Performance study of magnesium-polyaniline rechargeable battery in 1-ethyl-3-methylimidazolium ethyl sulfate electrolyte

A novel electrolyte system for the magnesium-polyaniline rechargeable battery containing 0.025 M magnesium sulfate (MgSO₄) in 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES) has been developed. The electrochemical properties of magnesium and polyaniline electrodes in the MgSO₄-EMIES solution are investigated, respectively. The results show that the corrosion potential of magnesium is -1.55 V (vs. SCE) in 0.025 M MgSO₄-EMIES and magnesium has high dissolution and deposition reversibility in the solution. Polyaniline shows good oxidation and reduction reversibility in 0.025 M MgSO₄-EMIES and the loose and porous structure of polyaniline is helpful to the doping and de-doping of anions as well as electron transfer. The study of the effect of current density on discharge capacity shows that the magnesium-polyaniline battery has higher discharge capacity at lower current density. At 667 mA g^-1, magnesium-polyaniline battery has an average discharge potential of 2.10 V and the first cycle discharge capacity could be 116 mAh g^-1. The magnesium-polyaniline battery has good cycle performance and the coulombic efficiency of the 60th cycle can be nearly 95%. The new cheap and simple magnesium-polyaniline battery is of great significance in the future rechargeable battery.