Electrophoretically deposited bismuth iron oxide as dual role anode material for both lithium and sodium-ion batteries

Currently, the implementation of new energy storage technologies is very crucial to deal with ever growing energy demand. Identifying a suitable dual role anode materials that have the ability of storing both alkali metal ions of lithium as well as sodium and simultaneously inspecting their reaction mechanism are anticipated to be very significant for advance battery storage technologies. To enable superior electrochemical characteristics, we have fabricated the electrodes using electrophoretic deposition (EPD). The EPD grown BFO anode exhibits impressive rate performance (similar to 465 mAhg(-1) and 151 mAhg(-1) at current density of 0.1 Ag-1 and 6.4 Ag-1, respectively) and cyclability during lithium storage in consonance with previously reported values in the literatures. BFO anode yields stable discharge capacity of similar to 425 mAhg(-1), is retained after 60 cycles and most importantly barring first few cycles, there is no sign of capacity fading. The charge-discharge behavior of BFO anode has been interpreted through conversion reaction mechanism by using ex-situ X-ray diffraction, microstructural, differential capacity analysis and correlate with its electrochemical impedance spectroscopic study. Along with the lithium storage, the concept of dual role operation of this anode material has been demonstrated by investigating the sodium storage characteristics in detail. When BFO is used for SIB anode, it represents highly reversible, stable discharge capacity of similar to 223 mAhg(-1), maintained beyond 100 cycles and the Coulombic efficiency always remains 98%. We believe that uniform distribution of conducting carbon in BFO matrix provides a conductive electronic wiring along with the stronger adhesion between electrode and underlying current collector has played an influential role in achieving superior electrochemical performance for both Li and Na-ion rechargeable cell. In this work, EPD grown uniform BFO structure contributes a favourable path to uptake Li and Na ion by conversion reaction, therefore it could be utilized for the development of new dual role anode material.