Microemulsion-Assisted Synthesis of Nanosized Li-Mn-O Spinel Cathodes for High-Rate Lithium-Ion Batteries

摘要

Li1.16Mn1.84O4 nanoparticles (50-90nm) with cubic spinel structure are synthesized by combining a microemulsion process to produce ultrafine Mn(OH)(2) nanocrystals (3-8nm) with a solid-state lithiation step. The nanostructured lithium-rich Li1.16Mn1.84O4 shows stable cycling performance and superior rate capabilities as compared with the corresponding bulk material, for example, the nano-sized Li1.16Mn1.84O4 electrode shows stable reversible capacities of 74mAhg(-1) during the 1000thcycle at a high rate of 40C between 3.0 and 4.5V. In addition, Li1.16Mn1.84O4 nanoparticles also show high Li storage properties over an enlarged voltage window of 2.0-4.5V with high capacities and stable cyclability, for example, delivering discharge capacities of 209 and 114mAhg(-1) at rates of 1 and 20C, respectively.