Battery assembly and photovoltaic system

Abstract

The utility model is applicable to the field of photovoltaic technology, and provides a battery assembly and a photovoltaic system, the battery assembly comprises a plurality of battery strings arranged at intervals along a first direction and reflective films arranged at intervals of the plurality of battery strings, the reflective films extend along a second direction to cover the intervals, and the reflective films are connected with backlight surfaces of two adjacent battery strings. According to the invention, the reflective films are arranged at the intervals of the battery strings, so that on one hand, the light rays at the intervals of the battery strings are fully reflected, light leakage is prevented, the reflective effect at the intervals is improved, and the intervals of the battery strings are shielded; on the other hand, the distance between the part, located in the interval, of the reflective film and the light-facing surface of the battery string is set to be within 0-150 microns, even if light enters the interval at a small angle, the light can be reflected to the backlight surface of the battery string for utilization, the light energy utilization rate is improved, and the power generation efficiency of the battery assembly is further improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaics, and particularly relates to a battery assembly and a photovoltaic system. BACKGROUND

[0002] A plurality of battery strings are contained in a photovoltaic assembly, and gaps exist between adjacent battery strings. During lamination, a grid is usually arranged on a back glass plate to shield light from the gaps between the battery strings, so as to avoid light leakage and improve light energy utilization. The above-mentioned method mainly plays a role in light shielding, and the utilization rate of light is very low. Therefore, the proportion of light utilization in the gaps between the battery strings is relatively low. CONTENT OF THE UTILITY MODEL

[0003] The application provides a solar cell, and aims to solve the problem that a grid is arranged on a back glass plate to shield light from the gaps between the battery strings, so as to avoid light leakage and improve light energy utilization. The above-mentioned method mainly plays a role in light shielding, and the utilization rate of light is very low. Therefore, the proportion of light utilization in the gaps between the battery strings is relatively low.

[0004] The application is implemented in the following manner. A battery assembly comprises a plurality of battery strings arranged at intervals along a first direction and a light-reflecting film arranged at intervals between the plurality of battery strings. The light-reflecting film extends along a second direction to cover the intervals. An adhesive layer is arranged on the surface of the light-reflecting film facing the battery strings. The light-reflecting film is connected to the back light surfaces of two adjacent battery strings. The distance between the part of the light-reflecting film located in the interval and the light-receiving surface of the battery string is 0-150 microns.

[0005] Optionally, the battery string comprises a plurality of battery pieces, and the plurality of battery pieces are arranged at intervals along the second direction.

[0006] Optionally, the light-reflecting film is provided with a reflective layer on the surface thereof facing the battery strings, and the adhesive layer covers the reflective layer.

[0007] Optionally, the light-reflecting film has a micro-rough structure on the surface thereof facing the battery strings.

[0008] Optionally, the cross-sectional shape of the micro-rough structure comprises one of a triangle, a square or a semicircle.

[0009] Optionally, the light-reflecting film comprises an aluminum film.

[0010] Optionally, the battery assembly further comprises a back adhesive film and a back glass arranged in layers, and the back adhesive film is arranged between the back glass and the light-reflecting film.

[0011] Optionally, the light-reflecting film has a convex structure, the convex structure is arranged to protrude towards the light-receiving surface of the battery string, and the convex structure is arranged in the interval.

[0012] Optionally, the convex structure has a top plane, and the top plane is flush with the light-receiving surface of the battery string.

[0013] Optionally, the width of the light-reflecting film is greater than the width of the interval.

[0014] The application sets the light-reflecting film at the interval of the battery string, on one hand, fully reflects the light at the interval of the battery string, prevents light leakage, improves the light-reflecting effect at the interval, and shields the interval of the battery string, on the other hand, the part of the light-reflecting film located in the interval and the light-receiving surface of the battery string are arranged within 0-150 microns, even if the light enters the interval at a small angle, it can also be reflected to the back surface of the battery string for utilization, improves the light energy utilization rate, and further improves the power generation efficiency of the battery assembly.

[0015] A photovoltaic system comprising the battery assembly described above. The photovoltaic system described in the application has the same technical effects as the battery assembly described above, and will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a first battery assembly provided by the present application;

[0017] Figure 2 is a structural schematic diagram of a second battery assembly provided by the present application;

[0018] Figure 3 is a structural schematic diagram of a light-reflecting film of the battery assembly provided by the present application.

