Abstract:
A capacitor having a cylindrical shape or configuration so that it is capable of being inserted directly into the vasculature of a patient is described. A typical diameter for the present capacitor is about 6 mm. A capacitor of this size would occupy about 9% of the total cross-sectional area of the inferior vena cava prior to the crossover to the heart, where the typical diameter of the vein is about 20 mm. The crossover section has a diameter of about 11 mm to about 12 mm.

Description:
BACKGROUND OF THE INVENTION 
   The present invention generally relates to a capacitor and, more particularly, to a cylindrical capacitor. The benefit of a cylindrical configuration means that the capacitor is capable of being inserted into the vasculature of a patient. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a capacitor having a cylindrical shape or configuration. This means that the capacitor is capable of being inserted into the vasculature. A typical diameter for the present capacitor is about 6 mm. A capacitor of this size would occupy about 9% of the total cross-sectional area of the inferior vena cava prior to the crossover to the heart, where the typical diameter of the vein is of about 20 mm. The crossover section has a diameter of about 11 mm to about 12 mm. In that respect, new and innovated methods and techniques for treating abnormal heart function are proposing that a cylindrically shaped capacitor or string of capacitors can be positioned in a patient&#39;s vasculature, particularly the inferior vena cava, for the treatment of tachyarythmias. 
   These and other aspects of the present invention will become more apparent to those skilled in the art by reference to the following description and to the appended drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an isometric view of a capacitor  10  according to the present invention. 
       FIG. 2  is a plan view of a header  40  for the capacitor. 
       FIG. 3  is a cross-sectional view along  3 — 3  of  FIG. 2 . 
       FIG. 4  is a side elevational view, partly broken away, showing the header  40  of  FIGS. 2 and 3  supporting a terminal pin  36  in a glass-to-metal seal  42 . 
       FIG. 5  is a side elevational view showing an anode pellet including an anode wire  34  extending there from. 
       FIG. 6  is a side elevational view showing two anode pellets  14  and  16  as in  FIG. 5  aligned in a side-by-side relationship and having their anode wires  34 A,  34 B connected to the terminal pin  36  supported in the glass-to-metal seal  42  of the header  40 . 
       FIG. 7  is a side elevational view showing the side-by-side anode pellets  14 ,  16  of  FIG. 6  having their anode wires  34 A,  34 B connected to the terminal pin  36  and encased in a polymeric material  65 . 
       FIG. 8  is a cross-sectional view along  8 — 8  of  FIG. 7 . 
       FIG. 9  is a plan view of a cathode  18  for the capacitor. 
       FIG. 10  is an upper end elevational view of the cathode  18  of  FIG. 9 . 
       FIG. 11  is a side elevational view of the cathode  18  partially folded into its final shape. 
       FIG. 12  is an end elevational view of the partially folded cathode of  FIG. 11 . 
       FIG. 13  is a side elevational view of the electrode assembly for the capacitor including the side-by-side anode pellets  14 ,  16  and the cathode  18  fitted to the header  40 . 
       FIG. 14  is a cross-sectional view along line  14 — 14  of  FIG. 13 . 
       FIG. 15  is a side elevational view of a casing tube  92  for the capacitor. 
       FIG. 16  is a side elevational view, partly in phantom, showing the electrode assembly housed inside the casing tube  92 . 
       FIG. 17  is a cross-sectional view along line  17 — 17  of  FIG. 16 . 
       FIG. 18  is a plan view of a lower lid  94  for the casing tube  92 . 
       FIG. 19  is a cross-sectional view along line  19 — 19  of  FIG. 18 . 
       FIG. 19A  is a cross-sectional view of an alternate embodiment of the lower lid  90 A for the casing tube  88 . 
       FIG. 19B  is a cross-sectional view of the lower lid  90 A having its electrolyte fill line  104 A hermetically sealed by laser welding. 
       FIG. 20  is a partial isometric view of another embodiment of an electrode assembly  120  comprising a cylindrically shaped anode pellet  122  surrounded by a cathode  124  according to the present invention. 
       FIG. 21  is a partial isometric view of another embodiment of an electrode assembly  140  comprising a cylindrically shaped anode pellet  142  in electrical association with a pair of cathodes  144 ,  146 . 
