The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
Jun. 03, 1997
Jai Prakash, Gainesville, FL (US);
Michael M Thackeray, Naperville, IL (US);
Dennis W Dees, Downers Grove, IL (US);
Donald R Vissers, Naperville, IL (US);
Kevin M Myles, Downers Grove, IL (US);
Other;
Abstract
A pseudo-capacitor having a high energy storage capacity develops a double layer capacitance as well as a Faradaic or battery-like redox reaction, also referred to as pseudo-capacitance. The Faradaic reaction gives rise to a capacitance much greater than that of the typical ruthenate oxide ultracapacitor which develops only charge separation-based double layer capacitance. The capacitor employs a lead and/or bismuth/ruthenate and/or iridium system having the formula A.sub.2 �B.sub.2-x Pb.sub.x !O.sub.7-y, where A=Pb, Bi, and B=Ru, Ir, and O<x.ltoreq.1 and O<y<0.5 and limits the amount of ruthenate and/or iridium in the electrodes while increasing the energy storage capacity. The ruthenate can be synthesized at low temperatures (40.degree.-80.degree. C.) to form a compound with a high surface area and high electronic conductivity which, in combination with the increased pseudo-capacitance, affords high energy/power density in the pseudo-capacitor. The amount of expensive ruthenate and iridium can be substantially reduced in the pseudo-capacitor by increasing the lead content while improving energy storage capacity.