Constructing NiCo₂Se₄/NiCoS₄ heterostructures for high-performance rechargeable aluminum battery cathodes

Rechargeable aluminum batteries (RABs) are regarded as promising candidates for new-generation rechargeable batteries. However, due to the high charge density of Al³⁺, the modest cycling performance of RABs is difficult to improve, given the strong coulombic interaction between Al³⁺ and host materials. Heterostructure engineering is emerging as a promising strategy to further enhance the electrochemical performance of energy storage devices. Herein, heterostructured NiCo₂Se₄/NiCoS₄ prepared via a two-step solvothermal treatment is reported as a new type of RAB cathode material. As expected, the heterostructured NiCo₂Se₄/NiCoS₄ cathode delivers a discharged specific capacity of 112 mA h g⁻¹ over 195 cycles. It is instructive to note that the operational mechanism of the RABs is the intercalation of Al³⁺ and the redox process of Co, Ni, and S elements.