Highly aqueous and high-stability electrolyte used for aluminum electrolytic capacitor and preparation method therefor

Abstract

The present invention relates to the technical field of electrolytes, in particular to a highly aqueous and high-stability electrolyte used for an aluminum electrolytic capacitor and a preparation method therefor. The electrolyte comprises the following raw materials in parts by weight: 10-14 parts of ammonium adipate, 6-10 parts of a water-proofing agent, 4.5-7 parts of ammonia, 3-5 parts of ammonium formate, 1-2 parts of p-nitrobenzoic acid, 0.5-1 part of phosphoric acid, 6-10 parts of glycol and 50-70 parts of deionized water. The electrolyte is prepared by means of interaction among the raw materials and by strictly controlling a weight proportion of the raw materials; the sparking voltage of the prepared electrolyte can reach 102 V and the conductivity rate of the prepared electrolyte can reach 100 ms/cm; and the electrolyte has good electrochemical properties, has the advantages of high frequency, low impedance and high stability, and can be applied to manufacturing of the aluminum electrolytic capacitors.

Description

technical field [0001] The invention relates to the technical field of electrolytic solutions, in particular to an electrolytic solution for high-water system and high-stability aluminum electrolytic capacitors and a preparation method thereof. Background technique [0002] Aluminum electrolytic capacitors are one of the basic components of electronic products. With the continuous improvement of the quality of electronic products and the expansion of the application range of aluminum electrolytic capacitors, higher requirements are put forward for their performance. Electronic products such as switching power supplies and energy-saving lamps have high requirements on the safety performance of high-voltage electrolytic capacitors. In the filter circuit, the capacitor is subjected to high voltage and high ripple current. If the power supply is unstable or overvoltage is applied, the capacitor will be damaged, catch fire, burn and other accidents. The electrolyte of an alumin...

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Problems solved by technology

The working electrolyte prepared in this way has the problem of low conductivity, and boric acid and its salts are easy to undergo esterification reaction with ethylene glycol at high temperature to generate a large amount of condensed water, which causes the moisture content inside the electrolyte to increase, and the electrolyte's The vapor pressure increases, and the internal pressure of the capacitor increases, causing the capacitor to open the valve and fail; 2. Using ethylene glycol as the main solvent, using direct-linked hydrocarbon saturated dicarboxylic acids such as azelaic acid, sebacic acid or dodecanedioic acid and their Salt is the electrolyte of the electrolyte. Although this type of electrolyte avoids a part of the esterification reaction, due to the low solubility of this type of straight-chain alkanes in ethylene glycol, the impedance of the product is large and the ripple is large. It is easy to generate heat under high temperature and make the solvent volatilize, thus creating a vicious cycle, causing the capacitor to dry out and fail. At the same time, linear alkanes are prone to amidation side reactions at high temperatures to generate water, which is also easy to cause early failure of the capacitor; 3. Use some branched chains Acids or their salts, such as reported 1,6-DDA and its salts and 2-butylsuberic acid and its salts, such branched carboxylic acids and their salts have improved solubility in solvents compared to straight-chain alkanes , thus producing effects to a certain extent, but at the same time, this kind of acid or its salt mainly relies on imports, so the cost is high and there are many constraints