A recycling method of waste photovoltaic modules

Abstract

The application provides a recycling method of waste photovoltaic modules, and belongs to the technical field of photovoltaic solid waste treatment. The method is aimed at the multilayer packaging structure of a fluorine-containing backboard photovoltaic module, a mass transfer inlet is established by slotting a predetermined safe area on the back of the module, the backboard is first peeled off, then the exposed packaging glue is subjected to interface reaction and layering, and local leaching is carried out after the silver grid line is exposed, and finally the separated glass is cleaned; the method sequentially connects the front separation of the fluorine-containing backboard, the interlayer interface dissociation, the directional transfer of silver and the purification of the glass surface, which is different from the whole crushing, whole heat treatment or whole soaking path, and can reduce the influence of multi-component mixing and interface residue on subsequent recycling, and is suitable for the classified recycling of glass, silicon matrix and silver in waste fluorine-containing backboard photovoltaic modules.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic solid waste treatment technology, and relates to a method for recycling waste photovoltaic modules. Background Technology

[0002] Photovoltaic modules are typically composed of multiple layers of materials, including glass, encapsulant, solar cells, solder ribbons, and backsheets. Even after long-term outdoor use and reaching the end of their service life, these layers maintain a strong bond. Due to differences in mechanical response, thermal stability, and chemical stability among glass, polymer encapsulation materials, silicon-based materials, and conductive metals, recycling waste photovoltaic modules is not simply a matter of dismantling a single material. It involves a comprehensive process encompassing multi-layer interface separation, control of different recycling flows, and adaptability for subsequent reuse. For photovoltaic modules with fluorinated backsheets, the backsheet material is tightly bonded to the encapsulant, solar cells, and conductive metal components, making them more prone to material entrainment, residue adhesion, and difficulties in subsequent sorting during recycling.

[0003] Among existing recycling methods, while overall mechanical crushing offers high processing efficiency, it typically mixes glass fragments, silicon wafers, electrode metals, and encapsulant residues, increasing the complexity of subsequent sorting processes. Furthermore, the dispersion of metal components in the mixed solids hinders targeted recycling. Overall heat treatment can weaken the bonding of the encapsulation structure to some extent, but for fluorinated backsheet modules, the heat treatment process may introduce fluorine decomposition products, fluorine residues, and carbonized deposits, affecting the cleanliness of the glass surface, silicon substrate, and metal recovery stream. Overall immersion treatment often causes significant bulk swelling, softening, or even gelation of the encapsulant, easily leading to residual encapsulant coverage on the glass surface, enhanced adhesion to the cell surface, and metal encapsulation. This hinders the orderly separation of the glass layer, encapsulant layer, and cell layer, and is also detrimental to the subsequent targeted recycling of silver.

[0004] Therefore, for waste photovoltaic modules with fluorine-containing backsheets, there is still a need for a recycling method that can take into account backsheet stripping, multi-layer interface separation, targeted metal recycling, and post-glass cleaning, in order to improve the problems of easy component mixing, difficult interface dissociation, and unclear silver recovery path in the existing treatment. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method for recycling waste photovoltaic modules. This method targets the multi-layer encapsulation structure of fluorinated backsheet photovoltaic modules. It establishes a mass transfer inlet by creating a groove in a predetermined safe area on the back of the module, first achieving backsheet peeling, then performing interfacial reaction delamination on the exposed encapsulating adhesive, followed by localized leaching after the silver grid lines are exposed, and finally cleaning the separated glass. This method sequentially connects the pre-separation of the fluorinated backsheet, interlayer interface dissociation, directional silver transfer, and glass surface purification, differing from overall crushing, overall heat treatment, or overall immersion paths. It reduces the impact of multi-component mixing and interfacial residues on subsequent recycling and is suitable for the classified recycling of glass, silicon substrate, and silver in waste fluorinated backsheet photovoltaic modules.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a method for recycling waste photovoltaic modules, the recycling method comprising:

[0008] S1: Using a multi-blade linkage rolling cutting device or a row-blade grooving machine, grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module. The cutting depth is controlled by a mechanical limit wheel, so that the cutting blade penetrates the backsheet and enters the encapsulation adhesive layer, but is blocked by the limit wheel and does not touch the cells, solder strips, and glass, thus obtaining the first pre-treated waste module.

[0009] S2: Dimethyl carbonate, isoparaffin Isopar L, miscibility aid and sorbitan monooleate are mixed and allowed to stand in a sealed container to obtain a wetting solution. The wetting solution is scraped onto the groove and inside the groove of the first pre-treated waste component. It is then kept warm under explosion-proof ventilation. Subsequently, a continuous peeling load is applied to peel off the back sheet in whole pieces or large pieces to obtain the second pre-treated waste component.

[0010] S3: A composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol. A catalyst is added to obtain a reaction solution. The reaction solution is coated on the surface of the encapsulant exposed in the second pre-treatment waste component and is kept at a constant temperature. After the treatment, a peel load is applied while the encapsulant film is still in a peelable state to separate the glass layer, encapsulant layer, and cell layer. After separation, the glass layer, encapsulant film, and cell layer are kept apart and cooled to reduce the re-adhesion of the encapsulant film to the glass layer or cell layer during the cooling process, resulting in a cell with an exposed glass layer, encapsulant film, and silver grid lines.

[0011] S4: Add ferric sulfate and thiourea to deionized water, add sulfuric acid to adjust the pH to obtain silver leaching solution, spray the silver leaching solution locally onto the exposed silver grid line of the battery cell in the form of atomized spray, so that the silver leaching solution mainly contacts the silver grid line area, and after leaching, remove the silicon substrate to obtain silver-rich leaching solution for subsequent silver recovery.

[0012] S5: Dissolve sodium carbonate, sodium citrate and fatty alcohol polyoxyethylene ether in water and adjust the pH to prepare a cleaning solution. Place the glass layer in the cleaning solution, clean it with ultrasound, remove it, rinse it with deionized water and dry it to obtain recycled glass.

