Preparation of fine single crystals of spinel-type lithium manganese oxide by LiCl flux method for rechargeable lithium batteries. Part 1. LiMn 2O 4

Abstract

Uniform fine single crystals of LiMn 2O 4 spinel were synthesized by a LiCl-Mn(NO 3) 2 flux method. The effects of reaction temperature and time on the composition, size and morphology of lithium manganese oxide were investigated by chemical, x-ray diffraction and selected area electron diffraction analyses, and SEM observation. The composition and size of the single crystals depended strongly on the heating temperature. Stoichiometric LiMn 2O 4 single crystals were yielded at 850°C, whereas lithium-rich and lithium-poor crystals were obtained at 650-750°C and 950°C, respectively. Plate-like Li 1.18Mn 2O 4.28 single crystals with a thickness of less than 0.1 μm, showed a high first discharge capacity of 112 mAh g -1 with a good cycle feature. The increase in the size of single crystals resulted in a decrease of the capacity at the first cycle, but did not accelerate the capacity fade over the following cycles.