Hierarchically Porous\nand Orderly Mesostructured Carbon\nNanorods with Excellent Supercapacitive Performance

Abstract

Ordered mesoporous carbon (OMC), as a supercapacitor\nelectrode\nmaterial, can reduce ion diffusion resistance and facilitate rapid\nmass transfer. Since the nanopore structure in the porous carbon electrode\ncan act as a buffer reservoir for electrolyte ions, incorporating\nnanopores into OMC can minimize the diffusion distance of electrolyte\nions at high current densities, thereby improving their performance\nin supercapacitor applications. Herein, hierarchical porous carbon\nnanorods with ordered mesoporous structures (OMRCs) were fabricated\nthrough a polyacrylic acid/hexadecyl trimethyl ammonium bromide complex\ntemplate self-assembly strategy. The prepared OMRCs had a unique <i>Fm</i>3<i>m</i> mesostructure with the primary ordered\nmesopores (∼3.6 nm) and secondary nanopores (∼16 nm),\nthe nanopores are randomly distributed in the carbon matrix without\ndisrupting the ordered mesoporous structure. Benefiting from the unique\npore 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\nof 442 F g^–1 at 1 A g^–1and an\noutstanding rate capability in the application of supercapacitors.\nMoreover, a symmetric supercapacitor was assembled with OMRC electrodes\nin 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\nelectrochemical performance of OMRCs makes them suitable electrode\nmaterials for high-performance supercapacitors.