[0013] As a preferred technical solution of the present invention, in step S1, the width of the slot is 0.2-1.0 mm, for example, it can be 0.2 mm, 0.28 mm, 0.36 mm, 0.44 mm, 0.52 mm, 0.60 mm, 0.68 mm, 0.76 mm, 0.84 mm, 0.92 mm or 1.0 mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] In some optional embodiments, the slot spacing is 10-30mm, for example, it can be 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm or 30mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0015] As a preferred embodiment of the present invention, in step S2, the mass ratio of dimethyl carbonate, isoparaffin IsoparL, miscibility aid, and sorbitan monooleate is (50-70):(15-35):(5-15):(0.5-3), for example, it can be (50, 52, 54, 56, 58, 60, 62, 64, 66, 68 or 70):(15, 17, 19, 21, 23, 25, 27, 29, 31, 33 or 35):(5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15):(0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75 or 3), but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0016] The miscibility aid is propylene glycol methyl ether or propylene glycol methyl ether acetate.

[0017] In some optional embodiments, the settling time is 20-24 hours, for example, it can be 20 hours, 20.4 hours, 20.8 hours, 21.2 hours, 21.6 hours, 22 hours, 22.4 hours, 22.8 hours, 23.2 hours, 23.6 hours or 24 hours, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0018] In some optional embodiments, the amount of wetting liquid applied is 150-300 g / m³. 2 For example, it could be 150g / m2 165g / m 2 180g / m 2 195g / m 2 210g / m 2 225g / m 2 240g / m 2 255g / m 2 270g / m 2 285g / m 2 Or 300g / m 2 However, this does not apply to all values ​​listed; other unlisted values ​​within the same range also apply.

[0019] In some optional embodiments, the temperature of the heat preservation treatment is 55-70°C, for example, it can be 55°C, 56.5°C, 58°C, 59.5°C, 61°C, 62.5°C, 64°C, 65.5°C, 67°C, 68.5°C or 70°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0020] In some optional embodiments, the heat preservation time is 20-50 min, for example, 20 min, 23 min, 26 min, 29 min, 32 min, 35 min, 38 min, 41 min, 44 min, 47 min or 50 min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0021] In some alternative embodiments, the load for continuous peeling is 0.5-2.0 N / mm, for example, it can be 0.5 N / mm, 0.65 N / mm, 0.8 N / mm, 0.95 N / mm, 1.1 N / mm, 1.25 N / mm, 1.4 N / mm, 1.55 N / mm, 1.7 N / mm, 1.85 N / mm or 2.0 N / mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0022] As a preferred technical solution of the present invention, in step S3, the mass ratio of propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in the composite solvent is (50-70):(20-30):(5-15), for example, it can be (50, 52, 54, 56, 58, 60, 62, 64, 66, 68 or 70):(20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30):(5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0023] In some optional embodiments, the mass ratio of the catalyst to the composite solvent is (0.1-1):100, for example, it can be 0.1:100, 0.19:100, 0.28:100, 0.37:100, 0.46:100, 0.55:100, 0.64:100, 0.73:100, 0.82:100, 0.91:100 or 1:100, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0024] The catalyst is any one of stannous octoate, zinc acetylacetonate, or zinc isooctanoate.

[0025] In some optional embodiments, the coating amount of the reaction solution is 80-150 g / m². 2 For example, it could be 80g / m 2 87g / m 2 94g / m 2 101g / m 2 108g / m 2 115g / m 2 122g / m 2 129g / m 2 136g / m 2 143g / m 2 Or 150g / m 2 However, this does not apply to all values ​​listed; other unlisted values ​​within the same range also apply.

[0026] In some optional embodiments, the temperature of the isothermal treatment is 90-115°C, for example, 90°C, 92.5°C, 95°C, 97.5°C, 100°C, 102.5°C, 105°C, 107.5°C, 110°C, 112.5°C or 115°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0027] In some optional embodiments, the isothermal treatment time is 1-3 hours, for example, it can be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0028] In some alternative embodiments, the peeling load is 0.1-1.0 N / mm, for example, it can be 0.1 N / mm, 0.19 N / mm, 0.28 N / mm, 0.37 N / mm, 0.46 N / mm, 0.55 N / mm, 0.64 N / mm, 0.73 N / mm, 0.82 N / mm, 0.91 N / mm or 1.0 N / mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0029] As a preferred technical solution of the present invention, in step S4, the concentration of iron ions derived from the ferric sulfate is 0.05-0.15M, for example, it can be 0.05M, 0.06M, 0.07M, 0.08M, 0.09M, 0.10M, 0.11M, 0.12M, 0.13M, 0.14M or 0.15M, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] In some alternative embodiments, the concentration of thiourea is 0.2-0.5M, for example, 0.2M, 0.23M, 0.26M, 0.29M, 0.32M, 0.35M, 0.38M, 0.41M, 0.44M, 0.47M or 0.5M, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0031] In some alternative embodiments, the addition of sulfuric acid to adjust the pH to 1.2-2 may be, for example, 1.2, 1.28, 1.36, 1.44, 1.52, 1.6, 1.68, 1.76, 1.84, 1.92 or 2, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0032] In some optional embodiments, the cumulative spray volume of the silver leaching solution to the mass ratio of the exposed silver grid cells is (5-15) mL:1g, for example, it can be 5mL:1g, 6mL:1g, 7mL:1g, 8mL:1g, 9mL:1g, 10mL:1g, 11mL:1g, 12mL:1g, 13mL:1g, 14mL:1g or 15mL:1g, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0033] In some alternative embodiments, the leaching temperature is 25-45°C, for example, it can be 25°C, 27°C, 29°C, 31°C, 33°C, 35°C, 37°C, 39°C, 41°C, 43°C or 45°C, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0034] In some alternative embodiments, the leaching time is 40-80 min, for example, it can be 40 min, 44 min, 48 min, 52 min, 56 min, 60 min, 64 min, 68 min, 72 min, 76 min or 80 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0035] As a preferred technical solution of the present invention, in step S5, the mass ratio of sodium carbonate, sodium citrate and fatty alcohol polyoxyethylene ether is (2-5):(1-3):(0.2-1.0), for example, it can be (2, 2.3, 2.6, 2.9, 3.2, 3.5, 3.8, 4.1, 4.4, 4.7 or 5):(1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8 or 3):(0.2, 0.28, 0.36, 0.44, 0.52, 0.6, 0.68, 0.76, 0.84, 0.92 or 1.0), but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0036] In some optional embodiments, the total mass fraction of the cleaning fluid is 2-8%, for example, it can be 2%, 2.6%, 3.2%, 3.8%, 4.4%, 5%, 5.6%, 6.2%, 6.8%, 7.4% or 8%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0037] In some alternative embodiments, the pH of the cleaning solution is 9-11, for example, it can be 9, 9.2, 9.4, 9.6, 9.8, 10, 10.2, 10.4, 10.6, 10.8 or 11, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0038] When the pH of the cleaning solution is lower than the target range, adjust it with a sodium hydroxide solution of 0.05-0.1M; when the pH of the cleaning solution is higher than the target range, adjust it with a citric acid solution of 0.1-0.5M.

