Solid-liquid mixed capacitor low-temperature-resistant electrolyte

Abstract

The invention provides a solid-liquid mixed capacitor low-temperature-resistant electrolyte, the electrolyte contains a solute, a solvent and an additive, the solvent accounts for 30-85% by weight of an ethanol compound and 3-10% by weight of polyalkyl glycol, and the solute is an amino acid compound. The present invention has significant high-temperature stability and reliability, with little change in characteristics from the initial characteristics even when used at high temperatures for a long period of time, which is related to the composition of an electrolyte solution using a conductive polymer hybrid electrolytic capacitor. The lead-free reflow soldering heat resistance, the high-temperature durability of over 125 DEG C and the high voltage resistance characteristic of 63V or more are provided. Not only are the characteristics of low ESR, high ripple current and high capacity maintained, but also the capacitor can be used in a wider rated voltage range of 63-200V.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytes, in particular to a low-temperature resistant electrolyte for aluminum electrolytic capacitors. Background Art

[0002] With the rapid development of modern electronic technology, high requirements are placed on various electronic components. Due to the advantages of high voltage resistance, large capacity, simple production process and low price, aluminum electrolytic capacitors are widely used in various electronic devices. With the development of color TVs, monitors, audio-visual equipment and switching power supplies, the demand for aluminum electrolytic capacitors is increasing and the requirements are getting higher and higher. However, the existing aluminum electrolytic capacitors have low low temperature resistance, which makes the product market defective rate high and cannot meet the normal operation under unstable voltage conditions in the market. Summary of the invention

[0003] The object of the present invention is to provide a solid-liquid mixed capacitor low-temperature resistant electrolyte for aluminum electrolytic capacitors.

[0004] To achieve the above-mentioned purpose, the technical solution provided by the present invention is: a solid-liquid hybrid capacitor low-temperature resistant electrolyte, the electrolyte containing a solute, a solvent and an additive, wherein the amount of ethanol compounds occupied in the solvent is 30-85% by weight, polyalkylene glycol is 3-10%, and the solute is an amino acid compound.

[0005] The solute is a complex compound of alicyclic dicarboxylic acid, organic acid and inorganic acid, or a complex compound of diethylene glycol and triethylene glycol.

[0006] The solvent is composed of isopentanedioic acid and 12-vinyl-8-octadecene dioic acid.

[0007] The acid in the solute is a long-chain dibasic carboxylic acid with a total carbon number of more than 12; the amine is an amine with a boiling point above 150°C.

[0008] The long-chain dibasic carboxylic acid is one or more of dodecane diacid, 2-butyl octanedioic acid, isopentanedioic acid and dicyanic acid.

[0009] The amine is an aromatic amine, a complex amine compound, or an amide having a cyclic skeleton.

[0010] The present invention has remarkable high temperature stability and reliability. Even if used for a long time at high temperature, the characteristic change from the initial characteristic is very small. This is related to the composition of the electrolyte of the conductive polymer hybrid electrolytic capacitor. More specifically, it has the characteristics of lead-free reflow soldering heat resistance, high temperature durability exceeding 125°C, and high withstand voltage characteristics above 63V. It maintains the characteristics of low ESR, high ripple current and high capacity, and can also be used in a wide range of rated voltages from 63V to 200V. DETAILED DESCRIPTION

[0011] The present invention is further described below. A solid-liquid hybrid capacitor low-temperature resistant electrolyte of the present invention comprises a solute, a solvent and an additive, wherein the amount of the ethanol compound in the solvent is 30-85% by weight, the polyalkylene glycol is 3-10%, the solute is an amino acid compound, and the additive is a conductive polymer aqueous solution, wherein the S-type aqueous solution of polyaniline and a self-doping conductive polymer aqueous solution (trade name: 1% SELFTRON) has a viscosity of about 5-10 mPa·s (20°C).

[0012] The solvent uses diethylene glycol and triethylene glycol as the main solvent. In addition, depending on the purpose, γ-butyrolactone alone or a mixed solvent of γ-butyrolactone and tetramethylsilane is used as the second solvent. The amount of ethanol compounds occupied in the entire solvent is at least 30% by weight, preferably in the range of 45%-80% by weight, and the total content of diethylene glycol or / and triethylene glycol and γ-butyrolactone is 80% by weight or more, preferably 85% by weight or more, which is a feature. In addition, it is known that if polyalkylene glycol such as polyethylene glycol or its dielectric is added to the electrolyte, the thermal oxidation degradation of the conductive polymer can be prevented and the repairability of dielectric defects can be improved under severe high-temperature use conditions where the heat caused by ripple current overlaps. In order to suppress the increase in the viscosity of the electrolyte, the average molecular weight of the added polyalkylene glycol is preferably in the range of a relatively low molecular weight of 300 to 1000. If the amount added is too much, the viscosity will increase and the impregnation of the electrolyte will deteriorate, so the maximum 10% and the minimum 3% by weight are better.

