A Green Lead Recycling Strategy from Used Lead Acid Batteries for Efficient Inverted Perovskite Solar Cells

Lead is widely used as a crucial elemental for lead acid batteries (LABs) and emerging halide perovskite solar cells (PSCs). However, the use of soluble lead will raise environmental concerns. For the purpose of Pb recycling, herein, we report a reactant-recycling strategy to extract Pb from used LABs and synthesize high-purity PbI₂. The recycled PbI₂ shows smaller grain size, higher crystallinity, and higher thermal stability compared to the commercial sources. Perovskite films deposited with the high-quality PbI₂ show larger grain size and fewer defects than the commercial ones. Consequently, the synthesized PbI₂ enables a power conversation efficiency of 20.45% for the inverted MAPbI₃ (MA= methylammonium) PSCs with excellent air stability. This work offers a novel strategy for lead recovery from LABs and a green path for the realization of high-performance PSCs with high defect tolerance.