[0039] In some optional embodiments, the mass-to-volume ratio of the glass layer to the cleaning fluid is 1 kg:(5-15) L, for example, it can be 1 kg:5 L, 1 kg:6 L, 1 kg:7 L, 1 kg:8 L, 1 kg:9 L, 1 kg:10 L, 1 kg:11 L, 1 kg:12 L, 1 kg:13 L, 1 kg:14 L or 1 kg:15 L, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0040] In some optional embodiments, the temperature of the ultrasonic cleaning is 50-70°C, for example, it can be 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0041] In some alternative embodiments, the frequency of the ultrasound is 30-40 kHz, for example, it may be 30 kHz, 31 kHz, 32 kHz, 33 kHz, 34 kHz, 35 kHz, 36 kHz, 37 kHz, 38 kHz, 39 kHz or 40 kHz, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0042] In some optional embodiments, the ultrasonic cleaning time is 10-30 min, for example, it can be 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min or 30 min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0043] The recycling method described in this application focuses on the multi-layer encapsulation structure of waste fluorine-containing backsheet photovoltaic modules. Its mechanism involves first shifting the action site from within the overall material to near a predetermined interface, then processing the components in the sequence of backsheet separation, interlayer dissociation, silver directional transfer, and glass surface cleaning. This allows different components to complete separation and transfer in relatively independent stages. This process does not uniformly destroy the entire module; rather, it reduces the possibility of simultaneous mixing of multiple components through preferential interface action and step-by-step coordination.

[0044] Grooving is performed on the edge encapsulation area, between adjacent cells, and the safety area outside the busbar on the back of the module. This allows the cutting edge to penetrate the backsheet and enter the encapsulating adhesive layer, but without touching the cells, solder ribbons, or glass. This grooving method creates a material transfer entrance extending from the backsheet to the encapsulating adhesive layer, allowing subsequent liquids to enter through the groove and spread along the local interface. Furthermore, the grooving itself establishes an initial stress relief point between the backsheet and the underlying structure, providing a clear starting boundary for subsequent backsheet peeling. Unlike overall shredding, this method concentrates the subsequent action area near the backsheet interface, which helps maintain the integrity of the glass layer and cell layer.

[0045] After the wetting solution is applied to the tank opening and inside the tank, dimethyl carbonate, isoparaffin Isopar L, miscibility aid, and sorbitan monooleate form a liquid-phase system with a certain interfacial spreading ability. Dimethyl carbonate and isoparaffin Isopar L have significant polarity differences, requiring the miscibility aid to diffuse sufficiently to form a stable transition layer between the two phases. Sorbitan monooleate, as a surfactant, also needs time to complete its adsorption and distribution at the interface. Therefore, allowing the wetting solution to stand in a sealed container for 20-24 hours helps the system achieve a uniform and stable dispersion, thus improving the spreading consistency during subsequent application. Dimethyl carbonate and the miscibility aid help regulate the system's polarity and flow state, isoparaffin Isopar L helps wet the backing plate and adjacent hydrophobic interfaces, and sorbitan monooleate helps reduce interfacial tension and improve the liquid's spreading behavior in narrow tanks and interfacial regions. This wetting process gradually loosens the adhesion between the backsheet and the encapsulating adhesive in the adjacent area. Under the combined effects of insulation and additional peel load, the backsheet is more easily detached in whole sheets or large chunks. The backsheet is peeled off before subsequent interfacial chemical treatment, separating the fluorine source from the main recovery path earlier, thereby reducing its interference with subsequent stratification and recovery streams.

[0046] After the backsheet is removed, the reaction solution acts directly on the exposed encapsulant surface. The reaction solution consists of a composite solvent and a catalyst. The composite solvent, composed of propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol, can solvate, wet, and locally plasticize the surface and adjacent areas of the encapsulant, loosening the originally tight interface. The catalyst is any one of stannous octoate, zinc acetylacetonate, or zinc isooctanoate. Under the wetting, solvation, and local plasticizing effects of the composite solvent, it mainly promotes limited alcoholysis, transesterification, or coordination of vinyl acetate units or interfacial polar groups on the surface and adjacent areas of the encapsulant interface, thereby weakening the interfacial bonding between the encapsulant and the glass layer and the battery cell layer.

