Hierarchically Porous Carbon from Phoenix dactylifera Seed for High-Performance Supercapacitor Applications

Large surface area hierarchically nanoporous activated carbons are prepared by KOH activation and high temperature carbonization of agricultural waste, Phoenix dactylifera (date) seeds. The nanoporous activated carbon obtained by this method has excellent surface porosity with very large surface area, typically 2383.2m(2) g(-1), and large pore volume (1.76 cm(3) g(-1)) due to their interconnected micro- and mesoporous structure. The hierarchically nanoporous material of this activated carbon leads to excellent electrochemical charge storage capability for their application as supercapacitor electrode materials. In a three-electrode cell, an optimum carbon sample exhibited high specific capacitance ca. 386 F g(-1) at a current density of 1Ag(-1) with excellent retention of specific capacitance (63%) at a very high current density of 50Ag(-1). Cyclic stability is also excellent with 98% specific capacitance retention after 10,000 charge-discharge cycles. These hierarchical nanoporous activated carbons derived from agricultural waste materials have sufficient potential for use as electrode materials in commercial, and advanced supercapacitors.