In the framework of an ERC proof-of-concept European Project, Magnetic Supercapacitors, new hybrid materials for energy storage based on graphene and magnetic nanoparticles, have been developed.
The rapid increase in energy demand in recent years has accelerated the search for low-cost alternatives for energy storage and conversion. Currently, batteries are still considered as the dominating energy storage devices, but they have a low power density and lose their ability to retain energy throughout their lifetime due to material damage.
Supercapacitors store the energy electrostatically on the surface of the material. They are able to store high amounts of energy and can release them very quickly when needed, leading to a very high power density. Furthermore, they have the ability to repeat many charge-discharge cycles without losing efficiency, as chemical reactions are not involved in the process. While batteries can supply energy in a sustained release, supercapacitors can deliver high power bursts so they perfectly fit the current market needs (recovery of energy derived from braking (trains, tramways), source of energy for the starting of electric motors…).
The magnetic supercapacitors developed at ICMol are formed by a graphene based nanocomposite together with FeNi3 nanoparticles. These supercapacitors show a huge increase of their features after being subjected to a series of galvanostaic cycles in the presence of a magnetic field, improving the characteristics of the original material, from a capacitance of 100 Fg-1 to 1000 Fg-1, which is, altogether superior if compared to current commercial materials. These properties make them attractive for the industry, having caught already the attention of several companies in the energy sector.
This discovery has led to three patents and, at this moment, ICMol is carrying further developments in this field addressed to integrate the electroactive material in the so-called Systems in a Chip (SoCs). The integration of ultra-small, flexible and compact components that act on the chip as energy storage units is a key factor to the power autonomy of remote sensors, small robots, medical devices or wearable devices. This involves the replacement of their traditional design with new architectures and processes. Particular attention will have to be paid to energy and economic costs, and to the possibility for automation and reuse of the materials. This innovative concept will contribute as well to the boost of the industrial use of SoCs.
Cicret Wearable Projection Band image in the public domain, taken from Flickr, authored by Yagisu.