High-temperature-resistant aluminum electrolytic capacitor and preparation process thereof

Abstract

The application relates to the field of aluminum electrolytic capacitors, and discloses a high-temperature-resistant aluminum electrolytic capacitor and a preparation process thereof. The high-temperature-resistant aluminum electrolytic capacitor comprises a shell, a capacitor core and a rubber plug, the capacitor core is accommodated in the shell, the rubber plug is used for sealing the shell, the capacitor core is prepared by immersing a core body in a high-temperature-resistant electrolyte, the core body is formed by winding an anode aluminum foil, a cathode aluminum foil and electrolytic paper, and the electrolytic paper is arranged between the anode aluminum foil and the cathode aluminum foil; the high-temperature-resistant electrolyte is prepared from the following raw materials in percentage by weight: 55-64% of a solvent, 20-30% of a solute, 4-8% of a stabilizer, 3-4.5% of a glycidyl ester substance, 2-4% of a flash voltage enhancer, 1.5-3.5% of a corrosion inhibitor and 0.5-1% of a hydrogen removal agent. The aluminum electrolytic capacitor has good high-temperature resistance, good charge storage and release stability, and good reliability and stability in long-term use in a high-temperature environment.

Description

A high-temperature resistant aluminum electrolytic capacitor and its manufacturing process Technical Field

[0001] This application relates to the field of aluminum electrolytic capacitors, and more specifically, to a high-temperature resistant aluminum electrolytic capacitor and its manufacturing process. Background Technology

[0002] Aluminum electrolytic capacitors are capacitors with positive and negative electrodes. Their basic structure consists of an anode aluminum foil, a cathode aluminum foil, and a layer of electrolyte-impregnated paper sandwiched between them, all wound together and sealed with an aluminum shell and a rubber cap. After the electrodes are immersed in the electrolyte, an extremely thin aluminum oxide film forms on the surface of the positive electrode through electrolysis. This aluminum oxide film has a high dielectric constant and can store electrical charge. Aluminum electrolytic capacitors offer advantages such as large size, high capacitance, and low cost, and are widely used in power supply filtering circuits, switching power supplies, automotive applications, LED lighting, industrial frequency conversion, and new energy applications, providing crucial support for the high performance and long lifespan of electronic equipment.

[0003] Electrolyte plays a crucial role in aluminum electrolytic capacitors. It maintains capacitance, repairs the alumina film, and thus ensures the stability of charge storage and release. Existing electrolytes typically contain solvents such as ethylene glycol and glycerol, with solutes primarily being borates or their derivatives. Additives, such as benzotriazole and trimesic acid, may also be added to enhance performance. The relatively low boiling points of these solvents make the electrolyte prone to volatilization and aging at high temperatures, affecting its stability and conductivity. The limited thermal stability of the solutes leads to decomposition at high temperatures, degrading electrolyte performance and impacting the charge storage and release stability of the aluminum electrolytic capacitor. While additives can improve performance, their effectiveness diminishes at high temperatures, failing to effectively address the performance degradation of electrolytes under these conditions.

[0004] Especially with the advancement of technology and the diversification of application environments, the requirements for aluminum electrolytic capacitors, particularly in new energy drive power supplies, are becoming increasingly stringent. During long-term operation, the temperature of new energy drive power supplies rises continuously. When aluminum electrolytic capacitors operate under prolonged high temperatures, the electrolyte is prone to evaporation and aging, leading to a decline in capacitor performance and potentially causing failure, thus affecting the stability and reliability of the entire circuit. Summary of the Invention

[0005] To address the issue that electrolytes in aluminum electrolytic capacitors are prone to evaporation and aging under long-term high-temperature conditions, leading to reduced stability of the capacitors, this application provides a high-temperature resistant aluminum electrolytic capacitor and its manufacturing process.

