Screening Cobalt-Containing Supports for RuO₂ to Enhance Cycling Stability in Li-O₂ Batteries

Although RuO₂ is a potential electrocatalyst for Li-O₂ batteries (LOBs), its high price limits its large-scale application. Recent reports suggest that combining small amounts of RuO₂ with nonprecious supports is a wise choice for developing low-cost bifunctional electrocatalysts. Here, a series of cobalt-containing supports, including Co₃O₄, Co-NCNTFs, and NiCo₂O₄, are designed to support RuO₂ to explore their electrocatalytic performance in LOBs. Among them, RuO₂@NiCo₂O₄ exhibits significantly better catalytic activity and stability compared to the RuO₂@Co₃O₄ and RuO₂@Co-NCNTF counterparts. Notably, RuO₂@NiCo₂O₄ achieved a low overpotential of 0.51 V and exceptional long-term reversibility exceeding 2000 h at a capacity limit of 1000 mAh g^-1 with a current density of 500 mA g^-1, suggesting that the electronic conductance, microstructure, and electrochemical stability of the support are crucial factors in designing RuO₂-based electrocatalysts for LOBs. This research provides valuable insights into designing cost-effective and efficient catalysts for advancing energy storage technologies.