Al-MOF-derived spindle-like hierarchical porous activated carbon for advanced supercapacitors

Abstract

Metal organic frameworks (MOFs) and their derivatives have been widely used in electrochemistry due to their adjustable pore size and high specific surface area (SSA). Herein, a spindle-like hierarchical porous activated carbon (SPC) was synthesized through carbonizing the Al-BTEC precursor and then alkaline washing with NaOH. The fabricated SPC has a uniform shuttle-shaped structure, showing a large BET surface area of 1895 m² g⁻¹ and an average pore size of 2.4 nm. The SPC product displays a high specific capacitance (SC) of 337 F g⁻¹ at 1 mV s⁻¹ and 334 F g⁻¹ at 1 A g⁻¹. The retention of SC is about 95% after 100 000 cycles when the current density is 50 A g⁻¹, indicating its excellent stability. Furthermore, the assembled symmetrical capacitor with a two-electrode system exhibits a high SC of 173 F g⁻¹ at 1 A g⁻¹ and an energy density of 15.3 W h kg⁻¹ at a power density of 336 W kg⁻¹. This work would provide a new pathway to design and synthesize carbon materials for supercapacitors with excellent properties in the future.