MXene‐Derived TiO2/Starbon Nanocomposite as a Remarkable Electrode Material for Coin‐Cell Symmetric Supercapacitor

Abstract In this study, the synthesis of a MXene (Ti 3 C 2 T x )‐derived TiO 2 /starbon (M‐TiO 2 /Starbon‐800 °C) nanocomposite using a facile calcination method is explored. High‐temperature exposure transforms layered Ti 3 C 2 T x into rod‐like TiO 2 and starbon into amorphous carbon. The resulting M‐TiO 2 /Starbon‐800 °C nanocomposite exhibits a significantly larger surface area and pore volume compared to its individual components, leading to superior electrochemical performance. In a three‐electrode configuration, the nanocomposite achieved a specific capacitance (C sp ) of 1352 Fg⁻¹ at 1 Ag⁻¹, while retaining more than 99% of its C sp after 50 000 charge/discharge cycles. Furthermore, when incorporated into a two‐electrode symmetric coin cell, it demonstrates a C sp of 115 Fg⁻¹ along with exceptional long cycle life. Moreover, the device shows an energy density (ED) of 51 Whkg −1 and a power density (PD) of 7912 Wkg −1 at 5 Ag −1 . The enhanced charge storage is attributed to the formation of a porous structure with a high specific surface area resulting from the interaction between M‐TiO 2 nanorods and starbon, which facilitates efficient ion penetration.