Photovoltaic module dissociation method based on freezing-cementing dual force transfer mechanism

Abstract

The invention discloses a photovoltaic module dissociation method based on a freezing-cementing dual force transfer mechanism. The method comprises the following steps: firstly, cutting a module into small blocks and immersing the small blocks into a special seepage system; the seepage system is an oil-in-water type emulsion composed of silica sol, grease, a functional additive and a water phase, the content of the silica sol is 10-30 wt%, and the content of the grease is 5-15 wt%. Then, the soaked assembly block is subjected to at least one time of freezing and thawing cycle treatment, and the cycle comprises the steps that the assembly is cooled to 80 DEG C below zero to 25 DEG C below zero, and heat preservation is conducted; and then rapidly raising the temperature to 40-80 DEG C at a speed of 30-50 DEG C / min for thermal shock, and expanding cracks by using thermal mismatch stress. And finally, obtaining complete glass, a battery piece, a back plate and an EVA (Ethylene Vinyl Acetate) adhesive film through mechanical separation. Efficient and low-temperature dissociation of the assembly is achieved through the physical synergistic effect, the dissociation rate exceeds 90%, the problems of high energy consumption of a traditional pyrolysis method, toxicity of an organic solvent method and low value of a mechanical method are effectively solved, and the method has the advantages of being environmentally friendly, high in material recovery value and simple and convenient in process.

Description

Technical Field

[0001] This invention relates to the field of resource recycling technology for waste photovoltaic modules, and more specifically, to a method for disintegrating photovoltaic modules based on a freezing-binding dual force transfer mechanism. Background Technology

[0002] Photovoltaic modules are core components in solar energy utilization systems. With the continuous increase in global photovoltaic installed capacity, a large number of early-installed modules are gradually entering the retirement stage. It is predicted that by 2030, the cumulative amount of waste photovoltaic modules globally will reach millions of tons. If they cannot be effectively recycled and processed, it will cause serious resource waste and environmental burden. Waste photovoltaic modules mainly consist of tempered glass, ethylene-vinyl acetate copolymer (EVA) film, crystalline silicon cells, backsheets, metal grids, and aluminum frames. Among these, glass and cells have high economic recycling value. However, the EVA film acts as an adhesive in the module, tightly bonding the glass and cells, becoming a key obstacle to effective separation of the layers and a major technical bottleneck for the resource utilization of waste modules.

[0003] Currently, the disassembly and recycling of waste photovoltaic modules mainly employs methods such as pyrolysis, organic swelling, and mechanical crushing. Pyrolysis separates the glass from the solar cells by decomposing EVA at high temperatures, but this method is extremely energy-intensive and involves corrosive and toxic gas emissions. Furthermore, the high temperatures damage the integrity of the solar cells and silver grid structure, affecting their reuse value. Organic swelling typically uses solvents such as toluene, NMP (N-methylpyrrolidone), and DMF (dimethylformamide) to swell EVA, achieving peeling even at lower temperatures. However, these solvents are highly toxic, flammable, explosive, and emit high levels of volatile organic compounds (VOCs), and solvent recovery is difficult, posing significant environmental risks. Mechanical crushing, on the other hand, physically separates the materials after crushing the module. While the process is simple, it irreversibly damages the glass and solar cell structure, limiting their use to low-value recyclable materials and resulting in low overall recycling value. In addition, some studies have proposed improved methods such as chemical-mechanical combination and low temperature-chemical synergy to try to improve the separation rate while reducing energy consumption. However, problems such as high energy consumption, strong dependence on chemicals, incomplete separation, and poor process stability still exist. Especially in application scenarios that pursue the complete recycling of glass and battery cells, existing technologies are difficult to balance separation efficiency, material integrity, and environmental safety.

[0004] In summary, existing technologies for dismantling spent photovoltaic modules generally suffer from drawbacks such as high energy consumption, heavy environmental burden, low material recycling value, and poor process controllability, making it difficult to achieve green, economical, and efficient resource utilization. Therefore, there is an urgent need for a new dismantling method that is low-energy, environmentally friendly, and can maintain the structural integrity of the glass and solar cells to promote the high-value recycling and reuse of spent photovoltaic modules. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a photovoltaic module dissociation method based on a freezing-binding dual force transfer mechanism, so as to solve the problems of high energy consumption, high environmental risk and low value of recycled materials in the prior art.

