Abstract:
This study presents a comprehensive methodology for the etching and delamination of carbide
(Mo₂TiC₂Tₓ) and carbonitride (Ti₃CNTₓ) MXenes, alongside protocols for the intercalation of
alkali and alkaline earth metal ions (Li⁺, Na⁺, K⁺, Mg²⁺) into these materials. Post-intercalation, the
resulting composites exhibit exceptional performance as supercapacitor electrode materials, with
K⁺-intercalated Ti₃CNTₓ demonstrating an ultra-high capacitance of 1530 F g⁻¹ and K⁺-intercalated
Mo₂TiC₂Tₓ achieving 698 F g⁻¹ at a scan rate of 2 mV s⁻¹. Moreover, the intercalation of cations
enhances charge storage kinetics by extending charge/discharge times and reducing solution
resistance and charge transfer impedance, indicative of improved ion transport pathways.
Structural analysis reveals a significant increase in the c-lattice parameter and interlayer d-spacing,
attributed to the effective accommodation of cations within the MXene framework. These findings
underscore the potential of cation intercalation for tailoring MXene properties, offering a pathway
for the design of advanced energy storage materials with remarkable electrochemical performance.
