A super low temperature large bolt aluminum electrolytic capacitor and its manufacturing method

Abstract

The present invention belongs to the technical field of capacitor manufacturing, and specifically relates to an ultra-low temperature large bolt aluminum electrolytic capacitor and a manufacturing method thereof. The manufacturing method of the ultra-low temperature large bolt aluminum electrolytic capacitor provided by the present invention comprises the following steps: inserting electrolytic paper between the anode foil and the cathode foil and winding it into a core package; heating and drying the core package, and then placing it in an electrolyte for impregnation treatment, and then post-processing to obtain the ultra-low temperature large bolt aluminum electrolytic capacitor; the electrolyte comprises the following components and their mass fractions: 20-30 parts of solute, 72-82 parts of main solvent, 10-20 parts of auxiliary solvent, 5-10 parts of flash voltage enhancer, 2-5 parts of hydrogen absorber, and 0.1-0.5 parts of waterproof mixture; the auxiliary solvent comprises diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil. The present invention can significantly reduce the capacity change rate, loss, and ESR value of the product at ultra-low temperature, and the ultra-low temperature large bolt aluminum electrolytic capacitor manufactured by the method of the present invention can meet the application environment of -40℃-105℃.

Description

Technical Field

[0001] The invention belongs to the technical field of capacitor manufacturing, and in particular relates to an ultra-low temperature large bolt aluminum electrolytic capacitor and a manufacturing method thereof. Background Art

[0002] As industrial servo robots replace humans in large numbers to perform heavy manual labor, large bolt aluminum electrolytic capacitors used as supporting equipment have also ushered in new application scenarios, which extend to the requirements for ultra-low temperatures (-40℃~105℃). However, the operating temperature of traditional large bolt aluminum electrolytic capacitors is mostly concentrated in (-25℃~105℃ or -25℃~85℃). For example, Chinese patent application CN1707710A discloses an aluminum electrolytic capacitor, which is made of anode aluminum foil, electrolytic paper, cathode aluminum foil, and electrolytic paper overlapped and wound into a cylindrical core, impregnated with electrolyte and sealed in an aluminum shell. The electrolyte is composed of the following components in weight ratio: main electrolyte 10%-30%; solvent 65%-89.95%; additive 0.05%-5%; the main electrolyte is an ammonium salt compound, and the water content relative to the solvent is 15%-95%; the solvent is an alcohol or ether organic solvent; the additive is a waterproof mixture. The electrolytic paper is made by adsorbing the electrolyte by normal pressure or vacuum impregnation method, and the density is ≤0.55g / cm 2 Manila hemp paper, the aluminum shell port is sealed with a rubber plug made of EPDM or butyl rubber or a mixture of EPDM and butyl rubber. Chinese patent application CN108648913A discloses a solid aluminum electrolytic capacitor, which is formed by winding a positive and negative electrode foil and an electrolytic paper into a core package, and the positive and negative electrode foils are riveted with leads, and the leads on the core package pass through the rubber plug holes and are assembled with the aluminum shell, wherein a conductive polymer is grown in the core package, and a polyimide material impregnation protective layer is formed at the aluminum foil cut on the upper and lower surfaces of the core package, and the polyimide material impregnation protective layer is formed by dipping the upper and lower surfaces of the wound core package in a soluble polyamic acid solution and then heating to 220-320°C for dehydration.

[0003] Large bolt aluminum electrolytic capacitors in the prior art mostly use liquid electrolyte as electrolyte. As the temperature drops, large bolt aluminum electrolytic capacitors will experience excessive capacitance decay, increased loss, and increased ESR. These changes in electrical properties will cause irreversible abnormalities in the circuit - failure to start, power reduction, etc. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an ultra-low temperature large bolt aluminum electrolytic capacitor and a manufacturing method thereof. The present invention can significantly reduce the capacity change rate, loss, and ESR value of the product at ultra-low temperature. The ultra-low temperature large bolt aluminum electrolytic capacitor manufactured by the method of the present invention can meet the application environment of -40℃-105℃.

[0005] The technical solution of the present invention is:

[0006] A method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor comprises the following steps:

[0007] Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core package; the core package is heated and dried, then placed in an electrolyte for impregnation treatment, and then post-treated to obtain the ultra-low temperature large bolt aluminum electrolytic capacitor; the electrolyte includes the following components and their mass fractions: 20-30 parts of solute, 72-82 parts of main solvent, 10-20 parts of auxiliary solvent, 5-10 parts of flash voltage enhancer, 2-5 parts of hydrogen absorber, and 0.1-0.5 parts of waterproof mixture; the auxiliary solvent includes diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil.