       FIG. 22  is a plan view of an alternate embodiment of a cathode  18 A for the capacitor. 
       FIG. 23  is an upper end elevational view of the cathode  18 A of  FIG. 22 . 
       FIG. 24  is an end elevational view of the cathode  18 A partially folded into its final shape. 
       FIG. 25  is a cross-sectional view similar to that of  FIG. 14 , but with the cathode  18 A comprising part of the electrode assembly for the capacitor. 
       FIG. 26  is a cross-sectional view showing the electrode assembly of  FIG. 25  housed inside the casing tube  88 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to the drawings,  FIG. 1  shows a capacitor  10  particularly constructed for insertion into the vasculature of a patient. The capacitor  10  has an outside diameter of about 6 mm. This makes it well suited for positioning in the inferior vena cava without unduly obstructing blood flow there through. 
   The capacitor  10  comprises an anode assembly  12  of two side-by-side anode pellets  14  and  16  ( FIGS. 6 to 8 ), each of an anode active material, and a cathode  18  ( FIGS. 9 to 12 ) of a cathode active material  20  supported on a conductive substrate  22 . The anode assembly  12  and cathode  18  are hermetically sealed inside a casing  24  and operatively associated with each other by a working electrolyte (not shown) contained inside the casing, as will be described in detail hereinafter. The capacitor  10  is of an electrolytic type with the cathode  18  comprising the conductive substrate  22  supporting the active material  20  having capacitive properties. 
   Each of the anode pellets  14  and  16  is of a powdered metal selected from the group consisting of tantalum, aluminum, titanium, niobium, zirconium, hafnium, tungsten, molybdenum, vanadium, silicon, germanium, and mixtures thereof in the form of a pellet. The preferred metal is tantalum powder compressed into a shaped structure having a semi-circular or curved sidewall  26  meeting a planar sidewall  28 . The sidewalls  26  and  28  extend to opposed planar end walls  30  and  32  disposed normal to the longitudinal axis of the anode pellets. Embedded anode wires  34 A and  34 B extend from the respective end walls  30 . The anode wires  34 A,  34 B preferably comprise the same material as the anode active material and are bent so that their distal ends are aligned adjacent to the plane of sidewalls  28  ( FIG. 7 ). 
   The anode pellets  14 ,  16  are sintered under a vacuum at high temperatures and then anodized in a suitable electrolyte. The anodizing electrolyte fills the pores of the pressed powder bodies and a continuous dielectric oxide is formed thereon. In that manner, the anode pellets  14 ,  16  and their extending wires  34 A,  34 B are provided with a dielectric oxide layer formed to a desired working voltage. The anodes can also be of an etched aluminum, niobium, or titanium foil. 
   After anodizing to the desired formation voltage, the anodes  14 ,  16  and extending wires  34 A,  34 B are aligned in the side-by-side relationship shown in  FIGS. 6 to 8  with their respective planar sidewalls  28  facing each other. The distal ends of the anode wires  34 A,  34 B are now spaced from each other by a relatively small gap. The dielectric oxide is then removed from the distal ends of the anode wires  34 A,  34 B and there they are connected to an anode lead  36  supported in a header  40  by an insulative glass-to-metal seal  42  (GTMS). 
   The header  40  is illustrated in  FIGS. 2 to 4  as a unitary metal member such as of titanium having a cylindrical shape in cross-section and comprising an upper planar surface  44  spaced from a lower planar surface  46 . Between the planar surfaces  44 ,  46 , the header  40  has an outer diameter  48  leading to a step  50  that joins to a frusto-conical portion  52  that steps down to an inner diameter portion  54 . A ferrule  56  for the GTMS is integral with the header and has a cylindrical sidewall spaced inwardly from the inner diameter portion  54  and comprising a lower side  58  spaced below the lower header surface  46 . An annular channel  60  recessed into the header upper surface  44  surrounds the upper end of the ferrule  56 , which is co-planar with the upper header surface  44 . 
