Preparation of High-Purity V₂C MXene and Electrochemical Properties as Li-Ion Batteries

A novel high-purity V 2 C MXene two-dimensional carbide, was successfully synthesized by etching V 2 AlC with sodium fluoride and hydrochloric acid at 90°C for 72 h. From the analysis of X-ray diffraction, energy dispersive spectra, and X-ray photoelectron spectroscopy, the purity of as-synthesized V 2 C MXene was >90 wt% with a few impurities of Na 5 Al 3 F 14 and V 2 AlC. The V 2 C MXene made by this method was much purer than those made by HF etching at room temperature. The as-prepared V 2 C MXene showed excellent electrochemical properties as anode of lithium-ion batteries. The capacity can be 260 mAh g −1 if discharged under 370 mA g −1 . The capacity was increased with charge cycles at high charge rate (500 mA g −1 ). It was suggested that V 2 C with high purity can be promising anode material with excellent performance.