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

Although RuO2 is a potential electrocatalyst for Li-O-2 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.