Aluminene as a Low-Cost Anode Material for Li- and Na-Ion Batteries

Two-dimensional (2D) materials are promising candidatesfor next-generationbattery technologies owing to their high surface area, excellent electricalconductivity, and lower diffusion energy barriers. In this work, weuse first-principles density functional theory to explore the potentialfor using a 2D honeycomb lattice of aluminum, referred to as aluminene,as an anode material for metal-ion batteries. The metallic monolayer shows strong adsorption for a range of metal atoms, i.e., Li, Na,K, and Ca. We observe surface diffusion barriers as low as 0.03 eV,which correlate with the size of the adatom. The relatively low averageopen-circuit voltages of 0.27 V for Li and 0.42 V for Na are beneficialto the overall voltage of the cell. The estimated theoretical specificcapacity has been found to be 994 mA h/g for Li and 870 mA h/g forNa. Our research highlights the promise of aluminene sheets in thedevelopment of low-cost, high-capacity, and lightweight advanced rechargeableion batteries.