Electrolytic capacitor

Abstract

Provide is an electrolytic capacitor for a middle-to-high voltage application that is equal to or higher than 100 V which suppresses the total amount of gas to be produced in the electrolytic capacitor. The anode foil of the electrolytic capacitor includes an enlarged surface portion provided with tunnel-shape pits formed from the foil surface in the thickness direction of the foil, and a dielectric oxide film formed on the surface of the enlarged surface portion. The cathode body of the electrolytic capacitor includes a cathode foil formed of a valve acting metal, and a carbon layer formed on the cathode foil.

1 . An electrolytic capacitor comprising an anode foil and a cathode body,
 wherein the anode foil comprises:   an anode-side enlarged surface portion formed on a surface of the foil; and   a dielectric oxide film formed on a surface of the enlarged surface portion, and   wherein the cathode body comprises:   a cathode foil formed of a valve acting metal; and   a carbon layer formed on the cathode foil.   
     
     
         2 . The electrolytic capacitor according to  claim 1 , wherein the anode-side enlarged surface portion is provided with tunnel-shape pits formed from the surface of the foil in a thickness direction of the foil. 
     
     
         3 . The electrolytic capacitor according to  claim 1 , wherein:
 the cathode body comprises a cathode-side enlarged surface portion formed on a surface of the cathode foil; and   the carbon layer is formed on the cathode-side enlarged surface portion.   
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The electrolytic capacitor according to  claim 1 , further comprising:
 a component comprising the anode foil and the cathode body; and   an electrolyte filled in the element,   wherein no nitro-based compound is contained in the electrolyte.   
     
     
         8 . The electrolytic capacitor according to  claim 1 , wherein:
 the cathode body comprises an insulation layer formed on a surface of the foil; and   the carbon layer is formed on the insulation layer.   
     
     
         9 . (canceled) 
     
     
         10 . The electrolytic capacitor according to  claim 1 , further comprising:
 a component comprising the anode foil and the cathode body; and   an electrolyte which comprises a solvent containing ethylene glycol and which is filled in the element.   
     
     
         11 . The electrolytic capacitor according to  claim 2 , wherein some of or all of the tunnel-shaped pits pass completely through the anode foil. 
     
     
         12 . The electrolytic capacitor according to  claim 1 , utilized for a middle-to-high voltage application that is equal to or higher than 100 V. 
     
     
         13 . The electrolytic capacitor according to  claim 2 , wherein:
 the cathode body comprises a cathode-side enlarged surface portion formed on a surface of the cathode foil; and   the carbon layer is formed on the cathode-side enlarged surface portion.   
     
     
         14 . The electrolytic capacitor according to  claim 13 , wherein the carbon layer and the cathode-side enlarged surface portion are in contact with each other by pressing. 
     
     
         15 . The electrolytic capacitor according to  claim 14 , wherein the carbon layer enters the cathode-side enlarged surface portion. 
     
     
         16 . The electrolytic capacitor according to  claim 15 , wherein:
 the cathode-side enlarged surface portion is provided with sponge-like pits; and   a carbon material of the carbon layer enters the sponge-like pits.   
     
     
         17 . The electrolytic capacitor according to  claim 13 , wherein the carbon layer enters the cathode-side enlarged surface portion. 
     
     
         18 . The electrolytic capacitor according to  claim 17 , wherein:
 the cathode-side enlarged surface portion is provided with sponge-like pits; and   a carbon material of the carbon layer enters the sponge-like pits.   
     
     
         19 . The electrolytic capacitor according to  claim 2 , utilized for a middle-to-high voltage application that is equal to or higher than 100 V. 
     
     
         20 . The electrolytic capacitor according to  claim 3 , wherein the carbon layer and the cathode-side enlarged surface portion are in contact with each other by pressing. 
     
     
         21 . The electrolytic capacitor according to  claim 20 , wherein the carbon layer enters the cathode-side enlarged surface portion. 
     
     
         22 . The electrolytic capacitor according to  claim 21 , wherein:
 the cathode-side enlarged surface portion is provided with sponge-like pits; and   a carbon material of the carbon layer enters the sponge-like pits.   
     
     
         23 . The electrolytic capacitor according to  claim 3 , wherein the carbon layer enters the cathode-side enlarged surface portion. 
     
     
         24 . The electrolytic capacitor according to  claim 20 , utilized for a middle-to-high voltage application that is equal to or higher than 100 V.