Electrochemical fabrication and characterization of hierarchically porous supercapacitors

COLL 487

David B. Robinson, drobins@sandia.gov1, Weon-Sik Chae, wschae@uiuc.edu2, Paul V. Braun, pbraun@uiuc.edu2, and Blake A Simmons, basimmo@sandia.gov3. (1) Energy Systems Dept, Sandia National Laboratories, PO Box 969 MS 9291, Livermore, CA 94551-0969, (2) Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, (3) Deconstruction Division, Joint BioEnergy Institute, Emeryville, CA 94608
Nanoscale porosity in supercapacitors provides very high surface areas in a given volume, allowing for storage of large amounts of electrical energy. However, transport through such narrow pores into the middle of a macroscopic device is very slow. To overcome this, a network of larger-scale, low-resistance pores is necessary that requires minimal sacrifice of the finer storage material. We present a method to demonstrate this using dealloyed gold that was electroplated into an inverse opal template, resulting in length scales of millimeters (device area), microns (film thickness), hundreds of nanometers (opal periodicity) and tens of nanometers (gold porosity). Adjustment of gold surface chemistry allows interfacial capacitance and surface energy to be tuned, aiding characterization of these complex structures, and also allows incorporation of pseudocapacitive components. This work provides a toolbox that will aid development of sophisticated nanoscale architectures for electrical energy storage devices.

 

Electrochemistry-Enabled Nano S&T
2:00 PM-5:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 229, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008