A novel MnO2/Ti3C2Tx MXene nanocomposite as high performance electrode materials for flexible supercapacitors.

Abstract MnO 2 is considered as one of the most promising electrode materials for flexible supercapacitors but it often suffer in poor conductivity, which limits practical applications according to industry needs. To enhance the performance, forming MnO 2 -based hybrid structures with conductive materials is a promising implement approach. Ti 3 C 2 T x MXene sheets, a new kind of 2D transition metal carbides with metallic conductivity and hydrophilic nature, are promising candidate to couple with MnO 2. According to the complementary principle, we design a novel structure MnO 2 /Ti 3 C 2 T x hybrid nanocomposite by synergistically coupling one-dimensional (1D) MnO 2 nanoneedles with two-dimensional (2D) Ti 3 C 2 T x MXene sheet for flexible supercapacitor. XPS investigations suggest the obvious charge transfer from Ti 3 C 2 T x sheets to MnO 2 nanoneedles, where Ti 3 C 2 T x sheets serve as a remarkable 2D conductive substrate to facilitate the electrons transfer in the nanocomposites. This strong synergistic effect between Ti 3 C 2 T x and MnO 2 resulting from the chemical interaction greatly enhance the electrical conductivity, specific capacitance, rate stability and structural stability of the MnO 2 /Ti 3 C 2 T x nanocomposite. To show the potential application in energy storage, a symmetrical flexible supercapacitor device with good electrochemical performance, high flexibility and super cycling ability is fabricated by utilizing MnO 2 /Ti 3 C 2 T x nanocomposites as electrode materials. This work has proposed a new approach of developing advanced nanocomposites from a MnO 2 -based electrode for high performance flexible electronics. Graphical abstract In this work, we design a novel structure MnO 2 /Ti 3 C 2 T x hybrid nanocomposite by synergistically coupling one-dimensional (1D) MnO 2 nanoneedles with two-dimensional (2D) Ti 3 C 2 T x MXene sheet for flexible supercapacitor. Notably, 2D Ti 3 C 2 Tx sheets in the nanocomposite serve as a remarkable 2D conducive substrate to facilitate electrons transfer, which enhance the specific capacitance and cycle ability of the supercapacitor. Image 1 Highlights • MnO 2 /Ti 3 C 2 T x nanocomposite was succesfully achieved. • Ti 3 C 2 Tx sheets serve as a remarkable 2D conducive substrate to facilitate electrons transfer. • The synergistic effect between MnO 2 and Ti 3 C 2 T x is significantly affected by the MnO 2 content. • The flexible supercapacitor shows outstanding cycling stability. [ABSTRACT FROM AUTHOR]