Backboard glass structure and preparation method thereof, and photovoltaic module and preparation method thereof

Abstract

The invention discloses a backboard glass structure and a preparation method thereof, and a photovoltaic module and a preparation method thereof. The backboard glass structure comprises a backboard glass body and a plurality of bulges, the protrusions are arranged on the side, facing a battery string, of the backboard glass body and located in the string distance, and the height of the protrusions is larger than the thickness of a battery piece when the backboard glass structure is applied. By means of the structure, the problem of subfissure of the battery piece in the lamination process can be effectively avoided on the premise that additional equipment does not need to be additionally arranged or lamination parameters do not need to be adjusted, so that the equipment investment and maintenance cost are reduced, and meanwhile the influence of lamination parameter adjustment on the crosslinking degree, the stripping force and other performance indexes is avoided.

Description

Technical Field

[0001] This invention relates to the field of photovoltaics, and in particular to a backsheet glass structure and its preparation method, and a photovoltaic module and its preparation method. Background Technology

[0002] Among the many performance indicators of photovoltaic (PV) modules, power output undoubtedly occupies a core position, directly reflecting the module's ability to convert solar energy into electrical energy. Microcracks, as a key factor affecting power output, pose a significant threat. Once microcracks appear, the most direct consequence is reduced power output, meaning the module's power generation capacity decreases, failing to achieve the expected power generation effect. Simultaneously, microcracks accelerate the rate of power degradation. Under normal circumstances, the power degradation of PV modules should remain at a relatively stable level, but the presence of microcracks disrupts this balance, causing a rapid decline in module power output in a short period, severely impacting the module's long-term power generation benefits. Even more seriously, microcracks significantly shorten the lifespan of PV modules. As a long-term power generation device, PV modules are typically designed for a lifespan of 25 years or even longer. However, the appearance of microcracks damages the internal structural integrity of the module, making it more susceptible to external environmental factors such as humidity, high temperatures, and mechanical stress, thereby accelerating aging and damage, resulting in an actual lifespan far shorter than the designed lifespan.

[0003] Among various types of microcracks in solar modules, the edges of the solar cells are the most vulnerable. Compared to other parts, the edges of the solar cells face a more complex stress environment during the manufacturing process. During the lamination process, the solar cells need to withstand stresses from high temperatures, high pressures, and the shrinkage of the laminating materials. Because the edges of the solar cells lack sufficient support and cushioning, they are more prone to cracking under the combined effects of these stresses.

[0004] From a microscopic perspective, the crystal structure at the edges of solar cells is more prone to dislocations and slippage under stress, leading to microcracks. Moreover, once microcracks appear at the cell edges, due to their special location, the cracks are more likely to propagate along the edges, further exacerbating the damage to module performance. Therefore, addressing the microcrack problem during the lamination process is of paramount importance, especially for negative-pitch, tandem modules, where the pressure exerted on the cells during lamination after stacking makes them more susceptible to microcracks.

[0005] Currently, the solutions to negative spacing and microcracks in stacked modules are mostly to add a flattening mechanism to reduce the height between the cells, thereby reducing the stress during cell lamination, or to adjust lamination parameters to reduce lamination pressure. However, both of these methods have certain drawbacks:

[0006] The adoption of a flattening mechanism inevitably leads to a significant increase in equipment costs. This includes not only the purchase of new flattening equipment but also the adaptation of existing production lines, all of which undoubtedly increase production costs. Furthermore, as a newly added and complex component, the flattening mechanism requires professional technicians and regular maintenance, further increasing maintenance costs and burdening the company's operations. Additionally, the flattening process is prone to abnormal phenomena such as cell flipping and twisting. Once a cell flips or twists, the risk of microcracks in subsequent lamination processes increases exponentially. This is because the stress distribution during lamination becomes extremely uneven after flipping or twisting, severely damaging the previously relatively stable crystal structure. This makes the cell highly susceptible to cracking under high temperature and pressure, potentially leading to its complete failure.

