Urchinlike ZnS Microspheres Decorated with Nitrogen-Doped Carbon: A Superior Anode Material for Lithium and Sodium Storage.

Urchinlike ZnS microspheres decorated with nitrogen-doped carbon (ZnS@NC) were fabricated by a facile two-step method in which urchinlike ZnS microspheres were coated with polydopamine and then calcined in an inert gas atmosphere. When employed as the anode material for lithium-ion batteries and sodium ion batteries, ZnS@NC exhibits a reversible lithium-storage capacity of 690 mAh g-1 after 100 cycles at 100 mA g-1 and a reversible sodium-storage capacity of 460 mAh g-1 after 80 cycles at 200 mA g-1 .The ZnS@NC electrode shows a high reversible lithium-storage capacity of 520 mAh g-1 after 200 cycles and a high reversible sodium-storage capacity of 380 mAh g-1 after 100 cycles even at a current density of 1 A g-1 . The superior electrochemical performance could be ascribed to structural merits of the urchinlike ZnS microspheres and synergistic effects between ZnS and polydopamine-derived nitrogen-doped carbon. The lithium- and sodium-storage capacities of urchinlike ZnS@NC microspheres are in the top rank in comparison with those reported in other studies.