Self-Templating Synthesis of 3D Hollow Tubular Porous Carbon Derived from Straw Cellulose Waste with Excellent Performance for Supercapacitors

A three-dimensional hollow tubular porous carbon (SCPC) was prepared from straw cellulose waste through a self-templating method combined with NaOH activation. Straw cellulose acts both as carbon source and structural template. The obtained SCPC exhibits a 3D hierarchical porous network structure. SCPC has a high specific surface area, a high mesoporosity ratio, and a low resistivity, which make it display excellent electrochemical performance for supercapacitors. SCPC showed a high specific capacitance of 312.57Fg(-1) in 6m KOH at 0.5Ag(-1), an excellent rate performance of 281.32Fg(-1) even at 15Ag(-1), and an outstanding cyclic stability of 92.93% capacitance retention after 20000cycles at 1Ag(-1). SCPC-based supercapacitors can deliver an energy density of 8.67Whkg(-1) at a power density of 3.50kWkg(-1) in 6m KOH and an energy density of 28.56Whkg(-1) at a power density of 14.09kWkg(-1) in 1m Et4NBF4/PC, which demonstrates the possibility of applying SCPC in supercapacitors. This research not only offers a facile and sustainable method for the preparation of hierarchical porous carbon for electrochemical energy storage devices but also provides a highly efficient method for the utilization of biomass waste.