First-principles calculations of bulk WX₂(X = Se, Te) as anode materials for Na ion battery

Two-dimensional transition metal dichalcogenides are promising anode materials for Na ion batteries (NIBs). In this study, we carried out a comprehensive investigation to analyze the structural, electrochemical characteristics, and diffusion kinetics of bulk WX₂(X = Se, Te) by employing first-principles calculation in the framework of density functional theory. We deeply studied the full intercalation of Na⁺in WX₂and diagnosed NaX phase through conversion reaction mechanism. The voltage range of 2.05-0.48 V vs Na/Na⁺for NaWSe₂and 2.26-0.65 V for NaWTe₂(y= 0-3) have been noted. Density of states analysis showed metallic behavior of WX₂(X = Se, Te) during sodiation. The facile pathways for Na⁺mobility through WX₂have shown that tungsten dichalcogenides are inferred as excellent electrode material for NIBs.