High-Performance Rechargeable Aluminum-Selenium Battery with a New Deep Eutectic Solvent Electrolyte: Thiourea-AlCl₃

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aluminum-sulfur batteries (ASBs) show promise but suffer from rapid capacity decay due to sluggish reactions and electrolyte side reactions.
• Traditional ASBs face limitations in cycling performance, hindering practical applications.

Purpose of the Study:

• To develop high-performance rechargeable aluminum-selenium batteries (ASeBs) overcoming the limitations of ASBs.
• To investigate novel electrolyte and cathode materials for improved battery kinetics and stability.

Main Methods:

• Fabrication of selenium nanowires on carbon cloth (Se NWs@CC) via low-temperature selenization.
• Utilization of a thiourea-AlCl3 deep eutectic solvent as the electrolyte.
• Electrochemical characterization including cycling tests and ex situ analyses (Raman, XRD, XPS).

Main Results:

• Achieved a high specific capacity of 260 mAh g⁻¹ at 50 mA g⁻¹.
• Demonstrated long cycling life of 100 cycles with 93% Coulombic efficiency at 100 mA g⁻¹.
• Proposed a working mechanism based on reversible Al-Se alloying, confirmed by advanced characterization.

Conclusions:

• Successfully developed stable and high-capacity rechargeable aluminum-selenium batteries.
• The novel electrolyte and cathode design significantly enhance battery performance.
• This research offers insights into aluminum-chalcogenide batteries for future energy storage.