Synthesis of One-dimensional Spinel LiMn 2 O 4 Nanostructures as a Positive Electrode in Lithium Ion Battery

This paper presents the synthesis of one-dimensional spinel LiMn 2 O 4 nanostructures using a facile and scalable two-step process. LiMn 2 O 4 nanorods with average diameter of 100 nm and length of 1.5 μm have been prepared by solid-state lithiation of hydro-thermally synthesized β-MnO 2 nanorods. LiMn 2 O 4 nanowires with diameter of 10 nm and length of several micrometers have been fabricated via solid-state lithiation of β-MnO 2 nanowires. The precursors have been lithiated with LiOH and reaction temperature and pressure have been controlled. The complete structural transformation to cubic phase and the maintenance of 1-D nanostructure morphology have been evaluated by XRD, SEM, and TEM analysis. The size distribution of the spinel LiMn 2 O 4 nanorods/wires has been similar to the MnO 2 precursors. By control of reaction pressure, cubic 1-D spinel LiMn 2 O 4 nanostructures have been fabricated from tetragonal MnO 2 precursors even below 500℃.