Paper Title
Applied Potential-Dependent Performanceforthe Nickel Cobalt Oxysulfide Nanotube/Nickel Molybdenum Oxide Nanosheet Core-Shell Structureon Energy Storage and Oxugen Evolutoin

Abstract
Nickel cobalt sulfide is widely applied to energy storage and electrocatalysis owing to the high electrical conductivity and multiple oxidation states. This study proposes NiCo2S4 and NiCo2OxSy@NiMoO4 core-shell structures as energy storage materials and electrocatalysts for oxygen evolution reactions. A higher specific capacity of 2.22 mAh cm-2 (168.18 mAh g-1)at 10 mA cm-2is obtained for the NiCo2OxSy@NiMoO4 electrode which is applied as the battery-type electrode for the battery supercapacitor hybrid, but the better electrocatalytic activity is achieved for the NiCo2S4 electrode witha smaller overpotential of 1.567 VRHEat 0.12 A cm-2and asmaller Tafel slope of 86.1 mV dec-1. The electrochemically active surface area (ECSA) is larger for NiCo2S4 due to the nanoparticle-assembled nanotube wall, whereas NiCo2OxSy@NiMoO4 shows higher electrical conductivity owing to the molybdenum participation. Different performances on energy storage and electrocatalysis for NiCo2S4 and NiCo2OxSy@NiMoO4nanomaterials are caused by different potentials applied for driving the electrochemical reactions. Keywords - Battery Super Capacitor Hybrid; Core-Shell; Electrocatalyst; Nickel Cobalt Oxysulfide; Nickel Cobalt Sulfide