Energy dense electrolytic capacitor
View Patent ↗An electrical energy storage device such as a wet tantalum electrolytic capacitor or an electrochemical cell such as a lithium/silver vanadium oxide cell is described. The enclosure comprises a drawn casing portion having a planar face wall supporting a surrounding sidewall and is shaped to nest the anode, cathode and intermediate separator components. A mating cover is a stamped planar piece of similar material having a periphery edge welded to the edge of the casing portion surrounding sidewall. In order to prevent heat generated during the welding process from damaging the separator, the anode portion adjacent to the weld site is contoured. This provides sufficient space between the weld and the separator supported on the anode at the contour so that what heat is transmitted to the separator by convection and conduction mechanism will not damage the separator.
1. An electrical energy storage device, which comprises:
a) an enclosure comprising a casing portion comprising a casing face wall supporting a surrounding sidewall extending to a first peripheral edge, and a cover comprising a cover outer surface spaced from a cover inner face wall by a second peripheral edge, wherein the casing portion is closed by the cover with the first peripheral edge secured to the second peripheral edge;
b) a first active material in electrical contact with at least one of the casing face wall and the cover inner face wall;
c) a second active material as a shaped body of an opposite polarity as the first active material, wherein the shaped body comprises spaced apart first and second body face walls joined by an intermediate body end wall and wherein a first portion of the body end wall adjacent to the casing face wall is substantially normal to a plane of the first body face wall with a second portion of the body end wall meeting the second body face wall being inwardly contoured adjacent to where the first peripheral edge of the casing portion is secured to the second peripheral edge of the cover;
d) a separator intermediate the first and second active materials;
e) a glass-to-metal seal supported in at least one of the casing portion and the cover to electrically insulate a lead for the second active material from the enclosure serving as a terminal for the first active material; and
f) a working electrolyte provided in the enclosure in contact with the first and second active materials.
2. The electrical energy storage device of claim 1 wherein the first body face wall is of a greater area than the second body face wall.
3. The electrical energy storage device of claim 1 wherein the first portion of the body end wall extends from the first body face wall past a plane bisecting the width of the end wall between the first and second body face walls.
4. The electrical energy storage device of claim 1 wherein the first active material is a cathode active material contacted to the casing face wall and the cover inner wall by either a pad printing process or as an ultrasonically deposited spray.
5. The electrical energy storage device of claim 1 wherein either a polymeric cradle or a plurality of polymeric restraints support between the surrounding sidewall of the casing portion and the body end wall to prevent movement of the body of the second active material inside the enclosure.
6. The electrical energy storage device of claim 1 wherein the casing portion is welded to the cover at the respective first and second peripheral edges to provide the enclosure.
7. The electrical energy storage device of claim 1 wherein the first active material is a cathode active material 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 and the second active material is an anode selected from the group consisting of tantalum, aluminum, titanium, niobium, zirconium, hafnium, tungsten, molybdenum, vanadium, silicon, germanium, and mixtures thereof.
8. The electrical energy storage device of claim 1 as either a capacitor or an electrochemical cell.
9. An electrical energy storage device, which comprises:
a) an enclosure comprising a casing portion comprising a casing face wall supporting a surrounding sidewall extending to a first peripheral edge, and a cover comprising a cover outer surface spaced from a cover inner face wall by a second peripheral edge, wherein the casing portion is closed by the cover with the first peripheral edge secured to the second peripheral edge;
b) a cathode of a cathode active material in electrical contact with at least one of the casing face wall and the cover inner face wall;
c) an anode as a shaped body of anode active material, wherein the anode body comprises spaced apart first and second anode face walls joined by an intermediate anode end wall and wherein a first portion of the anode end wall adjacent to the casing face wall is substantially normal to a plane of the first anode face wall with a second portion of the anode end wall meeting the second anode face wall being inwardly contoured adjacent to where the first peripheral edge of the casing portion is secured to the second peripheral edge of the cover;
d) a separator intermediate the anode and cathode;
e) a glass-to-metal seal supported in at least one of the casing portion and the cover to electrically insulate a lead for the anode from the enclosure serving as a terminal for the cathode; and
f) a working electrolyte provided in the enclosure in contact with the anode and cathode.
