The aqueous hybrid supercapacitor (AHSC) based on ammonium ion (NH₄⁺) is an interesting energy storage device with excellent properties. However, the scarcity of appropriate and effective cathode materials limited its practicality. Two-dimensional (2D) transition metal nitrides, carbides, and/or carbonitrides (MXenes) show potential as cathode materials, but their low capacitance also limits their applicability. Here, we synthesized N-functionalized 2D MXene (Ti₃C₂T_x) with Ti₂N interface engineering (Ti₂N/Ti₃C₂T_x), which displayed not only superior capacitance and rate capability but also a cycling stability then pristine Ti₃C₂T_x. Ex-situ XRD and XPS were used to study the fast transport of electrons/ions and its charge storage mechanism at the interface of Ti₂N/Ti₃C₂T_x. Furthermore, density functional theory (DFT) calculations were employed to validate the superior conductivity at the interface of the Ti₂N/Ti₃C₂T_x(T_x = OH) electrode. Moreover, AHSC was assembled with the Ti₂N/Ti₃C₂T_x as cathode and activated carbon as anode possesses outstanding energy storage performance. This study not only elucidates the charge storage process of Ti₂N/Ti₃C₂T_x but also provide new insights for designing novel cathode materials for energy storage devices.