[0008] Furthermore, the electrolytic paper is one of the electrolytic papers WT-192-20, WT190-30, GT280-30, GT280-35 produced by Zhejiang Kane New Materials Co., Ltd. or the electrolytic papers LDH85-30, LDH85-50, SXDH78-30, SXDH70-50 produced by Japan Kodo Paper Industry Co., Ltd.

[0009] Furthermore, the impregnation treatment is carried out in an impregnation device, which is divided into two parts: an impregnation tank and an electrolyte storage tank. The core package after heating and drying is placed in the impregnation tank (temporarily without electrolyte). The first step is to evacuate the impregnation tank (so that the electrolyte can enter the micropores of the anode foil). The second step is to press the electrolyte from the electrolyte storage tank into the impregnation tank. The third step is to evacuate the impregnation tank with the electrolyte pressed in, so that the electrolyte can enter the core package. The fourth step is to perform a pressurization treatment to facilitate the impregnation of the electrolyte. The fifth step is to release the pressure and restore the normal pressure. The above 5 steps are a cycle, which can be repeated 2-3 times according to the size of the core package.

[0010] Furthermore, the post-processing includes an assembly process, an aging process, a testing process, and a casing process.

[0011] Furthermore, the mass ratio of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in the auxiliary solvent is 7-10:3-5:3-5:1-2.

[0012] Furthermore, the soluble silicone oil is Silquest A-187 coupling agent.

[0013] Furthermore, the solute is composed of 1,6-dodecanedioic acid ammonium, long-chain branched organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 7-10:7-10:1-3.

[0014] The conventional electrolyte for bolt aluminum electrolytic capacitors uses conventional organic carboxylic acid ammonium salts such as ammonium sebacate and ammonium hydrogen azelate, which have problems such as easy precipitation at low temperatures. The solute composed of 1,6-dodecanedioic acid ammonium, long-chain organic carboxylic acid ammonium salt and organic amine substance in a certain mass ratio can effectively improve the ultra-low temperature characteristics of the electrolyte, solve the problems of electrolyte precipitation and stratification at ultra-low temperatures in conventional bolt aluminum electrolytic capacitor electrolytes, and further reduce the capacitance decay and loss of capacitors at low temperatures.

[0015] Furthermore, the long-chain branched organic carboxylic acid ammonium salt is OSK-10 long-chain branched organic carboxylic acid ammonium salt or OSK-12 long-chain branched organic carboxylic acid ammonium salt produced by Okamura Oil Manufacturing Co., Ltd. of Japan.

[0016] Furthermore, the organic amine substance is an alkanolamide type nonionic surfactant, and its chemical structure and main components are:

[0017]

[0018] Furthermore, the organic amine substance is an alkanolamide type nonionic surfactant produced by Sanyo Chemical Industries, Ltd. of Japan, and the product name is PROFAN 128EXTRA.

[0019] Furthermore, the flash voltage enhancer is two of Japanese Kuraray polyvinyl alcohol PVA-117, Japanese JVP polyvinyl alcohol JP-05 and JR-05.

[0020] Furthermore, the main solvent is ethylene glycol; the hydrogen absorber is selected from at least one of p-nitrobenzoic acid, o-nitroanisole, and o-nitrobenzyl alcohol; and the waterproof mixture is one or two of ammonium dihydrogen phosphate and ammonium hypophosphite.

[0021] Another object of the present invention is to provide an ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the above-mentioned manufacturing method.

[0022] Solvent is the basis of electrolyte and the key factor that determines the working temperature of capacitor. For electrolyte, the choice of solvent is very important. The solvent composed of main solvent and auxiliary solvent of specific composition in the present invention has high stability and excellent temperature characteristics, and can reduce the capacity decay and loss of products at low temperature. Using suitable polyvinyl alcohol in the present invention and adding a certain amount of soluble silicone oil to the auxiliary solvent can not only improve the flash voltage, but also reduce the contact angle between electrolyte and anode foil under low temperature conditions, and reduce the capacity decay rate of products. It solves the technical problem that the capacitors in the prior art increase the contact angle due to low temperature, thereby causing the capacity decay of capacitors to increase at low temperature, and the loss also increases, which in turn causes the capacitors to fail to work normally and power reduction.

