Two-dimensional Janus MoSSe as a potential anode material for Na/K-ion batteries: A theoretical study

Using first-principles methods, we have investigated the adsorption and diffusion of Na and K over Janus MoSSe for Na/K-ion batteries (NIBs/KIBs) anodes. The optimized adsorption energies were found to be 1.66 eV for Na and 2.18 eV for K which are sufficiently large to ensure stability and safety during operation. In addition, Janus MoSSe yields a high storage capacity of 510 mAh/g and 203 mAh/g, respectively. Additionally, Janus MoSSe has low diffusion barriers 0.075 and 0.058 eV for Na and K, respectively. Given these advantages, we conclude that the Janus MoSSe can be considered as an excellent candidate for anodes in NIBs/KIBs.