A general method for recycling and regenerating lead-containing perovskite devices

Abstract

A general method for recycling and regenerating lead-containing perovskite devices belongs to the field of optoelectronic materials and device recycling. The method includes the following steps: impregnating waste perovskite devices with a highly polar solvent to obtain a cathode, anode, substrate, and leachate; mixing the leachate containing perovskite and transport functional materials with a hot saturated halide aqueous solution for reaction, resulting in the precipitation of lead halide and transport functional materials in the upper layer, and a mixture of highly polar solvent and a small amount of water in the lower layer; deeply washing and separating the above-mentioned lead halide and functional material mixture with deionized water and chlorobenzene sequentially to obtain a pure lead halide and chlorobenzene solution containing functional materials; using the above-mentioned electrodes, substrate, and the above-mentioned lead halide and transport functional materials to fabricate perovskite devices, thus achieving device regeneration. This invention provides a simple and rapid recovery of each functional layer of the device, without secondary pollution, and the energy conversion efficiency of the regenerated device exceeds that of the original device, approaching 23%, with excellent stability.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic materials and devices, specifically involving the recycling and regeneration of key materials from discarded perovskite devices. Background Technology

[0002] With rapid global economic development and a continuously growing world population, global energy demand is rising steadily. However, increasingly depleted traditional fossil fuels are insufficient to meet human needs, which in turn severely hinders global economic development and the improvement of people's living standards. Finding green and renewable energy sources to replace traditional fossil fuels is a common challenge facing humanity. Solar energy is the most promising green and renewable energy source for the future. Solar cells, as one of the effective ways to utilize solar energy, have evolved from the traditional first-generation crystalline silicon cells to the third-generation thin-film cells.

[0003] Perovskite solar cells, as one of the most promising third-generation thin-film batteries, have many advantages over currently mass-produced crystalline silicon solar cells, such as lower production costs, better stability, simpler manufacturing processes, and the ability to create flexible and tandem cells. However, current perovskite solar cells generate a large number of aged or discarded cells after use. The perovskite material contains lead, a common toxic element, and its large-scale disposal would cause serious environmental pollution. The electrodes and perovskite materials in perovskite solar cells are expensive, and discarding them after a single use would result in a significant waste of production costs. Moreover, lead-containing perovskite materials are not only used in solar cell devices but also widely used in LED devices and photodetectors. Therefore, developing a low-cost, simple, and rapid method for the regeneration of lead-containing perovskite devices is of great significance. Summary of the Invention

[0004] To address the existing problems, the purpose of this invention is to provide a general method for recycling and regenerating lead-containing perovskite devices that is low-cost and can be implemented simply and quickly.

[0005] The inventors discovered that aged or discarded perovskite solar cells can be separated from their electrodes, substrates, and lead-containing solutions by immersion in a polar solvent. After deep cleaning, the electrodes and substrates are recovered. A hot saturated halide aqueous solution is added to the lead-containing solution, precipitating a mixture of lead halide and functional layer material. This precipitate is then washed sequentially with deionized water and chlorobenzene, yielding recovered lead halide and a chlorobenzene solution containing the functional layer material. Reintegrating the recovered electrodes, substrate, lead halide, and functional materials into a battery device results in an energy conversion efficiency exceeding that of a fresh device, approaching 23%, with good stability. This invention is simple, rapid, and low-cost, effectively achieving high-performance regeneration of battery devices and is suitable for large-scale recycling and regeneration of photovoltaic devices using perovskite as the key material.

