Preparation of high-purity V₂C MXene and electrochemical properties as li-ion batteries

A novel high-purity V₂C MXene two-dimensional carbide, was successfully synthesized by etching V₂AlC 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 V₂C MXene was >90 wt% with a few impurities of Na₅Al₃F₁₄ and V₂AlC. The V₂C MXene made by this method was much purer than those made by HF etching at room temperature. The as-prepared V₂C 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 V₂C with high purity can be promising anode material with excellent performance.