)3, Fe2(SO4)3, (NH4)2S2O8, or Na3Mo). 12 PO 40 Examples include salts of organic acids and inorganic acids containing organic groups. Examples of inorganic acid salts containing organic groups include, for example, C1-C 20 Examples include iron(III) salts of monosulfate esters of alkanols (e.g., iron(III) salt of lauryl sulfate). Furthermore, examples of salts of organic acids include, for example, C1-C20 Iron(III) salts of alkanesulfonic acids (e.g., methane, ethane, propane, butane, or dodecanesulfonic acid); iron(III) salts of aliphatic perfluorosulfonic acids (e.g., trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, or perfluorooctanesulfonic acid); aliphatic C1-C 20 Iron(III) salts of carboxylic acids (e.g., 2-ethylhexylcarboxylic acid); iron(III) salts of aliphatic perfluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); C1-C depending on the case. 20 Examples include iron(III) salts of aromatic sulfonic acids substituted with alkyl groups (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid); iron(III) salts of cycloalkanesulfonic acids (e.g., camphorsulfonic acid); and so on. Mixtures of these salts can also be used.

[0051] Oxidative polymerization is generally carried out in the presence of one or more solvents. Suitable solvents include, for example, water, glycols (e.g., ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, dipropylene glycol, etc.); glycol ethers (e.g., methyl glycol ether, ethyl glycol ether, isopropyl glycol ether, etc.); alcohols (e.g., methanol, ethanol, n-propanol, iso-propanol, and butanol); ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone); esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether acetate, methoxypropyl acetate, ethylene carbonate, propylene carbonate, etc.); amides (e.g., dimethylformamide, dimethylacetamide, dimethylcapryl / caprin fatty acid amide, and N-alkylpyrrolidone); sulfoxides or sulfones (e.g., dimethyl sulfoxide (DMSO) and sulfolane); and phenolic compounds (e.g., toluene, xylene, etc.). Water is a particularly suitable solvent for the reaction. The amount of solvent used in this polymerization reaction is not particularly limited, however, as long as the thiophene compound used as a material is dissolved in the solvent, preferably 0.1 to 100 times the weight of the thiophene compound added. Preferably, the reaction ratio is 0.1 to 50 times. The temperature at which the reaction takes place is typically between approximately -20°C and 140°C, and in some embodiments between approximately 20°C and 100°C. Once the reaction is complete, any salt impurities can be removed using known purification techniques such as washing with a solvent, reprecipitation, centrifugation, ultrafiltration, dialysis, or ion exchange resin treatment, and combinations thereof.

[0052] Regardless of how they are formed, polymers are considered to have "intrinsic" conductivity insofar as they have a positive charge located on the main chain, which is at least partially compensated by anions covalently bonded to the polymer. Polymers can have relatively high specific conductivity, for example, in a dry state of about 1 siemens / cm (S / cm) or more, about 10 S / cm or more in some embodiments, about 25 S / cm or more in some embodiments, about 40 S / cm or more in some embodiments, and about 50 to about 500 S / cm in some embodiments. As a result of their intrinsic conductivity, polymers do not require the addition of conventional dopants such as polystyrene sulfonic acid. In fact, polymers do not need to contain substantially any such dopants. Nevertheless, it should be understood that dopants can be used in certain embodiments of the present invention. However, if used, the dopant is usually present in the solid electrolyte in an amount of about 5% by weight or less, about 2% by weight or less in some embodiments, and about 1% by weight or less in some embodiments.

[0053] Polymers are also generally highly soluble in water, which makes it easier and more effective to apply them to the anode. Soluble polymers can also be easily impregnated through pores formed by high specific charge powders, resulting in a solid electrolyte having a "film-like" structure that substantially uniformly coats at least a portion of the anode. This improves the quality of the resulting oxide and its surface coating, thereby enhancing the electrical properties of the capacitor.

[0054] The specific method by which one or more of the above materials are incorporated into the precoat may vary as desired. In one embodiment, for example, the precoat may include one or more layers containing the organometallic compounds described above. To apply such layers, the organometallic compounds can be dissolved in an organic solvent and applied to the part as a solution by screen printing, dipping, electrodeposition, spraying, etc. The organic solvent may vary, but is usually an alcohol such as methanol or ethanol. The organometallic compound may constitute about 0.1% to about 10% by weight of the solution, about 0.2% to about 8% by weight in some embodiments, and about 0.5% to about 5% by weight in some embodiments. The solvent may constitute about 90% to about 99.9% by weight of the solution, about 92% to about 99.8% by weight in some embodiments, and about 95% to about 99.5% by weight in some embodiments. After application, the part can then be dried to remove the solvent and form a precoat layer containing the organometallic compounds.

[0055] In another embodiment, the precoat may include one or more layers containing the intrinsically conductive polymer described above. Such layers may be applied in the form of a solvent-containing solution. The concentration of the polymer may vary depending on the desired viscosity and the specific manner in which the layer is applied to the anode. However, typically the polymer constitutes about 0.1 to about 10% by weight of the solution, about 0.4 to about 5% by weight in some embodiments, and about 0.5 to about 4% by weight in some embodiments. Also, one or more solvents may constitute about 90% to about 99.9% by weight of the solution, about 95% to about 99.6% by weight in some embodiments, and about 96% to about 99.5% by weight in some embodiments. Of course, other solvents may be used, but generally water is the primary solvent and it is desirable that the solution be considered a "water" solution. In most embodiments, for example, water constitutes at least about 50% by weight of the one or more solvents used, at least about 75% by weight in some embodiments, and in some embodiments In its morphology, it constitutes approximately 90% to 100% by weight. When used, the solution can be applied to the anode using any known technique such as immersion, casting (e.g., curtain coating, spin coating, etc.), or printing (e.g., gravure printing, offset printing, screen printing, etc.). The resulting conductive polymer layer can be dried and / or washed after application to the anode.

[0056] If desired, the precoat may include a combination of organometallic compounds and intrinsically conductive polymers. Such materials may be blended together in a single layer or applied in the form of separate layers. In one embodiment, for example, the precoat may include one or more first layers disposed on the dielectric and one or more second layers disposed on the first layers. For example, one or more first layers may contain organometallic compounds and one or more second layers may contain intrinsically conductive polymers. Alternatively, one or more first layers may contain intrinsically conductive polymers and one or more second layers may contain organometallic compounds.

[0057] D. Solid electrolyte A solid electrolyte is placed on top of a precoat, which generally functions as the cathode for the capacitor. Typically, the total thickness of the solid electrolyte is about 1 to about 50 μm, and in some embodiments, about 5 to about 20 μm. As shown above, the solid electrolyte is given by the following general formula (I):

[0058] [ka] (In the formula, R5 and R6 independently comprise a conductive polymer having repeating units derived from an aniline monomer, which includes hydrogen, alkyl (e.g., methyl, ethyl, hexyl, octyl, etc.), alkenyl, aryl, alkoxy (e.g., methoxy, ethoxy, etc.), aryloxy (e.g., phenoxy), alkylthioalkyl, alkylaryl, arylalkyl, haloalkyl (e.g., trifluoromethyl), amino, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether, ether carboxylate, ether sulfonate, ester sulfonate, urethane, etc., or a combination thereof). In certain embodiments, for example, R5 and R6 are hydrogen so that the conductive polymer includes repeating units derived from aniline. In other embodiments, one or both of R5 or R6 may be an alkyl group (e.g., methyl) or an alkoxy group (e.g., methoxy). Polyaniline typically has a weight-average molecular weight of approximately 20,000 grams / mol or more, approximately 50,000 to 500,000 grams / mol in some embodiments, and approximately 60,000 to 300,000 grams / mol in some embodiments, as determined by the polystyrene conversion value measured by gel permeation chromatography.

[0059] Aniline polymers derived from monomers of formula (I) are generally considered to be "extrinsically" conductive, in that they typically require the presence of a dopant. In some embodiments, for example, the aniline monomer can be polymerized in a composition that also includes a proton donor, the proton donor can therefore act as an internal dopant of the polymer. Such proton donors are typically present in amounts of about 0.1 to about 0.5 moles per mole of aniline monomer, and in some embodiments, about 0.3 to about 0.4 moles. 5 moles are used, and in some embodiments, about 0.3 to about 0.4 moles. Suitable proton donors include, for example, Brønsted acids or salts thereof, and in particular organic acids and / or salts thereof. In one embodiment, for example, the proton donor is given by the following general formula (VIII):

[0060] [ka] (In the formula, m is an integer between 1 and 10 (for example, 1 or 2); M is hydrogen; organic free radicals such as aromatic compounds (e.g., pyridium, imidazolium, anilinium, etc.); inorganic free radicals such as alkali metals (e.g., lithium, sodium, potassium, etc.), alkaline earth metals (e.g., calcium, magnesium, etc.), transition metals (e.g., iron), ammonium, etc.; and others. X is SO3 - , PO3 2- , PO4(OH) - OPO3 2- OPO2(OH) - COO - Anions such as; R 4 , R 5 , and R 6 These are, independently, hydrogen; linear or branched C1-C 24 hydrocarbon groups such as alkyl (e.g., octyl or 2-ethylhexyl), cycloalkyl, aryl (e.g., pentyl), alkylaryl, etc.; or R 9 3Si- group (in the formula, R 9 Each of these is independently a hydrogen atom or a hydrocarbon group; R 7 and R 8 These are independently linear or branched C1-C 24 hydrocarbon groups such as alkyl (e.g., butyl, octyl, decyl, or 2-ethylhexyl), cycloalkyl, aryl (e.g., pentyl), alkylaryl; or -(R 10 O) q -R 11 (In the formula, q is an integer greater than or equal to 1 (for example, 1 to 10), R 10 R is a hydrocarbon group or a silylene group, 11 (is hydrogen, a hydrocarbon group), or R 12 3Si-(wherein, R 12 (Each of these is an independent hydrocarbon group.) It may be an organic acid compound having the following properties.