[0006] This invention is achieved through the following technical means:

[0007] A general method for recycling and regenerating lead-containing perovskite devices is characterized by the following steps: (1) impregnating waste perovskite devices with a single or mixed strong polar solvent, filtering and centrifuging the devices to obtain a cathode, anode and substrate respectively, and obtaining a leachate containing perovskite and transport functional materials; (2) mixing the leachate obtained in step (1) with a hot saturated halide aqueous solution for reaction, the upper layer precipitates lead halide and transport functional materials, and the lower layer is a mixture of strong polar solvent and a small amount of water, and then separating the upper and lower layers; (3) deeply washing the mixture of lead halide and functional materials in step (2) with deionized water and chlorobenzene in sequence and centrifuging to obtain pure lead halide and chlorobenzene solution containing functional materials respectively; (4) using the electrode, substrate, lead halide and chlorobenzene solution of transport functional materials obtained in step (1), to prepare perovskite devices and realize device regeneration; (5) recovering the pure strong polar solvent by vacuum distillation of the mixed solution of strong polar solvent and water corresponding to the lower layer obtained in step (2).

[0008] Lead-containing perovskite devices are photovoltaic devices, LED devices, and photodetectors in which toxic lead is contained in the core perovskite functional layer.

[0009] The strongly polar solvent is any one of the following: aprotic polar solvent, amine solvent, and alcohol solvent.

[0010] The cathode is any one of the following electrodes: high-conductivity transition metal, fragmented graphite, high-transmittance conductive oxide, and ultrathin transition metal; the anode is any one of the following electrodes: ultrathin high-transmittance electrode.

[0011] The hot saturated halide aqueous solution has a temperature range of 80~100 °C; the halide is selected from KI, KBr, etc.

[0012] The aforementioned transport-functional material is an organic material with carrier transport capability.

[0013] The specific steps are as follows:

[0014] (1) Recovery of device cathode, anode and substrate

[0015] Waste lead-containing perovskite devices collected in the laboratory or pilot line are directly immersed in a beaker or corresponding container containing a highly polar solvent and stirred until all transparent conductive anodes, metal (graphite) cathodes and substrates are precipitated and the solution turns pale yellow. The precipitate is then filtered out to obtain the leachate. The precipitated electrodes and substrates are thoroughly cleaned, dried with dry and clean nitrogen or argon gas, and sealed for later use.

[0016] (2) Preparation of hot saturated halide aqueous solution

[0017] The halide is added to hot deionized water until a small amount of halide precipitates out, and then kept warm to obtain a hot saturated halide aqueous solution.

[0018] (3) Recycling of lead halides and transport functional materials

[0019] The leachate obtained in step (1) is thoroughly mixed with the hot saturated halide aqueous solution in step (2) until the layers are separated. The upper and lower layers are separated by separation, and the upper layer is filtered to obtain a pale yellow precipitate. The precipitate is washed with deionized water to remove other water-soluble impurities to obtain lead halide and transport function material. Then, the precipitate is washed with chlorobenzene to obtain pure lead halide and chlorobenzene solution containing transport function material.

[0020] (4) Preparation of lead-containing perovskite precursors

[0021] Step (3) The recovered pure lead halide and AX are mixed in a molar ratio and dissolved in a solvent to prepare a perovskite precursor solution of a certain concentration;

[0022] (5) Regeneration of lead-containing perovskite devices

[0023] First, a uniform and dense carrier transport layer is deposited on the recycled transparent conductive anode substrate. The perovskite precursor from step (4) is coated on it and annealed to form a film. The chlorobenzene solution containing the transport function material obtained in step (3) is coated on the perovskite film and annealed to form a film. Finally, a cathode recovered in step (1) is deposited as the counter electrode to complete the regeneration of the lead-containing perovskite device.

[0024] For AX, A is one or more mixed cations of different proportions from metal or organic cations, preferably with an ionic radius of approximately 215 pm, and X is one or more mixed anions of different proportions from halogen or organic anions, preferably with an ionic radius of approximately 225 pm. Annealing is performed in one or two steps at low temperature (≤150 °C) for several minutes. Especially when at least one of A or X in AX is an organic structure, the second annealing temperature is preferably 90-120 °C for 5-10 minutes, resulting in better crystallinity. When both A and X in AX are inorganic ions, the annealing temperature is 150 °C. This invention provides a simple and rapid recovery of the functional layers of the device, without secondary pollution. The energy conversion efficiency of the regenerated device exceeds that of the original device, approaching 23%, and exhibits excellent stability.

