Battery assembly and photovoltaic system

Abstract

The present invention 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, a glass plate, and a reflective layer. Each battery string comprises a plurality of cells, each cell comprising a chamfered edge with a chamfer and a straight edge without a chamfer. The chamfered edge and the straight edge of the cell are opposite to each other, and the plurality of cells are arranged sequentially along a first direction. The plurality of battery strings are arranged in parallel, with the cells in adjacent battery strings arranged in opposite directions, and a string spacing is provided between adjacent battery strings. The plurality of battery strings are arranged on one surface of the glass plate, and a reflective layer is provided on the glass plate. The reflective layer comprises a longitudinal film that covers the string spacing, and a widened portion is provided on the longitudinal film to cover the gap between four adjacent cell cells. The longitudinal film covers the string spacing, reflecting light that would otherwise pass directly through the string spacing for use by the cells. The chamfered edge of the cell cell increases the gap between the battery strings, and the widened portion on the longitudinal film can cover the gap between four adjacent cell cells, thereby optimizing light utilization.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic technology, and in particular relates to a battery assembly and a photovoltaic system. Background Art

[0002] As the photovoltaic industry continues to grow, improving the photovoltaic conversion efficiency and enhancing the protection of solar cell modules have become a focus of ongoing attention. Traditional solar cell modules suffer from certain structural design flaws. For one thing, the irrational arrangement of cells within a string can cause significant amounts of light between strings to pass directly through, preventing it from being effectively utilized. This wastes light energy and, in turn, affects the photovoltaic conversion efficiency of the entire module. Furthermore, the lack of effective protection for the gaps between cells makes them susceptible to corrosion from external environmental factors, reducing the lifespan and stability of the module. Summary of the Invention

[0003] Embodiments of the present invention provide a battery assembly and photovoltaic system, aiming to solve the problem that the arrangement pattern of cells in adjacent battery strings may cause a large amount of light between the strings to directly pass through, thereby affecting the photoelectric conversion efficiency of the entire assembly.

[0004] The embodiment of the present invention is implemented as follows: a battery assembly, characterized by comprising: a plurality of battery strings, a glass plate, and a reflective layer;

[0005] Each of the battery strings includes a plurality of battery cells, each of the battery cells includes a chamfered edge with a chamfer and a straight edge without a chamfer, the chamfered edge and the straight edge of the battery cell are opposite to each other, and the plurality of battery cells are arranged in sequence along a first direction, with the chamfered edge of one of two adjacent battery cells facing the straight edge of the other;

[0006] A plurality of battery strings are arranged in parallel, the battery cells in adjacent battery strings are arranged in opposite directions, and there is a string spacing between adjacent battery strings;

[0007] A plurality of battery strings are arranged on one surface of the glass plate, and the reflective layer is arranged between the glass plate and the battery strings. The reflective layer includes a longitudinal film that covers the spacing between the strings, and a widened portion is provided on the longitudinal film. The widened portion completely covers the gaps between four adjacent battery sheets.

[0008] Optionally, there is a gap between adjacent battery cells, the reflective layer includes a transverse film covering the gap, a chamfer is provided at the intersection of the transverse film and the longitudinal film, and four chamfers are connected to form a widened portion.

[0009] Optionally, the arc of the chamfer of the cell is α, the side length of the chamfer of the cell is w, the distance between adjacent cells in a single cell string is d2, the string spacing length is d1, and the area of ​​the widened portion is S, then:

[0010] ;

[0011] in, , 3.2 and 7.5 are empirical coefficients.

[0012] Optionally, the length of d1 is 1.0 mm ≤ d1 ≤ 3.5 mm.

[0013] Optionally, the length of d2 is 0mm≤d2≤1.2mm.

[0014] Optionally, the glass plate is a back plate.

[0015] Optionally, the reflective layer is a reflective glaze.

[0016] Optionally, the reflective layer is arranged on a side of the glass plate close to the battery string.

[0017] Optionally, the widened portion is in the shape of one or more of a circle, a square, and a centrally symmetrical polygon.

[0018] An embodiment of the present invention further provides a photovoltaic system including the above-mentioned battery assembly.