[0006] In a first aspect, this application provides a high-temperature resistant aluminum electrolytic capacitor, which adopts the following technical solution:

[0007] A high-temperature resistant aluminum electrolytic capacitor includes a housing, a capacitor core, and a rubber stopper. The capacitor core is housed within the housing, and the rubber stopper seals the housing. The capacitor core is made by impregnating a core body with a high-temperature resistant electrolyte. The core body is formed by winding an anode aluminum foil, a cathode aluminum foil, and electrolytic paper, with the electrolytic paper positioned between the anode and cathode aluminum foils. The high-temperature resistant electrolyte is prepared from the following raw materials in weight percentages: solvent 55-64%, solute 20-30%, stabilizer 4-8%, glycidyl esters 3-4.5%, flashover voltage enhancer 2-4%, corrosion inhibitor 1.5-3.5%, and hydrogen scavenger 0.5-1%.

[0008] By adopting the above technical solution, the high-temperature resistant aluminum electrolytic capacitor has a reasonable structural design. The capacitor core is housed in the shell and sealed with a rubber stopper, which can avoid interference from external factors and improve the overall structural stability and sealing performance. The capacitor core is made of a core body soaked in high-temperature resistant electrolyte, which allows the electrolyte to fully function and ensures effective storage and release of charge.

[0009] In high-temperature resistant electrolytes, the solvent accounts for 55-65%, providing a good dissolution environment for other components and ensuring uniform dispersion; the solute accounts for 20-30%, participating in charge transport and maintaining the conductivity of the electrolyte; the stabilizer accounts for 4-8%, enhancing the thermal stability of the electrolyte, preventing its decomposition at high temperatures, and ensuring stable electrolyte performance; glycidyl esters account for 3-4.5%, improving the chemical stability of the electrolyte and enhancing its resistance to chemical reactions at high temperatures; flash voltage enhancer accounts for 2-4%, increasing the flash voltage of the electrolyte, reducing the risk of breakdown, and improving safety; corrosion inhibitor accounts for 1.5-3.5%, inhibiting the corrosion of metal components and extending the service life of capacitors; and hydrogen scavenger accounts for 0.5-1%, eliminating hydrogen and preventing safety hazards caused by hydrogen accumulation.

[0010] There is a synergistic effect among the stabilizer, glycidyl esters, and flash voltage booster. The stabilizer improves the thermal stability of the electrolyte, allowing the glycidyl esters and flash voltage booster to function better at high temperatures. The enhanced chemical stability of the glycidyl esters helps the stabilizer maintain its stability and also assists the flash voltage booster in increasing the flash voltage. The reduced breakdown risk of the flash voltage booster creates a more stable working environment for the stabilizer and glycidyl esters, further enhancing their effectiveness.

[0011] In summary, the aluminum electrolytic capacitor of this application has good high temperature resistance. When used in a high temperature environment for a long time, the electrolyte can maintain stable performance, and the charge storage and release are stable. It effectively avoids the capacitor performance degradation and failure caused by electrolyte volatilization, aging and performance degradation, and has good reliability and stability.

[0012] Preferably, the solvent is composed of ethylene glycol, γ-caprolactone, ethylene glycol monobutyl ether and diethylene glycol in a weight ratio of (3-4):(1-2):(1.5-2.5):1.

[0013] By adopting the above technical solution, ethylene glycol, γ-caprolactone, ethylene glycol monobutyl ether and diethylene glycol are compounded in a better weight ratio as solvents in the high-temperature resistant electrolyte, which can improve the fluidity and electrolytic stability of the high-temperature resistant electrolyte, effectively reduce the volatility of the high-temperature resistant electrolyte when operating in a high-temperature environment, and make the performance of the high-temperature resistant aluminum electrolytic capacitor more stable.

[0014] Preferably, the solute is a combination of at least two of ammonium hydrogen phosphate, ammonium sebacate, ammonium azelaate, and ammonium adipate.

[0015] By adopting the above technical solution, at least two combinations of ammonium hydrogen phosphate, ammonium sebacate, ammonium azelate, and ammonium adipate are used as solutes in the high-temperature resistant electrolyte. These solutes, together with solvents, stabilizers, glycidyl esters, flash voltage enhancers, corrosion inhibitors, and hydrogen scavengers, constitute the electrolyte system. These solutes provide ions to participate in the electrolytic reaction, forming a stable alumina film on the anode aluminum foil surface, maintaining the conductivity of the electrolyte, and thus ensuring the stability of charge storage and release in the aluminum electrolytic capacitor under high-temperature conditions. This gives the aluminum electrolytic capacitor good high-temperature resistance and good reliability and stability during long-term use in high-temperature environments.