[0047] The term "limited extent" does not mean that the reaction occurs exclusively at the interfacial monolayer. Rather, it means that under the combined effects of limited coating amount of reaction solution, controlled swelling capacity of the composite solvent on the cross-linked EVA bulk phase, limited isothermal treatment time, and timely application of peel load after treatment, the reaction solution preferentially acts on the surface layer of the encapsulant and the adjacent region of the interlayer interface, without causing bulk degradation or unrestrained gelation of the encapsulant as a whole. The above process mainly belongs to the debonding process in the adjacent region of the interface under mass transfer control and time control, rather than uniform chemical degradation of the entire encapsulant.

[0048] The aforementioned physical and chemical effects do not occur in isolation: the composite solvent increases the accessibility of the interfacial region, while the catalyst further weakens the interfacial bonding in this region. Subsequently, the weakened interface is delaminated by a peel load, causing the bonding between the glass layer, encapsulant film, and cell layer to gradually transform from a relatively stable state to a more easily peelable state. Under these conditions, the delamination process tends to develop along the region adjacent to the interface, rather than causing disordered destruction within the glass and cell body, nor does it transform the encapsulant into a gel-like residue. The separation of the encapsulant from the structure in the form of a film also provides conditions for the subsequent exposure of the silver grid lines.

[0049] It should be noted that the isothermal treatment in S3 does not cause the encapsulant to melt entirely or flow unrestrained. Instead, it uses a controlled amount of reaction solution to keep the surface and interface areas of the encapsulant in a peelable state. After the isothermal treatment, a peel load is applied promptly, and the separated glass layer, encapsulant film, and cell layer are kept physically separated. This reduces the risk of re-adhesion of the encapsulant film to the glass or cell layer during cooling. Thus, the thermal softening, interfacial chemical weakening, and mechanical delamination effects in S3 work together to make the encapsulant more likely to be removed as a film rather than remaining on the glass or cell surface as a viscous residue.

[0050] The exposed silver grid lines of the solar cells were locally leached using atomized spraying. In the silver leaching solution, ferric sulfate provided oxidizing iron ions, which promoted the conversion of metallic silver to the ionic state; thiourea formed a complex with the generated silver ions, reducing the free state of silver ions in the liquid phase, thereby promoting the transfer of silver from the solid phase to the liquid phase. Acidic conditions were beneficial for maintaining the stability of the oxidation-complexation process in the system. Compared with overall immersion, local spraying via atomization preferentially distributed the leaching solution in the area where the silver grid lines were exposed, helping to ensure that the silver leaching process focused on the target metal area and reducing ineffective contact of the liquid with other areas. This step was arranged after stratification, allowing the silver to enter the silver-rich leaching solution before crushing or mixing, thus maintaining a clearer metal recovery path.

[0051] The separated glass layer is then cleaned. Sodium carbonate in the cleaning solution provides an alkaline environment to loosen residual organic deposits; sodium citrate complexes residual metal ions or inorganic impurities on the surface; and fatty alcohol polyoxyethylene ether helps improve the wetting and emulsifying dispersion behavior of the glass surface. Combined with ultrasonic treatment, residual encapsulant debris, attached impurities, and some inorganic residues on the glass surface are more easily desorbed. Thus, the glass layer undergoes further surface purification based on the previous separation process.

[0052] The steps in this application are sequentially coordinated: grooving provides conditions for liquid introduction and localized stress release; the wetting liquid facilitates the initial peeling of the backsheet; the reaction liquid further dissociates the exposed interface after the backsheet peeling; silver leaching is based on the exposure of the silver grid lines; and glass cleaning corresponds to the surface purification requirements after delamination. This process path links mechanical action, interface wetting, limited chemical dissociation, localized oxidation complexation, and post-cleaning treatment, forming a step-by-step recycling mechanism for multi-layer encapsulated waste photovoltaic modules.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] Using a step-by-step process of first grooving and then peeling to process the fluorinated backsheet facilitates the separation of the backsheet from the main structure.

[0055] By applying a reaction solution to the exposed encapsulant surface and performing a constant-temperature treatment, the delamination of the glass layer, encapsulant film, and battery cell layer can be promoted, facilitating subsequent separate recycling.

[0056] Localized spray leaching after the silver grid lines are exposed helps to create a directional recycling path towards the silver grid line area.

[0057] After the glass layers are separated, they are cleaned to further adapt them to subsequent use requirements;

[0058] The entire method is implemented in the order of backsheet stripping, structural delamination, metal leaching, and glass purification. The recycling path is relatively clear and it is suitable for the step-by-step recycling of waste fluorine-containing backsheet photovoltaic modules. Detailed Implementation

[0059] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The embodiments described herein are specific implementations of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limiting the implementation of the present invention or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that employ any obvious substitutions and modifications made to the embodiments described herein.

[0060] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone further purification or processing.

[0061] Example 1

[0062] This embodiment provides a method for recycling waste photovoltaic modules, which specifically includes the following steps:

[0063] S1: Grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module. The cutting depth is controlled by mechanical limit wheels so that the cutting edge penetrates the backsheet and enters the encapsulation adhesive layer, but is blocked by the limit wheels and does not touch the cells, solder strips, and glass. The groove width is 1.0mm and the groove spacing is 30mm, resulting in the first pre-treated waste module.

[0064] S2: Dimethyl carbonate, isoparaffin Isopar L, propylene glycol methyl ether acetate (a miscibility aid), and sorbitan monooleate are mixed in a mass ratio of 70:15:15:3 and allowed to stand in a sealed container for 24 hours to obtain a wetting solution. The wetting solution is then applied to the opening and inside of the tank of the first pre-treated waste component, with an application rate of 300 g / m². 2 Under explosion-proof ventilation, the back panel is placed at 70℃ for 50 minutes for heat preservation, and then a continuous peeling load of 2.0 N / mm is applied to peel off the back panel in whole pieces or large pieces to obtain the second pre-treated waste component.