[0061] In one particular embodiment, for example, X could be SO3, and R 4 It can be hydrogen, R 5 is hydrogen and / or R 6 R can be hydrogen. In such embodiments, R 7 and / or R 8 For example, butyl, octyl, decyl, or 2-ethylhexyl are linear or branched C1-C12 molecules. 24 It can be an alkyl group. For example, one particularly suitable proton donor is sodium di-2-ethylhexyl sulfosuccinate.

[0062] Conductive polymers can be formed by various techniques as understood by those skilled in the art. In one particular embodiment, for example, polyaniline derived from general formula (I) can be polymerized in a composition comprising an oxidation catalyst. For example, derivatives of these monomers, which are dimers or trimers of the above compounds, can also be used. The derivatives may consist of the same or different monomer units and can be used in their pure form, as well as in mixtures with each other and / or with the monomers. Oxidized or reduced forms of these precursors can also be used. The amount of oxidation catalyst used in this polymerization reaction is not particularly limited, but may be in the range of 1 to 50 molar times, more preferably 1 to 20 molar times, relative to the number of moles of aniline monomer used as input material. The oxidation catalyst may be a transition metal salt as described above.

[0063] In addition to monomers and other optional components (e.g., proton donors, catalysts, etc.), the polymerization composition typically also includes one or more solvents, such as those described in U.S. Patent No. 9,754,697 (which is incorporated herein by reference in its entirety). Suitable solvents include, for example, water, glycols (e.g., ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, dipropylene glycol, etc.); glycol ethers (e.g., methyl glycol ether, ethyl glycol ether, isopropyl glycol ether, etc.); alcohols (e.g., methanol, ethanol, n-propanol, iso-propanol, and butanol); ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone); esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether acetate, methoxypropyl acetate, ethylene carbonate, propylene carbonate, etc.); amides (e.g., dimethylformamide, dimethylacetamide, dimethylcapryl / caprin fatty acid amide, and N-alkylpyrrolidone); sulfoxides or sulfones (e.g., dimethyl sulfoxide (DMSO) and sulfolane); and phenolic compounds (e.g., toluene, xylene, etc.). In some cases, multiple solvents such as water and organic solvents (e.g., toluene) can be used. The amount of solvent used in this polymerization reaction is not particularly limited, however, it is preferably 0.1 to 100 times, more preferably 0.1 to 50 times, the weight of the aniline monomer added, as long as the aniline monomer used as a material is dissolved in the solvent. The temperature at which the reaction takes place is usually about -20°C to about 140°C, and in some embodiments, it varies from about 20°C to about 100°C. Once the reaction is complete, any salt impurities can be removed using known purification techniques such as washing with solvent, reprecipitation, centrifugation, ultrafiltration, dialysis, or ion exchange resin treatment, and combinations thereof.

[0064] Of course, other components can be used in the polymerization composition to enhance the properties of the resulting solid electrolyte. For example, in some embodiments, inorganic acids (e.g., phosphoric acid) can be used. Furthermore, emulsifiers can be used to help minimize the risk of phase inversion during polymerization. Suitable emulsifiers include, for example, ionic and nonionic emulsifiers known in the art.

[0065] As shown above, aniline polymers derived from monomers of formula (I) are generally considered to be "exogenous" conductive in that they usually require the presence of dopants. In addition to, or instead of, the internal dopants discussed above, external dopants that form a complex or composite material with polyaniline after the polyaniline has been formed can also be used in solid electrolytes. An example of such an external dopant is a phenolic compound. When used, such a phenolic compound is usually used in amounts of about 10 to about 60 grams per gram of polyaniline, about 15 to about 50 grams in some embodiments, and about 20 to about 40 grams in some embodiments. Suitable phenolic compounds are those of the following structures (IX), (X), (XI), or (XII):

[0066] [ka] (In the formula, n is an integer between 0 and 5, preferably between 0 and 3 (for example, 0 or 1); R is independent of C1~C 20 (These include alkyl, alkenyl, cycloalkyl, aryl, and alkylaryl compounds.) Examples of hydroxyphenol compounds that have one of these characteristics include:

[0067] Specific examples of hydroxyphenol compounds of formula (IX) include methoxyphenol, ethoxyphenol, propoxyphenol, isopropoxyphenol, butyloxyphenol, isobutyloxyphenol, and tert-butyloxyphenol. Specific examples of hydroxyphenol compounds of formula (X) include hydroxynaphthalene. Specific examples of hydroxyphenol compounds of formula (XI) include cresol, ethylphenol, propylphenol (e.g., 4-isopropylphenol), butylphenol, and pentylphenol (e.g., 4-tert-pentylphenol). Furthermore, specific examples of hydroxyphenol compounds of formula (XII) include 1,6-naphthanediol, 2,6-naphthanediol, and 2,7-naphthanediol.

[0068] If desired, a heat stabilizer may also be used in the solid electrolyte. When used, such a heat stabilizer is typically used in amounts of about 10 to 60 grams per gram of polyaniline, about 15 to 50 grams in some embodiments, and about 20 to 40 grams in some embodiments. Suitable heat stabilizers include, for example, organic acids, inorganic acids, and / or salts thereof. For example, suitable heat stabilizers include alkyl sulfonic acids (e.g., methanesulfonic acid, ethanesulfonic acid, di-2-ethylhexyl sulfonic acid) Examples include organic sulfonic acids such as citric acid and aromatic sulfonic acids (e.g., benzenesulfonic acid, naphthalenesulfonic acid, anthracenesulfonic acid, dodecylbenzenesulfonic acid, anthraquinonesulfonic acid, etc.); organic carboxylic acids such as alkyl carboxylic acids (e.g., undecylenic acid, cyclohexanecarboxylic acid, 2-ethylhexanoic acid, etc.) and aromatic carboxylic acids (e.g., salicylic acid, benzoic acid, naphthoic acid, trimesic acid, etc.); organic phosphoric acids such as alkyl phosphoric acids (e.g., dodecyl phosphoric acid, bis(2-ethylhexyl) hydrogen phosphate, etc.) and aromatic phosphoric acids; organic phosphonic acids such as alkylphosphonic acids and aromatic phosphonic acids (e.g., benzenephosphonic acid, naphthalenephosphonic acid, phenylphosphonic acid, etc.); and salts of any of the above.

[0069] The resulting polyaniline can easily impregnate the pores formed by the high specific charge powder, and as a result, the resulting solid electrolyte has a "film-like" structure that substantially uniformly coats at least a portion of the anode. This improves the quality of the resulting oxide and its surface coating, thereby improving the electrical properties of the capacitor.

[0070] i. Inner layer Solid electrolytes are generally formed from one or more “inner” conductive polymer layers. In this context, the term “inner” refers to one or more layers formed from the same material and superimposed on the dielectric, either directly or via another layer (e.g., an adhesive layer). For example, one or more inner layers typically include polyaniline as described above. In one particular embodiment, one or more inner layers generally do not include other types of conductive polymers and are therefore formed primarily from the polyaniline described herein. More specifically, polyaniline may constitute about 50% by weight or more, about 70% by weight or more in some embodiments, and about 90% by weight or more (e.g., 100% by weight) in one or more inner layers. One or more inner layers may be used. For example, a solid electrolyte typically includes 2 to 30 inner layers (e.g., 4 to 20 in some embodiments, and about 5 to 15 in some embodiments) (e.g., 10 layers).

[0071] One or more inner layers can be applied in the form of a solvent solution. The concentration of polyaniline may vary depending on the desired viscosity and the specific manner in which the layer is applied to the anode. However, typically, polyaniline constitutes about 0.1 to about 10% by weight of the solution, about 0.4 to about 5% by weight in some embodiments, and about 0.5 to about 4% by weight in some embodiments. Also, one or more solvents constitute about 90% to about 99.9% by weight of the solution, about 95% to about 99.6% by weight in some embodiments, and about 96% to about 99.5% by weight in some embodiments. When used, the solution can be applied to the anode using any known technique such as immersion, casting (e.g., curtain coating, spin coating, etc.), printing (e.g., gravure printing, offset printing, screen printing, etc.). The resulting conductive polymer layer can be dried and / or washed after application to the anode.