[0006] To overcome the shortcomings of the prior art, this invention provides a photovoltaic module dissociation method based on a freeze-cement dual force transfer mechanism, comprising the following steps: S1: Component pretreatment and cutting: Remove the aluminum frame and junction box of the waste photovoltaic module and cut the module into small pieces; S2: Immersion in permeate: Immerse the component block in the permeate system at 20–60 °C for 5–30 minutes to allow the permeate to penetrate the interface layers of glass / EVA, cell / EVA, and backsheet / EVA. The permeation system includes silica sol, oil, functional additives and an aqueous phase, forming an oil-in-water emulsion structure. S3: Freeze-thaw cycle treatment: The component block soaked in the seepage solution is subjected to at least one freeze-thaw cycle; the freeze-thaw cycle includes: S3a: Freezing and curing: Cool the module block to -80 ℃ to -25 ℃ and hold for 1-10 minutes; S3b: Thermal shock: The frozen component block is rapidly heated to 40-80 ℃ at a rate of 30-50 ℃ / min and held at that temperature for 2-5 minutes; S4: Layering and recycling: Mechanically separate the layers of the component that have undergone the freeze-thaw cycle treatment to obtain the dissociated glass, battery cells, backsheet and EVA film.

[0007] This invention, based on a freeze-thaw dual force transfer mechanism, creatively employs a ternary permeation system composed of an aqueous phase, silica sol, and grease, compared to existing technologies. Through a freeze-thaw cycle process, it achieves a synergistic enhancement of the physical force transfer mechanism. Instead of the destructive methods relying on single high temperatures, solvents, or mechanical forces in existing technologies, it utilizes the synergistic effect of the freeze-thaw force of the aqueous phase, the gelation locking force of the silica sol at low temperatures, and the flexible stress transmission of the grease on the EVA interface. This synergistic effect allows for the generation and maintenance of strong, uniform, and durable interfacial stress sufficient to cause EVA adhesive layer failure under low-temperature conditions. The aqueous phase is the main component... The SiO2 gels at low temperatures to form an inorganic framework that locks in stress during freezing expansion. Grease improves wetting, adhesion, and stress distribution. Subsequent thermal shock utilizes the difference in the thermal expansion coefficients of the materials to effectively propagate and connect the microcracks generated during the freezing stage. This invention, through a specific permeation composition (silica sol, grease, and additives) and at least one freeze-thaw cycle, achieves a dissociation rate greater than 90% while maintaining over 90% integrity of the glass and solar cells. This solves the problems of high energy consumption, environmental risk, and low recycling value mentioned in the prior art, achieving the goal of green and high-value recycling of waste photovoltaic modules. Furthermore, with a concentration of 30-50... Rapidly heating to 40-80 ℃ at a rate of ℃ / min can generate thermal mismatch stress. During the rapid heating process, different material layers such as glass, cells, backsheet and EVA in the module will generate strong thermal mismatch stress due to the significant difference in thermal expansion coefficients. This thermally induced shear stress generated by rapid heating is the key driving force. It combines with the microcracks pre-set during the S3a freezing stage to form a synergistic effect, thereby efficiently promoting the propagation and penetration of interface cracks, and finally achieving complete delamination of each layer of the module.

[0008] As a preferred embodiment, in step S1, the area of ​​the small piece is between 5×5 cm and 30×30 cm.

[0009] Compared with existing technologies, the above-mentioned technical solution can further shorten the path of the permeate to the interfaces of each layer inside the component. By cutting large-sized components into small pieces with an area of ​​5×5 cm to 30×30 cm, the contact area between the permeate and the interface layer is increased, and the distance that the liquid needs to diffuse laterally is reduced. This improves the efficiency and uniformity of the permeate wetting the EVA film at the interface, laying a solid foundation for the effective transfer of freeze-thaw force and adhesive force in subsequent steps.

[0010] As a preferred embodiment, in step S2, based on the total weight of the permeation system, the content of the silica sol is 10-30 wt%, and the content of the oil is 5-15 wt%.

