Researchers devise method to develop eco-friendly supercapacitors using activated carbon produced from coconut husks

The researchers of the Government College for Women, Thiruvananthapuram, have devised a method to produce activated carbon, suitable for supercapacitor fabrication, from coconut husks, a major agricultural residue in Kerala.

The coconut husk biowaste-derived activated carbon holds immense promise for sustainable and efficient green solutions for high-performance supercapacitors due to its availability, low cost, and eco-friendly nature.

Vital component

Supercapacitors, with significantly higher capacitance and energy storage capacity than conventional capacitors, have emerged as a vital component in the quest for sustainable energy storage solutions. But, the search for an ideal supercapacitor electrode material has been a significant challenge.

The research team, led by Xavier T.S., Assistant Professor, Department of Physics and including Merin Tomy, Ganesh S.G., Anu M.A., and Sreelakshmi S.R., found the prototype supercapacitors made of coconut husk-derived activated carbon to be four-times more efficient that the existing supercapacitors.

The findings have been published in American Chemical Society’s peer-reviewed Sustainable Resource Management Journal.

The team had leveraged the innovative microwave-assisted method designed at the Centralised Common Instrumentation Facility (CCIF) at the college.

‘Inexpensive’

According to Dr. Xavier, activated carbon produced in this manner, utilising microwave technology, is relatively inexpensive and exhibits exceptional supercapacitor capability. The innovative microwave-assisted method has also opened new avenues for the production of activated carbon, which is under consideration for an Indian patent.

By utilising an advanced microwave pyrolysis reactor, the team was able to produce high-quality carbon within five minutes, eliminating impurities like ash and generating zero waste.

This innovative method not only saves time, but also yields activated carbon with an impressive surface area of 1,200 m² g^-1 and highly porous structures, making it an ideal material for various applications. The device’s high-power output is capable of powering two LEDs for 20 minutes, the researchers said.

CCIF, funded by the State government, is equipped with world-class state-of-the-art facilities, including advanced instruments like Nuclear Magnetic Resonance (NMR) spectrometer, Brunauer-Emmett-Teller (BET) analyser, fluorometer, electrochemical workstation, and PCR machines. The facility has already catered to the needs of researchers from over 50 colleges, six universities, and six national institutes.