   The GTMS  42  comprises the ferrule  56  defining an internal cylindrical through bore or passage  62  of constant inside diameter. An insulative glass  64  (shown in phantom in  FIG. 6 ) provides a hermetic seal between the bore  62  and the anode lead  36  passing there through. The anode lead  36  is a cylindrically shaped pin having a proximal portion  36 A that is sandwiched between the spaced apart distal ends of the anode wires  34 A,  34 B extending from the anode pellets  14 ,  16 . The anode lead  36  is connected to the anode wires  34 A,  34 B such as by laser welding. The glass  64  is, for example, ELAN® type  88  or MANSOL™ type  88 . To provide support against shock and vibration conditions, a relatively fast curing polymeric material  65  such as a polyolefin, a fluoropolymer, a hot melt adhesive, or a UV curable adhesive is filled into the space between the opposed planar end walls  30  of the anode pellets  14 ,  16  and the lower surface  46  to the edge forming the inner diameter portion  54  of the header. A relatively slow curing silastic material is also useful. In the final capacitor assembly, the GTMS  42  electrically insulates the anode lead  36  connected to the anode wires  34 A,  34 B from the metal header  40 , which comprises part of the casing  24 . 
   A separator  66  of electrically insulative material in the shape of a bag completely surrounds and envelops each anode pellet  14 ,  16  except their respective extending wires  34 A,  34 B. The separator  66  prevents an internal electrical short circuit between the anode pellets  14 ,  16  of the anode assembly  12  and cathode active materials  20  in the assembled capacitor and has a degree of porosity sufficient to allow flow there through of the working electrolyte during the electrochemical reaction of the capacitor  10 . Illustrative separator materials include woven and non-woven fabrics of polyolefinic fibers including polypropylene and polyethylene or fluoropolymeric fibers including polyvinylidene fluoride, polyethylenetetrafluoroethylene, and polyethylenechlorotrifluoroethylene laminated or superposed with a polyolefinic or fluoropolymeric microporous film, non-woven glass, glass fiber materials and ceramic materials. Suitable microporous films include a polyethylene membrane commercially available under the designation SOLUPOR® (DMS Solutech), a polytetrafluoroethylene membrane commercially available under the designations EXCELLERATOR™ (W.R. Gore), ZITEX® (Chemplast Inc.), a polypropylene membrane commercially available under the designation CELGARD® (Celanese Plastic Company, Inc.), and a membrane commercially available under the designation DEXIGLAS® (C.H. Dexter, Div., Dexter Corp.). Cellulose based separators also typically used in capacitors are contemplated by the scope of the present invention. Depending on the electrolyte used, the separator can be treated to improve its wettability, as is well known by those skilled in the art. 
   As particularly shown in  FIG. 9 , the cathode  18  comprises the conductive substrate  22  coated with the cathode active material  20  in selected locations. The substrate  22  is of a material selected from titanium, tantalum, nickel, molybdenum, niobium, cobalt, stainless steel, tungsten, platinum, palladium, gold, silver, copper, chromium, vanadium, aluminum, zirconium, hafnium, zinc, iron, and mixtures and alloys thereof. Preferably, the substrate is of titanium and is from about 0.0005 inches to about 0.02 inches thick, preferably about 0.001 inches thick. 
   The cathode active material  20  has a thickness of about a few hundred Angstroms to about 0.1 millimeters directly coated on the conductive substrate  22 . In that respect, the conductive substrate  22  may be of an anodized-etched conductive material, have a sintered active material with or without oxide contacted thereto, be contacted with a double layer capacitive material, for example a finely divided carbonaceous material such as activated graphite or activated carbon black, a redox, pseudocapacitive or an under potential material, or be an electroactive conducting polymer such as polyaniline, polypyrole, polythiophene, polyacetylene, and mixtures thereof. 
   According to one preferred aspect of the present invention, the redox or cathode active material  20  includes an oxide of a metal, the nitride of the metal, the carbon nitride of the metal, and/or the carbide of the metal, the oxide, nitride, carbon nitride and carbide having pseudocapacitive properties. The metal is preferably selected from the group consisting of ruthenium, cobalt, manganese, molybdenum, tungsten, tantalum, iron, niobium, iridium, titanium, zirconium, hafnium, rhodium, vanadium, osmium, palladium, platinum, nickel, lead gold, silver, cobalt, and mixtures thereof. The cathode active material  20  can also be an activated carbonaceous material such as carbon nanotubes or amorphous carbon. 
