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.