Strengthening the Interface between Flower‐Like VS₄ and Porous Carbon for Improving Its Lithium Storage Performance

Abstract

Carbon materials are frequently used to improve the cycle and rate performance of VS 4 as anode material for lithium ion batteries. However, the interfacial interaction between VS 4 and carbon has not been elucidated clearly. Various VS 4 @C composites are prepared and the interface between VS 4 and porous carbon is investigated by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and first-principles calculations. The interfacial structure between VS 4 and carbon and the mechanism of flower-like VS 4 growth on carbon substrate are revealed clearly. The results indicate that C−V bonds and C−O−V bonds are formed when oxygen functional groups are introduced into the porous carbon, and the C−V bonds and C−O−V bonds accelerate the electron transport and enhance structural stability of the VS 4 @C composite. Deriving from the unique structure and robust interfacial interaction, the electrochemical performances of VS 4 @C composite are much better than that of pure VS 4 . Moreover, through the study of lithium storage mechanism of VS 4 anode, it is found that there is an irreversible amorphization change of the original VS 4 in the first cycle, and that during the following electrochemical process, the main storage behavior of lithium ions derives from the insertion−extraction reactions in the amorphous VS 4 with the reaction between V 4+ and V 3+ .

Strongly Coupled Interfacial Engineering Inspired by Robotic Arms Enable High‐Performance Sodium‐Ion Capacitors

“…Meanwhile, the other two obvious peaks at 516.6 and 524.1 eV are attributed to the 2p 3/2 and 2p 1/2 components of V 3+ . Compared to the V 2p spectrum of pure VS 4 (Figure S3, Supporting Information), unusual peaks located at 514.2 and 521.8 eV confirm the formation of VC bonds in VS 4 -CNT and VS 4 /CNT, [18] which is consistent with the results in Raman spectra, and no obvious interfacial bonds could be noticed in VS 4 /CNT. Significantly, numerous VOC (23.3%) and VC (24.5%) bonds have been observed after the acidification of CNT bundles.…”

Stabilizing Intermediate Phases via Efficient Entrapment Effects of Layered VS4/SnS@C Heterostructure for Ultralong Lifespan Potassium‐Ion Batteries

“…Particularly, ν (V‐S‐V) doubly bonded S 2– and the ν (VS) terminal S stretches of VS 4 crystal occurred at 523 and 993 cm –1 , respectively, demonstrates the existence of VS 4 components in VS 4 /SnS@C composite. [ 41,42 ] Furthermore, the intense couple of peaks at around 1353 and 1593 cm –1 probably derive from the defect‐induced D band and graphite G band of external graphene scaffold, respectively. [ 43 ] In addition, the carbon content of the as‐prepared VS 4 /SnS@C is calculated to be 19.5% measured from 30 to 800 °C in the air atmosphere (Figure 2c).…”

Self‐Assembled VS4 Hierarchitectures with Enhanced Capacity and Stability for Sodium Storage

“…72-1294) with no observable impurity peak, confirming that the as-prepared sample is pure VS 4 . [19,29] To study the chemical composition of VS 4 -CN-Hs, energy dispersive spectroscopy (EDS), XPS, and Raman spectroscopy were used and the results are displayed in Figure 1b-d…”