A method and system for edge isolation of thin film batteries

Abstract

The application provides a thin-film battery edge cleaning insulation method, which comprises the following steps: after the electrode of a thin-film battery piece is prepared, a scribing step is added before edge cleaning insulation is performed by using a first laser; the scribing step is specifically as follows: scribing is performed at the junction of the edge cleaning insulation area and the effective area of the battery, so as to form an isolation belt between the edge cleaning insulation area and the effective area of the battery, and the depth of the isolation belt is consistent with the depth of the edge cleaning insulation; the edge cleaning insulation is specifically as follows: the first laser is used to scan the edge cleaning insulation area, so that the heat affected zone of the spot of the first laser overlaps with all or part of the isolation belt without exceeding the isolation belt. By the method of forming the isolation belt through scribing before the traditional laser edge cleaning insulation step, the problems of serious surface protrusion and surface electrode peeling caused by laser edge cleaning are reduced or solved, the conversion efficiency and stability of the battery are improved, and the appearance of the battery is optimized.

Description

Technical Field

[0001] This invention belongs to the field of perovskite battery processing, and particularly relates to a method and system for cleaning and insulating thin-film batteries. Background Technology

[0002] Perovskite, named after the Russian mineralogist Lev Perovski, is a material with the same crystal structure as the mineral perovskite oxide (the earliest discovered perovskite crystal, CaTiO3). Perovskite solar cells are solar cells that utilize perovskite-type organometal halide semiconductors as light-absorbing materials. They belong to the third generation of solar cells and are also known as new-concept solar cells. The theoretical conversion efficiency limit of crystalline silicon solar cells is 29.4%. Currently, the highest reported laboratory conversion efficiency of crystalline silicon solar cells has reached 26.6%. As the conversion efficiency of crystalline silicon solar cells approaches its limit, perovskite solar cells are emerging. Since perovskite solar cell technology was listed as a strong contender for the Nobel Prize in Chemistry in 2017, the market has gradually recognized its commercial value. In the past two years, the development of perovskite solar cell technology has accelerated, and some companies have achieved small-scale mass production. With continuously breaking conversion efficiency records, perovskite solar cells have become globally recognized as the most promising next-generation photovoltaic material. However, the commercialization of perovskite cells faces the challenge of maintaining high conversion efficiency and high stability even in large-area fabrication. Solving this problem requires continuous improvement and optimization of the large-area fabrication process for perovskite solar cells.

[0003] Perovskite solar cells can be broadly classified into two categories: nip (upright) and pin (inverted) structures, both with simple structures. Taking an inverted planar perovskite solar cell as an example, from bottom to top, the structure consists of: glass, transparent electrode (TCO), electron transport layer, perovskite layer, hole transport layer, and metal electrode. Perovskite solar cells boast high photoelectric conversion efficiency, simple fabrication process, and low production and material costs. The core photoelectric conversion materials are inexpensive and solution-preparable, facilitating fabrication using roll-to-roll technology that does not require vacuum conditions, making them easier to produce than traditional silicon solar cells.

[0004] Large-area fabrication of perovskite solar cells also requires laser scribing processes, similar to those used in cadmium telluride, copper indium gallium selenide, and amorphous silicon thin-film solar modules, to achieve series-parallel connections and edge cleaning insulation between perovskite cells. Current edge cleaning insulation technology for perovskite solar cells uses infrared lasers for direct edge cleaning and insulation, such as... Figures 1 to 3As shown, due to the presence of a laser heat-affected zone 3 around the laser spot 2, severe protrusions and electrode peeling occur on the battery edge surface next to the laser scanning area 4 due to heat. This results in laser-induced heat-affected zone 1-1 and protrusions 1-2 caused by the edge film layer, affecting the appearance, electrical performance, and stability of the battery cell 1. The protruding and peeled electrodes affect the conductivity of the electrodes and reduce the effective area of ​​the battery, thus significantly reducing the battery's conversion efficiency. Furthermore, the protruding and peeled electrodes are also an unstable factor. In subsequent processing, if the protruding electrodes detach and fall to other locations on the battery, it can cause leakage, and in severe cases, even destroy the entire battery. Summary of the Invention

[0005] The main objective of this invention is to provide a method and system for cleaning and insulating thin-film batteries, thereby reducing the problems of severe surface protrusions and surface electrode peeling caused by laser cleaning.

