Molten salt-shielded synthesis of Ti3AlC2 as a precursor for large-scale preparation of Ti3C2Tx MXene binder-free film electrode supercapacitors

Abstract

MXenes are a group of two-dimensional materials that are promising for many applications, including as film electrode supercapacitors. When synthesizing such materials, special attention is paid to the conditions for obtaining the MAX phase, the chemical, morphological and structural features of which determine the functional properties of the final product. In this study, the Ti₃AlC₂ precursor is proposed to be obtained using a technologically simple and accessible method of synthesis in molten salt. This method allows reducing the reaction temperature and creating an antioxidant atmosphere. Ti₃C₂T_x MXene electrode films are produced by the easily scalable blade coating method without a binder. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy. Electrochemical testing of Ti₃C₂T_x film electrodes was carried out in a three-electrode configuration in aqueous solutions of 1M H₂SO₄, 6M KOH, 1M LiOH and 1M Na₂SO₄ electrolytes. The maximum specific capacity value for Ti₃C₂T_x MXene binder-free film electrode supercapacitors is obtained in 1M H₂SO₄ electrolyte (480 F g⁻¹ at a scan rate of 1 mV s⁻¹). The simple, low-cost and scalable production technology and promising electrochemical characteristics of the Ti₃C₂T_x MXene binder-free film electrode make it an excellent candidate for new-generation supercapacitors.