Synergistic Improvements in Ionic Conductivity, Diffusion Dynamics, and Transference Numbers for LaNiO3/MXene Supercapacitor Electrodes

In this study, MXene (Ti3C2Tx) at varying concentrations (0, 10, 20, and 30%) was incorporated into perovskite‐based LaNiO3 (PLNO) using a solvothermal synthesis approach. X‐ray diffraction confirmed the simple cubic phase of the sample series. Braunauer Emmet Teller analysis and field emission scanning electron microscopy revealed that all samples exhibited a mesoporous structure and reduced grain size, likely due to the MXene inclusion, which enhanced the electrochemical response. Energy dispersive spectroscopy confirmed that the elemental composition of the samples matched the expected stoichiometric ratios. Electrochemical testing using cyclic voltammetry showed that the samples exhibited battery‐type behavior, with LNO‐III‐material achieving the highest capacity of 541.60 C/g at a scan rate of 2.5 mV/s. Galvanostatic charge/discharge analysis indicated that the discharge time increased with MXene content, and the Ragone plot showed impressive energy and power densities of approximately 84.30 Wh/kg and 2125 W/kg at 2.5 A/g, respectively, along with exceptional cyclability of 98% retention over 2000 cycles. Electrochemical impedance spectroscopy further revealed low charge transfer resistance (0.84 Ω), a short relaxation time (17 ms), high diffusion rate (1.06 m2/s), good ionic conductivity (6.3×10‐3 S/cm), and a transference number (t+) of 0.3, demonstrating the potential of the optimized electrode material for supercapacitor applications.