Structural, electrical and electrochemical characterization of LiLa0.01Cr0.13Mn1.86O4 cathode material for lithium-ion battery

The LiLa0.01Cr0.13Mn1.86O4 cathode material is successfully synthesized by the solid-state reaction method. The X-ray diffraction (XRD) pattern reveals that the synthesized sample belongs to Fd3¯m space group with spinel structure. From the 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 LiLa0.01Cr0.13Mn1.86O4 obeys the Arrhenius principle with activation energy of 0.34 eV. The value of the real impedance Z′ 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′ 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, LiLa0.01Cr0.13Mn1.86O4 cathode is able to retain 95.1% of its initial capacity.