Triclinic LiTiOPO
4 fine powders were synthesized via low-temperature thermal treatment. First, amorphous fine powders were prepared by mechanical milling (MM) treatment of a mixture of the starting materials (Li
2CO
3, TiO
2, and P
2O
5) at room temperature. The mechanically milled amorphous powder formed a triclinic LiTiOPO
4 crystal below 700°C in air. The mechanically milled powders before heat treatment barely worked as an active material at ca. 0.1 C rate in the potential range of 1.0 to 3.0 V versus Li/Li
+ in lithium cells. On the other hand, the triclinic LiTiOPO
4 compounds obtained by the crystallization of the mechanically milled amorphous powders at 700°C in air worked as anode materials in lithium cells. The triclinic LiTiOPO
4 electrode materials exhibited capacities of around 100 mAh g
−1. The average operation potential was around 1.7 V (vs. Li/Li
+). The triclinic LiTiOPO
4 pristine compound when used as an anode caused a phase transition into an orthorhombic compound during lithium insertion (charge process). The orthorhombic compound changed into a triclinic phase during lithium extraction (discharge process). The triclinic LiTiOPO
4 electrodes exhibited a good cycle performance in the potential range of 1.0 to 3.0 V versus Li/Li
+. It is suggested that the crystalline phase changes reversibly during charge/discharge.
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