Self-assembled three-dimensional Ti_3C_2T_x nanosheets network on carbon cloth as flexible electrode for supercapacitors

摘要

In recent year, flexible energy storage materials have attracted extensive attention in portable and wearable devices. MXenes, a new family of two-dimensional material, which exhibits excellent energy storage properties, has been widely used in flexible energy storage system. In this investigation, a Ti3C2Tx/CC (Carbon cloth) flexible electrode is successfully synthesized by a simple method of dipping and fast freezing. The results indicate that the prepared electrode shows a areal capacitance of 191 mF.cm(-2) at current density of 1 mA.cm(-2) and it could be increased to 312 mF.cm(-2) by further surface treatment (obtaining ak-Ti3C2Tx/CC electrode). Furthermore, it exhibits a 97% capacitance retention at a current density 4 mA.cm(-2) after 8000 charge-discharge cycles. The excellent electrochemical performance can be explained by the open three-dimensional network structure of self-assembled Ti3C2Tx nanosheets. This unique structure effectively enhances the access of electrolyte ions and facilitates the fast electron transfer during charge and discharge processes. The electrode is characterized by low cost, simple preparation, high flexibility and unique open network structure, which is expected to be used as flexible substrate to produce high-performance flexible electrode by combining with other materials such as oxides and conducing polymers.