An ultracapacitor that is in contact with a hot atmosphere having a temperature of about 80° C. or more is provided. The ultracapacitor contains a first electrode, second electrode, separator, nonaqueous electrolyte, and housing is provided. The first electrode comprises a first current collector electrically coupled to a first carbonaceous coating and the second electrode comprises a second current collector electrically coupled to a second carbonaceous coating. The capacitor exhibits a capacitance value within the hot atmosphere of about 6 Farads per cubic centimeter or more as determined at a frequency of 120 Hz and without an applied voltage.