Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Lei Cheng Project Name: ElectrolyteRedoxFlow Division: MSD Project title: discoveries of electrolyte for redox flow batteries Associated funding: JCESR Other Systems: NERSC Science: To meet global energy demand, renewable energy sources such as solar and wind energy are being developed and utilized. The increased use of wind and solar energy will challenge the grid’s ability to provide a stable electrical supply around the clock. Grid energy storage can be used to shift load from peak to off-peak hours and redox flow batteries are of particular interest to perform this load leveling. Redox flow batteries differ from classical batteries in that energy is stored in the liquid electrolyte in separate liquid reservoirs instead of in the electrode. This bypasses common electrode degradation issues observed in lithium ion batteries and makes the battery systems more durable and scalable. However, all flow batteries based on aqueous electrochemical couples are limited by the electrochemical properties of water which is only stable within a small potential window (typically 1.2-1.6 V) outside of which water electrolysis occurs. This means that redox- flow battery suffers from lower energy density. In order to increase the energy density, the current or potential must be increased. Employing non-aqueous electrolytes offers a wider window of electrochemical stability, enabling flow batteries to operate at higher cell potentials (>2 V) and eliminating this low energy density limitation. Among various fundamental science and engineering challenges in the design of more efficient redox flow batteries, discoveries of appropriate redox couples that operate at higher cell voltage will lead to greater system energy densities and higher energy efficiencies. It is also one of the important missions of the energy storage hub Joint Center for Energy Storage Research (JCESR). Project description: In this renewal work, we will continue focusing on fundamental properties of transition metal complexes as redox active molecules for non-aqueous redox flow battery application. In collaboration with experimental group (Prof. Thompson, University of Michigan), we have previously studied redox windows of some novel compounds. We now study the solubilities of these compounds in non-aqueous solutions as the capacity of this type of battery is directly proportional to redox window and concentration of active compound in solution. Insight gained from these studies will greatly guide design and synthesis of the compounds experimentally. In previously proposed work, we have successfully determined the B3LYP/6-31+G* and BP86/6-31+G* combinations as proper computational treatments for these system. The same methods will be used to calculate solvation energies of Cr, V, Mn and Fe based novel compounds. These energies will be calculated using both implicit continuum models such as PCM, CPCM and SMD methods, as well as explicit model with actual solvent molecules added to the quantum calculations. These solvation energies will then be compared with experimentally measured solubilities of the compounds to determine correlation between the two. Calculations with explicit solvent molecules will also be performed to further validate accuracy of the implicit model calculations as well as provide more insights on coordination details of the metal complexes by solvent molecules. Recently, interesting solubility trends of metal complexes in different binary organic solvents have been observed experimentally (private com munication). We will also guide our research efforts towards providing physical understandings of the observed experimental results. All calculations will be performed using Gaussian and NWCHEM. These two code packages are both considered very efficient and reliable for quantum chemistry calculations. Gaussian is not very scalable but it provides really robust geometry optimizer and the G3/G4 methods are built-in. NWChem is very scalable especially for higher level calculations such as coupled cluster methods and perturbation theories. After interesting molecule candidates and appropriate calculation methods are identified, derivatives of these molecules will be subject to high-throughput screening. The high-throughput screening will be performed using NERSC supercomputers. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 600000 Q1: 150000 Q2: 150000 Q3: 150000 Q4: 150000 Justification: The size of molecules we propose to study is very typical for the two computational software (Gaussian and NWChem) so they scale reasonably well for most DFT calculation. The higher level calculations will consume more memory as well as computational time. The NWChem code uses a globally-shared memory system, therefore one can request and utilize more memory through node parallelization. Storage requirements: Thank You, The LCRC Accounts System