Ultra- or supercapacitors are emerging as a key enabling energy storage technology for use in fuel-efficient transport as well as in renewable energy systems (for instance as power grid buffer). These devices combine the advantages of conventional capacitors, that can rapidly deliver high power densities on demand, and batteries, that can store a large amount of electrical energy.
"Among the various types of supercapacitors, carbon nanotube (CNT) based devices have shown an order of magnitude higher performance in terms of energy and power densities," says Ramakrishna Podila, an Assistant Professor in the Department of Physics and Astronomy at Clemson University. "The bottleneck for transferring this technology to the marketplace, however, is the lack of efficient and scalable manufacturing methods."
Podila's team at Clemson University have developed a new scalable method to directly spraycoat CNT-based supercapacitor electrodes. "Much like painting a car or a wall in your home, we can spray CNT solutions on flexible electrodes, porous aluminum foils in our case, to achieve high energy density supercapacitor electrodes without the need of any binder," explains Podila.
The resulting supercapacitors have a 10 times higher energy density compared to the state-of-the-art supercapacitors on the market.