Enhanced microwave sintering characteristics, electrical and thermal properties of nano Li2TiO3 ceramic and its nanocomposite using LiNi0.5Co0.5PO4 as high-capacity cathode for Li-ion batteries

Abstract

Abstract Microwave sintering drastically reduces the lattice distortion, strain that developed by ball milling and enhances Li-ion mobility highly beneficial for Li-ion batteries. In the present study, we have explored the preparation of nanocrystalline Li 2 TiO 3 with monoclinic structure using high energy ball milling followed by calcination at 700\u202f°C for 2\u202fh. Samples are microwave sintered at different temperatures and their X-ray diffraction pattern reveals the transformation of β → γ phase. The scanning electron microscopy studies confirm the well crystalline nature and average particles size in range of 20–40\u202fnm. High-resolution transmission electron microscopy, Raman and Fourier transform infrared spectroscopic studies reveal that Li-ion migration occurs from tetrahedral site to octahedral site along c-direction, parallel to a-b plane. The specific heat, thermal diffusivity, conductivity measurements are performed in the temperature range of 30–800\u202f°C. There is a significant improvement of alternating current conductivities (in the order of 10 −3 \u202fS/cm) and low activation energies in the range of 0.1–0.38\u202feV. Electrochemical characteristics of microwave sintered Li 2 TiO 3 incorporated Li 2 TiO 3 .LiNi 0.5 C 0.5 PO 4 nano-composite shows specific capacity of 148.42 mAhg −1 with 99% retention at 50 cycles. Impedance spectroscopy reveals that the charge transfer resistance of Li 2 TiO 3 .LiNi 0.5 C 0.5 PO 4 and LiNi 0.5 C 0.5 PO 4 are 27.5 and 253\u202fΩ, respectively.