A simple, efficient, fluorine–free synthesis method of MXene/Ti3C2Tx
anode through molten salt etching for sodium–ion batteries
Abstract
MXenes are mentioned in many applications due to their unique
properties. However, the traditional etching method has a long synthesis
time, dangerous process and high cost. Molten salt etching is not only
short in time, but also safe and simple, laying a good foundation for
industrialization. Here, we compare the traditional F–containing
etching method with the molten salt etching method. TEM elemental
mapping images and XPS show that the Ti3C2Tx surface end of traditional
etching is terminated by –F, while the Ti3C2Tx surface end of molten
salt etching is terminated by –Cl. Finally, the sodium–ion batteries
is fabricated and the performance difference of the three etching
methods is compared, the results show that the capacity of 102.1 mAh
g–1 can still be reached when the molten salt etching MXene material
returns to 0.1 A g–1 after the current density of 5 A g–1. After 500
cycles at 1 A g–1, there is no significant loss of capacity and the
coulomb efficiency is close to 100%. This work describes that molten
salt etching MXene has comparable sodium storage capacity to
conventional F–containing etched MXene, making it a potential candidate
for large–scale sodium–ion batteries production.