V2CTx-carbon nanotube/graphene nanohybrids for Li-ion storage applications

In this study, we synthesized carbon nanohybrids of V2CTx MXene to enhance its electrochemical performance in Li-ion storage systems. The nanohybrids were hybridized with carbon nanotubes (CNTs) and graphene (Gr) with a weight ratio of MXene to carbon of 95:5. XPS analysis revealed a high oxygen termination ratio and increased pi-pi* bond intensity in the nanohybrids. By creating a three-dimensional structure, the nanohybrids exhibited an increase in specific surface area. The electrochemical and Li-ion storage properties of V2CTx MXene and its carbonaceous nanohybrids were investigated using electrochemical impedance and galvanostatic chargedischarge tests. The hybridization improved the electrode's electrical conductivity and reduced charge transfer resistance. The V2CTx MXene demonstrated a remarkable specific discharge capacity, reaching 388.5 mAh g-1 at a current rate of 100 mA g-1 and maintaining 99.4 % Coulombic efficiency after 140 cycles. Additionally, the discharge capacities at a current rate of 100 mA g-1 for V2CTx/5CNT and V2CTx/5Gr samples were 446 and 460 mAh g-1, respectively, with Coulombic efficiencies of 98.4 % and 98.8 %. These results indicate that the hybridization with carbon nanotubes and graphene resulted in minor changes in discharge capacity compared to V2CTx MXene. This study is anchored in its unique approach to synthesizing carbonaceous nanohybrids of V2CTx MXene, delving into their improved attributes, especially for application in Li-ion storage systems.