Structural, Electrical and Electrochemical Characterization of LiLa_0.01Cr_0.13Mn_1.86O₄ Cathode Material for Lithium-ion Battery

Abstract

The LiLa_0.01Cr_0.13Mn_1.86O₄ cathode material is successfully synthesized by solid-state reaction method. The X-ray diffraction (XRD) pattern reveals that the synthesized sample belongs to Fd$\overline{3}$m space group with spinel structure. From FT-IR study of the material, two distinct strong absorption peaks are detected. From the electrical properties studies, it is found that the bulk conductivity of LiLa_0.01Cr_0.13Mn_1.86O₄ obeys Arrhenius principle with activation energy of 0.34 eV. The value of the real impedanceZ′$Z\prime$decreases at lower frequency with increasing temperature, indicating the negative temperature coefficient of resistance (NTCR) type behavior of the sample. The variation of the bulk resistance and dc conductivity as a function of temperature, and the variation of the ac conductivity and the real dielectric constant ε′$\epsilon \prime$as a function of frequency are also reported. The charge/discharge curves show two plateaus with initial discharge capacity of 107.6 mAh g⁻¹. After 15 cycles, LiLa_0.01Cr_0.13Mn_1.86O₄ cathode is able to retain 95.1% of its initial capacity.