[0007] When adjusting lamination parameters to prevent microcracks, the lamination process is crucial to the quality of photovoltaic modules. It not only addresses the thorny issue of microcracks but also ensures that other key indicators such as crosslinking degree and peel strength meet standards. Crosslinking degree directly affects the adhesion between the encapsulation material and the solar cells. A suitable degree of crosslinking ensures that the encapsulation material does not age or detach during long-term use, thus maintaining the module's sealing and stability. Peel strength reflects the adhesion between the encapsulation material and the solar cells; sufficient peel strength is essential for ensuring the stability of the module's internal structure. Therefore, adjusting lamination parameters to reduce microcracks often presents a dilemma. For example, reducing lamination pressure to decrease the stress on the solar cells during lamination may lead to insufficient crosslinking of the encapsulation material, reducing the module's weather resistance and reliability. Similarly, lowering lamination temperature or shortening lamination time to reduce thermal stress may affect peel strength, resulting in poor adhesion between the encapsulation material and the solar cells, making delamination more likely during long-term use.

[0008] Therefore, simply adjusting lamination parameters to solve the microcrack problem may lead to unintended consequences and negatively impact other important component quality indicators.

[0009] Therefore, a backsheet glass structure and its preparation method, as well as a photovoltaic module and its preparation method, are proposed here to solve the above problems. Summary of the Invention

[0010] The purpose of this invention is to provide a backsheet glass structure and its preparation method, as well as a photovoltaic module and its preparation method, so as to effectively avoid the problem of microcracks in the cells during the lamination process without adding additional equipment or adjusting lamination parameters, thereby reducing equipment investment and maintenance costs, and avoiding the impact of lamination parameter adjustments on other performance indicators such as crosslinking degree and peel force.

[0011] To solve the above-mentioned technical problems, the present invention provides a back glass structure, including a back glass body and a plurality of protrusions;

[0012] The protrusion is located on the side of the back glass body facing the battery string and is situated in the string spacing. The height of the protrusion is greater than the thickness of the battery cell when the back glass structure is applied.

[0013] Furthermore, the protrusion includes a refractive base layer, a light-transmitting connecting layer, and a support layer arranged sequentially from the direction away from the back glass body.

[0014] Furthermore, the refractive substrate layer is optical glass, and the thickness of the optical glass is 0.3mm-0.4mm.

[0015] Furthermore, the refractive substrate layer contains cerium and / or titanium metal oxides and has a gradient refractive index gradient of 1.52-1.55 in the visible light band, and the surface roughness Ra of the refractive substrate layer is ≤0.5nm.

[0016] Furthermore, the light-transmitting bonding layer is an optical adhesive film with a thickness of 0.2mm-0.3mm.

[0017] Furthermore, the light-transmitting connecting layer comprises 12%-18% by weight of a hybrid material, which is doped with rare earth elements;

[0018] The hybrid material has a molecular chain length of 10nm-20nm, and the rare earth element is lanthanum and / or cerium.

[0019] Furthermore, the light-transmitting connecting layer also contains liquid crystal microdroplets with a volume percentage of 18%-22%, and the liquid crystal microdroplets have a diameter of 2μm-5μm and are dispersed in the light-transmitting connecting layer.

[0020] Furthermore, the support layer includes ultra-clear tempered glass, the surface of which is coated with an anti-reflective film.

[0021] Furthermore, the ultra-white tempered glass has a thickness of 0.3mm-0.4mm, a light transmittance of ≥94%, a Vickers hardness HV≥500, and a reflectance of ≤1%.

[0022] The antireflective film is a nano-silica antireflective film with a thickness of 50nm-80nm.

[0023] Furthermore, the height of the protrusion is 0.8mm-1.1mm, and the length and width are both 0.4mm-0.6mm.

[0024] Furthermore, the protrusion is configured as an optical glass structure.

[0025] In another aspect, the present invention also proposes a method for preparing a backplate glass structure, specifically including the following steps:

[0026] S1. Using a template, high-temperature resistant compatible material is printed onto the side of the backplate glass body facing the battery string and located in the string spacing of the backplate glass body to form a mounting base.

