Synthesis Characterization and Electrochemical Performance of Nitrogen-Doped d-Ti3C2Tx/LiCoO2 Nanocomposite for Asymmetric Supercapacitor Applications

Ti 3 C 2 T x MXene, a two-dimensional transition metal carbide, has emerged as a promising pseudocapacitive material due to its high metallic conductivity, hydrophilic surface terminations, and abundant redox-active sites. When combined with LiCoO 2 , Ti 3 C 2 T x forms a hierarchically interconnected multilayered structure that facilitates efficient ion diffusion pathways, thereby enhancing charge storage kinetics. In this study, a nitrogen (N)-doped delaminated (d) Ti 3 C 2 T x /LiCoO 2 nanocomposite was successfully synthesized using a facile hydrothermal method. The resulting composite exhibits a layered architecture in which LiCoO 2 particles are uniformly distributed within the Ti 3 C 2 T x matrix. X-ray diffraction analysis confirms the structural phase of the N-doped d-Ti 3 C 2 T x /LiCoO 2 nanocomposite. Scanning electron microscopy reveals a well-defined multilayered morphology with LiCoO 2 particles intercalated between Ti 3 C 2 T x sheets, while transmission electron microscopy further confirms the formation of the N-doped d-Ti 3 C 2 T x /LiCoO 2 heterostructure. Electrochemical measurements demonstrate that the as-prepared electrode delivers a high specific capacity of 493.5 C g⁻¹ at a current density of 1 A g⁻¹ in 2 M KOH electrolyte. Moreover, the electrode exhibits excellent cycling stability, retaining 89.1% of its initial capacity after 8,000 cycles, with a coulombic efficiency of 94.3%. The slightly lower coulombic efficiency is attributed to irreversible faradaic reactions, partial dissolution or structural changes of the active material, and possible electrolyte-related side reactions during cycling. The fabricated symmetric supercapacitor device exhibited a specific capac ity of 33.01 C g⁻¹ at a current density of 1 A g⁻¹. The assembled ASC device (N-doped d-Ti 3 C 2 T x /LiCoO 2 //AC) achieved a maximum energy density of 10.31 Wh kg − 1 and a power density of 1119.06 W kg − 1 . These results highlight the synergistic interaction between Ti 3 C 2 T x and LiCoO 2 , providing an effective strategy for designing advanced electrode materials for high-performance energy storage applications.