RESUMO
In this study, we synthesize nanostructured NdMnxFe1-xO3 perovskites using a facile method to produce materials for the high-working-efficiency anodes of Li-ion batteries. A series of characterization assessments (e.g., X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electron microscopy) were conducted, and the results confirmed the efficacious partial replacement of Fe ions with Mn ions in the NdFeO3 perovskite structure, occurrence of both amorphous and crystalline structures, presence of oxygen vacancies (VO), and interconnection between nanoparticles. The possibility of Mn ion replacement significantly affects the size, amount of VO, and ratio of amorphous phase in NdMnxFe1-xO3 perovskites. The NdMnxFe1-xO3 perovskite with x = 0.3 presents a notable electrochemical performance, including low charge transfer resistance, durable Coulombic efficiency, first-rate capacity reservation, high pseudo-behavior, and elongated 150-cycle service life, whereas no discernible capacity deterioration is observed. The reversible capacity of the anode after the 150th-cylcle was 713 mAh g-1, which represents a high-capacity value. The outstanding electrochemical efficiency resulted from the optimum presence of VO, interconnection between the nanoparticles, and distinctive properties of the NdFeO3 perovskite. The interconnection between nanoparticles was advantageous for forming a large electrolyte-electrode contact area, improving Li-ion diffusion rates, and enhancing pseudocapacitive effect. The attributes of perovskite crystals, coexistence of Mn and Fe throughout the charge/discharge process, and optimum VO precluded the electrode devastation that caused the Li2O-phase decomposition catalysis, enabling favorable reversible Li storage.
RESUMO
In this work, single-phase nanostructured NdFe1-xCoxO3 (x = 0, 0.1, 0.2, and 0.3) perovskite materials were obtained by annealing stoichiochemistry mixtures of their component hydroxides at 750 °C for 60 min. The partial substitution of Fe by Co in the NdFeO3 crystal lattice leads to significant changes in the structural characteristics, and as a consequence, also alters both the magnetic and optical properties of the resulting perovskites. The low optical band gap (Eg = 2.06 ÷ 1.46 eV) and high coercivity (Hc = 136.76 ÷ 416.06 Oe) give Co-doped NdFeO3 nanoparticles a huge advantage for application in both photocatalysis and hard magnetic devices.