[0027] S2. Sinter the mounting base to soften it;

[0028] S3. Attach the protrusion to the sintered mounting base and cure it.

[0029] Furthermore, the sintering temperature of the mounting base is 600℃-800℃, and the sintering time is 30min-60min.

[0030] On the other hand, the present invention also proposes a method for preparing a photovoltaic module, specifically including the following steps:

[0031] In the above embodiments, the back glass structure has a raised side on which a first adhesive film layer, a battery string, a second adhesive film layer, and a front glass body are sequentially laid to obtain a stacked component;

[0032] The stacked components are laminated to obtain a photovoltaic module.

[0033] In another aspect, the present invention also proposes a photovoltaic module, including the backsheet glass structure described in the above embodiments;

[0034] The photovoltaic module also includes a first encapsulant layer, a battery string, a second encapsulant layer, and a front glass body, which are laid sequentially from bottom to top on the raised side of the back glass structure.

[0035] The protrusion extends into the spacing between the battery strings.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] By setting protrusions on the side of the backplate glass body facing the battery string, and the height of the protrusions being greater than the thickness of the battery cells when the backplate glass structure is used, the pressure can be effectively dispersed during the lamination process of the battery cells, thereby avoiding the problem of microcracks in the battery cells during the lamination process. Correspondingly, compared with the existing technology of adding a flattening mechanism or adjusting lamination parameters, it can effectively reduce equipment investment and maintenance costs, while avoiding the impact of lamination parameter adjustments on other performance indicators such as crosslinking degree and peel force.

[0038] Furthermore, by setting the protrusions to optical glass, the protrusions can disperse lamination pressure while allowing light to pass through with high transmittance, thereby reducing light reflection loss and achieving the purpose of efficient light energy conversion. Thus, it can prevent microcracks in the solar cells while effectively improving the power generation of the photovoltaic module. Attached Figure Description

[0039] Figure 1 This is a top view of the back glass structure in Embodiment 1 of the present invention;

[0040] Figure 2 This is a partial structural diagram of the back glass structure in Embodiment 1 of the present invention;

[0041] Figure 3 This is a flowchart of the method for preparing the backplate glass structure in Embodiment 2 of the present invention;

[0042] Figure 4 This is an exploded view of the structure of the photovoltaic module in Embodiment 4 of the present invention.

[0043] Reference numerals: 1. Back glass body; 2. Protrusion; 21. Refractive base layer; 22. Light-transmitting bonding layer; 23. Support layer; 3. First encapsulant layer; 4. Battery string; 5. Second encapsulant layer; 6. Front glass body. Detailed Implementation

[0044] The backsheet glass structure and its preparation method of the present invention, as well as the photovoltaic module and its preparation method, will be described in more detail below with reference to the schematic diagrams, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the present invention.

[0045] Furthermore, based on the teachings of this specification, those skilled in the art can form new technical solutions through cross-combination of different implementation methods without creating technical contradictions. Such variations should all be considered to fall within the protection scope of this patent.

[0046] The invention is described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0047] Example 1

[0048] like Figure 1 , Figure 2 and Figure 4As shown, an embodiment of the present invention proposes a back glass structure, including a back glass body 1 and a plurality of protrusions 2.

[0049] The protrusion 2 is located on the side of the back glass body 1 facing the battery string 4 and is located in the string spacing to avoid occupying the effective light-receiving area of ​​the battery cell, while not affecting the stacking layout of the existing module lamination process.

[0050] The height of the protrusion 2 is greater than the thickness of the battery cell, so that the protrusion 2 can provide effective support when the battery cell is laminated. That is, the structure prevents the battery cell from cracking due to the extrusion force during the lamination process. Therefore, compared with the existing technology of adding a flattening mechanism or adjusting the lamination parameters, it can effectively reduce equipment investment and maintenance costs, and at the same time avoid the impact of lamination parameter adjustment on other performance indicators such as crosslinking degree and peel force.

