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

Abstract

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.