Synthesis of ordered double transition metal Ti2NbAlC2 MAX phase and investigation of energy storage properties of Ti2NbC2Tx MXene

This doctoral thesis focuses on the synthesis, structural characterization, and production of MXene materials derived from MAX phases. In this study, the ordered Ti₂NbAlC₂ MAX phase was synthesized via a high-temperature solid-state reaction, followed by chemical etching to obtain multilayered and few-layer Ti₂NbC₂Tₓ MXene structures. The synthesized materials were characterized using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM), and Raman spectroscopy. The electrochemical performance of the MXene electrodes was evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Ti₂NbC₂Tₓ MXene exhibited specific capacitances of 322 and 642 F g⁻¹ at a current density of 0.5 A g⁻¹ in Na₂SO₄ and H₂SO₄ electrolytes, respectively, while retaining 95% and 100% of its initial capacitance after 10,000 cycles. Furthermore, asymmetric supercapacitors fabricated using Ti₂NbC₂Tₓ MXene and activated carbon achieved energy densities of 31.1 and 34.0 Wh kg⁻¹ in PVA-Na and PVA-H gel electrolytes, respectively. The results demonstrate that controlled MAX phase synthesis plays a crucial role in determining MXene quality and electrochemical performance, highlighting Ti₂NbC₂Tₓ MXene as a promising electrode material for next-generation energy storage systems.