[0023] As we all know, aluminum electrolytic capacitors with different usage occasions and different performance requirements need to use different electrolytes, and electrolytes are the core technology of capacitor manufacturers. Through a large number of creative experiments, the present invention has developed a method that can significantly reduce the capacity change rate, loss, and ESR value of products at ultra-low temperatures. The ultra-low temperature large bolt aluminum electrolytic capacitor manufactured by the method of the present invention can meet the application environment of -40℃—105℃.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention can significantly reduce the capacity change rate, loss and ESR value of the product at ultra-low temperature. The ultra-low temperature large bolt aluminum electrolytic capacitor manufactured by the method of the present invention can meet the application environment of -40°C-105°C. Its capacity attenuation rate is low under the environment of -40°C, which expands the application scope of the product on the market. DETAILED DESCRIPTION

[0026] The present invention is further illustrated below through the description of specific implementation modes, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0027] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0028] Embodiment 1: A method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor

[0029] The method for manufacturing the ultra-low temperature large bolt aluminum electrolytic capacitor comprises the following steps:

[0030] S1: Electrolytic paper is inserted between the anode foil and cathode foil of aluminum oxide having valve metal properties and forming an insulating medium by electrochemical means, and the foil is wound into a core package; the electrolytic paper is the electrolytic paper WT-192-20 produced by Zhejiang Kaien New Materials Co., Ltd.;

[0031] S2 heats and dries the core package at a temperature of 80°C for 1 hour;

[0032] S3: placing the core package after the heating and drying treatment in an impregnation cylinder, evacuating the impregnation cylinder, pressing the electrolyte from the electrolyte storage cylinder into the electrolyte impregnation cylinder, evacuating the impregnation cylinder with the electrolyte pressed into it, performing a pressurization treatment, releasing the pressure and restoring the pressure to normal, the above 5 steps constitute a cycle, and repeating 3 times;

[0033] S4 takes the core package after the impregnation treatment in step S3, and connects the core package to the cover terminal by using a laser welding machine; after the connection, it is placed in an aluminum shell, and the product is assembled by an assembly machine to obtain a bare product;

[0034] S5: After cleaning and drying the bare products assembled in step S4, the products are placed in an aging machine to perform aging treatment on each product;

[0035] S6: The product after aging treatment in step S5 is subjected to a testing process and a casing process to obtain an ultra-low temperature large bolt aluminum electrolytic capacitor.

[0036] The electrolyte includes the following components and their mass fractions: 20 parts of solute, 72 parts of main solvent, 10 parts of auxiliary solvent, 5 parts of flash voltage enhancer, 2 parts of hydrogen absorber, and 0.1 parts of waterproof mixture; the solute is composed of 1,6-dodecanedionammonium, long-chain organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 7:10:3; the long-chain organic carboxylic acid ammonium salt is OSK-12 long-chain organic carboxylic acid ammonium salt of Okamura Oil Manufacturing Co., Ltd. of Japan; the organic amine substance is an alkanolamide type nonionic surfactant of Sanyo Chemical Industries, Ltd. of Japan, product name: PROFAN 128EXTRA; the main solvent is ethylene glycol; the auxiliary solvent is composed of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in a mass ratio of 7:5:5:2; the soluble silicone oil is Silquest A-187 coupling agent; the flash voltage enhancer is composed of Japanese Kuraray polyvinyl alcohol PVA-117 and Japanese JVP polyvinyl alcohol JP-05 in a mass ratio of 2:5; the hydrogen absorber is p-nitrobenzoic acid; and the waterproof mixture is ammonium dihydrogen phosphate.

[0037] The preparation method of the electrolyte for the ultra-low temperature large bolt aluminum electrolytic capacitor is as follows:

[0038] (1) taking the main solvent, the flash voltage enhancer and the auxiliary solvent in the formula amount in a heated stirring kettle, stirring them fully, heating to 125° C., keeping the temperature at 125° C. for 2 hours, and cooling to 105° C. to obtain a mixed solvent A;

[0039] (2) adding a formulated amount of solute to the heated stirred tank containing the mixed solvent A in step (1), stirring thoroughly, heating to 115° C., and keeping the temperature at 115° C. for 2 hours, and cooling to 90° C. to obtain a mixed solvent B;

[0040] (3) Add the formulated amount of waterproofing agent and hydrogen absorbent to the heated stirring kettle containing mixed solvent B in step (2), heat to 125°C, stir for 1 hour, cool to 85°C, stir thoroughly and test for moisture, then cool to room temperature for use.