[0011] Compared with existing technologies, the above technical solution establishes the foundation for a dual force transfer mechanism of freezing and solidification. In the range of 10-30 wt% silica sol, a sufficiently rigid three-dimensional inorganic skeleton can be formed at low temperatures to effectively lock the frost heave stress, while avoiding the system's viscosity from being too thick due to excessive content, which would affect penetration. In the range of 5-15 wt% grease, a continuous flexible support layer can be formed at the interface, which can uniformly distribute the load and prevent stress concentration from causing material brittleness, thus achieving the optimal synergy of the functions of the aqueous phase, silica sol and grease.

[0012] As a preferred embodiment, the content of the silica sol is 15-25 wt%, and the content of the oil is 7-12 wt%.

[0013] Compared with existing technologies, the above technical solution further optimizes the ratio balance of each phase based on the above synergistic mechanism. Within the above range, the skeleton formation ability of silica sol and the stress homogenization effect of grease are optimally matched, and the aqueous phase can also maintain the maximum practical freeze-thaw volume. The ratio of rigid and flexible components in the force transmission system is further finely controlled, the efficiency of interfacial stress transmission is further improved, and the dissociation process is more efficient and stable.

[0014] As a preferred embodiment, in step S2, the oil is selected from at least one of vegetable oil, triglycerides, polyethylene glycol, and silicone oil.

[0015] Compared with existing technologies, the above technical solution provides a flexible phase with suitable coagulation properties and chemical stability. The selected oils (including vegetable oils, triglycerides, polyethylene glycol, and silicone oils) can effectively thicken or coagulate at low temperatures, thereby forming a non-rigid flexible film at the interface. However, the film itself does not undergo phase change expansion, ensuring uniform stress transmission rather than competition. At the same time, the above substances have good compatibility with silica sol and EVA interfaces, and are not prone to component separation or corrosion of materials.

[0016] As a preferred embodiment, in step S2, the functional additive includes one or more of sodium dodecyl sulfate, sodium chloride, and isopropanol. Based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.2-1.0 wt%, and the content of sodium chloride is 10-20 wt%; based on the total volume of the permeate system, the volume content of isopropanol is 1-30% v / v.

[0017] Compared with existing technologies, the above-mentioned technical solution further precisely controls the physicochemical properties of the permeate system through the synergistic effect of multiple additives: Sodium dodecyl sulfate, as an anionic surfactant, can effectively reduce interfacial tension and stabilize the structure of the oil-in-water emulsion at a content of 0.2-1.0 wt%, preventing the separation of oil and water phases; Sodium chloride, at a concentration range of 10-20 wt%, can control the freezing point of the system to the applicable range (-25℃ to -40℃) and further optimize the ice crystal formation kinetics, ensuring sufficient freeze-thaw force and making the process easy to implement in conventional industrial refrigeration equipment; Isopropanol, as a co-solvent and penetrant, can further reduce the surface tension of the liquid and accelerate the penetration of the permeate into the hydrophobic EVA interface layer.

[0018] As a preferred embodiment, based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.5 wt%, and the content of sodium chloride is 12-18 wt%; based on the total volume of the permeate system, the volume content of isopropanol is 1-20% v / v.

[0019] Compared with existing technologies, the above-mentioned technical solution achieves an optimal balance of various performance parameters on the basis of the functions of the additives. Within the above-mentioned range and fixed values, sodium dodecyl sulfate can achieve emulsion stability with the lowest effective dosage; the concentration of sodium chloride can maintain the operating temperature within the range of efficient operation of conventional industrial refrigeration equipment (approximately -30°C), while avoiding excessive inhibition of ice crystal growth due to excessive salinity, which would lead to a decrease in freeze-thaw resistance; and the dosage of isopropanol ensures the penetration-promoting effect while controlling volatility and cost.

[0020] As a preferred embodiment, in step S3a, when the permeate system contains 10-20 wt% sodium chloride, the freezing temperature is controlled within the range of −25 to −40 ℃, and the holding time is 1-10 minutes.

[0021] Compared with existing technologies, the above-mentioned technical solution can lower the freezing point of the aqueous phase by adding sodium chloride, enabling the system to freeze and generate sufficient frost heave force at relatively high temperatures (-25℃ to -40℃). This reduces the dependence on deep freezing equipment and energy consumption. At the same time, controlling the freezing temperature within this range avoids a sharp increase in energy consumption due to excessively low temperatures and also prevents insufficient frost heave force due to excessively high temperatures.

[0022] As a preferred embodiment, in step S4, after the mechanical separation is completed, the recycled material is further cleaned with deionized water at 80 °C.