[0019] BRIEF DESCRIPTION OF DRAWINGS

[0020] 100, battery string; 101, battery piece; 200, light-reflecting film; 201, convex structure; 300, adhesive layer; 400, reflecting layer; 500, back adhesive film; 600, back glass; 700, interval. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. The examples of the examples are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The examples described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application. In addition, it should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0022] In the description of the application, it needs to be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0023] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0024] In the description of the application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "above", "over" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0026] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present disclosure, certain examples of components and arrangements are described herein. These are, of course, merely examples and are in no way limiting of the present application. Furthermore, the present application can be implemented in various examples using any number of cardinally and / or referentially designated elements, which are intended to be examples in their own right for the purpose of simplification and clarity. In addition, the present application provides examples of various specific processes and materials, although one of ordinary skill in the art can recognize the application of other processes and / or the use of other materials.

[0027] As shown in Figure 1 A battery assembly includes a plurality of battery strings 100 arranged at intervals along a first direction, and a light-reflecting film 200 arranged at intervals 700 between the plurality of battery strings 100, the light-reflecting film 200 extending along a second direction to cover the intervals 700, the light-reflecting film 200 being provided with an adhesive layer 300 facing the surface of the battery string 100, the light-reflecting film 200 being connected to the back surface of the adjacent two battery strings 100, and the distance between the light-reflecting film 200 and the light-receiving surface of the battery string 100 being 100-150 microns. In the present application, the plurality of battery strings 100 are arranged at intervals 700 along the first direction to form a plurality of intervals 700, and the intervals 700 extend along the second direction, that is, the intervals 700 are formed between the plurality of battery strings 100 two by two, and the light-reflecting film 200 is arranged in each of the plurality of intervals 700. Understandably, the light-reflecting film 200 is also a plurality, and the number of light-reflecting films 200 is the same as the number of intervals 700, achieving one-to-one correspondence between the light-reflecting film 200 and the interval 700. Further, the light-reflecting film 200 is provided with an adhesive layer 300 facing the surface of the battery string 100, and the light-reflecting film 200 is connected to the back surface of the adjacent two battery strings 100 through the adhesive layer 300. In the conventional photovoltaic assembly production process, it may be necessary to additionally paste an EVA film on the back glass to fix the light-reflecting film 200 and the back glass. When in use, a film pasting process needs to be added to the assembly packaging assembly line, and the EVA film of the light-reflecting film is pasted on the back glass at the position corresponding to the above-mentioned gap before lamination by a film pasting device. The process is complicated, and by directly arranging the light-reflecting film 200 and the adhesive layer 300 on the back surface of the battery string 100, the production process can be simplified and the production cost can be reduced. Specifically, the adhesive layer 300 can be made of acrylic adhesive or heat-curable insulating glue. The adhesive layer 300 not only plays a connecting role, but also fixes the battery string 100 during lamination to prevent displacement, which is a multiple use, reduces the operation steps of making photovoltaic assemblies, and saves materials. This fixing effect helps to maintain the structural stability of the photovoltaic assembly and improve the reliability and durability of the photovoltaic assembly.

[0028] Furthermore, the distance between the portion of the reflective film 200 at interval 700 and the light-facing surface of the battery string 100 is 0 to 150 micrometers. Preferably, the distance between the reflective film 200 and the light-facing surface of the battery string 100 is 0 to 120 micrometers. In such an embodiment, the distance between the reflective film 200 and the light-facing surface of the battery string 100 can be any value between 0 micrometers, 50 micrometers, 70 micrometers, 100 micrometers, 105 micrometers, 110 micrometers, 115 micrometers, 120 micrometers, or 0 micrometers to 120 micrometers, and is not specifically limited herein. Within this range, the reflective film 200 can more effectively capture and reflect sunlight to the back surface of the battery string 100, reducing light loss during transmission. Furthermore, when the distance between the portion of the reflective film 200 within the interval and the light-facing surface of the battery string 100 is shortened to between 0 and 120 micrometers, secondary light utilization is increased. The reflective film 200 can effectively reflect secondary light sources such as scattered and reflected light from the ground or surrounding environment to the back surface of the battery string 100, increasing the light-receiving area and light absorption of the battery string 100. By increasing the secondary light utilization of the battery string 100 interval 700, the reflective film 200 can significantly improve the power of the photovoltaic module. Experimental data shows that photovoltaic modules using reflective film can increase power by approximately 10% compared to modules without it. Preferably, the reflective film 200 comprises an aluminum film. Of course, in other embodiments, the reflective film 200 can also be a PET film, PC film, silver-plated composite film, etc., and this application does not limit this.

[0029] In this embodiment, the second direction intersects the first direction. Specifically, the second direction can be perpendicular to the first direction. For example, the first direction can be the length direction of the battery cell 101, and the second direction can be the width direction of the battery cell 101.