   The substrate  22  comprises opposed major surfaces  22 A and  22 B extending to spaced apart right and left edges  68  and  70  meeting with an upper edge  72  and a lower edge  74 . An upper inlet  76  is provided in the upper edge  72  between the right and left edges  68 ,  70  while a lower inlet  78  is provided in the lower edge  74  centered between the right and left edges. The upper inlet  76  is somewhat deeper than the lower inlet  78 . This provides tabs  80 ,  82  that are used to connect the cathode to the casing serving as the negative terminal, as will be described in detail hereinafter. 
   The cathode active material  20  coats or contacts the conductive substrate  22  at selected locations. As particularly shown in  FIGS. 9 and 10 , a first section  20 A of cathode active material is contacted to the first major surface  22 A of the substrate in a generally rectangular pattern in plan view spaced inwardly a short distance from the left edge of the upper and lower inlets  76 ,  78  and extending toward the right substrate edge  68 . The first cathode active section  20 A has upper and lower edges that are parallel to the upper and lower substrate edges  72 ,  74  and spaced there from. In addition to tab  80 , this configuration forms a right uncoated portion  84  extending from the right active material edge to the substrate edge  68 . 
   A second section  20 B of cathode active material is contacted to the second major substrate surface  22 B in a generally rectangular pattern in plan view spaced inwardly a short distance from the right edge of the upper and lower inlets  76 ,  78  and extending toward the left substrate edge  70 . The second cathode active section  20 B has upper and lower edges that are parallel to the upper and lower substrate edges  72 ,  74  and spaced there from. In addition to tab  82 , this configuration forms a left uncoated portion  86  extending from the left active material edge to the substrate edge  70 . As shown in  FIG. 10 , this provides the first and second cathode active sections  20 A,  20 B having portions aligned in an overlaying relationship with each other on the respective major substrate surfaces  22 A and  22 B extending from the lower edge of the upper inlet  76  to the upper edge of the lower inlet  78 . 
   The pad printing process described in U.S. patent application Ser. No. 10/920,942, filed Aug. 18, 2004, is preferred for making such coatings. Ultrasonically generated aerosol as described in U.S. Pat. Nos. 5,894,403; 5,920,455; 6,224,985; and 6,468,605, all to Shah et al., are also suitable deposition methods. These patents and patent application are assigned to the assignee of the present invention and incorporated herein by reference. 
   To assemble the anode assembly  12  with the cathode  18 , the conductive substrate  22  is folded along the aligned left and right edges of the respective tabs  80  and  82 , and into a generally Z-shaped configuration ( FIG. 12 ). Preferably, a very small gap (not shown) is left in the respective coated sections  20 A,  20 B along the fold lines. This prevents the cathode active material from flaking or sloughing off of the conductive substrate as it is folded. The aligned portions of active sections  20 A and  20 B are next aligned with the gap between the distal end walls  32  of the anode pellets  14 ,  16 . The substrate  22  is then moved along this gap until the upper edge of the cathode active material adjacent to the inlet  76  is aligned with the upper end walls  30  of the anode pellets. 
   The right and left uncoated substrate sections  84 ,  86  are now bent into a curved shape mirroring that of the semi-circular sidewalls  26  of the anode pellets  14 ,  16 . The uncoated sections  84 ,  86  are of a length that is sufficient to overlap a portion of the substrate to form a closed, surrounding construction. In particular, the end of the uncoated section  84  overlaps the substrate opposite the side supporting the second coated section  20 B while the uncoated section  86  overlaps the substrate opposite the side having the first coated section  20 A. As shown in  FIG. 14 , the first cathode active material section  20 A “covers” in an opposing manner the semi-circular sidewall  26  and the planar sidewall  28  of anode pellet  14  while the second cathode active material section  20 B covers the semi-circular sidewall  26  and the planar sidewall  28  of anode pellet  16 . The intermediate separator  66  prevents direct physical contact between the cathode active material sections and the anode pellets. The tabs  80  and  82  abut against the inner step  54  of the header  40  below the frusto-conical section  52 , and are secured in place by laser welding. The lower edge of the cathode active material adjacent to the lower substrate edge  74  is now aligned with the lower end walls  32  of the anode pellets. 
