Construction of 3D star-shaped Co–NCs for high-performance supercapacitors

Zeolitic imidazolate frameworks (ZIFs) have greatly attracted attention in supercapacitors research due to their porosity and structural controllability. In this paper, a series of Co–nitrogen carbon (Co–NCs) were obtained via a facile one-step calcination process using 3D star-shaped Co–ZIF as a precursor. The energy storage mechanism is analyzed and it is concluded that Co–NCs show excellent capacitance and cycling stability, attributed to its star-shaped porous morphology and high pseudocapacitance contribution. The optimized Co–NCs/550 exhibits a specific capacity of 825 F g −1 at a current density of 0.1 A g −1 , and a highly stable cycling performance over 5000 cycles at a current density of 2 A g −1 . This work provides a practical strategy for designing stable electrode for high-performance supercapacitors.