Studies on the Effect of Nano-Sized MgO in Magnesium-Ion Conducting Gel Polymer Electrolyte for Rechargeable Magnesium Batteries

Magnesium-ion conducting gel polymer electrolytes (GPEs) with different contents of nano-sized MgO have been prepared and investigated by various electrical and electrochemical techniques. The Mg2+ ion conduction in GPEs was confirmed from cyclic voltammetry and impedance analysis. It was found that doping appropriate nano-sized MgO in the GPE can induce significant improvements in both the electrochemical and the mechanical properties of GPEs. The composite GPE with 7% MgO shows a high ionic conductivity of 4.6 × 10−3 S/cm with electrochemical stability up to 4.7 V versus Mg2+/Mg at room temperature. Furthermore, it is free-standing and flexible with high tensile strength (9.7 ± 0.1 MPa) and elongation at break (91.7 ± 0.2%), further ensuring their potential applications as GPEs for rechargeable Mg batteries.