   As shown in  FIGS. 15 to 17 , the thusly-constructed electrode assembly including the header  40  is next fitted to a casing tube  88 . The casing tube  88  is a cylindrically shaped member that is open at both of its ends and made of the same metal as the header  40 , for example titanium. With the electrode assembly housed therein, the upper open-end  88 A of the tube fits into the outer step  50  of the header. Laser welding then hermetically seals the tube  88  to the header  40  at this junction. 
   As shown in  FIG. 16 , the lower ends of the anode pellets  14 ,  16  and the lower edge  14  of the conductive substrate  22  comprising the associated cathode  18  are spaced from the lower open-end  88 B of the tube. A lower lid  90  is fitted in the lower open end of the tube  88  to close the capacitor  10 . The lower lid  90  is a unitary metal member of the same material as the header  40  and casing tube  88 . It has a cylindrical shape in cross-section and comprises an upper planar surface  92  spaced from a lower planar surface  94 . Between these surfaces  92 ,  94 , the lid  90  has an outer diameter  96  leading to a step  98  that joins to a frusto-conical portion  100  tapering downwardly and inwardly to the lower surface  94 . The step  98  is sized to fit into the lower open-end  88 B of the tube in a snug-fitting relationship and is hermetically sealed therein, preferably by laser welding. In that manner, the header  40  closing the upper open end  88 A of the tube  88  and the lower lid  90  closing the lower open end  88 B form the casing  24  for the capacitor  10 . 
   The lower lid  90  is further provided with a beveled annular recess  102  extending into the thickness thereof from the upper planar surface  92 . A bore  104  extends through the thickness of the lower lid  90  and serves as an opening for filling a working electrolyte (not shown) into the casing. After the electrolyte is filled into the capacitor  10 , a frusto-conically shaped plug  106  is sealed in the opening  104  by laser welding to hermetically close the casing  24 . 
     FIGS. 19A and 19B  illustrate an alternate embodiment for hermetically sealing the electrolyte fill opening. In this embodiment, the lower lid  90 A has a bore  104 A of a diameter somewhat less than the previously described bore  104  of lid  90 . Instead of welding a plug into the bore, the bore  104 A is closed by heating the lid material surrounding its perimeter with a laser  108 . 
   The capacitor  10  is completed by the provision of opposite polarity terminal connectors. If desired, a pin  110  is laser welded to the lower lid  90  and serves as the cathode terminal. This pin could be secured to any part of the header  40 , casing tube  88  and lower lid  94  for this purpose. Finally, a sleeve  112  is laser welded to the distal end of the anode wire  36 . The sleeve  112  makes it easier for a user of the capacitor to make this connection. The pin  110  and tube  88  are preferably secured into position by laser welding, spot welding, ultra sonic welding, and the like. 
     FIG. 20  shows an alternate embodiment of an electrode assembly  120  comprising a cylindrically shaped anode  122  surrounded by a cathode  124  according to the present invention. The anode  122  is of a powdered metal selected from the same groups as used to construct anode pellets  14  and  16 . The anode  122  is preferably of tantalum powder compressed into a pellet having a cylindrical sidewall  126  extending to opposed planar end walls (only end wall  128  is shown in the drawing) disposed normal to the longitudinal axis of the pellet. While not shown in the drawing, an embedded wire extends from the anode, preferably from the end wall  128 , for subsequent connection to the anode lead  36 . As before, the anode pellet  122  is sintered under vacuum at high temperatures and then anodized in a suitable electrolyte. The anode wire is now welded to the anode lead  36  of the header  40  before a separator (not shown) of electrically insulative, but ionically conductive material is provided to completely surround and envelope the anode pellet except for the extending anode wire. 
   The cathode  124  comprises a conductive substrate coated with cathode active material  130  selected from the same group as used to construct cathode  18 . Preferably the substrate is of titanium having opposed inner and outer major surfaces  132  and  134  extending to spaced apart right and left edges  136  and  138  meeting with an upper edge  140  and a lower edge (not shown). The cathode active material  130  is preferably ruthenium that coats or contacts the inner surface  132  in a rectangular pattern extending a relatively short distance spaced from the right and left edges  136 ,  138  and a relatively short distance from the upper and lower edges. 