[0030] This application provides a reflective film 200 at the intervals 700 of the battery strings 100. On the one hand, it fully reflects the light from the intervals 700 of the battery strings 100, preventing light leakage and improving the reflective effect at the gaps, thus shielding the intervals 700 of the battery strings 100. On the other hand, the distance between the reflective film 200 and the light-facing surface of the battery strings 100 is set within 100-150 micrometers. Even if light enters the intervals 700 at a small angle, it can still be reflected to the back surface of the battery strings 100 for utilization, thereby improving the light energy utilization rate and thus improving the power generation efficiency of the battery module.

[0031] In some embodiments, the battery string 100 includes a plurality of battery pieces 101, and the plurality of battery pieces 101 are partially overlapped along the second direction. The plurality of battery pieces 101 are partially overlapped to form the battery string 100, and the contact area between the overlaps is not electrically connected, i.e., no conductive adhesive or other adhesive is used between the overlap areas, and the battery pieces 101 are only overlapped together. Among them, the overlap area of the adjacent battery pieces 101 in the battery string 100 is provided with a solder strip to fixedly connect the adjacent battery pieces 101. In this way, the battery pieces 101 do not have gaps between them, so that the solder strip can be better hidden, and by overlapping the battery pieces 101, the size of the battery string 100 can be reduced, thereby making the battery string 100 occupy less space. Or, in the case of a certain size of the battery string 100, more battery pieces 101 can be placed, the power of the battery string 100 is improved, and the cost per watt is reduced.

[0032] It can be understood that the partial overlap of the plurality of battery pieces 101 in the battery string 100 means that the adjacent battery pieces 101 in the battery string 100 overlap a part of the area. Among them, the overlap width range can be 0mm to 0.5mm, such as 0mm, 0.1mm, 0.2mm, 0.4mm or 0.5mm, which is not limited in the present application.

[0033] As shown in FIG. 1, Figure 3 In some embodiments, the reflective film 200 is provided with a reflective layer 400 towards the surface of the battery string 100, and the adhesive layer 300 covers the reflective layer 400. The reflective layer 400 is mainly based on the reflection of light. Generally, the reflective layer 400 has a large extinction coefficient. When the light beam is incident on the surface of the reflective layer 400 from the air, the light amplitude entering the reflective layer 400 rapidly attenuates, so that the light energy entering the reflective interior is correspondingly reduced, and the reflected light energy is increased. Exemplarily, the reflective layer 400 can be a silver plating layer or a metal-dielectric reflective layer 400 formed by combining a dielectric layer.

[0034] The reflective film 200 has a micro-textured structure on its surface facing the battery string 100. By setting the micro-textured structure, the specific surface area of ​​the reflective film 200 can be increased, the light-receiving area increased, and the light utilization rate improved. Preferably, the cross-sectional shape of the micro-textured structure includes one of a triangle, a square, or a semicircle. Triangular, square, or semicircular cross-sectional shapes can more effectively capture and reflect sunlight. These shapes can guide light to reflect in multiple directions, increasing the contact opportunity between light and the back surface of the battery string 100, thereby improving the light absorption rate. Especially in the field of solar cells, these shapes can reduce light reflection loss on the back surface of the battery string 100, allowing more light to be absorbed by the battery string 100 and converted into electrical energy. Enhancing light scattering, these cross-sectional shapes can also enhance the scattering effect of light inside the battery string 100. The scattered light can be more evenly distributed inside the battery string 100, improving the photoelectric conversion efficiency.

[0035] The “cross-sectional shape” here refers to the cross-sectional shape after being cut parallel to the thickness direction of the reflective film 200, as is commonly described by those skilled in the art.

[0036] like Figure 2 As shown, the battery assembly also includes a backing film 500 and a back glass 600 stacked together. The backing film 500 is disposed between the back glass 600 and the reflective film 200. During the hot pressing process, the backing film 500 melts, allowing the back glass 600, the backing film 500, and the reflective film 200 to bond tightly together. It is understood that in such an embodiment, the battery assembly may also include a back glass, a backing film, a battery string 100 composed of battery cells 101, a fronting film, and a front glass. Reflective films 200 are disposed at the gaps between the battery strings 100. The film can fill the light-facing and back-facing surfaces of the battery strings 100, as well as between the front glass, the back glass, and adjacent battery cells 101. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the film can be an EVA film or a POE film; the specific choice can be made according to the actual situation and is not limited here. In this way, the reflective film 200 connects the adjacent battery strings 100, shields the interval 700, and reflects the light at the interval 700 to the back surface of the battery strings 100. At the same time, it can also fix the battery strings 100 and prevent them from shifting during the lamination process.

