Influence of synthesis parameters on the physicochemical and electrochemical properties of LiFePO4 for Li-ion battery

LiFePO4 (LFP) has been developed as a cathode for lithium ion batteries (LIBs) by solution combustion method. The present work includes effect of fuel, residual carbon and graphene oxide on the phase purity and electrochemical performance of combustion synthesized LiFePO4. As revealed in XRD, single phase LiFePO4 is obtained in glycine assisted combustion (G-LFP) and it delivers 97 mA h/g discharge capacity, which is higher than urea assisted combustion (U-LFP). Further, the G-LFP was calcined for different lengths of time (4, 5 and 7 h). The amount of in-situ carbon is observed to decrease from 2.57 to 1.40% and specific capacity increases from 97 (4 h) to 106 mA h/g (7 h). The composites with 4 wt % GO were formed and they show enhanced electrochemical performance. 5LFP/GO delivers discharge capacity of 164 mA h/g at 0.1 C, which is 96% of its theoretical capacity.