Method for green and efficient separation of waste copper-indium-gallium-selenium solar thin film cells

Abstract

The invention relates to the technical field of green recovery and treatment of solid wastes, in particular to a method for green and efficient separation of waste copper-indium-gallium-selenium solar thin film cells, which comprises the following steps of: curling and fixing the waste copper-indium-gallium-selenium solar thin film cells, then removing and fixing, cutting the cells into square sheets with the size of 2 * 2cm, and cutting the square sheets into copper-indium-gallium-selenium solar thin film cells into copper-indium-gallium-selenium solar thin film cells; putting into a beaker filled with deionized water and carrying out ultrasonic treatment; after a certain amount of deionized water is added into the instantaneous differential pressure separator, the battery piece is put into the instantaneous differential pressure separator, and the instantaneous differential pressure separator is started when the temperature and the pressure reach certain conditions. And a waste copper indium gallium selenium solar thin film cell separation product is obtained. According to the method, the waste copper-indium-gallium-selenium solar thin film cell can be efficiently separated within a short time, so that a CIGS layer is exposed, the problems that in the waste copper-indium-gallium-selenium solar thin film cell recycling process, energy consumption is large, pollution is large, the CIGS layer is difficult to leach, valuable metal is difficult to enrich and the like are solved, and the process is green, efficient, simple and suitable for large-scale industrial application.

Description

Technical Field

[0001] The present invention relates to the technical field of green recycling of solid waste, and in particular to a method for green and efficient separation of waste copper indium gallium selenide solar thin-film cells. Background Art

[0002] In recent years, the photovoltaic industry has developed rapidly. According to the latest edition of the World Energy Statistical Yearbook released by the Energy Research Institute in 2023: Solar and wind power generation continued to grow rapidly, reaching a record high of 266 GW. Solar power generation accounted for 72% of new power generation (192 GW). Solar power generation increased by 25%, and renewable energy (excluding hydropower) met 84% of the net increase in electricity demand. As the main force in the transition from global fossil energy to new energy, the photovoltaic industry can basically maintain an annual compound growth rate of about 30%, and the prosperity continues to rise. At present, crystalline silicon photovoltaic modules still dominate the photovoltaic market, but copper indium gallium selenide solar thin-film batteries will account for more and more in the photovoltaic market due to their advantages such as more application scenarios, higher photoelectric conversion efficiency, and lower cost preparation process, and the final market share will reach 50%. By then, a large number of copper indium gallium selenide solar thin-film batteries will face retirement. At present, the research focus is still on the preparation process of copper indium gallium selenide solar thin film cells and the modification of their performance. There are relatively few studies on the separation and recovery of copper indium gallium selenide solar thin film cells. If copper indium gallium selenide solar thin film cells are not separated, it will cause the problem of difficult recovery. According to the existing separation and recovery methods, the separation method has the problems of long separation time, low separation efficiency, high energy consumption, etc. The recovery method has the disadvantages of high energy consumption and high pollution in pyrometallurgical recovery, and long leaching time, large reagent consumption, and generation of harmful waste liquid in wet recovery. Both pyrometallurgical recovery and wet recovery have the pain point that it is difficult to enrich the valuable metals.

[0003] In summary, there is an urgent need to develop a green and efficient method for separating waste copper indium gallium selenide solar thin-film cells, which can not only solve the problems of long separation time, low separation efficiency, and high energy consumption in the existing technology, but also achieve the enrichment of valuable metals, providing great convenience for subsequent recycling. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a green and efficient method for separating waste copper indium gallium selenide solar thin-film cells, which aims to solve the problems of long separation time, low separation efficiency, high energy consumption, etc. in the prior art, while achieving the enrichment of valuable metals, providing great convenience for subsequent recycling.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] A green and efficient method for separating waste copper indium gallium selenide solar thin film batteries comprises the following steps:

[0007] S1: curling and fixing the waste copper indium gallium selenide solar thin-film cells according to a certain curvature, and keeping the curled state for a certain period of time;

[0008] S2: removing the fixing in step S1 and unfolding the thin film battery;

[0009] S3: Observe the thin film battery after the step S2 is unfolded, and cut the gap between the stainless steel substrate and the upper structure into two × Repeat steps S1 to S3 for the 2 cm battery sheet without gaps;

[0010] S4: Place the battery cell in a beaker filled with deionized water, place the beaker in an ultrasonic instrument, and ultrasonicate for a certain period of time;

[0011] S5: placing the battery cell after the ultrasonic treatment in step S4 into an instantaneous pressure difference separator and adding a certain amount of deionized water;

[0012] S6: Run the instantaneous pressure difference separator. When the temperature and pressure reach certain conditions, open the instantaneous pressure difference separator;

[0013] S7: collecting the separated products including: CIGS-PET layer, stainless steel substrate, EVA, PET, and performing vacuum drying on the collected products.

