二维层状Ti3C2Tx-MXene@VS2用于高性能锂离子电池负极

为探索一种高性能的锂离子电池负极材料，采用酸刻蚀法制备了高导电性、高稳定性的二维层状Ti₃C₂T_x，通过溶剂热法制备了具有高理论比容量的花瓣状VS₂纳米片，再经过简单的液相混合得到了二维层状Ti₃C₂T_x-MXene@VS₂复合物。通过扫描电子显微镜、透射电子显微镜、X射线光电子能谱、X射线衍射和能谱分析对复合材料的形貌和结构进行了表征，采用循环伏安、恒流充放电、长循环和交流阻抗谱对复合材料的电化学性能进行了研究。结果表明：VS₂纳米片均匀地分布在Ti₃C₂T_x的层间及表面，该复合物具有高的可逆容量(电流密度为0.1A·g^-1时，比容量为610.5mAh·g^-1)、良好的倍率性能(电流密度为2A·g^-1时，比容量为197.1mAh·g^-1)和良好的循环稳定性(电流密度为0.2 A·g^-1时，循环600圈后比容量为874.9 mAh·g^-1；电流密度为2 A·g^-1时，循环1 500圈后比容量为115.9mAh·g^-1)。

2D-Layered Ti3C2Tx-MXene@VS2 as Anodes for High-Performance Lithium-Ion Batteries

To explore a high-performance anode for lithium-ion batteries, 2D-layered Ti₃C₂T_x with high conductivity and stability was prepared by acid etching, and petal-shaped VS₂ nanosheets with high theoretical specific capacity were prepared by solvothermal method. Then the 2D-layered Ti₃C₂T_x-MXene@VS₂ hybrid was obtained by a simple liquid-phase mixing method. The morphology and structure of this hybrid were systematically characterized by scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, X-ray diffraction, and energy-dispersive X-ray diffraction, while the electrochemical properties were studied by cyclic voltammetry, galvanostatic charge/discharge, long cycle life, and AC impedance spectroscopy. The results indicate that VS₂ nanosheets are uniformly distributed between the layers and on the surface of Ti₃C₂T_x. The hybrid had a high reversible capacity (610.5 mAh·g^-1 at 0.1 A·g^-1), good rate performance (197.1 mAh·g^-1 at 2 A·g^-1), and good cycle stability (874.9 mAh·g^-1 at 0.2 A·g^-1 after 600 cycles; 115.9 mAh·g^-1 at 2 A·g^-1 after 1 500 cycles).