[0072] ii. Outer layer The solid electrolyte may consist only of an "inner layer" formed from substantially the same material, i.e., polyaniline. However, in other embodiments, the solid electrolyte may also include one or more optional "outer" conductive polymer layers formed from a different material from one or more inner layers and positioned on top of one or more inner layers. For example, one or more outer layers may be formed from other types of polyaniline, or other types of conductive polymers such as polypyrrole, polythiophene, etc. In one particular embodiment, one or more outer layers may constitute about 50% by weight or more of each outer layer, about 70% by weight or more in some embodiments, and about 90% by weight or more in some embodiments (e.g., It is primarily formed from such exogenous conductive polymers, for example, constituting 100% by weight. One or more outer layers can be used. For example, the solid electrolyte may comprise 2 to 30, 4 to 20 in some embodiments, and about 5 to 15 outer layers in some embodiments.

[0073] When used, the outer layer is, for example, the following equation (XIII):

[0074] [ka] (In the formula, R7 is linear or branched C1~C 18 Alkyl groups (e.g., methyl, ethyl, n- or isopropyl, n-, iso-, sec- or tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, etc.); C5~C 12 Cycloalkyl groups (e.g., cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc.); C6~C 14Aryl group (e.g., phenyl, naphthyl); C7~C 18 Aralkyl groups (e.g., benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2-6-, 3-4-, 3,5-xylyl, mesityl, etc.); C1-C4 hydroxyalkyl groups or hydroxyl groups; (q is an integer between 0 and 8, in some embodiments between 0 and 2, and in one embodiment 0.) The polymer may include a thiophene polymer having repeating units of . In one particular embodiment, "q" is 0 and the polymer is poly(3,4-ethylenedioxythiophene). One commercially suitable example of a monomer suitable for forming such a polymer is 3,4-ethylenedioxythiophene, which is available from Heraeus under the name Clevios® M.

[0075] Polymers of formula (XIII) are generally considered to be "extrinsically" conductive in that they require the presence of another counterion that is not covalently bonded to the polymer. The counterion may be a monomer or polymer anion that neutralizes the charge of the conductive polymer. Polymer anions may be anions such as polymer carboxylic acids (e.g., polyacrylic acid, polymethacrylic acid, polymaleic acid, etc.); polymer sulfonic acids (e.g., polystyrene sulfonic acid (PSS), polyvinyl sulfonic acid, etc.). The acid may also be a copolymer, such as a copolymer of vinyl carboxylic acids and vinyl sulfonic acids with other polymerizable monomers such as acrylic acid esters and styrene. Furthermore, suitable monomer anions include, for example, C1-C 20 Alkanesulfonic acids (e.g., dodecanesulfonic acid); aliphatic perfluorosulfonic acids (e.g., trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, or perfluorooctanesulfonic acid); aliphatic C1-C 20 Carboxylic acids (e.g., 2-ethylhexylcarboxylic acid); aliphatic perfluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); depending on the case, C1-C 20 Substituted by an alkyl group Examples of anions include aromatic sulfonic acids (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid); and cycloalkanesulfonic acids (e.g., camphorsulfonic acid, or tetrafluoroborate, hexafluorophosphate, perchlorate, hexafluoroantimonate, hexafluoroarcenate, or hexachloroantimonate). Particularly preferred counteranions are polymer anions such as polymer carboxylic acids or sulfonic acids (e.g., polystyrenesulfonic acid (PSS)). The molecular weight of such polymer anions is typically in the range of about 1,000 to about 2,000,000, and in some embodiments, about 2,000 to about 500,000.

[0076] When used, the exogenous conductive polymer may be preferable in the form of a dispersion of prepolymerized conductive particles. Such particles typically have an average dimension (e.g., diameter) of about 1 to about 100 nanometers, about 2 to about 80 nanometers in some embodiments, and about 4 to about 50 nanometers in some embodiments. The particle diameter can be determined using known techniques such as ultracentrifugation and laser diffraction. The shape of the particles can also vary. In one particular embodiment, for example, the particles are spherical. However, it should be understood that other shapes such as plates, rods, disks, bars, tubes, irregular shapes, etc., are also intended by the present invention. The concentration of particles in the dispersion may vary depending on the desired viscosity of the dispersion and the particular method of applying the dispersion to the capacitor element. However, typically, the particles constitute about 0.1 to about 10% by weight of the dispersion, about 0.4 to about 5% by weight in some embodiments, and about 0.5 to about 4% by weight in some embodiments.

[0077] The dispersion may also contain one or more binders to further enhance the adhesion of the polymer layer and increase the stability of the particles in the dispersion. The binder may be organic, such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl chloride, polyvinyl acetate, polyvinyl butyrate, polyacrylic acid ester, polyacrylamide, polymethacrylate, polymethacrylate, polyacrylonitrile, styrene / acrylic acid ester, vinyl acetate / acrylic acid ester and ethylene / vinyl acetate copolymer, polybutadiene, polyisoprene, polystyrene, polyether, polyester, polycarbonate, polyurethane, polyamide, polyimide, polysulfone, melamine formaldehyde resin, epoxide resin, silicone resin, or cellulose. Crosslinking agents may also be used to increase the adhesive capacity of the binder. Examples of such crosslinking agents include melamine compounds, masked isocyanates, or functional silanes, such as 3-glycidoxypropyltrialkoxysilane, tetraethoxysilane, and tetraethoxysilane hydrolysates, or crosslinkable polymers, such as polyurethanes, polyacrylates, or polyolefins, and may include subsequent crosslinking.

[0078] Furthermore, dispersants can be used to enhance the ability to form layers on the anode. Suitable dispersants include solvents such as aliphatic alcohols (e.g., methanol, ethanol, i-propanol, and butanol), aliphatic ketones (e.g., acetone and methyl ethyl ketone), aliphatic carboxylic acid esters (e.g., ethyl acetate and butyl acetate), aromatic hydrocarbons (e.g., toluene and xylene), aliphatic hydrocarbons (e.g., hexane, heptane, and cyclohexane), chlorinated hydrocarbons (e.g., dichloromethane and dichloroethane), aliphatic nitriles (e.g., acetonitrile), aliphatic sulfoxides and sulfones (e.g., dimethyl sulfoxide and sulfolane), aliphatic carboxylic acid amides (e.g., methylacetamide, dimethylacetamide, and dimethylformamide), aliphatic and aromatic aliphatic ethers (e.g., diethyl ether and anisole), water, and mixtures of any of the above solvents. Water is a particularly suitable dispersant.

[0079] In addition to those mentioned above, other components can also be used in the dispersion. For example, approximately Conventional fillers having dimensions of 10 nanometers to about 100 micrometers, about 50 nanometers to about 50 micrometers in some embodiments, and about 100 nanometers to about 30 micrometers in some embodiments can be used. Examples of such fillers include calcium carbonate, silicate, silica, calcium sulfate or barium, aluminum hydroxide, glass fibers or glass spheres, wood powder, cellulose powder, carbon black, and conductive polymers. Fillers can be introduced into the dispersion in powder form, but they can also be present in other forms such as fibers.

[0080] Surface active substances such as ionic or nonionic surfactants can also be used in the dispersion. Furthermore, adhesives such as organic functional silanes or their hydrolysates, for example, 3-glycidoxypropyltrialkoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or octyltriethoxysilane can be used. The dispersion may also contain ether group-containing compounds (e.g., tetrahydrofuran), lactone group-containing compounds (e.g., γ-butyrolactone or γ-valerolactone), amide or lactam group-containing compounds (e.g., caprolactam, N-methylcaprolactam, N,N-dimethylacetamide, N-methylacetamide, N,N-dimethylformamide (DMF), N-methylformamide, N-methylformanilide, N-methylpyrrolidone (NMP), N-octylpyrrolidone, or pyrrolidone), sulfones, and The material may also contain additives that increase conductivity, such as sulfoxides (e.g., sulfolane (tetramethylene sulfone) or dimethyl sulfoxide (DMSO)), sugars or sugar derivatives (e.g., saccharose, glucose, fructose, or lactose), sugar alcohols (e.g., sorbitol or mannitol), furan derivatives (e.g., 2-furanic acid or 3-furanic acid), or alcohols (e.g., ethylene glycol, glycerol, di- or triethylene glycol).

[0081] The dispersion can be applied using various known techniques such as spin coating, impregnation, pouring, drop application, injection, spraying, doctor blade application, brush application, printing (e.g., inkjet, screen, or pad printing), or immersion. The viscosity of the dispersion is typically about 0.1 to about 100,000 mPa·s (100 sec). -1 (Measured by shear rate), in some embodiments it is about 1 to about 10,000 mPa·s, in some embodiments it is about 10 to about 1,500 mPa·s, and in some embodiments it is about 100 to about 1,000 mPa·s.

[0082] If desired, hydroxyl-functionalized nonionic polymers may also be used in one or more outer layers of the solid electrolyte. The term "hydroxyl-functionalized" generally means that a compound contains at least one hydroxyl functional group, or can have such a functional group in the presence of a solvent. While not intended to be theoretically limiting, it is thought that using hydroxyl-functionalized polymers with a certain molecular weight can minimize the possibility of chemical decomposition at high voltages. For example, the molecular weight of the hydroxyl-functionalized polymer may be about 100 to 10,000 grams / mol, about 200 to 2,000 grams / mol in some embodiments, about 300 to about 1,200 grams / mol in some embodiments, and about 400 to about 800 grams / mol in some embodiments.

