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Title: Sigma-Holes in Battery Materials Using Iso-Electrostatic Potential Surfaces

The presence of highly electronegative atoms in Li-ion batteries anticipates the formation of σ-hole regions that may strongly affect the ionic conductivity. The σ-hole consists of a region of positive electrostatic potential extending in the direction of the covalent bond between atoms of groups IV–VII due to anisotropic charge distribution. Graphite electrodes in Li-ion batteries that become halogenated due to the electrolyte, as well as some solid electrolyte materials, can exhibit these σ-holes. Since Li-ions should be able to drift in any part of the battery, the fact that they can be attracted and eventually absorbed by regions of strong negative potentials produced by high-electronegativity counterions becomes detrimental to ionic conductivity. Therefore, the presence of positive well-defined regions, repulsive to the Li-ions, might act as lubricant for Li-ions drifting through electrolytes, thus improving the Li-ion conductivity. In addition, the σ-holes might also have a strong effect on the formation of the passivating layer, known as the solid electrolyte interphase (SEI) at electrode surfaces, which is of paramount importance for the performance of rechargeable batteries. Here we investigate the existence of σ-holes on surfaces of graphite anodes and of a few solid electrolytes by examining the electrostatic potentials calculated using densitymore » functional theory« less
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering
  2. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering
  3. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering, Dept. of Electrical and Computer Engineering
  4. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering and Dept. of Materials Science and Engineering, and Dept. of Chemistry
  5. Texas A & M Univ., College Station, TX (United States). Dept. of Chemical Engineering, Dept. of Electrical and Computer Engineering, and Dept. of Materials Science and Engineering
Publication Date:
Grant/Contract Number:
EE0008210
Type:
Accepted Manuscript
Journal Name:
Crystals
Additional Journal Information:
Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2073-4352
Publisher:
MDPI
Research Org:
Texas A & M Univ., College Station, TX (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
Contributing Orgs:
Texas A&M High Performance Research Computing and Texas Advanced Computer Center (TACC)
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; density functional theory; ionic conductivity; solid electrolytes; solid-electrolyte interphase
OSTI Identifier:
1460761