[0019] The beneficial effects achieved by the present invention are realized through a battery assembly comprising several battery strings, a glass plate, and a reflective layer. The battery strings are composed of cells with chamfered and straight edges arranged along a first direction. The cells in adjacent battery strings are arranged in opposite directions and have a spacing between the strings. The glass plate covers the battery strings, and the reflective layer is provided on the glass plate. The longitudinal film covers the spacing between the strings, reflecting light that would otherwise pass directly through the spacing so that it is utilized by the battery cells. Because the chamfered edges of the battery cells increase the gaps between the battery strings, the widened portion of the longitudinal film can completely cover the gaps between four adjacent battery cells, optimizing light utilization while also protecting the gaps between the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a battery assembly provided by an embodiment of the present invention;

[0021] Figure 2 is a schematic structural diagram of a battery cell provided by an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the reflected light path of the reflective layer;

[0023] Figure 4 is a schematic diagram of the gap between battery strings;

[0024] Figure 5 It is a schematic diagram of battery string arrangement;

[0025] Figure 6 This is a schematic diagram of the battery cell layout simulation calculation;

[0026] Figure 7 It is a schematic diagram of the extension line during actual measurement and calculation of the battery cell.

[0027] Description of reference numerals:

[0028] 100, battery assembly; 110, battery string; 111, battery cell; 120, glass plate; 130, reflective layer; 131, longitudinal film; 132, transverse film; 133, widening portion; 140, panel. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical, electrical, or mutually communicative connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0034] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use of other materials.

[0035] The present invention achieves the effects of improving light utilization and protecting the assembly through a battery assembly. The assembly includes several battery strings, glass plates, and a reflective layer. The battery strings are composed of battery cells with chamfered and straight edges arranged along a first direction. The battery cells in adjacent battery strings are arranged in opposite directions and have a spacing between the strings. The glass plates cover the battery strings, and the reflective layer is provided on the glass plates. The longitudinal film covers the string spacing, reflecting light that would otherwise pass directly through the string spacing so that it is utilized by the battery cells. Because the chamfered edges of the battery cells increase the gaps in the battery string, the widened portion of the longitudinal film can completely cover the gaps between four adjacent battery cells, optimizing light utilization and protecting the gaps in the assembly.

[0036] Example 1

[0037] like Figure 1 and Figure 2As shown, this embodiment provides a battery assembly 100, including: a plurality of battery strings 110, a glass plate 120 and a reflective layer 130;

[0038] Each battery string 110 includes a plurality of battery cells 111. Each battery cell 111 includes a chamfered edge and a straight edge without chamfers. The chamfered edge and the straight edge of the battery cell 111 are opposite to each other. The plurality of battery cells 111 are arranged sequentially along a first direction. The chamfered edge of one of two adjacent battery cells 111 is opposite to the straight edge of the other.

[0039] A plurality of battery strings 110 are arranged in parallel, with the battery cells 111 in adjacent battery strings 110 arranged in opposite directions, and a string spacing is provided between adjacent battery strings 110;

[0040] Several battery strings 110 are arranged on one surface of the glass plate 120, and a reflective layer 130 is arranged between the glass plate 120 and the battery strings 110. The reflective layer 130 includes a vertical film 131 that covers the string spacing. A widened portion 133 is provided on the vertical film 131, and the widened portion 133 completely covers the gaps between the four adjacent battery cells 111.

[0041] Each cell 111 includes a chamfered edge and a straight edge without chamfer, and the chamfered edge and the straight edge are opposite to each other, such as Figure 2 The chamfered edge design helps reduce stress concentration at the edge of the cell 111, thereby improving the mechanical stability of the cell 111. Furthermore, the chamfered edge and the straight edge are arranged relative to each other, which facilitates visual identification of the orientation of the cell 111 and facilitates subsequent arrangement and assembly of the cell 111. It is understood that the cell 111 can be stacked or have gaps between them, which is not limited here.

