Aluminum electrolytic capacitor electrolyte, preparation method thereof and aluminum electrolytic capacitor

Abstract

The invention provides an aluminum electrolytic capacitor electrolyte, a preparation method thereof and an aluminum electrolytic capacitor, the aluminum electrolytic capacitor electrolyte comprises a hydrogen elimination agent, and the hydrogen elimination agent is selected from aromatic compounds with cyano groups. The aluminum electrolytic capacitor electrolyte provided by the invention has excellent hydrogen elimination capability, can still stably play a hydrogen elimination role under a high-temperature condition, reduces the generation of water vapor, prevents an aluminum foil oxidation film from being degraded, and does not affect the functions of other components in the electrolyte, thereby prolonging the service life of an aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

Description

Technical Field

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

[0002] The electrolyte of aluminum electrolytic capacitors is the core part of aluminum electrolytic capacitors. It plays an important role in providing oxygen ions and repairing the anodic oxide film. Its performance plays a vital role in the life of aluminum electrolytic capacitors. In the late stage of high-temperature load testing, the existing aluminum electrolytic capacitor products have serious electrolyte degradation, serious internal heating of the product, and a large amount of gas that cannot be effectively absorbed, resulting in excessive internal pressure of the product. The internal gas is released from the explosion-proof valve, the product leaks, and the electrolyte gradually dries up, causing the product to fail prematurely. Therefore, the product service life cannot be guaranteed. Summary of the invention

[0003] The present application aims to solve at least one of the problems existing in the prior art to a certain extent. To this end, the present application proposes an aluminum electrolytic capacitor electrolyte, a preparation method thereof, and an aluminum electrolytic capacitor. The aluminum electrolytic capacitor electrolyte has excellent hydrogen removal ability, can still stably perform hydrogen removal under high temperature conditions, reduce water vapor generation, and prevent aluminum foil oxide film degradation, while not affecting the functions of other components in the electrolyte, thereby extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor. The present application can effectively solve the technical problem that the existing aluminum electrolytic capacitor electrolyte generates excessive internal heat under high temperature conditions and the large amount of gas generated cannot be effectively absorbed, which ultimately leads to premature product failure due to leakage.

[0004] In one aspect of the present application, the present application provides an aluminum electrolytic capacitor electrolyte. According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte includes a hydrogen remover, and the hydrogen remover is selected from aromatic compounds having a cyano group.

[0005] According to the aluminum electrolytic capacitor electrolyte of the present application, an aromatic compound having a cyano group is used as a dehydrogenating agent. No water is generated after the dehydrogenating reaction, thereby reducing the moisture content in the electrolyte. Under high temperature conditions, the generation of water vapor can be reduced, thereby reducing the deterioration of the aluminum foil oxide film due to hydration, and other problems. At the same time, the functions of other components in the electrolyte are not affected, thereby extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

[0006] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte may also have the following additional technical features:

[0007] According to an embodiment of the present application, the hydrogen remover comprises

[0008] At least one of .

[0009] According to an embodiment of the present application, based on the total mass of the aluminum electrolytic capacitor electrolyte, the content of the hydrogen remover is 2.5 to 7.5 parts by weight.

[0010] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte further includes: a main solvent and a main solute.

[0011] According to an embodiment of the present application, the main solvent is selected from at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, n-butanol, diethylene glycol, n-octanol, γ-butyrolactone and butyl acetate.

[0012] According to an embodiment of the present application, the main solute is selected from a fatty acid or an ammonium salt thereof having 8 to 12 carbon atoms in the main carbon chain and a side branch.

[0013] According to an embodiment of the present application, the main solute is selected from at least one of 2-isobutyl suberic acid, 2-isopropyl sebacic acid, 2,7-diisobutyl suberic acid, 2,8-diisopropyl azelaic acid, and 2,9-diisopropyl sebacic acid.

[0014] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte includes: 10 to 30 parts by weight of a main solute; 2.5 to 7.5 parts by weight of the hydrogen remover; and the remainder being a main solvent.

