Boosting the Capacitive Property of Ti₃C₂T_x MXene by Using Mechanochemical Activation Approach

We demonstrated a mechanochemically-assisted approach to synthesize Ti₃C₂T_x MXene with crinkled morphology with enhanced energy storage performance. The fabrication efficiency and capacitive property of the resulting Ti₃C₂T_x MXene was significantly promoted under the aid of a high-energy ball mill: (i) removal of Al from pristine Ti₃AlC₂ powder was achieved after 8 h of etching in 2% hydrochloric acid, while 18 h was sufficient in 5% hydrochloric acid for conventional experimental as reported in previous literature; (ii) the capacitive property of the as-prepared samples increases with etching time, the 8-h mechanochemically etched sample showed a specific capacitance of 129 F/g at 10 mV/s in 1 M H₂SO₄ electrolyte, while no typical energy storage behavior was found for the sample without mechanochemical aid. The contribution of double layer, pseudocapacitive and diffusion-limited capacitance for the total specific capacitance was quantitively analyzed for the first time. The as-prepared sample exhibits higher specific capacitance than the previously reported MXene and MXene-based composites. The mechanochemically-assisted approach showed good capability in preparing Ti₃C₂T_x MXene with enhanced capacitive property.