[0042] In each battery string 110, a plurality of battery cells 111 are sequentially arranged along a first direction, and the chamfered edge of one of two adjacent battery cells 111 is opposite to the straight edge of the other, as shown in FIG. Figure 1 As shown, the dotted lines outline the battery cells 111. This arrangement can achieve close contact between the battery cells 111, facilitate the design of the connection lines between the battery cells 111 and the battery side, reduce the space waste inside the battery string 110, and improve the integration of the battery assembly 100.

[0043] It can be understood that the "first direction" is not a universal direction concept with a fixed orientation, but a relative direction introduced to describe the arrangement of battery cells, which is used to clarify the arrangement order of multiple battery cells. It can be imagined that in a plane or space, in order to clearly illustrate how the battery cells are placed in sequence, we call the direction in which they are arranged the "first direction". For example, if multiple battery cells 111 are arranged in sequence along the horizontal direction, the "first direction" is the horizontal direction, and the specific arrangement of the battery cells 111 can be arranged from left to right in the horizontal direction, or from right to left in the horizontal direction. For another example, Figure 1 As shown, if multiple battery cells 111 are arranged in sequence along the vertical direction, the "first direction" is the vertical direction. Specifically, the battery cells 111 can be arranged in sequence from top to bottom along the vertical direction, or from bottom to top along the vertical direction. Of course, if multiple battery cells 111 are arranged in sequence along other directions (such as a 45° oblique line, a 60° oblique line, etc.), the "first direction" is other directions, and this is not limited here.

[0044] Several battery strings 110 are arranged in parallel, with the cells 111 in adjacent battery strings 110 arranged in opposite directions. There is also a string spacing between adjacent battery strings 110. This string spacing can balance the electrical performance of the battery assembly 100, for example, by reducing electromagnetic interference between the battery strings 110, thereby making the overall power generation efficiency of the battery assembly 100 more uniform under sunlight.

[0045] The glass plate 120 covers the battery strings 110 and plays a key role in protecting the battery strings 110. It can prevent external environmental factors such as dust, rain, ultraviolet rays, etc. from damaging the battery strings 110, and provide a relatively stable and safe working environment for the battery strings 110. It is understandable that the glass plate 120 has good light transmittance, which can ensure that sufficient light can pass through and illuminate the battery cells 111, so that the battery cells 111 can effectively perform photoelectric conversion. Under normal circumstances, such as Figure 3 As shown, the battery assembly 100 also includes a panel 140, which is arranged opposite to the glass plate 120, and the battery string 110 and the reflective layer 130 are arranged between the panel 140 and the glass plate 120. The panel 140 and the glass plate 120 jointly provide protection for the battery string 110 and the reflective layer 130.

[0046] The reflective layer 130 generally has excellent reflective properties. By blocking the string spacing and the gaps between the cells 111, the reflective layer 130 reduces light leakage from these areas. When light strikes the reflective layer 130, it is able to reflect the light onto the surface of the cells 111. Light that would otherwise be wasted by passing through the string spacing and the gaps between the cells 111 is redirected onto the cells 111 through the reflection effect of the reflective layer 130, thereby increasing the amount of light received by the cells 111, improving the light utilization efficiency of the entire battery assembly 100, and thus enhancing power generation capacity.

[0047] The reflective layer 130 is arranged between the glass plate 120 and the battery string 110, that is, the glass plate 120 is placed on the outside of the reflective layer 130, and the glass plate 120 forms a protection for the reflective layer 130. The vertical film 131 in the reflective layer 130 is used to cover the string spacing between adjacent battery strings 110. Since the existence of the string spacing may cause some light to pass directly and cannot be used by the battery cells 111, the shielding of the vertical film 131 can make this part of the light be reflected and then used. Due to the presence of the chamfered edges on the battery cells 111, the gap position between the battery strings 110 is increased. The widened portion 133 set on the vertical film 131 can completely cover the gap between the four adjacent battery cells 111, further protecting the gap part of the battery assembly 100 and optimizing light utilization.