[0015] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte further includes at least one of an auxiliary solvent, an auxiliary solute, and an additive.

[0016] According to an embodiment of the present application, the auxiliary solvent is selected from at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monopropyl ether.

[0017] According to an embodiment of the present application, the auxiliary solute is selected from ammonium carboxylate salts having 9 or 10 carbon atoms.

[0018] According to an embodiment of the present application, the auxiliary solute is selected from at least one of ammonium azelaic acid and ammonium sebacate.

[0019] According to an embodiment of the present application, the additive includes at least one of a waterproofing agent and a flash fire enhancer.

[0020] According to an embodiment of the present application, the waterproofing agent is selected from at least one of ammonium phosphate, phosphotungstic acid, phosphoric acid, phosphorous acid, ammonium phosphite, hypophosphorous acid, ammonium hypophosphite, phosphomolybdic acid or ammonium phosphomolybdate.

[0021] According to an embodiment of the present application, the flash enhancer is selected from at least one of polyvinyl alcohol, polypropylene glycol, polypropylene alcohol, polymerized fatty acid, polymerized fatty acid ammonium and nano inorganic oxide.

[0022] According to an embodiment of the present application, the flash enhancer is selected from at least one of nano-silicon dioxide and polymerized fatty acid ammonium.

[0023] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte includes: 5 to 15 parts by weight of the auxiliary solvent; 10 to 30 parts by weight of the main solute; 5 to 10 parts by weight of the auxiliary solute; 2.5 to 7.5 parts by weight of the hydrogen remover; 0.5 to 15 parts by weight of the additive; the remainder is the main solvent; based on 100 parts by weight of the aluminum electrolytic capacitor electrolyte.

[0024] In another aspect of the present application, the present application proposes a method for preparing the aforementioned aluminum electrolytic capacitor electrolyte. According to an embodiment of the present application, the method comprises: mixing the main solvent, the main solute and the hydrogen scavenger to obtain the aluminum electrolytic capacitor electrolyte.

[0025] According to an embodiment of the present application, the method further comprises: mixing the main solvent, the main solute, the hydrogen scavenger, the auxiliary solvent, the auxiliary solute and the additive to obtain the aluminum electrolytic capacitor electrolyte.

[0026] According to an embodiment of the present application, the method further includes: mixing the main solvent and the auxiliary solvent and heating them to a first temperature to obtain a first mixed liquid, and then mixing the obtained first mixed liquid with the auxiliary solute to obtain a second mixed liquid; cooling the second mixed liquid to a second temperature, and then mixing the obtained second mixed liquid with the main solute to obtain a third mixed liquid; heating the third mixed liquid to a third temperature, keeping the temperature constant for a preset time, and then cooling it to a fourth temperature to obtain a fourth mixed liquid, mixing the fourth mixed liquid, a dehydrogenating agent and an additive, and cooling to room temperature to obtain the aluminum electrolytic capacitor electrolyte.

[0027] According to an embodiment of the present application, the first temperature is 110°C to 150°C.

[0028] According to an embodiment of the present application, the second temperature is 70°C to 100°C.

[0029] According to an embodiment of the present application, the third temperature is 100° C. to 150° C., and the preset time is 1 hour to 3 hours.

[0030] According to an embodiment of the present application, the fourth temperature is 40°C to 60°C.

[0031] In another aspect of the present application, the present application provides an aluminum electrolytic capacitor. According to an embodiment of the present application, the aluminum electrolytic capacitor includes the aluminum electrolytic capacitor electrolyte described above or the aluminum electrolytic capacitor electrolyte prepared by the method described above.

[0032] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0034] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0035] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0036] In this document, the terms "include" or "comprising" are open expressions, that is, including the contents specified in the present application but not excluding other contents.

[0037] The present application proposes an aluminum electrolytic capacitor electrolyte, a preparation method thereof, and an aluminum electrolytic capacitor, which will be described in detail below.

