Scalable synthesis and surface stabilization of Li2MnO3 NWs as high rate cathode materials for Li-ion batteries

摘要

Li2MnO3 nanowires (NWs) are synthesized using a scalable two-step process involving a solvo-plasma technique, utilizing inexpensive precursors such as commercially available MnO2 microparticle powders and KCl, followed by a solid state lithiation process. Lithium manganese oxide (Li2MnO3) nanowires exhibited high capacity retention of 120 mA h g(-1) in the 2-4.5 V voltage window even at high C-rates such as 20 C. The specific capacity of the Li2MnO3 NWs gradually increased with cycling and subsequently stabilized. Further, the Li2MnO3 NW cathodes exhibited no loss in the capacity for 100 cycles with close to 100% coulombic efficiency. Most importantly, single crystalline Li2MnO3 nanowires with short transport length scales for Li, O and Mn atoms along the radial direction allow for the formation of a thick and conformal LiMn2O4 shell resulting in increased capacity, excellent capacity retention and high coulombic efficiencies.