   To assemble the electrode assembly  120 , the cathode substrate is provided in a cylindrical shape surrounding the anode  122  with the cathode active material  130  directly opposite the anode. Laser welding secures the right and left edges  136 ,  138  of the substrate to each other. Although not showing in the drawing, the upper edge  140  of the substrate now abuts against the inner step  54  of the header  40  below its frusto-conical section and is secured in place by laser welding. The cathode substrate could also be welded to the case instead of to the lid. A separator (not shown) prevents direct physical contact between the anode  122  and the cathode  124 . The electrode assembly  120  including the header  40  is then fitted to the casing tube  88  and the remaining steps in building the capacitor proceed as before. 
     FIG. 21  illustrates another embodiment of an electrode assembly  150  comprising a cylindrically shaped anode  152  having an H-shape in longitudinal cross-section and in electrical association with a pair of cathodes  154  and  156  according to the present invention. The anode and cathodes are of similar materials as described above. The tantalum anode pellet  152  has a cylindrical sidewall  158  extending to opposed planar end walls (only end wall  160  is shown) oriented normal to the longitudinal axis of the pellet. A pair of diametrically opposed slots  162  and  164 , which are shown squared-off, but which can also be V-shaped, is formed part way into the thickness of the pellet. The slots  162 ,  164  extend from end wall  160  to the other end wall. An embedded wire (not shown) extends from the anode, preferably from the end wall  160 , for connection to the anode lead  36 . The anode pellet  152  is sintered under a vacuum at high temperature and then oxidized in a suitable electrolyte. The anode wire is next welded to the anode lead  36  of the header  40  before a separator (not shown) of electrically insulative, but ionically conductive material surrounds and envelopes the anode pellet except for the extending anode wire. 
   The pair of cathodes  154  and  156  comprises respective conductive substrates  166  and  168  coated with cathode active material  170 . Substrate  166  comprises opposed inner and outer major surfaces  172  and  174  extending to spaced apart side edges  176  and  178  meeting with an upper edge  180  and a lower edge (not shown). Similarly, substrate  168  comprises opposed inner and outer major surfaces  182  and  184  extending to spaced apart side edges  186  and  188  meeting with an upper edge  190  and a lower edge (not shown). 
   The ruthenium cathode active material  170  coats or contacts the inner surface  172  of substrate  166  in a rectangular pattern extending a relatively short distance spaced from the side edges  176 ,  178  and a relatively short distance from the upper and lower edges. The ruthenium active material  170  also contacts the outer substrate surface  174  a relatively short distance from the side edge  178  toward side edge  186  a distance substantially equal to the depth of slot  162  in the anode pellet. The material also extends a relatively short distance from the upper and lower edges. 
   Similarly, the ruthenium cathode active material  170  coats or contacts the inner surface  182  of substrate  168  in a rectangular pattern extending a relatively short distance spaced from the side edges  186 ,  188  and a relatively short distance spaced from the upper and lower edges. The ruthenium active material also contacts the outer substrate surface  184  a relatively short distance from side edge  188  toward side edge  186  a distance substantially equal to the depth of slot  164 . This active material also extends a relatively short distance from the upper and lower edges. 
   To assemble the electrodes assembly  150 , the side edge  176  of conductive substrate  168  is moved into slot  162  until it substantially occupies this space. The cathode active material  170  on the opposed inner and outer surfaces  172 ,  174  is now directly opposite tantalum anode material. The substrate  166  is now curved about halfway around the circumference of the anode until the side substrate edge  186  is adjacent to the entrance to the other slot  164 . Similarly, the side edge  188  of conductive substrate  168  is moved into slot  164  until it substantially occupies this space. The cathode active material  170  on the opposed inner and outer surfaces  182 ,  184  is directly opposite anode material. As with substrate  166 , this substrate  168  is curved about halfway around the circumference of the anode pellet until its side edge  186  is adjacent to the entrances to the slot  162 . The intermediate separator (not shown) prevents direct physical contact between the respective cathode active materials and the anode pellet. Although not shown in the drawing, the side edges  180 ,  190  of the respective substrates  166 ,  168  now abut against the inner step  54  of the header  40  below the frusto-conical section and are secured in place by laser welding. The electrode assembly  150  including the header  40  is then fitted to the casing tube  88  and the remaining steps in building the capacitor proceed as before. 