[0038] Aluminum electrolytic capacitor electrolyte

[0039] In one aspect of the present application, the present application provides an aluminum electrolytic capacitor electrolyte. According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte includes a hydrogen scavenger, and the hydrogen scavenger is selected from aromatic compounds having a cyano group.

[0040] Adding dehydrogenating agent to the electrolyte of aluminum electrolytic capacitor can effectively absorb the hydrogen generated inside the capacitor through chemical reaction, thereby reducing the increase in internal pressure caused by hydrogen accumulation, preventing capacitor leakage and activation of explosion-proof valve, improving the stability of the capacitor and extending its service life.

[0041] In aluminum electrolytic capacitors, an oxide film is formed on the surface of the aluminum foil. This film is crucial to the performance of the capacitor. It provides the dielectric properties required by the capacitor and protects the aluminum foil from further oxidation. Traditional dehydrogenators are mostly aromatic compounds with nitro groups. The reaction principle is as follows: water is produced during the dehydrogenation reaction, increasing the moisture content in the electrolyte. Under high temperature conditions, the water evaporates into water vapor, increasing the humidity inside the capacitor. When the aluminum foil oxide film is exposed to a high humidity environment, the moisture reacts with the oxide film, which is called hydration. Hydration causes changes in the structure and chemical properties of the oxide film, thereby reducing its dielectric and protective properties, which are specifically manifested in reduced dielectric strength, increased leakage current, unstable capacitor performance, and other problems, ultimately shortening the service life of the capacitor.

[0042]

[0043] The dehydrogenation agent of the present application uses an aromatic compound with a cyano group, and the reaction principle is as follows: no water is generated after the dehydrogenation reaction, which reduces the moisture content in the electrolyte. The generation of water vapor can be reduced under high temperature conditions, thereby reducing the deterioration of the aluminum foil oxide film due to hydration, and other problems. At the same time, it does not affect the functions of other components in the electrolyte, thereby extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

[0044]

[0045] According to an embodiment of the present application, the hydrogen remover comprises

[0046]

[0047] At least one of .

[0048] The above-mentioned dehydrogenation agent does not produce water after the dehydrogenation reaction, which reduces the moisture content in the electrolyte. It can reduce the generation of water vapor under high temperature conditions, thereby reducing the deterioration of the aluminum foil oxide film due to hydration. At the same time, it does not affect the functions of other components in the electrolyte, thereby extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

[0049] In the above compounds, the N atom on the carbon ring has a lone pair of electrons. Compared with when the substituents on the benzene ring are all hydrogen, the electron cloud density around the N atom is shifted, and the electron activity on the N atom orbit is improved, which is beneficial to improving the hydrogen removal ability of the hydrogen remover.

[0050] Therefore, the above-mentioned hydrogen scavenger has a better hydrogen scavenging ability, does not produce water during the hydrogen scavenging process, and does not affect the functions of other components in the electrolyte.

[0051] According to an embodiment of the present application, based on the total mass of the aluminum electrolytic capacitor electrolyte, the content of the dehydrogenating agent is 2.5 to 7.5 parts by weight. In some embodiments, the content of the dehydrogenating agent is 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight, 4.0 parts by weight, 4.5 parts by weight, 5.0 parts by weight, 5.5 parts by weight, 6.0 parts by weight, 6.5 parts by weight, 7.0 parts by weight, and 7.5 parts by weight. As a result, the dehydrogenating agent can efficiently absorb the hydrogen generated internally, especially under high temperature conditions, reduce the internal pressure caused by hydrogen accumulation, avoid capacitor leakage and explosion-proof valve activation, and prevent the aluminum foil oxide film from deteriorating due to hydration, maintain the chemical stability of the electrolyte and the performance of the capacitor, thereby extending the service life of the capacitor.

[0052] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte further includes: a main solvent and a main solute.

[0053] According to an embodiment of the present application, the main solvent is selected from at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, n-butanol, diethylene glycol, n-octanol, γ-butyrolactone and butyl acetate.

[0054] According to an embodiment of the present application, the main solute is selected from fatty acids or ammonium salts thereof having 8 to 12 carbon atoms in the main carbon chain and side branches.

