Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room-temperature sodium-ion batteries (SIBs). Herein, we report high crystalline and Na-rich Prussian white Na CoFe(CN) nanocubes synthesized by an optimized and facile co-precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na CoFe(CN) nanocubes exhibited an initial capacity of 151 mA h g , which is close to its theoretical capacity (170 mA h g ). Meanwhile, the Na CoFe(CN) cathode demonstrated an outstanding long-term cycle performance, retaining 78 % of its initial capacity after 500 cycles. Furthermore, the Na CoFe(CN) Prussian white nanocubes also achieved a superior rate capability (115 mA h g at 400 mA g , 92 mA h g at 800 mA g ). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na ions through large channels in the open-framework. Most noteworthy, the as-prepared Na CoFe(CN) nanocubes are not only low-cost in raw materials but also contain a rich sodium content (1.87 Na ions per lattice unit cell), which will be favorable for full cell fabrication and large-scale electric storage applications.

Cost-effective material with a rational design is significant for both sodium-ion batteries (SIBs) and electromagnetic wave (EMW) absorption. Herein, we report an elaborate yolk–shell FeS2@C nanocomposite as a promising material for application in both SIBs and EMW absorption. When applied as an anode material in SIBs, the yolk–shell structure not only facilitates a fast electron transport and shortens Na ion diffusion paths but also eases the huge volume change of FeS2 during repeated discharge/charge processes. The as-developed FeS2@C exhibits a high specific capacity of 616 mA h g–1 after 100 cycles at 0.1 A g–1 with excellent rate performance. Furthermore, owing to the significant cavity and interfacial effects enabled by yolk–shell structuring, the FeS2@C nanocomposite delivers excellent EMW absorption properties with a strong reflection loss (−45 dB with 1.45 mm matching thickness) and a broad 15.4 GHz bandwidth. This work inspires the development of high-performance bifunctional materials.

Rationally designed yolk–shell structured N-doped carbon coated FeS2nanocages demonstrate superior high-rate and long-term cycling performance as anode materials for sodium-ion batteries.

Tin disulfide, as a promising high-capacity anode material for sodium-ion batteries, exhibits high theoretical capacity but poor practical electrochemical properties due to its low electrical conductivity. Constructing heterostructures has been considered to be an effective approach to enhance charge transfer and ion-diffusion kinetics. In this work, composites of SnS /Sb S heterostructures with reduced graphene oxide nanosheets were synthesized by a facile one-pot hydrothermal method. When applied as anode material in sodium-ion batteries, the composite showed a high reversible capacity of 642 mA h g at a current density of 0.2 A g and good cyclic stability without capacity loss in 100 cycles. In particular, SnS /Sb S heterostructures exhibited outstanding rate performance with capacities of 593 and 567 mA h g at high current densities of 2 and 4 A g , respectively, which could be ascribed to the dramatically improved Na diffusion kinetics and electrical conductivity.

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