Electroless Deposition of Conformed Nanoscale Iron Oxide on Carbon Nanoarchitectures for Electrochemical Charge Storage

Journal Article · Fri Jan 01 00:00:00 EST 2010 · ACS Nano

DOI:https://doi.org/10.1021/nn100572a· OSTI ID:1020159

Sassin, M; Mansour, A; Pettigrew, K; Rolison, D; Long, J

We describe a simple self-limiting electroless deposition process whereby conformal, nanoscale iron oxide (FeO{sub x}) coatings are generated at the interior and exterior surfaces of macroscopically thick ({approx}90 {micro}m) carbon nanofoam paper substrates via redox reaction with aqueous K{sub 2}FeO{sub 4}. The resulting FeO{sub x}-carbon nanofoams are characterized as device-ready electrode structures for aqueous electrochemical capacitors and they demonstrate a 3-to-7 fold increase in charge-storage capacity relative to the native carbon nanofoam when cycled in a mild aqueous electrolyte (2.5 M Li{sub 2}SO{sub 4}), yielding mass-, volume-, and footprint-normalized capacitances of 84 F g{sup -1}, 121 F cm{sup -3}, and 0.85 F cm{sup -2}, respectively, even at modest FeO{sub x} loadings (27 wt %). The additional charge-storage capacity arises from faradaic pseudocapacitance of the FeO{sub x} coating, delivering specific capacitance >300 F g{sup -1} normalized to the content of FeO{sub x} as FeOOH, as verified by electrochemical measurements and in situ X-ray absorption spectroscopy. The additional capacitance is electrochemically addressable within tens of seconds, a time scale of relevance for high-rate electrochemical charge storage. We also demonstrate that the addition of borate to buffer the Li{sub 2}SO{sub 4} electrolyte effectively suppresses the electrochemical dissolution of the FeO{sub x} coating, resulting in <20% capacitance fade over 1000 consecutive cycles.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
• Sponsoring Organization: DOE - OFFICE OF SCIENCE
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 1020159
• Report Number(s): BNL-96009-2011-JA; TRN: US201116%%139
• Journal Information: ACS Nano, Vol. 4, Issue 8; ISSN 1936-0851
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
BORATES
BUFFERS
CAPACITANCE
CAPACITORS
CAPACITY
CARBON
COATINGS
DEPOSITION
DISSOLUTION
ELECTRODES
ELECTROLYTES
IRON OXIDES
REDOX REACTIONS
STORAGE
SUBSTRATES
national synchrotron light source