     FIGS. 22 to 26  illustrate an alternate embodiment for constructing an electrode assembly  200 .  FIGS. 22 to 24  show a cathode  202  comprising a conductive substrate  204  supporting a cathode active material  206 . The materials of the substrate  204  and cathode active material  206  are the same as those of the previously described for these parts or structures. 
   The substrate  204  comprises approved major surfaces  208  and  210  extending to spaced apart right and left edges  212  and  214  meeting with an upper edge  216  and a lower edge  218 . A cut out  220  is provided at the junction of the right edge  212  and the upper edge  216 . Another cut-out  222  is provided at the junction of the right edge  212  and the lower edge  218 . The upper cut-out  220  is somewhat larger than the lower cut-out  222 . 
   The cathode active material  206  coats or contacts the conductive substrate  204  at selected locations. A first section  206 A of cathode active material is contacted to the first major surface  208  of the substrate in a rectangular pattern in plan view extending from the right edge  212  toward the aligned vertical edges of the cut-outs  220 ,  222 , but spaced therefrom. A second section  206 B of cathode active material is contacted to the second major surface  210  of the substrate in a generally rectangular pattern in plan view extending from the right edge  212  toward the left edge  214 , but spaced therefrom. The second cathode active section  206 B has upper and lower edges that are parallel to the upper and lower substrate edges  216 ,  218  and spaced therefrom. In addition to forming tab  224  and lower edge  226 , this configuration forms a left uncoated portion  204 A of the substrate extending from the left edge of the second active material  206 B to the left substrate edge  214 . As showing in  FIG. 23 , this provides the first and second cathode active sections  206 A,  206 B having portions aligned in an overlaying relationship with each other on the respective major substrate surfaces  208 ,  210  extending from the right substrate edge  212  toward the aligned vertical edges of the cut-outs  220 ,  222 , but spaced therefrom. The previously described pad printing and ultrasonic spraying process are preferred for contacting the cathode active material  206  to the substrate  204 . 
   To assemble the anode assembly  12  with the cathode  202 , the conductive substrate  204  is folded along the aligned right edge of the cut-outs  220 ,  222  into a generally L-shaped configuration ( FIG. 24 ). Preferably, a very small gap (not shown) is left in the coated section  206 B along the fold line. This prevents the cathode active material from flaking or sloughing off of the conductive substrate as it is folded. The aligned portions of the active sections  206 A,  206 B at the second leg of the L-shape is next aligned with the gap between the distal end walls  32  of the anode pellets  14 ,  16 . The substrate  204  is then moved along this gap until the upper edges of the cathode active material sections  206 A,  206 B at the inlet  220  are aligned with the upper end walls  30  of the anode pellets  14 ,  16 . 
   The substrate  204  is now bent into a curved shape mirroring that of the semi-circular sidewalls  26  of the anode pellets  14 ,  16 . The uncoated portion  204 A is of a length that is sufficient to overlap a portion of the substrate adjacent to where the long leg of the L meets the short leg ( FIG. 25 ) to form a closed, surrounding construction. In particular, the uncoated portion  204 A overlaps the substrate opposite the side supporting the second coated section  206 B. 
   As shown in  FIG. 25 , the first cathode active material section  206 A now “covers” in an opposing manner the planar sidewall  28  of anode pellet  14  while the second cathode active material section  206 B covers the semi-circular sidewall  26  and the planar sidewall  28  of anode pellet  16 . Intermediate separators  66 A prevents direct physical contact between the cathode active material sections and the anode pellets. The tab  224  abuts against the inner step  54  of the header  40  below the frusto-conical section  52 , and is secured in place by laser welding. The lower edge of the cathode active material adjacent to the lower substrate edge  226  is now aligned with the lower end walls  32  of the anode pellets. 
   As shown in  FIG. 26 , the thusly-constructed electrode assembly including the header  40  (not shown in this figure) is fitted to the casing tube  88  which are hermetically sealed together as previously discussed with respect to  FIGS. 15 to 17 . The remaining steps in constructing the capacitor including introducing the electrolyte therein and hermetically sealing the capacitor proceed as previously described. 
   It is appreciated that various modifications to the inventive concepts described herein may be apparent to those of ordinary skill in the art without departing from the spirit and scope of the present invention as defined by the appended claims.