Decoding the long-term cyclic evolution of lithium-sulfur batteries via tailored Mo_1−xRe_xS₂ nanosheets

Lithium-sulfur batteries (LSBs) are of great promise for next-generation energy storage systems due to the ultra-high theoretical energy density. However, the desired LSBs performance are usually restricted by the shuttle effect of polysulfides and their limited sulfur redox kinetics. With this regard, we have synthesized high-concentration Mo-doped ReS₂ nanosheets to promote the cathode reaction kinetics and anode interface stability. The composite cathode provides extraordinary cycle durability, maintaining a capacity of 864.01 mAh g⁻¹ after 1000 cycles at 1 C (capacity attenuation per cycle: 0.0023 %). The density functional theory (DFT) simulations indicated that the atomic- scale heterogeneous interfaces synergically weaken S-S bonds in Li₂S₄ and reduce Li₂S decomposition barriers, which are essentially beneficial to accelerate solid-liquid-solid phase transitions. This research not only paves a viable pathway for designing multifunctional electrocatalysts, but also greatly prompts their practical applications in next-generation metal sulfur battery systems with stable cycle life and fast sulfur redox kinetics.