Fabrication of flexible ultracapacitor/galvanic cell hybrids using advanced nanoparticle coating technology

Ultracapacitors represent an essential storage element in a variety of hybrid energy sources, ranging from automobile power systems to low-power motes in a distributed sensor network. Hydrated ruthenium (IV) oxide has demonstrated superior performance in terms of energy storage density (over 25 W h kg(-1)) as compared to other material systems. The cost of the oxide has been, however, a major impediment to the widespread use of this technology. In this article, the authors report on the fabrication of ruthenium (IV) oxide based ultracapacitor/galvanic cell hybrids made with a coating system capable of providing continuous, densely packed (but porous) layers of the nanoparticles with the thickness of one single nanoparticle. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3524906]