Synthesis of core–shell ZnS@C microrods as advanced anode materials for lithium-ion batteries

Abstract

Zinc sulfide (ZnS) is considered as a candidate anode material to replace commercial graphite anodes in high-performance lithium-ion batteries (LIBs). However, the significant volume change during the lithiation/delithiation process leads to poor cycle and rate performance, severely limiting the application of the ZnS anode in LIBs. Here, core–shell ZnS@C microrods (ZnS@C MRs) were synthesized via a simple hydrothermal method, followed by in situ polymerization and a sulfidation process. Due to the rationally designed structure, the outer carbon shell can avoid the volume expansion of ZnS, thus maintaining the structural stability. Moreover, the carbon shell can not only enhance the conductivity, but also inhibit direct contact between ZnS and the electrolyte during the repeated lithiation/delithiation process. Accordingly, ZnS@C MRs exhibit outstanding electrochemical performance in LIBs. Specifically, a capacity of 392 mA h g⁻¹ is obtained after 500 cycles at 1.0 A g⁻¹. Moreover, a capacity of 162 mA h g⁻¹ is maintained at 3.0 A g⁻¹.