MOF-derived conformal Cobalt Oxide/C composite material as high-performance electrode in hybrid supercapacitors

Abstract By pyrolysis of a simple Cobalt Metal Organic Framework (MOF) we have been able to synthesize a high-performance hybrid composite electrode with fibrous morphology conformal to the MOF, in a single step and at relatively low temperature (700°C). Indeed, the composite material containing cobalt oxide micro-nano-particles in highly graphitized carbon matrix (cobalt oxide/C-700) presents superb capacity of 1372 F/g (381 mAh/g) at a current density of 2.5 A/g. Besides, an asymmetric supercapacitor (ASC) was fabricated by using the CoxOy/C-700 composite as positive electrode and activated carbon (AC) as negative electrode. This ASC system delivered maximum energy density of 51.5 Wh/kg and maximum power density of 1687 W/kg