The Drexel University nano-materials group together with a group of french researchers lead by Patrice Simon of Paul Sabatier university have recently published in Science a paper describing methods for thin film carbon supercapacitors into standard silicon based micro-circuitry. The carbon is deposited on top of a silicon substrate as a titanium carbide (TiC) film. After chlorination most of the TiC film is converted into a high surface areas porous carbon film which can be used to create a micro supercapacitor. The residual TiC act as a stress buffer with the underlying Si film. Regarded a energy storage devices supercapacitors have very high power density and very long cycle life (> 1 million). However, their energy density is more than an order of magnitude lower than lithium ion batteries.
The Drexel university announcement of these new ‘energy storage on a chip’ devices is quite enthusiastic about potential micro-electronics applications, but does not really describe the application space that is being targeted. I would be extremely surprised if the energy density is high enough to compete with lithium ion batteries, but there may be lower energy requirement applications that can use this technology. The article emphasizes the fact the the carbon films are flexible and can thus be integrated into flexible circuitry. Possibly wearable electronics is one the imagined applications for this new technology.