A Few-Layer SnS2/Reduced Graphene Oxide Sandwich Hybrid for Efficient Sodium Storage

Rechargeable sodium-ion batteries have lately received considerable attention as an alternative to lithium-ion batteries because sodium resources are essentially inexhaustible and ubiquitous around, the world. Despite recent reports on cathode materials for sodium-ion batteries have shown electrochemical activities close to their lithium-ion counterparts, the major scientific challenge for sodintii-iOn batteries is to exploit efficient anode materials. Herein, We demonstrate that a hybrid material composed of few-layer SnS2 nanosheets sandWiched between reduced graphene oxide (RGO) nanosheets exhibits a high specific capacity of 843 mAh g(-1) (calculated based_ on the mass of SnS2 only) at a current density of 0,1 A and a 98% capacity retention after100 cycles when evaluated =between 0.01 and 2.5 V. Employing ex situ high-resolution transmission electron microscopy,and selected area electron diffiattion techniques, we illustrate the-high specific capacity of our anode through a 3-fold mechanism of intercalation Of sodium ions along the ab-plane of SnS2 nanosheets.and the ' i..thequerit. formation of Na2S2 and' Na15Sn4 thiorigh conversion arid alloy reactions. The existence of RGO nanosheets in the hybrid material functions as a flexible backbone and-high-speed electronic pathways, guaranteeing that an appropriate resilient space buffers the anisotropic dilation of SnS2 nanosheets along the ab-plane and c-axis for stable cycling performance.