Nitrogen-enriched porous carbon nanorods templated by cellulose nanocrystals as high performance supercapacitor electrodes

Abstract

Cellulose nanocrystals (CNCs) for the very first time were converted into highly porous nitrogen (N)-doped carbon nanorods that display promising capacitive performance as electrode materials for supercapacitors. CNCs were used as both a carbon source and a template for the controlled-growth of the N precursor to form melamine-formaldehyde (MF) coated CNC nanorods (MFCNCs). The resulting hybrid material was further subjected to a one-step pyrolysis to yield N-doped carbon nanorods (N-MFCNCs) of high N doping content and favourable micro-, meso-, and macropores. An optimal capacitance of 328.5 F g⁻¹ from the CV test at 0.01 V s⁻¹ and 352 F g⁻¹ from the CD test at 5 A g⁻¹ was achieved for N-MFCNCs in sulfuric acidic electrolyte (1 M). The material also exhibits high cycling stability (less than 4.6% loss after 2000 cycles) at a high current density of 20 A g⁻¹. The versatility of the material was further demonstrated by high capacitive performance in neutral and alkaline electrolytes. Our work offers a promising alternative approach to fabricate high-performance nanostructured carbon from abundant biomass via facile and low-cost processing for energy storage applications.