Current microfabrication of micro‐supercapacitors often involves multistep processing and delicate lithography protocols. In this study, simple fabrication of an asymmetric MXene‐based micro‐supercapacitor that is flexible, binder‐free, and current‐collector‐free is reported. The interdigitated device architecture is fabricated using a custom‐made mask and a scalable spray coating technique onto a flexible, transparent substrate. The electrode materials are comprised of titanium carbide MXene (Ti3C2Tx) and reduced graphene oxide (rGO), which are both 2D layered materials that contribute to the fast ion diffusion in the interdigitated electrode architecture. This MXene‐based asymmetric micro‐supercapacitor operates at a 1 V voltage window, while retaining 97% of the initial capacitance after ten thousand cycles, and exhibits an energy density of 8.6 mW h cm−3 at a power density of 0.2 W cm−3. Further, these micro‐supercapacitors show a high level of flexibility during mechanical bending. Utilizing the ability of Ti3C2Tx‐MXene electrodes to operate at negative potentials in aqueous electrolytes, it is shown that using Ti3C2Tx as a negative electrode and rGO as a positive one in asymmetric architectures is a promising strategy for increasing both energy and power densities of micro‐supercapacitors.

Solution-processable two-dimensional (2D) materials offer the possibility of manufacturing heterostructures with various properties, creating a way to tune materials towards a specific application. Two different 2D materials, titanium carbide MXene (Ti 3 C 2 T x ) and reduced graphene oxide (rGO), have shown promising results for supercapacitor applications due to their flake-like morphology, high conductivity; and ability to intercalate molecules or ions for charge storage. Here, we demonstrate the self-assembly of a heterostructure between negatively charged Ti 3 C 2 T x and positively charged modified rGO after shear mixing. Changes in zeta (z) potential, X-ray diffraction (XRD) patterns; and Raman spectra confirm the assembly of this heterostructure. The produced rGO : Ti 3 C 2 T x heterostructures were used as electrodes for supercapacitors. The addition of rGO to Ti 3 C 2 T x allowed some widening of the voltage window. Moreover, due to the synergistic effect of these materials, an increase of the capacitance value was observed. An electrode film composed of rGO (1 wt.%) and Ti 3 C 2 T x (99 wt.%) achieved capacitance values up to 254 F · g À1 at 2 mV · s À1 and 193 F · g À1 at 100 mV · s À1 .[a] Dr.