Optical, magnetic, thermodynamic, and dielectric studies of the disordered rock salt Li1.3Nb0.3Fe0.4O2 cathode for Li-ion batteries

Abstract

While most studies in disordered rock salt cathode materials focus on synthesis and electrochemical investigation, detailed investigations on their optical and thermodynamic properties are a matter of interest. Here, we report on complementary measurements of transient absorption spectroscopy, thermodynamic, and dielectric properties for Li1.3Nb0.3Fe0.4O2 (LNFO) disordered rock salt Li-excess. The structure was studied using powder x-ray diffraction and scanning electron microscopy, which showed the fine crystallization of LNFO. The ultra-fast laser spectroscopy is used to study the dynamics of charge carriers and electron–phonon coupling in the system. Our thermodynamic measurements have revealed a magnetically ordered phase with small spontaneous magnetization. The dielectric properties of LNFO illustrate high permittivity with losses at low frequencies. Furthermore, the behavior of the dielectric modulus and AC conductivity vs temperature and frequency were discussed.

Thermal and dielectric properties of disordered rocksalt Li-excess Li1.3Nb0.3Mn0.4O2 cathode material for lithium-ion batteries

“…The dielectric measurements are considered a potent tool to study the dynamic properties of the sample such as conductance, permittivity, and loss factor [35,36]. Through the dielectric properties, we can obtain some information about the grain and grain boundaries of the studied compound and its structure [37].…”