One-pot construction of highly oriented Co-MOF nanoneedle arrays on Co foam for high-performance supercapacitor.

Highly oriented Co-MOF nanoneedle arrays areconstructed on Co foam (Co-MOF@Co) by using a one-pot solvothermal strategy. As-prepared Co-MOF@Co can be directly served as a binder-free electrode for supercapacitor, which exhibits wonderful electrochemical performances, i.e. high specific capacitance (12783.0 mF cmor 1164.2 F g), exceptional cycling stability (90.5% retention over 10 000 cycles at 250 mA cm) with a loading of 10.98 mg cm. Meanwhile, an asymmetric supercapacitor of AC//Co-MOF@Co delivers a high ratability (87% retention upon ten-fold current density) and high energy density of 43.4 W h kgat the power density of 145.1 W kg.