Finding an appropriate new anode material with high electrochemical performance for lithium-ion batteries (LIBs) is considered one of the significant challenges for both the academic and industrial research communities. Herein, we propose to explore the efficiency of a newly designed two-dimensional (2D) material, named orthorhombic dialuminium dinitride (o-Al2N2), as an alternative anode material for LIB systems through first-principles calculations and ab initio molecular dynamics (AIMD) simulations. The obtained results show that orthorhombic-Al2N2 exhibits a high specific capacity of 1144.2913 mAhg−1, an operating voltage around 0.575 V, and a low kinetic diffusion barrier of 0.26 eV. These results prove the suitability of the o-Al2N2 monolayer as a promising anode material for LIBs with high structural stability, strong binding energy towards lithium adsorbent, fast lithium diffusion, and a high theoretical capacity. These features rank the 2D o-Al2N2 monolayer among the best choices for the anode part of the next-generation rechargeable LIBs.