Enhanced electrochemical performance of MgFe2O4/SrTiO3 and MgFe2O4/ SiO2 nanocomposite structures

MgFe2O4/SrTiO(3 )and MgFe2O4/SiO2 nanocomposites were prepared via a modified sol-gel auto combustion method. X-ray diffraction (XRD) patterns confirmed the formation of both MgFe2O4/SrTiO3 and MgFe2O4/ SiO2 nanocomposite structures. Williamson-Hall analyses showed that MgFe2O4/SrTiO3 had a crystallite size of 18 nm, while it was 17 nm for MgFe2O4/SiO2. It was found that the lattice constant for MgFe2O4/SiO2 was longer than that for MgFe2O4/SrTiO3; thus, the cell volume was larger for MgFe2O4/SiO2 nanocomposite. Fourier transform infrared (FTIR) spectra for MgFe2O4/SrTiO3 and MgFe2O4/SiO2 nanocomposites revealed absorption bands corresponding to bending vibrations of the TiO6 octahedron and Si?O?Si with symmetric and antisymmetric stretching vibrations. The electrochemical characteristics showed that MgFe2O4/SrTiO3 and MgFe2O4/SiO2 nanocomposites exhibited similar initial discharge capacity values, while MgFe2O4/SrTiO3 had a higher coulombic efficiency of 64.1%. After 100 cycles, MgFe2O4/SrTiO3 de-livered a discharge capacity of 311 mAh g(-1), larger than MgFe2O4/SiO2. Furthermore, MgFe2O4/SrTiO3 na-nocomposite demonstrated significantly improved high rate capability, with a capacity of 330 mAh g(-1) and 65% retention of the 2nd cycle, compared to MgFe2O4/SiO2 (with a capacity of 252 mAh g-(1) and 42% re-tention of the 2nd cycle) after the current density was returned to 100 mA g(-1). (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

MgFe2O4/SrTiO3 and MgFe2O4/SiO2 nanocomposites were prepared by a modified sol-gel auto combustion method. The structures and properties of the composites were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The electrochemical tests showed that MgFe2O4/SrTiO3 nanocomposite had higher coulombic efficiency and larger discharge capacity, and exhibited better stability and capacity retention in high-rate performance.