In this work, the core‐shelled Sb@Sb2O3 heterostructure encapsulated in 3D N‐doped carbon hollow‐spheres is fabricated by spray‐drying combined with heat treatment. The novel core‐shelled heterostructures of Sb@Sb2O3 possess a mass of heterointerfaces, which formed spontaneously at the core‐shell contact via annealing oxidation and can promote the rapid Na+/K+ transfer. The density functional theory calculations revealed the mechanism and significance of Na/K‐storage for the core‐shelled Sb@Sb2O3 heterostructure, which validated that the coupling between the high‐conductivity of Sb and the stability of Sb2O3 can relieve the shortcomings of the individual building blocks, thereby enhancing the Na/K‐storage capacity. Furthermore, the core‐shell structure embedded in the 3D carbon framework with robust structure can further increase the electrode mechanical strength and thus buffer the severe volume changes upon cycling. As a result, such composite architecture exhibited a high specific capacity of ≈573 mA h g−1 for sodium‐ion battery (SIB) anode and ≈474 mA h g−1 for potassium‐ion battery (PIB) anode at 100 mA g−1, and superior rate performance (302 mA h g−1 at 30 A g−1 for SIB anode, while 239 mA h g−1 at 5 A g−1 for PIB anode).

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Constructing sodium-ion battery anodes with efficient ion/electron transport and high cycling stability is significantly promising for applications but still remains challenging. Here, "three-in-one" multi-level design is performed to develop a carbon-coated phosphorous-doped MoS 2 anchored on carbon nanotube paper (P-MoS 2 @C/CNTP). The Na + diffusion and electron transport, as well as the structural stability of the whole anode are simultaneously enhanced through the synergistically optimization of P-MoS 2 @C/CNTP at atomic, nanoscopic, and macroscopic levels. Resulted from the multi-level modification, the synergetic mechanism has been demonstrated by electrochemical measurement and theoretical calculation. As a result, the freestanding P-MoS 2 @C/CNTP anode presents a high rate performance (150 mA h g −1 at 5 A g −1 ) and a long cycling life (1 A g −1 , 1200 cycles, 249 mA h g −1 ). This work provides a new approach to the design and fabrication of high-performance conversion-type electrode materials for rechargeable batteries application.

Resource‐rich FeS2 is a promising anode for potassium‐ion batteries (PIBs). However, polysulfides emerge due to FeS2 conversion during discharging, which dissolve into the ether‐based electrolyte and cause the continuous capacity degradation in PIBs. To address the polysulfides dissolution in PIBs, a graphene–shell‐encapsulated FeS2 is fabricated and embedded in N/S codoped 3D hollow carbon spheres. As a protective pocket, the graphene–shell can effectively accommodate polysulfides inside the core–shell, inhibiting the polysulfides shuttle effect to enhance cycle stability of electrode. The density functional theory (DFT) calculations demonstrate that graphene–shells have a strong adsorption capacity for polysulfides, and the interfacial interaction between KFeS2 and graphene–shell can boost the K ion mobility. As a result, the composite exhibits superior‐rate properties (524 and 224 mA h g−1 at 0.1 and 8 A g−1, respectively) and long‐term cycle stability. This work demonstrates the promotion and protective effect of the graphene–shell for the FeS2 to storage K from both experimental and computational perspectives. These research outputs can provide guidance for designing other metal‐based sulfide electrodes for PIBs.