Microwave-Assisted Mechanochemical Synthesis of Na0.67CoO2 as Potential Cathode Material Application in Sodium-Ion Batteries

Herein, we report synthesis of layer-structured P2-Na0.67CoO2 using facile mechanochemical approach assisted by microwave heating. This modification to the conventional synthesis route has enabled in obtaining a pure phase material at a significantly lower temperature and time than currently existing methods. Structural characterization reveals P2-type structure which is an electrochemically favorable structure for cathode material application. X-ray diffraction (XRD) data confirms the phase purity along with crystallite size (D) of 67.6 nm. SEM images reveal polyhedral structure with stacking of flake like morphology. Energy-dispersive spectroscopy (EDS) data indicates that the synthesized material matches with the expected stoichiometry with homogenously distributed elemental composition as seen from EDS mapping. Average particle size was measured to be 5.65 µm from the dynamic light scattering (DLS) measurements. Specific surface area was found to be 0.7 m2/g by Brunauer–Emmett–Teller (BET) method using N2 adsorption–desorption isotherm, with average pore size being 75.82 nm.