Construction of Hierarchical Nanotubes Assembled from Ultrathin V3S4@C Nanosheets towards Alkali-Ion Batteries with Ion-Dependent Electrochemical Mechanisms

Ultrathin core-shell V3S4@C nanosheets assembled into hierarchical nanotubes (V3S4@C NS-HNTs) are synthesized by a self-template strategy and evaluated as general anodes for alkali-ion batteries. Structural/physicochemical characterizations and DFT calculations bring insights into the intrinsic relationship between crystal structures and electrochemical mechanisms of the V3S4@C NS-HNTs electrode. The V3S4@C NS-HNTs are endowed with strong structural rigidness owing to the layered VS2 subunits and interlayer occupied V atoms, and efficient alkali-ion adsorption/diffusion thanks to the electroactive V3S4-C interfaces. The resulting V3S4@C NS-HNTs anode exhibit distinct alkali-ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in storage of K+, benefiting from synergistic contributions of pseudocapacitive and reversible intercalation/de-intercalation behaviors superior to those of the conversion-reaction-based Li+-/Na+-storage counterparts.