Synthesis and lithium ion storage performance of novel two dimensional vanadium niobium carbide (VNbCTx) MXene

Two-dimensional double transition metal carbides/nitride with unique out-of-plane arrangement of two metal atoms is emerging as a new pseudocapacitor material and attracting wide attention in the field of energy storage. Herein, fabrication of a novel 211-phase vanadium niobium carbide (VNbCTx) MXene by selectively etching the Al atomic layer from its VNbAlC MAX phase is reported for the first time. Effect of etching parameters on the microstructure, crystallinity, and electrochemical property of multilayer VNbCTx is examined. As the electrode material of lithium ion batteries, VNbCTx show a higher specific capacity of 520.5 mAh g−1 at 0.1 A g−1 and promising cycle stability. This work provides additional understanding about the synthesis and storage performance of double transition metal MXene, which will benefit the development of novel double transition metal MXene for energy storage applications.