The mechanism of Li-O2 batteries is based on the reactions of lithium ions and oxygen, which hold a theoretical higher energy density of approximately 3500 W h kg-1. In order to improve the practical specific capacity and cycling performance of Li-O2 batteries, a catalytically active mechanically robust air cathode is required. In this work, we synthesized a freestanding catalytic cathode with RuO2 decorated 3D web Co3O4 nanowires on nickel foam. When the specific capacity was limited at 500 mA h g-1, the RuO2-Co3O4/NiF had a stable cycling life of up to 122 times. The outstanding performance can be primarily attributed to the robust freestanding Co3O4 nanowires with RuO2 loading. The unique 3D web nanowire structure provides a large surface for Li2O2 growth and RuO2 nanoparticle loading, and the RuO2 nanoparticles help to promote the round trip deposition and decomposition of Li2O2, therefore enhancing the cycling behavior. This result indicates the superiority of RuO2-Co3O4/NiF as a freestanding highly efficient catalytic cathode for Li-O2 batteries.
This journal is © The Royal Society of Chemistry.