ORALS
SESSION: AdvancedMaterialsMonPM1-R6
| 4th Intl. Symp. on New and Advanced Materials and Technologies for Energy, Environment and Sustainable Development |
| Mon Nov, 5 2018 / Room: Guaratiba (60/2nd) | |
| Session Chairs: Janina Molenda; Michael Zharnikov; Session Monitor: TBA |
14:50: [AdvancedMaterialsMonPM107] Invited
The Impact of Cathode Electronic Structure on the Parameters of Lithium and Sodium Batteries Janina
Molenda1 ;
1AGH University of Science and Technology, Kraków, Kraków, Poland;
Paper Id: 22
[Abstract] The author of this work, based on her own investigations of A<sub>x</sub>MO<sub>2</sub> cathode materials (A=Li, Na; M=3d), has demonstrated that the electronic structure of these materials plays an important role in the electrochemical intercalation process. The proposed electronic model of intercalation [1-3] is universal and has outstanding significance with regard to tailoring the properties of electrode materials to the most efficient application in Li-ion and Na-ion batteries.
The paper reveals correlation between electronic structure, transport, and electrochemical properties of layered Li<sub>x</sub>CoO<sub>2</sub>, Na<sub>x</sub>CoO<sub>2</sub> and Li<sub>x</sub>Ni<sub>1-y-z</sub>Co<sub>y</sub>Mn<sub>z</sub>O<sub>2</sub> cathode material and explains of apparently different character of the discharge/charge curve in Li<sub>x</sub>CoO<sub>2</sub> (monotonous curve) and Na<sub>x</sub>CoO<sub>2</sub> systems (step-like curve). Comprehensive experimental studies of physicochemical properties of Li<sub>x</sub>Ni<sub>1-y-z</sub>Co<sub>y</sub>Mn<sub>z</sub>O<sub>2</sub> cathode material (XRD, electrical conductivity, thermoelectric power) are supported by electronic structure calculations performed using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) to account for chemical disorder. It is found that even small O defects (~1%) may significantly modify DOS characteristics via formation of extra broad peaks inside the former gap leading to its substantial reduction. Furthermore, the variations of the electromotive force of the Li/Li<sup>+</sup>/Li<sub>x</sub>Ni<sub>1-y-z</sub>Co<sub>y</sub>Mn<sub>z</sub>O<sub>2</sub> cell (for 0 < x < 1) remains in quite good agreement with the relative variation of EF on DOS calculated from the KKR-CPA method.
References:
[1] J. Molenda, D. Baster, M. Molenda, K. Świerczek, J. Tobola, Phys. Chem. Phys. Chem. 16 (2014) 14845
[2] J. Molenda, D. Baster, M. U. Gutowska, a. Szewczyk, R. Puźniak, J. Tobola, Funct. Mater. Lett. 7 (2014) 144000
[3] J.Molenda, A.Milewska, W. Zajac, M.Rybski, J. Tobola, Phys. Chem. Phys. Chem. 19, (2017)25697