[0023] Compared with existing technologies, the above technical solution can effectively remove residual seepage components from the surface of recycled materials, improve product purity, and effectively dissolve or soften residual silica sol gel at 80°C. It can also dissolve and wash away grease and water-soluble salts adhering to the surfaces of glass and battery cells. The 80°C temperature can ensure cleaning efficiency while being far below the threshold that may cause thermal damage to battery cells or glass. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of the photovoltaic module dissociation method based on the freezing-bonding dual force transfer mechanism of the present invention. Figure 2 This is a diagram illustrating the implementation effect of Example 1; Figure 3 This is a diagram illustrating the implementation effect on a scale. Detailed Implementation

[0025] First, those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0026] This invention provides a photovoltaic module dissociation method based on a freeze-cement dual force transfer mechanism, comprising the following steps: S1: Component pretreatment and cutting: Remove the aluminum frame and junction box of the waste photovoltaic module and cut the module into small pieces to shorten the penetration path and improve the efficiency of the seepage liquid entering the interface layer; S2: Immersion in permeate: Immerse the component block in the permeate system at 20–60 °C for 5–30 minutes to allow the permeate to penetrate the interface layers of glass / EVA, cell / EVA, and backsheet / EVA. The permeation system includes silica sol, oil, functional additives and an aqueous phase, forming an oil-in-water emulsion structure. The role of silica sol is to form an inorganic framework at low temperatures, which is responsible for "solidification and locking". The function of grease: It does not cause volume expansion at low temperatures, but is only used to improve wetting and stress uniformity and enhance interfacial retention; Aqueous phase: Used to balance the seepage system to 100%, and is the main source of frost heave; S3: Freeze-thaw cycle treatment: The component block soaked in the seepage solution is subjected to at least one freeze-thaw cycle; the freeze-thaw cycle includes: S3a: Freezing and Gel Coagulation: Cool the module block to -80 ℃ to -25 ℃ and hold for 1-10 minutes; during this stage, the aqueous phase freezes to provide core frost heave force; the silica sol gels simultaneously to build a three-dimensional rigid skeleton to lock and transfer stress; at the same time, the grease phase thickens and forms a flexible support layer at the interface, thereby evenly distributing the load and effectively suppressing brittle fracture caused by local stress concentration.

[0027] S3b: Thermal shock: The frozen component block is rapidly heated to 40-80 ℃ at a rate of 30-50 ℃ / min and held at that temperature for 2-5 minutes. During this stage, the glass, battery cells, backsheet, and EVA materials generate strong thermal mismatch stress due to the significant difference in their coefficients of thermal expansion. Thermoinduced shear stress, as a key driving force, combines with the microcrack system pre-set by the freeze-swell-cementation mechanism in the freezing stage S3a to form a synergistic effect, thereby efficiently promoting the propagation and penetration of interface cracks, ultimately achieving complete delamination.

[0028] S4: Layering and recycling: Mechanically separate the layers of the component that have undergone the freeze-thaw cycle treatment to obtain the dissociated glass, battery cells, backsheet and EVA film.

[0029] As a preferred embodiment, in step S1, the area of ​​the small piece is between 5×5 cm and 30×30 cm.

[0030] As a preferred embodiment, in step S2, based on the total weight of the permeation system, the content of the silica sol is 10-30 wt%, and the content of the oil is 5-15 wt%.

[0031] As a preferred embodiment, the content of the silica sol is 15-25 wt%, and the content of the oil is 7-12 wt%.

[0032] As a preferred embodiment, in step S2, the oil is selected from at least one of vegetable oil, triglycerides, polyethylene glycol, and silicone oil.

[0033] As a preferred embodiment, in step S2, the functional additive includes one or more of sodium dodecyl sulfate, sodium chloride, and isopropanol. Based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.2-1.0 wt%, and the content of sodium chloride is 10-20 wt%; based on the total volume of the permeate system, the volume content of isopropanol is 1-30% v / v.