[0016] Preferably, the stabilizer is composed of laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a weight ratio of 1:(0.2-0.4).

[0017] By employing the above technical solution, using laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a superior weight ratio as stabilizers can improve the stability of the electrolyte. Laurylamine dipropylenediamine has good film-forming properties and chemical stability, forming a protective film on the electrode surface to prevent side reactions between the electrode and the electrolyte, reducing electrolyte volatilization and aging at high temperatures. 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate helps improve the overall heat resistance of the electrolyte, preventing the decomposition of the solute and solvent system at high temperatures. The synergistic effect of these two components allows the electrolyte to maintain good stability and conductivity in high-temperature environments, thus improving the reliability and stability of aluminum electrolytic capacitors during long-term use in high-temperature environments.

[0018] Preferably, the glycidyl ester is composed of diglycidyl 1,2-cyclohexanedicarboxylate and diglycidyl tetrahydrophthalate in a weight ratio of (2-4):1.

[0019] By adopting the above technical solution, the glycidyl ester substance composed of diglycidyl 1,2-cyclohexanedicarboxylate and diglycidyl tetrahydrophthalate in a specific weight ratio can work synergistically in the electrolyte system to physically adsorb on the surface of the anodic oxide film, forming a denser and more uniform protective layer. This improves the corrosion resistance and breakdown resistance of the oxide film, resulting in better high-temperature resistance of the aluminum electrolytic capacitor, better reliability and stability in long-term use in high-temperature environments, and extended service life of the capacitor.

[0020] Preferably, the flashover voltage booster is prepared by kneading nano-silica and 2-octenyl succinic anhydride in a weight ratio of 10:(0.4-0.6).

[0021] By adopting the above technical solution, a flashover voltage booster is prepared by kneading nano-silica and 2-octenyl succinic anhydride in a better weight ratio. It can play a good synergistic role with stabilizers and glycidyl esters, which can give aluminum electrolytic capacitors better high temperature resistance, ensure the stability of charge storage and release, prevent discharge flashover on the anodic oxide film surface, and enhance the stability and reliability of capacitors under high voltage.

[0022] Preferably, the corrosion inhibitor is any one or a combination of phosphate ester corrosion inhibitors, benzotriazole corrosion inhibitors, and quaternary ammonium salt corrosion inhibitors.

[0023] By adopting the above technical solution, the corrosion inhibitor can form a protective film on the surface of the anode aluminum foil, effectively inhibiting the corrosion of the anode aluminum foil and preventing the degradation of capacitance performance caused by corrosion. Moreover, they can still maintain good corrosion inhibition effect in high-temperature environments, which can improve the stability and conductivity of the electrolyte, thereby further improving the high-temperature resistance of aluminum electrolytic capacitors and ensuring their reliability and stability when used in long-term high-temperature environments.

[0024] Preferably, the hydrogen scavenger is any one or a combination of p-nitrobenzoic acid, p-nitroanisole, p-nitrobenzyl alcohol, and p-nitrophenol.

[0025] By adopting the above technical solution, hydrogen gas is generated at the cathode during electrolysis. Excessive hydrogen gas can cause the internal pressure of the capacitor to rise, which may even lead to bulging or the opening of the explosion-proof valve in severe cases. The hydrogen scavenging agent mentioned above can react with hydrogen ions to reduce hydrogen evolution, thereby reducing the gas pressure in the high-temperature electrolyte system, avoiding safety problems caused by excessive internal pressure, and extending the service life of the capacitor.

[0026] Secondly, this application provides a manufacturing process for a high-temperature resistant aluminum electrolytic capacitor, employing the following technical solution:

[0027] A manufacturing process for a high-temperature resistant aluminum electrolytic capacitor includes the following steps:

[0028] S1. Stack and wind the anode aluminum foil, electrolytic paper and cathode aluminum foil from the inside out to form a core;

[0029] S2. The core is immersed in a high-temperature resistant electrolyte to obtain the capacitor core;

[0030] S3. Place the capacitor core inside the casing and seal it with a rubber stopper to obtain a high-temperature resistant electrolytic capacitor.

