Layered metal sulphides are promising anode materials for sodium-ion batteries (SIBs) and capacitors owing to their distinctive crystal structures and large interlayer spacings, which are suitable for Na⁺ insertion/extraction. However, low electronic conductivity, sluggish ion transfer and large volume variation of metal sulphides during sodiation/desodiation processes have hindered their practical application. In this work, we report the construction of a walnut-like core–shell MoS₂@SnS heterostructure composite as an anode for SIBs with high capacity, remarkable rate and superior cycling stability. Experimental observations and first-principles density functional theory (DFT) calculations reveal that the enhanced electrochemical performances can be mainly ascribed to the boosted charge transfer and ion diffusion capabilities at the heterostructure interface driven by a self-building internal electric field. Our findings herein may pave the way for the development of novel heterostructure composite materials for beyond lithium-ion batteries and capacitors.

中文翻译：

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MoS2 @ SnS异质结构用于钠离子存储，具有增强的动力学。

层状金属硫化物由于其独特的晶体结构和较大的层间距，特别适合用于Na ⁺插入/萃取，因此是钠离子电池（SIB）和电容器的有希望的阳极材料。但是，低电导率，缓慢的离子转移以及在硫化/脱氧过程中金属硫化物的体积变化较大，阻碍了它们的实际应用。在这项工作中，我们报告了类似核桃壳核的MoS ₂的构造@SnS异质结构复合材料作为SIB的阳极，具有高容量，显着的速率和出色的循环稳定性。实验观察和第一性原理密度泛函理论（DFT）计算表明，增强的电化学性能主要归因于自建内部电场驱动的异质结构界面上电荷转移和离子扩散能力的增强。我们在本文中的发现可能为锂离子电池和电容器以外的新型异质结构复合材料的开发铺平道路。