Zn-anode stability in additive added perchlorate electrolyte for aqueous Zn-MnO2 battery

Extensive research has been conducted on aqueous Zn-MnO2 batteries in the most common ZnSO4 electrolyte. However, the present study focuses on Zn anode stability and subsequent pairing with the commonly utilized MnO2 cathode in a low-concentration aqueous Zn (ClO4)(2) electrolyte containing an organic additive, triethyl phosphate (TEP). The structural stability of Zn anodes in optimized additive-added and additive-free electrolytes is analyzed by assembling series of Zn parallel to Zn symmetry cells under various electrochemical conditions with varying depth of discharges between 20 and 60 %. As such, additive added electrolyte stabilizes the Zn anode over 250 h under high areal capacity/low areal current density of 38.3 mAh cm(-2)/11.3 mA cm(-2) with 60 % depth of discharge at long half-cycle time of 29.5 h. The Zn-MnO2 paired cells in the Zn (ClO4)(2) electrolyte with and without additives registered reversible capacities of 262 and 247 mAh g(-1), respectively, at 0.05 A g(-1). These electrochemical features are completely different from those of the common ZnSO4 electrolyte, whose electrochemical mechanism is still a subject of debate.