The Energetic Landscape and Influence of Polarization for Site Swapping in Battery Cathode Materials

Improving energy storage technology to have rechargeable, high capacity, high energy density batteries is essential to transitioning towards renewable energy and vehicle electrification. One of the primary issues in lithium ion batteries is irreversible changes to the lattice structure of the cathode during charging and discharging cycles. These larger structural changes are often precipitated by site swapping between lithium and transition metal ions. While these structural changes are widely observed, the energetic landscape and mechanisms controlling the initial deviations from pristine structure are not yet understood. We have used computational methods including DFT and Madelung energy analysis to look at the atomic scale energetics and polarization effects of defects in a series of lithium iron oxide cathode materials to determine the mechanisms controlling structural stability within cathode materials.