The Hierarchical Structures of Co3S4 Hollow Nanotube Arrays Wrapped with NiCo-Layered Double Hydroxide Nanosheets for High-Performance Asymmetric Supercapacitors

Cobalt-based sulfide is an excellent electrode material applied to supercapacitors (SCs) because of its good reversibility and abundant nanoforms. However, the feasibility of its practical application is reduced due to lack of stability and some difference with theoretical capacity. Herein, the hierarchical structures of Co3S4 hollow nanotube arrays wrapped with NiCo-layered double hydroxide nanosheets (Co3S4@NiCo-LDHs) are successfully fabricated on the nickel foam (NF) as the nonbinder electrode of SCs. Profiting from the synthetic effect of Co3S4 hollow nanotube arrays with effective diffusion channels, and NiCo-LDH nanosheets with a stable interconnected network, the prepared Co3S4@NiCo-LDH/NF composite electrode with a unique hierarchical structure attains an amazing areal capacity (7.45 C cm(-2) at 2 mA cm(-2)) and impressive cycle stability (87.7% through 5000 charge and discharge cycles). In addition, the assembled asymmetric supercapacitor (Co3S4@NiCo-LDH/NF//AC) shows pleasant energy density (0.661 mWh cm(-2) under 1.359 mW cm(-2)). The capacity of the assembled device can still be retained at 92% after 5000 cycles, which verifies the feasibility of the device in practical application.