Efficient electrophoretic deposition of MXene/reduced graphene oxide flexible electrodes for all-solid-state supercapacitors

MXene has been considered as a promising electrode materials for energy storage devices. This work reports using an electrophoresis effect to efficiently deposit Ti₃C₂T_x/rGO composite on flexible substrates, which are subsequently used as the electrodes of all-solid-state supercapacitors. The electrophoresis deposition does not require a binder in the fabrication of the Ti₃C₂T_x/rGO electrodes. The structures and properties of the MXene/graphene electrode materials are characterized using Zeta potential, scanning electronic microscope, X-ray powder diffraction, Fourier-transform infrared and X-ray photoelectron spectroscopy. The performance of the all-solid-state flexible supercapacitors are evaluated using cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy, and cycle life tests. The devices show high areal specific capacitance of ~12 mF cm⁻², small resistance, and excellent cycling stability at different current densities for over 4,000 cycles. Moreover, the all-solid-state flexible supercapacitors exhibit superior mechanical flexibility under different deformations.