Enhanced Electrochemical Performance of Lanthanum-Doped Li4Ti5O12 Nanoflakes Synthesized via Hydrothermal Route for Supercapacitor Applications

In material research, heteroatom doping in a host lattice is regarded as an effective method to modify the structural and electronic properties of the materials, consequently enhancing their electrochemical performance. This study represents the microstructural and electrochemical properties of lanthanum-doped Li4Ti5O12 (Li4Ti5−xLaxO12, x = 0.02, 0.04, and 0.06) using a hydrothermal method. The findings indicate that all three compositions demonstrate a comparable crystallite phase, free from discernible impurities, and exhibit a flake-like morphology. The Li4Ti4.96La0.04O12 sample exhibited a cubic spinel structure with flake-like morphology, a low crystallite size of 9.7 nm and a reasonably good electrical conductivity of 3.56 × 10−6 S cm−1. In order to delve deeper into the supercapacitive behavior, the electrochemical characteristics of the electrodes were assessed through cycling voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). Notably, the Li4Ti4.96La0.04O12 electrode demonstrated exceptional electrochemical performance, achieving a specific capacitance of 461 F g−1 at 1 A g−1. Furthermore, it exhibited commendable cycling stability with approximately 80% capacitance retention after 5000 cycles and around 89% Coulombic efficiency, highlighting its potential as a noteworthy electrode material for energy storage applications.