Electrolyte of medium-high voltage aluminum electrolytic capacitor and preparation method of solute thereof

Abstract

The invention relates to electrolyte of a medium-high voltage aluminum electrolytic capacitor and a preparation method of solute thereof. In order to solve the problems of low sparking voltage, poor thermal stability and bad solubility in the traditional electrolyte, the invention provides the electrolyte containing dicarboxylic acid having a branched chain or salt thereof as a solute and a single solvent or a mixed solvent containing more than one selected from alcohols, alcohols and ethers, amides, sulfones, sulfoxides and esters, wherein the mass percentage of the solute is 0.5-30 percent. The dicarboxylic acid having a branched chain is prepared by evenly mixing and reacting a reactant (formula is shown upper right) (A, B are electron withdrawing groups, and R1 is a branched chain) and acrylic acid derivative and catalyzer alkali, saponifying, acidizing by strong acid, decarboxylating and washing by purified water. Ammonium salt is produced if required by dicarboxylic acid containing ether group reacting with ammonia or amine. The electrolyte prepared with acid or salt thereof in the invention has better solubility and thermal stability.

Description

technical field [0001] The invention relates to a method for preparing an electrolyte solution of an electrolytic capacitor and a solute thereof, in particular to a method for preparing an electrolyte solution and a solute thereof of a medium-high voltage aluminum electrolytic capacitor. Background technique [0002] The known electrolytic solution of medium and high voltage electrolytic capacitors for aluminum electrolytic capacitors uses ethylene glycol as a solvent, and inorganic compounds such as boric acid or ammonium pentaborate as the main solute, and then uses azelaic acid, sebacic acid, and dodecanedioic acid as the main solute. And its ammonium salt as the main solute of the electrolyte, and the above inorganic salts and organic acid salts are also used as the solute. Such an electrolyte has poor stability at a high temperature of 105 degrees Celsius or above. The rate drops rapidly, which affects the performance and life of the capacitor. Among them, boric acid o...

AI Technical Summary

Problems solved by technology

[0002] The known electrolytic solution of medium and high voltage electrolytic capacitors for aluminum electrolytic capacitors uses ethylene glycol as a solvent, and inorganic compounds such as boric acid or ammonium pentaborate as the main solute, and then uses azelaic acid, sebacic acid, and dodecanedioic acid as the main solute. And its ammonium salt as the main solute of the electrolyte, and the above inorganic salts and organic acid salts are also used as the solute. Such an electrolyte has poor stability at a high temperature of 105 degrees Celsius or above. The rate drops rapidly, which affects the performance and life of the capacitor

Among them, boric acid or its salt will react with ethylene glycol at high temperature to produce water, which will affect the life of the capacitor, while ammonium sebacate and ammonium dodecanoate have low solubility in ethylene glycol, and do not exceed 6 at room temperature. %, poor low temperature performance

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