Vulcanization induced composition regulation of NiO electrode materials with improved electrochemical performances

It is well known that the electrochemical performances of electrode materials seriously depend on their shapes and structures. In this work, we synthesize NiO/Ni_xS_y microspheres by a simple hydrothermal route and vulcanization process. The as-obtained products are used as supercapacitor electrode materials. It delivers a capacitance of 1529.29 F g^-1 at 1 A g^-1. An asymmetric capacitor using NiO/Ni_xS_y as positive electrode is assembled, which keeps capacitive retention of 85.23% (10,000 cycles). The excellent electrochemical performance of NiO/Ni_xS_y electrode can be ascribed to the addition of sulfur and synergistic effect between NiO and Ni_xS_y structures. It shows that the as-prepared products can be potential electrode materials for emerging energy storage devices.