Coupling interface constructions of hollow Co-Mo mixed multiple oxidation states heterostructure for high-performance aprotic Li-O₂ battery

Constructing interfaces in heterostructures is effective for modulating the electronic properties of electrocatalysts. The hollow CoMoO₄–Co₃O₄ heterostructure (HCMCH) was prepared as a bifunctional electrocatalyst for Li-O₂ battery. The different components in CoMoO₄–Co₃O₄ heterostructure presented the efficient coupling and enhanced the electrocatalytic activity for aprotic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), in which it improved the obviously reduced overpotential of 300 mV (compared with the pure Ketjen black (KB) electrode), enhanced reversibility of 80% capacity retention after 6 full cycles and the superior cyclability of more than 200 cycles with an optimized strategy. The battery performance of the HCMCH was not only associated with the unique hollow structure and rich active sites but also with coupling interface constructions synergetic effects attaching to the improving conductivity and optimized the discharge conversion. These results suggested that this HCMCH electrocatalyst was a promising candidate for the Li-O₂ battery and it gave a novel insight for high performance electrocatalyst designing.