Hollow spheres constructed by ZnS-CoS2 @N-doped carbon@N-doped carbon as anodes for high-performance sodium-ion batteries

Hollow spheres constructed by ZnS-CoS2@N-doped Carbon@N-doped carbon (ZnS-CoS2@NC@NC) are successfully synthesized using template method combined with NC coating procedure. For SIBs anode, ZnS-CoS2@NC@NC electrode exhibits excellent rate property and sustainable capacity of 164 mAh g-1 at 5 A g-1 after 1000 cycles. The superior sodium storage performance for ZnS-CoS2@NC@NC composites is benefited from its distinctive structure, in which the hollow architecture for ZnS/CoS2@NC@NC composites can buffer the volume change of ZnS/CoS2 and enhance electronic/ionic conductivity within charge/discharge processes. Furthermore, the NC shell layer can further alleviate structural degradation of ZnS/CoS2@NC@NC hollow spheres, and supply more effective active sites.