Graphene-anchored NiCoO2 nanoarrays as supercapacitor electrode for enhanced electrochemical performance.

Porous flower-like NiCoO 2 and graphene (NiCoO 2 /rGO) composite nanoarrays were grown directly on Ni foam (NF) without any binders by a simple hydrothermal synthesis method. Due to the porous flowers-like architecture of ultrathin NiCoO 2 nanoflakes and the introduction of graphene with the high electrical conductivity, NiCoO 2 /rGO composite nanoarrays showed superior electrochemical performance including high specific capacity (1286C g −1 at 0.5 A g −1 ), and good rate capability (1071.5C g −1 , 83.3% capacity retention at 12 A g −1 ). The asymmetric supercapacitor assembled with NiCoO 2 /rGO and rGO/NF also showed good performance with the energy density of 38.5 Wh kg −1 at 288 W kg −1 power density and good cycle stability of 86.9% after 2000 cycles. These results demonstrate the potential application of NiCoO 2 /rGO composite nanoarrays as a promising electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]