MoS2 and WSe2 monolayers as anode materials for future Li, Na, and K ion batteries under electric field effect

The performance of rechargeable ion batteries (IBs) is often limited by power and energy density. However, lithium, sodium, and potassium-ion batteries (IBs) are gaining significant attention due to their potential in energy storage applications. Despite this, finding suitable anode materials remains a challenge. In this study, we perform a first-principles investigation of MoS2 and WSe2 monolayers as anode materials for Li, Na, and K-ion batteries. We analyze the adsorption energies and diffusion behaviors of these ions within the monolayers to assess their potential as anodes. Our calculations reveal that lithium ions exhibit outstanding adsorption properties, while sodium and potassium ions demonstrate exceptional and low diffusion barriers on both MoS2 and WSe2 monolayers, enabling unhindered ion migration. To further facilitate Li-ion diffusion, applying an external electric field (ranging from 0 to 0.8 V/& Aring;) significantly reduces the energy barriers, thereby enhancing the charging rate of Li-ion batteries. The present research demonstrates that MoS2 and WSe2 monolayers exhibit exceptional storage capacities of 1674.32 mAh/g, 1339.46 mAh/g, and 334.86 mAh/g for Li, Na, and K on MoS2, and 627.36 mAh/g and 156.84 mAh/g for Li, Na and K on WSe2, respectively, all achieved at low voltages. These findings suggest the potential of MoS2 and WSe2 monolayers as high-capacity, fast-charging anode materials for Li/Na/K ion batteries.