[0065] S3: A composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in a mass ratio of 60:28:12. Zinc isooctanoate is added as a catalyst to obtain a reaction solution, wherein the mass ratio of the catalyst to the composite solvent is 1:100. The reaction solution is then coated onto the exposed encapsulant surface of the second pretreated waste components, with a coating amount of 150 g / m². 2 The glass layer, encapsulant layer and cell layer were placed at 105℃ for 3 hours. After the treatment, a peel load of 1.0 N / mm was applied to separate the glass layer, encapsulant layer and cell layer. After separation, the glass layer, encapsulant film and cell layer were kept apart and cooled to obtain a cell with the glass layer, encapsulant film and silver grid lines exposed.

[0066] S4: Add ferric sulfate and thiourea to deionized water, wherein the concentration of ferric ions from ferric sulfate is 0.15M and the concentration of thiourea is 0.5M. Add sulfuric acid to adjust the pH to 2 to obtain a silver leaching solution. Spray the silver leaching solution locally onto the exposed silver grid lines of the solar cell in a mist spraying manner, so that the silver leaching solution mainly contacts the silver grid line area. The cumulative spray volume of the silver leaching solution to the mass ratio of the exposed silver grid line solar cell is 15mL:1g. The leaching temperature is 45℃ and the leaching time is 80min. After leaching, remove the silicon substrate to obtain a silver-rich leaching solution for subsequent silver recovery.

[0067] S5: Dissolve sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in water at a mass ratio of 4.5:2.5:0.5, and adjust the pH to prepare a cleaning solution with a total mass fraction of 8% and a pH of 9.5. Place the glass layer in the cleaning solution, wherein the mass-volume ratio of the glass layer to the cleaning solution is 1 kg:15 L. Clean the glass layer with ultrasonic waves at 40 kHz at 65 °C for 30 min. After cleaning, rinse with deionized water and dry to obtain recycled glass.

[0068] Example 2

[0069] This embodiment provides a method for recycling waste photovoltaic modules, which specifically includes the following steps:

[0070] S1: Grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module. The cutting depth is controlled by mechanical limit wheels, so that the cutting edge penetrates the backsheet and enters the encapsulation adhesive layer, but is blocked by the limit wheels and does not touch the cells, solder strips, and glass. The groove width is 0.2mm and the groove spacing is 10mm, thus obtaining the first pre-treated waste module.

[0071] S2: Dimethyl carbonate, isoparaffin Isopar L, propylene glycol methyl ether acetate (a miscibility aid), and sorbitan monooleate are mixed in a mass ratio of 50:35:5:0.5 and allowed to stand in a sealed container for 20 hours to obtain a wetting solution. The wetting solution is then applied to the opening and inside of the tank of the first pre-treated waste component, with an application rate of 150 g / m². 2 Under explosion-proof ventilation, the back panel is kept at 55℃ for 20 minutes, and then a continuous peeling load of 0.5N / mm is applied to peel it off in whole pieces or large blocks to obtain the second pre-treated waste component.

[0072] S3: A composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in a mass ratio of 50:30:5. Stannous octoate is added as a catalyst to obtain a reaction solution, wherein the mass ratio of the catalyst to the composite solvent is 0.1:100. The reaction solution is then coated onto the exposed encapsulant surface of the second pretreated waste components, with a coating amount of 80 g / m². 2 The glass layer, encapsulant layer and cell layer were placed at 90℃ for 1 hour. After the treatment, a peel load of 0.1 N / mm was applied to separate the glass layer, encapsulant layer and cell layer. After separation, the glass layer, encapsulant film and cell layer were kept apart and cooled to obtain a cell with the glass layer, encapsulant film and silver grid lines exposed.

[0073] S4: Add ferric sulfate and thiourea to deionized water, wherein the concentration of ferric ions from ferric sulfate is 0.05M and the concentration of thiourea is 0.2M. Add sulfuric acid to adjust the pH to 1.2 to obtain a silver leaching solution. Spray the silver leaching solution locally onto the exposed silver grid lines of the solar cell in a mist spraying manner, so that the silver leaching solution mainly contacts the silver grid line area. The cumulative spray volume of the silver leaching solution to the mass ratio of the exposed silver grid line solar cell is 5mL:1g. The leaching temperature is 25℃ and the leaching time is 40min. After leaching, remove the silicon substrate to obtain a silver-rich leaching solution for subsequent silver recovery.

[0074] S5: Dissolve sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in water at a mass ratio of 5:3:1.0, and adjust the pH to prepare a cleaning solution with a total mass fraction of 2% and a pH of 9. Place the glass layer in the cleaning solution, wherein the mass-volume ratio of the glass layer to the cleaning solution is 1 kg: 5 L. Clean the glass layer with ultrasonic waves at 30 kHz at 50 °C for 10 min. After cleaning, rinse with deionized water and dry to obtain recycled glass.

[0075] Example 3

[0076] This embodiment provides a method for recycling waste photovoltaic modules, which specifically includes the following steps:

[0077] S1: Grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module. The cutting depth is controlled by mechanical limit wheels so that the cutting edge penetrates the backsheet and enters the encapsulation adhesive layer, but is blocked by the limit wheels and does not touch the cells, solder strips, and glass. The groove width is 0.5mm and the groove spacing is 15mm, resulting in the first pre-treated waste module.

[0078] S2: Dimethyl carbonate, isoparaffin Isopar L, propylene glycol methyl ether (a miscibility aid), and sorbitan monooleate are mixed in a mass ratio of 65:20:12:1 and allowed to stand in a sealed container for 23 hours to obtain a wetting solution. The wetting solution is then applied to the opening and inside of the tank of the first pre-treated waste component, with an application rate of 200 g / m². 2 Under explosion-proof ventilation, the back panel is kept at 60℃ for 30 minutes, and then a continuous peeling load of 1.0 N / mm is applied to peel it off in whole pieces or large blocks to obtain the second pre-treated waste component.

