NEST - Nanowires for Energy STorage
Among today challenges that of energy needs is one of the most important. An obvious question is its production but the need of energy storage systems is almost as large. Renewable energies will not have an impact unless we find an efficient way to store the electricity that they produce. Energy should be available everywhere and at any time, this translates in a strong need for energy containers in the form of electrochemical storage.
Batteries have been in everyone’s pocket for a long time (camera, mobile phone,..). Lithium ion batteries have aided the portable electronics revolution during the past two decades because they exceed at least by a factor of 2.5 any competing technology thanks to their high value of energy density, i.e. 150 Whkg-1 and 650 WhL-1. On the other hand dielectric capacitors are the one to provide energy when peak power is required. Between these two extremes (Li-ion batteries and dielectric capacitors), supercapacitors, SCs, (also called ultracapacitors or electrochemical capacitors, ECs) fill in the energy and power gaps.
For storing usable amounts of energy SCs are poised to challenge batteries in a growing range of applications. In hybrid electrical vehicles, for instance, supercapacitors have demonstrated a higher braking energy recovery than batteries; they are considerably lighter and have a longer economic life. Ultracapacitors provide also burst power for lifting, acceleration, emergency (e.g. door opening of the Airbus A380, Maxwell Company) and are presently used in forklifts, seaport cranes and hybrid city transit buses.