Poster (EARTH)

[PE1-002] Recovery of PbI₂ from spent perovskite solar cells

○Hong Paul Wang¹, M.-X. Zhuang¹, J.-E. Chang¹, Y.-L. Wei², C.-J. Jou³ (1. National Cheng Kung University, 2. Tunghai University, 3. National Kaohsiung First University of Science and Technology)

Keywords:perovskite solar cells, recycling of PbI2, recycling of FTO conducting glass

The power conversion efficiency (PCE) for perovskite solar cells (PSCs) possessing advantages of high efficiency and low-cost have rapidly been increased from 3.8 to 22.1% in seven years. Perovskite exhibits outstanding light absorption, long life of excitation, tunable band gap energy and relative low cost has been considered to be the next generation solar cells. In general, the perovskite layer in a PSC is formed by the reaction of PbI₂ with CH₃NH₃I. PbI₂ may not be replaced by SnI₂ that is more toxic than PbI₂. Thus, recovery of PbI₂ from spent PSCs is becoming of great importance. Experimentally, PbI₂ can be extracted from spent PSCs by water. By XRD, the characteristic peak (2θ = 12.7^o) of PbI₂ in spent PSCs exists before water extraction and disappears after the treatment. With this approach, a conceptual process design for recovery of PbI₂, TiO₂, and FTO conducting glasses from spent PSCs was carried out. Clean FTO conducting glasses can be recovered by water extraction of the spent PSCs. After the solid and liquid filtration, two streams including the PbI₂ aqueous solution and TiO₂/carbon are separated. PbI₂ can be dried by hot gas generated from steam reforming of carbon in the TiO₂/carbon stream, and TiO₂ can be recovered as well. In this simple process, water is to be recycled, and a small portion of makeup water is needed.