Flash fire improver for electrolyte of boron-free aluminum electrolytic capacitor and preparation method of flash fire improver

Abstract

The invention relates to the technical field of flash fire lifting agents, and discloses a flash fire lifting agent of an electrolyte of a boron-free aluminum electrolytic capacitor and a preparation method of the flash fire lifting agent, and the flash fire lifting agent comprises the following components in percentage by mass: 10-30% of organic ammonium carboxylate; 5%-15% of a nitro compound; 3%-10% of a phosphate ester compound; 2%-8% of a polyethylene glycol derivative; 0.5%-3% of organic siloxane; and the balance of deionized water. Through the synergistic effect of the organic ammonium carboxylate, the nitro compound, the phosphate ester substance and the organosiloxane in a specific proportion, the sparking voltage of the electrolyte is remarkably improved, and the negative effects of boron elements on the environment and the performance of a capacitor are avoided; a nitro compound is used as an electron acceptor to inhibit hydrogen precipitation, and cooperates with phosphate to fill oxide film micropores and block current concentration; the organic siloxane forms a hydrophobic barrier on an electrode interface, electrolyte decomposition is delayed, the organic carboxylic acid ammonium salt accurately controls the free acid concentration, and the conductivity rise caused by hydrogen ion migration is avoided.

Description

Technical Field

[0001] This invention relates to the field of flashover enhancer technology, specifically to a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors and its preparation method. Background Technology

[0002] With advancements in technology, the development of aluminum electrolytic capacitors has made significant progress. An aluminum electrolytic capacitor is made by inserting a bent aluminum strip as the positive electrode, with an aluminum cylinder as the negative electrode and filled with liquid electrolyte. It also requires DC voltage treatment to form an oxide film on the positive electrode as the dielectric. Its characteristics include large capacitance, but also high leakage current, poor stability, and positive and negative polarity, making it suitable for power supply filtering or low-frequency circuits.

[0003] Traditional electrolytes typically add boric acid or borate as flash voltage boosters. Borides are prone to crystallization and precipitation at high temperatures, leading to increased capacitor conductivity and reduced lifespan. Furthermore, existing boron-free formulations struggle to balance high flash voltage and low conductivity, exhibiting poor high-temperature stability. Therefore, this paper proposes a flash voltage booster for the electrolyte of boron-free aluminum electrolytic capacitors and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a flash voltage booster for the electrolyte of boron-free aluminum electrolytic capacitors and its preparation method, in order to solve the problems mentioned in the background art, which are that traditional electrolytes usually add boric acid or borate as flash voltage boosters, and that borides are prone to crystallization and precipitation at high temperatures, leading to increased capacitor conductivity and reduced lifespan. Furthermore, existing boron-free formulations are difficult to balance high flash voltage and low conductivity, and have poor high-temperature stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor, wherein the flashover enhancer is composed of the following components: organic carboxylic acid ammonium salt, nitro compound, phosphate ester compound, polyethylene glycol derivative, organosiloxane, and deionized water; The flashover enhancer comprises the following components by mass percentage: Organic carboxylic acid ammonium salts: 10%-30%; Nitro compounds: 5%-15%; Phosphate esters: 3%-10%; Polyethylene glycol derivatives: 2%-8%; Organosiloxanes: 0.5%-3%; The remainder is deionized water.

[0006] Preferably, the above-mentioned organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate.

[0007] Preferably, the nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol.

[0008] Preferably, the phosphate ester compound mentioned above is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate.

[0009] Preferably, the polyethylene glycol derivative mentioned above is at least one of polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 600, with a molecular weight range of 200-600.

[0010] Preferably, the organosiloxanes mentioned above are one of amino-modified silicone oils or epoxy-modified silicone oils.

[0011] This invention also provides a method for preparing a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors, comprising the following steps: S1. Heat deionized water to 40-60℃, add organic carboxylic acid ammonium salt, and stir until completely dissolved; S2. Add the nitro compound, phosphate ester compound and polyethylene glycol derivative in sequence, stirring at 200-400 rpm; S3. Cool the system to 25-35℃, slowly add organosiloxane, and disperse it with ultrasound for 10-20 minutes. S4. After filtration, allow to stand for aging for 24-48 hours to obtain a uniform and transparent flashover enhancer.