[0034] Sodium dodecyl sulfate is used to reduce interfacial tension and stabilize the O / W emulsion system; isopropanol is used to further reduce surface tension and accelerate wetting; while sodium chloride is used to regulate freezing point and freezing kinetics, facilitating implementation at -25 to -40°C. However, excessive salinity will compress the ice volume fraction, so the concentration of sodium chloride should be avoided to be >20 wt%. The permeate system is preferably formulated as an oil-in-water emulsion, which can simultaneously meet two key requirements: the aqueous phase, as the continuous phase, occupies the main body of the system, ensuring that sufficient ice crystals are generated during the freezing stage, thereby providing ample frost heave force; while the oil phase is stably dispersed in the aqueous phase in the form of microdroplets, which can fully wet the interfaces of each layer by utilizing its excellent spreadability, and can also achieve uniform stress transmission and distribution during freezing and solidification.

[0035] As a preferred embodiment, based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.5 wt%, and the content of sodium chloride is 12-18 wt%; based on the total volume of the permeate system, the volume content of isopropanol is 1-20% v / v.

[0036] As a preferred embodiment, in step S3a, when the permeate system contains 10-20 wt% sodium chloride, the freezing temperature is controlled within the range of −25 to −40 ℃, and the holding time is 1-10 minutes.

[0037] As a preferred embodiment, in step S4, after the mechanical separation is completed, the recycled material is further cleaned with deionized water at 80 °C.

[0038] This invention achieves low-temperature, high-efficiency dissociation of waste photovoltaic modules based on a "freezing-solidification dual force transfer mechanism." The core of the method lies in employing a specially formulated percolation system composed of silica sol, grease (flexible phase), and functional additives. Through the synergistic effect of three factors—the freezing of the aqueous phase generating frost heave force, the low-temperature gelation of the silica sol forming inorganic framework locking stress, and the grease improving wetting and uniformly distributing stress—a cyclical process of cutting, percolation immersion, low-temperature freezing, and rewarming thermal shock induces and propagates cracks at the interlayer interfaces of the module, thereby achieving complete separation of the glass, cells, backsheet, and EVA film. Compared to existing technologies, this method eliminates the high-temperature energy consumption and toxic gas emissions of traditional pyrolysis methods, and avoids the toxicity and environmental pollution problems of organic solvent methods. Its process conditions are mild, energy consumption is significantly reduced, and there is no thermal damage or chemical corrosion to the cells and silver grid lines during processing, preserving the material's reuse value. The dissociation rate of this invention exceeds 90%, with high integrity retention of the glass and cells, achieving high-value recycling of module materials. Meanwhile, the raw materials for the leachate system are widely available and inexpensive, the overall process is simple and environmentally friendly, and it has excellent prospects for industrial application.

[0039] The following are embodiments incorporating specific data to further elaborate on the above-described technical solutions of the present invention: Example 1 This embodiment provides a photovoltaic module dissociation method based on a freeze-cement dual force transfer mechanism, including the following steps: S1: Component Preprocessing and Cutting Cut the discarded photovoltaic modules, after removing the frames and junction boxes, into small pieces of 15 cm × 15 cm.

[0040] S2: Immersion in seepage Preparation of the permeation system: 20 wt% SiO2 sol, 10 wt% vegetable oil (rapeseed oil), 0.5 wt% sodium dodecyl sulfate (SDS), with the balance being deionized water. Immerse the module block in this permeation system at 40 °C for 15 minutes.

[0041] S3: Freeze-thaw cycle processing S3a: Freezing and curing: Place the soaked component block in a freezing environment of −60 °C for 5 minutes.

[0042] S3b: Thermal shock: The frozen component block is rapidly transferred to 60 ℃ hot water, and then rapidly heated at a rate of 30-50 ℃ / min for 3 minutes.

[0043] This freeze-thaw cycle (S3a and S3b) is repeated 3 times.

[0044] S4: Stratification and Recycling After recycling, the module glass, solar cells, EVA film, and backsheet were completely separated. Each layer was mechanically peeled off and then washed with 80°C deionized water. The total mass of all layers was 328 g, the original module mass was 340 g, the separation rate was 96.3%, and the integrity of the glass and solar cells exceeded 90%.

[0045] Desorption rate is defined as: the sum of the weights of the stripped layers / the weight of the recycled components before processing × 100%.

[0046] Example 2 This embodiment provides a photovoltaic module dissociation method based on a freeze-cement dual force transfer mechanism, including the following steps: S1: Component Preprocessing and Cutting Cut the discarded components into small pieces of 20 cm × 20 cm.

