Exploring the Electrochemical Superiority of V₂O₅/TiO₂@Ti₃C₂-MXene Hybrid Nanostructures for Enhanced Lithium-Ion...

The use of vanadium(V)-based materials as electrode materials in electrochemical energy storage (EES) devices is promising due to their structural and chemical variety, abundance, and low cost. V-based materials with a layered structure and high multielectron transfer in the redox reaction have been actively explored for energy storage. Our current work presents the structural and electrochemical properties of a vanadium-based composite with TiO₂@Ti₃C₂ MXene, referred to as VM. This composite is obtained through the in situ thermal decomposition of the VO₂(OH)/Ti₃C₂mixture, which is achieved by solution mixing and drying. The material structure is confirmed using various characterization tools, which establish an orthorhombic V₂O₅ nanostructure compositing with nanocrystalline TiO₂@Ti₃C₂. VM with 5 wt % MXene, referred to as VM5, can achieve 460 mAhg^-1 at a current density of 0.1 Ag^1- and 290 mAhg^-1 at 1 Ag^1-, with an average coulombic efficiency of 98.5%. The presence of the V₂O₅/TiO₂ (nanocrystals) heterojunction attached with Ti₃C₂ sheets contributed to reduced charge transfer resistance. The cyclic stability shows a capacity retention of 62% over 500 cycles at 1 Ag^1- (4C rate, where 1C equals 0.25 Ag^1-) with a 0.22 capacity drop with each cycle. Dunn's approach to examining the charge storage mechanism demonstrates 72% contribution of the surface-dominant capacitive process and 28% of the diffusion-controlled intercalation process at 0.4 mVs^-1, suggesting a potential high-performance pseudocapacitive hybrid electrode material for lithium-ion batteries.