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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 5: Energy Materials: Water Splitting, Batteries, and Supercapacitors (original: HL, joined by CPP)
CPP 5.5: Talk
Monday, March 31, 2014, 11:45–12:00, POT 081
First principles study on the electronic properties of NaO2 — •Markus Heinemann1, Pascal Hartmann2, Conrad L. Bender2, Philipp Adelhelm2, Jürgen Janek2, and Christian Heiliger1 — 1I. Physikalisches Institut, Justus Liebig University, 35392 Giessen, Germany — 2Physikalisch-Chemisches Institut, Justus Liebig University, 35392 Giessen, Germany
In the light of the recent discovery of rechargeable room-temperature sodium superoxide (NaO2) batteries [1], a deeper understanding of the electronic properties of NaO2 has become of broad interest. We investigate the electronic structure of NaO2 using the framework of density functional theory and employ a hybrid functional approach for the exchange and correlation interaction. The disordered pyrite structure of the NaO2 room-temperature phase is modeled by taking into account various superoxide orientations in our computations. Our band structure calculations indicate that NaO2 is an insulator with an energy band gap in the range of 2 eV and that different superoxide alignments lead to a broadening of the conduction band. We compare our calculations to recent experimental investigations on the conductivity of NaO2.
[1] P. Hartmann, C. L. Bender, M. Vračar, A. K. Dürr, A. Garsuch, J. Janek, and P. Adelhelm, Nature Mat. 3486, 1 (2012)