Skip to content
BuildY

Aqueous-based recycling of perovskite photovoltaics

Idea Proposed

Image

a, Scheme of recycling process with a water-based solution. Three main additives (NaOAc, NaI and H3PO2) are added to address perovskite solubility, phase purity and solution stability issues in water solution. b, 1H-NMR of NaOAc with and without PbI2. The chemical shift suggests a strong interaction between acetate and lead ions to facilitate the PbI2 dissolution in water. c, Absorption curves of water-based solution (NaOAc: 500 mg ml−1, FAPbI3: 1 μmol) with various NaI concentrations. The inset shows solution with 35 mg ml−1 NaI fitted with [PbI2]0 and [PbI3]− peaks. d, DFT calculation of acetate ions coordination behaviour for facilitating lead iodide dissolution and phase change with the addition of iodide ions in water solution for perovskite recycling. Structures i, ii and iii denote PbI2L4, Pb2I4L6 and [Pb2I5L6]−, respectively, in which L is the acetate ions. a.u., arbitrary units.



This recycling method restores perovskite solar cells by dissolving degraded perovskite layers in an eco-friendly aqueous solution and recovering essential materials for reuse.

Process:

  1. Thermal Treatment & Delamination:

    • The perovskite solar module is heated to 150°C for 3 minutes, softening the encapsulant (ethylene vinyl acetate, EVA).
    • This allows easy separation of the glass cover and various layers.

  2. Aqueous-Based Perovskite Recycling:

    • The perovskite layer is dissolved in water containing sodium acetate (NaOAc), sodium iodide (NaI), and hypophosphorous acid (H3PO2).
    • Sodium acetate enhances solubility by forming lead acetate, making the lead iodide dissolve efficiently.
    • Sodium iodide ensures that the perovskite phase is preserved during precipitation.
    • Hypophosphorous acid stabilizes the solution by preventing oxidation of iodide ions.

  3. Precipitation and Recovery:

    • The dissolved perovskite solution is cooled gradually, allowing high-purity perovskite crystals to reform.
    • The recycled perovskite can then be used to create new high-efficiency solar cells, maintaining nearly identical performance to fresh materials.

  4. Holistic Recycling of Other Components:

    • Hole-transport material (spiro-OMeTAD) is extracted using ethyl acetate (EA) and ethanol, purified, and reused.
    • Gold electrodes are collected by centrifugation and reused without further processing.
    • ITO-coated glass substrates are cleaned and treated with ultraviolet–ozone to restore their optical and electrical properties.

How to Implement This Recycling Process

  1. Set Up Recycling Infrastructure

    • Establish a thermal treatment station to delaminate perovskite modules.
    • Create a water-based processing unit with controlled temperatures for dissolving and reforming perovskite crystals.

  2. Prepare the Aqueous Solution

    • Mix sodium acetate (500 mg/mL), sodium iodide (800 mg/mL), and hypophosphorous acid (40 μL/mL) in deionized water.
    • Heat the solution to 80°C before dissolving the perovskite layer.

  3. Recycle the Perovskite Layer

    • Immerse degraded perovskite films in the hot aqueous solution for 20 minutes.
    • Remove the substrate and cool the solution slowly to allow high-quality perovskite crystals to precipitate.
    • Separate and dry the crystals in a vacuum oven at 60°C before reusing them.

  4. Recover Other Components

    • Extract and purify spiro-OMeTAD using ethyl acetate and ethanol.
    • Collect gold electrodes through centrifugation.
    • Clean and treat ITO-coated glass with ultraviolet–ozone before reuse.

  5. Integrate Recycled Materials into New Solar Cells

    • Use the recovered materials to fabricate new perovskite solar modules, completing a circular economy for solar energy.

Sources & citation

Xiao, X., Xu, N., Tian, X. et al. Aqueous-based recycling of perovskite photovoltaics. Nature (2025). https://doi.org/10.1038/s41586-024-08408-7