Ni nanoparticles embedded into cross-linked NiO nanoflakes as enhanced cathode for alkaline batteries

Construction of metal/metal oxide composite arrays is highly important for developing advanced electrochemical energy devices. In this work, we report a facile electrodeposition method to embed Ni network into hydrothermal NiO nanoflake arrays. Ni nanoparticles of 10-25 nm are intimately integrated with NiO nanoflakes of 20-30 nm forming cross-linked Ni/NiO composite arrays. The electrochemical potentials of Ni/NiO composite arrays are explored as cathode of alkaline batteries by means of galvanostatic charge/discharge tests and cyclic voltammograms (CV) in KOH solution. Compared with the unmodified NiO nanoflake arrays, the Ni/NiO composite arrays show much better electrochemical properties with higher capacity (100 mAh g(-1) vs. 75 mAh g(-1) at 2 A g(-1)), enhanced cycling life (capacity retention: 96% vs. 82%) after 3800 cycles and improved high-rate capability. The introduction of Ni nanoparticles not only improves the electrical conductivity, but also acts as anchors to fasten the active nanoflakes to achieve long-term cycles. (C) 2017 Elsevier Ltd. All rights reserved.