Flexible aqueous Zn–S battery based on an S-decorated Ti3C2Tx cathode

Abstract

Flexible aqueous zinc-ion batteries can store energy safely and at a low cost, which benefits wearable electronic gadgets; however, currently used cathodes restrict these devices with a low specific capacity and energy density. Herein, we developed a flexible zinc-sulfur (Zn–S) battery constructed by Ti3C2Tx decorated with sulfur (S@Ti3C2Tx) as a cathode and Zn metal anode with iodine-added amphiphilic gel electrolyte (AGE). Benefiting from the confinement synergy of S@Ti3C2Tx cathode, the Zn-S battery exhibited a high storage capacity of 772.7 mAh g−1 at 300 mA g−1, which is higher than a conventional S-decorated carbon cathode (491.7 mAh g−1). More specially, the flexible device offers good cycling stability (82.7%) and excellent mechanical stability with 91% capacity retention after 90° bending (500 cycles). To demonstrate real applications, the flexible Zn–S batteries were integrated in series to power electrical gadgets (e.g., digital clock, light-emitting diode, and robot). It exhibits exceptional flexibility to sustain different deformations and maintains a steady supply of power to run the wearable electronic gadget. These findings offer a fresh starting point for flexible energy storage technologies and show the promising potential of the Zn–S battery in real-world applications.