[0051] In this embodiment, the protrusion 2 is configured as an optical glass structure. By configuring the protrusion 2 as an optical glass structure, the protrusion 2 can disperse the lamination pressure while allowing light to pass through with high transmittance, thereby reducing light reflection loss and achieving the purpose of efficient light energy conversion. Thus, it realizes the function of preventing microcracks in the battery cell while effectively improving the power generation of the photovoltaic module.

[0052] It should be noted that the protrusion 2 can be set as an integral optical glass structure, or it can be set as an optical glass structure formed by a composite of multiple optical glass layers, in order to further improve the light energy conversion effect.

[0053] In this embodiment, a specific optical glass structure formed by a composite of multiple optical glass layers is proposed to further improve the light transmittance and light energy conversion effect.

[0054] Specifically, the protrusion 2 includes a refractive base layer 21, a light-transmitting connecting layer 22, and a support layer 23 arranged sequentially from the direction away from the back glass body 1.

[0055] The refractive substrate layer 21 is used to reduce light transmission reflection loss and provide support.

[0056] Specifically, the refractive substrate layer 21 is an optical glass containing cerium and titanium metal oxides.

[0057] It should also be noted that the thickness of the optical glass is 0.3mm-0.4mm, and it has a gradient refractive index of 1.52-1.55 in the visible light band, and the surface roughness Ra of the optical glass is ≤0.5nm.

[0058] By employing a gradual refractive index gradient of 1.52-1.55 in the visible light band, the light transmission reflection loss is reduced to below 1%. Furthermore, since the light is incident on the solar cell at a near-vertical angle, the effective power generation time of the photovoltaic module can be effectively extended, thereby increasing the power generation capacity of the photovoltaic module.

[0059] Meanwhile, the optical glass material has excellent robustness, which ensures protection against microcracks in the solar cells.

[0060] The light-transmitting connecting layer 22 is used to connect the refractive substrate layer 21 and the light-transmitting connecting layer 22, and is also used to dynamically adjust the light transmittance to adapt to light transmission under different light intensities.

[0061] Specifically, the light-transmitting bonding layer 22 is an optical adhesive film with a thickness of 0.2mm-0.3mm. In a specific example, the thickness of the optical adhesive film is 0.3mm.

[0062] By limiting the thickness of the optical film, it is possible to both buffer the mechanical stress between the refractive base layer 21 and the support layer 23 during the lamination process (avoiding the breakage of the protrusion 2 due to rigid contact) and avoid light absorption loss due to excessive thickness, so as to balance the stability of the structure and the light transmittance of the film.

[0063] The optical film comprises 12%-18% (preferably 15%) of a hybrid material by mass, and the hybrid material is doped with rare earth elements. Specifically, the rare earth elements are one or more of lanthanum and cerium.

[0064] Because the optical film incorporates 15% rare earth (lanthanum, cerium) hybrid materials by mass, rare earth ions can absorb ultraviolet light and convert it into visible light in low-light environments, thereby extending the effective power generation time of the photovoltaic module and increasing its power output.

[0065] It should also be noted that the molecular chain length of the hybrid material is 10nm-20nm. Since the molecular chain length of the hybrid material is controlled within 10nm-20nm, it can avoid agglomeration through uniform dispersion at the nanoscale. At the same time, it enables the formation of chemical bonds between lanthanum ions or cerium ions and hydroxyl groups on the glass surface (bonding strength ≥5N / mm), ensuring the stability of the connection between the optical adhesive film and the support layer 23 and the refractive substrate layer 21.

[0066] Furthermore, the optical film also contains 18%-22% (preferably 20%) liquid crystal microdroplets by volume, the microdroplets having a diameter of 2μm-5μm and being uniformly dispersed within the optical film. This is particularly beneficial under strong light conditions (light intensity ≥800W / m²). 2The orientation of liquid crystal microdroplet molecules can be adjusted with changes in light intensity, thus dynamically increasing the transmittance of optical films by 10%-15% while reducing light-induced degradation, thereby further improving the power generation of photovoltaic modules.

[0067] The support layer 23 is used to disperse the lamination pressure.

[0068] Specifically, the support layer 23 includes ultra-white tempered glass.

