MXene/Borophene Heterostructures: Mechanistic Insights into Cathode Stability and Capacity in Aluminum‐Ion Batteries

The development of Aluminum dual‐ion batteries (ADIBs) is hindered by the structural instability and limited capacity of cathode caused by AlCl 4 intercalation. A deeper understanding of cathode‐anion interactions and the fundamental reaction mechanisms is necessary to address these challenges. Herein, MXene‐borophene, V 2 CT x /B heterostructures are proposed as high‐performance cathodes for ADIBs, which combines the high electronic conductivity and tunable surfaces of MXenes with the mechanical strength and effective charge transport properties of borophene. First‐principles calculations show that AlCl 4 adsorption in V 2 CT x /B heterostructures is significantly stronger than in pristine V 2 CT x and B monolayers and the low diffusion barrier of V 2 CO 2 /B (0.31 eV) allows rapid charge/discharge kinetics. With a large storage capacity of 232 mAh g −1 , voltage profile exhibits an average working voltage of 1.73 V therefore emphasizing their applicability. Moreover, Ab initio molecular dynamics (AIMD) simulations verify the thermodynamic stability of the heterostructure under operating conditions. These results highlight the V 2 CO 2 /B heterostructure as a potential cathode that provides significant understanding of AlCl 4 intercalation mechanisms and helps the systematic development of next‐generation aluminum‐based energy storage devices.