Easy approach to synthesize N/P/K co-doped porous carbon microfibers from cane molasses as a high performance supercapacitor electrode material

Abstract

In this study, we demonstrate a simple and low cost method to synthesize N/P/K co-doped porous carbon microfibers (CMFs) from a sugar-rich byproduct (cane molasses) as the precursor material. A two-step method for the synthesis of N/P/K co-doped porous CMFs involving electrospinning of precursor material followed by simple carbonization at various temperatures (773.15-1173.15 K) was successfully applied. The N/P/K co-doped porous CMFs exhibited high specific surface area (∼580 m2 g-1) and hierarchical porous structure. The potential application of N/P/K co-doped porous CMFs as supercapacitor electrodes was investigated in a two-electrode configuration employing aqueous K2SO4 solution and ionic liquids/acetonitrile (ILs/ACN) mixtures as the electrolytes. A series of electrochemical measurements include cyclic voltammetry, galvanostatic charge-discharge and cycling durability all confirmed that the CMF-1073.15 supercapacitor exhibited good electrochemical performance with a specific capacitance of 171.8 F g-1 at a current load of 1 A g-1 measured in 1.5 M tetraethylammonium tetrafluoroborate (TEABF4)/ACN electrolyte, which can be charged and discharged up to a cell potential of 3.0 V. The specific energy density and power density of 53.7 W h kg-1 and 0.84 kW kg-1 were achieved. Furthermore, the CMF-1073.15 supercapacitor showed excellent cycling performance with capacitance retention of nearly 91% after 2500 charge-discharge cycles, characterizing its electrochemical robustness and stable capacitive performance. © 2014 the Partner Organisations.