Watch a 46-minute symposium talk exploring recent advances in dynamical mean field-based electronic structure methods and their application to understanding correlated materials. Delve into the study of layered transition metal sulphides used in battery applications, examining how Hund's exchange coupling significantly influences their electrochemical properties. Learn about the battery charging process as a transformation from a high-spin Mott insulator to a low-spin correlated metal. Gain insights into how understanding these microscopic mechanisms could lead to improved battery materials development. The presentation, delivered at the Simons Foundation DMFT-QE Symposium, offers valuable perspectives on the intersection of theoretical physics and practical battery technology applications.