Dielectric studies and conduction mechanism of Zn and Ag modified LiMn2O4 synthesized by solution combustion method

Pugazhendhi, Anbarasi; Ellappan, Satheeshkumar; Kumaresan, Ilango; Paramasivam, Manohar

doi:10.1007/s00339-017-1021-3

Cited by 10 publications

(1 citation statement)

References 47 publications

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“…At low frequency, the polarization of small-polaron hopping and localized transport of Li ions can be synchronized with the sharp variation of the alternating electric field. At mid-frequency and high-frequency stages, the polarization of localized transport of Li ions and small polarons cannot be synchronized with the periodic variation of the alternating electric field, resulting in the decline in values of dielectric permittivity and becoming a constant at higher frequency. ,,− In addition, as temperature increases, ε′ gradually increases, which indicates the thermally activated process.…”

Section: Resultsmentioning

confidence: 99%

Long-Range and Short-Range Transport Dynamics of Li Ions in LiMn₂O₄

Zheng

Wang

et al. 2020

J. Phys. Chem. C

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Investigation of lithium ion transport between different crystallographic sites in different phase structures has been regarded as a challenging diffraction issue. In this work, isothermal dielectric spectroscopy and the electric modulus of LiMn 2 O 4 (LMO) were adopted to reveal Li-ion transport behavior. Dielectric and electric modulus spectra show three thermally activated processes: (i) enhanced mid-frequency dielectric permittivity above 133 K contributed by the short-range migration of Li ions, (ii) high-frequency dielectric relaxation associated with hopping of small polarons, and (iii) low-frequency giant dielectric loss (dc conductivity) caused by the long-range migration of Li ions at high temperature. In addition, an obvious change of dielectric permittivity around 280 K happens at structural transition from cubic to tetragonal of LMO. Furthermore, it was found that the short-range mobility of Li ions and hopping of small polarons lead to the variation of β in the Kohlrausch−Williams−Watts (KWW) function of the electric modulus. Thus, our work provides a revealing insight into the electrical transport mechanism and migration dynamics of Li ions in LMO.

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