Potential Energy Surfaces and Charge Transfer of PAH-Sodium-PAH Complexes

Eirik Hjertenaes; Stefan Andersson; Henrik Koch

doi:10.1002/cphc.201600353

Potential Energy Surfaces and Charge Transfer of PAH-Sodium-PAH Complexes

Chemphyschem. 2016 Sep 19;17(18):2908-15. doi: 10.1002/cphc.201600353. Epub 2016 Jul 15.

Authors

Eirik Hjertenaes¹, Stefan Andersson², Henrik Koch^{3

4}

Affiliations

¹ NTNU Norwegian University of Science and Technology, Trondheim, Norway.
² SINTEF Materials and Chemistry, P.O. Box 4760, 7465 Trondheim, Norway.
³ NTNU Norwegian University of Science and Technology, Trondheim, Norway. henrik.koch@ntnu.no.
⁴ Department of Chemistry and the PULSE Institute, Stanford University, Stanford, CA, 94305, USA. henrik.koch@ntnu.no.

PMID: 27303941
DOI: 10.1002/cphc.201600353

Abstract

To further understanding of the role of sodium in carbon cathode degradation in Hall-Héroult cells, potential-energy surfaces and charge-transfer curves are presented for finite-size complexes of sodium intercalated between various polycyclic aromatic hydrocarbons. Calculations for lithium and potassium are included to highlight the disparate intercalation behaviour of the alkali metals in graphite intercalation compounds. Static energy barriers from DFT are used to compute macroscopic diffusion coefficients according to transition-state theory. Comparing the calculated diffusion coefficient to experimental values from the literature sheds light on the role of lattice diffusion of sodium-graphite intercalation compounds in sodium intrusion in graphitic carbon cathodes.

Keywords: density functional calculations; electrochemistry; graphite; intercalations; sodium.