[0083] In general, any variety of hydroxy-functional nonionic polymers can be used for this purpose. For example, in one embodiment, the hydroxy-functional polymer is a polyalkylene ether. Examples of polyalkylene ethers include polyalkylene glycols (e.g., polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyepichlorohydrin, etc.), polyoxetanes, polyphenylene ethers, and polyether ketones. Polyalkylene ethers typically have terminal hydroxyl groups. These are primarily linear nonionic polymers having xyl groups. Polyethylene glycol, polypropylene glycol, and polytetramethylene glycol (polytetrahydrofuran) are particularly preferred, and these are produced by polyaddition of ethylene oxide, propylene oxide, or tetrahydrofuran to water. Polyalkylene ethers can be produced from diols or polyols by polycondensation. The diol component can be selected from saturated or unsaturated, branched or unbranched aliphatic dihydroxy compounds or aromatic dihydroxy compounds containing 5 to 36 carbon atoms, such as pentane-1,5-diol, hexane-1,6-diol, neopentyl glycol, bis-(hydroxymethyl)-cyclohexane, bisphenol A, dimeric diols, hydrogenated dimeric diols, or mixtures of the above diols. Furthermore, polyhydric alcohols such as glycerol, di- and polyglycerol, trimethylolpropane, pentaerythritol, or sorbitol can also be used in the polymerization reaction.

[0084] In addition to those described above, other hydroxy-functional nonionic polymers can also be used in the present invention. Some examples of such polymers include, for example, ethoxylated alkylphenols; ethoxylated or propoxylated C6-C 24 Aliphatic alcohol; general formula: CH3-(CH2) 10-16 -(O-C2H4) 1-25 Polyoxyethylene glycol alkyl ethers having an -OH group (e.g., octaethylene glycol monododecyl ether and pentaethylene glycol monododecyl ether); general formula: CH3-(CH2) 10-16 -(O-C3H6) 1-25 -OH-containing polyoxypropylene glycol alkyl ether; general formula: C8H 17 -(C6H4)-(O-C2H4) 1-25 Polyoxyethylene glycol octylphenol ether containing -OH (e.g., Triton® X-100); general formula: C9H 19 -(C6H4)-(O-C2H4) 1-25-OH-containing polyoxyethylene glycol alkylphenol ethers (e.g., nonoxynol-9); C8-C 24 Fatty acid polyoxyethylene glycol esters, for example, polyoxyethylene glycol sorbitan alkyl esters (e.g., polyoxyethylene(20) sorbitan monolaurate, polyoxyethylene(20) sorbitan monopalmitate, polyoxyethylene(20) sorbitan monostearate, polyoxyethylene(20) sorbitan monooleate, PEG-20 methyl glucose distearate, PEG-20 methyl glucose sesquistearate, PEG-80 castor oil, and PEG-20 castor oil, PEG-3 castor oil, PEG-600 dioleate, and PEG-400 dioleate), and polyoxyethylene glycerol alkyl esters (e.g., polyoxyethylene-23 glycerol laurate and polyoxyethylene-20 glycerol stearate); C8~C 24 Examples include polyoxyethylene glycol ethers of fatty acids (e.g., polyoxyethylene-10 cetyl ether, polyoxyethylene-10 stearyl ether, polyoxyethylene-20 cetyl ether, polyoxyethylene-10 oleyl ether, polyoxyethylene-20 oleyl ether, polyoxyethylene-20 isohexadecyl ether, polyoxyethylene-15 tridecyl ether, and polyoxyethylene-6 tridecyl ether); block copolymers of polyethylene glycol and polypropylene glycol (e.g., Poloxamers); and mixtures thereof.

[0085] Hydroxy-functional nonionic polymers can be introduced into the outer layer in various different ways. For example, in some embodiments, the nonionic polymer can be introduced simply into a dispersion of an exogenous conductive polymer. In such embodiments, the concentration of the nonionic polymer in the layer may be about 1% to about 50% by weight, in some embodiments about 5% to about 40% by weight, and in some embodiments about 10% to about 30% by weight. However, in other embodiments, the nonionic polymer can be applied after one or more initial outer layers have been formed. In such embodiments, the technique used to apply the nonionic polymer can vary. For example, the nonionic polymer can be impregnated, immersed, The solution can be applied in liquid form by various methods such as pouring, dripping, injection, spraying, spreading, painting, or printing, for example, inkjet or screen printing. Solvents known to those skilled in the art, such as water, alcohol, or mixtures thereof, can be used in the solution. The concentration of the nonionic polymer in such a solution is typically in the range of about 5% to about 95% by weight of the solution, about 10% to about 70% by weight in some embodiments, and about 15% to about 50% by weight in some embodiments. If desired, such a solution may not generally contain the conductive polymer. For example, the conductive polymer may constitute about 2% by weight or less of the solution, about 1% by weight or less in some embodiments, and about 0.5% by weight or less in some embodiments.

[0086] E External polymer coating If desired, an external polymer coating may be applied to the anode positioned on top of the solid electrolyte. The external polymer coating generally comprises one or more layers formed from conductive polymer particles as described above (e.g., formed from an exogenous conductive polymer). The external coating can further penetrate into the edge regions of the capacitor body to increase adhesion to the dielectric, providing a more mechanically robust component, thereby reducing the equivalent series resistance and leakage current. Generally, since the intention is to improve the coverage of the edges rather than impregnate the interior of the anode body, the particles used in the external coating are typically larger in size than those used in the optional particles used in the solid electrolyte (e.g., in one or more outer layers). For example, the ratio of the average size of the particles used in the external polymer coating to the average size of the particles used in the solid electrolyte is typically about 1.5 to about 30, about 2 to about 20 in some embodiments, and about 5 to about 15 in some embodiments. For example, the particles used in the outer coating may have an average size of about 50 to about 800 nanometers, about 80 to about 600 nanometers in some embodiments, and about 100 to about 500 nanometers in some embodiments.

[0087] In some cases, a crosslinking agent can be used in the external polymer coating to further increase adhesion to the solid electrolyte. Typically, the crosslinking agent is applied before the dispersion used in the external coating. Suitable crosslinking agents are described, for example, in U.S. Patent Publication 2007 / 0064376 by Merker et al., and include, for example, amines (e.g., diamines, triamines, oligomeric amines, polyamines, etc.); salts or compounds of polyvalent metal cations, such as Mg, Al, Ca, Fe, Cr, Mn, Ba, Ti, Co, Ni, Cu, Ru, Ce, or Zn; phosphonium compounds; sulfonium compounds, etc. Particularly preferred examples include, for example, 1,4-diaminocyclohexane, 1,4-bis(aminomethyl)cyclohexane, ethylenediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, N,N-dimethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,4-butanediamine, and mixtures thereof.

[0088] The crosslinking agent is typically applied from a solution or dispersion having a pH of 1 to 10, 2 to 7 in some embodiments, and 3 to 6 in some embodiments, at 25°C. Acidic compounds can be used to help achieve the desired pH level. Examples of solvents or dispersants for the crosslinking agent include water or organic solvents, such as alcohols, ketones, and carboxylic acid esters. The crosslinking agent can be applied to the capacitor body by any known process, such as spin coating, impregnation, casting, dropwise application, spray application, vapor deposition, sputtering, sublimation, knife coating, painting, or printing, such as inkjet, screen, or pad printing. Once applied, the crosslinking agent can be dried before applying the polymer dispersion. This process can then be repeated until the desired thickness is achieved. For example, the total thickness of the entire outer polymer coating, including the layers of crosslinking agent and dispersion, is about 1 to about 50 μm, in some embodiments. The size may be in the range of approximately 2 to 40 μm, and in some embodiments, approximately 5 to 20 μm.

[0089] F. Cathode coating If desired, the capacitor element may also use a cathode coating disposed on top of a solid electrolyte and an external polymer coating. The cathode coating may include a layer of metal particles containing a number of conductive metal particles dispersed within a polymer matrix. The particles typically constitute about 50% to about 99% by weight of the layer, about 60% to about 98% by weight in some embodiments, and about 70% to about 95% by weight in some embodiments, while the polymer matrix typically constitutes about 1% to about 50% by weight of the layer, about 2% to about 40% by weight in some embodiments, and about 5% to about 30% by weight in some embodiments.

[0090] Conductive metal particles can be formed from various different metals such as copper, nickel, silver, zinc, tin, lead, aluminum, molybdenum, titanium, iron, zirconium, magnesium, and alloys thereof. Silver is a particularly suitable conductive metal for use in the layer over which it is applied. The metal particles often have relatively small dimensions, such as an average diameter of about 0.01 to about 50 micrometers, about 0.1 to about 40 micrometers in some embodiments, and about 1 to about 30 micrometers in some embodiments. It should be understood that usually only one layer of metal particles is used, but multiple layers can be used if desired. The total thickness of such one or more layers is in the range of about 1 μm to about 500 μm, about 5 μm to about 200 μm in some embodiments, and about 10 μm to about 100 μm in some embodiments.

