Combining two different compounds into a heterostructure recently emerged as an auspicious strategy to mitigate the issues associated with the sluggish sodium diffusion kinetics of anode materials. Nevertheless, studies relating to as-designed heterostructures, so far, have not considered the matching of crystal structures between different compounds. In this work, a heterostructure between MnS and FeS₂, featuring identical cubic systems and close lattice parameters, confined in one-dimensional carbon nanofibers was synthesized through electrospinning technology (denoted as MnS/FeS₂@CNFs). An internal built-in electric field is generated at the interface of the heterostructure owing to differences in the bandgaps of the two compounds, and this is conducive to accelerating the Na⁺ diffusion kinetics and enhancing charge transport. Meanwhile, the one-dimensional carbon skeleton can effectively alleviate volume variations and prevent the aggregation of active material during the sodium storage process. As expected, the MnS/FeS₂@CNFs composite delivered good rate performance (322.3 mA h g⁻¹ at 10.0 A g⁻¹) and excellent cycling durability (194.0 mA h g⁻¹ at 10.0 A g⁻¹ over 3600 cycles). In line with DFT calculations, the constructed heterojunction with a small mismatch of ∼3.9% can effectively enhance the electronic conductivity of the composite, thereby accelerating charge transfer. This work can help the development of rational design strategies for heterostructures and provide an in-depth understanding of the functions of heterostructures in the energy-storage field.

中文翻译：

---

具有高度晶格匹配的 MnS/FeS2 异质结构锚定在碳骨架中，用于超稳定的钠离子存储

将两种不同的化合物组合成异质结构最近成为缓解与阳极材料钠扩散动力学缓慢相关问题的一种有利策略。然而，到目前为止，与设计的异质结构相关的研究尚未考虑不同化合物之间晶体结构的匹配。在这项工作中，通过静电纺丝技术（表示为 MnS/FeS ₂ @CNFs）合成了限制在一维碳纳米纤维中的MnS 和 FeS ₂之间的异质结构，具有相同的立方系统和紧密的晶格参数。由于两种化合物的带隙不同，异质结界面处产生内建电场，有利于加速Na⁺扩散动力学和增强电荷传输。同时，一维碳骨架可以有效缓解体积变化，防止钠储存过程中活性物质的聚集。正如所料，MnS系/的FeS _2个@CNFs复合递送良好的倍率性能（322.3毫安汞柱^-1 10.0 A G ^-1）和优异的循环耐久性（194.0毫安汞柱^-1 10.0 A G ^-1超过 3600 次循环）。与 DFT 计算一致，构建的具有约 3.9% 小失配的异质结可以有效提高复合材料的电子电导率，从而加速电荷转移。这项工作有助于制定合理的异质结构设计策略，并深入了解异质结构在储能领域的功能。