Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Ying Li Project Name: Li-S_Trans Division: LCF Project title: Ion Transport in Lithium-Sulfur Solid Associated funding: DOE-ASCR Other Systems: Mira-BG/Q Science: Over the last few years, the novel Li-S battery has attracted a lot of attention due to its promising potential (e.g. high capacity, low cost, good cycleability, etc.) in beyond lithium ion battery development. In contrast to Li-insertion or Li-intercalated cathode materials, the thermodynamically huge energy is released when sulfur is undergoing a series of compositional, structural and morphological changes during discharge/charge cycling, when interacted with incoming or out-flowing of lithium ions on the cathode. To date, the details of ion transport and dynamics involved in the LixS solid or LixS films that formed at the Li-S battery cathode remains elusive. As a result, a detailed understanding of the ions dynamics and transport properties of Li-S solid are necessary to account for future commercialization of this new technology. While atomistic modeling based on electronic structures methods can help to explore the basic chemistry and electronic properties of LixS solid and its interfaces at the cathode, the methods have been limited to system size that cannot account for realistic dimensionality and morphologies of these LixS solid that present on the cathode. To complement to standard electronic structure studies of these LixS solids, one has to utilize the strength of classical Molecular Dynamics to look into the ion transport and dynamic properties of LixS solids with various morphologies. Project description: In this renewal proposal, we shall only focus on two fundamental problems, i.e. how the local structures and electronic properties of LixSy affect the following properties: (i) Li ions transport properties of LixS film with varied lithium concentration, x up to Li2S for a range of film thickness up to 50 nm (ii) effects of morphologies of Li ions transport (e.g. spherical particles vs. film configuration) with a range of lithium concentration, x up to Li2S. Based on our previous efforts in FY2016, we have employed Li-S force field developed by Islan, and van Duin et. al. Phys. Chem. Chem. Phys. 2015, 17, 3383 based on the LAMMPS software that available at LCRC to perform MD simulation on LixS with various morphologies. According to the most updated pre-compiled version of lammps-7Dec2015, we have benchmarked up to 8,000,000 atoms LiS crystal system with 50 x 50 x 50 nm3 with room temperature (300 K) under NVT ensemble. The time to solution for this system can be reached the minimum of 3.459174 seconds/step with 512 processors using 1 OpenMP thread per MPI task on Fusion. The strong scaling shows good scalability of LAMMPS with the current configuration. And recently, we have improved the ReaxFF force terms in the terms of OpenMP, with 4 OpenMP thread per MPI task on Blues, we have gotten 50% more efficiency of the code. In order to fulfill the goals of our focus study, we will (i) construct LixS film with x = 0.2, 0.6, 1.0, 1.4, 1.8 and 2.0 with film thickness d = 1, 2, 4 and 8 nm, respectively. In total, that’s 24 LixS systems cover the representive LixS solid film (ii) construct spherical LixS particles with x = 0.2, 0.6, 1.0, 1.4, 1.8 and 2.0 with radius r = 0.5, 1.0, 2 and 4 nm, respectively. In total, that’s 24 LixS systems cover the representive LixS particles. All of the configurations we constructed are expected to run within nanoseconds regime to reach thermal stability in simulation. In summary, we will use 200,000 CPU hours to achieve based on these plans. In the second half of FY2017, we will continue our project to study the local structures of the non-stoichiometric LixS systems by investigating the electrostatic charge distribution and electronic properties using Density Functional Theory (DFT) from the thermal equilibrated structures we obtained from the MD simulation during FY2016. The DFT calculation will presumably done using VASP, Quantum Espresso code for several bulk solid structures and bulk interfaces (i.e. ~ 300 – 500 atoms in simulation cell) with different stoichiometries of LixS within Gamma point in K-point grid. To study the molecular fragments that represents the various stoichiometries LixSy species, we will utilize Gaussian 09 code to investigate the underlying thermochemistry, vibration properties and possibly chemical reaction pathways. We anticipate that the request allocation for this renewal proposal would need 400,000 CPU hours to complete the study. Subsequently, these theoretical prediction and findings will be shared and validated by PI’s experimental colleagues at ANL, MIT, UIUC, Pacific-Northwest National Lab and Sandia National Lab within the DOE BES-JCESR consortium through the collaboration. In summary, we will need 200,000 CPU hours to complete our study in the coming FY2017 Industry partnership: N/A Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 400000 Q1: 100000 Q2: 100000 Q3: 100000 Q4: 100000 Justification: Storage requirements: Thank You, The LCRC Accounts System