[0079] S3: A composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in a mass ratio of 70:20:15. Zinc acetylacetone catalyst is added to obtain a reaction solution, wherein the mass ratio of catalyst to composite solvent is 0.5:100. The reaction solution is coated onto the exposed encapsulant surface of the second pretreated waste components, with a coating amount of 100 g / m². 2The glass layer, encapsulant layer and cell layer were placed at 115℃ for 2 hours. After the treatment, a peel load of 0.5 N / mm was applied to separate the glass layer, encapsulant layer and cell layer. After separation, the glass layer, encapsulant film and cell layer were kept apart and cooled to obtain a cell with the glass layer, encapsulant film and silver grid lines exposed.

[0080] S4: Add ferric sulfate and thiourea to deionized water, wherein the concentration of ferric ions from ferric sulfate is 0.08M and the concentration of thiourea is 0.3M. Add sulfuric acid to adjust the pH to 1.5 to obtain a silver leaching solution. Spray the silver leaching solution locally onto the exposed silver grid lines of the solar cell in a mist spraying manner, so that the silver leaching solution mainly contacts the silver grid line area. The cumulative spray volume of the silver leaching solution to the mass ratio of the exposed silver grid line solar cell is 8mL:1g. The leaching temperature is 30℃ and the leaching time is 50min. After leaching, remove the silicon substrate to obtain a silver-rich leaching solution for subsequent silver recovery.

[0081] S5: Dissolve sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in water at a mass ratio of 2:1:0.2, and adjust the pH to prepare a cleaning solution with a total mass fraction of 4% and a pH of 11. Place the glass layer in the cleaning solution, wherein the mass-volume ratio of the glass layer to the cleaning solution is 1 kg: 8 L. Clean the glass layer with ultrasonic waves at 38 kHz at 70 °C for 15 min. After cleaning, rinse with deionized water and dry to obtain recycled glass.

[0082] Example 4

[0083] This embodiment provides a method for recycling waste photovoltaic modules, which specifically includes the following steps:

[0084] S1: Using a multi-blade linkage rolling cutting device or a grooving machine, grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module. The cutting depth is controlled by mechanical limit wheels, so that the cutting blade penetrates the backsheet and enters the encapsulation adhesive layer, but is blocked by the limit wheels and does not touch the cells, solder strips, and glass. The groove width is 0.8mm and the groove spacing is 25mm, resulting in the first pre-treated waste module.

[0085] S2: Dimethyl carbonate, isoparaffin Isopar L, propylene glycol methyl ether (a miscibility aid), and sorbitan monooleate are mixed in a mass ratio of 60:25:10:2 and allowed to stand in a sealed container for 22 hours to obtain a wetting solution. The wetting solution is then applied to the opening and inside of the tank of the first pre-treated waste component, with an application rate of 250 g / m². 2 Under explosion-proof ventilation, the back panel is placed at 65℃ for 40 minutes for heat preservation, and then a continuous peeling load of 1.5N / mm is applied to peel off the back panel in whole pieces or large pieces to obtain the second pre-treated waste component.

[0086] S3: A composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in a mass ratio of 65:25:10. Stannous octoate is added as a catalyst to obtain a reaction solution, wherein the mass ratio of catalyst to composite solvent is 0.8:100. The reaction solution is then coated onto the exposed encapsulant surface of the second pretreated waste components, with a coating amount of 130 g / m². 2 The glass layer, encapsulant layer and cell layer were placed at 100℃ for 2.5 hours. After the treatment, a peel load of 0.8 N / mm was applied to separate the glass layer, encapsulant layer and cell layer. After separation, the glass layer, encapsulant film and cell layer were kept apart and cooled to obtain a cell with the glass layer, encapsulant film and silver grid lines exposed.

[0087] S4: Add ferric sulfate and thiourea to deionized water, wherein the concentration of ferric ions from ferric sulfate is 0.12M and the concentration of thiourea is 0.4M. Add sulfuric acid to adjust the pH to 1.8 to obtain a silver leaching solution. Spray the silver leaching solution locally onto the exposed silver grid lines of the solar cell in a mist spraying manner, so that the silver leaching solution mainly contacts the silver grid line area. The cumulative spray volume of the silver leaching solution to the mass ratio of the exposed silver grid line solar cell is 12mL:1g. The leaching temperature is 40℃ and the leaching time is 70min. After leaching, remove the silicon substrate to obtain a silver-rich leaching solution for subsequent silver recovery.

[0088] S5: Dissolve sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in water at a mass ratio of 4:2:0.8, and adjust the pH to prepare a cleaning solution with a total mass fraction of 6% and a pH of 10. Place the glass layer in the cleaning solution, wherein the mass-volume ratio of the glass layer to the cleaning solution is 1 kg:12 L. Clean the glass layer with ultrasonic waves at 35 kHz at 60 °C for 25 min. After cleaning, rinse with deionized water and dry to obtain recycled glass.

[0089] Comparative Example 1

[0090] This comparative example provides a method for recycling waste photovoltaic modules. The difference from Example 1 is that no wetting liquid is applied in S2. Instead, the module is kept warm under the same temperature and time conditions, and then a stripping load is directly applied to strip the backsheet. Other operating steps and process parameters are exactly the same as in Example 1.

[0091] Comparative Example 2

[0092] This comparative example provides a method for recycling waste photovoltaic modules. The difference from Example 1 is that in S3, only a composite solvent composed of propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol is used, and the catalyst stannous octoate is not added. Other operating steps and process parameters are exactly the same as in Example 1.

[0093] Comparative Example 3

[0094] This comparative example provides a method for recycling waste photovoltaic modules. The difference from Example 1 is that in S3, the coating method is not used. Instead, the second pre-treated waste modules are placed in the same reaction solution and processed under the same temperature and time conditions. Other operation steps and process parameters are exactly the same as in Example 1.

