Magnesium polysulfide catholyte (MgSx): Synthesis, electrochemical and computational study for magnesium-sulfur battery application
Abstract
Rechargeable magnesium-sulfur (Mg/S) batteries are considered a promising energy storage devices for grid-scale applications due to their high theoretical energy density, safety, and low cathode cost. However, the Mg/S batteries suffer from the low practical energy density mainly arising from the rapid dissolution of polysulfides and slow reaction kinetics between Mg and solid-phase sulfur. In this regard, we have introduced here the magnesium polysulfide (MgSx) catholyte as a liquid-phase active material to conquer the sluggish redox kinetics of Mg/S batteries. A polyaniline-coated carbon cloth (CC@PANI) has been incorporated as a current collector and a reservoir for magnesium-polysulfide(MgSx) catholyte. The MgSx containing CC@PANI cathode (i.e., CC@PANI@MgSx cathode) exhibits an initial reversible specific capacity of 514 mA h g-1 and retains 428 mA h g-1 after 25 cycles. The effect of MgSx catholyte on the electrochemical performance of the Mg/S batteries have been closely investigated through post-cycling characterization of Mg anode and computational studies. Besides, the phase transition of sulfur during magnesiation a complete reaction has been studied in the current report.
- Publication:
-
Journal of Power Sources
- Pub Date:
- February 2021
- DOI:
- 10.1016/j.jpowsour.2020.229326
- Bibcode:
- 2021JPS...48629326M
- Keywords:
-
- Magnesium-polysulfide catholyte;
- Magnesium-sulfur batteries;
- DFT study;
- Polyaniline;
- Carbon cloth