Triaxial Nanocables of Conducting Polypyrrole@SnS2@Carbon Nanofiber Enabling Significantly Enhanced Li-Ion Storage

Two-dimensional (2D) SnS2 materials represent a class of high-capacity candidates as anodes of Li-ion batteries (LIBs); however, they are limited by inferior rate and cycling performance. Herein, we demonstrate unique triaxial nanocables of conducting polypyrrole@SnS2@carbon nanofiber (PPy@SnS2@CNF) prepared via a facile combination of hydrothermal method and vapor-phase polymerization. The PPy@SnS2@CNF manifests a strong synergistic effect from its hierarchical nanoarchitecture, which provides enlarged electrode/electrolyte contact interfaces, highly electrical conductive pathways, sufficient electrolyte ingress/transport channels, and an intimate mechanical/electrochemical safeguard for fast electrode kinetics and good structural stability. When evaluated as binder-free anodes of LIBs, the ternary nanocomposite delivers an ultrahigh reversible capacity of 1165 mAh g(-1) after 100 cycles and outstanding rate/cycling performance (880 mAh g(-1) at 2000 mA g(-1)), which are among the best results of the previously reported SnS2 electrodes. This work may pave a rational avenue of developing 2D materials with hierarchical structures for highly efficient energy-storage systems.