Freestanding and Sandwich MXene-Based Cathode with Suppressed Lithium Polysulfides Shuttle for Flexible Lithium–Sulfur Batteries
Xiongwei Zhong, Dashuai Wang, Jinzhi Sheng, Zhiyuan Han, Chongbo Sun, Junyang Tan, Runhua Gao, Wei Lv, Xiaomin Xu, Guodan Wei, Xiaolong Zou, Guangmin Zhou
Abstract
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.