Akademik Veri Yönetim Sistemi
Energy Technology, cilt.14, sa.4, 2026 (SCI-Expanded, Scopus)
In this study, Li4-x/3Ti5−2x/3SmxO12 (x = 0, 0.01, 0.05, 0.10) compounds were synthesized via a facile and cost-effective solid-state reaction method to investigate their structural, photoluminescent, electrochemical, and supercapacitive properties. X-ray diffraction (XRD) analysis confirmed that Sm3+ ions were successfully incorporated into the Li4Ti5O12 (LTO) spinel lattice without altering the crystal structure, indicating high phase purity and structural stability upon doping. Scanning electron microscopy (SEM) revealed homogeneous particle morphology with subtle changes in grain size, while BET surface area analysis provided insights into surface area variations due to Sm3+ substitution. Raman spectroscopy further verified the integrity of the spinel framework and highlighted lattice distortions associated with dopant incorporation. Photoluminescence (PL) spectroscopy showed that both undoped and Sm3+-doped LTO samples exhibit broad emission bands in the 600–850 nm range, primarily attributed to intrinsic oxygen vacancy-related defect states. Notably, Sm3+ doping enhanced the emission intensity by approximately 30%, demonstrating its effectiveness in promoting radiative recombination processes relevant for optical applications such as white light-emitting diodes (W-LEDs). Electrochemical evaluations, including galvanostatic charge–discharge (GCD) and cyclic voltammetry (CV) measurements, revealed that Sm3+ incorporation improved lithium-ion diffusion kinetics and electronic conductivity, resulting in enhanced reversible capacity and rate capability. Furthermore, supercapacitor performance was assessed through capacitance measurements at various current densities. The Sm-doped LTO exhibited high specific capacitances of 325.58 F/g at 1 A/g (C1), decreasing gradually to 222.69 F/g at 20 A/g (C20), demonstrating excellent rate capability. The cyclic stability test at 20 A/g showed a capacity retention consistent with high durability. CV profiles recorded at 0/0.65 V and GCD curves at 0/0.52 V confirmed stable electrochemical behavior under operational conditions. These combined results highlight the dual-functional role of Sm3+ doping in simultaneously tuning optical emission and electrochemical properties, while also providing promising supercapacitive performance. The synergistic enhancement underscores the potential of Sm3+-doped Li4Ti5O12 as a multifunctional material for integrated photonic and energy storage applications, including next-generation W-LEDs, lithium-ion batteries, and high-performance supercapacitors. Formun Üstü. Formun Altı.