Low hole polaron migration barrier in lithium peroxide
Name
Ong-2012-Low hole polaron migration barrier in lithium peroxide.pdf
Size
361.13 KB
Format
Adobe PDF
Checksum (MD5)
3fc605f4e0dcf94c63a4df8c83396c81
Author(s)
Ong, Shyue Ping
Mo, Yifei
Ceder, Gerbrand
Date Issued
February 2012
Journal
Physical Review B
Publisher
American Physical Society
Citation
Ong, Shyue, Yifei Mo, and Gerbrand Ceder. “Low Hole Polaron Migration Barrier in Lithium Peroxide.” Physical Review B 85.8 (2012). ©2012 American Physical Society
Version
Final published version
Abstract
We present computational evidence of polaronic hole trapping and migration in lithium peroxide (Li[subscript 2]O[subscript 2]), a material of interest in lithium-air batteries. We find that the hole forms in the π* antibonding molecular orbitals of the peroxide (O2[superscript 2−]) anion, and that this trapped hole induces significant local lattice distortion, forming a polaron. Our study finds migration barriers for the free polaron to be between 68 and 152 meV, depending on the hopping direction. This low barrier suggests that this material might not be as insulating as previously assumed, provided that the formation of carriers can be achieved. One transport limitation may arise from lithium vacancies, which we find to strongly bind to the polaron. This result, in combination with previous experimental results, suggests that electronic conductivity in this material is likely to be determined by vacancy diffusion.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevB.85.081105