[0091] The polymer matrix typically comprises a polymer that may be inherently thermoplastic or thermosetting. However, the polymer is usually selected to contain a relatively small amount of polar groups so that it can act as a barrier against the electromigration of silver ions and to minimize the degree of water adsorption in the cathode coating. In this regard, the inventors have found that vinyl acetal polymers such as polyvinyl butyral and polyvinyl formal are particularly suitable for this purpose. For example, polyvinyl butyral can be formed by reacting polyvinyl alcohol with an aldehyde (e.g., butyraldehyde). Since this reaction is usually incomplete, polyvinyl butyral generally has a residual hydroxyl content. However, by minimizing this content, the polymer can have a lower degree of strongly polar groups (the absence of which leads to a high degree of moisture adsorption and silver ion migration). For example, the residual hydroxyl content in polyvinyl acetal can be about 35 mol% or less, about 30 mol% or less in some embodiments, and about 10 mol% to about 25 mol% in some embodiments. One commercially available example of such a polymer is available from Sekisui Chemical Co., Ltd. under the name "BH-S" (polyvinyl butyral).

[0092] To form the cathode coating, a conductive paste is typically applied to the capacitor in layers on top of the solid electrolyte. Generally, one or more organic solvents are used in the paste. These generally include glycols (e.g., propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, and dipropylene glycol); glycol ethers (e.g., methyl glycol ether, ethyl glycol ether, and isopropyl glycol ether); ethers (e.g., diethyl ether and tetrahydrofuran); alcohols (e.g., benzyl alcohol, methanol, ethanol, n-propanol, iso-propanol, and butanol); triglycerides; ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone); esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether). A variety of different organic solvents can be used, such as cetes and methoxypropyl acetates; amides (e.g., dimethylformamide, dimethylacetamide, dimethylcapryl / caprin fatty acid amide, and N-alkylpyrrolidone); nitriles (e.g., acetonitrile, propionnitrile, butyronitrile, and benzonitrile); sulfoxides or sulfones (e.g., dimethyl sulfoxide (DMSO) and sulfolane); and mixtures thereof. One or more organic solvents typically constitute about 10% to about 70% by weight of the paste, about 20% to about 65% by weight in some embodiments, and about 30% to about 60% by weight in some embodiments. Typically, metal particles constitute about 10% to 60% by weight of the paste, about 20% to 45% by weight in some embodiments, and about 25% to 40% by weight in some embodiments, while the resinous matrix constitutes about 0.1% to 20% by weight of the paste, about 0.2% to 10% by weight in some embodiments, and about 0.5% to 8% by weight in some embodiments.

[0093] The paste may have a relatively low viscosity, which makes it easy to handle and apply to the capacitor element. The viscosity may be in the range of about 50 to about 3,000 centipoise, in some embodiments 100 to about 2,000 centipoise, and in some embodiments about 200 to about 1,000 centipoise, measured using, for example, a Brookfield DV-1 viscometer (cone plate) operating at a speed of 10 rpm and a temperature of 25°C. If desired, the viscosity can be increased or decreased by using thickeners or other viscosity modifiers in the paste. Furthermore, the thickness of the applied paste may be relatively thin, and the desired properties can still be achieved. For example, the thickness of the paste may be about 0.01 to about 50 micrometers, in some embodiments about 0.5 to about 30 micrometers, and in some embodiments about 1 to about 25 micrometers. After application, the metal paste may optionally be dried to remove some components such as organic solvents. For example, drying can be carried out at temperatures of approximately 20°C to 150°C, approximately 50°C to 140°C in some embodiments, and approximately 80°C to 130°C in some embodiments.

[0094] G. Other components: If desired, other layers known in the art may also be included in the capacitor. For example, in some embodiments, a carbon layer (e.g., graphite) can be placed between the solid electrolyte and the silver layer to help further limit contact between the silver layer and the solid electrolyte. Furthermore, a pre-coat layer containing an organometallic compound can be placed on top of the dielectric.

[0095] II. Termination: Once formed, the capacitor element can be terminated, especially when used in surface mount applications. For example, the capacitor can include an anode termination to which the anode lead of the capacitor element is electrically connected, and a cathode termination to which the cathode of the capacitor element is electrically connected. The termination can be formed using any conductive material such as conductive metals (e.g., copper, nickel, silver, nickel, zinc, tin, palladium, lead, copper, aluminum, molybdenum, titanium, iron, zirconium, magnesium, and alloys thereof). Particularly preferred conductive metals include, for example, copper, copper alloys (e.g., copper-zirconium, copper-magnesium, copper-zinc, or copper-iron), nickel, and nickel alloys (e.g., nickel-iron). The thickness of the termination is generally selected to minimize the thickness of the capacitor. For example, the thickness of the termination may be in the range of about 0.05 to about 1 millimeter, about 0.05 to about 0.5 millimeters in some embodiments, and about 0.07 to about 0.2 millimeters. One typical conductive material is a copper-iron alloy metal plate available from Wieland (Germany). If desired, the terminal surface is in accordance with the technology. As is well known, the final components can be electroplated with nickel, silver, gold, tin, etc., to ensure that they can be mounted onto the circuit board. In one particular embodiment, both ends of the terminal are plated with nickel and silver flash, respectively, while the mounting surface is plated with a tin solder layer.

[0096] The terminations can be connected to the capacitor element using any technique known in the art. For example, in one embodiment, a lead frame can be provided that defines the cathode and anode terminations. To attach the electrolytic capacitor element to the lead frame, a conductive adhesive can first be applied to the surface of the cathode termination. The conductive adhesive can, for example, contain conductive metal particles contained in a resin composition. The metal particles may be silver, copper, gold, platinum, nickel, zinc, bismuth, etc. The resin composition can contain a thermosetting resin (e.g., epoxy resin), a curing agent (e.g., acid anhydride), and a coupling agent (e.g., silane coupling agent). A suitable conductive adhesive is described in Osako et al., U.S. Patent Application Publication No. 2006 / 0038304. The conductive adhesive can be applied to the cathode termination using any various techniques. For example, printing techniques can be used for their practical and cost-saving benefits. The anode lead can also be electrically connected to the anode termination using any technique known in the art, such as mechanical welding, laser welding, or conductive adhesive. Once the anode leads are electrically connected to the anode terminals, the conductive adhesive can then be cured to ensure that the electrolytic capacitor element adheres properly to the cathode terminals.

[0097] Prototype Housing Capacitor elements can be incorporated into a housing in various ways. For example, in some embodiments, the capacitor element can be housed in a case, which can then be filled with a resin material, such as a thermosetting resin (e.g., epoxy resin), which can be cured to form a hardened housing. The capacitor element can be surrounded and sealed with the resin material so that at least a portion of the anode and cathode terminations are exposed for mounting on a circuit board. In this sealed state, the capacitor element and the resin material form a single capacitor.

[0098] Of course, in other embodiments, it may be desirable to house the capacitor elements separately within the housing. In this way, the atmosphere of the housing can be selectively controlled to be dry, thereby limiting the degree of moisture that can come into contact with the capacitor elements. For example, the moisture content of the atmosphere (expressed as relative humidity) may be about 10% or less, about 5% or less in some embodiments, about 3% or less in some embodiments, and about 0.001 to about 1% in some embodiments. For example, the atmosphere may be gaseous and contain at least one inert gas such as nitrogen, helium, argon, xenon, neon, krypton, radon, etc., as well as mixtures thereof. Typically, the inert gas constitutes the majority of the atmosphere in the housing, e.g., about 50% to 100% by weight of the atmosphere, about 75% to 100% by weight in some embodiments, and about 90% to 99% by weight in some embodiments. If desired, a relatively small amount of non-inert gas such as carbon dioxide, oxygen, water vapor, etc., may also be used. However, in such cases, the non-inert gas typically constitutes 15% by weight or less of the atmosphere inside the housing, 10% by weight or less in some embodiments, about 5% by weight or less in some embodiments, about 1% by weight or less in some embodiments, and about 0.01% to about 1% by weight in some embodiments.

[0099] The housing can be formed using any variety of different materials such as metal, plastic, and ceramic. For example, in one embodiment, the housing may be made of tantalum, niobium, aluminum, nickel, hafnium, titanium, copper, silver, steel (e.g., stainless steel). The housing includes one or more layers of metal, such as these alloys (e.g., conductive oxides), or composite materials thereof (e.g., metals coated with conductive oxides). In other embodiments, the housing may include one or more layers of ceramic material, such as aluminum nitride, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, glass, or combinations thereof.

[0100] The housing may have any desired shape, such as cylindrical, D-shaped, rectangular, triangular, or prism-shaped. Referring to Figure 1, for example, one embodiment of a capacitor 100 including a housing 122 and a capacitor element 120 is shown. In this particular embodiment, the housing 122 is generally rectangular. Typically, the housing and the capacitor element have the same or similar shapes so that the capacitor element can be easily housed in an internal cavity. For example, in the shown embodiment, both the capacitor element 120 and the housing 122 have a generally rectangular shape.

[0101] If desired, the capacitor of the present invention can exhibit relatively high volumetric efficiency. To facilitate such high efficiency, the capacitor element typically occupies a substantial portion of the volume of the internal cavity of the housing. For example, the capacitor element may occupy about 30% or more by volume of the internal cavity of the housing, about 50% or more by volume in some embodiments, about 60% or more by volume in some embodiments, about 70% or more by volume in some embodiments, about 80% to about 98% by volume in some embodiments, and about 85% to about 97% by volume in some embodiments. For this purpose, the difference between the dimensions of the capacitor element and the dimensions of the internal cavity defined by the housing is usually relatively small.

