Non-symmetric capacitor

Abstract

A capacitor having an electrochemical cathode electrode, an electrolytic anode electrode, and a substantially non-aqueous electrolyte disposed between the cathode and anode electrodes. The cathode includes a metal and a finely divided material, i.e. a conducting material with a very high ratio of surface area to volume. The anode includes an oxide forming metal and a corresponding metal oxide. The substantially non-aqueous electrolyte is in contact with the finely divided material forming a double layer electrochemical cathode capacitor. The cathode provides the foundation for interleaving a plurality of anodes with a plurality of cathodes. Insulating layers separate the interleaved anodes from the cathodes.

What is claimed is:  
     
         1 . A capacitor of the type having a cathode and an anode and an electrolyte disposed between the cathode and the anode, the capacitor comprising 
 an electrochemical cathode comprising a metal coated with a finely divided material,    an electrolytic anode comprising an oxide forming metal and a corresponding metal oxide, and    a substantially non-aqueous electrolyte in contact with the finely divided material on the cathode and the metal oxide on the anode.    
     
     
         2 . The capacitor of  claim 1  wherein a double layer of charge is formed at the interface between the finely divided material and the substantially non-aqueous electrolyte.  
     
     
         3 . The capacitor of  claim 1  wherein the cathode comprises a metal selected from the group consisting of nickel, titanium, platinum, other noble metals, other non-oxidizing metals and metals forming a conducting or semiconducting oxide.  
     
     
         4 . The capacitor of  claim 1  wherein the anode comprises aluminum coated with aluminum oxide.  
     
     
         5 . The capacitor of  claim 1  wherein the anode comprises a metal selected from the group consisting of tantalum, niobium, zirconium, titanium, and alloys thereof.  
     
     
         6 . The capacitor of  claim 1  wherein the finely divided material is selected from the group consisting of activated carbon powder, carbon fibers, and graphite.  
     
     
         7 . The capacitor of  claim 1  wherein the substantially non-aqueous electrolyte comprises an ethylene glycol solvent mixture with additives.  
     
     
         8 . The capacitor of  claim 1  wherein the substantially non-aqueous electrolyte comprises a butyrolactone solvent mixtures with additives.  
     
     
         9 . The capacitor of  claim 1  wherein the anode has a larger surface area than the cathode.  
     
     
         10 . The capacitor of  claim 1  wherein the cathode comprises an expanded nickel mesh.  
     
     
         11 . The capacitor of  claim 1  further comprising a separator separating the electrolytic anode from the electrochemical cathode.  
     
     
         12 . The capacitor of  claim 11  wherein the separator comprises kraft, manila, hemp papers, and composites thereof.  
     
     
         13 . The capacitor of  claim 11  wherein the separator comprises a composite of paper and polypropylene fibers.  
     
     
         14 . The capacitor of  claim 1  wherein the anode comprises a metal foil wound into a roll.  
     
     
         15 . The capacitor of  claim 1  wherein the anode comprises a flattened aluminum wire wound into a roll.  
     
     
         16 . The capacitor of  claim 1  comprising a plurality of parallel connected capacitors, each capacitor comprising an electrochemical cathode, an electrolytic anode, and a substantially non-aqueous electrolyte.  
     
     
         17 . The capacitor of  claim 16  further comprising separators electrically separating the anodes from the cathodes.  
     
     
         18 . A capacitor of the type having a cathode and an anode and an electrolyte disposed between the cathode and the anode, the capacitor comprising 
 a plurality of electrochemical cathodes,    a plurality of electrolytic anodes interleaved with the electrochemical cathodes,    a plurality of separators separating the cathodes from the anodes,    an electrolyte disposed between the cathodes and anodes, and    wherein the plurality of anodes and cathodes form a plurality of parallel connected capacitors.    
     
     
         19 . The capacitor of  claim 18  wherein the electrolyte is substantially non-aqueous.  
     
     
         20 . The capacitor of  claim 18  wherein each electrochemical cathode comprises a metal having top and bottom surfaces coated with a finely divided material.  
     
     
         21 . The capacitor of  claim 18  wherein each electrolytic anode comprises a metal and a corresponding metal oxide.  
     
     
         22 . The capacitor of  claim 18  further comprising a cathode lead electrically connecting the cathodes to each other and to a cathode terminal.  
     
     
         23 . The capacitor of  claim 18  further comprising an anode lead electrically connecting the anodes to each other and to an anode terminal.  
     
     
         24 . The capacitor of  claim 18  wherein the anode is formed as a stack of individual metal sheets.  
     
     
         25 . The capacitor of  claim 24  further comprising a collector strip connecting the individual metal sheets to each other.  
     
     
         26 . An electrolytic capacitor comprising an anode, said anode comprising a stack of individual metal sheets electrically connected to each other.  
     
     
         27 . An AC start capacitor comprising 
 a first electrolytic anode,    a second electrolytic anode,    a floating electrochemical cathode interleaved between the first and second electrolytic anodes,    an electrolyte, and    wherein said first and second electrolytic anodes comprise a metal and a corresponding metal oxide, said electrochemical cathode comprises a metal having top and bottom surfaces coated with a finely divided material and an AC voltage is connected to said first and second electrolytic anodes.    
     
     
         28 . The capacitor of  claim 27  wherein the electrolyte is substantially non-aqueous.  
     
     
         29 . The capacitor of  claim 27  further comprising separators separating the first and second anode from the floating cathode.  
     
     
         30 . A method of forming a capacitor electrode comprising 
 transporting a continuous sheet of metal,    cutting pieces of the metal sheet at spaced intervals,    stacking the pieces of the metal, and    welding the stacked pieces of the metal.    
     
     
         31 . A method of forming a capacitor comprising 
 fabricating a plurality of anodes by transporting a continuous sheet of a first metal, cutting pieces of the first metal sheet at spaced intervals, stacking the pieces of the first metal, and welding the stacked pieces of the first metal,    fabricating a plurality of cathodes by transporting a continuous sheet of a second metal, and cutting pieces of the second metal, and    interleaving the anodes and cathodes, while separating them with insulating separators.    
     
     
         32 . The capacitor of  claim 1  wherein the cathode comprises a titanium sheet.  
     
     
         33 . The capacitor of  claim 32  wherein the cathode comprises a hydrated amorphous ruthenium oxide coating applied to the titanium sheet.  
     
     
         34 . The capacitor of  claim 18  wherein a plurality of anodes are arranged in a first layer, and a plurality of cathode areas are arranged in a second layer with the cathode areas approximately aligned with the anodes.  
     
     
         35 . The capacitor of  claim 34  wherein the plurality of anodes comprises wound aluminum anodes in the shape of disks.  
     
     
         36 . The capacitor of  claim 35  wherein the plurality of cathode areas comprise hydrated amorphous ruthenium oxide areas applied to a titanium sheet.