3D interwoven MXene networks fabricated by the assistance of bacterial celluloses as high-performance cathode material for rechargeable magnesium battery

摘要

3D interwoven Ti3C2 MXene networks fabricated with the assistance of bacterial celluloses (BC) are used as a cathode material for rechargeable magnesium ion battery, which delivers an impressive specific capacity (171 mA h g(-1 )at 50 mA g(-1)) and good cycling performance (88% capacity retention after 100 cycles). In contrast, pure Ti3C2 film only shows a reversible capacity of less than 10 mA h g(-1) at 50 mA g(-1). Compared to pure Ti3C2 film (d = 1.4 nm), 3D interwoven Ti3C2 MXene networks (BC/Ti3C2 film) possess larger interlayer spacing (d = 1.8 nm), benefiting the magnesium migration, which is proved through DFT calculation. BC/Ti3C2 film with porous surface is observed through FESEM image. While for Ti3C2- film, all flakes stack together. As expected, the diffusion paths for magnesium ions are optimized in the BC/Ti3C2 film. Besides, Galvanostatic Intermittent Titration Technique shows a much larger magnesium diffusion coefficient of BC/Ti3C2 film than that of pure Ti3C2 film. Therefore, the larger interlayer spacing, optimized diffusion paths and larger magnesium diffusion coefficient contribute to the high electrochemical performance. Moreover, the working mechanisms of magnesium ion battery equipped with BC/Ti3C2 film are investigated. This work provides a new insight to design MXene-based cathode materials with high-performance.