Recycling, recovery, and reuse of metal halides from waste multi-metal and halogen-containing perovskite solar cells

Abstract

Metal halide perovskite solar cells (PSCs) are moving toward commercialization but rely on toxic lead and resource-constrained halides, making recycling and circular use of these species imperative. Here, we develop and demonstrate a closed-loop hydrometallurgical route that separates and recovers Pb, Cs, I, and Br from degraded multi-metal, multi-halide PSCs (CsPbBrₓI3-x and (Cs1-nMAnFAm)Pb(BrxI1-x)3) into high-purity, device-grade precursors. Waste PSCs are delaminated in DMF, followed by H₂O₂-driven selective oxidation and sublimation of I2, aqueous partitioning into Pb-rich solids and Cs/Br-rich liquors, and dual Pb recovery paths via calcination to PbO or precipitation to PbI2. Cs is selectively extracted from the mixed halide liquor using t-BAMBP, stripped with NH4OH, and recovered as CsI using recycled I₂, while the Pb/Br raffinate is concentrated to PbBr2. The resulting PbO, PbI2, CsI, and PbBr2 reach metal purities above 98.7–99.8% and enable near-quantitative element recovery. Using recovered PbI2, we refabricate PSCs that preserve the target perovskite phase, exhibit only modest changes in microstructure and photophysics, and deliver average power conversion efficiencies around 20% with fill factor, open-circuit voltage, and short-circuit current density comparable to devices made from commercial PbI2. These results establish a practical, composition-tolerant recycling and reuse strategy that couples efficient metal halide recovery with high-performance device refabrication, providing a credible blueprint for circular manufacturing in perovskite photovoltaics.