Synthesis and Characterization of LiMXFe1-XPO4 (M = Cu, Sn; X = 0.02) Cathodes - A study on the Effect of Cation Substitution in LiFePO4 Material

An attempt has been made for the possible augmentation and exploration of partially substituted LiFePO4 material as a positive electrode for lithium battery applications. In this regard, cationic substitution of Cu and Sn (2%) to the native LiFePO4/C electro active material has been carried out via. ball milling, with a view to understand the effect of respective transition and non-transition metals upon LiFePO4 individually. Uniformly distributed particles (SEM) of LiMXFe1-XPO4/C (M= Cu, Sn) with phase pure nature (XRD) and finer crystallite size (<1mm) were obtained. Further, it is interesting to note that irrespective of the nature of the dopant metal, the simple route of ball milled LiMXFe1-XPO4/C [M= Cu, Sn] cathodes endowed with improved conductivity and stable reversible capacity values (chare-discharge). In other words, the LiCu0.02Fe0.98PO4/C cathode delivered a reversible capacity of ~105 mAh/g with an excellent capacity retention characteristic. On the other hand LiSn0.02Fe0.98PO4/C cathodes exhibited an average specific capacity of ~100mAh/g with progressively enhanced efficiency values. Results of Fourier Transform Infra Red (FTIR) spectroscopy and Cyclic Voltammetric studies of LiMXFe1-XPO4/C (M= Cu, Sn) composites are also appended and correlated suitably.