10. The electrical energy storage device of claim 9 wherein the cover outer surface is planar.
11. The electrical energy storage device of claim 9 wherein the second portion of the anode end wall is planar and meets the second anode face wall at an obtuse angle.
12. The electrical energy storage device of claim 9 wherein the second portion of the anode end wall is substantially planar where it meets the first portion of the anode end wall and curved where it meets the second anode face wall.
13. The electrical energy storage device of claim 9 wherein the second portion of the anode end wall is concave.
14. The electrical energy storage device of claim 9 wherein the second portion of the anode end wall has an inwardly extending step shape.
15. The electrical energy storage device of claim 9 wherein there is an O-ring provided between the inwardly extending contour of the second portion of the anode end wall and where the first peripheral edge of the casing portion is secured to the second peripheral edge of the cover.
16. The electrical energy storage device of claim 15 wherein the O-ring is of a polymeric material having a cross-section selected from the group consisting of circular, rectangular, and square.
17. The electrical energy storage device of claim 15 wherein the polymeric material is selected from the group consisting of a polyimide, a silicone, PTFE, TFE, and polytrifluoroethylene.
18. The electrical energy storage device of claim 9 wherein the second peripheral edge of the cover extends beyond an outer surface of the surrounding sidewall of the casing portion.
19. The electrical energy storage device of claim 9 wherein the surrounding sidewall of the casing portion adjacent to the first peripheral edge is an outwardly turned lip having the first peripheral edge being coplanar with the second peripheral edge of the cover.
20. The electrical energy storage device of claim 9 wherein the second peripheral edge of the cover fits into the step at the first peripheral edge of the casing portion sidewall.
21. The electrical energy storage device of claim 9 wherein the casing enclosure is symmetrical along a bisecting plane.
22. An electrical energy storage device, which comprises:
a) an enclosure comprising a casing portion comprising a surrounding sidewall extending to a first peripheral edge, and a cover comprising a cover outer surface spaced from a cover inner face wall by a second peripheral edge, wherein the casing portion is closed by the cover with the first peripheral edge secured to the second peripheral edge;
b) a cathode of a cathode active material in electrical contact with at least one of the casing face wall and the cover inner face wall;
c) an anode as a shaped body of anode active material, wherein the anode body comprises a cylindrically shaped sidewall extending between opposed end walls and wherein a portion of the anode sidewall is inwardly contoured adjacent to where the first peripheral edge of the casing portion is secured to the second peripheral edge of the cover;
d) a separator intermediate the anode and cathode;
e) a glass-to-metal seal supported in at least one of the casing portion and the cover to electrically insulate a lead for the anode from the enclosure serving as a terminal for the cathode; and
f) a working electrolyte provided in the enclosure in contact with the anode and cathode.
23. The electrical energy storage device of claim 22 wherein the casing is symmetrical about a longitudinal axis.
24. A method for providing an electrical energy storage device, comprising the steps of:
a) providing casing portion comprising a casing face wall supporting a surrounding sidewall extending to a first peripheral edge, and a cover comprising a cover outer surface spaced from a cover inner face wall by a second peripheral edge;
b) electrically contacting a cathode active material to at least one of the casing face wall and the cover inner face wall to provide a cathode;
c) providing a shaped body of anode active material comprising spaced apart first and second anode face walls joined by an intermediate anode end wall;
d) enveloping the anode in a separator;
e) nesting the separator enveloped anode in the casing portion with the first anode face wall positioned adjacent to the casing face wall and with a glass-to-metal seal connected to a lead for the anode being supported in the surrounding sidewall of the casing portion to electrically insulate the lead there from;
f) closing the casing portion with its second peripheral edge being secured to the first peripheral edge of the casing portion to thereby enclose the anode and cathode therein, and providing a first portion of the anode end wall adjacent to the casing face wall being substantially normal to a plane of the first anode face wall with a second portion of the anode end wall meeting the second anode face wall being inwardly contoured adjacent to where the first peripheral edge of the casing portion is secured to the second peripheral edge of the cover; and
g) providing a working electrolyte in the enclosure in contact with the anode and the cathode.