Freestanding and Sandwich MXene-Based Cathode with Suppressed Lithium Polysulfides Shuttle for Flexible Lithium-Sulfur Batteries

Flexible lithium-sulfur (Li-S) batteries with high mechanical compliance and energy density are highly desired. This manuscript reported that large-area freestanding MXene (Ti3C2Tx) film has been obtained through a scalable drop-casting method, significantly improving adhesion to the sulfur layer under the continuously bent. Titanium oxide anchored on holey Ti3C2Tx (TiO2/H-Ti3C2Tx) was also produced by the well-controlled oxidation of few-layer Ti3C2Tx which greatly facilitates lithium ion transport as well as prevents the shuttling of lithium polysulfides. Therefore, the obtained sandwich electrode has demonstrated a high capacity of 740 mAh g(-1) at 2 C and a high capacity retention of 81% at 1 C after 500 cycles. Flexible Li-S batteries based on this sandwich electrode have a capacity retention as high as 95% after bending 500 times. This work provides effective design strategies of MXene for flexible batteries and wearable electronics.

Automated summary

This paper reports a method of preparing large-area MXene film through drop-casting, and using this film to improve the adhesion and capacity retention of lithium-sulfur batteries. At the same time, titanium oxide anchored on MXene was prepared by oxidation treatment, which further promotes lithium ion transport and prevents the shuttle effect of lithium polysulfides.