[0012] Preferably, in step S2, the stirring time is 20-40 minutes.

[0013] Preferably, in S3, the ultrasonic frequency is 20-40kHz.

[0014] Preferably, the amount of the flashover enhancer prepared in S4 added to the electrolyte is 0.5%-5% of the total mass of the electrolyte.

[0015] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects: This invention significantly improves the flash voltage of the electrolyte through the synergistic effect of a specific ratio of organic carboxylic acid ammonium salts, nitro compounds, phosphate esters, and organosiloxanes, avoiding the negative impact of boron on the environment and capacitor performance. At the same time, it avoids the toxic risks of boron to the ecosystem from the source, prevents boron-containing waste from polluting the environment, and the organic carboxylic acid ammonium salts and polyethylene glycol derivatives are biodegradable, reducing the difficulty of waste disposal.

[0016] This invention uses nitro compounds as electron acceptors to inhibit hydrogen evolution, and synergistically uses phosphate esters to fill the micropores of the oxide film, thus blocking current concentration. Organosiloxanes form a hydrophobic barrier at the electrode interface to delay electrolyte decomposition, and organic carboxylic acid ammonium salts precisely control the free acid concentration to avoid conductivity increase caused by hydrogen ion migration.

[0017] The preparation process of this invention is simple and suitable for the industrial production of high-voltage, long-life aluminum electrolytic capacitors. It has excellent high temperature resistance and stability. The high thermal decomposition temperature of the phosphate ester compounds prevents high-temperature carbonization. Ultrasonic dispersion ensures stable dispersion of nano-sized siloxanes, eliminating performance fluctuations caused by local aggregation. Static aging allows the colloidal system to reach thermodynamic equilibrium, and no precipitation occurs during long-term storage. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the preparation method of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0021] Please see Figure 1 The present invention provides a technical solution: a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor, the flashover enhancer being composed of the following components: organic carboxylic acid ammonium salt, nitro compound, phosphate ester compound, polyethylene glycol derivative, organosiloxane and deionized water; The flashover enhancer comprises the following components by weight percentage: ammonium organic carboxylate salt: 20%; nitro compounds: 8%; phosphate ester compounds: 5%; polyethylene glycol derivatives: 3%; organosiloxanes: 1%; the balance being deionized water.

[0022] The organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate; the nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol; the phosphate ester compound is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate; the polyethylene glycol derivative is at least one of polyethylene glycol 200, polyethylene glycol 400, or polyethylene glycol 600, with a molecular weight range of 200-600; and the organosiloxane is one of amino-modified silicone oil or epoxy-modified silicone oil.

[0023] This invention also provides a method for preparing a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors, comprising the following steps: S1. Heat the deionized water to 40°C. Heating helps with subsequent dissolution and reduces the risk of volatilization. Add the organic carboxylic acid ammonium salt and stir until completely dissolved. It is essential to ensure that the organic carboxylic acid ammonium salt is completely dissolved. The solution in which the organic carboxylic acid ammonium salt is completely dissolved should be homogeneous, transparent, and free of obvious particles or turbidity. The stirring time can be extended appropriately, and the solution should be observed and confirmed when there is no reflection on the liquid surface. S2. Add the nitro compound, phosphate ester compound and polyethylene glycol derivative in sequence, one by one. Add the first one until the first one is basically evenly dispersed. This helps to reduce the risk of competitive adsorption or reaction between components and promotes the formation of a more stable system. The stirring speed is 300 rpm and the stirring time is 30 minutes. S3. Cool the system to 25°C and slowly add the organosiloxane to prevent rapid or localized high-concentration addition from causing flocculation, agglomeration, or the formation of coarse emulsion particles. Disperse the organosiloxane with ultrasound for 15 minutes at a frequency of 20-40kHz to fully disperse it into the finest possible droplets. Disperse and emulsify the organosiloxane evenly and stably in the base mixture formed earlier. The dispersed emulsion should be free of obvious floating oil, oil rings, or sediment particles. S4. After filtration, allow the mixture to stand for 36 hours to age. Filtration removes trace solid impurities, large particles or agglomerates that may be introduced into the mixture and equipment, ensuring the uniformity and purity of the final product. The filter material should be a solvent-resistant and inert material, such as nylon, polypropylene, or stainless steel mesh. Transfer the filtered clear liquid to a clean, dry, and sealable container, ensuring that the container is inert and well-sealed. Aging ensures batch stability of the product. Finally, a uniform and transparent flash fire enhancer is obtained. The amount of flash fire enhancer added to the electrolyte is 0.5%-5% of the total mass of the electrolyte. Example

