Ferromagnetic two-dimensional Fe₃GaTe₂ and Ni-doped Fe₃GaTe₂ as electrocatalysts for lithium-sulfur batteries: a...

Li-S batteries are regarded as next-generation energy storage solutions due to their exceptional theoretical capacity. However, their practical application is hindered by the shuttling effects of lithium polysulfides (LiPSs) and the sluggish decomposition of Li₂S. Addressing these challenges necessitates the development of effective catalysts that can accelerate the conversion of LiPSs and enhance the performance of Li-S batteries. In this study, we investigated the electrocatalytic activity of two-dimensional ferromagnetic Fe₃GaTe₂ and Ni-doped Fe₃GaTe₂ in Li-S batteries using first-principles calculations. Our findings indicate that these materials exhibit optimal binding strengths (ranging from 1.03 to 1.45 eV) with long-chain LiPSs, effectively preventing their dissolution into the electrolyte. Furthermore, we demonstrate remarkable catalytic activity during the sulfur redox reaction (SRR), with the ΔG of only 0.54 eV for Ni-doped Fe₃GaTe₂. The reduced energy barrier induced by Fe₃GaTe₂ and Ni-doped Fe₃GaTe₂ significantly accelerates the charge/discharge kinetics of Li-S batteries. Furthermore, the Ni-doped Fe₃GaTe₂ demonstrates an increase in binding energy, alongside a decrease in Gibbs free energy in the rate-determining step and activation energy barrier, collectively enhancing its catalytic performance. We conducted an in-depth analysis from the perspectives of magnetic moment and p-band theory. This theoretical work contributes to a better understanding of the application of ferromagnetic materials in the Li-S battery domain, paving the way for advanced high-efficiency energy storage solutions.