离子液体辅助水热合成1T-MoS_(2)及其锌离子储存性能

Ionic Liquid-assisted Hydrothermal Synthesis of 1T-MoS_(2)and Its Zinc Ion Storage Performance

采用离子液体辅助水热法,在碳布(CC)上合成了具有扩大层间距的1T-MoS_(2)纳米片阵列,对其结构形貌进行了表征,并研究了其锌离子储存性能.研究发现,作为水系锌离子电池正极材料,1T-MoS_(2)/CC在0.1 A/g电流密度下呈现出194.2 mA·h/g的放电比容量,且在1 A/g大电流密度下经750次循环后,仍可保持95.5%的容量保持率.1T-MoS_(2)/CC具有优异的锌离子储存性能可归因于:离子液体促进了1T相的形成,纳米阵列中的1T-MoS_(2)相含量约为78%,而高浓度1T相使其具有良好的电荷转移速率;离子液体插入1T-MoS_(2)层间使其层间距增至1.06 nm,可降低水合锌离子嵌入过程的能垒;碳布的三维结构可抑制MoS_(2)纳米片的聚集,从而促进了1T-MoS_(2)/CC与电解液间的充分接触.

A 1T-MoS_(2)nanosheets array with expanded interlayer spacing was synthesized on carbon cloth(CC)using an ionic liquid-assisted hydrothermal method.As a positive electrode material for zinc ion batteries,1T-MoS_(2)/CC exhibits a discharge specific capacity of 194.2 mA·h/g at 0.1 A/g current density,and can still maintain a capacity retention rate of 95.5%after 750 cycles at a high current density of 1 A/g.The excellent zinc ion storage capacity of 1T-MoS_(2)/CC can be attributed to:(1)ionic liquids promote the formation of 1T phase,with a 1T-MoS_(2)phase content of about 78%in the nanoarray,and a high concentration of 1T phase content gives it a good charge transfer rate;(2)the insertion of ionic liquids between 1T-MoS_(2)layers increases the interlayer spacing to 1.06 nm,which can reduce the energy barrier during the insertion process of hydrated zinc ions;(3)the three-dimensional structure of carbon cloth can inhibit the aggregation of MoS_(2)nanopages and promote sufficient contact between 1T-MoS_(2)/CC and electrolyte.