Structure, dielectric, and temperature-dependent conductivity studies of the Li2FeSiO4/C nano cathode material for lithium-ion batteries

摘要

The electrical conductivity plays a vital role in the enhancement of the electrochemical performance of Li2FeSiO4 type systems. In most of the system, the elevated temperature operation creates severe structural re-orientation, which cause thermal runway in LIBs. Hence, the exploration of the impacts of temperature on the electrical properties of Li2FeSiO4 nano cathode can emphasize to optimize the operating temperature for the LIBs. The lithium-ion diffusion kinetics on the Li2FeSiO4/C at different temperatures (-5 to 400 degrees C) has been investigated. Rietveld refinement of the XRD data ensured that the Li2FeSiO4/C possess an orthorhombic structure with Pmn2(1) space group. The FE-SEM and TEM micrographs display the spherical morphology of the nanoparticles with an average particle size of 25nm. The single-phase formation and presence of carbon have been elucidated by FTIR, Raman, and XPS analysis. The Li2FeSiO4/C exhibits an excellent electrical conductivity of 1.022x10(-4) Scm(-1) at room temperature. The electrochemical reversibility of the Li2FeSiO4/C cathode in an aqueous electrolyte has been explored by cyclic voltammetry (CV) analysis. The Li2FeSiO4/C nano cathode exhibits excellent electrical properties at the elevated temperatures (from 50 to 125 degrees C) which can be optimized to perform stable operation of the all solid-state lithium-ion batteries.