Hierarchical Structure Of Self-Supported Nico2s4 Nanoflowers@Nico2s4 Nanosheets As High Rate-Capability And Cycling-Stability Electrodes For Advanced Supercapacitor

Hierarchical nanostructure of materials can protect themselves from damage and improve the stability in elec-trochemical reaction as electrode materials, increasing active sites and ion adsorption, and then strengthen the electrochemical performance for supercapacitors. In this work, hierarchical NiCo2S4 nanoflowers@NiCo2S4 nanosheets (NiCo2S4 NFs@NiCo2S4 NSs) composite was fabricated on Ni foam substrate via facile and low-cost multistep hydrothermal methods. As a result, the NiCo2S4 NFs@NiCo2S4 NSs with unique hierarchical nano-structure demonstrates prominent rate property with the capacity of 338.1 mAh/g at 1 A/g and 290.1 mAh/g at 10 A/g. In addition, the cycling stability of the NiCo2S4 NFs@NiCo2S4 NSs is enhanced significantly (capacitance loss of 8% after 4000 cycles) on account of distinct and stable microarchitecture. Furthermore, the assembled NiCo2S4 NFs@NiCo2S4 NSs//NiCo2S4 NFs@NiCo(2)S(4)NSs symmetrical supercapacitor (SSC) device proves a favorable power density of 750 W/kg at energy density of 18.04 Wh/kg with cycling stability of 89% after 4000 charge/discharge cycles. This strategy is offered to generate the unique and low-cost hierarchical electrode structure leading excellent electrochemical properties and demonstrating its application prospect as electrode material.