Controlling Morphologies and Structures of PANI@Carbon with Superior Rate Performance for Supercapacitors

The preparation of porous carbon (PC) with a unique morphology, appropriate pore size distribution, and heteroatom doping has been a major challenge for high-performance supercapacitors. Herein, we developed nematosphere-like N-doped porous carbon (NNPC) via the activation of a polyaniline@PC (PANI@PC) composite that was acquired through PANI in situ growth on the surface of PC derived from Al-MOF (MOF, metal–organic framework). The as-prepared NNPC material possesses a huge specific surface area of up to 2360 m2 g–1 as well as a pore volume of 1.15 cm3 g–1, exhibiting an excellent specific capacitance (346 F g–1 at 1 A g–1) and amazing rate performance with 78.3% capacitance retention when the working current density swells from 1 to 100 A g–1. In addition, the electrode material also displays an extraordinary cyclic stability with an extremely low capacitance loss of 5.9% over 100 000 cycles at 50 A g–1. Furthermore, this NNPC-based symmetric supercapacitor delivers a superior energy density of 23.7 W h kg–1 in 6 M KOH with a 0–1.4 V operating voltage. These outstanding electrochemical performances are attributed to the nematosphere-like morphology, hierarchical pore structure, and enhanced electrical conductivity of NNPC for fast ion/charge migration and exchange. This work proposes a strategy to develop innovative electrode materials by combining MOF-derived PC and N-rich polymer for supercapacitor applications.