[0025] Compared with existing technologies, the advantages of this invention are:

[0026] 1) This invention not only achieves low-cost, simple and fast recovery of key materials in each layer of lead-containing perovskite devices, but also recovers the polar solvents used in the recovery process, making the recovery process green and environmentally friendly.

[0027] 2) This invention integrates regenerated devices by recycling key materials from each layer, and its energy conversion efficiency exceeds that of fresh devices, with excellent stability.

[0028] 3) This invention significantly reduces the cost of devices by performing high-performance regeneration of aged or discarded perovskite solar cells. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the recycling process of key materials from waste perovskite solar cells in Examples 1 & 2. The method is fast, simple, low-cost, and produces no pollution.

[0030] Figure 2 The image shows a comparison of the microstructures of fresh and recycled lead iodide in Example 1, with no significant differences.

[0031] Figure 3 The graph shows a comparison of the JV curves of fresh and regenerated battery devices using MAPbI3 (annealed at 100°C for 8 min) as the light-absorbing material in Example 1 under sunlight. The efficiency of the regenerated device exceeds that of the fresh device, reaching 22.78%.

[0032] Figure 4 This is a comparison of the transmittance of fresh and recycled ITO substrates under sunlight in Example 1, with no significant difference.

[0033] Figure 5For the aging test of the unencapsulated regenerated device (annealed at 100°C for 8 minutes) in Example 1, after being stored in an air environment under sunlight for 50 days (corresponding to May and June in Beijing, when the humidity is relatively high), it still has an initial efficiency value of 90%.

[0034] Figure 6 The purity and other impurity content of PbI2 recovered from different strongly polar solvents in Example 1 are shown.

[0035] Figure 7 The microstructure and surface roughness of MAPbI3 films prepared from PbI2 recovered from different strongly polar solvents in Example 1 are shown.

[0036] Figure 8 The XRD patterns of MAPbI3 films prepared with DMF as solvent and at different annealing temperatures in Example 1 using recycled PbI2 containing K ions are shown to explore the specific mechanism of K ions in the film formation process.

[0037] Figure 9 The images show the microstructure of MAPbI3 films prepared from recovered PbI2 containing K ions at different annealing temperatures using DMF as the solvent in Example 1. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and examples, but the present invention is not limited to the following embodiments.

[0039] Example 1

[0040] 1) Recovery of silver electrode and ITO substrate:

[0041] Two hundred collected waste lead-containing perovskite battery devices were immersed in a beaker containing a certain amount of DMF, BA, or DMSO. The mixture was magnetically stirred for 2 hours until the silver electrode and ITO substrate were completely precipitated, and the solution turned pale yellow. The pale yellow solution containing the ITO substrate and silver electrode precipitate was then filtered. The ITO substrate and silver electrode were collected and dried with clean nitrogen gas. The mixture was then irradiated under a UV-ozone lamp for a certain period of time. After the irradiation was completed and the mixture cooled to room temperature, it was removed and sealed in a dry packaging box.

[0042] 2) Preparation of hot saturated KI aqueous solution:

[0043] Dissolve a certain amount of white KI powder in deionized water at 80-100 ℃ until a small amount of white precipitate is formed, then keep warm.

[0044] 3) Recovery of lead iodide and hole transport materials:

[0045] The lead-containing leaching solution obtained in step (1) and the hot saturated KI aqueous solution in step (2) were stirred for a certain period of time and then allowed to stand until stratification occurred. The upper and lower layers were separated by liquid-liquid separation, and the upper layer was filtered to obtain the precipitated lead iodide and hole transport material. The precipitate was washed with deionized water to remove other water-soluble impurities to obtain lead iodide and hole transport material. The precipitate was then washed with chlorobenzene to obtain a pure lead iodide and chlorobenzene solution containing hole transport material.

[0046] 4) Preparation of MAPbI3 precursor solution:

[0047] The lead iodide (PbI2) recovered in step (3) was mixed with MAI at a molar ratio of 1.03:1 and dissolved in a mixed solvent of DMF / DMSO at a volume ratio of 9:1. The solution was stirred at room temperature for a certain period of time to obtain a clear and transparent solution.

