Tunneling and polaron charge transport through Li2O2 in Li-O2 batteries

A. C. Luntz*, V. Viswanathan, J. Voss, J. B. Varley, J. K. Nørskov, R. Scheffler, A. Speidel

*Corresponding author for this work

Research output: Contribution to journalLetterpeer-review

Abstract

We describe Li-O2 discharge experiments in a bulk electrolysis cell as a function of current density and temperature. In combination with a simple model, these imply that charge transport through Li2O 2 in Li-O2 batteries at practical current densities is based principally on hole tunneling, with hole polaron conductivity playing a significant role near the end of very low current discharges and at temperatures greater than 30 C. We also show that charge-transport limitations are much less significant during charging than those in discharge. A key element of the model that qualitatively explains all results is the alignment of the Li 2O2 valence band maximum close to the electrochemical Fermi energy and how this alignment varies with overpotentials during discharge and charge. In fact, comparison of the model with the experiments allows determination of the alignment of the bands relative to the electrochemical Fermi level.

Original languageEnglish
JournalJournal of Physical Chemistry Letters
Volume4
Issue number20
Pages (from-to)3494-3499
Number of pages6
ISSN1948-7185
DOIs
Publication statusPublished - 2013
Externally publishedYes

Fingerprint Dive into the research topics of 'Tunneling and polaron charge transport through Li<sub>2</sub>O<sub>2</sub> in Li-O<sub>2</sub> batteries'. Together they form a unique fingerprint.

Cite this