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Alloying metal selenides as advanced anode materials for sodium‐ion devices requires overcoming the challenges of high diffusion energy barriers and large volume expansion at high‐power densities. The typical dealloying process is difficult to trigger under fast kinetics, leading to limited capacity utilization. Here, Sb/W‐hybridization precursor is synthesized by one‐step reaction, followed by electrostatic spinning strategy to achieve a localized domain‐limiting effect. Finally, the carbon mediated Sb2Se3–WSe2 heterostructure nanofiber (SbWSe/C/NF) are obtained after carbonization/selenization process. Physical characterization and theoretical calculations reveal that the SbWSe/C/NF‐500 has a heterogeneous structure and abundant edge carbon defects, facilitating rapid Na+ transfer from exterior to interior. Furthermore, compared with the Sb2Se3/C monomer, the SbWSe/C heterostructure shows a significant dealloying reaction at high current densities, enhancing capacity utilization. Resultantly, the Na half‐cell with SbWSe/C/NF‐500 electrode demonstrates excellent rate capability and a high specific capacity of 553.7 mA h g−1 after 250 cycles at 2 A g−1. Meanwhile, the assembled sodium‐ion capacitor exhibits 80.83% capacity retention after 8000 cycles at 3800 W kg−1. The structure design strategy of cationic heterostructures with dual‐carbon introduction provides a reference for developing high‐power anodes. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries are attracting great attention as an alternative to lithium‐ion batteries due to the lower cost and better sustainability of sodium. Although the metal sulfide‐based anodes demonstrate much higher theoretical capacity than the hard carbon anodes, the severe capacity degradation and inferior rate capability caused by poor electrical conductivity and sluggish kinetics hinder their applications. Herein, a novel bimetallic sulfide‐based anode wrapped by reduced graphene oxide (i.e., Bi2S3/VS4/rGO) is presented, in which the heterointerfaces between Bi2S3 and VS4 are well distributed among the composite, leading to the promoted charge transfer and the improved Na+ transport kinetics. Combined with electrolyte optimization, the Bi2S3/VS4/rGO demonstrates excellent electrochemical performance, including excellent rate capabilities over 10 A g−1, and a long lifespan over 1000 cycles. This work indicates the significance of the synergistic effect of structure regulation and electrolyte optimization for achieving fast‐charging performance. [ABSTRACT FROM AUTHOR]

Oxygen‐containing functional groups (OFGs) grafted by carbon materials surface can serve as active sites to reversibly store potassium and simultaneously contribute to forming a stable solid‐electrolyte interphase layer, leading to increased capacity and cycling stability. However, the excessive OFGs will damage conductivity and hence causes the increase in electron transfer resistance, easily resulting in a poor rate. Herein, it is theoretically demonstrated that the embedded metallic Co particles can synergize with C‐O‐C moieties in OFGs to accelerate K‐ion adsorption (△E = −1.62 eV) and regulate electronic structure, ensuring high capacity and rate. In view of this, O‐doped carbon with implanted Co is well established, and it is found that pyrolysis temperature can effectively regulate Co content and C‐O‐C proportion. Various characterizations unveil that the introduced Co species not only evidently promote the adsorption capability of C‐O‐C to K‐ion, but catalyze the generation of graphitic carbon. Benefiting from these merits (e.g., enhanced adsorption ability and electronic conductivity), the sample with the optimal Co content and C‐O‐C proportion presents a high capacity of 254.7 mAh g−1 and an excellent rate capability (202.9 mAh g−1 at 2 A g−1). The unique design route makes fast and stable K‐storage of carbon anode possible. [ABSTRACT FROM AUTHOR]

Potassium‐ion batteries (PIBs) exhibit a considerable application prospect for energy storage systems due to their low cost, high operating voltage, and superior ionic conductivity. As a vital configuration in PIBs, the two‐phase interface, which refers to K‐ion diffusion from the electrolyte to the electrode surface (solid–liquid interface) and K‐ion migration between different particles (solid–solid interface), deeply determines the diffusion/reaction kinetics and structural stability, thus significantly affecting the rate performance and cyclability. However, researches on two‐phase interface are still in its infancy and need further attentions. This review first starts from the fundamental understanding of solid–liquid and solid–solid interfaces to in‐depth analyzing the effect mechanism of different improvement strategies on them, such as optimization of electrolyte and binders, heterostructure design, modulation of interlayer spacing, etc. Afterward, the research progress of these improvement strategies is summarized comprehensively. Finally, the major challenges are proposed, and the corresponding solving strategies are presented. This review is expected to give an insight into the importance of two‐phase interface on diffusion/reaction kinetics, and provides a guidance for developing other advanced anodes in PIBs. [ABSTRACT FROM AUTHOR]

Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal–organic framework (MOF, Mil‐125) was used as a precursor and template to successfully synthesize the porous mooncake‐shaped Li4Ti5O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake‐shaped LTO material. The SmF3‐modified LTO maintained a porous mooncake‐shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+, reduce the polarization of electrode, decrease charge transfer impedance (Rct) and solid electrolyte interface impedance (Rsei), and increase the lithium ion diffusion coefficient (DLi), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake‐shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g−1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g−1), and shows a high retention rate of 96.4 % after 500 cycles at 5 C‐rate. [ABSTRACT FROM AUTHOR]