[0024] Unlike Example 1, a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor is composed of the following components: organic carboxylic acid ammonium salt, nitro compound, phosphate ester compound, polyethylene glycol derivative, organosiloxane, and deionized water. The flashover enhancer comprises the following components by weight percentage: ammonium organic carboxylate salt: 20%; nitro compounds: 8%; phosphate ester compounds: 5%; polyethylene glycol derivatives: 3%; organosiloxanes: 1%; the balance being deionized water.

[0025] The organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate; the nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol; the phosphate ester compound is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate; the polyethylene glycol derivative is at least one of polyethylene glycol 200, polyethylene glycol 400, or polyethylene glycol 600, with a molecular weight range of 200-600; and the organosiloxane is one of amino-modified silicone oil or epoxy-modified silicone oil.

[0026] This invention also provides a method for preparing a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors, comprising the following steps: S1. Heat deionized water to 40°C, add organic carboxylic acid ammonium salt, and stir until completely dissolved; S2. Add nitro compounds, phosphate ester compounds and polyethylene glycol derivatives in sequence, stirring at 300 rpm for 30 minutes. S3. Cool the system to 25-35℃, slowly add organosiloxane, and disperse it with ultrasound for 15 minutes at a frequency of 20-40kHz. S4. After filtration, let stand for 36 hours to obtain a uniform and transparent flashover enhancer. The amount of flashover enhancer added to the electrolyte is 0.5%-5% of the total mass of the electrolyte. Example

[0027] Unlike Examples 1 and 2, this is a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor, which is composed of the following components: organic carboxylic acid ammonium salt, nitro compound, phosphate ester compound, polyethylene glycol derivative, organosiloxane, and deionized water. The flashover enhancer comprises the following components by weight percentage: ammonium organic carboxylate salt: 25%; nitro compounds: 8%; phosphate ester compounds: 8%; polyethylene glycol derivatives: 6%; organosiloxanes: 2%; the balance being deionized water.

[0028] The organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate; the nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol; the phosphate ester compound is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate; the polyethylene glycol derivative is at least one of polyethylene glycol 200, polyethylene glycol 400, or polyethylene glycol 600, with a molecular weight range of 200-600; and the organosiloxane is one of amino-modified silicone oil or epoxy-modified silicone oil.

[0029] This invention also provides a method for preparing a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors, comprising the following steps: S1. Heat deionized water to 55°C, add organic carboxylic acid ammonium salt, and stir until completely dissolved; S2. Add nitro compounds, phosphate ester compounds and polyethylene glycol derivatives in sequence, stirring at 300 rpm for 35 minutes. S3. Cool the system to 30°C, slowly add organosiloxane, and disperse it with ultrasound for 20 minutes at a frequency of 20-40 kHz. S4. After filtration, allow to stand and age for 48 hours to obtain a uniform and transparent flashover enhancer. The amount of flashover enhancer added to the electrolyte is 0.5%-5% of the total mass of the electrolyte. Example

[0030] Unlike Examples 1, 2 and 3, this is a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor, which is composed of the following components: organic carboxylic acid ammonium salt, nitro compound, phosphate ester compound, polyethylene glycol derivative, organosiloxane and deionized water; The flashover enhancer comprises the following components by weight percentage: ammonium organic carboxylate salt: 30%; nitro compounds: 11%; phosphate ester compounds: 8%; polyethylene glycol derivatives: 5%; organosiloxanes: 1.5%; the balance being deionized water.

[0031] The organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate; the nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol; the phosphate ester compound is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate; the polyethylene glycol derivative is at least one of polyethylene glycol 200, polyethylene glycol 400, or polyethylene glycol 600, with a molecular weight range of 200-600; and the organosiloxane is one of amino-modified silicone oil or epoxy-modified silicone oil.