[0031] By adopting the above technical solution, step S1 involves stacking and winding the anode aluminum foil, electrolytic paper, and cathode aluminum foil from the inside out to form a core. The reasonable stacking and winding method ensures that the components are tightly fitted and in a stable position, providing a good physical structural basis for the subsequent storage and release of electrolyte and charge. Step S2 involves immersing the core in a high-temperature resistant electrolyte to obtain a capacitor core, ensuring that the high-temperature resistant electrolyte fully wets the capacitor core. Step S3 involves placing the capacitor core in a housing and sealing it with a rubber stopper to obtain a high-temperature resistant electrolytic capacitor. The sealing measures prevent external impurities from entering and internal electrolyte from leaking, ensuring the overall stability of the capacitor. The steps work together to make the final high-temperature resistant aluminum electrolytic capacitor have good high-temperature resistance and good reliability and stability when used in high-temperature environments for a long time.

[0032] Preferably, the soaking in step S2 is a pressurized soaking, with a pressure of 0.2-0.4 MPa, 3-5 soakings, and each soaking time of 3-5 minutes.

[0033] By adopting the above technical solution, when preparing aluminum electrolytic capacitors, the optimal pressure immersion conditions, such as pressure immersion of 0.2-0.4MPa, 3-5 immersion cycles, and 3-5 minutes of immersion time per cycle, enable the core to more fully absorb the high-temperature resistant electrolyte and penetrate between the anode aluminum foil, cathode aluminum foil, and electrolytic paper, thereby improving the reliability and stability of the aluminum electrolytic capacitor.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. The high-temperature resistant aluminum electrolytic capacitor of this application has a capacitor core made of a core body soaked in a high-temperature resistant electrolyte prepared from raw materials in a specific ratio. The high-temperature resistant electrolyte is prepared from solvent, solute, stabilizer, glycidyl ester, flash voltage booster, corrosion inhibitor and hydrogen scavenger. The aluminum electrolytic capacitor of this application has good high-temperature resistance. When used in a high-temperature environment for a long time, the electrolyte can maintain stable performance, and the charge storage and release are stable. It effectively avoids the degradation of capacitor performance and failure caused by problems such as electrolyte volatilization, aging and performance degradation. It has good reliability and stability.

[0036] 2. The stabilizer is composed of laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, which can solve the problems of easy volatilization, aging and solute decomposition of existing electrolytes under high temperature environment, and improve the stability and conductivity of electrolyte.

[0037] 3. Glycidyl esters, composed of diglycidyl 1,2-cyclohexanedicarboxylate and diglycidyl tetrahydrophthalic acid, help to further improve the performance of aluminum electrolytic capacitors under high-temperature environments.

[0038] 4. The flashover voltage booster is made by kneading nano-silica and 2-octenyl succinic anhydride, which can give aluminum electrolytic capacitors better high temperature resistance, ensure the stability of charge storage and release, prevent discharge flashover on the anodic oxide film surface, and enhance the stability and reliability of capacitors under high voltage.

[0039] 5. The preparation process of this application includes winding an anode aluminum foil, electrolytic paper and a cathode aluminum foil to form a core, then immersing the core under pressure in a high-temperature resistant electrolyte, and finally sealing it. The resulting aluminum electrolytic capacitor has good charge storage and release stability, and excellent reliability and stability when used in a high-temperature environment for a long time. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments.

[0041] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used:

[0042] 1. Laurylamine dipropylenediamine: CAS No. 2372-82-9, purity 99%;

[0043] 2. Nano-silica: Particle size 50-100nm;

[0044] 3. 2-Octenylsuccinic anhydride: CAS No. 26680-54-6, purity 99%.

