Electrolyte for medium and low voltage of electrolytic capacitor and preparation method of electrolyte

Abstract

The invention discloses an electrolyte for the medium and low voltage of an electrolytic capacitor and a preparation method of the electrolyte. The electrolyte includes, by weight, 5 to 10 parts of chloroactic acid, 1 to 4 parts of polyethylene glycol, 10 to 20 parts of ethyl alcohol, 3 to 7 parts of acetic anhydride, 5 to 10 parts of phthalic acid, 1 to 3 parts of potassium biphthalate, 2 to 6 parts of maleic anhydride, 1 to 5 parts of vinyl cyanide, 0.5 to 1 part of potassium bisulfite, 0.3 to 0.8 part of nitrophenol, 0.1 to 0.5 part of ammonium persulfate, 1 to 4 parts of acrylamide and 3 to 8 parts of sebacic acid. The preparation method includes the steps that all constituents are mixed, so that mixed liquid is acquired, inert gas is blown into the mixed liquid, oxygen in the mixed liquid is exhausted, the temperature is increased for conducting a reaction, the temperature is then decreased to indoor temperature, and therefore the electrolyte is acquired. The electrolyte is suitable for the medium and low voltage conditions, good in electricity conductive performance and long in service life.

Description

technical field [0001] The invention belongs to the technical field of chemical electrolyte preparation, and in particular relates to an electrolyte for medium and low voltage of an electrolytic capacitor and a preparation method thereof. Background technique [0002] Solvents commonly used in electrolytes include dimethylformamide, γ-butyrolactone, ethylene glycol, glycerol, water, etc. Dimethylformamide is a solvent for military capacitors, and it has a wide operating temperature range. In Asia, γ-butyrolactone is also popular as an electrolyte solvent, mainly used in low-voltage small capacitors, and capacitors using this solvent as the main solvent have lower ESR. Ethylene glycol is the most widely used solvent, and low-voltage capacitors usually use ethylene glycol plus some water as the solvent system. The solute in the electrolyte is mainly boric acid, borate, carboxylate and a small amount of other inorganic salts and depolarizing hydrogen remover, corrosion inhibi...

AI Technical Summary

Problems solved by technology

Linear dicarboxylic acids have a tendency to crystallize at low temperatures, and the operating temperature range of capacitors is restricted. These problems have become a major obstacle in the manufacture of medium and high voltage, low impedance, wide temperature range, and long-life electrolytic capacitors.

The third generation: straight-chain carboxylate + ethylene glycol system, the leakage current of aluminum electrolytic capacitors is significantly improved compared with the second-generation electrolyte, but the carboxylate flash fire rises due to the increase in molecular weight, but its dissolution drop in volume

The fourth generation: branched-chain carboxylate + ethylene glycol system, branched-chain carboxylate replaces or partially replaces straight-chain carboxylate, branched-chain carboxylate has a large solubility and better thermal stability, but the cost is generally higher

[0004] At present, the types of electrolytes have been used in a variety of ways, which can meet different electrolysis requirements, such as electrolytes suitable for different voltage conditions, etc., but the electrolytes suitable for medium and low voltages have problems of poor conductivity and service life, so it needs to be tested. Further research and development of electrolytes with better performance