Indian cake rusk helps make supercapacitors
doi:10.1038/nindia.2018.114 Published online 29 August 2018
Researchers have synthesised nanoporous activated carbon from food waste derived from Indian cake rusk1. The carbon, when used as electrodes in supercapacitors, display remarkable efficiency in storing charge, making them potentially useful for making energy storage devices.
Supercapacitors are widely used in power back-up systems, memory devices and other electronic devices that can produce electricity on demand. However, existing techniques for making supercapacitors are expensive and time consuming.
In search of a simple technique, scientists from SRM Institute of Science and Technology in Tamil Nadu, India, prepared nanoporous activated carbon from waste Indian cake rusk obtained from bakeries. They then converted the carbon into electrodes that were used for making supercapacitors.
Since the carbon has a high surface area, with nanopores and macropores, the carbon-based electrodes enabled the supercapacitors to display a high charge storage capacity. Besides storing charge, the network of pores on the carbon surface facilitated fast ion transport, enhancing conductivity and generating high current density.
The carbon electrodes’ efficiency in storing charge was higher than those of other carbon materials such as graphite, graphene and single-walled carbon nanotubes. They also exhibited a current density that is 10 times as high as that of an electrode made of unactivated carbon.
The carbon electrodes retained their efficiency in storing charge even after 6000 cycles of charging and discharging. The researchers say that the nanoporous carbon could serve as a promising carbon material for advanced applications in the energy, environmental and biomedical fields.