[0055] In some embodiments, the main solute is selected from a fatty acid or its ammonium salt having 8, 9, 10, 11 or 12 carbon atoms on the main carbon chain and a side branch. According to an embodiment of the present application, the main solute is selected from at least one of 2-isobutyl suberic acid, 2-isopropyl sebacic acid, 2,7-diisobutyl suberic acid, 2,8-diisopropyl azelaic acid, and 2,9-diisopropyl sebacic acid. Thus, the dehydrogenating agent and the solute can be dissolved in the solvent to form a uniform system, and the main solvent and the main solute are compatible with the dehydrogenating agent and the internal materials of the aluminum electrolytic capacitor. Thus, the electrolyte has good chemical stability, can still maintain performance under high temperature and voltage fluctuations, while reducing moisture generation and gas escape, and avoiding negative effects on capacitor performance and life.

[0056] According to an embodiment of the present application, the electrolyte of an aluminum electrolytic capacitor includes:

[0057] 10 to 30 parts by weight of the main solute, illustratively 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 25 parts by weight, 28 parts by weight, 30 parts by weight;

[0058] 2.5 to 7.5 parts by weight of a hydrogen scavenger, illustratively 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight, 4.0 parts by weight, 4.5 parts by weight, 5.0 parts by weight, 5.5 parts by weight, 6.0 parts by weight, 6.5 parts by weight, 7.0 parts by weight, 7.5 parts by weight;

[0059] The balance is the main solvent, illustratively 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, or 50 parts by weight, based on 100 parts by weight of the aluminum electrolytic capacitor electrolyte.

[0060] Therefore, both the main solute and the dehydrogenating agent can be dissolved in the main solvent to form a uniform electrolyte, which helps the main solute, the main solvent and the dehydrogenating agent to play their respective roles, thereby further extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

[0061] According to an embodiment of the present application, the aluminum electrolytic capacitor electrolyte further includes at least one of an auxiliary solvent, an auxiliary solute, and an additive.

[0062] According to an embodiment of the present application, the auxiliary solvent is selected from at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monopropyl ether.

[0063] According to an embodiment of the present application, the auxiliary solute is selected from ammonium carboxylates having 9 or 10 carbon atoms.

[0064] According to an embodiment of the present application, the auxiliary solute is selected from at least one of ammonium azelaic acid and ammonium sebacate.

[0065] According to an embodiment of the present application, the additive includes at least one of a waterproofing agent and a flash fire enhancer.

[0066] In this application, auxiliary solvents usually work in conjunction with the main solvent to adjust the properties of the electrolyte. They can change the viscosity of the electrolyte, lower its freezing point, improve the solubility of the electrolyte, or increase the thermal stability of the electrolyte. In certain cases, auxiliary solvents can also promote ion migration, thereby enhancing the performance of capacitor products.

[0067] In this application, the auxiliary solute has the following functions: (1) Improving conductivity: By adding specific auxiliary solutes, the conductivity of the electrolyte can be improved, thereby improving the performance of the capacitor; (2) Stability and life extension: Specific auxiliary solutes can enhance the stability of the electrolyte, prevent it from decomposing under high temperature or long-term use, and help extend the service life of the capacitor. (3) Optimizing electrical performance: Specific auxiliary solutes can help optimize the key parameters of the capacitor, such as ESR (equivalent series resistance) and CV value (capacitance-voltage characteristics), thereby improving the overall performance of the capacitor.

[0068] In the present application, the waterproofing agent can reduce the generation and absorption of water, prevent the degradation of electrolyte performance and the degradation of aluminum foil oxide film caused by water. The flash enhancer can increase the flash point of the electrolyte, enhance the thermal stability of the capacitor, and reduce the risk of failure caused by overheating.

