Facile Synthesis of Spike-Piece-Structured Ni(OH)₂ Interlayer Nanoplates on Nickel Foam as Advanced Pseudocapacitive Materials for Energy Storage

The spike-piece-structured Ni(OH)2 multilayer nanoplate arrays on nickel foams are directly synthesized by a facile hydrothermal method at 160 °C for 4 h. A possible mechanism for the growth of those nanostructures is proposed based on the experimental results. It is discovered that the surface of nickel foams could affect the orientation of the Ni(OH)2 nanoplates. This unique multilayer nanoplate array structure significantly enhances the electroactive surface areas of Ni(OH)2, leading to shorter ion-diffusion paths, and displays a capacity of 2.83 F/cm(2) at a current density of 6 mA/cm(2) in 0-0.48 V versus the saturated calomel electrode. It also exhibits a good cycling performance, with 51.5% of its initial capacity after about 3000 cycles at a large current density of 24 mA/cm(2). The present results may provide a new strategy for the synthesis and application of nickel-foam-based composites for energy storage.