From spent Zn-MnO₂ primary batteries to rechargeable Zn-MnO₂ batteries: A novel directly recycling route with high battery performance

For the first time, spent Zn-MnO2 primary batteries are recycled to directly build rechargeable Zn-MnO2 batteries with a mixed solution of sulfuric acid and hydrogen peroxide as the leachate, which aimed to the efficient recovery of spent Zn-MnO2 primary batteries and the realization of high-powered rechargeable Zn-MnO2 batteries. After simple purification, the leached liquid is directly used as the working solution to prepare an electrolytic rechargeable Zn-MnO2 battery. The experimental results show that the performance of the recycling solution of the neutral Zn-MnO2 primary battery was better than that of the alkaline Zn-MnO2 primary battery, and both performed better than the solution prepared with chemically pure reagents. After optimizing the pH of the working solution and charging current, the obtained rechargeable Zn-MnO2 battery can provide an energy efficiency of 72.33 % +/- 0.55, a coulombic efficiency of 90.17 % +/- 0.71, and excellent cycle stability. These experimental results show that spent Zn-MnO2 primary batteries can be successfully recycled to prepare rechargeable Zn-MnO2 batteries, demonstrating very good application potential.