Unraveling the Effects of Al Doping on the Electrochemical Properties of LiNi0.5Co0.2Mn0.3O2 Using First Principles. Issue 1 (1st January 2017)

• Record Type: Journal Article
• Authors: Dixit, Mudit; Markovsky, Boris; Aurbach, Doron; Major, Dan T.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 1(2017)
• Page Start: A6359
• Page End: A6365
• Publication Date: 2017-01-01
• Subjects: Al Doping -- Cathode materials -- COHP -- DFT calculations -- Doping -- NCM -- Ni-rich NCM; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0561701jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : One of the prevailing approaches to tune properties of materials is lattice doping with metal cations. Aluminum is a common choice, and numerous studies have demonstrated the ability of Al 3+ doping to stabilize different positive electrode materials, such as Li[Ni-Co-Mn]O2 (NCMs). Currently, an atomic level understanding of the stabilizing effect of Al doping in NCMs is limited. In this work, we investigate the effect of Al doping on Ni-rich-NCM-523 (LiNi0.5 Co0.2 Mn0.3 O2 ). Our results suggest that Al stabilizes the structure of the cathode material via strong Al-O iono-covalent bonding due to a significant Al(s)-O(p) overlap, as well as significant charge transfer capabilities of Al. The calculated formation energies suggest that Al doping results in stabilization of partially lithiated states of NCM-523. On the other hand, calculated voltages indicate only a minor change in the voltage profiles as a function of the state-of-charge due to Al doping, and a modest increase in the Li diffusion barrier was observed. We note that high doping concentrations might mitigate the Li diffusion rates.