TiSe2 as a Cathode for Multivalent Ion Batteries

To drive large scale energy storage, it is imperative to investigate the properties of multivalent ion batteries (MVIBs). TiSe₂ cathodes experience electron delocalization in metal-ligand units, a trait shown to improve battery performance. Both TiSe₂ and the Chevrel phase (CP) experience d-p orbital hybridization, suggesting TiSe₂ may demonstrate similar MVIB performance to the CP, an established MVIB cathode. TiSe₂ has been previously studied with a Mg anode, though it was not studied with other multivalent metals, in particular Ca, which has demonstrated superior performance to Mg in some respects. In this computational study, we investigate the intercalation of TiSe₂ with several mono/multivalent ions from the following metal anodes: Li, Na, Mg, Ca, Zn, and Al (with a particular focus on Ca-ion). We used density functional theory methods, including the SCAN functional, to calculate the average voltages for the aforementioned metals paired with TiSe₂. We consider other crucial battery properties, including volume change, diffusion kinetics, material characterization, and stability.