Carbon Nanorod−MoS2 Core−Sheath Heterostructure and Its Electrochemical Properties over Various Electrochemical Windows

Abstract The powder of a carbon nanorod−MoS 2 core−sheath heterostructure is successfully synthesized by using a hydrothermal method. The carbon nanorod−MoS 2 material is composed of hierarchical MoS 2 nanosheets tightly grown on carbon nanorods, in which the carbon nanorods as a template effectively reduce the aggregation of the MoS 2 nanosheets. The electrochemical properties of the carbon nanorod−MoS 2 composite electrode are studied in detail, as the intercalation of lithium into MoS 2 includes two significant changes in lithiation mechanism, which occur over various electrochemical windows, such as from 1.0 to 3.0 V and from 0.001 to 3.0 V. The former mainly corresponds to the intercalation/extraction of lithium cations, and thus it presents excellent cyclic stability but low specific capacity. The later causes a big phase change in the final Li‐Sulfur battery system, and thus delivers a high specific capacity but is accompanied by serious pulverization and consequential fast capacity fading. MoS 2 supported by carbon nanorods presents a better electrochemical performance than the pure MoS 2 sample over various electrochemical windows.