The synergistic effect of Lewis acidic etching V_(4)C_(3)(MXene)@CuSe_(2)/CoSe_(2) as an advanced cathode material for aluminum batteries

Herein,we focused on the development of the V_(4)C_(3) MXene composite bimetallic selenide heterostruc-ture(V_(4)C_(3)@CuSe_(2)/CoSe_(2))as a cathode material for aluminum batteries.This heterostructure was pre-pared 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 Ag^(-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 reac-tions 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 rearrange-ment 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 ef-ficiency of[AlCl4]^(-).Overall,this research contributes to the advancement of rechargeable aluminum ion batteries and presents a promising avenue for future developments in composite metal selenide struc-tures and MXene-based materials.