An electrolytic solution for an electrolytic capacitor is disclosed, comprising a basic solution comprising a mixed solvent of .gamma.-butyrolactone and ethylene glycol having dissolved therein a quaternary alkylammonium salt of phthalic acid, maleic acid or benzoic acid as a solute, the basic solution further containing from 0.5 to 10 parts by weight of colloidal silica and from 0.5 to 8 parts by weight of at least one phosphorus compound selected from dialkyl phosphate and phosphorous acid, per 100 parts by weight of the basic solution. The electrolytic solution has an increased dielectric strength while retaining high conductivity.
An electrolyte for activating an electrolytic or electrochemical capacitor is described. The electrolyte preferably includes a mixed solvent of water and ethylene glycol having an ammonium salt dissolved therein. An acid such as phosphoric or acetic acid is used to provide a pH of about 3 to 6. The electrolyte is particularly useful for activating a ruthenium oxide/tantalum capacitor having an anode breakdown voltage in the range of 175 to 300 volts.
A non-aqueous electrolyte comprises an organic solvent and a solute, and also has an electrolytic conductivity that is greater than or equal to 1 mS/cm but less than or equal to 100 mS/cm. This solute preferably includes at least one of a carboxylate and a salt of inorganic oxoacid. In addition, the non-aqueous electrolyte preferably comprises water in a proportion of 1 to 10 wt %. In an MIM nonlinear element (20), an insulated film (24) is formed by anodic oxidation using the above non-aqueous electrolyte. In addition, the insulated film comprises at least one of carbon atoms and atoms of families 3 to 7 that were originally the central atoms of the salt of inorganic oxoacid, and has a relative permittivity of 10 to 25. With this MIM nonlinear element, the capacitance is sufficiently small, the steepness of the voltage-current characteristic is sufficiently large, and also the resistance is sufficiently uniform over a wide area.