Structural, dielectric, optical, and electrochemical performance of Li4Mo5O17 for ULTCC applications

Abstract

Lithium molybdates are of great interest in ultra-low temperature cofired ceramics (ULTCC) technology due to their low processing temperature. In this study, a ULTCC Li4Mo5O17 was prepared via a solid state route. X-ray diffraction and Raman spectroscopy analysis revealed the formation of single phase triclinic structure. The variation in relative permittivity and dielectric loss of the sample with the change in frequency is explained using the polaron model. At the excitation of 514 nm, excitonic and deep-level (impurities, oxygen, and lithium vacancies) emissions were observed which contribute to the lossy nature of Li4Mo5O17. The experimentally calculated direct optical band gap energy of ∼ 3.1 eV is consistent with the energy gap (∼ 3.07 eV) predicted through density functional theory. The electrochemical study showed that the sample exhibits a high specific capacitance of ∼ 252.5 F/g at a low scan rate of 5 mV/s.