Microstructure and electrochemical performance of LiFePO4 cathode materials modified with binuclear metal aminophthalocyanines

Abstract

The monodispersed LiFe[Formula: see text]M[Formula: see text]PO4/C [[Formula: see text] [Formula: see text] 0.0040; [Formula: see text] = Mn[Formula: see text], Co[Formula: see text], Ni[Formula: see text], Cu[Formula: see text], Zn[Formula: see text]] nanocomposites obtained by LiFePO4 modified with binuclear metal aminophthalocyanines (M2(PcTa)2O and M2(PcTa)2C(CF[Formula: see text] are utilized as positive electrode materials for lithium ion batteries. The preparation method for these nanocomposites is a controllable solvothermal method using a mixture of ethylene glycol and [Formula: see text],[Formula: see text]-dimethylformamide as the solvent. The microstructure and electrochemical properties of the different nanocomposites are discussed and compared. The results show that the LiFePO4 samples modified with M2(PcTa)2C(CF[Formula: see text]can improve the initial discharge specific capacity of the lithium ion battery up to 154.2 mAh.g[Formula: see text]at the rate of 0.1 C, and 93.5% of the initial discharge capacity could be retained after 50 cycles. This research shows that the proposed process can enhance the electrochemical performance of high power LiFePO4 for lithium ion batteries.