[0048] 5) Regeneration of perovskite solar cells:

[0049] A 15 wt.% SnO2 colloidal dispersion was diluted to a low mass fraction and spin-coated onto a recovered ITO substrate at a rotation speed of 2500-3000 rpm for 30-40 s. After annealing at 80-120 ℃ for a period of time, a dense SnO2 film was formed. A certain amount of the precursor solution from step (4) was spin-coated onto the dense SnO2 film at a rotation speed of 2000-3000 rpm for 30-50 s. After annealing at different temperatures for a period of time (preferably annealing at 90-120 ℃ for 8 min, or further annealing at 100 ℃ for 8 min), a MAPbI3 film was formed. The chlorobenzene solution of the hole transport material recovered in step (3) was spin-coated onto the MAPbI3 film at a rotation speed of 2000-3000 rpm for 20-30 s without annealing. Finally, a layer of silver electrode recovered in step (1) was vapor-deposited to complete the regeneration of the battery device.

[0050] The regenerated perovskite solar cell generates a continuous and stable photovoltage and photocurrent under standard sunlight irradiation, achieving a power conversion efficiency of 22.78%, which surpasses the previous fresh cell device (20.76%), and exhibits good stability.

[0051] Example 2

[0052] 1) Recycling of carbon electrodes and CNT / glass substrates:

[0053] Two hundred collected waste carbon electrode lead-perovskite solar cell devices were immersed in a beaker containing a certain amount of DMF and DMSO mixed solvent. The mixture was magnetically stirred for 2 hours until the carbon electrodes and CNT / glass substrates were completely precipitated, resulting in a pale yellow solution. The pale yellow solution containing the CNT / glass substrate and carbon electrode precipitate was then filtered. The CNT / glass substrates were collected, dried with clean nitrogen, and irradiated under a UV-ozone lamp for a certain period. After irradiation and cooling to room temperature, the substrates were removed and sealed in a dry packaging box. A suitable amount of organic solvent was added to the collected carbon electrodes to prepare a new carbon slurry, which was then sealed and stored for later use.

[0054] 2) Preparation of hot saturated KBr aqueous solution:

[0055] Dissolve a certain amount of white KBr powder in deionized water at 80-100 ℃ until a small amount of white precipitate is formed, then keep warm.

[0056] 3) Recovery of lead bromide and hole transport materials:

[0057] The lead-containing leachate obtained in step (1) was stirred with the hot saturated KBr aqueous solution in step (2) for a certain period of time and then allowed to stand until stratification occurred. The upper and lower layers were separated by liquid-liquid separation, and the upper layer was filtered to obtain the precipitated lead bromide and hole transport material. The precipitate was washed with deionized water to remove other water-soluble impurities to obtain lead bromide and hole transport material, and washed with chlorobenzene to obtain a pure lead bromide and chlorobenzene solution containing hole transport material.

[0058] 4) Preparation of MAPbI3 precursor solution:

[0059] A certain amount of lead bromide (PbBr2) recovered in step (3) was mixed with PbI2 and CsI in a molar ratio of 0.5:0.5:1, dissolved in DMSO solvent, and stirred at room temperature for a certain time to obtain a clear and transparent solution.

[0060] 5) Regeneration of perovskite solar cells

[0061] A 15wt.% SnO2 colloidal dispersion was diluted to a low mass fraction and spin-coated onto a recycled CNT / glass substrate at a speed of 2500-3000 rpm for 30-40 s. After annealing at 80-120 ℃ for a period of time, a dense SnO2 film was formed. A certain amount of the precursor solution from step (4) was spin-coated onto the dense SnO2 film at a speed of 2000-3000 rpm for 30-50 s. After annealing at 150 ℃ for a period of time, a CsPbI2Br film was formed. The chlorobenzene solution of the hole transport material recovered in step (3) was spin-coated onto the CsPbI2Br film at a speed of 2000-3000 rpm for 20-30 s without annealing. Finally, a layer of carbon slurry recovered in step (1) was scraped onto the film and annealed at 80-100 ℃ for 30 min to complete the regeneration of the battery device.

