Electrochemical performance of Li-rich oxide composite material coated with Li0.75La0.42TiO3 ionic conductor

Abstract

Li-rich (spray-dried (SP)-Li1.2Ni0.2Mn0.60O2) composite materials were prepared via two-step ball-mill and spray dry methods by using LiOH, α-MnO2, β-Ni(OH)2 raw materials. Two raw materials of α-MnO2 nanowires and microsphere β-Ni(OH)2 were synthesized by a hydrothermal process. In addition, Li0.75La0.42TiO3 (LLTO) fast ionic conductor was coated on SP-Li1.2Ni0.2Mn0.60O2 composite via a sol–gel method. The properties of the LLTO-coated SP-Li1.2Ni0.2Mn0.60O2 composites were determined by X-ray diffraction, scanning electron microscopy, micro-Raman, XPS, and the AC impedance method. The discharge capacities of 1wt.%-LLTO-coated SP-Li1.2Ni0.2Mn0.60O2 composites were 256, 250, 231, 200, 158, and 114mAhg−1 at rates of 0.1, 0.2, 0.5, 1, 3, and 5C, respectively, in the voltage range 2.0–4.8V. The 1wt.%-LLTO-coated Li-rich oxide composite showed the discharge capacities of up to 256mAhg−1 in the first cycle at 0.1C. After 30 cycles, the discharge capacity of 244mAhg−1 was obtained, which showed the capacity retention of 95.4%.