Hierarchically Porous and Orderly Mesostructured Carbon Nanorods with Excellent Supercapacitive Performance

Ordered mesoporous carbon (OMC), as a supercapacitor electrode material, can reduce ion diffusion resistance and facilitate rapid mass transfer. Since the nanopore structure in the porous carbon electrode can act as a buffer reservoir for electrolyte ions, incorporating nanopores into OMC can minimize the diffusion distance of electrolyte ions at high current densities, thereby improving their performance in supercapacitor applications. Herein, hierarchical porous carbon nanorods with ordered mesoporous structures (OMRCs) were fabricated through a polyacrylic acid/hexadecyl trimethyl ammonium bromide complex template self-assembly strategy. The prepared OMRCs had a unique Fm3m mesostructure with the primary ordered mesopores (∼3.6 nm) and secondary nanopores (∼16 nm), the nanopores are randomly distributed in the carbon matrix without disrupting the ordered mesoporous structure. Benefiting from the unique pore structure of OMRCs, large specific surface area (737 m2 g–1), and pore volume (0.93 cm3 g–1), the OMRCs electrode performed a high specific capacitance of 442 F g–1 at 1 A g–1and an outstanding rate capability in the application of supercapacitors. Moreover, a symmetric supercapacitor was assembled with OMRC electrodes in a two-electrode system. At a power density of 250 W kg–1, the supercapacitor displayed a high energy density of 15.5 Wh kg–1. After 10,000 cycles at 2 A g–1, the supercapacitor exhibited 1.5% capacitance fading. The remarkable electrochemical performance of OMRCs makes them suitable electrode materials for high-performance supercapacitors.