Claims

1. A general method for recycling and regenerating a lead-containing perovskite device, characterized by, Includes the following steps: (1) Recovery of the device cathode, anode and substrate; Waste lead-containing perovskite devices collected in the laboratory or pilot line are directly immersed in a beaker or corresponding container containing a highly polar solvent and stirred until all transparent conductive anodes, cathodes and substrates are precipitated and the solution turns pale yellow. The precipitate is then filtered out to obtain the leachate. The precipitated electrodes and substrates are thoroughly cleaned, dried with dry and clean nitrogen or argon gas, and sealed for later use. (2) Preparation of hot saturated halide aqueous solutions; Add the halide to hot deionized water until a small amount of halide precipitates out, then keep warm to obtain a hot saturated halide aqueous solution. (3) Recycling of lead halides and transport functional materials; Mix the leachate obtained in step (1) thoroughly with the hot saturated halide aqueous solution in step (2) until stratification occurs; The upper and lower layers of solution were separated by liquid-liquid separation. The upper layer was filtered to obtain a pale yellow precipitate. The precipitate was washed with deionized water to remove other water-soluble impurities, and then lead halide and transport functional material were obtained. The precipitate was then washed with chlorobenzene to obtain pure lead halide and chlorobenzene solution containing transport functional material, respectively. (4) Preparation of lead-containing perovskite precursors; Step (3) The recovered pure lead halide and AX are mixed in a molar ratio and dissolved in a solvent to prepare a perovskite precursor solution of a certain concentration; (5) Regeneration of lead-containing perovskite devices; First, a uniform and dense carrier transport layer is deposited on the recycled transparent conductive anode substrate. The perovskite precursor from step (4) is coated on it and annealed to form a film. The chlorobenzene solution containing the transport function material obtained in step (3) is coated on the perovskite film and annealed to form a film. Finally, a cathode recovered in step (1) is deposited as the counter electrode to complete the regeneration of the lead-containing perovskite device. Specific steps (5): Dilute 15wt.% SnO2 colloidal dispersion to a low mass fraction, spin coat it onto the recovered substrate at a speed of 2500-3000 rpm for 30-40 s, and anneal at 80-120℃ for a period of time to form a dense SnO2 film; take a certain amount of the precursor solution from step (4) and spin coat it onto the dense SnO2 film at a speed of 2000-3000 rpm for 30-50 s, and anneal at 90-120℃ for 8 min to form a film; spin coat the chlorobenzene solution of the hole transport material recovered in step (3) onto the film at a speed of 2000-3000 rpm for 20-30 s without annealing, and finally vapor deposit a layer of the electrode recovered in step (1) to complete the regeneration of the battery device.

2. The method of claim 1, wherein, Lead-containing perovskite devices are photovoltaic devices, LED devices, and photodetectors in which toxic lead is contained in the core perovskite functional layer.

3. The method of claim 1, wherein, The strongly polar solvent is any one of the following: aprotic polar solvent, amine solvent, and alcohol solvent.

4. The method according to claim 1, characterized in that, The cathode is any one of the following electrodes: high-conductivity transition metal, fragmented graphite, high-transmittance conductive oxide, and ultrathin transition metal; the anode is any one of the following electrodes: ultrathin high-transmittance electrode.

5. The method according to claim 1, characterized in that, The hot saturated halide aqueous solution has a temperature range of 80~100 °C; the halide is selected from KI and KBr.

6. The method according to claim 1, characterized in that, Step (5) Annealing temperature 100℃.

7. The method according to claim 1, characterized in that, For AX, A is one or more mixed cations of different proportions from metal or organic cations, and X is one or more mixed anions of different proportions from halogen or organic anions.

8. The method according to any one of claims 1-7, characterized in that, The energy conversion efficiency of the regenerative device is 22.78%.

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