Partially fluorinated lithium manganese spinel oxides (LiMn1.8Li0.1Ni0.1O4−x F x ) were prepared by solid-state reaction. Relationship between the electronic structures of LiMn1.8Li0.1Ni0.1O4−x F x and their electrochemical properties were investigated. X-ray absorption near-edge structure (XANES) of Mn K-edge showed that the absorption edge shifted to lower energy with increasing F− content, which indicated decrease of the Mn average oxidation state. Discharge capacity at first cycle was increased by decrease of the Mn average oxidation state with increasing F− content.