[0048] In this embodiment, a battery assembly 100 is used to improve light utilization and protect the assembly. The assembly includes a plurality of battery strings 110, a glass plate 120, and a reflective layer 130. The battery strings 110 are composed of battery cells 111 with chamfered and straight edges arranged along a first direction. The battery cells 111 in adjacent battery strings 110 are arranged in opposite directions and have a spacing between the strings. The glass plate 120 covers the battery strings 110, and the reflective layer 130 is provided on the glass plate 120. The longitudinal film 131 covers the string spacing, reflecting light that would otherwise pass directly through the string spacing and allowing it to be utilized by the battery cells 111. Because the chamfered edges of the battery cells 111 increase the gaps in the battery strings 110, the widened portion 133 on the longitudinal film 131 can completely cover the gaps between four adjacent battery cells 111, optimizing light utilization while protecting the gaps in the assembly.

[0049] Example 2

[0050] In some embodiments, there is a gap between adjacent cells 111 , and the reflective layer 130 includes a transverse film 132 covering the gap. A chamfer is provided at the intersection of the transverse film 132 and the longitudinal film 131 , and four chamfers are connected to form a widened portion 133 .

[0051] Specifically, within a single cell string 110, there is a gap between the adjacent straight edges and chamfered edges of two adjacent cells 111, meaning that the two cells 111 are not stacked. The reflective layer 130 includes a horizontal film 132 and a vertical film 131. The horizontal film 132 is used to cover the gap between adjacent cells 111, while the vertical film 131 is used to cover the gap between adjacent cell strings 110. Typically, the vertical films 131 and 132 are arranged in a grid-like pattern.

[0052] A chamfer is provided at the intersection of the transverse membrane 132 and the longitudinal membrane 131. Specifically, the longitudinal membrane 131 and the transverse membrane 132 each have a certain width and two opposing side edges. The longitudinal membrane 131 has a first transverse side and a second opposing side edge, and the transverse membrane 132 has a first longitudinal side and a second opposing side edge. The four sides have a total of four intersections: the first side edge intersects with the first longitudinal side, the first side edge intersects with the second longitudinal side, the second side edge intersects with the first longitudinal side, and the second side edge intersects with the second longitudinal side. Chamfers are provided at each of the four intersections. The vertices of the four chamfers are connected in sequence to form an octagon, which is the widened portion 133. It is understood that the lengths and curvatures of the four chamfers can be the same or different, and are not limited here.

[0053] In this embodiment, the horizontal films 132 cover the gaps between cells, and the vertical films 131 cover the gaps between strings, reflecting light that would otherwise pass through these gaps back onto the surface of the cell 111. In particular, the widened portion 133 at the intersection more effectively collects and reflects light from all directions, allowing more light to participate in photoelectric conversion, thereby improving the power generation efficiency of the entire cell assembly 100.

[0054] Example 3

[0055] In some embodiments, the arc of the chamfer of the battery cell 111 is α, the side length of the chamfer of the battery cell 111 is w, the distance between adjacent battery cells 111 in a single battery string 110 is d2, the string spacing length is d1, and the area of ​​the widened portion 133 is S, then:

[0056] ;

[0057] in, , 3.2 and 7.5 are empirical coefficients.

[0058] Break down the formula:

[0059]

[0060] =

[0061] in, , calculate and obtain the area of ​​the gap between the four adjacent battery cells covered by the widened portion.

[0062] Specifically, the reflective layer 130 is usually provided on the glass plate 120 in advance, and the arrangement directions of the cells 111 in adjacent cell strings 110 are opposite, such as Figure 4 and 5 As shown, the gap between the first column of cells 111 and the second column of cells 111 has chamfers at the lower left and upper right positions, and the gap between the second column of cells 111 and the third column of cells 111 has chamfers at the upper left and lower right positions. In production, in order to facilitate production and manufacturing, the reflective layer 130 is set to a uniform shape. At the same time, in order to prevent the reflective layer 130 from not completely covering the gap between the cells 111, when calculating the gap between the four adjacent cells 111, it is simulated that the four adjacent cells 111 have chamfers on the four diagonals, as shown in FIG. Figure 6 As shown, the gap between four adjacent battery cells is a diamond shape formed by the four adjacent chamfers extending and connecting, that is, Figure 6 The shaded portion in the image is denoted as ◇ABCD. It can be understood that since the chamfers on each cell 111 are consistent (the arcs of each chamfer are equal and the lengths of each chamfer are equal), and the four chamfers are centrally symmetrical, the enclosed rhombus is a regular rhombus, that is, the four sides of the rhombus are equal and the two diagonals are perpendicular to each other. is the distance between two vertices in the rhombus along the first direction (i.e. Figure 6 The distance between AC), is the distance between two vertices of the rhombus perpendicular to the first direction (i.e. Figure 6 The distance between BD in the figure).

