Flower-like carbon spheres formed by self-assembly of nitrogen-doped porous nanoribbons to boost SnS2 nanosheets for advanced lithium storage

Abstract

SnS2 is a two-dimensional layered material with high theoretical capacity, but its further application in lithium-ion batteries is limited by problems such as low intrinsic conductivity and dramatic volume expansion during lithiation process. Therefore, SnS2 nanosheets were designed to anchor in the interlayer nanospaces of flower-like carbon spheres self-assembled from nitrogen-doped porous carbon nanoribbons (SnS2/N-FC). Nitrogen-doped porous nanoribbons facilitated the uniform distribution of SnS2 nanosheets in the interlayer nanospaces of the flower-like carbon spheres, establishing a face-to-face interaction with the nanoribbons and the SnS2 nanosheets. This composite structure enhances the transfer of electrons between the components. In addition, the integration of spherical flower-like electrodes with the reserved interlayer nanospaces provided a buffering space for volume expansion which ensured an even distribution of mechanical stress. As a result, SnS2/N-FC exhibited a high reversible specific capacity of 1322.3 mAh g−1 after 200 cycles at 0.1 A g−1, with the capacity kept growing to 1329.4 mAh g−1 after 1000 cycles at 1 A g−1. This study introduces a novel approach for the design of anode materials which demonstrate excellent lithium storage.