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 (Mg2+) 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 Mg2+ 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 V2O5 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 Mg2+-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 Mg2+ 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.