Feather-like etched Ti3AlC2 MAX phase as a redox mediated electrode for supercapacitor

Abstract

Ti₃AlC₂ has a layered structure, which is desirable in supercapacitor applications. However, due to the presence of Al layers, these layers disrupt the free movement of charges, causing the study of the efficient etching process of Ti₃AlC₂ to still receive continuous attention. Herein, a rapid microwave-assisted hydrothermal method has been introduced as an alternative etching method of Ti₃AlC₂. Moreover, the influence of different heating temperatures on the etching rate of Ti₃AlC₂ has been studied. The structural, morphology, surface elemental, and electrochemical analyses revealed that exposure to the Ti₃AlC₂ etching process under microwave radiation at a certain heating temperature resulted in a large crystallite size and a high number of defects which suppress the interaction between the electrolyte and electrode material. Among the synthesized samples, the etched Ti₃AlC₂ prepared at the temperature of 40 °C (T40) exhibited the highest specific capacity of 341 Cg⁻¹ at a current density of 0.8 Ag⁻¹. An asymmetric supercapacitor was assembled, and the device exhibited a specific capacitance of 40 Fg⁻¹ and retained 81 % of its initial specific capacitance after 5000 cycles.