[0045] Example of preparation of high temperature resistant electrolyte

[0046] Preparation Example 1

[0047] Preparation Example 1 discloses a high-temperature resistant electrolyte, which is prepared by the following steps: 5.5 kg of solvent, 0.8 kg of stabilizer and 0.3 kg of 1,2-cyclohexanedicarboxylic acid diglycidyl ester are heated to 70°C and stirred evenly. 3 kg of solute and 0.2 kg of flash voltage enhancer are added, the temperature is raised to 90°C and stirred evenly, then the temperature is lowered to 60°C, 0.15 kg of corrosion inhibitor and 0.05 kg of p-nitrobenzene ether are added as hydrogen scavenging agent, and the mixture is stirred evenly to obtain the high-temperature resistant electrolyte;

[0048] The solvent consists of ethylene glycol, γ-caprolactone, ethylene glycol monobutyl ether, and diethylene glycol in a ratio of 3:2:1.5:1; the stabilizer consists of dibutyl phosphate and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a ratio of 1:0.2; the solute consists of ammonium sebacate, ammonium oxalate, and ammonium hydrogen phosphate in a weight ratio of 2:1:0.5; the flashover voltage booster is prepared by kneading 50nm nano-silica and polyvinyl alcohol in a weight ratio of 10:0.4 at 100℃; and the corrosion inhibitor consists of polyol phosphate and benzotriazole in a weight ratio of 1:2.

[0049] The polyvinyl alcohol is PVA2399, and the polyol phosphate is Jiyesheng PAPE, with a content of 50%.

[0050] Preparation Examples 2-3

[0051] The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0052] Table 1. Parameters for Preparation Examples 1-3

[0053]

[0054]

[0055] Preparation Example 4

[0056] The difference between Preparation Example 4 and Preparation Example 1 is that the stabilizer consists of laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a weight ratio of 1:0.2, while the rest is the same as Preparation Example 1.

[0057] Preparation Example 5

[0058] The difference between Preparation Example 5 and Preparation Example 1 is that the stabilizer consists of laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a weight ratio of 1:0.4, while the rest is the same as Preparation Example 1.

[0059] Preparation Example 6

[0060] The difference between Preparation Example 6 and Preparation Example 4 is that the glycidyl ester is composed of 1,2-cyclohexanedicarboxylic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester in a weight ratio of 2:1, while the rest is the same as Preparation Example 4.

[0061] Preparation Example 7

[0062] The difference between Preparation Example 7 and Preparation Example 4 is that the glycidyl ester is composed of 1,2-cyclohexanedicarboxylic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester in a weight ratio of 4:1, while the rest is the same as Preparation Example 4.

[0063] Preparation Example 8

[0064] The difference between Preparation Example 8 and Preparation Example 7 is that the flash voltage booster is prepared by kneading 50nm nano-silica and 2-octenyl succinic anhydride in a weight ratio of 10:0.4 at a temperature of 100°C. Otherwise, it is the same as Preparation Example 7.

[0065] Preparation Example 9

[0066] The difference between Preparation Example 9 and Preparation Example 7 is that the flash voltage booster is prepared by kneading 50nm nano-silica and 2-octenyl succinic anhydride in a weight ratio of 10:0.6 at a temperature of 100°C. Otherwise, it is the same as Preparation Example 7.

[0067] Preparation of Comparative Example 1

[0068] The difference between Comparative Example 1 and Preparation Example 1 is that glycidyl esters were replaced with stabilizers in equal amounts; otherwise, they were the same as Preparation Example 1.

[0069] Preparation of Comparative Example 2

[0070] The difference between Comparative Example 2 and Example 1 is that the stabilizer was replaced with an equal amount of flash voltage booster, while the rest was the same as Example 1.

[0071] Example

[0072] Example 1

[0073] Example 1 discloses a high-temperature resistant aluminum electrolytic capacitor, including a shell, a capacitor core, and a rubber stopper. The capacitor core is housed in the shell, and the rubber stopper is used to seal the shell. The rubber stopper is made of butyl fluororubber material, which has good high-temperature resistance and sealing performance. The capacitor core is made by soaking a core body in a high-temperature resistant electrolyte. The core body is formed by winding an anode aluminum foil, a cathode aluminum foil, and electrolytic paper. The electrolytic paper is placed between the anode aluminum foil and the cathode aluminum foil.