[0069] The ultra-white tempered glass has a thickness of 0.3mm-0.4mm, a light transmittance of ≥94%, a Vickers hardness of HV≥500, and a reflectance of ≤1%, in order to ensure strength while improving light transmittance.

[0070] Furthermore, the surface of the ultra-clear tempered glass is coated with a 50nm-80nm thick nano-silica anti-reflection film. By utilizing the principle of thin-film interference, the surface reflectivity of the ultra-clear tempered glass is reduced from the conventional 4% to below 1%, increasing the visible light transmittance to over 94%. This reduces reflection loss during light transmission. Combined with the gradual refractive index gradient of the refractive substrate layer 21, the overall transmittance of the protrusion 2 can be further improved. Simultaneously, because the nano-scale film is highly compatible with the tempered glass, it avoids affecting the mechanical strength of the ultra-clear tempered glass and is compatible with existing coating processes, requiring no additional modifications to the production line. This reduces light energy loss while ensuring process feasibility and cost control.

[0071] In this embodiment, the height of the protrusion 2 is 0.8mm-1.1mm, and the length and width are both 0.4mm-0.6mm.

[0072] Example 2

[0073] like Figure 3 As shown, this embodiment, based on Embodiment 1, also proposes a method for preparing a backplate glass structure, specifically including the following steps:

[0074] S1. Using a template, high-temperature resistant compatible material is printed onto the side of the back glass body 1 facing the battery string 4, and located in the string spacing of the back glass body 1 to form a mounting base.

[0075] S2. Sinter the mounting base to soften it;

[0076] S3. Attach the protrusion 2 to the sintered mounting base and cure it;

[0077] The sintering temperature of the mounting base is 600℃-800℃, and the sintering time is 30min-60min.

[0078] It should be noted that in step S1, by making a hollow screen printing template that matches the size of multiple protrusions 2, and making the hollow position of the template correspond to the string spacing, the operator can directly attach the template to the side of the back glass body 1 facing the battery string 4 during the screen printing process, and then print the high temperature resistant compatible material onto the back glass body 1 through the screen printing equipment to complete the formation of the mounting base.

[0079] In this embodiment, by using screen printing positioning and sintering fixation, the protrusion 2 and the backsheet glass body 1 are precisely combined without changing the core equipment of the existing production line. This allows for the rapid and convenient fabrication of the backsheet glass structure. Furthermore, since the screen printing method in this fabrication process is compatible with the conventional screen printing process for photovoltaic backsheets, no large-scale modification is required, and mass production is possible, thereby reducing production and maintenance costs.

[0080] Example 3

[0081] This embodiment also proposes a method for preparing photovoltaic modules, which specifically includes the following steps:

[0082] In the back glass structure described in Embodiment 1, a first adhesive film layer 3, a battery string 4, a second adhesive film layer 5, and a front glass body 6 are sequentially laid on one side of the protrusion 2 to obtain a stacked component;

[0083] The stacked components are laminated to obtain a photovoltaic module.

[0084] In this embodiment, by setting a protrusion 2 located at the spacing between the cell strings on the side of the backsheet glass body 1 facing the cell string 4, and utilizing a three-layer structure of support layer 23, cerium titanium oxide-containing refractive substrate layer 21, and rare earth-doped optical film-containing light-transmitting connecting layer 22, pressure is effectively dispersed during lamination, solving the problem of microcracks in the cells caused by stress concentration in traditional negative-spacing modules. At the same time, high light transmittance transmission is achieved through the nano-silica antireflective film on support layer 23 and the gradient refractive index of refractive substrate layer 21, effectively improving the power generation of photovoltaic modules.

[0085] Furthermore, since no additional flattening mechanism or adjustment of lamination parameters is required in the above process, and it is compatible with existing production lines, it can ensure that indicators such as the degree of crosslinking and peel force of the adhesive film meet the standards, thereby reducing equipment investment and maintenance costs.

[0086] Example 4

[0087] This embodiment proposes a photovoltaic module based on Embodiment 3, including the backsheet glass structure described in Embodiment 1.