[0095] Comparative Example 4

[0096] This comparative example provides a method for recycling waste photovoltaic modules. The difference from Example 1 is that the composition of the silver leaching solution, the solid-liquid ratio, the temperature and time are kept unchanged in S4, but the local atomized spraying is replaced by immersing the entire battery cell with the exposed silver grid lines in the silver leaching solution. Other operating steps and process parameters are exactly the same as in Example 1.

[0097] The performance of the waste photovoltaic modules from Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows:

[0098] Take waste fluorine-containing backsheet photovoltaic modules from the same batch, model, and service condition, cut them into samples of the same size, set no less than 3 parallel samples in each group, and test them after placing them at room temperature for 24 hours.

[0099] Backsheet peeling integrity test: For the sample after completing step S2, the peeled backsheet is laid flat and photographed. Image analysis software is used to calculate the ratio of the area of ​​the largest continuous backsheet sheet to the area of ​​the initial backsheet.

[0100] Interlayer separation residual adhesive rate test: For the sample after completing step S3, perform image analysis on the glass layers after delamination, and count the proportion of residual adhesive area on the glass surface to the total glass area.

[0101] Silver grid line exposure level: The proportion of the area of ​​exposed silver grid lines on the surface of the cell after layering to the total area of ​​the initial silver grid lines.

[0102] Silver leaching selectivity test: The leaching solution after step S4 was filtered, and the silver concentration and the concentrations of silicon and aluminum impurities in the silver-rich leaching solution were determined by ICP-OES. The mass concentration ratio of silver to silicon and aluminum was calculated, i.e., m. 银 / (m 硅 +m 铝 The higher this ratio, the fewer impurities are leached and the better the selectivity.

[0103] Fluorine residue test on recycled glass surface: The recycled glass surface after cleaning in step S5 is subjected to ultrasonic extraction with deionized water, and the fluorine ion content in the extract is measured and converted into fluorine residue per unit area.

[0104] The test results are shown in Table 1.

[0105] Table 1 Performance test results of waste photovoltaic modules in Examples 1-4 and Comparative Examples 1-4

[0106]

[0107] As shown in Table 1, the test results of Example 1 and Comparative Example 1 reveal that in S2, without the application of wetting liquid, the interface between the backsheet and the encapsulant lacks solvent wetting, resulting in reduced interfacial tension and localized penetration relaxation. Consequently, the backsheet is more prone to tearing and fragmentation during subsequent heating and mechanical peeling, leading to reduced backsheet peeling integrity. Because the backsheet cannot be completely peeled off beforehand, backsheet debris and interface residues are more likely to remain on the subsequent processing interface, resulting in uneven exposure of the encapsulant. This makes it difficult for the reaction solution in S3 to stabilize along a clear interface, leading to increased dragging and adhesion of the encapsulant on the glass surface, thus increasing the interlayer separation residual adhesive rate. Simultaneously, encapsulant and backsheet residues can obscure part of the cell surface, making it difficult to fully expose the silver grid lines, thus reducing the degree of silver grid line exposure. Furthermore, in S4, the effective contact area between the silver leaching solution and the target silver grid lines decreases, while the opportunity for contact with non-target attached impurities increases, restricting the directional transfer of silver to the liquid phase and increasing impurity introduction, thus reducing silver leaching selectivity. In addition, when the backplate is not fully peeled off, fluorine-containing backplate debris and its interface residues are more likely to migrate and adhere to the glass surface, making subsequent cleaning and removal more difficult. Therefore, the amount of fluorine residue on the recovered glass surface increases, indicating a decrease in glass cleanliness.

[0108] As shown in Table 1, the test results of Example 1 and Comparative Example 2 indicate that in S3, only a composite solvent was used without adding a catalyst. S1 and S2 were the same as in Example 1, and the backsheet pre-peeling process did not change substantially. Therefore, the backsheet peeling integrity was basically similar to that of Example 1. However, in the interface delamination stage, the lack of a catalyst to promote the chemical bonds or local reaction sites at the encapsulant interface meant that the composite solvent mainly exhibited wetting and a certain degree of plasticizing effects, making it difficult to further weaken the interfacial bonding between glass / encapsulant and between the cell and encapsulant. Therefore, the delamination was less complete, and the encapsulant was more likely to remain on the glass surface, leading to an increased interlayer separation residue rate. Because the encapsulant failed to completely detach from the cell surface, a significant area of ​​the silver grid lines remained covered, thus reducing the exposure of the silver grid lines. Insufficient exposure of the silver grid lines directly affects the effective reaction area during subsequent localized spray silver leaching, reducing the selective leaching of silver. Simultaneously, interfacial residues may introduce more non-target components, thus reducing the silver leaching selectivity. In addition, with the increase in encapsulating adhesive residue, trace residual contaminants trapped on the interface are more likely to remain on the glass surface and are not easily removed during subsequent cleaning, thus the amount of residual fluorine on the recycled glass surface also increases.

[0109] As shown in Table 1, the test results of Example 1 and Comparative Example 3 indicate that changing the surface coating in S3 to overall immersion, while keeping S1 and S2 unchanged, resulted in a backsheet peel integrity that was essentially the same as in Example 1. However, overall immersion caused the reaction solution to no longer primarily act on the exposed interface, but instead penetrate a larger area into the encapsulating colloidal phase. This easily led to overall softening, bulk swelling, and colloidal migration of the encapsulating adhesive, weakening the directionality of interface dissociation. Consequently, the encapsulating adhesive was more easily dragged and re-adhered to the glass surface, resulting in a significant increase in the interlayer separation residual adhesive rate. Simultaneously, the increased coverage and re-adhesion of the encapsulating adhesive on the cell surface caused the silver grid lines, which should have been exposed, to be re-covered, further reducing the exposure of the silver grid lines. Due to insufficient exposure of the silver grid lines and a large amount of surface deposits, the effect of the silver leaching solution on the target area in subsequent S4 was limited, while non-target components were more likely to enter the leaching solution along with the surface deposits, thus reducing the silver leaching selectivity. In addition, after the encapsulating adhesive migrates and re-attaches to the surface during overall immersion, the trace amounts of fluorine-containing deposits remaining at the interface are more easily encapsulated by the adhesive phase and remain on the glass surface. Subsequent cleaning is difficult to remove them completely, thus increasing the amount of fluorine residue on the recovered glass surface, indicating a decrease in glass cleanliness.