[0069] According to an embodiment of the present application, the waterproofing agent is selected from at least one of ammonium phosphate, phosphotungstic acid, phosphoric acid, phosphorous acid, ammonium phosphite, hypophosphorous acid, ammonium hypophosphite, phosphomolybdic acid or ammonium phosphomolybdate. Thus, the generation and absorption of water can be reduced, and the degradation of electrolyte performance and the degradation of aluminum foil oxide film caused by water can be prevented. In addition, the above-mentioned waterproofing agent has good compatibility with the dehydrogenating agent, and is not prone to chemical reaction, which helps each to better play its corresponding role.

[0070] According to an embodiment of the present application, the flash enhancer is selected from at least one of polyvinyl alcohol, polypropylene glycol, polypropylene alcohol, polymerized fatty acid, polymerized fatty acid ammonium and nano inorganic oxide. Thus, the flash enhancer can increase the flash point of the electrolyte, enhance the thermal stability of the capacitor, and reduce the risk of failure caused by overheating. In addition, the above-mentioned flash enhancer has good compatibility with the hydrogen remover and is not prone to chemical reaction, which helps each to better play its corresponding role.

[0071] According to an embodiment of the present application, the flash enhancer is selected from at least one of nano-silicon dioxide and polymerized fatty acid ammonium.

[0072] According to an embodiment of the present application, the electrolyte of an aluminum electrolytic capacitor includes:

[0073] 5 to 15 parts by weight of an auxiliary solvent, illustratively 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight;

[0074] 10 to 30 parts by weight of the main solute, illustratively 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, 20 parts by weight, 22 parts by weight, 25 parts by weight, 28 parts by weight, 30 parts by weight;

[0075] 5 to 10 parts by weight of an auxiliary solute, illustratively 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight;

[0076] 2.5 to 7.5 parts by weight of a hydrogen scavenger, illustratively 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight, 4.0 parts by weight, 4.5 parts by weight, 5.0 parts by weight, 5.5 parts by weight, 6.0 parts by weight, 6.5 parts by weight, 7.0 parts by weight, 7.5 parts by weight;

[0077] 0.5 to 15 parts by weight of additives, illustratively 0.5 parts by weight, 1 part by weight, 3 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight;

[0078] The balance is the main solvent, illustratively 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, or 50 parts by weight, based on 100 parts by weight of the aluminum electrolytic capacitor electrolyte.

[0079] Therefore, the electrolyte composition of the aluminum electrolytic capacitor meets the above conditions, which is beneficial to reducing heat loss, preventing performance degradation caused by moisture, effectively absorbing hydrogen to reduce internal pressure, improving thermal stability and safety, etc., thereby enhancing the electrochemical properties and thermal stability of the aluminum electrolytic capacitor and extending its service life.

[0080] Method for preparing electrolyte for aluminum electrolytic capacitor

[0081] In another aspect of the present application, the present application proposes a method for preparing an aluminum electrolytic capacitor electrolyte. According to an embodiment of the present application, the method includes: mixing a main solvent, a main solute and a dehydrogenating agent to obtain an aluminum electrolytic capacitor electrolyte. Thus, in the aluminum electrolytic capacitor electrolyte prepared by the method of the present application, the dehydrogenating agent has excellent dehydrogenating ability, and no water is produced after the dehydrogenating reaction, which reduces the water content in the electrolyte. Under high temperature conditions, water vapor production can be reduced, thereby reducing the deterioration of the aluminum foil oxide film due to hydration, and other problems. At the same time, it does not affect the functions of other components in the electrolyte, thereby extending the service life of the aluminum electrolytic capacitor and improving the performance of the aluminum electrolytic capacitor.

[0082] According to an embodiment of the present application, the method further comprises: mixing a main solvent, a main solute, a hydrogen scavenger, an auxiliary solvent, an auxiliary solute and an additive to obtain the aluminum electrolytic capacitor electrolyte.

