X-ray photoelectron and broadband impedance spectroscopy of Li_1+4<i>x</i>Ti_2-<i>x</i>(PO₄)₃ solid electrolyte ceramics

Abstract

Li 1+4x Ti 2-x (PO 4 ) 3 (where x = 0.2, 0.5) compounds were synthesized by solid state reaction, and ceramics were sintered. The structure of compounds was studied by X-ray diffraction. Elemental compositions and binding energies of Ti 2p, P 2p, O 1s, and Li 1s core level at the surfaces of Li 1+4x Ti 2-x (PO 4 ) 3 ceramics were determined by energy dispersive X-ray spectrometer (EDX) and X-ray photoelectron spectroscopy (XPS). Impedance spectroscopy of the ceramics was performed in the frequency range of 10 Hz-1 MHz by the four-electrode method and in the frequency range of 1 MHz -3 GHz by the microwave impedance spectrometer. The measurements of electrical properties of the ceramics were carried out in the temperature interval of (300-700) K. The increase of the stoichiometric factor x of the compounds leads to the increase of bulk conductivities and values of dielectric permittivity.

Synthesis and research of electrode and solid electrolyte materials for lithium ion batteries

“…The ionic radii of Li + and Ti 4+ are 0.92 Å and 0.74 Å, respectively. On the other hand, the analysis of XRD patterns shows the impurities of LiTiPO5 and Li 4 (P 2 O 7 ), which can also influence the above-mentioned parameters [14].…”