Synthesis and electrochemical properties of high performance yolk-structured LiMn2O4 microspheres for lithium ion batteries

Yolk-structured microspheres of spinel LiMn2O4 are successfully prepared by a specially designed multi-step synthesis procedure involving precipitation, controlled oxidation, selective etching and chemical lithiation. Solid-structured and hollow-structured LiMn2O4 are also synthesized by a similar method for comparison. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller method and IR spectroscopy are employed to study their structures and compositions. The electrochemical properties of the LiMn2O4/Li cells are also tested. The results indicate that LiMn2O4 powder composed of yolk-structured microspheres possesses remarkable high rate capability and outstanding high capacity retention not only at room temperature but also at elevated temperatures. This study may provide significant new insight into restraining the capacity fading of LiMn2O4 electrodes and the yolk-structured LiMn2O4 may be used for the next generation of lithium ion batteries.