[0047] S2: Immersion in seepage Prepare the permeate system as follows: 15 wt% SiO2 sol, 8 wt% polyethylene glycol (PEG600), 15 wt% sodium chloride (NaCl), 0.3 wt% sodium dodecyl sulfate (SDS), with the balance being deionized water. Immerse the module block in this permeate system at 30 °C for 20 minutes.

[0048] S3: Freeze-thaw cycle processing S3a: Freezing and curing: Place the soaked component block in a freezer at −30 °C and keep it for 10 minutes.

[0049] S3b: Thermal shock: The frozen component block is heated to 50 ℃ hot water, and then rapidly heated at a rate of 30-50 ℃ / min for 2 minutes.

[0050] (This embodiment involved one freeze-thaw cycle.) S4: Stratification and Recycling After processing, each layer of the component was clearly separated. Each layer was mechanically peeled off and then washed with 80°C deionized water. The total mass of the recovered material was 572 g, while the original component weighed 600 g, resulting in a dissociation rate of 95.3%.

[0051] Example 3 S1: Component Preprocessing and Cutting Cut the discarded components into small pieces of 10 cm × 10 cm.

[0052] S2: Immersion in seepage Prepare the permeate system as follows: 25 wt% SiO2 sol, 12 wt% vegetable oil (olive oil), 10% v / v isopropanol (IPA), 0.5 wt% sodium dodecyl sulfate (SDS), and the balance being deionized water. Immerse the module block in this permeate system at 50 °C for 10 minutes.

[0053] S3: Freeze-thaw cycle processing S3a: Freezing and curing: Transfer the soaked component block to a -70 °C freeze dryer and cool for 5 minutes.

[0054] S3b: Thermal shock: Transfer the frozen component block to a 70 ℃ hot air environment, and then rapidly heat it up at a rate of 30-50 ℃ / min for 3 minutes.

[0055] (This embodiment involved one freeze-thaw cycle.) S4: Stratification and Recycling The processed module layers were mechanically separated and washed with 80 °C deionized water. The final recovered mass was 139 g, the original module mass was 150 g, and the dissociation rate was 92.6%.

[0056] Comparative Example S1: Component Preprocessing and Cutting Select waste photovoltaic modules from the same source as in Example 1, remove the frames and junction boxes, and cut them into small pieces of 15 cm × 15 cm.

[0057] (Step S2: Immersion in seepage solution omitted) S3: Freeze-thaw treatment S3a: Freezing: Place the component block directly into a freezer at −40 °C and freeze for 20 minutes.

[0058] S3b: Thermal shock: Remove the frozen component block and place it in 60 ℃ hot water for 5 minutes.

[0059] (The comparison was subjected to one freeze-thaw cycle) S4: Stratification and Recycling After treatment, an attempt was made to mechanically separate the layers of the module. The results showed that there was some delamination between the module layers, but the separation was incomplete. Most of the EVA film remained and adhered to the glass or cell surface, and the backsheet was not completely separated. The final recycled mass was 216 g, the original module mass was 342 g, and the dissociation rate was only 63.1%.

[0060] like Figure 1-3 As shown, Figure 1 This is a flowchart of the overall process of the photovoltaic module dissociation method based on the freezing-solidification dual force transmission mechanism of the present invention. It includes module pretreatment and cutting, soaking in a special liquid permeation system, freezing and solidification stage, thermal shock stage, and the final mechanical delamination and material recycling steps. The method of the present invention forms frost heave force and silica sol gel skeleton at low temperature after the liquid permeates into the interface, which, together with the flexible stress transmission of grease, promotes the generation of interface microcracks. Figure 2 This is a processing effect diagram of Example 1. Figure 2 In the experiment, after three freeze-thaw cycles, the adhesive layer between the module glass, battery cells, EVA film and backsheet was completely ineffective. The four-layer structure was peeled off in one piece, cleanly and with high integrity. There were no obvious residues at the interface, which verified the high efficiency of the seepage system and freeze-thaw synergy in destroying the interface. Figure 3 As a comparative example of the treatment effect, without liquid soaking and relying solely on simple freeze-thaw treatment, the comparative component still had a large area of ​​EVA film residue between the layers, and the glass and battery cells were severely adhered, and the backsheet separation was incomplete. Overall, it showed an incomplete delamination and poor interface peeling quality. This further demonstrates the key role of the liquid soaking system and the freeze-adhesion dual force transfer mechanism described in this invention in promoting interface debonding, improving dissociation efficiency and material integrity.

