Borohydride-based electrolyte system for Magnesium-Persulfate (Mg||MgS2O8) rechargeable battery

Abstract Coin cells with magnesium persulfate/reduced graphene oxide cathode, magnesium anode, and varying concentrations of magnesium borohydride/1,2-dimethoxyethane electrolyte were fabricated and assembled. The most favorable concentration of electrolyte was found to be 0.01 M as it exhibited the least percentage of decrease in maximum current response (11%). Thus, the coin cell with 0.01 M of the electrolyte was chosen to undergo chronopotentiometry to determine its capacity. Its open circuit voltage was measured to be around 2.0 V. The generated galvanostatic charge–discharge graph from chronopotentiometry confirmed the capability of the best-fabricated magnesium persulfate-based battery system to hold a charge. It yielded a reversible capacity of around 0.021 mAh. In addition, no corrosion on the components of the coin cell was observed and further characterization of the electrodes showed no presence of any passivating layer, further supporting the compatibility of the components and therefore the feasibility of a rechargeable magnesium persulfate-based battery.