SYNTHESIS AND CHARACTERIZATION OF CARBON-BASED NANOSTRUCTURES FOR NEXT GENERATION SUPERCAPACITORS

Abstract

TO ADDRESS THE INCREASINGLY SERIOUS ENVIRONMENTAL PROBLEMS AND EXCESSIVE CONSUMPTION OF FOSSIL FUELS, THERE HAS BEEN GREAT URGENCY IN EXPLOITING AND REFINING CLEAN ENERGY TECHNOLOGIES AS WELL AS MORE EFFICIENT ENERGY STORAGE DEVICES. AS ONE OF SUCH ENERGY STORAGE DEVICES, SUPERCAPACITORS, HAVE BEEN WIDELY STUDIED AROUND THE WORLD IN RECENT YEARS BECAUSE IT CAN OFFER ENERGY DENSITY BY ORDERS OF MAGNITUDE HIGHER THAN CONVENTIONAL CAPACITORS, LAGER POWER DENSITY AND BETTER CYCLING STABILITY THAN BATTERIES. HOWEVER, THE APPLICATION OF CURRENT COMMERCIALLY AVAILABLE SUPERCAPACITORS IS STRONGLY INHIBITED DUE TO THEIR RELATIVELY LOW ENERGY DENSITY (~10 WH/KG) AS COMPARED TO THAT OF BATTERIES (~100 WH/KG). ACCORDING TO THE EQUATIONS OF ENERGY DENSITY (E): E=1/2?CV2 AND POWER DENSITY (P): P=V2/4RS FOR SUPERCAPACITORS (WHERE C IS THE TOTAL CAPACITANCE OF THE CELL, V IS THE CELL VOLTAGE, RS IS THE EQUIVALENT SERIES RESISTANCE), THE ENERGY DENSITY IS MAINLY DEPENDENT ON CELL OPERATION VOLTAGE AND