Electrolyte for driving ultrahigh voltage large-sized aluminium electrolytic capacitor and solute thereof

Abstract

The invention provides an electrolyte for driving an ultrahigh voltage large-sized aluminium electrolytic capacitor and a solute thereof. The solute of the electrolyte for driving the ultrahigh voltage large-sized aluminium electrolytic capacitor is a high-molecular solute, and the preparation process comprises the following steps of: uniformly mixing a polyalcohol polymer with hydroxyl at a tail end and a saturated or unsaturated binary or polybasic acid according to a certain proportion; adding a certain amount of catalyst; carrying out condensation and esterification reaction at certain temperature under the condition of decompression, cooling, and separating an ester, wherein the total number of carbon atoms positioned on a main chain of the ester is 15 or more than 15; and dissolving the ester into a solvent to prepare a solution with certain concentration, then introducing ammonia so that the pH of the solution reaches a certain range, and stopping introducing the ammonia so that the ester reacts with the ammonia to form ester ammonium salt, wherein the ester ammonium salt is the high-molecular solute used for the electrolyte. The aluminium electrolytic capacitor has very high voltage resistance, larger ripple current bearing and high reliability and finished product ratio when using the electrolyte prepared by the solute.

Description

technical field [0001] The invention relates to an ultra-high-voltage large-scale aluminum electrolytic capacitor, in particular to an electrolytic solution and a solute thereof for driving an ultra-high-voltage large-scale aluminum electrolytic capacitor. Background technique [0002] Aluminum electrolytic capacitors are widely used in filtering, bypassing, coupling, resonance, phase shifting, and energy storage because of their large capacitance per unit volume, small size, light weight, and low price. [0003] With the rapid development of new technologies (such as high-voltage inverters, electric vehicles, wind power and photovoltaic power generation new energy, implanted medical equipment, etc.), higher requirements are put forward for aluminum electrolytic capacitors: (1) The requirements are high Withstand voltage capability (working voltage > 600V, that is, ultra-high voltage aluminum electrolytic capacitor), can withstand high surge voltage, and must work with a ...

AI Technical Summary

Problems solved by technology

[0008] Usually, in order to obtain a high flash voltage, it is generally necessary to add a flash voltage booster, such as polyethylene glycol, ammonium polyacrylate, polyvinyl alcohol borate, polyvinyl alcohol phosphate, nano inorganic oxide particles, poly One or several kinds of ethylene oxide propylene oxide ethers, but these materials themselves have no conductivity and are only used as flash voltage boosters

For aluminum electrolytic capacitors, since the liquid electrolyte is the actual cathode of the aluminum electrolytic capacitor, the conductive carriers of the actual cathode are no longer free electrons but ions, so this additive cannot enhance the ionic conductivity of the electrolyte

[0009] A lot of practical work has proved that the current high-voltage and ultra-high-voltage aluminum electrolytic capacitors, with long-term use, due to the slow chemical reactions of various components in the driving electrolyte, the moisture content increases, the conductivity of the electrolyte decreases, and the loss of the capacitor Increased rate of change of angle factor DF

In addition, the flashover voltage of the electrolyte is reduced, and when the aluminum electrolytic capacitor is loaded at high temperature, the electrode foil will spark and the oxide film will be destroyed, which is also the main cause of anode corrosion.

At the same time, the relevant performance parameters of capacitors deteriorate sharply, resulting in failure, and its reliability cannot meet the needs of capacitor development

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