Interfacial electric field Intensification through Defect-Tuned work function engineering for advanced aluminum batteries

Heterostructures facilitate the generation of the interfacial electric field (IEF) that enhances charge transfer and ion diffusion, resulting in improved electrochemical performance in rechargeable aluminum batteries (RABs). However, the ability of heterostructures to generate the IEF is limited, and research efforts on IEF modulation remain scarce, particularly in the field of RABs. Herein, sulfur (S) vacancies are introduced into the core–shell MoS 2 /ZnS heterostructure (Vs-MoS 2 /ZnS) to strengthen the IEF and enhance aluminum storage performance. First-principles computational analyses demonstrate S vacancies increase the work function difference, induce spontaneous interfacial charge transfer, and enhance the IEF. The increased IEF accelerates electron transport, reduces ion diffusion barriers, and increases the adsorption capacity of charge carriers, significantly improving the reaction kinetics of RABs. Moreover, the designed core–shell structure, together with S vacancies, provides strong structural integrity and numerous active sites to the host material. Benefiting from these merits, the Vs-MoS 2 /ZnS cathode demonstrates enhanced reversible capacity (220 mAh g −1 at 0.5 A g −1 ) and long-term cycling stability (127 mAh g −1 over 2000 cycles at 4.0 A g −1 ). This work provides an effective approach for designing heterostructures by modulating the IEF, offering novel insights into the development of advanced RABs cathodes.