All-In-One MXene–Boron Nitride–MXene “OREO” with Vertically Aligned Channels for Flexible Structural Supercapacitor Design

Trends across various fields of energy storage technological advancement call for the development of materials to fulfill both functional and structural requirements. Flexible devices have been an evolutionarily progressive step in this area. Herein, Ti3C2Tx and hexagonal boron nitride (hBN) are used to build a flexible all-in-one Ti3C2Tx–hBN–Ti3C2Tx (THT) integrated composite film for a supercapacitor. The Ti3C2Tx layers function as active electrodes (with high electrical conductivity of 8100 S cm–1), while the hBN layer serves as the separator. This design streamlines the manufacturing of a robust supercapacitor, allowing the active materials to self-support and function independently from additional current collectors or binding agents. The THT film exhibits a Young’s modulus of 2.26 ± 0.03 GPa, reflecting the self-supporting nature of the film and suggests the reinforcement of the film by adding MXene layers adjacent to the hBN separator. Additionally, it exhibits high capacitance values of 0.20 F cm–2 at 50 mV s–1 and 225.60 F g–1 at 10 A g–1. A high power density of 209.2 mW cm–2 can be achieved at 700 mA cm–2 with an energy density of 5.6 μW h cm–2. This work highlights a design paradigm and offers a solution to accomplish roll-to-roll manufacturing for flexible energy storage devices.