[0014] Furthermore, in step S1, the curvature range of the copper indium gallium selenide solar thin film battery is 4 to 50 μm. -1 , keep the curled state for 30 minutes.

[0015] Furthermore, the curvature range is 20 to 50 m. -1 .

[0016] Furthermore, the part without gaps in step S3 repeats steps S1 to S3, and the curling curvature and the curling state retention time remain the same as when step S1 is first performed.

[0017] Furthermore, in step S4, the ultrasonic treatment time of the battery cell in deionized water is 10 to 60 minutes.

[0018] Furthermore, the ultrasonic time range is 10 to 30 minutes.

[0019] Furthermore, in step S5, 1-10 ml of deionized water is first added into the instantaneous pressure difference separator, and then the battery cells are placed therein.

[0020] Furthermore, the deionized water is 1 to 5 ml.

[0021] Furthermore, in step S6, when the pressure range of the instantaneous pressure difference separator is 1-10 MPa and the temperature reaches 100-350° C., the instantaneous pressure difference separator is turned on.

[0022] Furthermore, when the pressure range is 3-6 MPa and the temperature is 100-300° C., the instantaneous pressure difference separator is turned on.

[0023] Furthermore, in step S7, the vacuum drying temperature is 50° C. and the drying time is 30 min.

[0024] It can be seen from the above technical solution that compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The present invention uses instantaneous pressure difference separation technology to achieve efficient separation of waste copper indium gallium selenide solar thin-film cells, and the separation products obtained include: CIGS-PET layer, stainless steel substrate, EVA, and PET. Compared with traditional separation methods, the separation efficiency is significantly improved, and the whole process is green and harmless, and will not cause environmental burden.

[0026] 2. The present invention realizes the efficient separation of waste copper indium gallium selenide solar thin-film cells through instantaneous pressure difference separation technology, which greatly facilitates the subsequent recycling of valuable metals therein. The present invention exposes the GIGS layer, greatly shortens the wet leaching time, saves a large amount of chemical reagents, and at the same time, the separation of EVA and PET reduces the emission of harmful gases and carbon dioxide generated by pyrometallurgical recycling. Through the instantaneous pressure difference separation technology, the pollution to the atmosphere, water bodies and soil is greatly reduced, providing a new way for the green separation and recycling of photovoltaic industry waste, which has far-reaching significance for environmental protection.

[0027] 3. While realizing the green and efficient separation of waste copper indium gallium selenide solar thin-film batteries, the present invention enriches valuable metals such as copper, indium, gallium and selenium in the batteries, providing high-quality raw materials for subsequent metal refining and recycling, reducing the demand for raw material mining, alleviating the pressure on the consumption of natural resources, and also reducing the cost of material recycling, which helps to promote the sustainable development of the upstream and downstream of the photovoltaic industry chain.

[0028] 4. Compared with traditional separation technology, the instantaneous pressure difference separation process causes minimal physical damage to the thin film material, which means that more materials can be recycled and reused, greatly reducing material loss. This is especially important for high-value copper indium gallium selenide solar thin film cells, because the production cost of such materials is relatively high. Through this technology, not only can the recycling efficiency of materials be effectively improved, but also the economic cost of the entire recycling process can be reduced, thereby bringing better economic benefits to enterprises.

