Colloidal Synthesis and Defect Engineering of Vanadium Selenide: A High-Performance Anode Material for Li-Ion Batteries

Defect engineering is essential for enhancing the performance of lithium-ion batteries (LIBs), particularly in transition metal chalcogenides (TMCs). Vanadium selenide, known for its outstanding electrochemical performance, has been extensively studied. In this study, we successfully synthesized Mo-doped V₂Se₉ at the nano-scale using a liquid-phase process. The resulting Mo-doped V₂Se₉ anode enhances reactive sites, facilitates Li⁺ ion transport, and exhibits high electronic conductivity. With these advantages, a reversible capacity of 1309.45 mAh g^-1 at 100 mA g^-1 was confirmed even after the 100th cycle. Furthermore, Mo-doped V₂Se₉ exhibits non-anomalous behavior, demonstrating a 30.34% increase in capacity after 100 cycles compared to the initial cycle. Herein, we elucidate the variation in capacity with doping concentration and provide insights into the reasons for the capacity increase. This study presents an expandable strategy for synthesizing doped TMCs, contributing to the enhancement of the lithium-ion battery anode performance in other TMCs.