[0074] This high-temperature resistant aluminum electrolytic capacitor is manufactured using the following process:

[0075] S1. Stack and wind the anode aluminum foil, electrolytic paper and cathode aluminum foil from the inside out to form a core;

[0076] S2. The core is immersed in a high-temperature resistant electrolyte. The immersion process is a pressurized immersion with a pressure of 0.2 MPa. The immersion is repeated 3 times, and the immersion time is 5 minutes each time, to obtain the capacitor core.

[0077] S3. Place the capacitor core inside the casing and seal it with a rubber stopper to obtain a high-temperature resistant electrolytic capacitor.

[0078] Example 2-3

[0079] The difference between Examples 2-3 and Example 1 is that the source of the high-temperature resistant electrolyte is different and the soaking conditions in step S2 are different, as detailed in Table 2 below.

[0080] Table 2 Parameter table for Examples 1-3

[0081]

[0082] Examples 4-9

[0083] The difference between Examples 4-9 and Example 1 is that the source of the high-temperature resistant electrolyte is different, as detailed in Table 3 below.

[0084] Table 3. Source of high-temperature resistant electrolytes in Examples 4-9

[0085] Examples of High-Temperature Resistant Electrolytes: Example 4 (Preparation Example 4), Example 5 (Preparation Example 5), Example 6 (Preparation Example 6), Example 7 (Preparation Example 7), Example 8 (Preparation Example 8), Example 9 (Preparation Example 9) surface

[0086] Comparative Example

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 9 is that the high-temperature resistant electrolyte was derived from the preparation of Comparative Example 1, while the rest is the same as Example 9.

[0089] Comparative Example 2

[0090] The difference between Comparative Example 2 and Example 9 is that the high-temperature resistant electrolyte was derived from the preparation of Comparative Example 2, while the rest is the same as Example 9.

[0091] Performance testing

[0092] The performance of the high-temperature resistant aluminum electrolytic capacitors prepared in Examples 1-9 and Comparative Examples 1-2 was tested below:

[0093] The high-temperature resistant aluminum electrolytic capacitor is a standard product with a temperature range of -40℃ to +105℃, a diameter of 6.3mm, and a height of 7.7mm.

[0094] After applying a rated voltage of 100V at maximum ripple current for 2000 hours at 105℃, the capacitance, loss tangent (DF), and leakage current were tested respectively. The capacitance was considered qualified if it was within 20% of the initial value, the loss tangent was considered qualified if it did not exceed 200% of the initial value, and the leakage current was considered qualified if it did not exceed 200% of the initial value. The capacitance change rate, loss tangent change rate, and leakage current change rate were used to characterize the capacitance change rate, loss tangent change rate, and leakage current change rate, i.e., capacitance change rate ≤ 20%, loss tangent change rate ≤ 100%, and leakage current change rate ≤ 100%.

[0095] Capacitance change rate = (Capacitance before test - Capacitance after test) / Capacitance before test * 100%;

[0096] Rate of change of loss tangent = (loss tangent after test - loss tangent before test) / loss tangent before test * 100%;

[0097] Leakage current change rate = (leakage current after test - leakage current before test) / leakage current before test * 100%.

[0098] Capacitance and loss tangent testing: The test was conducted using an impedance analyzer at a frequency of 120 Hz under 25°C conditions.

[0099] Leakage current detection: Use a leakage current tester to perform the test at 25℃.

[0100] The following are the performance test data of the high-temperature resistant aluminum electrolytic capacitors of Examples 1-9 and Comparative Examples 1-2, as detailed in Table 4 below.

[0101] Table 4 Performance data of Examples 1-9 and Comparative Examples 1-2

[0102]

[0103] Based on Table 4 above, we can conclude that:

[0104] Compared to Examples 1-3, Examples 4-5 show a lower rate of change in capacitance, a lower rate of change in loss tangent, and a lower rate of change in leakage current. This indicates that using laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate as stabilizers in a better weight ratio can improve the high-temperature electrolytic stability of the high-temperature electrolyte.

