Computational Materials Discovery: Disordered Cathode Materials for Li-Ion Batteries
Department of Materials Science and Engineering
University of California, Berkeley
12 PM, Monday, February 6th, 2017
1065 Kemper Hall
Abstract: Cation-disordered oxides have recently emerged as a promising new class of high-energy-density cathode materials for Li-ion batteries. Compared to conventional ordered oxides, such as layered LiCoO2 or spinel LiMn2O4, disordered rocksalt-type oxides offer improved structural stability, extraordinary reversible Li storage capacities, and a rich chemistry that holds the promise of yet undiscovered superior cathode materials.
Here, I will recap the fundamental roles that theory and computations have played in the discovery and understanding of this new materials class. First-principles calculations helped unravel the structural limitations of Li transport in ordered and disordered cathodes, and percolation theory predicted, in agreement with experiment, that Li excess is required to enable macroscopic Li transport in disordered oxides. Lattice model simulations have provided insight into the effect of cation disorder on the average voltage and the voltage profile, and the computational high-throughput screening of a large composition space identified novel cation-disordered compounds which were subsequently validated experimentally. The lessons learned from our work on disordered cathodes will be discussed in the general context of computational materials discovery. Finally, recent progress towards large-scale atomistic simulations beyond lattice models is presented.
Biography: Alexander Urban currently is a postdoctoral scholar in the Department of Materials Science and Engineering at UC Berkeley. Alex obtained his PhD in chemistry from FAU Erlangen-Nuremberg, Germany, for his work on coarse-grained electronic structure theory. During a postdoctoral stay in the Department of Materials Science and Engineering at MIT, he became acquainted with electrochemical energy storage technologies and investigated Li-ion battery materials using computational methods. His present research at UC Berkeley focuses on redox processes in Li-ion battery materials and on the general understanding of configurationally disordered materials.