[0037] like Figure 2As shown, in some embodiments, the reflective film 200 has protruding structures 201 arranged towards the light-receiving side of the battery string 100 within the spacing 700. The protruding structures 201 can more effectively capture and reflect light, especially when the light is incident at a specific angle. This design increases the contact area of the light with the surface of the reflective film 200, thereby increasing the intensity and range of the reflected light. The reflected light can be more evenly distributed on the side and light-receiving side of the battery string 100, helping to improve the photoelectric conversion efficiency of the photovoltaic module. The design of the protruding structures 201 can optimize the angle of incidence of light, allowing more light to be incident on the battery string 100 at a closer-to-optimal angle. This helps to reduce the reflection and scattering loss of light within the spacing 700 of the battery string 100, improving the utilization of light. Therefore, the design of the protruding structures 201 can reduce the impact of shadows on the battery string 100, allowing the light within the spacing 700 to be fully reflected onto the battery string 100. Preferably, the protruding structures 201 have a top flat surface that is flush with the light-receiving side of the battery string 100. In photovoltaic modules, shadow effects are an important consideration. The flush top flat surface of the protruding structures 201 and the light-receiving side of the battery string 100 can avoid the light-receiving side of the battery string 100 being covered by shadows, ensuring the output power of the entire photovoltaic module.

[0038] In some embodiments, the width of the reflective film 200 is greater than the width of the spacing 700, and the two ends of the reflective film 200 in the width direction are attached to the edges of the adjacent two battery strings 100. The increase in the width of the reflective film 200 helps to enhance its adhesion to the substrate or mounting surface. A wider film surface can provide a larger contact area, thereby increasing the adhesion and improving the stability and durability of the installation.

[0039] A photovoltaic system comprising the above-mentioned battery module. In this embodiment, the photovoltaic system can be applied in photovoltaic power stations, such as ground power stations, roof power stations, water surface power stations, etc., and can also be applied in devices or apparatuses that utilize solar energy for power generation, such as user solar power sources, solar street lamps, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array can be an array combination of multiple battery modules. For example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to the combiner box, which can combine the currents generated by the photovoltaic arrays. The combined current flows through the inverter to convert it into alternating current required by the power grid, and then is connected to the power grid to realize solar power supply.

[0040] In the description of the application, reference to "some embodiments", "certain embodiments", "exemplary", "specific", or "some examples", etc., indicate that the described features, structures, materials, or characteristics are included in at least one embodiment or example of the application. These embodiments need not necessarily be mutually exclusive; in addition, the specific features, structures, materials, or characteristics in each embodiment can be combined in any suitable manner in other embodiments. Moreover, the specific features, structures, materials, or characteristics can be combined in any suitable manner in other embodiments or examples without departing from the spirit and scope of the application.

[0041] The above description is merely illustrative of the application, and is not to be taken in a limiting sense. Any modification, equivalent replacement, and improvement made within the spirit and principle of the application should be included in the scope of the application.

Claims

1. A battery assembly, comprising: The battery assembly comprises a plurality of battery strings arranged at intervals along a first direction, and a light-reflecting film arranged at the intervals between the battery strings, the light-reflecting film extending along a second direction to cover the intervals, the light-reflecting film being provided with an adhesive layer towards a surface of the battery string, the light-reflecting film being connected to back surfaces of two adjacent battery strings, and a distance between a part of the light-reflecting film located in the interval and a light-receiving surface of the battery string being 0-150 microns.

2. The battery assembly of claim 1, wherein, The battery string comprises a plurality of battery pieces, and the plurality of battery pieces are arranged at intervals along the second direction.

3. The battery assembly of claim 1, wherein, The light-reflecting film is provided with a reflective layer towards the surface of the battery string, and the adhesive layer covers the reflective layer.

4. The battery assembly of claim 1, wherein, The light-reflecting film is provided with a micro-rough structure towards the surface of the battery string.

5. The battery assembly of claim 4, wherein, A cross-sectional shape of the micro-rough structure comprises one of a triangle, a square or a semi-circle.

6. The battery assembly of claim 1, wherein, The light-reflecting film comprises an aluminum film.

7. The battery assembly of claim 1, wherein, The battery assembly further comprises a back adhesive film and a back glass film arranged in layers, the back adhesive film being arranged between the back glass film and the light-reflecting film.

8. The battery assembly of claim 1, wherein, The light-reflecting film has a convex structure, the convex structure being arranged to protrude towards a light-receiving surface of the battery string, and the convex structure being arranged in the interval.

9. The battery assembly of claim 8, wherein, The convex structure has a top plane, and the top plane is flush with the light-receiving surface of the battery string.

10. The battery assembly of claim 1, wherein, A width of the light-reflecting film is greater than a width of the interval.

11. A photovoltaic system characterized by, The battery assembly comprises any one of the battery assemblies according to claims 1-10.

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