[0041] Embodiment 2: A method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor

[0042] The method for manufacturing the ultra-low temperature large bolt aluminum electrolytic capacitor comprises the following steps:

[0043] S1: Electrolytic paper is inserted between the anode foil and cathode foil of aluminum oxide having valve metal properties and forming an insulating medium by electrochemical means, and the foil is wound into a core package; the electrolytic paper is electrolytic paper LDH85-30 produced by Japan Kodo Paper Industry Co., Ltd.;

[0044] S2 heats and dries the core package at a temperature of 90°C for 2 hours;

[0045] S3: placing the core package after the heating and drying treatment in an impregnation cylinder, evacuating the impregnation cylinder, pressing the electrolyte from the electrolyte storage cylinder into the electrolyte impregnation cylinder, evacuating the impregnation cylinder with the electrolyte pressed into it, performing a pressurization treatment, releasing the pressure and restoring the pressure to normal, the above 5 steps constitute a cycle, and repeating 3 times;

[0046] S4 takes the core package after the impregnation treatment in step S3, and connects the core package to the cover terminal by using a laser welding machine; after the connection, it is placed in an aluminum shell, and the product is assembled by an assembly machine to obtain a bare product;

[0047] S5: After cleaning and drying the bare products assembled in step S4, the products are placed in an aging machine to perform aging treatment on each product;

[0048] S6: The product after aging treatment in step S5 is subjected to a testing process and a casing process to obtain an ultra-low temperature large bolt aluminum electrolytic capacitor.

[0049] The electrolyte includes the following components and their mass fractions: 30 parts of solute, 82 parts of main solvent, 20 parts of auxiliary solvent, 10 parts of flash voltage enhancer, 5 parts of hydrogen absorber, and 0.5 parts of waterproof mixture; the solute is composed of 1,6-dodecanedioic acid ammonium, long-chain organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 10:7:1; the long-chain organic carboxylic acid ammonium salt is OSK-10 long-chain organic carboxylic acid ammonium salt of Okamura Oil Manufacturing Co., Ltd. of Japan; the organic amine substance is an alkanolamide type nonionic surfactant of Sanyo Chemical Industries, Ltd. of Japan, product name: PROFAN 128EXTRA; the main solvent is ethylene glycol; the auxiliary solvent is composed of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in a mass ratio of 10:3:3:1; the soluble silicone oil is Silquest A-187 coupling agent; the flash voltage enhancer is composed of Japanese Kuraray polyvinyl alcohol PVA-117 and Japanese JVP polyvinyl alcohol JR-05 in a mass ratio of 1:3; the hydrogen absorber is o-nitrobenzyl alcohol; and the waterproof mixture is ammonium hypophosphite.

[0050] The preparation method of the electrolyte for the ultra-low temperature large bolt aluminum electrolytic capacitor is similar to that of Example 1. Example 3: A method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor

[0051] The method for manufacturing the ultra-low temperature large bolt aluminum electrolytic capacitor comprises the following steps:

[0052] S1: Electrolytic paper is inserted between the anode foil and cathode foil of aluminum oxide which has valve metal characteristics and forms an insulating medium by electrochemical means, and the foil is wound into a core package; the electrolytic paper is electrolytic paper GT280-30 produced by Zhejiang Kaien New Materials Co., Ltd.;

[0053] S2 heats and dries the core package at a temperature of 85°C for 1.5 hours;

[0054] S3: placing the core package after the heating and drying treatment in an impregnation cylinder, evacuating the impregnation cylinder, pressing the electrolyte from the electrolyte storage cylinder into the electrolyte impregnation cylinder, evacuating the impregnation cylinder with the electrolyte pressed into it, pressurizing it, releasing the pressure and restoring it to normal pressure. The above 5 steps constitute a cycle, which is repeated 2-3 times;

[0055] S4 takes the core package after the impregnation treatment in step S3, and connects the core package to the cover terminal by using a laser welding machine; after the connection, it is placed in an aluminum shell, and the product is assembled by an assembly machine to obtain a bare product;

[0056] S5: After cleaning and drying the bare products assembled in step S4, the products are placed in an aging machine to perform aging treatment on each product;

[0057] S6: The product after aging treatment in step S5 is subjected to a testing process and a casing process to obtain an ultra-low temperature large bolt aluminum electrolytic capacitor.

