![]() Using spectroscopic tools, we quantify the fraction of ion pairs that forms within the electrolyte. We study different tetrabutylammonium (TBA) salts in two electrolyte systems with glyme ethers (e.g., 1,2 dimethoxyethane or DME) and dimethyl sulfoxide (DMSO) as a low and high dielectric constant medium, respectively. In this work, we show that the more » bulk solvation behavior within the nonaqueous electrolyte can control the CO2 reduction reaction and product distribution occurring at the catalyst-electrolyte interface. However, the influence of ion solvation and solvent selection within nonaqueous electrolytes for efficient and selective CO 2 reduction is unclear. Fortunately, aprotic solvents can circumvent HER, making it important to develop strategies that enable integrated CO 2 capture and conversion. However, most research efforts on electrochemical CO 2 conversion use aqueous media and are plagued by competing hydrogen evolution reaction (HER) from water breakdown. Industrially, CO 2 is captured using a variety of aprotic solvents due to their high CO 2 solubility. Selective CO 2 capture and electrochemical conversion are important tools in the fight against climate change. These results highlight the importance of the interplay between ion–solvent and ion–ion interactions for manipulating the energetics of intermediate species produced in aprotic metal–oxygen batteries. The solvation energy of Li + trended with donor number (DN), and varied greater than that of O 2 − ions, which correlated with acceptor number (AN), explaining a previously reported correlation between Li + ‐O 2 − solubility and DN. Increasing combined solvation of Li + and O 2 − was found to lower the coupling of Li + ‐O more » 2 − and the difference between O 2 /Li + ‐O 2 − and O 2 /O 2 − potentials. Standard potentials of O 2 /Li + ‐O 2 − and O 2 /O 2 − were experimentally measured and computed using a mixed cluster‐continuum model of ion solvation. (ANL), Argonne, IL (United States) Sponsoring Org.: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Joint Center for Energy Storage Research (JCESR) USDOE Office of Science (SC), National Energy Research Scientific Computing Center (NERSC) Argonne National Laboratory, Laboratory Computing Resource Center OSTI Identifier: 1393255 Grant/Contract Number: AC02-06CH11357 Resource Type: Journal Article: Accepted Manuscript Journal Name: Journal of the Electrochemical Society Additional Journal Information: Journal Volume: 164 Journal Issue: 11 Journal ID: ISSN 0013-4651 Publisher: The Electrochemical Society Country of Publication: United States Language: English Subject: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY 25 ENERGY STORAGE DFT solubility battery Li = ,Ībstract Understanding and controlling the kinetics of O 2 reduction in the presence of Li + ‐containing aprotic solvents, to either Li + ‐O 2 − by one‐electron reduction or Li 2 O 2 by two‐electron reduction, is instrumental to enhance the discharge voltage and capacity of aprotic Li‐O 2 batteries. Publication Date: Research Org.: Argonne National Lab. (ANL), Argonne, IL (United States) California State Univ., Northridge, CA (United States) In conclusion, the calculated LiO 2 and Li 2O 2 solubilities provide important information for fundamental studies of discharge and charge chemistries in Li-O 2 batteries. The difference in solubilities between LiO 2 and Li 2O 2 likely will affect the nucleation and growth mechanisms and resulting morphologies of the products formed during battery discharge, influencing the performance of the battery cell. The computed solubility of LiO 2 (1.8 × 10 -2 M) is about 15 orders higher than that of Li 2O 2 (2.0 × 10 -17 M) due to a much less negative lattice energy of bulk LiO 2 compared to that of Li 2O 2. Best estimates for the solvation energies from these calculations along with calculated lattice energies of Li 2O 2 and LiO 2 were used to determine the solubility of bulk LiO 2 and Li 2O 2. In this contribution, the solvation free energies of molecular LiO 2 and Li 2O 2 in various organic solvents were calculated using various explicit and implicit solvent models, as well as ab initio molecular dynamics (AIMD) methods. Knowledge of the solubilities of Li 2O 2 and LiO 2 in aprotic solvents is important for insight into the discharge and charge processes of Li-O 2 batteries, but these quantities are not well known.
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