In this paper, we have synthesized the two-dimensional (2D) MXene layers and acid activated carbon (AAC) into a 3D conductive network structure, which could prevent the serious aggregation of 2D MXene layers. Two-dimensional MXene furnishes a new perspective and possibility to assemble flexible and conductive electrodes without any current collector, binders, or conductive additives when applied to energy storage devices. In the 3D conductive network architecture, the AAC particles are enclosed by the MXene flakes and enlarge the interlamellar spacing of MXene and considerably improve the electrochemical performance. The flexible MXene/AAC 2:1 electrode exhibits a high specific capacity (378 F g(-1) at 0.5 A g(-1)). Also, MXene/AAC 2:1 electrode shows an excellent capacitance retention (88.9% at 30 A g(-1)). In addition, the MXene/AAC compounds with different mass ratios used as positive electrodes and AAC used as the negative electrode to assemble asymmetrical supercapacitors exhibit exceptional electrochemical performances. The MXene/AAC 2:1//AAC achieves a high specific capacity (177 F g(-1) at 0.5 A g(-1)) and an excellent capacitance retention (97.4% retention after 10 000 cycles). Impressively, the 3D conductive network structure of MXene/AAC compounds achieved noteworthy adsorption capacity (311.5 mg/g) to remove methylene blue (MB).