[0063] During the production of modules, unstable cell spacing often occurs, resulting in cells in the same position in different strings not being on the same horizontal line, such as Figure 5 As shown in the figure, due to the instability of the inter-chip spacing, the fluctuation of the inter-chip spacing in actual production causes the actual situation to deviate from the theoretical assumptions, and there will be differences between the results obtained by theoretical calculation and the actual measured data.

[0064] In order to solve the problem of the difference between theoretical calculations and measured data, actual measurements are performed on a large number of battery cells 111 with different inter-cell spacings. The measured data are compared in detail with the theoretically calculated data. Through the comparison, it is possible to clearly see the size and pattern of the deviation between the theoretical value and the actual value under different inter-cell spacings. According to the results of the data comparison, the weight coefficients of each parameter in the calculation formula are adjusted. By adjusting the weight coefficients, the calculation formula can be made closer to the actual situation, thereby improving the accuracy of the theoretical calculation results and making them closer to the measured data. Specifically, if it is found that the measured data shows that the influence of a certain parameter on the battery cell 111 is greater than the influence reflected by the weight of the parameter in the theoretical formula, the weight coefficient of the parameter can be appropriately increased.

[0065] When measuring battery assemblies with different string spacings, since only the chamfered edges exist in the actual battery cell 111, a center line is first drawn at the center of the string spacing, with the center line being equidistant from the battery strings on both sides. Extension lines are then drawn for the chamfers, with the extension lines and the center line forming intersections. The length between the intersections of the two extension lines and the center line is the distance between the two vertices of the gap between the four adjacent battery cells 111 along the first direction, as shown in FIG. Figure 7 As shown in the figure, the distance between A1 and C1 is the measured value. Several measured values ​​are averaged to obtain the average measured value.

[0066]

[0067] Substitute the parameters of cell 111 into the formula without weight coefficient revision for calculation:

[0068]

[0069] There is a large difference between the measured value and the calculated value before the coefficient revision, and the calculated value is smaller than the measured value.

[0070] Combining the measured data with theoretical derivation, the weight coefficients of the parameters in the first direction are revised. Adjust the values ​​of x, y, and z. For example, when x=2, y=1, and z=2, , the parameters of the battery cell 111 are substituted into the formula for calculation. After several experiments, when x=2, y=2, z=1, the parameters of the battery cell 111 are substituted into the formula The calculated value is closest to the measured value.

[0071]

[0072] So the length in this direction is revised to: .

[0073] but:

[0074] S◇ABCD= × ×

[0075] = ×

[0076] That is:

[0077]

[0078] It should be noted that d2 is the distance between adjacent cells 111 in a single battery string 110, with d2 ≥ 0. When cells 111 are stacked, d2 = 0. d1 is the string spacing length, with d1 > 0. α is the radian of the chamfer of the cell 111, with 0 < α < π / 2. Because cell spacing can be unstable, d2 is taken as the design value or the average cell spacing within a single battery string. The coefficients 3.2 and 7.5 are empirical coefficients, verified through several experiments.

[0079] According to the above formula, the specific value of S can be calculated. When S satisfies the above formula, the area of ​​the widened portion 133 can be avoided from being too large or too small. If the area of ​​the widened portion 133 is too large, it will block the light that should be irradiated on the battery cell 111. The amount of light received by the battery cell 111 will be reduced, which will directly lead to a decrease in the efficiency of photoelectric conversion, and thus a decrease in the power generation capacity of the entire battery assembly 100. At the same time, the reflective layer 130 is usually made of materials with specific optical and protective properties, and the cost of these materials is relatively high. When the area of ​​the reflective layer 130 is too large, the amount of material required increases, which directly leads to an increase in the production cost of the battery assembly 100.

