Abstract
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Orthorhombic LiMnO 2 was synthesized via a solid-state reaction. Its electrochemical properties as cathode in lithium batteries were examined. It was found that initially, a few cycles are necessary to activate the electrochemical reactivity of o-LiMnO 2, which is related to the transformation from the orthorhombic phase to a spinel-like phase. A maximum discharge capacity of 180-190 mA h g -1 for o-LiMnO 2 electrodes was achieved. An electrochemical impedance spectroscopy (EIS) study showed that the charge-transfer resistance (R CT) for the initial o-LiMnO 2 electrode is much larger than that for the o-LiMnO 2 electrode in the charged state. The o-LiMnO 2 electrode demonstrated a better cyclability than that of the spinel LiMn 2O 4 directly synthesized by solid-state reaction.