Magnesium-sulfur (Mg-S) batteries offer excellent energy density, safety, and a
cost-effective energy storage system. Realizing Mg-S batteries requires bypassing
significant challenges like electrolyte compatibility with electrophilic sulfur and
Mg metal and polysulfide shuttling. The present work probes the role of 2-ethyl
hexylamine (EHA) in modifying the physiochemical properties of solid polymer
electrolytes (SPEs) based on polyvinyl alcohol (PVA), silicon dioxide (SiO2), and
magnesium triflate (MgTIF). The introduction of EHA increases the conductiv
ity to approximately 10−7 S/cm at room temperature, reduces the magnesium
stripping/plating overpotential, and improves the interfacial electrode/electrolyte
kinetics; further, the optimum concentration (y = 3000 μl) of PVST_yEHA shows a
high ionic transference number (tmg2+ = 0.88) (where PVST is an abbreviation for
compound composed of (PVA, SiO2, MgTIF)), there is minimal overpotential over
100 h. Based on optimum concentration (y = 3000 μl), the Mg-S battery exhibits a
high initial discharge-specific capacity in the first cycle up to 1837 mAhg−1, and
over six cycles, it maintained a reversible capacity of 376 mAhg−1. The present
article attempts to overcome some obstacles that prohibit the realization of Mg-S
batteries. |