[0006] The technical solution adopted in this invention is: a method for cleaning and insulating the edges of a thin-film battery. This method adds a scribing step after the electrodes of the thin-film battery are prepared and before the edge cleaning and insulation is performed using a first laser. The specific marking step is as follows: at the junction of the area to be cleaned and the effective area of ​​the battery, a line is drawn to form an isolation zone between the area to be cleaned and the effective area of ​​the battery. The depth of the isolation zone is the same as the depth of the cleaning and insulation. The edge cleaning insulation specifically involves: using a first laser to scan the area to be cleaned and insulated. When the spot of the first laser scans close to the isolation strip, the spot of the first laser is at least tangent to the edge of the isolation strip or partially located within the isolation strip, such that the heat-affected zone of the first laser spot overlaps with all or part of the isolation strip but does not exceed the isolation strip.

[0007] The marking step described above is performed using a metal needle.

[0008] According to the above method, the line drawing step is completed using a second laser, and the spot size of the second laser is 10-100μm.

[0009] According to the above method, the second laser is an infrared, ultraviolet, or green laser with a pulse width of picosecond, femtosecond, or nanosecond.

[0010] According to the above method, the laser wavelength of the second laser is 532nm, the pulse width is 20ps, and the spot size is 15μm.

[0011] A method for preparing a solar cell module, the method comprising the aforementioned thin-film battery edge cleaning and insulation method.

[0012] The preparation method described above is used to prepare perovskite solar cell modules, and specifically includes the following steps: S1. Select a transparent glass substrate, and clean and dry it; S2. Prepare a conductive thin film on a transparent glass substrate; S3. Scribing lines on the conductive film; S4. Sequentially prepare the electron transport layer, perovskite layer and hole transport layer; S5. Draw lines on the functional layer composed of the hole transport layer, perovskite layer and electron transport layer. S6. Prepare the electrode; S7. At the junction of the insulation area to be cleaned and the effective area of ​​the battery, a line is drawn to cut the electrode, hole transport layer, perovskite layer, electron transport layer and conductive film to form an isolation zone between the insulation area to be cleaned and the effective area of ​​the battery. S8. Use the first laser to repeatedly scan the insulation area to be cleaned. During the first scan, the heat-affected zone of the first laser spot only overlaps with all or part of the isolation strip. S9. Electrode wiring and encapsulation complete the fabrication of the perovskite solar cell module.

[0013] A thin-film battery edge cleaning and insulation system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the thin-film battery edge cleaning and insulation method.

[0014] The beneficial effects of this invention are: by forming an isolation strip by scribing before the traditional laser edge cleaning insulation step, the problem of severe surface protrusion and surface electrode peeling caused by laser edge cleaning is reduced or solved, thereby improving the conversion efficiency and stability of the battery and optimizing its appearance. Attached Figure Description The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a schematic diagram of the battery cell structure before and after edge insulation cleaning.

[0015] Figure 2 This is a schematic diagram of the edge-cleaning step in the prior art.

[0016] Figure 3 A top view diagram of the solar cell during edge insulation cleaning (corresponding to) Figure 2 first step).

[0017] Figure 4 This is a schematic diagram of the scribing step according to an embodiment of the present invention.

[0018] Figure 5 for Figure 4A top-down view.

[0019] Figure 6 This is a schematic diagram of the edge-cleaning step according to an embodiment of the present invention.

[0020] Figure 7 for Figure 4 Detailed illustration.

