Liquid Metal-Templated Tin-Doped Tellurium Films for Flexible Asymmetric Pseudocapacitors

Liquid metals can be surface activated to generate a controlled galvanic potential by immersing them in aqueous solutions. This creates energized liquid-liquid interfaces that can promote interfacial chemical reactions. Here we utilize this interfacial phenomenon of liquid metals to deposit thin films of tin-doped tellurium onto rigid and flexible substrates. This is accomplished by exposing liquid metals to a precursor solution of Sn2+ and HTeO2+ ions. The ability to paint liquid metals onto substrates enables us to fabricate supercapacitor electrodes of liquid metal films with an intimately connected surface layer of tin-doped tellurium. The tin-doped tellurium exhibits a pseudocapacitive behavior in 1.0 M Na2SO4 electrolyte and records a specific capacitance of 184.06 F center dot g-1 (5.74 mF center dot cm-2) at a scan rate of 10 mV center dot s-1. Flexible supercapacitor electrodes are also fabricated by painting liquid metals onto polypropylene sheets and subsequently depositing tin-doped tellurium thin films. These flexible electrodes show outstanding mechanical stability even when experiencing a complete 180 degrees bend as well as exhibit high power and energy densities of 160 W center dot cm-3 and 31 mWh center dot cm-3, respectively. Overall, this study demonstrates the attractive features of liquid metals in creating energy storage devices and exemplifies their use as media for synthesizing electrochemically active materials.

Automated summary

Liquid metals can be activated by immersing them in solutions to create energized liquid-liquid interfaces, promoting chemical reactions. This phenomenon is utilized to deposit tin-doped tellurium films onto substrates and fabricate supercapacitor electrodes. The tin-doped tellurium exhibits pseudocapacitive behavior and the flexible electrodes demonstrate excellent mechanical stability and high power and energy densities.