Nano Co3O4 as Anode Material for Li-Ion and Na-Ion Batteries: An Insight into Surface Morphology

Co3O4 is regarded as a competent anode material for lithium and sodium ion batteries having high theoretical capacity of 890 mAh g(-1) obtained through metal displacement reaction with Li or Na. Nano Co3O4, consisting of 20-30 nm-sized particles was synthesized through a simple precipitation method and characterized through X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Transmission electron microscopy and X-ray photoelectron spectroscopy. Electrochemical evaluation of the nano Co(3)O(4 )as anode material for Li-ion and Na-ion batteries was performed through cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge cycling studies. Nano Co3O4 delivered high discharge capacity of 423 mAh g(-1) at 0.1 C even after 40 cycles as Li-ion battery anode and exhibited stable discharge behaviour up to 130 cycles with high rate capability. Nano Co3O4, in Na-ion configuration delivered discharge capacity of 101 mAh g(-1) at 0.1 C rate even after 30 cycles. At higher current rates Co3O4 electrodes exhibited severe capacity fading due to the huge volume change occurred during sodiation / desodiation. Ex-situ SEM and elemental analyses evidenced that disintegration of electrode structure resulting from volume change and continuous decomposition of electrolyte were responsible for the poor electrochemical performance of Co3O4 with Na+ ions while in Li-ion configuration nano Co(3)O(4 )outshined in cycling performance.