The present invention is directed to a conductive
electrolyte for use in
high voltage electrolytic capacitors and to an
electrolytic capacitor impregnated with the
electrolyte of the present invention for use in an
implantable cardioverter defibrillator (ICD). The
electrolyte according to the present invention is composed of a two
solvent mixture of
ethylene glycol and di(
ethylene glycol); a combination of
boric acid with an aliphatic
dicarboxylic acid of
carbon chain length from eight to thirteen, such as suberic, azelaic, sebacic, undecanedioic, dodecanedioic, or brassylic acid; a
very long chain dicarboxylic acid, where the acid moieties are separated by 34 carbons; and a nitro-substituted aromatic compound as a degassing agent, such as 3-nitroacetophenone or 2-nitroanisole. This electrolyte is then titrated with a light amine such as
ammonia,
diethylamine,
dimethylamine,
trimethylamine, or
triethylamine. The electrolyte according to the present invention, when impregnated in an
electrolytic capacitor, provides an acceptable
breakdown voltage while having a reasonable bulk
conductivity. This electrolyte, when impregnated within a
capacitor constructed of appropriate foils and paper spacers, should provide a part with a working
voltage of at least 500 volts, while having a bulk
conductivity of approximately 3 mS / cm.