[0110] As shown in Table 1, the test results of Example 1 and Comparative Example 4 indicate that by changing the localized atomization spray in S4 to overall immersion, and keeping S1 to S3 consistent with Example 1, there were no significant changes in backsheet peeling and interface delamination. Therefore, the backsheet peeling integrity was basically similar to that of Example 1, and the interlayer separation residual adhesive rate was also basically similar. Furthermore, since the exposure state of the silver grid lines at the end of S3 was mainly determined by the preceding delamination, the degree of silver grid line exposure was also basically equivalent to that of Example 1. However, in the silver immersion stage, overall immersion caused the silver leaching solution to come into large-area contact with the non-target areas of the solar cell. The silicon substrate surface and other residual components were more likely to participate in the liquid phase contact process, resulting in a significant increase in the probability of impurity components entering the leaching solution. Although silver could still be leached, the degree of directional enrichment decreased, thus significantly reducing the silver leaching selectivity. Since this comparative example did not change the backsheet peeling, interface delamination, and glass cleaning steps, the source contamination state of the glass surface did not change much. Therefore, the amount of residual fluorine on the recovered glass surface was basically similar to that of Example 1.

[0111] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for recycling waste photovoltaic modules, characterized in that, The recycling method includes: S1: Grooves are made in the edge encapsulation area, the gap between adjacent cells, and the safety area outside the busbar on the back of the waste fluorine-containing backsheet photovoltaic module, so that the cutting edge penetrates the backsheet and enters the encapsulation adhesive layer without touching the cells, solder strips, and glass, thus obtaining the first pre-treated waste module. S2: Apply wetting liquid to the opening and inside of the first pre-treated waste component, apply peeling load after heat preservation treatment, and peel off the back plate in whole piece or large piece to obtain the second pre-treated waste component. S3: The reaction solution is coated onto the surface of the encapsulant exposed by the second pre-treated waste component. After constant temperature treatment, a peel load is applied to separate the glass layer, encapsulant film and cell layer, resulting in a cell with exposed glass layer, encapsulant film and silver grid lines. S4: Prepare a silver leaching solution and spray the silver leaching solution locally onto the exposed silver grid lines of the solar cell, so that the silver leaching solution mainly contacts the silver grid line area. After leaching, remove the silicon substrate to obtain a silver-rich leaching solution. S5: The glass layer is placed in a cleaning solution for cleaning, then rinsed with deionized water and dried to obtain recycled glass.

2. The method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S1, the width of the slot opening is 0.2-1.0mm, and the spacing between slots is 10-30mm.

3. The method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S2: The wetting solution is prepared by mixing dimethyl carbonate, isoparaffin Isopar L, a miscibility aid and sorbitan monooleate. The miscibility aid is propylene glycol methyl ether or propylene glycol methyl ether acetate.

4. The method for recycling waste photovoltaic modules according to claim 3, characterized in that, The mass ratio of dimethyl carbonate, isoparaffin Isopar L, miscibility aid and sorbitan monooleate in the wetting solution is (50-70):(15-35):(5-15):(0.5-3); The wetting solution is used after standing in a sealed container for 20-24 hours. The application rate of the wetting liquid is 150-300 g / m³. 2 ; The insulation treatment temperature is 55-70℃, and the time is 20-50 minutes; The peel load is 0.5-2.0 N / mm.

5. The method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S3, the reaction solution is composed of a composite solvent and a catalyst; The composite solvent is obtained by mixing propylene glycol methyl ether acetate, diethylene glycol butyl ether and ethylene glycol; The catalyst is any one of stannous octoate, zinc acetylacetonate, or zinc isooctanoate.

6. The method for recycling waste photovoltaic modules according to claim 5, characterized in that, The mass ratio of propylene glycol methyl ether acetate, diethylene glycol butyl ether, and ethylene glycol in the composite solvent is (50-70):(20-30):(5-15); The mass ratio of the catalyst to the composite solvent is (0.1-1):

100.

7. The method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S3: The coating amount of the reaction solution is 80-150 g / m². 2 ; The constant temperature treatment is 90-115℃ for 1-3 hours; The peel load is 0.1-1.0 N / mm.

8. A method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S4, the silver leaching solution is obtained by adding ferric sulfate and thiourea to deionized water and adjusting the pH with sulfuric acid; the silver leaching solution is locally sprayed onto the battery cells with exposed silver grid lines by atomization spraying.

9. A method for recycling waste photovoltaic modules according to claim 8, characterized in that, The silver leaching solution contains 0.05-0.15 M iron ions derived from ferric sulfate, 0.2-0.5 M thiourea, and a pH of 1.2-2. The cumulative spray volume of the silver leaching solution to the mass ratio of the exposed solar cell on the silver grid line is (5-15) mL:1 g. The leaching temperature is 25-45℃, and the leaching time is 40-80 minutes.

10. A method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S5, the cleaning solution is prepared by dissolving sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in water and adjusting the pH.

11. A method for recycling waste photovoltaic modules according to claim 10, characterized in that, The mass ratio of sodium carbonate, sodium citrate, and fatty alcohol polyoxyethylene ether in the cleaning solution is (2-5):(1-3):(0.2-1.0); The total mass fraction of the cleaning solution is 2%-8%, and the pH is 9-11.

12. The method for recycling waste photovoltaic modules according to claim 1, characterized in that, In S5, The mass-to-volume ratio of the glass layer to the cleaning solution is 1 kg:(5-15) L; The cleaning temperature is 50-70℃, the ultrasonic frequency is 30-40kHz, and the cleaning time is 10-30min.

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