Electrode materials from hydrous metal and/or hydrous mixed metal oxides and method of preparing the same

• US 5,851,506 A
• Filed: 07/11/1996
• Issued: 12/22/1998
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Government Of The United States Of America , As Represented By The Seceretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Zheng, Jian-Ping, Jow, T. Richard
• Primary Examiner(s): Straub, Gary P.
• Assistant Examiner(s): Hendrickson, Stuart L.
• Application Number:
  US08/678,222
• Time in Patent Office: 894 Days
• Field of Search: 423/592, 423/593, 423/594, 423/598, 423/599, 502/326, 502/325, 502/300, 492/218, 252/182.1
• US Class Current: 423/592.1
• CPC Class Codes: C01B 13/145 After-treatment of oxides or hydroxides, e.g. pulverising, drying, decreasing the acidity
• CPC Class Codes: C01B 13/366 by hydrothermal processing
• CPC Class Codes: C01G 55/00 Compounds of ruthenium, rhodium, palladium, osmium, iridium, or platinum
• CPC Class Codes: C01G 55/004 Oxides; Hydroxides
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/88 by thermal analysis data, e.g. TGA, DTA, DSC
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: H01G 9/0425 specially adapted for cathode
• CPC Class Codes: H01M 4/48 of inorganic oxides or hydroxides
• CPC Class Codes: H01M 4/9016 Oxides, hydroxides or oxygenated metallic salts
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An electrode material comprised of hydrous metal oxide, such as ruthenium oxide, is annealed up to temperature just below the temperature at which the hydrous metal oxide would crystallize. Therefore, the hydrous metal oxide remains amorphous or non-crystalline. A hydrous metal oxide material treated in this manner provides a charge storage capacity and energy density greater than 747 F/g and 92 joules/gram, respectively, over 1 V range in a sulfuric acid electrolyte. This invention also provides a method of material preparation, wherein a sol-gel process is used to fabricate the hydrous metal oxides and wherein commercially available hydrous ruthenium oxide powders are treated and annealed.

Claims

1. An electrode material for electrochemical devices comprising amorphous, hydrous ruthenium oxide having the formula RuO₂.xH₂ O, where x is a water content value which is between 0.2 and 2.0, and a specific capacitance value greater than 500 Farads/gram.

2. The electrode material of claim 1 wherein said x water content value is between 0.2 and 1.8.