Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Roy Benedek Project Name: LiBattModeling Division: CSE Project title: Lithium-Ion Battery Electrode Modeling Associated funding: Battery Materials Research Program, Office of Vehicle Technologies, U. S. Department of Energy Other Systems: NERSC (about 400K core hrs.) Science: We apply first-principles (density functional theory) techniques to investigate candidate lithium-ion-battery cathode materials. Our recent efforts address primarily lithium-rich transition metal (particularly Ni, Mn, and Co) oxides with layered structures. The objective is to identify high energy-density and low (voltage and capacity) fade compositions and structures. This modeling effort complements the experimental program led by Michael Thackeray and Jason Croy in the Battery Department of the CSE Division, ANL. Project description: We are performing simulations to elucidate the behavior of cathode materials that are candidates for use in next generation batteries for electrical vehicles. We are interested particularly in identifying structures that would help control voltage fade, a degradation process that prevents commercial use of an otherwise attractive class of materials, the lithium-rich layered oxides. Our previous simulations on the Li-rich layered oxides have addressed bulk behavior exclusively. Transformations of the atomic structure near the cathode surface (or interface with the electrolyte) during the first charge, however, appear critical to the processes that lead to voltage fade upon cycling. It is therefore reasonable to suppose that voltage fade cannot be effectively controlled without suppressing the surface (or interface) instabilities during the first charge, particularly the loss of oxygen. In the proposed work for FY17, we intend to explore the effectiveness of some approaches to suppress first-charge instabilities, such as surface doping or coating to stabilize the surface. We envision a treatment that limits the computational cell size to at most a few hundred atoms. We plan to simulate a slab oriented parallel to the crystallographic layers of xLi2(1-f)MnO3•(1-x)LiyMO2. The slab will be constructed with 2n+1 layers in such a way that the top and bottom surfaces are essentially identical. A slab with n=8, for example, would comprise 9 bulk-like layers (center of slab) and 8 near-surface layers. Initially, static calculations will be performed (with x=1), to estimate the energy of surface segregation of candidate dopants, such as Ru, V, and Ti for Mn in Li2MnO3. This will establish whether suitable polyvalent dopants are available that would tend to suppress oxygen loss at the cathode surface. Slabs will then be constructed that include near-surface dopant substitution for Mn. The stability of the doped slab relative to an undoped one will be explored with static and dynamical (first-principles molecular dynamics). The objective of this work to identify dopants that tend to stabilize the structure during the first charge, and therefore appear promising for experimental investigation. Besides doping, another approach to stabilization during the first charge is to apply a coating to the cathode surface. An attractive coating material is the spinel LiMn3/2Ni1/2O4, which is stable at high voltage. We will construct a slab in which the outer layers form an LiMn3/2Ni1/2O4 coating on Li2MnO3. Static and dynamical simulations will be performed to ascertain the stability during first charge of this model of a coated particle. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 800000 Q1: 200000 Q2: 200000 Q3: 200000 Q4: 200000 Justification: We have previously performed dynamical simulations with VASP for bulk materials. In FY17, we intend to extend those simulations to a slab geometry, to investigate surface properties. More CPU time will be required, but the simulation algorithms in VASP are expected to be no less efficient for the slab than for the bulk. Storage requirements: Thank You, The LCRC Accounts System