Ultrafast kinetics net electrode assembled via MoSe2/MXene heterojunction for high-performance sodium-ion batteries

Abstract

Establishing advanced sodium-ion batteries (SIBs) with high energy density and eco-friendly electrode materials are still far from satisfactory due to the large-size of sodium-ions and sluggish redox kinetics during electrochemical processes. Herein, a novel ultrafast kinetics net electrode assembled via MoSe2/MXene heterojunction is synthesized by a simple hydrothermal method followed by thermal annealing. Featuring the Van der Waals force interaction between MoSe2 and MXene, the volumetric change during the sodium ions insertion/extraction courses is effectively restrained, and the reaction kinetics is greatly enhanced further. Meanwhile, both the high electrical and ion conductivity (lower diffusion barrier between Na+/MXene ~0.066 eV) provided by the unique MXene based net heterostructure of our hybrid materials, as evidenced by DFT calculations, are beneficial to the transportation of sodium ions, thus enabling an outstanding rate and long-cycling capability. As a result, the fabricated cells exhibit high reversible capacities of 490 mAh g−1 at 1 A g−1, as well as 250 mAh g−1 at a high current of 10 A g−1 with a coulombic efficiency of 99.8%, indicating the excellent electrochemical performance of our hybrid materials, especially at high current. This novel net MoSe2/MXene heterostructure, combined with our simple synthesis strategy together, are expected to have great potential in sodium-ions storage application.