Rational Design of Unique ZnO/ZnS@N-C Heterostructures for High-Performance Lithium-Ion Batteries

Conversion-type anodes with high theoretical capacity have attracted enormous interest for lithium storage, although their extremely poor conductivity and volume variations during lithiation-delithiation processes seriously limit their practical applications. Herein, a facile strategy to fabricate ZnO/ZnS@N-C heterostructures decorated on carbon nanotubes (ZnO/ZnS@N-C/CNTs) with metal-organic framework assistance is developed. The as-prepared anodes display higher reversible capacity of 1020.6 mAh g^-1 at 100 mA g^-1 after 200 cycles and excellent high-cyclability with 386.6 mAh g^-1 at 1000 mA g^-1 over 400 cycles. The conductive CNT network and N-doped carbon shell could successfully improve the electrical conductivity and avoid the aggregation of ultrasmall ZnO/ZnS nanoparticles. The results calculated from density functional theory also suggest that the ZnO/ZnS heterostructures could promote electron-transfer capability.