MOF-derived NiO nanoparticles prilled by controllable explosion of perchlorate ion: Excellent performances and practical applications in supercapacitors

Abstract

As an energy dot, the ClO4− ion is introduced into one nickel metal-organic framework (Ni-MOF), which appears as micron-scale lanterns. Then Ni-MOF is used as a precursor to prepare a series of NiO materials through a calcination-thermolysis procedure. The explosion behavior of ClO4− ion is exactly controlled by the heating rate, and the size of NiO particle is regularly reduced as increasing the heating rate. At 3 °C min−1, Ni-MOF micron lanterns are well prilled by the ClO4− ion into hierarchical cauliflower-like nanoparticles (NiO-3), which are composed of uniformly distributed superfine florets. Due to large specific surface area, supercapacitive properties of NiO-3 are initially studied by a three-electrode system, which shows a prominent capacitance of 1863 F g−1. Following, NiO-3 is integrated with activated carbon into an asymmetric supercapacitor cell (ASC), which exhibits notable energy density of 38.4 Wh kg−1 at power density of 400 W kg−1 and good long-term recycling (82% retension after 5000 cycles). Significantly, ASC is really applied in lighting, fanning and vehicle, and remarkable performances indicate NiO-3 is a suitable electrode candidate for supercapacitors.