Investigation on TiS2 electrode material for intercalation batteries, namely Li, Na, Mg, Al, K, Ca, and Zn -ion cells: A DFT study
Sepideh Safaeipour, Mohammad Mahdi Kalantarian, Mohsen Ostad Shabani, A. Faeghinia
Abstract
This paper analytically evaluates LiTiS2, NaTiS2, MgTiS2, AlTiS2, Al0.5TiS2, KTiS2, CaTiS2, and ZnTiS2 electrode materials, via DFT calculations, to use in Li-, Na-, Mg-, Al-, K-, Ca-, and Zn- ion intercalation batteries. The structural properties and stability, electrochemical, and electrical properties are investigated. For each battery, one (and two for Al-ion) intercalated structure alongside with two deintercalated structures are assessed, for the first and other cycles separately. Two approximation methods, GGA and GGA + U, are performed; which, three values of U (i.e. 2.1, 3.5, and 5.5) are taken into account. Structural parameters, internal and Fermi energies, DOS, band structure, and electron density are evaluated. Novel approaches are used for voltage, band-gap, and rate-capability; in which, for each property, two approaches are considered, namely, Fermi/Internal-energy, ILBG/ELBG, and Delta/CCTB, respectively. Our results show that K- and Ca- ion cells may face some challenges regarding electrical rate-capability and structural stability. Furthermore, the paper depicts that TiS2 electrode can represent superior properties for some intercalation batteries. It performs a comprehensive theoretical investigation on the layered TiS2 electrode material to comprehend its behaviour/properties, broadening insights for assessing different intercalation batteries.