Self-supported Ni decorated NiO nanoflake arrays as promising cathode materials of hybrid batteries

In this work, self-supported Ni decorated NiO nanoflake arrays are synthesized by using chemical bath deposition and magnetron sputtering methods. The NiO nanoflakes have diameters of 10-15 nm and are cross-linked to form a porous net-like structure with pore diameters ranging from 50 to 350 nm. After Ni sputtering, the NiO nanoflakes are well coated by the Ni particles forming a porous Ni@NiO composite arrays structure. As cathode of hybrid batteries, the Ni@NiO composite arrays exhibit better electrochemical performance with higher capacity (55.6 mAh g(-1) at 1.5 Ag-1) than the pure NiO nanoflake sample (29.5 mAh g(-1)). Moreover, the Ni@NiO composite electrode is demonstrated with superior cycling stability with 93% capacity retention after 8000 cycles. The introduction of Ni layer is responsible for the improvement of electrochemical properties due to good structural stability and better electrical path. (C) 2015 Elsevier Ltd. All rights reserved.