First-Principles Investigation of 2D o-Al2C2 Monolayer: A High-Performance Anode for Li/Na-ion Batteries.

Abstract

Development of novel anode materials with superior electrochemical performanceis imperative for advancing next-generation high-performance recharge able batteries beyond current limitations. In this study, we present a 2D o-Al2C2 monolayer as a promising lightweight candidate for lithium and sodium-ion battery systems, based on the density functional theory (DFT) investigations and ab initio molecular dynamics (AIMD) simulations. Our comprehensive investigation demonstrates that the o-Al2C2 monolayer ex-hibits remarkable stability with a cohesive energy of -5.30 eV/atom and maintains its structural integrity at room temperature during extended AIMD simulations. The o-Al2C2 monolayer demonstrates exceptional electrochem ical characteristics for Li and Na storage: theoretical specific capacities of 3780.42 mA.h.g-1 and 3436.75 mA.h.g-1, optimal average open circuit volt ages of 0.81 V and 0.67 V, and favorable diffusion barriers of 0.62 eV and 0.31 eV, respectively. These performance metrics significantly surpass those of conventional graphite (372 mA.h.g-1) and other recently reported 2D anode materials, establishing o-Al2C2 as an exceptionally promising candidate for next-generation energy storage applications. Hence, this current theoretical investigation suggests that the o-Al2C2 monolayer holds significant potential for future experimental studies in lithium and sodium storage applications for LIB and NIB systems.