Self-Supported Amorphous-Edge Nickel Sulfide Nanobrush for Excellent Energy Storage

Abstract

Transition metal sulfides, which attract great attention as pseudocapacitance electrodes with high specific capacitance exceeding those of traditional metal oxides, but still suffer from relatively low activity and inferior cycling life. Herein, freestanding and hierarchical nickel sulfide (NiS) electrodes with amorphous-edge and nanobrush structures (AENSNB) are successfully prepared based on the self-sacrificial nickel foam as Ni resource and a facile sulfurization process. Benefiting from the merits of amorphous-edge, hierarchical and self-growth architectures, the AENSNB electrode shows greatly improved electrochemical performance with high capacitance (5.59 F cm−2 at 10 mA cm−2). More importantly, it also exhibits a long cycling stability possessing 94.9% capacitance retention after 10000 cycles. The hybrid architecture design for crystalline NiS covered by amorphous edges can be deemed as an effective method to gain pseudocapacitive material for supercapacitors with good conductivity, long cycle life and excellent electrochemical activity.