Highly Conductive and Stable Two-Dimensional WC<sub>4</sub> Acting as an Efficient Anode Material for Alkali-Metal Ion Batteries: Insight from DFT
Javed Rehman, Tong Yu, Adel El‐marghany, Mohamed F. Shibl, Guochun Yang
Abstract
Extensive studies have been carried out on two-dimensional (2D) metal carbides (MCs) as prospective nominees for alkali-metal ion batteries (AMIBs). These materials have attracted interest because of their substantial specific surface area, enabling them to accommodate a large quantity of metal ions along with their excellent diffusivity. However, the high metal content in these materials results in strong Coulomb’s repulsive interactions with Li/Na/K ions, leading to a low storage capacity. To tackle this challenge, we have adjusted the carbon composition in 2D WC 4 to enhance its storage capacity and mitigate the repulsive forces between W and Li/Na/K ions. Our computational analysis has revealed that the WC 4 monolayer maintains dynamic and thermal stability, with a robust cohesive energy that supports its experimental synthesis. The WC 4 monolayer, as an anode material, exhibits high electronic conductivity and diffusivity and rapid ion transfer rate, as verified by low activation energy barriers of 0.55 eV for Li-ion batteries (LIBs), 0.084 eV for Na-ion batteries (SIBs), and 0.081 eV for K-ion batteries (PIBs), which facilitate robust charging and discharging processes. Additionally, the average voltages calculated for Li-, Na-, and K-ion batteries are 0.65, 0.46, and 0.42 V, respectively. Consequently, the WC 4 monolayer demonstrates impressive Li, Na, and K storage capacities, reaching 577, 462, and 462 mA h g –1, respectively, for maximum loading. These results demonstrate that 2D WC 4 as a promising anode material for alkali-ion batteries.