Strongly Correlated Electrons in Rechargeable Battery Cathodes
Eric Isaacs, Columbia University
A sustainable energy future requires not only the ability to generate power from renewable sources, but also the means to efficiently and reliably store it until used. The rechargeable battery is an energy storage technology that relies critically on a transition metal oxide cathode material with the ability to reversibly intercalate Li ions. Due to the strong correlations associated with d electrons, the standard theory of materials science – density functional theory (DFT) – breaks down in describing battery cathode materials. Here we merge DFT with a sophisticated many-body approach called dynamical mean-field theory (DMFT) to describe the impact of strong electronic correlations on the properties of two quintessential cathode materials, LixCoO2 and LixFePO4. First, we employ an approximate mean-field solution to the DMFT equations to unravel the essential role of the electronic correlations on battery phase stability. Employing a new massively parallelized quantum Monte Carlo DMFT solver, we then compute the battery voltage and phase stability of these materials within DFT+DMFT for the first time. This methodology may significantly contribute to the accurate computational description and screening of battery materials in the future.
Abstract Author(s): E.B. Isaacs, C.A. Marianetti