[0021] In the figure: 1-Battery cell, 1-1-Protrusion caused by laser thermal effect, 1-2-Protrusion brought up by edge film layer, 2-Laser spot, 3-Laser thermal affected area, 4-Laser scanning area, 5-Isolation zone, 6-Edge cleaning area, 11-Transparent glass substrate, 12-Conductive thin film, 13-Electron transport layer, 14-Perovskite layer, 15-Hole transport layer, 16-Electrode. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] This invention provides a method for edge cleaning and insulation of thin-film batteries. This method adds a scribing step after the electrodes of the thin-film battery are prepared and before edge cleaning and insulation is performed using a first laser. like Figure 4 and Figure 5 As shown, the specific marking step is as follows: at the junction of the area to be cleaned and insulated and the effective area of ​​the battery cell 1, a line is drawn to form an isolation strip 5 between the area to be cleaned and insulated and the effective area of ​​the battery. The depth of the isolation strip 5 is consistent with the depth of the cleaning and insulation. like Figure 6 As shown, the edge cleaning insulation specifically involves: using a first laser to scan the area to be cleaned and insulated. When the laser spot 2 of the first laser approaches the isolation strip for scanning, the laser spot 2 of the first laser is at least tangent to the edge of the isolation strip 5 or partially located within the isolation strip 5, so that the laser heat-affected zone 3 of the laser spot 2 of the first laser overlaps with all or part of the isolation strip 5, but does not exceed the isolation strip 5, thus not affecting the effective area.

[0024] Generally, edge insulation clearing utilizes a first laser to scan the area of ​​insulation to be cleared. The first scan begins close to the effective area, and then the scan proceeds sequentially away from the effective area until the entire edge insulation area is scanned. See also... Figure 5In the first scan, the laser spot 2 of the first laser is tangent to the edge of the isolation zone 5, or partially located within the isolation zone 5. Furthermore, the heat-affected zone 3 of the laser spot 2 overlaps entirely or partially with the isolation zone 5, but does not extend beyond the isolation zone 5, thus not affecting the effective area. Alternatively, when the first laser scans the area to be cleared, it can start scanning from a distance away from the effective area until it reaches a point close to the effective area. The aforementioned requirements must also be met during the final scan near the effective area.

[0025] More specifically, the scribing step can be performed using a metal needle. Alternatively, a second laser can be used, with a spot size of 10-100 μm. Here, spot size refers to the diameter when the spot is circular and the side length or width when the spot is square.

[0026] Specifically, the second laser is an infrared, ultraviolet, or green laser with a pulse width of picosecond, femtosecond, or nanosecond.

[0027] More preferably, the second laser has a wavelength of 532 nm, a pulse width of 20 ps, ​​and a circular spot with a diameter of 15 μm. The circular spot can also be replaced by a spot of other shapes.

[0028] When a second laser is used to complete the line drawing step, the laser wavelength of the second laser is 532 ns, the pulse width is 20 ps, ​​and the spot is a circular spot with a diameter of 15 μm. The circular spot can also be replaced by a spot of other shapes.

[0029] The first laser is preferably an infrared laser, with a circular spot having a diameter of 10-100 μm or more. Preferably, the spot size of the first laser is not smaller than that of the second laser, and the laser wavelength is 1064 nm. The circular spot can also be replaced by a spot of other shapes.

[0030] A method for fabricating a perovskite solar cell module using the aforementioned thin-film battery edge cleaning and insulation method, the method comprising the following steps: Figure 7As shown, S1. Select a transparent glass substrate 11 and clean and dry it; S2. Prepare a conductive thin film 12 on the transparent glass substrate; S3. Scribe the conductive thin film; S4. Sequentially prepare an electron transport layer 13, a perovskite layer 14, and a hole transport layer 15; S5. Scribe the functional layer composed of the hole transport layer 15, the perovskite layer 14, and the electron transport layer 13; S6. Prepare an electrode 16; S7. Scribe the boundary between the area requiring edge cleaning and the effective area of ​​the battery, and cut the electrode 16, the hole transport layer 15, the perovskite layer 14, the electron transport layer 13, and the conductive thin film 12. S8. Using a first laser, the insulating area to be cleaned is scanned sequentially. During the first scan (when the laser spot 2 of the first laser is close to the insulating strip), the laser spot 2 of the first laser is at least tangent to the edge of the insulating strip 5 or partially located within the insulating strip 5, so that the laser heat-affected zone 3 of the laser spot 2 of the first laser overlaps with all or part of the insulating strip 5, but does not exceed the insulating strip 5, thus not affecting the effective area; S9. Electrode wiring and encapsulation are performed to complete the fabrication of the perovskite solar cell module.

