Enhancement of the sustaining voltage of aluminum electrolytic capacitors by the addition of silica organo-sols into their nonaqueous electrolyte solutions

The sustaining voltage of aluminum electrolytic capacitors can be enhanced by the addition of colloidal silica into their operating nonaqueous electrolyte solutions. A systematic study on the effects of colloidal silica on the scintillation voltage of aluminum electrolytic capacitors was carried out using silica organo-sols dispersed in ethylene glycol and quaternary ammonium carboxylate/γ-butyrolactone solutions. It was confirmed that maintaining the dispersed state of nano-particles in electrolytes so as not to cause gelation is the prime requirement as a sustaining voltage booster. The synergetic effect of organo-phosphorous acids was also examined.