Interfacially engineered induced nickel-based heterostructures as efficient catalysts for Li-O2 batteries

Abstract

Lithium-oxygen batteries have much attracted attention due to their ultra-high theoretical energy density. However, its practical application is still hampered by many issues, which are mainly attributed to the slow kinetics of oxygen redox reaction/oxygen evolution reaction (ORR/OER) dynamics. Aimed to this issue, in this work, NiO nanosheets loaded on carbon cloth (NiO/CC) were first synthesized, and then the Se@NiO/CC heterostructure was obtained by selenization. The synthesized Se@NiO/CC with distinct heterointerface is beneficial to form a built-in electric field during charge/discharge process, which endows the cathode with a fast charge transfer rate and reaction kinetics. Furthermore, the formation of heterointerfaces facilitates the deformation of localized fine atomic arrays, which can serve as additional active sites for ORR/OER. Experimental and theoretical results show that the heterogeneous interface of NiO and NiSe can adjust the adsorption energy of intermediate LiO2 and optimize the morphology of the discharge product. The interaction between Se@NiO/CC and the intermediate during discharge/charge is conducive to electron transfer. The round-trip efficiency, cycle stability and discharge capacity of Li-O2 batteries are greatly improved thanks to the synergistic effect of heterostructures.