[0031] The main improvements of this invention are S7 and S8. For the fabrication of other similar solar cell modules, the existing insulation cleaning method can be replaced with the S7 and S8 methods of this invention.

[0032] The present invention also provides a thin-film battery edge cleaning and insulation system. The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the thin-film battery edge cleaning and insulation method.

[0033] The following two specific examples further illustrate the present invention.

[0034] Example 1: (1) Select a transparent glass substrate and clean and dry it; (2) A conductive thin film TCO was prepared on a cleaned glass substrate by magnetron sputtering. The thickness of the conductive thin film TCO was 500 nm. (3) Use an infrared laser to scribing the conductive thin film TCO. The laser wavelength is 1064nm, the pulse width is 200ns, and the spot size is 20μm. (4) An electron transport layer is prepared by magnetron sputtering or vapor deposition. The electron transport layer material is TiO2 and the thickness is 50 nm. (5) Use inkjet or spin coating to form a perovskite layer. The perovskite layer material is FAPbI3 and the thickness is 500 nm. (6) A hole transport layer is prepared by magnetron sputtering or vapor deposition. The hole transport layer material is spiro-OMeTAD and the thickness is 50 nm. (7) Use a green laser to scribing lines on the functional layers (hole transport layer + perovskite layer + electron transport layer), with a laser wavelength of 532nm and a pulse width of 20ns; (8) Electrodes are prepared by magnetron sputtering or vapor deposition, and the material is gold or TCO; (9) At the junction of the area requiring edge cleaning insulation and the effective area of ​​the battery, use a metal needle to scribing. The metal needle is 15μm and the scribing width is 15μm. Cut the electrode + hole transport layer + perovskite layer + electron transport layer + conductive thin film TCO as an isolation strip. (10) Use a large spot infrared laser for edge cleaning and insulation. The spot size is 400 μm circle, the laser wavelength is 1064 nm, and the heat-affected zone is about 10 μm. (11) Electrode wiring and encapsulation to complete the fabrication of perovskite solar cell modules.

[0035] Example 2: (1) Select a transparent glass substrate and clean and dry it; (2) A conductive thin film TCO was prepared on a cleaned glass substrate by magnetron sputtering. The thickness of the conductive thin film TCO was 600 nm. (3) Use an infrared laser to scribing the conductive thin film TCO. The laser wavelength is 1064nm, the pulse width is 100ns, and the spot size is 30μm. (4) A hole transport layer was prepared by magnetron sputtering or vapor deposition. The hole transport layer material was spiro-OMeTAD and the thickness was 60 nm. (5) Use inkjet or spin coating to form a perovskite layer. The perovskite layer material is FAPbI3 and the thickness is 550 nm. (6) An electron transport layer is prepared by magnetron sputtering or vapor deposition. The electron transport layer material is TiO2 and the thickness is 60 nm. (7) Use a green laser to scribing lines on the functional layers (hole transport layer + perovskite layer + electron transport layer), with a laser wavelength of 532nm and a pulse width of 10ns; (8) Electrodes are prepared by magnetron sputtering or vapor deposition, and the material is gold or TCO; (9) At the junction of the area requiring edge cleaning insulation and the effective area of ​​the battery, a small spot laser is used to scribing the line, cutting the electrode + hole transport layer + perovskite layer + electron transport layer + TCO as an isolation zone. The laser wavelength is 532nm, the pulse width is 20ps, and the spot size is 15μm circle. (10) Use a large spot infrared laser for edge cleaning and insulation. The spot size is 400 μm circle, the laser wavelength is 1064 nm, and the heat-affected zone is about 10 μm. (11) Electrode wiring and encapsulation to complete the fabrication of perovskite solar cell modules.

