Performance studies on composite gel polymer electrolytes for rechargeable magnesium battery application

Effect of micron-sized MgO particles dispersion on poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF–HFP) based magnesium-ion (Mg 2+) conducting gel polymer electrolyte has been studied using various electrical and electrochemical techniques. The composite gel films are free-standing and flexible with enough mechanical strength. The optimized composition with 10 wt% MgO particles offers a maximum electrical conductivity of ∼6×10 −3 S cm −1 at room temperature (∼25°C). The Mg 2+ ion conduction in gel film is confirmed from cyclic voltammetry, impedance spectroscopy and transport number measurements. The applicability of the composite gel electrolyte to a rechargeable battery system has been examined by fabricating a prototype cell consisting of Mg (or Mg–MWCNT composite) and V 2O 5 as negative and positive electrodes, respectively. The rechargeability of the cell has been improved, when Mg metal was substituted by Mg–MWCNT composite as negative electrode. ► Studied the effect of micron-sized MgO dispersion on Mg 2+-conducting gel polymer electrolytes. ► Composite gel electrolyte films are fast ion conducting and mechanically stable. ► Dispersion of MgO in gel electrolyte results in enhancement in Mg 2+ ion transport number. ► Applicability of the gel electrolyte is examined in a proto-type rechargeable Mg-battery. ► Rechargeability of the Mg-cell is improved, when Mg metal is replaced by Mg–MWCNT composite anode.