Fluorinated Transition Metal Carbides for Flexible Supercapacitors

Abstract

The mixed, hexagonal, layered carbides and nitrides known as the MAX phases are utilized in diverse electrochemical devices, in similar ways as graphite is used. Fluorinated graphite shows significantly improved electrochemical energy storage performance when compared to graphite, and while the carbides MAX phases are extensively studied, fluorine-doped MAX phases are yet to be examined. Herein, a series of fluorinated MAX phase materials suitable as a viable electrode material for flexible supercapacitors (FSCs) were prepared by using a fluorination route. The insertion of fluorine as a heteroatom into the MAX phase structures leads to a significant improvement of their structural, wettability, and electrochemical properties. Various electrochemical and morphological characterizations were performed to investigate the influence of various metal (M) elements (e.g., Ti, Ta, V, Cr, and Mo) on the fluorinated MAX phase electrodes. Moreover, the electrochemical outcomes demonstrate that the fluorinated materials effectively increase the capacitance and power density of the electrodes, and the fundamental concepts are established. As a proof concept, supremely FSCs were utilized as a portable power source for powering a digital timer.