Titanium disulfide (TiS2) is investigated as an advanced conversion electrode for sodium (Na)‐ion batteries (NIB) in an ether‐based electrolyte (NaPF6/glyme (DME)). The as‐prepared TiS2 demonstrates a high reversible capacity of 1040 mA h g−1 at 0.2 A g−1 with the capacity contribution of 521 mA h g−1 in the voltage region below 1.0 V (vs Na/Na+), remarkable initial coulombic efficiency of 95.9% and superior rate capability of 621 mA h g−1 at 40 A g−1. The high conductivity of the Ti‐based compounds and nanosized particles generated by chemical conversion reactions could minimize the entropic barrier for the reversible conversion, resulting in high reversibility and ultrafast charge/discharge ability of the electrode. Moreover, with its strong ability to adsorb soluble polysulfide intermediates, the as‐prepared TiS2 electrode exhibits superior cycling stability over 9000 cycles, serving as a stable and ultra‐high capacity conversion electrode for NIBs.

Benefiting from the unique structure of ultrafine NiSx nanospheres uniformly wrapped in the in situ S-doped rGO matrix, the NiSx–rGOS electrode delivers a high reversible capacity of 516 mA h g−1 at 0.2 A g−1 and a remarkable rate performance of 414 mA h g−1 at 4 A g−1, offering a low cost and high performance anode material for Na-ion batteries.

Nanoengineering of metal electrodes are of great importance for improving the energy density of alkali-ion batteries, which have been deemed one of most effective tools for addressing the poor cycle stability of metallic anodes. However, the practical application of nanostructured electrodes in batteries is still challenged by a lack of efficient, low-cost, and scalable preparation methods. Herein, we propose a facile chemical dealloying approach to the tunable preparation of multidimensional Sb nanostructures. Depending on dealloying reaction kinetics regulated by different solvents, zero-dimensional Sb nanoparticles (Sb-NP), two-dimensional Sb nanosheets (Sb-NS), and three-dimensional nanoporous Sb are controllably prepared via etching Li−Sb alloys in H 2 O, H 2 O-EtOH, and EtOH, respectively. Morphological evolution mechanisms of the various Sb nanostructures are analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction measurements. When applied as anodes for sodium ion batteries (SIBs), the as-prepared Sb-NS electrodes without any chemical modifications exhibit high reversible capacity of 620 mAh g −1 and retain 90.2% of capacity after 100 cycles at 100 mA g −1 . The excellent Na + storage performance observed is attributable to the twodimensional nanostructure, which ensures high degrees of Na + accessibility, robust structural integrity, and rapid electrode transport. This facile and tunable approach can broaden ways of developing high performance metal electrodes with designed nanostructures for electrochemical energy storage and conversion applications.

Prussian blue analogues (PBAs) are considered one of the promising cathodes for sodium-ion batteries because of their low cost and tunable structure. As an intrinsic characteristic, the influence of structured water in PBAs on the electrochemical properties is still controversial. Herein, low-vacancy iron hexacyanoferrate with different interstitial water contents is synthesized through the citric acid-assisted single iron source method. Ex situ Fourier transform infrared and X-ray diffraction characterization reveals that the interstitial water can stably exist in the Prussian blue framework during repeated cycling. The longstanding interstitial water can reduce the volume change during the Na + insertion/extraction process, resulting in improved cycling stability. Thanks to the low Fe(CN) 6 4− vacancies and pillar role of interstitial water in the crystal framework, the HW-PB exhibits a high reversible capacity of 117 mAh g −1 and excellent long cycle performance with a capacity retention of 91% after 1380 cycles. This work broadens the understanding of the relationship between the interstitial water in PBAs and Na-storage performances, providing guidance for the precise synthesis of high-quality PBAs.