In this paper, a new type lithium hexafluorophosphate (LiPF6) complex was prepared with a new method using phosphorus pentachlorine (PCl5), lithium fluoride (LiF) and 1,2-dimethoxyethane (C4H10O2). The structure of the complex was carefully characterized by FTIR, TG-DTG, 1H NMR and 31P NMR. FTIR results indicate that the synthesized complex is consisted of LiPF6 and C4H10O2. Chemical analysis shows that the content of LiPF6 in the complex is about 45%, which could infer that the mole ratio of LiPF6 and LiPF6(C4H10O2)2 in the complex is 1:2. The results of 1H NMR and 31P NMR further confirm the composition of the complex and determine the structure. The molecular formula of the LiPF6 complex is LiPF6(C4H10O2)2. Thermal analysis shows that the strong decomposition peaks of the complex appear at 75°C and 175°C. LiPF6(C4H10O2)2 may be used in the electrolyte of the lithium ion battery which 1,2-dimethoxyethane is permitted or broke down into LiPF6 after further preparation.