Synthesis and Characterization of Sn-Doped LiMn[sub 2]O[sub 4] Cathode Materials for Rechargeable Li-Ion Batteries

Abstract

Spinel LiSnxMn2−xO4LiSnxMn2−xO4 ( x=0x=0 , 0.02, 0.04) was synthesized based on the controlled crystallization. The process started with the preparation of pristine or Sn-doped MnCO3MnCO3 , followed by heat-treatment to produce the precursor Mn2O3Mn2O3 . Then, LiMn2O4LiMn2O4 was obtained by sintering of the mixture of Mn2O3Mn2O3 and Li2CO3Li2CO3 . The structural and electrochemical properties of as-prepared cathodes were investigated by X-ray diffraction, scanning electron microscopy, inductively coupled plasma-atomic emission spectrum, cyclic voltammetry, and charge–discharge cycling. The coin cells with LiSnxMn2−xO4LiSnxMn2−xO4 as the cathode were tested at a current density of 0.5mAcm−20.5mAcm−2 in the voltage range of 3.35–4.35V3.35–4.35V at room temperature and in the voltage range of 3.35–4.20V3.35–4.20V at 55°C55°C , respectively. The results show that the lattice constants of Sn-doped samples are reduced, but their cyclabilities are improved.