Metal sulfide heterojunction with tunable interfacial electronic structure as an efficient catalyst for lithium-oxygen batteries

The design and preparation of catalysts with excellent stability and high activity are critical to improving the performance of lithium-oxygen (Li-O 2 ) batteries. Heterostructural catalysts have attracted wide attention due to their tunable structure and effectiveness in promoting oxygen reduction reaction and oxygen evolution reaction kinetics. In this study, CuCo 2 S 4 /CoS 1.097 polymetallic sulfides were proposed as effective electrocatalysts toward oxygen electrode reactions in Li-O 2 batteries. Density functional theory calculations demonstrated that the electronic structure of CuCo 2 S 4 /CoS 1.097 was regulated at the heterogeneous interface, which was beneficial for optimizing the adsorption of intermediates during the reaction, eventually accelerating the sluggish kinetics of oxygen electrode reactions. The CuCo 2 S 4 /CoS 1.097 -based Li-O 2 batteries exhibited a high specific capacity of 26,727.8 mAh g −1 and an outstanding durability of over 267 cycles at 100 mA g −1 . This study provides a new perspective on the design and application of excellent cathode materials in Li-O 2 batteries.