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Graphical abstract The super-ionic conductivity nanowire Cu 2 Se/Ni-foam electrode processes excellent cycling performance and the electrode is firstly assembled to asymmetric supercapacitor achieving high energy and power density. Abstract Transition metal selenide has stimulated much research interest in energy storage and conversion, due to its excellent electrical conductivity. β-Cu 2 Se with special crystal structure is considered as super-ionic conductor, of which the diffusion coefficient is as large as a liquid. The fast ions and electrons conductor β-Cu 2 Se with uniformly dense nanowire crossing with each other directly on nickel foam is prepared via simple one-step solvothermal grow method for 4 h, avoiding conductive agent and binder. The feature much benefitting for electrons and ions transfer enable the β-Cu 2 Se-4h electrode delivers specific capacity as high as 182.4 mA h g−1 at current density of 2 mA cm−2, which is still 105.6 mA h g−1 even at high current density of 50 mA cm−2, and excellent cycling stability of 85% after repetitively charge-discharge 10,000 times. The fabricated asymmetric supercapacitor (β-Cu 2 Se-4h//AC) achieves maximum energy and power density is 48 Wh kg−1 and 5500 W kg−1. [ABSTRACT FROM AUTHOR]

A current collector of reduced graphene oxide modified Ni foam (RN) is synthesized through a handy method of hydrothermal. The sheet-like reduced graphene oxide (rGO) wrapped around the skeleton of Ni foam establishes a unique structure of the current collector with large surface area as well as good electronic conductivity which make a positive effect on the promotion of electrochemical property. Pd is chosen as the catalyst and deposited on the RN substrate in a form of nanoparticle by potentiostatic electro-deposition. Characterization analysis including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and inductive coupled plasma emission spectrometer (ICP) are conducted to investigate the morphology and structure of the final electrode of Pd nanoparticles decorated rGO supported on Ni foam (PRN). In 2 mol L −1 NaOH and 0.5 mol L −1 H 2 O 2 , a current density of 450 mA cm −2 is gained on the PRN electrode which is much larger than that on the electrode of Pd nanoparticles directly deposited on Ni foam (PN). An excellent stability of the PRN electrode is also concluded by the measurements revealing that this material can be potentially and widely applied to direct hydrogen peroxide fuel cell in the near future. [ABSTRACT FROM AUTHOR]

Novel Au@Ni nanoarrays electrode is facilely obtained by firstly template-assisted electro-deposition of Ni nanowire arrays (NAs), followed by galvanostatic deposition of Au catalysts onto the Ni NAs without any conductive agents and binders. The Au@Ni NAs electrode shows a rough surface and fringe with the diameter of ∼90 nm, which assures a high utilization of Au catalysts and provides a large specific surface area. The elemental distribution of Ni mainly exists in the inner layer of a single Au@Ni nanowire with the diameter ∼56 nm, while the elemental distribution of Au catalysts merely appears in the outer layer to form the unique core-shell nanowire structure. The Au@Ni NAs electrode reveals excellent electrochemical property and desirable stability for catalyzing NaBH 4 electro-oxidation in basic solutions. The Au@Ni NAs electrode in the 2.00 M NaOH and 0.24 M NaBH 4 solution demonstrates an oxidation current density of 2.35 A mg −1 at −0.5 V (vs. Ag/AgCl), which is much higher than that of the noble metal catalysts previously reported, indicating that this material may be hopefully used as anodic catalysts for applying in fuel cells. [ABSTRACT FROM AUTHOR]