Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Rajeev Surendran Assary Applicant's institution: ANL Applicant's division: MSD Project Name: QM_Storage Project title: Organic Materials for Energy Storage Associated funding: BES: JCESR Other Systems: CNM Science: Understanding, controlling, and eventually manipulating functional groups on promising organic molecules can be used to obtain the wide electrochemical window needed for the next generation of non-aqueous redox flow battery electrolytes. Combined electrochemical measurements in combination with accurate quantum calculations to probe structure-activity relationships of redox active molecular (RAM) species and to study their interactions with the surrounding electrolyte with an overall goal of developing key descriptors for predicting performance and stability of various organic compounds is central to this project. Predictive quantum chemical simulations based on density functional theory is utilized to compliment electrochemical experiments to investigate the redox properties of redox active organic molecules. The project is an integral part of the Materials Discovery associated with the Non-aqueous redox flow thrust of Joint Center of Electrical Ene rgy Storage (JCESR) at the Argonne National Laboratory. Project description: Project Description Electronic-structure based calculations have been extensively used to investigate the electronic structure of redox couples, while their application for explaining the electrochemical processes in redox flow batteries has been largely unexplored. Using the density functional theory framework, we will address a priori understanding of important electrochemical studies such as the following, as shown in Scheme 1. 1) Redox windows 2) Substitutent effects on improving the redox windows 3) Detailed computations to explore the side reactions 4) Assess the stability of cations/anions 5) Reactivity of molecules/ions at the electrode interphase. For organic materials (selected materials shown in Scheme1) we intend to derive a computational database that includes redox windows, solvation and stability. Detailed computations are required to compute stability of ions/molecules in the solution during electrochemical charge and discharge. Numerous parameters control the stability of redox shuttles and their cyclability, such as thermodynamic and kinetic processes. In order to understand the thermodynamic stabilities, computation of thermochemistry of likely decomposition reactions offers valuable assistance. Firstly, both free energies and enthalpies of possible reactions in solution phase provide information on the likelihood of such decomposition reactions (fragmentation, auto oxidation, rearrangements) and the design of redox compound. Secondly calculations of reaction barriers enable us to predict whether a particular reaction would proceed under specific reaction conditions. Rate constants decomposition reactions can be computed using this approach. We intend to compute the properties using density functional methods and validate their accuracies against high-level ab-ini tio methods for select cases. The stability of cationic or anionic species in the redox flow batteries are often controlled by the solvent effect and the understanding of their lifetime and reactivity vs. time and temperature is another very important aspect that we will explore using ab initio dynamics simulations. Note that this is computationally time consuming and require lengthy simulations. State-of-the-art quantum chemical calculations are a powerful tool in the search for new redox candidates. Prediction of computed redox potentials and stability of redox couples will enable experimentalists to avoid performing unnecessary experiments and hence reduce the cost for discovery. Existing molecules can be modified by ligand substitution, which can adjust the redox potential. Our research group has shown proof of this principle for silicon-based electrolytes previously (Assary et.al, J Phys Chem C 2011, 115, 12216). We have already established limited computational guidelines for selected organic molecules (quinoxaline) and sulfur (S8) for obtaining structure-electrochemical activity relationships, especially for the estimation of electrochemical windows. . From these studies, compounds with desired potential range, effect of electron withdrawing and electron donating groups, effect of salts, solvents on redox potential can be obtained. These studies will be further expanded to to include computational results for stabilities using chemical reactivity indexes and transition state theory. These results will be provided to JCESR collegues via PowerPoint presentation and to scientific communities via peer reviewed publications. Following list suggest some early breakthroughs from my research related to the energy storage of organic materials from computational studies: 1. Towards a molecular level understanding energetics in Li-S batteries using a non-aqueous electrolyte: A high-level quantum chemical study. Rajeev S. Assary†, Larry A Curtiss, Jeff Moore, Journal of Physical Chemistry C, 2014, 118, 11545-58. 2. Investigation of the Redox Chemistry of Anthraquinone derivatives using density functional study, Jonathan Bachman, Larry A. Curtiss, Rajeev S. Assary†, Journal of Physical Chemistry A, 2014, DOI: 10.1021/jp5060777. 3. Liquid Redox Active Molecules towards Non-aqueous Flow Battery, Jinhua Huang, Lei Cheng, Rajeev S. Assary, Anthony K. Burrell, Larry A. Curtiss, Lu Zhang, 2014, submitted. 4. Reduction potential Prediction of Some Aromatic Nitrogen Containing Molecules, Rajeev S. Assary†, Fikile R. Brushett, and Larry A. Curtiss, 2014, submitted. 5. BF3-Promoted Redox Activity if Quinoxaline in Aprotic Solvents, Emily Carino, Charles E. Diesendruck, Larry A. Curtiss, Rajeev S. Assary†, Fikile R. Brushett, 2014, submitted. Industry partnership: NONE Project URL: Requested allocation: 500000 Q1: 100000 Q2: 100000 Q3: 150000 Q4: 150000 Justification: Quantum chemical calculations will be performed using Gaussian 09 and CPMD softwares, both of them are available in LCRC computer clusters. The PI has extensive experience in effectively using these software packages and obtaining meaningful results in a timely manner. Gaussian 09 is scalable upto 64 processors. Mainly required to perform long and vast number of jobs. CPMD is a well parallelized software available in LCRC machines. Storage requirements: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System