Effect of Combination Model of MoTe₂ and MXene Layers on Sodium Ion Storage.

Abstract

The integration of different crystal planes between two-dimensional (2D) materials results in various combinations, which always exert different effects on the electrochemical properties of materials. The metallic 1T' phase of molybdenum telluride is a promising anode for sodium-ion batteries (SIBs), but its rearrangement and restacking during charge/discharge process causes a decline in cycle. Herein, MX@MoTe₂-P with MoTe₂ (002) planes parallel to MXene layers and MX@MoTe₂-V with MoTe₂ (002) planes perpendicular to MXene layers are controllably constructed. Compared with MX@MoTe₂-V, the new interface formed between MoTe₂ and MXene in MX@MoTe₂-P has a stronger van der Waals interaction and larger contact area, helpful to store more sodium ions and contributing to its excellent structural stability and battery capacity. Although MX@MoTe₂-V has a higher sodium adsorption energy than MX@MoTe₂-P, the small interface area lowers the storage capacity and it further aggravates the collapse of the structure. When used as the anode for SIBs, MX@MoTe₂-P offers excellent cycle stability and specific capacity. In particular, sodium-ion full cell consisting of MX@MoTe₂-P anode and Na₃V₂(PO₄)₃ cathode shows the excellent performance (147.2 mAh g^-1@1000 cycles at 5 A g^-1) surpassing all the reported MoTe₂-based materials. This work provides a guide for the manufacture of new electrode materials.