Carbon encapsulation and optimization of nanoparticle structure are key strategies in the development of battery electrode materials. Herein, we report a simple, one step chemical vapor deposition-like method to synthesize carbon encapsulated sandwich structured nanosheets/nanoribbons of ferrous sulphide (FeS@C NSRs) as a high performance sodium-ion battery anode material. The structurally advantageous FeS@C NSRs arises from heating Fe foam in the presence of a sulphur-containing resin, which supplies both the sulphur and carbon for the reaction. FeS@C NSRs maintains a high capacity of 582.8 mAh g⁻¹ at 0.1 A g⁻¹ for 120 cycles and a high rate capability of 270 mAh g⁻¹ at 10 A g⁻¹ for 2500 cycles. The impressive cycling performance results from fast electron and ion transfer with low structural strain on the bulk material. Furthermore, in situ Raman spectroscopy and XRD also reveal evidence that FeS@C NSRs cycles via a fully reversible conversion reaction pathway facilitated by the C–S–Fe bond. The efficient synthesis method could also be explored to produce other carbon coated transition metal sulphides for electrochemical applications.

碳封装和纳米颗粒结构优化是电池电极材料开发的关键策略。在此，我们报告了一种简单的一步化学气相沉积方法来合成碳封装的三明治结构纳米片/硫化亚铁纳米带（FeS@C NSR）作为高性能钠离子电池负极材料。结构上有利的 FeS@C NSR 是在含硫树脂存在下加热泡沫铁而产生的，含硫树脂为反应提供硫和碳。FeS@C NSR在0.1 A g ^{-1下循环120次后仍保持582.8 mAh g -1}的高容量，在10 A g ^{-1下保持270 mAh g -1}的高倍率性能2500 个周期。令人印象深刻的循环性能源于快速的电子和离子转移以及块体材料上的低结构应变。此外，原位拉曼光谱和 XRD 还揭示了 FeS@C NSRs 通过 C-S-Fe 键促进的完全可逆转化反应途径循环的证据。还可以探索有效的合成方法来生产其他用于电化学应用的碳包覆过渡金属硫化物。