Electrochemical and Thermal Evolution of P2 Na2/3MnO2

The exploration of alternatives for lithium-ion batteries is an ongoing process due to the limited availability and high cost of lithium. Sodium-ion batteries (NIBs) have emerged as a promising candidate, as they have the potential to be cost-effective due to the high abundance of sodium in the Earth's crust. The cathode material, hexagonal (P2) Na 2/3 MnO 2 is an excellent cathode candidate in terms of cost and sustainability, but its electrochemical performance is impacted by structural phase transitions during cycling. In this study, the electrochemical-temperature-dependent phase diagram of P2 Na 2/3 MnO 2 is investigated using synchrotron X-ray powder diffraction. The structure at various states of charge is determined and their thermal evolution is evaluated. Despite the different states of charge, all materials were found to convert to cubic MnO at about 550°C. This talk will showcase the link between electrochemistry and crystallography.