[0088] Furthermore, the photovoltaic module also includes a first encapsulant layer 3, a battery string 4, a second encapsulant layer 5, and a front glass body 6, which are laid sequentially from bottom to top on the side of the back glass structure with the protrusion 2.

[0089] The protrusion 2 extends into the spacing between the battery strings 4.

[0090] By setting up protrusions 2 including a refractive substrate layer 21, a light-transmitting connecting layer 22, and a support layer 23, and extending the protrusions 2 into the string spacing of the cell string 4, the photovoltaic module can effectively avoid microcracks in the cells during the manufacturing process, and at the same time, it can effectively improve the power generation of the photovoltaic module.

[0091] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A backplate glass structure, characterized in that, Includes the back glass body and multiple protrusions; The protrusion is located on the side of the back glass body facing the battery string and is situated in the string spacing. The height of the protrusion is greater than the thickness of the battery cell when the back glass structure is applied.

2. The back glass structure as described in claim 1, characterized in that, The protrusion includes a refractive base layer, a light-transmitting connecting layer, and a support layer arranged sequentially from the direction away from the back glass body.

3. The back glass structure as described in claim 2, characterized in that, The refractive substrate layer is optical glass, and the thickness of the optical glass is 0.3mm-0.4mm.

4. The back glass structure as described in claim 2 or 3, characterized in that, The refractive substrate contains cerium and / or titanium oxide and has a gradient refractive index of 1.52-1.55 in the visible light band. The surface roughness Ra of the refractive substrate is ≤0.5 nm.

5. The back glass structure as described in claim 2, characterized in that, The light-transmitting bonding layer is an optical adhesive film with a thickness of 0.2mm-0.3mm.

6. The back glass structure as described in claim 2 or 5, characterized in that, The light-transmitting connecting layer contains 12%-18% by weight of a hybrid material, which is doped with rare earth elements; The hybrid material has a molecular chain length of 10nm-20nm, and the rare earth element is lanthanum and / or cerium. Furthermore, the light-transmitting connecting layer also contains liquid crystal microdroplets with a volume percentage of 18%-22%, and the liquid crystal microdroplets have a diameter of 2μm-5μm and are dispersed in the light-transmitting connecting layer.

7. The back glass structure as described in claim 2, characterized in that, The support layer includes ultra-clear tempered glass, the surface of which is coated with an anti-reflective film.

8. The back glass structure as described in claim 7, characterized in that, The ultra-white tempered glass has a thickness of 0.3mm-0.4mm, a light transmittance of ≥94%, a Vickers hardness (HV) of ≥500, and a reflectance of ≤1%. The antireflective film is a nano-silica antireflective film with a thickness of 50nm-80nm.

9. The back glass structure as described in claim 1, characterized in that, The height of the protrusion is 0.8mm-1.1mm, and the length and width are both 0.4mm-0.6mm.

10. The back glass structure as described in claim 1, characterized in that, The protrusion is configured as an optical glass structure.

11. A method for preparing a backplate glass structure, characterized in that, Specifically, the steps include the following: S1. Using a template, high-temperature resistant compatible material is printed onto the side of the backplate glass body facing the battery string and located in the string spacing of the backplate glass body to form a mounting base. S2. Sinter the mounting base to soften it; S3. Attach the protrusion to the sintered mounting base and cure it.

12. The method for preparing the backplate glass structure as described in claim 11, characterized in that, The sintering temperature of the mounting base is 600℃-800℃, and the sintering time is 30min-60min.

13. A method for preparing a photovoltaic module, characterized in that, Specifically, the steps include the following: A first adhesive film layer, a battery string, a second adhesive film layer, and a front glass body are sequentially laid on the side of the back glass structure as described in any one of claims 1-10 to obtain a stacked component; The stacked components are laminated to obtain a photovoltaic module.

14. A photovoltaic module, characterized in that, Includes the back glass structure as described in any one of claims 1-10; The photovoltaic module also includes a first encapsulant layer, a battery string, a second encapsulant layer, and a front glass body, which are laid sequentially from bottom to top on the raised side of the back glass structure. The protrusion extends into the spacing between the battery strings.

Images