[0102] Referring to Figure 1, for example, the capacitor element 120 may have a length (excluding the length of the anode lead 6) that is relatively similar to the length of the internal cavity 126 defined by the housing 122. For example, the ratio of the length of the anode to the length of the internal cavity is in the range of about 0.40 to 1.00, about 0.50 to 0.99 in some embodiments, about 0.60 to 0.99 in some embodiments, and about 0.70 to 0.98 in some embodiments. The capacitor element 120 may have a length of about 5 to 10 millimeters, and the internal cavity 126 may have a length of about 6 to 15 millimeters. Similarly, the ratio of the height of the capacitor element 120 (in the z direction) to the height of the internal cavity 126 may be in the range of about 0.40 to 1.00, about 0.50 to 0.99 in some embodiments, about 0.60 to 0.99 in some embodiments, and about 0.70 to 0.98 in some embodiments. The ratio of the width of the capacitor element 120 (in the x-direction) to the width of the internal cavity 126 may also be in the range of about 0.50 to 1.00, about 0.60 to 0.99 in some embodiments, about 0.70 to 0.99 in some embodiments, about 0.80 to 0.98 in some embodiments, and about 0.85 to 0.95 in some embodiments. For example, the width of the capacitor element 120 may be about 2 to 7 millimeters, the width of the internal cavity 126 may be about 3 to 10 millimeters, the height of the capacitor element 120 may be about 0.5 to 2 millimeters, and the width of the internal cavity 126 may be about 0.7 to 6 millimeters.

[0103] While not strictly required, the capacitor element can be mounted in a housing such that the anode and cathode terminations are formed outside the housing for subsequent integration into the circuit. The specific configuration of the terminations can be determined according to the intended application. For example, in one embodiment, the capacitor can be formed to be surface-mountable and also mechanically robust. For instance, the anode lead can be electrically connected to an external surface-mountable anode and cathode termination (e.g., a pad, sheet, plate, frame, etc.). Such terminations can be extended through the housing to connect to the capacitor. The thickness or height of the terminations is generally chosen to minimize the thickness of the capacitor. Example For example, the thickness of the terminal may be in the range of about 0.05 to about 1 millimeter, about 0.05 to about 0.5 millimeters in some embodiments, and about 0.1 to about 0.2 millimeters. If desired, the surface of the terminal can be electroplated with nickel, silver, gold, tin, etc., as known in the art, to ensure that the final component can be mounted on a circuit board. In one particular embodiment, nickel and silver flashes are deposited on one or more terminals, and the mounting surface is also plated with a tin solder layer. In other embodiments, a thin outer metal layer (e.g., gold) is deposited on one or more terminals on a base metal layer (e.g., copper alloy) to further increase conductivity.

[0104] In some embodiments, a connecting member can be used within the internal cavity of the housing to facilitate connection to a mechanically stable form of termination. For example, referring again to Figure 1, the capacitor 100 may include a connecting member 162 formed from a first portion 167 and a second portion 165. The connecting member 162 may be formed from a conductive material similar to that of the external termination. The first portion 167 and the second portion 165 may be a single unit or separate pieces connected either directly or via a further conductive material (e.g., metal). In the embodiments shown, the second portion 165 is provided in a plane generally parallel to the transverse direction (e.g., the y-direction) in which the lead 6 extends. The first portion 167 is "upright" in the sense that it is provided in a plane generally perpendicular to the transverse direction in which the lead 6 extends. In this way, the first portion 167 can restrict the lateral movement of the lead 6, thereby increasing surface contact and mechanical stability during use. If desired, an insulating material 7 (e.g., a Teflon® washer) can be used around the lead 6.

[0105] The first portion 167 may have a mounting area (not shown) connected to the anode lead 6. Such area may have a "U-shape" to further increase surface contact and mechanical stability of the lead 6. Connection of such area to the lead 6 can be achieved using any various known techniques such as welding, laser welding, conductive adhesive, etc. For example, in one particular embodiment, this area is laser-welded to the anode lead 6. However, regardless of the technique selected, the first portion 167 can hold the anode lead 6 in a substantially horizontal orientation to further increase the dimensional stability of the capacitor 100.

[0106] Referring again to Figure 1, an embodiment of the present invention is shown in which a connecting member 162 and a capacitor element 120 are connected to a housing 122 through anode and cathode terminations (127 and 129, respectively). More specifically, the housing 122 in this embodiment includes an outer wall 123 and two opposing side walls 124, with a cavity 126 formed between them for housing the capacitor element 120. The outer wall 123 and the side walls 124 can be formed from one or more layers of metal, plastic, or ceramic material as described above. In this particular embodiment, the anode termination 127 includes a first region 127a located inside the housing 122 and electrically connected to the connecting member 162, and a second region 127b located outside the housing 122 and providing a mounting surface 201. Furthermore, the cathode termination 129 includes a first region 129a located inside the housing 122 and electrically connected to the solid electrolyte of the capacitor element 120, and a second region 129b located outside the housing 122 and providing the mounting surface 203. It should be understood that the entirety of such regions does not need to be located inside or outside the housing.

[0107] In the embodiment shown, the conductive trace 127c extends within the outer wall 123 of the housing, connecting the first region 127a and the second region 127b. Similarly, the conductive trace 129c extends within the outer wall 123 of the housing, connecting the first region 127a and the second region 127b. The conductive traces and / or termination regions may be separate or integrated. In addition to extending through the outer wall of the housing, the traces are located within the outer wall. They can also be placed in other locations, such as on the outside. Of course, the present invention is by no means limited to using conductive traces to form the desired termination.

[0108] Regardless of the specific configuration used, the connection of the terminations 127 and 129 to the capacitor element 120 can be made using any known technique such as welding, laser welding, conductive adhesive, etc. For example, in one particular embodiment, a conductive adhesive 131 is used to connect the second portion 165 of the connecting member 162 to the anode termination 127. Furthermore, a conductive adhesive 133 is used to connect the cathode of the capacitor element 120 to the cathode termination 129.

[0109] In some cases, the polymer restraint member may be positioned in contact with one or more surfaces of the capacitor element, such as the rear, front, top, bottom, one or more sides, or any combination thereof. The polymer restraint member can reduce the possibility of the capacitor element detaching from the housing. In this regard, the polymer restraint member may have some strength that allows it to hold the capacitor element in a relatively fixed position even when subjected to vibrational forces, but not so tough as to crack. For example, the restraint member may have a tensile strength of about 1 to about 150 megapascals (MPa), about 2 to about 100 MPa in some embodiments, about 10 to about 80 MPa in some embodiments, and about 20 to about 70 MPa in some embodiments, measured at a temperature of about 25°C. It is usually desirable that the restraint member is not conductive. Referring again to Figure 1, for example, one embodiment is shown in which a single polymer restraint member 197 is positioned in contact with the top surface 181 and rear surface 177 of the capacitor element 120. Although Figure 1 shows a single restraint member, it should be understood that the same function can be achieved using multiple separate restraint members. In fact, more generally, any number of polymer restraint members can be used to contact any desired surface of the capacitor element. When multiple restraint members are used, they may be in contact with each other or held physically apart. For example, in one embodiment, a second polymer restraint member (not shown) can be used to contact the top surface 181 and the front surface 179 of the capacitor element 120. The first polymer restraint member 197 and the second polymer restraint member (not shown) may or may not be in contact with each other. In yet another embodiment, the polymer restraint members may also be in contact with the bottom surface 183 and / or one or more sides of the capacitor element 120, together with or instead of other surfaces.

[0110] Regardless of how it is implemented, it is generally desirable that the polymer restraint member also be in contact with at least one surface of the housing to facilitate further mechanical stabilization of the capacitor element against potential delamination. For example, the restraint member can be in contact with one or more inner surfaces of side walls, outer walls, lids, etc. For example, in Figure 1, the polymer restraint member 197 is in contact with the inner surface 107 of the side wall 124 and the inner surface 109 of the outer wall 123. Although in contact with the housing, it is desirable that at least a portion of the cavity defined by the housing remains unoccupied to allow an inert gas to flow through the cavity and limit contact between the solid electrolyte and oxygen. For example, at least about 5% of the cavity volume, and in some embodiments about 10% to about 50% of the cavity volume, is typically left unoccupied by the capacitor element and the polymer restraint member.

[0111] Once connected in the desired configuration, the resulting package is hermetically sealed as described above. Referring again to Figure 1, for example, the housing 122 may also include a lid 125 which is placed on the upper surface of the side wall 124 after the capacitor element 120 and polymer restraint member 197 have been placed inside the housing 122. The lid 125 can be formed from ceramic, metal (e.g., iron, copper, nickel, cobalt, etc., and their alloys), plastic, etc. If desired, a sealing member 187 can be placed between the lid 125 and the side wall 124 to facilitate a good seal. For example, in one embodiment, the sealing member may be a glass-metal sealant, a Kovar® ring (Goodfellow Cam). Examples include Ridge, Ltd. The height of the side wall 124 is generally such that the lid 125 does not come into contact with any surface of the capacitor element 120, so as not to contaminate the capacitor element. The polymer restraint member 197 may or may not be in contact with the lid 125. Once positioned in the desired location, the lid 125 is hermetically sealed to the side wall 124 using known techniques such as welding (e.g., resistance welding, laser welding, etc.) or soldering. Hermetically sealing is generally performed in the presence of an inert gas, such as those mentioned above, so that the resulting assembly is substantially free of reactive gases such as oxygen or water vapor.

