摘要:
A binder-free Ni
3S
2 electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni
3S
2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni
3S
2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and~50 nm, respectively. The free space in the flowers and the thin feature of Ni
3S
2 buffered the volume changes and relieved mechanical strain during repeated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni
3S
2 electrode during cycling. The G/Ni-supported Ni
3S
2 maintained a reversible capacity of 250 mAh·g
-1 after 100 cycles at 50 mA·g
-1, demonstrating the good cycling stability as a result of the unique microstructure of this electrode material.