[0029] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 This is the structural diagram of waste copper indium gallium selenide thin film battery;

[0032] Figure 2 This is the SEM characterization picture of the structure of waste copper indium gallium selenide thin film battery;

[0033] Figure 3 This is a separation effect diagram of Example 1;

[0034] Figure 4 This is a separation effect diagram of Example 2;

[0035] Figure 5 This is a separation effect diagram of Example 3;

[0036] Figure 6 This is a separation effect diagram of Example 4;

[0037] Figure 7 This is the separation effect diagram of Comparative Example 1;

[0038] Figure 8 This is the separation effect diagram of Comparative Example 2;

[0039] Fig. 9 This is the separation effect diagram of Comparative Example 3;

[0040] Fig.10 This is the separation effect diagram of Comparative Example 4;

[0041] Fig.11 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example 1

[0044] The waste copper indium gallium selenide solar thin film cells are placed in a curvature of 20m -1Roll it up and fix it, keep it in the rolled state for 30 minutes, then remove the fixation and unfold the thin film battery. Cut the part with gap between the substrate and the upper structure into 2×2cm size battery sheets, and repeat steps S1 to S3 for the part without gap, and keep the curling curvature and the curling state time consistent with the above.

[0045] Place the cell in a beaker filled with deionized water, place the beaker in an ultrasonicator, and perform ultrasonication for 30 minutes. Add 5 ml of deionized water to the instantaneous pressure difference separator, place the cell after ultrasonication in the instantaneous pressure difference separator, and run the instantaneous pressure difference separator. When the pressure reaches 6 MPa and the temperature shows 288°C, turn on the instantaneous pressure difference separator to collect the waste copper indium gallium selenide solar thin film cell separation products, including: CIGS-PET layer, stainless steel substrate, EVA between the bonding substrate and PET, and PET of the encapsulation substrate (such as Figure 3 ).

[0046] According to the measurement, the mass of the 2×2cm cell of the waste copper indium gallium selenide solar thin film battery before separation is 0.2005g, the mass of the CIGS-PET layer obtained after separation is 0.0577g, the mass of the stainless steel substrate is 0.0957g, the mass of the EVA between the bonding substrate and PET is 0.0195g, and the mass of the PET of the encapsulation substrate is 0.0276g. According to the calculation, the stainless steel substrate, the EVA between the bonding substrate and PET, and the PET of the encapsulation substrate account for 71.2% of the mass of the whole cell, which effectively enriches the valuable metals and selenium elements in the cell, and at the same time achieves the purpose of exposing the CIGS layer. The separation effect is as follows: Figure 3 shown.

[0047] Example 2

[0048] The waste copper indium gallium selenide solar thin film cells are placed in a curvature of 30m -1 Roll it up and fix it, keep it in the rolled state for 30 minutes, then remove the fixation and unfold the thin film battery. Cut the part with gap between the substrate and the upper structure into 2×2cm size battery sheets, and repeat steps S1 to S3 for the part without gap, and keep the curling curvature and the curling state time consistent with the above.

[0049] Place the cell in a beaker filled with deionized water, place the beaker in an ultrasonicator, and perform ultrasonic treatment for 25 minutes. Add 4 ml of deionized water to the instantaneous pressure difference separator, place the cell after ultrasonic treatment in the instantaneous pressure difference separator, and run the instantaneous pressure difference separator. When the pressure reaches 5 MPa and the temperature shows 241°C, turn on the instantaneous pressure difference separator to collect the waste copper indium gallium selenide solar thin film cell separation products, including: CIGS-PET layer, stainless steel substrate, EVA between the bonding substrate and PET, and PET of the encapsulation substrate (such as Figure 4 ).

[0050] According to the measurement, the mass of the 2×2cm cell of the waste copper indium gallium selenide solar thin film battery before separation is 0.2018g, the mass of the CIGS-PET layer obtained after separation is 0.0573g, the mass of the stainless steel substrate is 0.0967g, the mass of the EVA between the bonding substrate and PET is 0.0197g, and the mass of the PET of the encapsulation substrate is 0.0281g. According to the calculation, the stainless steel substrate, the EVA between the bonding substrate and PET, and the PET of the encapsulation substrate account for 71.6% of the mass of the whole cell, which effectively enriches the valuable metals and selenium elements in the cell, and at the same time achieves the purpose of exposing the CIGS layer. The separation effect is as follows: Figure 4 shown.

[0051] Example 3

[0052] The waste copper indium gallium selenide solar thin film cells are placed in a curvature of 40m -1 Roll it up and fix it, keep it in the rolled state for 30 minutes, then remove the fixation and unfold the thin film battery. Cut the part with gap between the substrate and the upper structure into 2×2cm size battery sheets, and repeat steps S1 to S3 for the part without gap, and keep the curling curvature and the curling state time consistent with the above.

