Electrolytic capacitor

Disclosed is an electrolytic capacitor comprising a capacitor element formed by winding an anode foil having pits with a diameter of not less than 0.1 mu m formed on the surface thereof and a cathode foil with a separator provided interposed therebetween, the separator having been coated with PVA which is then dried, the capacitor element being in contact with an electrolytic solution for electrolytic capacitor containing ethylene glycol, whereby the electrolytic solution is gelled. An electrolytic capacitor which comprises a capacitor element formed by winding an anode foil and a cathode foil with a separator provided interposed therebetween, the separator having been prepared by mixing filament fibers formed by extruding PVA solution into a gas, the capacitor element being impregnated with an electrolytic solution, is also disclosed. An electrolytic capacitor which is prepared by a process which comprises impregnating a capacitor element formed by winding an anode foil, a cathode foil and a separator with a driving electrolytic solution, inserting the capacitor element into an outer case, sealing the opening of the outer case with a sealing member, and then subjecting the anode to reformation, wherein the driving electrolytic solution contains boric acid and a polyvinyl alcohol is attached to at least both the upper and lower end faces of the capacitor element, is further disclosed. Proper selection of the form of PVA in the electrolytic capacitor of the present invention allows PVA dissolved in the electrolytic solution to effectively act on the electrode foil, making it possible to improve the withstand voltage and overvoltage resistance without raising the dielectric loss of the electrolytic capacitor.