Development of aprotic lithium–oxygen (Li–O2) batteries suffers from slow cathode reaction kinetics, numerous side reactions, and large polarization, which are intimately related to the discharge product of Li2O2. Here, we designed and prepared a modified Co3O4 nanoparticle with atomic Ru substitution at octahedral Co sites supported by carbon nanocages (RuCoOx@HCNs) as a cathode catalyst. The asymmetrical octahedral Ru–O–Co units trigger a strong electron coupling effect, leading to charge redistribution and optimization of the d-orbital energy levels, thus facilitating oxygen activation and conversion into superoxide anions during discharging. More importantly, the Ru–O–Co units manifest high affinity for the intermediate LiO2, inducing the rapid formation of unique nanoneedle-like Li2O2 on RuCoOx@HCNs, avoiding the accumulation of byproducts and accelerating its decomposition during charge. These merit the Li–O2 battery with RuCoOx@HCNs to deliver a reduced polarization of 0.96 V and a prolonged lifespan of over 2200 h.
Li et al. (Thu,) studied this question.