Binder-free S@Ti3C2Tx sandwich structure film as a high-capacity cathode for a stable aluminum-sulfur battery

The rechargeable aluminum-sulfur (Al-S) battery is a promising alternative-energy storage device with high energy density and made of cheap raw materials. However, Al-S batteries face several obstacles, especially the shuttle effect. Herein, a binder-free S@Ti3C2Tx sandwich structure film with uniform sulfur dispersion was designed. The two-dimensional (2D) layered material Ti3C2Tx not only has the function of binder and conductive agent but also is a promising host for sulfur anchoring. As a result, S@Ti3C2Tx film showed an initial capacity of 489 mA h at 300 mA and retained the value at 415 mA h g(-1) after 280 stable cycles, with an average Cou- lombic efficiency of -95%. The film displayed higher capacity and stability than the S + Ti3C2Tx cathode prepared by the slurry-coating method (the initial capacity was 317 mA h g(-1 )and then decayed to 222 mA h g(-1 )after 160 cycles). The main capacity of S@Ti3C2Tx film in the Al-S battery came from the reversible redox reaction of S2- and S. This new 2D material combined with a controllable electrode structure design paves the way for the development of Al-S batteries.

Automated summary

A binder-free S@Ti3C2Tx sandwich structure film was designed to address the shuttle effect in aluminum-sulfur batteries. The film exhibited uniform sulfur dispersion and higher capacity and stability, paving the way for the development of these batteries.