Exploring Bimetallic Solid Solution (Cr0.5V0.5)2AlC MAX Phase Synthesized in Open Atmosphere and its Electrochemical Characterization

MAX phases, layered ternary carbides and nitrides, possess high mechanical strength, ionic conductivity, thermal stability, electrical conductivity, and wear resistance, making them attractive for energy storage applications. Among them, bimetallic solid solution MAX phases, like (CrV) 2 AlC, offer enhanced tunability compared to single-metal counterparts. In this work, (Cr 0.5 V 0.5 ) 2 AlC was successfully synthesized at 1200°C in an open atmosphere using the modified molten salt shielded synthesis (MMS 3 ) method, followed by post-treatment with NaOH to selectively remove the secondary phases. The structural integrity and phase purity of the synthesized MAX phase were verified through X-ray diffraction (XRD) with Rietveld refinement, complemented by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A comprehensive electrochemical evaluation of the (Cr 0.5 V 0.5 ) 2 AlC MAX phase was carried out in acidic, basic, and neutral electrolytes, revealing its predominant pseudo-capacitive behavior in acidic electrolyte. These findings highlight the future promise of bimetallic MAX phases as tunable platforms for advanced supercapacitors and next-generation electrochemical devices.