[0083] According to an embodiment of the present application, the method further comprises:

[0084] The main solvent and the auxiliary solvent are mixed and heated to a first temperature to obtain a first mixed solution, and the obtained first mixed solution is then mixed with an auxiliary solute to obtain a second mixed solution;

[0085] Cooling the second mixed solution to a second temperature, and then mixing the obtained second mixed solution with the main solute to obtain a third mixed solution;

[0086] The third mixed liquid is heated to a third temperature, maintained at a constant temperature for a preset time, and then cooled to a fourth temperature to obtain a fourth mixed liquid;

[0087] The fourth mixed liquid, the hydrogen remover and the additive are mixed and cooled to room temperature to obtain an aluminum electrolytic capacitor electrolyte, which is conducive to rapid dissolution of the materials and formation of a uniform system.

[0088] According to an embodiment of the present application, the first temperature is 110° C. to 150° C. In some embodiments, the first temperature is 110° C., 115° C., 120° C., 125° C., 130° C., 135° C., 140° C., 145° C., 150° C. This helps to quickly mix the main solvent, the auxiliary solvent, and the auxiliary solute.

[0089] According to an embodiment of the present application, the second temperature is 70° C. to 100° C. In some embodiments, the second temperature is 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., or 100° C. Thus, the main solute can be dissolved quickly and its physical and chemical properties can be prevented from being affected by excessively high temperatures.

[0090] According to an embodiment of the present application, the third temperature is 100°C to 150°C, and the preset time is 1h to 3h. In some embodiments, the third temperature is 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, and the preset time is 1h, 1.5h, 2h, 2.5h, 3h. Thus, the third mixed solution is further made to form a uniform system.

[0091] According to an embodiment of the present application, the fourth temperature is 40° C. to 60° C. In some embodiments, the fourth temperature is 40° C., 45° C., 50° C., 55° C., or 60° C. Thus, the hydrogen remover and the additive can be dissolved quickly and the physical and chemical properties thereof can be prevented from being affected by excessively high temperatures.

[0092] It should be noted that the characteristics and advantages described above for the aluminum electrolytic capacitor electrolyte are also applicable to the method for preparing the aluminum electrolytic capacitor electrolyte, and will not be repeated here.

[0093] Aluminum electrolytic capacitors

[0094] In another aspect of the present application, the present application proposes an aluminum electrolytic capacitor. According to an embodiment of the present application, the aluminum electrolytic capacitor includes the aforementioned aluminum electrolytic capacitor electrolyte or the aluminum electrolytic capacitor electrolyte prepared by the aforementioned method. Therefore, the aluminum electrolytic capacitor of the present application has good electrochemical performance and strong stability, especially can maintain its excellent performance under high temperature conditions, and has a long service life.

[0095] It should be noted that the features and advantages described above for the aluminum electrolytic capacitor electrolyte and its preparation method are also applicable to the aluminum electrolytic capacitor and will not be repeated here.

[0096] The scheme of the present application will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are indicated in the embodiments, the technology or conditions described in the literature in this area or the product specification are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially.

[0097] Example 1

[0098] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0099] 1. Formulation

[0100]

[0101] 2. Steps

[0102] The main solvent and the auxiliary solvent are mixed and heated to 130°C, and then the auxiliary solute is added, cooled to 85°C, the main solute is added, and after complete dissolution, it is heated to 130°C, kept at a constant temperature of 130°C for 2h, cooled to 50°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0103] Example 2

[0104] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0105] 1. Formulation

[0106]

[0107]

[0108] 2. Steps

[0109] The main solvent and the auxiliary solvent are mixed and heated to 135°C, and then the auxiliary solute is added, cooled to 90°C, the main solute is added, and after complete dissolution, it is heated to 120°C, kept at a constant temperature of 120°C for 1h, cooled to 45°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0110] Example 3

[0111] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0112] 1. Formulation

[0113]

[0114] 2. Steps

[0115] The main solvent and the auxiliary solvent are mixed and heated to 140°C, and then the auxiliary solute is added, cooled to 80°C, the main solute is added, and after complete dissolution, it is heated to 120°C, kept constant at 120°C for 1.5 hours, cooled to 60°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0116] Example 4

[0117] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0118] 1. Formulation

[0119]

