Enhanced Li-O₂ battery performance using NiS/MoS₂ heterostructure by building internal electric field to promote the...

Electrocatalysts with appropriate electron coupling toward LiO₂ intermediates can exhibit superior oxygen reduction/evolution reaction kinetics in Li-O₂ batteries (LOBs). In this work, a charge redistribution strategy has been developed by constructing NiS/MoS₂ heterostructure nanosheet self-assembled hollow microspheres with an internal electric field to regulate the interaction with LiO₂ and then improve the electrochemical performance of LOBs. Density functional theory calculations and physicochemical characterizations reveal that the difference of work functions between NiS and MoS₂ promotes the electron redistribution in heterointerface via built-in electrical field, leading to increased electron density of interfacial Ni atom, thereby enhancing its electron coupling toward LiO₂ intermediates and promoting one-electron oxygen reduction/oxidation reaction kinetics. As a result, the NiS/MoS₂-based LOBs exhibit evidently higher discharge capacity and much better cycling performance than the batteries using NiS and MoS₂. This work provides a reliable charge redistribution strategy induced by build-in electric field to design efficient catalysts for LOBs.