[0058] The electrolyte includes the following components and their mass fractions: 24 parts of solute, 75 parts of main solvent, 12 parts of auxiliary solvent, 7 parts of flash voltage enhancer, 3 parts of hydrogen absorber, and 0.3 parts of waterproof mixture; the solute is composed of 1,6-dodecanedionammonium, long-chain organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 8:8:3; the long-chain organic carboxylic acid ammonium salt is OSK-12 long-chain organic carboxylic acid ammonium salt of Okamura Oil Manufacturing Co., Ltd. of Japan; the organic amine substance is an alkanolamide type nonionic surfactant of Sanyo Chemical Industries, Ltd. of Japan, product name: PROFAN 128EXTRA; the main solvent is ethylene glycol; the auxiliary solvent is composed of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in a mass ratio of 9:4:4:2; the soluble silicone oil is Silquest A-187 coupling agent; the flash voltage enhancer is composed of Japanese Kuraray polyvinyl alcohol PVA-117 and Japanese JVP polyvinyl alcohol JP-05 in a mass ratio of 2:7; the hydrogen absorber is composed of p-nitrobenzoic acid and o-nitrobenzyl alcohol in a mass ratio of 5:2; the waterproof mixture is ammonium hypophosphite.

[0059] The preparation method of the electrolyte for the ultra-low temperature large bolt aluminum electrolytic capacitor is similar to that of Example 1.

[0060] Comparative Example 1: A method for manufacturing a large bolted aluminum electrolytic capacitor

[0061] The manufacturing method of the large bolt aluminum electrolytic capacitor is similar to that of Example 3.

[0062] The difference from Example 3 is that no soluble silicone oil is added to the auxiliary solvent.

[0063] Comparative Example 2: A method for manufacturing a large bolted aluminum electrolytic capacitor

[0064] The manufacturing method of the large bolt aluminum electrolytic capacitor is similar to that of Example 3.

[0065] The difference from Example 3 is that the soluble silicone oil in the auxiliary solvent is replaced by water-soluble silicone oil 204 (Shenzhen Xinzhoubang Technology Co., Ltd.).

[0066] Comparative Example 3: A method for manufacturing a large bolt aluminum electrolytic capacitor

[0067] The manufacturing method of the large bolt aluminum electrolytic capacitor is similar to that of Example 3.

[0068] The difference from Example 3 is that the auxiliary solvent consists of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in a mass ratio of 1:1:1:1.

[0069] Comparative Example 4: A method for manufacturing a large bolted aluminum electrolytic capacitor

[0070] The manufacturing method of the large bolt aluminum electrolytic capacitor is similar to that of Example 3.

[0071] The difference from Example 3 is that the solute is composed of 1,6-dodecanedioic acid ammonium, long-chain branched organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 1:1:1.

[0072] Comparative Example 5: A method for manufacturing a large bolted aluminum electrolytic capacitor

[0073] The manufacturing method of the large bolt aluminum electrolytic capacitor is similar to that of Example 3.

[0074] The difference from Example 3 is that the flash voltage enhancer is Japanese Kuraray polyvinyl alcohol PVA-124.

[0075] Test Example 1: Conventional electrical performance test

[0076] 1. Test materials: Ultra-low temperature large bolt aluminum electrolytic capacitors with specifications of 400V 4700μF and dimensions of 77×143 were manufactured according to the methods of Examples 1, 2 and 3, with 10 in each group and 30 in total.

[0077] 2. Test methods:

[0078] The experiment was carried out at a temperature of 20°C and a frequency of 120Hz. The capacity (CAP) and loss (DF) of the capacitor were tested using an LCR bridge, and the leakage current (LC) was tested using a leakage current meter. The voltage was set to the rated working voltage, and the average value of 10 capacitors was taken as the test result.

[0079] 3. Test results:

[0080] The test results are shown in Table 1. Judgment criteria: Initial value CAP: 4700±20%, DF≤20%, LC≤37600μA. After the test, the electrical performance of the product must meet the standard to determine that the product has passed the test and is qualified.

