Preparation of LiMn2O4 by two methods for lithium ion batteries

Spinel LiMn2O4compounds were synthesized by two different methods: spray-drying a mixture of corresponding metal acetates, and traditional solid-state reaction. Phase composition, morphology and particle size of as-prepared materials were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Both materials showed well-defined single-phase spinel LiMn2O4. However, the morphology, particle size and distribution exhibited distinct difference. The electrochemical properties of the cathodes were measured in the coin-type cells in a potential range of 3.20-4.35 V versus Li/Li+. Both cyclic voltammogram curves exhibited two pairs of well-defined redox reaction peaks. Initial discharge capacity (at a rate of 1/10C) of the LiMn2O4 synthesized by spray-drying method and solid-state reaction was 123 and 117 mAh g−1, respectively. At a high rate of 2C, however, the discharge capacity was 107 and 83 mAh g−1, respectively. And also, cycle life properties of both materials were evaluated.