[0036] In this invention, at the boundary between the area requiring edge cleaning and insulation and the effective area of ​​the battery, a small-spot laser (second laser) is used to scribing or mechanically scribing is performed to cut through the electrode + hole transport layer + perovskite layer + electron transport layer + conductive thin film TCO, forming an insulating strip. Then, a large-spot laser (first laser) is used for laser edge cleaning and insulation. The heat-affected zone of the large-spot laser near the effective area of ​​the battery is not irradiated on the perovskite film layer, so there will be no protrusion. The protrusion on the other side will be removed after the large-spot scan of the next line. Therefore, the area and degree of protrusion are greatly reduced.

[0037] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for cleaning the insulation edges of a thin-film battery, characterized in that, This method adds a scribing step after the electrodes of the thin-film solar cell are prepared and before the first laser is used for edge cleaning and insulation. The specific scribing step is as follows: at the junction of the area to be cleaned and the effective area of ​​the battery, a second laser is used to scribing to form an isolation zone between the area to be cleaned and the effective area of ​​the battery. The depth of the isolation zone is consistent with the depth of the cleaning and insulation. The spot size of the second laser is 10-100μm. The edge cleaning insulation specifically involves: using a first laser to scan the area to be cleaned and insulated. When the spot of the first laser scans close to the isolation strip, the spot of the first laser is at least tangent to the edge of the isolation strip or partially located within the isolation strip, such that the heat-affected zone of the first laser spot overlaps with all or part of the isolation strip but does not exceed the isolation strip.

2. A method for cleaning and insulating the edges of a thin-film battery, characterized in that, This method adds a scribing step after the electrodes of the thin-film solar cell are prepared and before the first laser is used for edge cleaning and insulation. The specific marking step is as follows: at the junction of the area to be cleaned and the effective area of ​​the battery, a metal needle is used to mark a line to form an isolation zone between the area to be cleaned and the effective area of ​​the battery. The depth of the isolation zone is the same as the depth of the cleaning insulation. The edge cleaning insulation specifically involves: using a first laser to scan the area to be cleaned and insulated. When the spot of the first laser scans close to the isolation strip, the spot of the first laser is at least tangent to the edge of the isolation strip or partially located within the isolation strip, such that the heat-affected zone of the first laser spot overlaps with all or part of the isolation strip but does not exceed the isolation strip.

3. The thin-film battery edge cleaning and insulation method according to claim 1, characterized in that, The second laser is an infrared, ultraviolet, or green laser with a pulse width of picosecond, femtosecond, or nanosecond.

4. The thin-film battery edge cleaning and insulation method according to claim 3, characterized in that, The second laser has a wavelength of 532nm, a pulse width of 20ps, and a spot size of 15μm.

5. The thin-film battery edge cleaning and insulation method according to claim 1 or 2, characterized in that, The first laser is an infrared laser with a spot size of 10-100μm or larger.

6. A method for preparing a solar cell module, characterized in that, This preparation method includes the thin-film battery edge cleaning and insulation method according to any one of claims 1 to 5.

7. The preparation method according to claim 6, characterized in that, This preparation method is used to prepare perovskite solar cell modules, and specifically includes the following steps: S1. Select a transparent glass substrate, and clean and dry it; S2. Prepare a conductive thin film on a transparent glass substrate; S3. Scribing lines on the conductive film; S4. Sequentially prepare the electron transport layer, perovskite layer and hole transport layer; S5. Draw lines on the functional layer composed of the hole transport layer, perovskite layer and electron transport layer. S6. Prepare the electrode; S7. At the junction of the insulation area to be cleaned and the effective area of ​​the battery, a line is drawn to cut the electrode, hole transport layer, perovskite layer, electron transport layer and conductive film to form an isolation zone between the insulation area to be cleaned and the effective area of ​​the battery. S8. Use the first laser to repeatedly scan the insulation area to be cleaned. During the first scan, the heat-affected zone of the first laser spot only overlaps with all or part of the isolation strip. S9. Electrode wiring and encapsulation complete the fabrication of the perovskite solar cell module.

8. A thin-film battery edge cleaning and insulation system, characterized in that, The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the thin-film battery edge cleaning and insulation method according to any one of claims 1 to 5.

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