The synthesis and characterization of nanosized orthorhombic LiMnO2 by in situ oxidation–ion exchange

Nanosized orthorhombic LiMnO2 (o-LiMnO2) with high purity and good crystallinity has been synthesized by a simple process under mild conditions (80 °C) involving controlled oxidation of Mn(OH)2 followed by in situ ion exchange of lithium ions with the resulting intermediate MnOOH (in situ oxidation–ion exchange). By studying the effects of varying the lithiating agent, the oxidant and washing conditions, a mechanism for the synthesis of nano o-LiMnO2 by this method has been proposed. Nano o-LiMnO2 obtained by in situ oxidation–ion exchange has a high capacity with an initial discharge capacity of 220 mAh g−1and a good cycling performance with a reversible capacity of 194 mAh g−1 after 30 cyclings, indicating that it is a potential synthetic method for the positive electrode material of lithium ion secondary batteries.