As a promising anode material for sodium-ion batteries, SnS has attracted increasing attention owing to its high theoretical capacity and abundant reserves. Unfortunately, the poor electrical conductivity and drastic volume changes lead to unsatisfactory cycling and rate performance, largely limiting its practical application. Herein, we report a pomegranate-like composite of heterostructured SnS/CoS spheres encapsulated in S, N dual-doped carbon framework (SnS/CoS@SNC) obtained by a simple ion adsorption, polymerization coating of polydopamine and subsequent calcination strategy. The integration of CoS with SnS particles with abundant interfaces can provide rich redox chemistry and accelerated ion diffusion kinetics, while the coated S, N dual-doped carbon shell enables good electrical conductivity and reinforced structural integrity as well by accommodating the volume changes and inhibiting the collapse/pulverization of active materials during the cycling process. As a consequence, the pomegranate-like heterostructured SnS/CoS@SNC anode exhibited a higher capacity (743 mAh g at 1 A g), excellent rate capability (213 mAh g at 50 A g) and outstanding cycling stability (560 mAh g at 5 A g after 1000 cycles), showing the application feasibility of this anode material for developing high-rate and durable SIBs.

中文翻译：

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类石榴异质结构 SnS2/CoS2 颗粒封装在 S、N 双掺杂碳框架中，可实现高速率和持久的钠离子存储

SnS作为一种有前景的钠离子电池负极材料，因其高理论容量和丰富的储量而受到越来越多的关注。不幸的是，较差的导电性和剧烈的体积变化导致循环和倍率性能不理想，很大程度上限制了其实际应用。在此，我们报道了通过简单的离子吸附、聚多巴胺聚合涂层和随后的煅烧策略获得的封装在S、N双掺杂碳骨架中的异质结构SnS/CoS球体的石榴状复合材料（SnS/CoS@SNC）。 CoS与具有丰富界面的SnS颗粒的集成可以提供丰富的氧化还原化学和加速的离子扩散动力学，而涂覆的S、N双掺杂碳壳可以通过适应体积变化和抑制体积变化来实现良好的导电性和增强的结构完整性。循环过程中活性材料的塌陷/粉碎。因此，类石榴异质结构SnS/CoS@SNC负极表现出更高的容量（1 A g-1时为743 mAh g）、优异的倍率性能（50 A g-1时为213 mAh g）和出色的循环稳定性（560 mAh g-1）。 1000次循环后为5 A g），显示了该负极材料在开发高倍率和耐用SIB方面的应用可行性。