One step synthesis of SnS2 nanosheets assembled hierarchical tubular structures using metal chelate nanowires as a soluble template for improved Na-ion storage

- A soluble template strategy is used to build hierarchical SnS2 tubular structures.
- The shell growth and subsequent core dissolution are realized in one step reaction.
- SnS2 nanosheets possess maximally exposed edges for efficient Na-ion intercalation.
- One dimensional tubular structure provides a continuous charge transport pathway.
- Hierarchical SnS2 tubular structures are promising candidates for Na-ion batteries.

SnS2 material is considered as a promising anode material for Na-ion batteries (NIBs) because of its unique layered structure and high theoretical capacity. However, SnS2 nanosheets are easily overlapped during synthesis and cycling process. Also, they have to experience large volume change during repeated sodiation-desodiation processes. A promising concept is the application of hierarchical hollow structures for improving electrode stability upon cycling. However, they usually rely on template methods that require complex procedures such as chemical etching or calcination to remove inner template. Here, we demonstrate a simple and innovative strategy for fabricating the SnS2 nanosheets assembled hierarchical tubular structures (SnS2 NS ⊂ HTSs) by using cobalt-nitrilotriacetic acid chelate nanowires as soluble template, which makes shell growth and core template dissolution occur simultaneously in one step reaction. Owing to the hollow interior and well separated nanosheets with maximally exposed edges, the SnS2 NS ⊂ HTSs exhibit excellent electrochemical performance. When evaluated as the anode material for NIBs, it delivers a high discharge capacity of 708 mAh g−1 at 50 mA g−1 and still remains up to 414 mAh g−1 after 50 cycles.

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