[0120] 2. Steps

[0121] The main solvent and the auxiliary solvent are mixed and heated to 145°C, and then the auxiliary solute is added, cooled to 75°C, the main solute is added, and after complete dissolution, it is heated to 110°C, kept at a constant temperature of 110°C for 2.0h, cooled to 55°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0122] Example 5

[0123] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0124] 1. Formulation

[0125]

[0126]

[0127] 2. Steps

[0128] The main solvent and the auxiliary solvent are mixed and heated to 115°C, and then the auxiliary solute is added, cooled to 70°C, the main solute is added, and after complete dissolution, it is heated to 105°C, kept at a constant temperature of 105°C for 2.5 hours, cooled to 45°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0129] Comparative Example 1

[0130] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0131] 1. Formulation

[0132]

[0133] 2. Steps

[0134] The main solvent and the auxiliary solvent are mixed and heated to 130°C, and then the auxiliary solute is added, cooled to 85°C, the main solute is added, and after complete dissolution, it is heated to 130°C, kept at a constant temperature of 130°C for 2h, cooled to 50°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0135] Comparative Example 2

[0136] In this embodiment, the electrolyte of aluminum electrolytic capacitor is prepared according to the following method:

[0137] 1. Formulation

[0138]

[0139] 2. Steps

[0140] The main solvent and the auxiliary solvent are mixed and heated to 130°C, and then the auxiliary solute is added, cooled to 85°C, the main solute is added, and after complete dissolution, it is heated to 130°C, kept at a constant temperature of 130°C for 2h, cooled to 50°C, the dehydrogenation agent and additives are added, and after complete dissolution, it is cooled to room temperature. The preparation is completed to obtain an aluminum electrolytic capacitor electrolyte.

[0141] Test Case

[0142] 1. The aluminum electrolytic capacitor electrolytes prepared in Examples 1-5 and Comparative Examples 1-2 were used to make 450V 1200μF 35*50 aluminum electrolytic capacitors.

[0143] 2. Conduct a 125°C ripple durability test on aluminum electrolytic capacitors. The specific steps are as follows:

[0144] The aluminum electrolytic capacitors were subjected to a DC + AC load test and a durability test at a high temperature of 125°C; the AC current was 6.5A per aluminum electrolytic capacitor, and the DC voltage + AC voltage = 450V was tested at 120Hz for 1000h, 2000h, 3000h, 4000h, and 5000h respectively. During the experiment, the product heated up, the internal gas expanded, and the bottom explosion-proof valve bulged. The horizontal height tester was used to measure the bulging height (ΔH / mm) of the bottom of the aluminum electrolytic capacitor to compare the hydrogen removal capacity. The specific test results are shown in Table 1.

[0145] Table 1 Aluminum electrolytic capacitor electrolyte hydrogen removal ability test

[0146]

[0147] As can be seen from Table 1, compared with Comparative Example 1 and Comparative Example 2, the aluminum electrolytic capacitors produced by the electrolytes of Examples 1-5 have a significantly lower gas bulging degree, indicating that their gas production is small. This shows that compared with the hydrogen remover with a nitro group, the hydrogen remover with a cyano group has a better hydrogen removal ability, reduced internal heat, improved deterioration of the anodic oxide film, and significantly improved product life. The embodiment using the cyano hydrogen remover has a significant improvement in product life. This is mainly due to the superior performance of the cyano hydrogen remover in reducing gas production, reducing internal heat of the product, and protecting the anodic oxide film.

[0148] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An aluminum electrolytic capacitor electrolyte, characterized in that: The invention comprises a hydrogen scavenger, wherein the hydrogen scavenger is selected from aromatic compounds having a cyano group.

2. The aluminum electrolytic capacitor electrolyte according to claim 1, characterized in that: The hydrogen scavenger comprises At least one of .

3. The aluminum electrolytic capacitor electrolyte according to claim 1, characterized in that: Based on the total mass of the aluminum electrolytic capacitor electrolyte, the content of the hydrogen remover is 2.5 to 7.5 parts by weight.

