Computational Design of New Magnesium Electrolytes with Improved Properties

Journal Article · 12 July 2017 · Journal of Physical Chemistry. C

DOI: https://doi.org/10.1021/acs.jpcc.7b04516 · OSTI ID:1480496

Qu, Xiaohui  ^[1]; Zhang, Yong  ^[2]; Rajput, Nav Nidhi  ^[1]; Jain, Anubhav ^[1]; Maginn, Edward  ^[2]; Persson, Kristin A. ^[3]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Univ. of Notre Dame, IN (United States)
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)

Here, we use computational design to examine 15 new electrolyte salt anions by performing chemical variations and mutations on the bis(trifluoromethane)sulfonamide (TFSI) anion. On the basis of our calculations, we propose two new anions as potential candidates for magnesium energy-storage systems, which are evolved from TFSI with the substitution of sulfur atoms in TFSI and the modification of functional groups. The applicability of these new anion salts is examined through comprehensive calculations using both first-principles as well as benchmarked classical molecular dynamics. We elucidate the important properties of these anions, including the electrochemical stability window, chemical decomposition, preferred solvation structure, diffusion coefficient, and other dynamical properties for 15 rationally designed molecules. Two of the designed anions are discovered to successfully avoid the vulnerability of TFSI during ion-pair charge-transfer reactions while retaining comparable or better performance of other properties. As such, our work provides, to our knowledge, the first theoretically designed electrolyte salt for contemporary multivalent batteries and provides guidance for the synthesis and testing of novel liquid electrochemical systems.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-06CH11357; AC02-05CH11231
• OSTI ID: 1480496
• Journal Information: Journal of Physical Chemistry. C, Vol. 121, Issue 30; ISSN 1932-7447
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English