[0061] In summary, the comparison results between the above embodiments and comparative examples show that the specially designed permeation system used in this invention is the key factor determining the dissociation effect. In Examples 1-3, by using a ternary permeation system composed of silica sol, grease, and functional additives, combined with a freeze-thaw cycle process, a high dissociation rate of over 92.6% was achieved, while maintaining the integrity and cleanliness of the glass and the battery cell. In contrast, under the same pretreatment and similar freeze-thaw conditions, the dissociation rate of the comparative example plummeted to 63.1% simply because the permeation soaking step was omitted, and a large amount of EVA film remained, resulting in extremely incomplete separation. This further proves that the core permeation system of this invention and its triggered "freeze-solid dual force transmission mechanism" are indispensable for achieving efficient and complete interlayer dissociation. Simple physical freeze-thaw cannot effectively destroy the EVA bonding interface, while the synergistic mechanism of this invention can accurately and efficiently achieve this goal.

[0062] In summary, this invention, based on the synergistic effect of aqueous phase (freeze-swell source), silica sol (stress framework), and grease (flexible stress layer) and their specific ratios, successfully solves the problems of high energy consumption, environmental pollution, and low material value faced by existing technologies through a simple freeze-thaw cycle physical process. The advantages of this method include: 1) Low-temperature operation, significantly lower energy consumption than pyrolysis methods; 2) Water-based, far more environmentally friendly than organic solvent methods; 3) Non-destructive separation, with material recycling value far exceeding that of mechanical crushing methods. This invention provides a practical and highly industrializable technical path for the green and high-value recycling of waste photovoltaic modules.

[0063] In the description of this invention, the references to "one embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A photovoltaic module dissociation method based on a freeze-cement dual force transfer mechanism, characterized in that, Includes the following steps: S1: Component pretreatment and cutting: Remove the aluminum frame and junction box of the waste photovoltaic module and cut the module into small pieces; S2: Immersion in permeate: Immerse the component block in the permeate system at 20–60 °C for 5–30 minutes to allow the permeate to penetrate the interface layers of glass / EVA, cell / EVA, and backsheet / EVA. The permeation system includes silica sol, oil, functional additives and an aqueous phase, forming an oil-in-water emulsion structure. S3: Freeze-thaw cycle treatment: The component block soaked in the seepage solution is subjected to at least one freeze-thaw cycle; the freeze-thaw cycle includes: S3a: Freezing and curing: Cool the module block to -80 to -25 ℃ and hold for 1-10 minutes; S3b: Thermal shock: The frozen component block is rapidly heated to 40-80 ℃ at a rate of 30-50 ℃ / min and held at that temperature for 2-5 minutes; S4: Layering and recycling: Mechanically separate the layers of the component that have undergone the freeze-thaw cycle treatment to obtain the dissociated glass, battery cells, backsheet and EVA film.

2. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S1, the area of ​​the small piece is between 5×5 cm and 30×30 cm.

3. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S2, based on the total weight of the permeation system, the content of the silica sol is 10-30 wt%, and the content of the oil is 5-15 wt%.

4. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 3, characterized in that, The content of the silica sol is 15-25 wt%, and the content of the oil is 7-12 wt%.

5. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S2, the oil is selected from at least one of vegetable oil, triglycerides, polyethylene glycol, and silicone oil.

6. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S2, the functional additive includes one or more of sodium dodecyl sulfate, sodium chloride, and isopropanol. Based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.2-1.0 wt%, and the content of sodium chloride is 10-20 wt%. Based on the total volume of the permeate system, the volume content of isopropanol is 1-30% v / v.

7. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 6, characterized in that, Based on the total weight of the permeate system, the content of sodium dodecyl sulfate is 0.5 wt%, and the content of sodium chloride is 12-18 wt%; based on the total volume of the permeate system, the volume content of isopropanol is 1-20% v / v.

8. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S3a, when the permeate system contains 10-20 wt% sodium chloride, the freezing temperature is controlled within the range of −25 to −40 ℃, and the holding time is 1-10 minutes.

9. The photovoltaic module dissociation method based on the freeze-cement dual force transfer mechanism according to claim 1, characterized in that, In step S4, after the mechanical separation is completed, the recycled material is further cleaned with deionized water at 80 °C.

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