The self-stacking and collapsing of few-layered Ti3C2Tx(d-Ti3C2Tx) results in its poor rate capability and cycle performance during charge/discharge processes. Constructing a three-dementional (3D) structure, introducing interlayer spacers and using alkaline electrolytes are effective and powerful strategies to resolve the problems. Herein, a 3D crumpled d-Ti3C2Tx/PANI composite was successfully prepared by HCl/LiF in-situ etching Ti3AlC2 to obtain d-Ti3C2Tx and polymerizing PANI onto its surface with ice-bath stirring. Benefiting from the synergistic effect of kinetically favorable structure, component and alkaline electrolytes, The PM-1 (d-Ti3C2Tx/PANI-1) as an electrode remarkably improves the electrochemical performances compared with the original d-Ti3C2Tx in 2 M KOH electrolyte. It exhibits a specific capacitance of 230 mF cm−2（115 F g−1）at 2 mA cm−2, high rate capability of 81.2% at 20 mA cm−2 and outstanding stability of 96.7% retention after 5000 cycles at 10 mA cm−2. Furthermore, an assembled symmetric supercapacitor (SSC) also presents an excellent stability performance with 82.4% retention after 5000 cycles at 8 mA cm−2 and a promising energy storage performance. The related work provides a good reference for the MXene-based electrode materials in the conditions of alkaline electrolytes. © 2024 Elsevier Ltd