[0105] Compared to Example 4, Examples 6-7 further optimized the types and proportions of glycidyl esters, resulting in a lower rate of change in capacitance, a lower rate of change in loss tangent, and a lower rate of change in leakage current in the aluminum electrolytic capacitors.

[0106] Compared with Example 7, Examples 8-9 further optimized the type and proportion of the flashover voltage booster, resulting in a lower rate of change in capacitance, a lower rate of change in loss tangent, and a lower rate of change in leakage current of the aluminum electrolytic capacitors. This indicates that the flashover voltage booster of this application can have a positive effect on the aluminum electrolytic capacitors of this application.

[0107] Compared to Example 9, Comparative Example 1 replaced the glycidyl ester substance, and compared to Example 9, Comparative Example 2 replaced the stabilizer. The resulting aluminum electrolytic capacitors had a capacitance change rate greater than 20%, and the loss tangent and leakage current were both greater than 100%. This indicates that the stabilizer, glycidyl ester substance, and flash voltage booster of this application have a good synergistic effect and can synergistically improve the high-temperature stability of aluminum electrolytic capacitors.

[0108] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high-temperature resistant aluminum electrolytic capacitor, characterized in that, The system includes a housing, a capacitor core, and a rubber stopper. The capacitor core is housed within the housing, and the rubber stopper seals the housing. The capacitor core is made by impregnating a core body with a high-temperature resistant electrolyte. The core body is formed by winding an anode aluminum foil, a cathode aluminum foil, and electrolytic paper, with the electrolytic paper positioned between the anode and cathode aluminum foils. The high-temperature resistant electrolyte is prepared from the following raw materials by weight percentage: solvent 55-64%, solute 20-30%, stabilizer 4-8%, and glycidyl ether. The composition includes 3-4.5% esters, 2-4% flash voltage enhancer, 1.5-3.5% corrosion inhibitor, and 0.5-1% hydrogen scavenger; the stabilizer is composed of laurylamine dipropylenediamine and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in a weight ratio of 1:(0.2-0.4); the glycidyl esters are composed of 1,2-cyclohexanedicarboxylic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester in a weight ratio of (2-4):

1.

2. The high-temperature resistant aluminum electrolytic capacitor according to claim 1, characterized in that, The solvent is composed of ethylene glycol, γ-caprolactone, ethylene glycol monobutyl ether and diethylene glycol in a weight ratio of (3-4):(1-2):(1.5-2.5):

1.

3. The high-temperature resistant aluminum electrolytic capacitor according to claim 1, characterized in that, The solute is a combination of at least two of ammonium hydrogen phosphate, ammonium sebacate, ammonium azelaate, and ammonium adipate.

4. A high-temperature resistant aluminum electrolytic capacitor according to claim 1, characterized in that, The flashover voltage booster is prepared by kneading nano-silica and 2-octenyl succinic anhydride in a weight ratio of 10:(0.4-0.6).

5. A high-temperature resistant aluminum electrolytic capacitor according to claim 1, characterized in that, The corrosion inhibitor is any one or a combination of phosphate ester corrosion inhibitors, benzotriazole corrosion inhibitors, and quaternary ammonium salt corrosion inhibitors.

6. A high-temperature resistant aluminum electrolytic capacitor according to claim 1, characterized in that, The hydrogen scavenger is any one or a combination of p-nitrobenzoic acid, p-nitroanisole, p-nitrobenzyl alcohol, and p-nitrophenol.

7. A manufacturing process for a high-temperature resistant aluminum electrolytic capacitor as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Stack and wind the anode aluminum foil, electrolytic paper, and cathode aluminum foil from the inside out to form a core; S2. Immerse the core in a high-temperature resistant electrolyte to obtain a capacitor core; S3. Place the capacitor core inside the casing and seal it with a rubber stopper to obtain a high-temperature resistant electrolytic capacitor.

8. The manufacturing process of a high-temperature resistant aluminum electrolytic capacitor according to claim 7, characterized in that, The soaking in step S2 is a pressurized soaking, with a pressure of 0.2-0.4 MPa, and the number of soakings is 3-5 times, with each soaking time being 3-5 minutes.

Images