Vertically aligned, polypyrrole encapsulated MoS 2 /graphene composites for high-rate LIBs anode

Abstract Ultrathin MoS 2 nanosheets were vertically anchored on the reduced graphene oxide (MoS 2 /rGO) via hydrothermal method. To further engineering the surface conductivity, ultrathin polypyrrol (PPy) layer was coated on the MoS 2 /rGO composite via in situ polymerization to form a bi-continuous conductive network with a sandwich-like structure. The graphene nanosheets and the PPy coating can facilitate the electrons transfer rate, while the ultrathin MoS 2 nanosheets can enhance the utilization efficiency of the active materials. The obtained MoS 2 /rGO-10 composite exhibits high reversible specific capacity (970 mAh g −1 at 0.1 A g −1 ) and rate capability (capacity retention of 64% at 3.2 A g −1 ). Moreover, the PPy@MoS 2 /rGO hybrids reveal lower specific capacity but better rate capability, and a “trade-off” effect between electrons and ions transfer resistance was observed. This easy-scalable PPy surface conductivity engineering strategy may be applied in the preparation of high-performance LIBs active materials.