Interface engineering induced selenide lattice distortion boosting catalytic activity of heterogeneous CoSe2@NiSe2 for lithium-oxygen battery

The sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics greatly limit the development of lithium-oxygen (Li-O 2 ) batteries. Therefore, developing efficient electrocatalysts with high stability to boost oxygen involved reactions is particularly important for promoting the application of Li-O 2 batteries. Here, CoSe 2 @NiSe 2 heterostructure with distinct heterogeneous interfaces was fabricated via deliberate interface engineering. The formation of heterogeneous interface promotes local fine atomic array distortion that can act as an additional active site of ORR/OER. In addition, CoSe 2 @NiSe 2 with a distinct heterogeneous interface is favorable for the formation of built-in electric field during charging/discharging to enable electrodes with fast electrical transfer rates and reaction kinetics. Synergistically, the additional active sites brought by the fine atomic array distortion are highly conducive to the reversible formation and decomposition of the product. Undoubtedly, batteries with CoSe 2 @NiSe 2 exhibit excellent discharge/charge capacity (3530.1 mA h g −1 and 3485.6 mA h g −1 ), low overpotential (1.21 V) and excellent electrochemical stability for over 1200 h.