[0013] The solute uses amines and amino acids as salt bases of acids such as ammonia and salicylic acid that form a composite compound of alicyclic dicarboxylic acids such as phthalic acid, organic acids, and inorganic acids, and alkylamines such as diethylene glycol and triethylene glycol, which are more alkaline than amino groups, are also recommended. However, by combining the solute containing the above-mentioned acid and salt with a solvent containing diethylene glycol and triethylene glycol as the main components, a high-voltage capacitor with a rated voltage of more than 63V cannot obtain a conductive polymer hybrid aluminum electrolytic capacitor with good initial characteristics and reflow heat resistance, high-temperature durability, and a high temperature rating of more than 125°C, and better 135°C or more. By combining the solute phase composed of a specific acid and a salt of a specific amine in the solvent, the above characteristics can play an extremely significant role. The specific acid and specific amine used in the present invention are as follows: the specific acid has a total carbon number of more than 12 and must be a long-chain dibasic carboxylic acid. The specific amine must be an amine with a boiling point of more than 150°C. Such long-chain dibasic carboxylic acids are preferably dienoic acids such as dodecane dioic acid, 2-butyloctanedioic acid, isopentanedioic acid, and cyanuric acid.

[0014] Several combinations are possible. Even if the carbon number of the commonly used is less than 12, if it is a highly heat-resistant aromatic carboxylic acid (such as phthalic acid and melamine), it can be used in combination within the range that does not impair the pressure resistance. In addition, alkylamines such as dibutylamine (boiling point 159°C), tripropylamine (boiling point 156°C), tributylamine (boiling point 217°C), aniline (boiling point 184°C), toluidine (boiling point 200°C), N-methylaniline (boiling point 196°C), imidazole (boiling point 256°C) and its medium (including quaternary imidazolinium salt), amide with a ring skeleton (boiling point 240°C), 12-vinyl-8-octadecene dicarboxylic acid (boiling point 261°C) and other amines with amino skeletons, and its medium amines, and its medium (including quaternary ammonium salts) and other aromatic amines and complex amine compounds are suitable as the specific ammonia mentioned here. In particular, it was confirmed that 12-vinyl-8-octadecene dicarboxylic acid (boiling point 261°C) has high thermal stability and has the effect of improving the voltage resistance (spark voltage) of the electrolyte. The amount of amine is relatively small compared to the carboxylic acid, and the pH of the electrolyte is adjusted to 4-8, preferably 4-6.

[0015] The electrolyte content added to the solvent is preferably in the case of isopentanedioic acid of the solute long-chain dibasic carboxylic acid and dichlorocyclohexane of the amine, and the added amount is 10~25% by weight of isopentanedioic acid (denoted as iEDA) relative to 100% by weight of the solvent, preferably in the range of 10-20% by weight, and 12-vinyl-8-octadecene dioic acid (denoted as DBU) is in the range of 0.5-4.0% by weight, preferably 1.0-2.0% by weight.

[0016] The present invention has remarkable high temperature stability and reliability. Even if used for a long time at high temperature, the characteristic change from the initial characteristic is very small. This is related to the composition of the electrolyte of the conductive polymer hybrid electrolytic capacitor. More specifically, it has the characteristics of lead-free reflow soldering heat resistance, high temperature durability exceeding 125°C, and high withstand voltage characteristics above 63V. It maintains the characteristics of low ESR, high ripple current and high capacity, and can also be used in a wide range of rated voltages from 63V to 200V.

[0017] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A solid-liquid hybrid capacitor low-temperature resistant electrolyte, characterized in that: The electrolyte contains a solute, a solvent and an additive, wherein the amount of the ethanol compound in the solvent is 30-85% by weight, the amount of the polyalkylene glycol is 3-10%, and the solute is an amino acid compound.

2. The solid-liquid hybrid capacitor low-temperature resistant electrolyte according to claim 1, characterized in that: The solute is composed of a complex compound of alicyclic dicarboxylic acid, organic acid and inorganic acid, or a complex compound of diethylene glycol and triethylene glycol.

3. The solid-liquid hybrid capacitor low-temperature resistant electrolyte according to claim 1, characterized in that: The solvent is composed of isopentanedioic acid and 12-vinyl-8-octadecene dioic acid.

4. The solid-liquid hybrid capacitor low-temperature resistant electrolyte according to claim 2, characterized in that: The acid in the solute is a long-chain dibasic carboxylic acid with a total carbon number of more than 12; the amine is an amine with a boiling point above 150°C.

5. The solid-liquid hybrid capacitor low-temperature resistant electrolyte according to claim 4, characterized in that: The long-chain dibasic carboxylic acid is one or more of dodecane diacid, 2-butyl octanedioic acid, isopentanedioic acid and dicyanic acid.

6. The solid-liquid hybrid capacitor low-temperature resistant electrolyte according to claim 4, characterized in that: The amine is an aromatic amine, a complex amine compound, or an amide having a cyclic skeleton.