Abstract
Sulfur is an important electrode material in metal−sulfur batteries. It is usually coupled with metal anodes and undergoes electrochemical reduction to form metal sulfides. Herein, we demonstrate, for the first time, the reversible sulfur oxidation process in AlCl3/carbamide ionic liquid, where sulfur is electrochemically oxidized by AlCl4− to form AlSCl7. The sulfur oxidation is: 1) highly reversible with an efficiency of ~94%; and 2) workable within a wide range of high potentials. As a result, the Al−S battery based on sulfur oxidation can be cycled steadily around ~1.8 V, which is the highest operation voltage in Al−S batteries. The study of sulfur oxidation process benefits the understanding of sulfur chemistry and provides a valuable inspiration for the design of other high-voltage metal−sulfur batteries, not limited to Al−S configurations.
Highlights
Sulfur is an important electrode material in metal−sulfur batteries
We demonstrate, for the first time, the reversible sulfur oxidation in AlCl3/carbamide ionic liquid
We have demonstrated that sulfur can be electrochemically oxidized in ionic liquid with high reversibility
Summary
Sulfur is an important electrode material in metal−sulfur batteries It is usually coupled with metal anodes and undergoes electrochemical reduction to form metal sulfides. It is highly important to examine new redox pathways of sulfur to achieve viable applications of metal–sulfur batteries In this regard, sulfur oxidation is a worthy path because it can compensate the intrinsic low-voltage shortcoming of sulfur reduction. Due to the inert nature of sulfur, a high voltage needs to be applied to drive its electrochemical oxidation This is normally accompanied by electrolyte decomposition, leading to a poor reversibility[21,22,23]. The AlCl4− anions can oxidize sulfur to form aluminium sulfide chloride (AlSCl7), which can be reversibly reduced back to sulfur with a high efficiency of ~94% This oxidation–reduction process is workable within a wide range of high electrochemical potentials. This work sheds new light on the understanding of sulfur chemistry and presents sulfur oxidation as a new pathway to achieve the high-voltage applications of metal–sulfur batteries
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