[0053] Place the cell in a beaker filled with deionized water, place the beaker in an ultrasonicator, and perform ultrasonication for 20 minutes. Add 3 ml of deionized water to the instantaneous pressure difference separator, place the cell after ultrasonication in the instantaneous pressure difference separator, and run the instantaneous pressure difference separator. When the pressure reaches 4 MPa and the temperature shows 218°C, turn on the instantaneous pressure difference separator to collect the waste copper indium gallium selenide solar thin film cell separation products, including: CIGS-PET layer, stainless steel substrate, EVA between the bonding substrate and PET, and PET of the encapsulation substrate (such as Figure 5 ).

[0054] According to the measurement, the mass of the 2×2cm cell of the waste copper indium gallium selenide solar thin film battery before separation is 0.2047g, the mass of the CIGS-PET layer obtained after separation is 0.0594g, the mass of the stainless steel substrate is 0.0970g, the mass of the EVA between the bonding substrate and PET is 0.0196g, and the mass of the PET of the encapsulation substrate is 0.0287g. According to the calculation, the stainless steel substrate, the EVA between the bonding substrate and PET, and the PET of the encapsulation substrate account for 71.0% of the mass of the whole cell, which effectively enriches the valuable metals and selenium elements in the cell, and at the same time achieves the purpose of exposing the CIGS layer. The separation effect is as follows: Figure 5 shown.

[0055] Example 4

[0056] The waste copper indium gallium selenide solar thin film cells are placed in a curvature of 50m -1 Roll it up and fix it, keep it in the rolled state for 30 minutes, then remove the fixation and unfold the thin film battery. Cut the part with gap between the substrate and the upper structure into 2×2cm size battery sheets, and repeat steps S1 to S3 for the part without gap, and keep the curling curvature and the curling state time consistent with the above.

[0057] Place the cell in a beaker filled with deionized water, place the beaker in an ultrasonicator, and perform ultrasonication for 20 minutes. Add 2 ml of deionized water to the instantaneous pressure difference separator, place the cell after ultrasonication in the instantaneous pressure difference separator, and run the instantaneous pressure difference separator. When the pressure reaches 3 Mpa and the temperature shows 188 ° C, turn on the instantaneous pressure difference separator to collect the waste copper indium gallium selenide solar thin film battery separation products including: CIGS-PET layer, stainless steel substrate, EVA between the bonding substrate and PET, and PET of the packaging substrate (such as Figure 6 ).

[0058] According to the measurement, the mass of the 2×2cm cell of the waste copper indium gallium selenide solar thin film battery before separation is 0.2032g, the mass of the CIGS-PET layer obtained after separation is 0.0582g, the mass of the stainless steel substrate is 0.0968g, the mass of the EVA between the bonding substrate and PET is 0.0197g, and the mass of the PET of the encapsulation substrate is 0.0285g. According to the calculation, the stainless steel substrate, the EVA between the bonding substrate and PET, and the PET of the encapsulation substrate account for 71.3% of the mass of the whole cell, which effectively enriches the valuable metals and selenium elements in the cell, and at the same time achieves the purpose of exposing the CIGS layer. The separation effect is as follows: Figure 6 shown.

[0059] Comparative Example 1

[0060] This comparative example provides a green and efficient method for separating waste copper indium gallium selenide solar thin film cells. The method includes step S1 in which the curling curvature is 18m -1 Except for the above, the other conditions are exactly the same as those in Example 1. When the curvature is less than the preferred parameter range, the CIGS-PET layer is separated from the stainless steel substrate, the PET package on the back of the stainless steel substrate falls off, but the EVA is still adhered to the stainless steel substrate and cannot be separated. The separation effect is as follows: Figure 7 shown.

[0061] Comparative Example 2

[0062] This comparative example provides a green and efficient method for separating waste copper indium gallium selenide solar thin-film cells. Except that the ultrasonic time in step S4 is 8 minutes, the other conditions are exactly the same as those in Example 1. When the ultrasonic time is less than the preferred parameter range, the CIGS-PET layer is separated from the stainless steel substrate, and the PET package on the back of the stainless steel substrate falls off, but the EVA is still adhered to the stainless steel substrate and cannot be separated. There is a tendency for EVA to separate from the stainless steel substrate, but it cannot be completely separated, and part of the cell sheet remains on the stainless steel substrate. The separation effect is as follows: Figure 8 shown.