[0080] However, the area of ​​the widened portion 133 is too small to completely cover the gaps between the battery cells 111 , which causes some light to pass directly through these gaps and cannot be utilized, resulting in a waste of light energy and reducing the efficiency of the battery assembly 100 in utilizing light.

[0081] In a specific experiment, three solar cells were selected for experimental verification. The radian of the angle between the chamfer of the cell and the straight side is σ, the side length of the chamfer of the cell is w, the distance between adjacent cells in a single cell string is d2, the string spacing length is d1, and the area of ​​the widened portion is S. The specific values ​​are shown in the following table:

[0082]

[0083] In the first group of solar cells, the radian σ of the angle between the chamfer of the cell and the straight side is 0.74, the side length w of the chamfer of the cell is 1.6 mm, the distance d2 between adjacent cells in a single cell string is 0 mm, and the string spacing length d1 is 1.5 mm. Substituting into the above formula, the area S of the widened portion is calculated to have an upper limit of 110.62 mm. 2 (Take the integer value as 110mm 2 ), the lower limit is 47.20mm 2 (The integer value is 47mm 2 ).

[0084] Experimental verification was conducted for different values ​​of the widened portion area S, and the corresponding light leakage defect rate and double-sided rate were tested. The verification results are shown in the following table:

[0085]

[0086] When the area S of the widened portion is lower than the lower limit of the calculation range of 47, there will be a risk of light leakage. When the area S of the widened portion is higher than the upper limit of the calculation range of 110, it will block the light-receiving area on the back of the component and reduce the bifaciality of the component.

[0087] In the second group of solar cells, the radian σ of the angle between the chamfer of the cell and the straight side is 0.74, the side length w of the chamfer of the cell is 1.6 mm, the distance d2 between adjacent cells in a single cell string is 0 mm, the string spacing length d1 is 2.5 mm, and the upper limit of the area S of the widened portion is 205.87 mm 2 (The integer value is 205mm 2 ), the lower limit is 87.84mm 2 (Take the integer value as 87mm 2 ).

[0088] Experimental verification was conducted for different values ​​of the widened portion area S, and the corresponding light leakage defect rate and double-sided rate were tested. The verification results are shown in the following table:

[0089]

[0090] When the area S of the widened portion is lower than the lower limit of the calculation range of 87, there will be a risk of light leakage. When the area S of the widened portion is higher than the upper limit of the calculation range of 205, it will block the light-receiving area on the back of the component and reduce the bifaciality of the component.

[0091] In the third group of solar cells, the radian σ of the angle between the chamfer of the cell and the straight side is 0.74, the side length w of the chamfer of the cell is 1.6 mm, the distance d2 between adjacent cells in a single cell string is 0.5 mm, the string spacing length d1 is 1.5 mm, and the upper limit of the area S of the widened portion is 159.38 mm 2 (The integer value is 159mm 2 ), the lower limit is 68.00mm 2 .

[0092] Experimental verification was conducted for different values ​​of the widened portion area S, and the corresponding light leakage defect rate and double-sided rate were tested. The verification results are shown in the following table:

[0093]

[0094] When the area S of the widened portion is lower than the lower limit of the calculation range of 68, there will be a risk of light leakage. When the area S of the widened portion is higher than the upper limit of the calculation range of 159, it will block the light-receiving area on the back of the component and reduce the bifaciality of the component.

[0095] From the above experimental results, it can be seen that the range of values ​​of the area S of the widened portion is calculated by the formula. When the value of the area S of the widened portion is lower than the lower limit of the calculation range, there will be a risk of light leakage. When the value of the area S of the widened portion is higher than the upper limit of the calculation range, it will block the light-receiving area on the back of the component and reduce the bifaciality of the component.

[0096] In this embodiment, the area S of the widened portion 133 meets the requirements of the formula, ensuring that the widened portion 133 completely covers the gaps between the four battery cells 111 without causing excessive obstruction, thereby ensuring the efficiency of light utilization by the battery assembly 100.