4. The aluminum electrolytic capacitor electrolyte according to claim 1, characterized in that: Further including: Main solvent and main solute; The main solvent is selected from at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, n-butanol, diethylene glycol, n-octanol, γ-butyrolactone and butyl acetate; The main solute is selected from fatty acids or their ammonium salts having 8 to 12 carbon atoms in the main carbon chain and side branches; Optionally, the main solute is selected from at least one of 2-isobutyl suberic acid, 2-isopropyl sebacic acid, 2,7-diisobutyl suberic acid, 2,8-diisopropyl azelaic acid, and 2,9-diisopropyl sebacic acid; Optionally, the aluminum electrolytic capacitor electrolyte comprises: 10 to 30 parts by weight of a main solute; 2.5 to 7.5 parts by weight of the hydrogen remover; The balance is the main solvent.

5. The aluminum electrolytic capacitor electrolyte according to claim 4, characterized in that: further comprising at least one of an auxiliary solvent, an auxiliary solute, and an additive; The auxiliary solvent is selected from at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monopropyl ether; The auxiliary solute is selected from ammonium carboxylates having 9 or 10 carbon atoms; The additive includes at least one of a waterproofing agent and a flash fire enhancer; Optionally, the auxiliary solute is selected from at least one of ammonium azelate and ammonium sebacate; Optionally, the waterproofing agent is selected from at least one of ammonium phosphate, phosphotungstic acid, phosphoric acid, phosphorous acid, ammonium phosphite, hypophosphorous acid, ammonium hypophosphite, phosphomolybdic acid or ammonium phosphomolybdate; Optionally, the flash enhancer is selected from at least one of polyvinyl alcohol, polypropylene glycol, polypropylene alcohol, polymerized fatty acid, polymerized fatty acid ammonium and nano inorganic oxide; Optionally, the flash enhancer is selected from at least one of nano silicon dioxide and polymerized fatty acid ammonium.

6. The aluminum electrolytic capacitor electrolyte according to claim 5, characterized in that: include: 5 to 15 parts by weight of the auxiliary solvent; 10 to 30 parts by weight of the main solute; 5 to 10 parts by weight of the auxiliary solute; 2.5 to 7.5 parts by weight of the hydrogen remover; 0.5 to 15 parts by weight of the additive; The balance is the main solvent; based on 100 parts by weight of the aluminum electrolytic capacitor electrolyte.

7. A method for preparing the electrolyte of an aluminum electrolytic capacitor according to any one of claims 1 to 6, characterized in that: include: The main solvent, the main solute and the hydrogen scavenger are mixed to obtain the aluminum electrolytic capacitor electrolyte.

8. The method according to claim 7, characterized in that Further including: The main solvent, the main solute, the hydrogen scavenger, the auxiliary solvent, the auxiliary solute and the additive are mixed to obtain the aluminum electrolytic capacitor electrolyte; Optionally, the method further comprises: The main solvent and the auxiliary solvent are mixed and heated to a first temperature to obtain a first mixed solution, and the obtained first mixed solution is then mixed with the auxiliary solute to obtain a second mixed solution; Cooling the second mixed liquid to a second temperature, and then mixing the obtained second mixed liquid with the main solute to obtain a third mixed liquid; The third mixed liquid is heated to a third temperature, maintained at a constant temperature for a preset time, and then cooled to a fourth temperature to obtain a fourth mixed liquid; The fourth mixed liquid, the hydrogen scavenger and the additive are mixed and cooled to room temperature to obtain the aluminum electrolytic capacitor electrolyte.

9. The method according to claim 8, characterized in that The first temperature is 110°C to 150°C; Optionally, the second temperature is 70°C to 100°C; Optionally, the third temperature is 100° C. to 150° C., and the preset time is 1 h to 3 h; Optionally, the fourth temperature is 40°C to 60°C.

10. An aluminum electrolytic capacitor, characterized in that: include: The aluminum electrolytic capacitor electrolyte according to any one of claims 1 to 6 or the aluminum electrolytic capacitor electrolyte prepared by the method according to claims 7 to 9.

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