MOF-Derived Multi-Metal Sulfides with Optimized d-Band Center Enable Long-Term Stable Li–O ₂ Batteries

Rechargeable Li–O2 batteries (LOBs) attract considerable attention due to their ultrahigh theoretical energy density, exceeding the state-of-the-art lithium-ion batteries. However, obtaining LOBs with high efficiency and long cycle stability is difficult but crucial. To address this challenge, we employ an innovative synthesis strategy utilizing metal–organic frameworks (MOFs) as structural templates, developing a novel multimetal sulfide catalyst (CoNiFeS-2) through a sequential hydrothermal and calcination processes. This approach enables precise anchoring and uniform distribution of metal ions, yielding a catalyst with optimal elemental composition and abundant crystalline–amorphous heterointerface, which provides additional active sites. Through systematic optimization of Fe addition contents, the CoNiFeS-2-based cathode demonstrates remarkable electrochemical performance of LOBs: a high reversible capacity of 16,446.5 at 200 mA g–1, stable cycling over 237 cycles with a limited capacity of 1000 mAh g–1, and the cathode even sustains over 447 cycles with a cutoff specific capacity of 500 at 1000 mA g–1. Additionally, the outstanding rate performance demonstrates that the CoNiFeS-2 catalyst synergistically integrates high catalytic activity and rapid ion/electron transfer. These advancements significantly enhance the performance of LOBs and clarify the influence of structure/composition on activity, offering new insights into the design of highly efficient electrocatalysts for next-generation energy storage systems.