[0097] In some embodiments, the length of d1 is 1.0 mm ≤ d1 ≤ 3.5 mm.

[0098] d1 is the string spacing, the distance between adjacent battery strings 110. Battery strings 110 generate heat during operation. The string spacing facilitates air flow between the battery strings 110, forming a good heat dissipation channel, promptly dissipating heat and reducing the operating temperature of the battery assembly 100. Lower operating temperatures can improve the photovoltaic conversion efficiency of the battery cells 111 and reduce performance degradation caused by high temperatures. Too small a string spacing is detrimental to heat dissipation between battery strings 110.

[0099] At the same time, when the area of ​​the battery assembly 100 is constant, the larger the string spacing, the fewer battery strings 110 can be set, thereby reducing the power generation power per unit area, and further resulting in a decrease in photoelectric conversion efficiency.

[0100] The string spacing is set within the range of 1.0 mm to 3.5 mm, which ensures good heat dissipation of the battery string 110 while ensuring the effective use area of ​​the battery cell 111 and avoiding a reduction in photoelectric conversion efficiency.

[0101] In some embodiments, the length of d2 is 0 mm ≤ d2 ≤ 1.2 mm.

[0102] When the cells 111 in a single battery string 110 are stacked, the distance between adjacent cells 111 is zero. When the cells 111 are not stacked, the distance between adjacent cells 111 is the inter-cell pitch, which is no greater than 1.2 mm. Given a given area of ​​the battery assembly 100, the greater the distance between adjacent cells 111, the smaller the total area occupied by the cells 111, thereby reducing the power generation per unit area and, in turn, the photoelectric conversion efficiency. When the inter-cell pitch is less than or equal to 1.2 mm, the reduction in photoelectric conversion efficiency is avoided.

[0103] Example 4

[0104] In some embodiments, the reflective layer 130 is a reflective frit.

[0105] The reflective glaze has strong scattering and reflection capabilities, and can reflect light incident on the reflective layer 130 back to the surface of the cell 111, increasing the amount of light received by the cell 111 and thereby improving the photoelectric conversion efficiency of the cell assembly 100. Compared to a transmissive film, the reflective glaze can more efficiently utilize light energy and reduce light loss.

[0106] Specifically, the reflective layer 130 may be a titanium dioxide (TiO 2 ) glaze printed on the glass plate 120 .

[0107] Example 5

[0108] In some embodiments, the reflective layer 130 is disposed on a side of the glass plate 120 close to the battery string 110 .

[0109] That is, the reflective layer 130 is disposed on the glass plate 120, and specifically can be disposed on the glass plate 120 by coating, printing, or plating. Placing the reflective layer 130 on the side of the glass plate 120 close to the cell string 110 allows the reflected light to be more directly irradiated onto the cell 111, reducing light loss during propagation. This can more effectively improve the utilization rate of the reflected light by the cell 111, thereby improving power generation efficiency.

[0110] The glass plate 120 can provide physical protection for the reflective layer 130, preventing the reflective layer 130 from being damaged by external scratches, collisions, etc. At the same time, the glass plate 120 can also block the erosion of the reflective layer 130 by ultraviolet rays, water vapor, etc., thereby extending the service life of the reflective layer 130.

[0111] Example 6

[0112] In some embodiments, the glass plate 120 is a backplane.

[0113] The cell 111 is typically encapsulated between two layers of encapsulating film. Above the upper encapsulating film is the front glass of the cell assembly 100, while beneath the lower encapsulating film is a glass plate 120 serving as the backplane. Glass plate 120 is typically made of low-iron tempered glass that has undergone a strengthening treatment. This glass plate offers high mechanical strength and excellent light transmission, effectively protecting the cell 111 from environmental influences. Furthermore, an anti-reflective coating can be applied to the surface of glass plate 120 to further enhance light transmittance.

[0114] Because glass plate 120 has a certain degree of light transmittance, solar cell assembly 100 has the potential for bifacial power generation. Back-incident light can pass through glass plate 120 and illuminate the back of solar cell 111, thus achieving bifacial photovoltaic conversion. Compared to traditional single-sided power generation modules, this can significantly increase power generation revenue.

