The synergistic effect of Lewis acidic etching V4C3(MXene)@CuSe2/CoSe2 as an advanced cathode material for aluminum batteries.

• The V 4 C 3 MXene composite bimetallic selenide heterostructure (V 4 C 3 @CuSe 2 /CoSe 2) was successfully prepared for the first time. • The initial discharge specific capacity of V 4 C 3 @CuSe 2 /CoSe 2 reached an impressive 809 mAh g⁻¹ at 1 A g⁻¹ and retained a substantial capacity of 169.1 mAh g⁻¹ after 3000 cycles. • DFT reveals that the strong metallic behavior of the heterostructure stemmed from the charge rearrangement facilitated by the bimetallic selenide structure and the optimization of the energy level structure. Herein, we focused on the development of the V 4 C 3 MXene composite bimetallic selenide heterostructure (V 4 C 3 @CuSe 2 /CoSe 2) as a cathode material for aluminum batteries. This heterostructure was prepared through a Lewis melt salt etching and selenization process. By capitalizing on the synergistic effect between the bimetallic selenide and V 4 C 3 MXene, V 4 C 3 @CuSe 2 /CoSe 2 exhibited rapid charge transfer and demonstrated superior discharge specific capacity compared to V 4 C 3 composite monometallic selenide. Furthermore, the incorporation of V 4 C 3 improved the material's stability during charging/discharging. The initial discharge specific capacity of V 4 C 3 @CuSe 2 /CoSe 2 reached an impressive 809 mAh g^–1 at 1 A g^–1. Even after nearly 3000 cycles, it retained a substantial capacity of 169.1 mAh g^–1. Ex-situ XPS analysis confirmed the reversible valence transitions of Cu, Co, and Se elements as the main energy storage reactions taking place in the cathode material. Density functional theory analysis provided further insights, revealing that the strong metallic behavior of the heterostructure stemmed from the charge rearrangement facilitated by the bimetallic selenide structure and the optimization of the energy level structure. Additionally, the presence of the bimetallic selenide structure significantly improved the adsorption efficiency of [AlCl 4 ]^–. Overall, this research contributes to the advancement of rechargeable aluminum ion batteries and presents a promising avenue for future developments in composite metal selenide structures and MXene-based materials. [Display omitted] [ABSTRACT FROM AUTHOR]