Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 2: Battery Materials
MM 2.2: Vortrag
Montag, 12. März 2018, 10:30–10:45, H 0106
Effect of stress/strain on ionic and electronic conductivity in LiCoO2 cathode material — •Ashkan Moradabadi and Payam Kaghazchi — Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195, Berlin
It has been revealed that stress/strain can affect conductivity of materials up to several orders of magnitude [1]. In this study, we have investigated the influence of stress/strain on charge carrier mobilities in bulk LiCoO2 using an ab initio-based “elastic dipole tensor” concept. It is shown that only 1% lateral tensile strain can increase the ionic conductivity in bulk LiCoO2 more than two times [2]. The effect of longitudinal strain on ionic conductivity is even more significant [2]. Moreover, we calculated the electronic conductivity in bulk LiCoO2 using hole-polaron hopping model. Our estimated value for the electronic conductivity is 2.7×10−4 S/cm [3] which is in good agreement with experiments (1.0-3.3×10−4 S/cm [4]). We find that the effect of stress/strain on ionic conductivity is stronger than that of the electronic one. By comparing the results obtained by this method and those calculated by DFT-NEB, we show that the “elastic dipole tensor” method can be used to estimate conductivity of materials under any given strain field with low computational and time effort.
[1] J. Garcia-Barriocanal et al., Science, 2008, 321, 676-680. [2] A. Moradabadi et al., submitted to Phys. Rev. Mats., 2017, arXiv: 1706.01709. [3] A. Moradabadi et al., Phys. Rev. App., 2017, 7 (6), 064008. [4] Qiu et al., Phys. Chem. Chem. Phys., 2012, 14, 2617-2630.