Defect-Engineered La-Mn Co-Doped β-PbO2 Anodes for Energy-Efficient Zinc Electrowinning

The high energy consumption of lead anodes in zinc production is caused by the slow oxygen evolution reaction (OER). We made a La-Mn co-doped β-PbO2 anode using electrodeposition to solve this issue. The XRD and XPS results show that adding La shrinks the lattice and changes the electron structure. This helps Mn4+ change into active Mn3+ and creates more active oxygen on the surface, making the reaction easier. EIS tests show that the charge transfer resistance (Rct) decreased by 4.2 times, decreasing from 147.6 Ω to 34.72 Ω at 1.0 V. The Bode phase peak also moved to a lower frequency (from 122 Hz to 0.215 Hz), proving that the electrochemically active surface area (ECSA) increased significantly. At the industrial current of 50 mA cm−2, the anode shows a low overpotential of 840 mV and a Tafel slope of 265 mV dec−1. This improved performance saves 187.10 kWh of energy per ton of zinc. Therefore, the LaMn-β-PbO2 anode is a promising and energy-saving option for industrial zinc production.