[0112] The embodiments described are merely illustrative, and it should be understood that various other configurations for hermetically sealing the capacitor element within the housing can be used in the present invention. Referring to Figure 2, for example, another embodiment of a capacitor 200 is shown that uses a housing 222, which includes an outer wall 123 and a lid 225, with a cavity 126 formed between them for housing the capacitor element 120 and a polymer restraint member 197. The lid 225 includes an outer wall 223 integral with at least one side wall 224. For example, in the embodiment shown, two opposing side walls 224 are shown in cross-section. Both outer walls 223 and 123 extend laterally (y-direction), are generally parallel to each other, and are generally parallel to the lateral direction of the anode lead 6. The side wall 224 extends from the outer wall 223 in a longitudinal direction, which is generally perpendicular to the outer wall 123. The distal end 500 of the cover 225 is defined by the outer wall 223, and the proximal end 501 is defined by the lip portion 253 of the side wall 224.

[0113] The lip portion 253 extends laterally from the side wall 224 (which may be generally parallel to the lateral direction of the outer wall 123). The angle between the side wall 224 and the lip portion 253 may vary, but is typically about 60° to about 120°, about 70° to about 110° in some embodiments, and about 80° to about 100° (e.g., about 90°) in some embodiments. The lip portion 253 also defines a peripheral edge portion 251 which may be generally perpendicular to the lateral direction in which the lip portion 253 and the outer wall 123 extend. The peripheral edge portion 251 is located at the end of the outer circumference of the side wall 224 and may be generally coplanar with the edge portion 151 of the outer wall 123. The lip portion 253 can be sealed to the outer wall 123 using any known technique such as welding (e.g., resistance or laser), soldering, or adhesive. For example, in the shown embodiment, a sealing member 287 (such as a glass-metal sealant or Kovar® ring) is used between the components to facilitate their bonding. In any case, using the above-mentioned lip portion enables a more stable connection between components, improving the sealing and mechanical stability of the capacitor.

[0114] Further possible housing structures can be used in the present invention. For example, Figure 3 shows a capacitor 300 having a housing structure similar to that of Figure 2, except that terminal pins 327b and 329b are used as external terminations for the anode and cathode, respectively. More specifically, terminal pin 327a extends through a trace 327c formed within the outer wall 323 and is connected to the anode lead 6 using known techniques (e.g., welding). Pin 327b can be secured using a further section 327a. Furthermore, terminal pin 329b extends through a trace 329c formed within the outer wall 323 and is connected to the cathode by the conductive adhesive 133 described above.

[0115] The embodiments shown in Figures 1-3 discuss only a single capacitor element. However, it should be understood that multiple capacitor elements can also be hermetically sealed within a housing. Multiple capacitor elements can be mounted in the housing using any various different techniques. Referring to Figure 4, for example, one specific embodiment of a capacitor 400 including two capacitor elements is shown and will be described in more detail here. More specifically, the capacitor 400 includes a first capacitor element 420a that is electrically connected to a second capacitor element 420b. In this embodiment, the capacitor elements are arranged such that their main surfaces are in a horizontal configuration; that is, their width (in the x-direction) The main surface of capacitor element 420a, defined by its length (y-direction), is positioned adjacent to the corresponding main surface of capacitor element 420b. Thus, these main surfaces are generally on the same plane. Alternatively, the main surfaces of the capacitor elements may not be on the same plane, but rather positioned perpendicular to each other in a certain direction, such as the z-direction or the x-direction. Of course, the capacitor elements do not need to extend in the same direction.

[0116] The capacitor elements 420a and 420b are housed within a housing 422, which includes an outer wall 423 and side walls 424 and 425 that together define a cavity 426. Although not shown, a lid can be used to cover the upper surfaces of the side walls 424 and 425 and seal the assembly 400 as described above. In some cases, polymer restraint members can be used to facilitate limiting the vibration of the capacitor elements. For example, in Figure 4, separate polymer restraint members 497a and 497b are positioned adjacent to and in contact with the capacitor elements 420a and 420b, respectively. The polymer restraint members 497a and 497b can be positioned in various different locations. Furthermore, one of the restraint members can be eliminated, or additional restraint members can be used. For example, in some embodiments, it may be desirable to use polymer restraint members between the capacitor elements to further improve mechanical stability.

[0117] In addition to the capacitor elements, the capacitor also includes an anode terminal to which the anode leads of each capacitor element are electrically connected, and a cathode terminal to which the cathodes of each capacitor element are electrically connected. Referring again to Figure 4, for example, a plurality of capacitor elements are shown connected in parallel to a common cathode terminal 429. In this particular embodiment, the cathode terminal 429 is first provided in a plane generally parallel to the bottom surface of the capacitor elements and can be electrically contacted with conductive traces (not shown). The capacitor 400 also includes connecting members 427 and 527 connected to the anode leads (407a and 407b, respectively) of the capacitor elements 420a and 420b. More specifically, connecting member 427 includes an upright portion 465 and a planar portion 463 connected to the anode terminal (not shown). Furthermore, connecting member 527 includes an upright portion 565 and a planar portion 563 connected to the anode terminal (not shown). Of course, it should be understood that a wide range of other types of connection mechanisms can also be used. [Examples]

[0118] The present invention can be better understood by referring to the following embodiments.

[0119] Test Procedure Equivalent series resistance (ESR) The equivalent series resistance can be measured using a Keithley 3330 precision LCZ meter with Kelvin leads, with a 2.2-volt DC bias and a 0.5-volt peak-to-peak sinusoidal signal. The operating frequency was 100 kHz, and the temperature was 23°C ± 2°C.

[0120] Loss factor The loss factor can be measured using a Keithley 3330 precision LCZ meter with Kelvin leads, using a 2.2-volt DC bias and a 0.5-volt peak-to-peak sinusoidal signal. The operating frequency may be 120 Hz, and the temperature may be 23°C ± 2°C. Leakage current Leakage current can be measured using a leak tester at a minimum of 60 seconds after a temperature of 23°C ± 2°C and at the rated voltage.

[0121] capacitance To determine the capacitance (wet), the sample can be completely immersed in an aqueous solution of phosphoric acid with a conductivity of 8,600 μS / cm. Then, using a 0.5-volt DC bias and a 0.3-volt peak-to-peak sinusoidal signal, the capacitance can be measured using an Autolab 85429. The operating frequency may be 0.5 Hz, and the temperature may be 23°C ± 2°C. To determine the capacitance (dry), the sample can be dried at 125°C for at least 24 hours, and then the capacitance can be measured using a Keithley 3330 precision LCZ meter with Kelvin leads, using a 2.2-volt DC bias and a 0.5-volt peak-to-peak sinusoidal signal. The operating frequency may be 120 Hz, and the temperature may be 23°C ± 2°C. The "capacitance recovery rate" is given by the formula: Recovery rate (%) = (Dry capacitance / Wet capacitance) × 100 This can be determined by [method].

[0122] Example 1 Anode samples were formed using tantalum powder with a density of 21,000 μFV / g. Tantalum wires were embedded in each anode sample and sintered at 1550°C, resulting in a density of 5.3 g / cm³. 3The pellets were pressed to a density of 1.15 × 1.10 × 0.60 mm. The pellets were anodized to 77.0 volts in a water / phosphoric acid electrolyte with a conductivity of 8.6 mS at a temperature of 85°C to form a dielectric layer. The pellets were again anodized to 150 volts for 25 seconds in a water / boric acid / disodium tetraborate solution with a conductivity of 2.0 mS at a temperature of 30°C to form a thicker oxide layer deposited on the outside. A conductive polymer coating was formed by immersing the anode in an organic solution of polyaniline with a dopant and then drying it at 150°C for 30 minutes. The entire composition was then immersed in a solution containing sulfonic acid and then dried at 150°C for 30 minutes. This process was repeated three times. The components were then immersed in dispersed poly(3,4-ethylenedioxythiophene) with a solid content of 2% and a viscosity of 160 mPa·s. After coating, the components were dried at 125°C for 15 minutes. This process was repeated 14 times. Next, the components were immersed in a graphite dispersion and dried. Finally, the components were immersed in a silver dispersion and dried. In this way, a large number of 1μF / 35V capacitors (400) were fabricated.

