Superior asymmetric supercapacitor based on Ni-Co oxide nanosheets and carbon nanorods

摘要

Nickel and cobalt (Ni-Co) binary oxide nanosheets with mesoporous structure are prepared by a facile approach based on the formation and disassociation of nickel/cobalt-citrate complex, and they show an ultra-high Faradaic capacitance up to 1846?F g?1 and excellent rate capability. On this basic, advanced aqueous asymmetric supercapacitors (AASs) are successfully built by using the Ni-Co oxide as the positive electrode and three kinds of activated carbons respectively as the negative electrode. As-made AASs are able to work reversibly in a full operated voltage region of 0–1.6?V and exhibit outstanding electrochemical performance. Among them, activated polyaniline-derived carbon (APDC)//Ni-Co oxide AASs shows the highest specific capacitance of 202?F g?1, the maximum energy density of 71.7?Wh kg?1, and superior combination of high energy and power density (a energy density of 41.6?Wh kg?1 at a high power density of 16?kW kg?1).