[0063] Comparative Example 3

[0064] This comparative example provides a green and efficient method for separating waste copper indium gallium selenide solar thin-film batteries. Except for adding 0.5 ml of deionized water in step S5, the other conditions are exactly the same as those in Example 1. When the amount of deionized water added is less than the preferred parameter range, the CIGS-PET layer is separated from the stainless steel substrate, and the PET package on the back of the stainless steel substrate falls off, but the EVA is still adhered to the stainless steel substrate and cannot be separated. There is a tendency for EVA to separate from the stainless steel substrate, but it cannot be completely separated. The separation effect is stronger than that of comparative example 2, and part of the battery cell remains on the stainless steel substrate. The separation effect is as follows: Fig. 9 shown.

[0065] Comparative Example 4

[0066] This comparative example provides a green and efficient method for separating waste copper indium gallium selenide solar thin-film cells. The method is exactly the same as Example 1 except that the pressure in step S6 is 2.5 MPa. When the pressure is less than the preferred parameter range, the edge of the CIGS-PET layer is warped and cannot be separated from the stainless steel substrate. The warped portion is sheared off, and the PET package on the back of the stainless steel substrate does not fall off. The EVA is still adhered to the stainless steel substrate and cannot be separated. The separation effect is as follows: Fig.10 shown.

[0067] It should also be noted that when the experimental parameters are greater than the preferred parameter range, the separation products can be completely separated, but the entire process consumes more energy. Therefore, it is appropriate to separate waste copper indium gallium selenide solar thin-film cells within the given preferred parameter range.

[0068] In summary, the present invention proposes a green and efficient method for separating waste copper indium gallium selenide solar thin-film batteries, which can separate waste copper indium gallium selenide solar thin-film batteries in a green and efficient manner to expose the CIGS layer, thereby solving the problems of high energy consumption, high pollution, difficulty in leaching the CIGS layer, and difficulty in enriching valuable metals in the recycling process of waste copper indium gallium selenide solar thin-film batteries. The process is green, efficient, simple and suitable for large-scale industrial applications.

[0069] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A green and efficient method for separating waste copper indium gallium selenide solar thin film batteries, characterized in that: The following steps are involved: S1: curling and fixing the waste copper indium gallium selenide solar thin film cells according to a certain curvature, and keeping the curled state for a certain period of time; S2: removing the fixing in step S1 and unfolding the thin film battery; S3: Observe the thin-film battery after being unfolded in step S2, cut the part with gap between the stainless steel substrate and the upper structure into 2×2 cm battery sheets, and repeat steps S1 to S3 for the part without gap; S4: Place the battery cell in a beaker filled with deionized water, place the beaker in an ultrasonic instrument, and ultrasonicate for a certain period of time; S5: placing the battery cell after the ultrasonic treatment in step S4 into an instantaneous pressure difference separator and adding a certain amount of deionized water; S6: Run the instantaneous pressure difference separator. When the temperature and pressure reach certain conditions, open the instantaneous pressure difference separator; S7: collecting the separated products including: CIGS-PET layer, stainless steel substrate, EVA, PET, and performing vacuum drying on the collected products.

2. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 1 is characterized by: The curvature range of the copper indium gallium selenide solar thin film battery curling in step S1 is 4 to 50 μm. -1 , keep the curled state for 30 minutes.

3. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 2 is characterized by: The curvature range is 20 to 50 m -1 .

4. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 1 is characterized by: The part without gaps in step S3 repeats steps S1 to S3, and its curling curvature and curling state retention time remain the same as when step S1 is first performed.

5. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 1 is characterized by: In step S4, the battery cell is ultrasonically treated in deionized water for 10 to 60 minutes.

6. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 5 is characterized by: In step S5, 1-10 ml of deionized water is first added into the instantaneous pressure difference separator, and then the battery cells are placed therein.

7. The green and efficient method for separating waste copper indium gallium selenide solar thin film batteries according to claim 1 is characterized by: In step S6, the pressure range of the instantaneous pressure difference separator is 1-10 MPa, and when the temperature reaches 100-350° C., the instantaneous pressure difference separator is turned on.

8. The green and efficient separation method for copper indium gallium selenide solar thin film cells according to claim 1 is characterized by: In step S7, the vacuum drying temperature is 50° C. and the drying time is 30 min.

9. Application of the method according to any one of claims 1 to 8 in the interlayer separation of copper indium gallium selenide solar thin film cells.

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