Electrochemical properties of BiFeO3 nanoparticles: Anode material for sodium-ion battery application

We report on synthesis and possibilities of utilizing BiFeO3 (BFO) nanoparticles and bulk materials as an anode component for sodium (Na) ion batteries. XRD and Raman spectroscopy measurements shows that as synthesized BFO exhibits rhombohedrally distorted perovskite structure. Cyclic voltammetry (CV) reveals that conversion redox mechanism takes place at first discharge and subsequently two alloying process. The specific capacity of BFO bulk material is seen to be 650 mAh/g at first cycle and gradually decreases to 250 mAh/g after 30 cycles (0.1 C rate). After 30 cycles, capacity fading takes place very slowly and is observed to be 180 mAh/g at 100th cycle. The discharge capacity of BFO material at different current rates is carried out and the better performance is seen at the current rates of 25 mA/g. The conversion reaction mechanism during the electrochemical reaction in BiFeO3 is probed by combining ex-situ XRD and XPS measurements after electrochemical cycling. CV of BFO nanoparticles exhibit very stable performance. Whereas, the charge discharge curve shows similar capacity fading as the bulk BFO. High initial capacity of BiFeO3 gives an indication that it can be utilized as an anode component for Na ion batteries after stabilizing the capacity fading.