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.