Intertwined Titanium Carbide MXene within a 3 D Tangled Polypyrrole Nanowires Matrix for Enhanced Supercapacitor Performances

: The exploration of the rational design and synthesis of unique and robust architectured electrodes for the high capacitance, rate capability, and stability of supercapacitors is crucial to the future of energy storage technology. Herein, an in situ synthesis of multilayered titanium carbide MXene tightly caging within a 3 D conducting tangled polypyrrole (PPy) nanowire (NW) network is proposed as an effective strategy to prevent the aggregation of MXene, profoundly enhancing the electrochemical performance of the supercapacitor. Owing to the beneficial effects of an ideal 3 D interconnected porous structure and high electrical conductivity, the obtained electrode exhibits fast charge and ion transport kinetics as well as full usage of active material. As expected, the 3 D Ti3 C2 Tx @PPY NW exhibits a specific capacitance five times higher than that of pristine MXene (610 F g-1 ), a good rate capability up to a current density of 25 A g-1 , and excellent stability with 100 % retention after 14 000 cycles at 4 A g-1 , outperforming the known state-of-the-art MXene-based supercapacitor. Our work provides a facile method for enhancing the performance of MXene-based energy storage devices.