[0081] Table 1 Conventional electrical performance test results

[0082] index Example 1 Example 2 Example 3 CAP(μF) 4278 4319 4365.8 DF(%) 6.0 5.6 5.2 LC(μA) 982.6 916.2 843.5

[0083] It can be seen from Table 1 that the electrical properties of the ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the method of the present invention meet the standards and the product is qualified.

[0084] Test Example 2: Low Temperature Electrical Performance Test

[0085] 1. Test materials: Aluminum electrolytic capacitors with a specification of 400V 4700μF and a size of 77×143 were prepared according to the methods of Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5, with 10 capacitors in each group, for a total of 60 capacitors.

[0086] 2. Test methods:

[0087] The experiment was conducted at a frequency of 120Hz. The test material was placed in a test machine set at 20℃ for 2 hours, and then its capacity (CAP), loss (DF), and equivalent series resistance (ESR) were tested; the test material was then placed in a test machine set at -40℃ for 2 hours, and then its capacity (CAP), loss (DF), and equivalent series resistance (ESR) were tested. The changes in capacity, loss, and ESR at different temperatures were analyzed. The average value of 10 pieces was taken as the test result.

[0088] 3. Test results:

[0089] The test results are shown in Table 2.

[0090] Table 2 Low temperature electrical performance test results

[0091]

[0092] It can be seen from Table 2 that the capacity change rate, loss and ESR value of the ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the present invention at -40°C are significantly lower than those of Comparative Examples 1-5. It can be seen that the present invention can significantly reduce the capacity change rate, loss and ESR value of the product at ultra-low temperature, and can meet the application environment of -40°C.

[0093] Test Example 3: High Temperature Durability Test

[0094] 1. Test materials: Aluminum electrolytic capacitors with specifications of 400V 4700μF and dimensions of 77×143 were prepared according to the methods of Example 3, Comparative Example 3 and Comparative Example 4, with 10 capacitors in each group, for a total of 30 capacitors.

[0095] 2. Test methods:

[0096] (1) Test the product's capacity (CAP), loss (DF) and leakage current (LC) before the test. (2) Install the product on the test fixture of the ripple power supply, adjust the test voltage (DC voltage + ripple voltage = rated working voltage) and ripple current. Then put the product in a 105°C oven. After a specific time, take it out and test its related electrical performance parameters, and repeat the action of (2). Until the rated working life is completed.

[0097] 3. Test results:

[0098] The test results are shown in Table 3.

[0099] Table 3 High temperature durability test results

[0100]

[0101] It can be seen from Table 3 that the changes in capacity, loss and leakage current of the ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the present invention after 2000 hours are all smaller than those of the aluminum electrolytic capacitors prepared by Comparative Examples 3 and 4, which indicates that the ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the present invention has excellent high temperature stability and long service life.

Claims

1. A method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor, characterized in that: The following steps are involved: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core package; the core package is heated and dried, and then placed in an electrolyte for impregnation treatment, and then post-treated to obtain the ultra-low temperature large bolt aluminum electrolytic capacitor; the electrolyte includes the following components and their mass fractions: 20-30 parts of solute, 72-82 parts of main solvent, 10-20 parts of auxiliary solvent, 5-10 parts of flash voltage enhancer, 2-5 parts of hydrogen absorber, and 0.1-0.5 parts of waterproof mixture; the auxiliary solvent includes diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil; The solute is composed of 1,6-dodecanedioic acid ammonium, long-chain branched organic carboxylic acid ammonium salt and organic amine substance in a mass ratio of 7-10:7-10:1-3; The organic amine substance is an alkanolamide type nonionic surfactant; The main solvent is ethylene glycol; The mass ratio of diethylene glycol, N,N-dimethylformamide, glycerol and soluble silicone oil in the auxiliary solvent is 7-10:3-5:3-5:1-2.

2. The method for manufacturing an ultra-low temperature large bolt aluminum electrolytic capacitor according to claim 1, characterized in that: The hydrogen absorber is selected from at least one of p-nitrobenzoic acid, o-nitroanisole, and o-nitrobenzyl alcohol; and the waterproof mixture is one or two of ammonium dihydrogen phosphate and ammonium hypophosphite.

3. An ultra-low temperature large bolt aluminum electrolytic capacitor prepared by the manufacturing method according to any one of claims 1 to 2.

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