V_(2)C@MoS_(2)复合材料的制备及其储锂性能研究

Preparation and lithium storage performance of V_(2)C@MoS_(2) composite

由于较高的理论容量,二硫化钼(MoS_(2))是一种具有良好应用前景的锂离子电池负极材料;然而其也存在导电性较差和结构不稳定等问题。本文采用一步水热法将MoS_(2)原位生长在V_(2)C-MXene的表面,制备出了V_(2)C@MoS_(2)复合材料。利用XRD、SEM、TEM对制备的复合材料进行了结构表征,并采用循环伏安(CV)法、恒电流充放电法和交流阻抗法分析了该复合材料作为锂离子电池负极材料的电化学性能。结果表明,实验制得了结晶度良好的MoS_(2)纳米片,且均匀的负载在V_(2)C的表面;同时,掺杂的V_(2)C极大地提高了复合材料的导电性和结构稳定性,使V_(2)C@MoS_(2)作为锂离子电池负极材料表现出了优异的电化学性能,在50mA/g的电流密度下,循环50次后依然能保持524.4 mAh/g的可逆比容量,并且在1 A/g的大电流密度下,依然具有258.1 mAh/g的可逆比容量。

MoS_(2) is a potential lithium-ion battery anode material owing to its high theoretical capacity,but it also has some problems such as low electrical conductivity and poor structural stability.In the present study,V_(2)C@MoS_(2) composite is prepared by one-step hydrothermal method,during which MoS_(2) is in-situ grown onto the surface of V_(2)C-MXene.The structure of the V_(2)C@MoS_(2) is characterized by XRD,SEM and TEM,and the electrochemical performance of V_(2)C@MoS_(2) as anode material of lithium-ion battery is analyzed by CV curves,galvanostatic charge/discharge curves,and EIS plots.The results show that MoS_(2) nanoparticles are prepared with high crystallinity and they are uniformly loaded on the surface of V_(2)C.V_(2)C greatly improves the electrical conductivity and structural stability of the composite material.V_(2)C@MoS_(2) exhibits excellent electrochemical performance as anode material of lithium-ion battery.It retained a high reversible capacity of 524.4 mAh/g after 50 cycles at a current density of 50 mA/g,it can still deliver a capacity of 258.1 mAh/g and at a high current density of 1 A/g.