[0032] This invention also provides a method for preparing a flashover enhancer for the electrolyte of boron-free aluminum electrolytic capacitors, comprising the following steps: S1. Heat deionized water to 60°C, add organic carboxylic acid ammonium salt, and stir until completely dissolved; S2. Add nitro compounds, phosphate ester compounds and polyethylene glycol derivatives in sequence, stirring at 300 rpm for 40 minutes. S3. Cool the system to 35°C, slowly add organosiloxane, and disperse it with ultrasound for 20 minutes at a frequency of 20-40 kHz. S4. After filtration, let stand for 24 hours to obtain a uniform and transparent flashover enhancer. The amount of flashover enhancer added to the electrolyte is 0.5%-5% of the total mass of the electrolyte.

[0033] In summary, this invention significantly improves the flash voltage of the electrolyte through the synergistic effect of specific proportions of organic carboxylic acid ammonium salts, nitro compounds, phosphate esters, and organosiloxanes, avoiding the negative environmental and capacitor performance effects of boron. It also prevents the toxic risks of boron to the ecosystem from the source, preventing boron-containing waste from polluting the environment. Furthermore, the organic carboxylic acid ammonium salts and polyethylene glycol derivatives are biodegradable, reducing the difficulty of waste disposal. Nitro compounds act as electron acceptors to inhibit hydrogen evolution, while phosphate esters fill the micropores of the oxide film, blocking current concentration. Organosiloxanes form a hydrophobic barrier at the electrode interface, delaying electrolyte decomposition. Organic carboxylic acid ammonium salts precisely control the free acid concentration, preventing conductivity increases due to hydrogen ion migration. The preparation process of this invention is simple and suitable for the industrial production of high-voltage, long-life aluminum electrolytic capacitors. It exhibits excellent high-temperature resistance and stability. The high thermal decomposition temperature of the phosphate esters prevents high-temperature carbonization. Ultrasonic dispersion ensures stable dispersion of nano-sized siloxanes, eliminating performance fluctuations caused by local aggregation. Static aging allows the colloidal system to reach thermodynamic equilibrium, preventing precipitation during long-term storage.

[0034] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor, characterized in that, The flashover enhancer is composed of the following components: organic carboxylic acid ammonium salt, nitro compounds, phosphate ester compounds, polyethylene glycol derivatives, organosiloxanes, and deionized water; The flashover enhancer comprises the following components by mass percentage: Organic carboxylic acid ammonium salts: 10%-30%; Nitro compounds: 5%-15%; Phosphate esters: 3%-10%; Polyethylene glycol derivatives: 2%-8%; Organosiloxanes: 0.5%-3%; The remainder is deionized water.

2. The flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The organic carboxylic acid ammonium salt is selected from at least one of ammonium oxalate, ammonium citrate, or ammonium malate.

3. The flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The nitro compound is at least one of nitrobenzoic acid, nitrosalicylic acid, or p-nitrophenol.

4. The flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The phosphate ester compound is at least one of trimethyl phosphate, triethyl phosphate, or tributyl phosphate.

5. The flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The polyethylene glycol derivative is at least one of polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 600, with a molecular weight range of 200-600.

6. The flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The organosiloxane is one of amino-modified silicone oil or epoxy-modified silicone oil.

7. A method for preparing an electrolyte flashover enhancer for a boron-free aluminum electrolytic capacitor according to any one of claims 1-6, characterized in that: Includes the following steps: S1. Heat deionized water to 40-60℃, add organic carboxylic acid ammonium salt, and stir until completely dissolved; S2. Add the nitro compound, phosphate ester compound and polyethylene glycol derivative in sequence, stirring at 200-400 rpm; S3. Cool the system to 25-35℃, slowly add organosiloxane, and disperse it with ultrasound for 10-20 minutes. S4. After filtration, allow to stand for aging for 24-48 hours to obtain a uniform and transparent flashover enhancer.

8. The method for preparing a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 7, characterized in that: In S2, the stirring time is 20-40 minutes.

9. The method for preparing a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 7, characterized in that: In S3, the ultrasonic frequency is 20-40kHz.

10. The method for preparing a flashover enhancer for the electrolyte of a boron-free aluminum electrolytic capacitor according to claim 1, characterized in that: The amount of the flashover enhancer prepared in S4 added to the electrolyte is 0.5%-5% of the total mass of the electrolyte.

Images