[0115] Example 7

[0116] In some embodiments, the widened portion 133 is in the shape of a circle, a square, a centrally symmetrical polygon, or several of them.

[0117] A single battery cell 111 includes straight edges and chamfered edges. The battery cells 111 in a single battery string 110 are arranged sequentially along a first direction, and the orientation of the chamfered edges of the battery cells 111 is consistent with the arrangement direction of the battery cells 111. Several battery strings 110 are arranged in parallel, and the arrangement directions of the battery cells 111 in adjacent battery strings 110 are opposite. That is, if the first direction is horizontal, the battery cells 111 in a battery string 110 are arranged horizontally from left to right, and the battery cells 111 in the battery string 110 adjacent to the battery string 110 are arranged horizontally from right to left; if the first direction is vertical, such as Figure 1 As shown, the battery cells 111 in a battery string 110 are arranged from top to bottom in the vertical direction, and the battery cells 111 in the battery string 110 adjacent to the battery string 110 are arranged from bottom to top in the vertical direction.

[0118] The area between the four battery cells 111 in two battery strings 110 is a non-blocking area. Along the arrangement direction of the battery strings 110, the shapes of the two adjacent non-blocking areas are centrally symmetrical. The widening portion 133 is shaped as one or more of a circle, a square, or a centrally symmetrical polygon. The widening portion 133 can completely block both symmetrical non-blocking areas, eliminating the need to adjust the orientation of the widening portion 133 for each non-blocking area, facilitating manufacturing.

[0119] Specifically, the widened portion 133 may be entirely circular, or may be square, or may be partially circular and partially a centrally symmetrical polygon, which is not limited here.

[0120] Example 8

[0121] This embodiment provides a photovoltaic system, including the above-mentioned battery assembly 100.

[0122] Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple battery assemblies 100. For example, multiple battery assemblies 100 can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to be converted into the alternating current required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0123] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery assembly, characterized in that: include: Several cell strings, glass panels, and reflective layers; Each of the battery strings includes a plurality of battery cells, each of the battery cells includes a chamfered edge with a chamfer and a straight edge without a chamfer, the chamfered edge and the straight edge of the battery cell are opposite to each other, and the plurality of battery cells are arranged in sequence along a first direction, with the chamfered edge of one of two adjacent battery cells facing the straight edge of the other; A plurality of battery strings are arranged in parallel, the battery cells in adjacent battery strings are arranged in opposite directions, and there is a string spacing between adjacent battery strings; A plurality of battery strings are arranged on one surface of the glass plate, and the reflective layer is arranged between the glass plate and the battery strings. The reflective layer includes a longitudinal film covering the spacing between the battery strings, and a widened portion is provided on the longitudinal film, and the widened portion covers the gaps between four adjacent battery sheets. The arc of the chamfer of the cell is α, the side length of the chamfer of the cell is w, the distance between adjacent cells in a single cell string is d2, the string spacing length is d1, and the area of ​​the widened portion is S, then: in, , 3.2 and 7.5 are empirical coefficients.

2. The battery assembly according to claim 1, wherein There is a gap between adjacent battery cells. The reflective layer includes a transverse film covering the gap. A chamfer is provided at the intersection of the transverse film and the longitudinal film. Four chamfers are connected to form a widened portion.

3. The battery assembly according to claim 1, wherein: The length of d1 is 1.0mm≤d1≤3.5mm.

4. The battery assembly according to claim 1, wherein The length of d2 is 0mm≤d2≤1.2mm.

5. The battery assembly according to claim 1, wherein: The glass plate is a back plate.

6. The battery assembly according to claim 1 or 5, wherein: The reflective layer is a reflective glaze.

7. The battery assembly according to claim 1 or 5, wherein: The reflective layer is arranged on a side of the glass plate close to the battery string.

8. The battery assembly according to claim 1, wherein: The widened portion is in the shape of a circle, a square, a centrally symmetrical polygon, or several of them.

9. A photovoltaic system, characterized in that: A battery assembly comprising any one of claims 1 to 8.

Images