Highly faceted layered orientation in SnSSe nanosheets enables facile Li+-Diffusion channels

Abstract

Main attention to the interlayer regulation of layered metal chalcogenides (LMCs) is focused on the expansion of interlayer spacing to improve the Li+-storage performance. However, the issues of poor material homogeneity and complicated preparation make this strategy incapable to realize a wider application. In this work, a new interlayer design of the oriented growth of layered (00l) facets enables facile Li+-diffusion channels in SnSSe nanosheets. The further assembly between SnSSe nanosheets and reduced graphene oxide (SnSSe/rGO) generates flexible freestanding electrodes, in which the SnSSe nanosheets are tiled onto the rGO nanolayers with a planar configuration. The SnSSe/rGO electrodes demonstrate an ultrahigh discharge capacity of 2049 mAh g−1 at 0.1 A g−1 (based on the active mass of SnSSe) and a considerable capacity retention of 82% after 2000 cycles at 1 A g−1. The morphological characterization of long-life cycled SnSSe/rGO electrode confirms an open structure built with vertical lamellas, which can provide more active sites and accommodate the volume expansion–contraction of SnSSe nanosheets.