Nanosized α-LiFeO₂ samples were successfully synthesized via a simple, quick and eco-friendly strategy at ambient temperature followed by a low temperature calcined process. X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electron microscopy (TEM) measurements revealed that the optimal α-LiFeO₂ sample was composed of extremely small nanoparticles. The electrochemical properties were tested at 0.1 C in the cut-off voltage of 1.5⁻4.8 V. The sample obtained at 150 °C for 6 h exhibited the best cycling stability with high initial discharge capacity of 223.2 mAh/g, which was extremely high for pristine α-LiFeO₂ without any modification process. After 50 cycles, the discharge capacity could still maintain 194.5 mAh/g with good capacity retention. When the charge⁻discharge rate increased to 0.2 C and 0.5 C, the initial discharge capacities were 216.6 mAh/g and 171.5 mAh/g, respectively. Furthermore, the optimal sample showed low charge transfer resistance and high lithium-ion diffusion coefficients, which facilitated the excellent electrochemical performance.
Keywords: ambient temperature; cathode material; nanoparticle; α-LiFeO2.