[0123] Example 2 A capacitor was formed in the manner described in Example 1, except that two pre-coat layers of organometallic compounds were used when forming a dielectric containing a 0.33% solution of (3-aminopropyl)trimethoxysilane in ethanol. The component was then immersed in a solution of poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butane-sulfonic acid having a solid content of 1.0%. After coating, the component was dried at 125°C for 15 minutes. This process was repeated three times. A conductive polymer coating was formed by immersing the anode in an organic solution of polyaniline containing a dopant and then drying it at 150°C for 30 minutes. The entire composition was then immersed in a solution containing sulfonic acid. Next, the components were dried at 150°C for 30 minutes. This process was repeated three times. After that, the components were immersed in a dispersed poly(3,4-ethylenedioxythiophene) with a solid content of 2% and a viscosity of 160 mPa·s. After coating, the components were dried at 125°C for 15 minutes. This process was repeated 14 times. Next, the components were immersed in a graphite dispersion and dried. Finally, the components were immersed in a silver dispersion and dried. In this way, a large number of 1μF / 35V capacitor components (400) were fabricated.

[0124] The median results for wet and dry capacitance (μF), along with the calculated capacitance recovery rate, are shown in Table 1 below.

[0125] [Table 1] These and other modifications and changes to the present invention can be implemented by those skilled in the art without departing from the spirit and scope of the invention. Furthermore, it should be understood that multiple aspects of the various embodiments can be interchanged, either whole or in part. Moreover, those skilled in the art will recognize that the above description is merely an example and is not intended to limit the invention further described in the appended claims.

Claims

1. Sintered porous anode; A dielectric material placed on the anode; A pre-coat disposed on the dielectric; and Displaced on the aforementioned dielectric, and the following general formula (I): 【Chemistry 1】 (In the formula, R ５ and R ６ (These are independently hydrogen, alkyl, alkenyl, aryl, alkoxy, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, haloalkyl, amino, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether, ether carboxylate, ether sulfonate, ester sulfonate, urethane, or a combination thereof.) A solid electrolyte comprising a conductive polymer having repeating units derived from an aniline monomer, A solid electrolytic capacitor containing a capacitor element.

2. R ５ and R ６ The solid electrolytic capacitor according to claim 1, wherein the hydrogen is hydrogen.

3. The solid electrolytic capacitor according to claim 1, further comprising a proton donor as the solid electrolyte.

4. The solid electrolytic capacitor according to claim 3, wherein the proton donor is an organic acid compound.

5. The aforementioned organic acid compound is defined by the following general formula (VIII): 【Chemistry 2】 (In the formula, m is an integer between 1 and 10; M is hydrogen, an organic free radical, an inorganic free radical, or a combination thereof; X is an anion; R ４ , R ５ , and R ６ are each independently hydrogen, a hydrocarbon group or an R ９ ３ Si-group (wherein each R ９ is independently hydrogen or a hydrocarbon group); R ７ and R ８ These are independently hydrocarbon groups or -(R １０ O) ｑ -R １１ (In the formula, q is an integer greater than or equal to 1, R １０ R is a hydrocarbon group or a silylene group, １１ is hydrogen, hydrocarbon group, or R １２ ３ Si-(wherein, R １２ Each of these is an independent hydrocarbon group. A solid electrolytic capacitor according to claim 4, having the following characteristics.

6. The solid electrolytic capacitor according to claim 5, wherein M is an alkali metal.

7. X is SO ３ The solid electrolytic capacitor according to claim 5.

8. R ４ , R ５ , and R ６ The solid electrolytic capacitor according to claim 5, wherein each of them is hydrogen.

9. R ７ and R ８ These are independently linear or branched C １ ~C ２４ The solid electrolytic capacitor according to claim 5, wherein the capacitor is alkyl.

10. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte further comprises an external dopant.

11. The aforementioned external dopant has the following structure: (IX), (X), (XI), or (XII): 【Transformation 3】 (In the formula, n is an integer between 0 and 5; R is independent of C １ ~C ２０ (Alkyl, alkenyl, cycloalkyl, aryl, alkylaryl, or combinations thereof) The solid electrolytic capacitor according to claim 10, which is a hydroxyphenol compound having one of the above.

12. The aforementioned external dopants include methoxyphenol, ethoxyphenol, propoxyphenol, isopropoxyphenol, butyloxyphenol, isobutyloxyphenol, tert-butyloxyphenol, hydroxynaphthalene, cresol, and ethyl phosphate. A solid electrolytic capacitor according to claim 10, comprising phenol, propylphenol, butylphenol, pentylphenol, 1,6-naphthalenediol, 2,6-naphthalenediol, 2,7-naphthalenediol, or a combination thereof.

13. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte further comprises a thermal stabilizer.

14. The solid electrolytic capacitor according to claim 13, wherein the heat stabilizer contains an organic acid.

15. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte comprises at least one inner layer containing the conductive polymer.

16. The solid electrolytic capacitor according to claim 1, wherein the solid electrolyte includes at least an outer layer.

17. The solid electrolytic capacitor according to claim 16, wherein the outer layer is formed from particles containing a thiophene polymer.

18. The solid electrolytic capacitor according to claim 1, wherein the pre-coat comprises an intrinsically conductive polymer containing repeating thiophene units.

19. The aforementioned intrinsically conductive polymer is given by the following formula (V): 【Chemistry 4】 (In the formula, R is (CH ２ ) ａ -O-(CH ２ ) ｂ -L (wherein L is a bond or HC ([CH ２ ] ｃ H is; a is between 0 and 10; b is between 1 and 18; c is between 0 and 10; M is an anion; X is a cation. The solid electrolytic capacitor according to claim 18, comprising a repeating unit.

20. The aforementioned intrinsic conductive polymer is defined by the following general formula (VII): 【Transformation 5】 (In the formula, a is between 0 and 10; b is between 1 and 18; R ５ C is substituted in some cases. １ ~C ６ Linear or branched alkyl groups or halogen atoms; X is a hydrogen atom, alkali metal, NH(R) １ ) ３ (In the formula, R １ Each of these is independently a hydrogen atom or optionally substituted C １ ~C ６ (It is an alkyl group), or HNC ５ H ５ (is) A solid electrolytic capacitor according to claim 18, comprising repeating thiophene units having the same properties.

21. The solid electrolytic capacitor according to claim 20, wherein a is 1 and b is 3 or 4.

22. R ５ The solid electrolytic capacitor according to claim 20, wherein is methyl.

23. The solid electrolytic capacitor according to claim 20, wherein X is an alkali metal.

24. The thiophene repeating unit is sodium 3-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-ethyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-propyl-1-propane Sodium sulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-pentyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-hexyl-1-propanesulfonate sodium Sodium phosphate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopropyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isobutyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopentyl-1-propane Sodium phosphate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate potassium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid, 3 A solid electrolytic capacitor according to claim 18, formed from -[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate ammonium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate triethylammonium, or a combination thereof.

25. The solid electrolytic capacitor according to claim 18, wherein the intrinsically conductive polymer has a specific conductivity of about 20 S / cm or more.

26. The solid electrolytic capacitor according to claim 1, wherein the pre-coat contains an organometallic compound.

27. The organometallic compound is defined by the following general formula (II): 【Transformation 6】 (In the formula, R １ , R ２ , and R ３ These are independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, or hydroxyalkyl; R ４ and R ５ These are independently hydrogen, alkyl, independently alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, halo, haloalkyl, hydroxyalkyl, or N, R ４ and R ５ It forms a ring structure with one or more additional atoms; Z is an organic group. The solid electrolytic capacitor according to claim 26, wherein the monoamino functional silane has the following properties.

28. The solid electrolytic capacitor according to claim 26, wherein the monoamino-functionalized silane is a primary amine.

29. The solid electrolytic capacitor according to claim 28, wherein the primary amine is 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminobutyltriethoxysilane, m-aminophenyltrimethoxysilane, p-aminophenyltrimethoxysilane, aminophenyltrimethoxysilane, 3-aminopropyltris(methoxy-ethoxy)silane, 11-aminoundecyltriethoxysilane, 2(4-pyridylethyl)triethoxysilane, 2-(trimethoxysilylethyl)pyridine, N-(3-trimethoxysilylpropyl)pyrrole, 3-(m-aminophenoxypropyltrimethoxysilane, aminopropylsilanetriol, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldiisopropylethoxysilane, 3-aminopropyldimethylethoxysilane, or a combination thereof.

30. The solid electrolytic capacitor according to claim 1, wherein the precoat comprises an organometallic compound and an intrinsically conductive polymer.

31. The precoat comprises a first layer containing the organometallic compound and disposed on the dielectric, and further comprises the intrinsically conductive polymer and the first layer The solid electrolytic capacitor according to claim 30, comprising a second layer disposed on top of the above.

32. The solid electrolytic capacitor according to claim 1, further comprising an external polymer coating disposed on the solid electrolyte and containing conductive polymer particles.

33. The solid electrolytic capacitor according to claim 32, wherein the conductive polymer particles in the external polymer coating include a thiophene polymer.

34. The solid electrolytic capacitor according to claim 32, wherein the external polymer coating further comprises a crosslinking agent.

35. The solid electrolytic capacitor according to claim 1, wherein the anode body includes tantalum.

36. The solid electrolytic capacitor according to claim 1, further comprising a cathode coating including a metal particle layer disposed on the solid electrolyte, wherein the metal particle layer includes a plurality of conductive metal particles.

37. The solid electrolytic capacitor according to claim 1, exhibiting a recovery rate of approximately 50% or more.

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