Iron-based conversion cathode, FeOF is attractive, because of the low cost and the large specific capacity. However, the synthesis is not easy and it cannot be used as cathode against carbonaceous anode. To overcome these drawbacks, we focused on the LiFeOF phase, which has the same chemical composition as the discharged intermediate product of FeOF cathode. LiFeOF can be easily synthesized from LiF and FeO by the dry ball-milling method at room temperature. The reversible capacity was 292 mAh g<sup>−1</sup> with an average voltage of 2.5 V and an energy density over 700 Wh kg<sup>−1</sup>, which is higher than that of LiFePO<sub>4</sub>. In addition, we confirmed the feasibility of LiFeOF cathode against Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> anode.