Studying the effect of adding thiourea to HFE on Mg-S battery behavior and its properties

Abstract

The prolonged longevity of magnesium-sulfur batteries (Mg-S) with high energy density is still impeded by the slow kinetics of sulfur reduction and evolution and the severe polysulfide (PS) shuttling. Herein, improve of the Mg-S battery was tried by using thiourea (TU) as an additive to the halogen free electrolyte (HFE) which based on dissolving Mg(NO3)2.6H2O to acetonitrile and ethylene glycol dimethyl ether (ACN: G4). The erosion of the magnesium layer and the inability of magnesium ions to reach the cathode in significant quantities during the charging and discharging process are two frequent battery problems. Consequently, thiourea was applied as a corrosion inhibitor, allowing magnesium ions to pass through while also creating a protective layer on the anode's surface. From the electrochemical tests, Mg||Mg symmetric cells it can be observed that the most plating|stripping ratio of TU in HFE is HFE-TU0.05 in 100 h. cycling. Mg|HFE-TU0.05|MoS2 cells were analyzed during the discharge/charge process. It was observed that HFE-TU0.05 improve the cycling capacitance and coulombic efficiency (CE%) . The post-mortem analysis applied for the analysis of cathodes in the discharge and charge cells.