Role of surface terminations in enhancing CrTe₂ MXene performance for LIBs

The electrochemical performance of lithium-ion batteries (LIBs) is fundamentally governed by the intrinsic properties of the anode materials, particularly their charge storage capacity transport kinetics. In this study, we investigate the electronic and anodic characteristics of two-dimensional chromium telluride (CrTe₂) MXenes, specifically the surface-terminated CrTe₂X (X = O, S, F, and Cl) monolayers, using density functional theory (DFT) calculations. These edge terminations, commonly O, S, F, and Cl, naturally arise during MXene synthesis and significantly influence the material's electrochemical behavior. Our results reveal remarkably low lithium diffusion barriers, ranging from 0.29 to 0.37 eV across CrTe₂O, CrTe₂S, CrTe₂F, and CrTe₂Cl monolayers, indicating excellent charge/discharge kinetics. Additionally, the theoretical lithium storage capacities of CrTe₂O, CrTe₂S, CrTe₂F, and CrTe₂Cl are calculated to be 404.53 mAh.g^-1, 397.76 mAh.g^-1, 403.25 mAh.g^-1, and 396.36 mAh.g^-1, respectively. The corresponding open-circuit voltages (OCVs) are 0.79 V, 1.05 V, 0.85 V, and 0.98 V. These findings demonstrate that CrTe₂X MXenes possess significant potential as high-performance anode materials for next-generation LIBs, combining high capacity, fast ion transport, and favorable voltage profiles.