Solar cells and photovoltaic modules

Abstract

The utility model provides a cell and a photovoltaic module. The cell includes: four sides, and a first surface and a second surface that are opposite; a passivation layer is respectively arranged on two first sides among the four sides, and the extension direction of the first side is parallel to the extension direction of the first side of the cell; the extension directions of the two first sides are respectively parallel to each other; a fine grid is arranged on at least one of the first surface and the second surface, and the extension direction of the first side is parallel to the extension direction of the fine grid; the structures of the passivation layers respectively arranged on the two first sides are consistent. In the utility model, the passivation layer grows uniformly on the first side of the cell, so as to obtain a passivation layer with a consistent structure on the two first sides, and the passivation layer with a consistent structure has a better passivation effect, improves the performance of the cell, and further reduces the probability of problems such as leakage and short circuit of the cell.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a battery sheet and a photovoltaic assembly. Background Art

[0002] Compared with full-cut cells, half-cut cells have better power output and efficiency. Therefore, half-cut cells are often used to prepare photovoltaic modules.

[0003] Currently, a full cell can be laser or physically cut to obtain half a cell.

[0004] However, due to the cutting damage on the cut side of the half-cell, the passivation effect of the cut side is poor, which in turn affects the power generation efficiency of the cell and increases the risk of leakage. Utility Model Content

[0005] The utility model provides a battery cell and a photovoltaic module to solve the problem in the prior art that a half-cell battery cell has cutting damage on its cut side, resulting in poor passivation effect on the cut side, which in turn affects the power generation efficiency of the battery cell and increases the risk of leakage.

[0006] In order to solve the above problems, the utility model is achieved as follows:

[0007] In a first aspect, an embodiment of the utility model provides a battery cell, comprising:

[0008] four side surfaces, and first and second opposing surfaces;

[0009] A passivation layer is respectively disposed on two first side surfaces among the four side surfaces, and the extension direction of the first side surfaces is parallel to the extension direction of the first side edge of the battery cell; the extension directions of the two first side surfaces are respectively parallel to each other; a fine grid is disposed on at least one of the first surface and the second surface, and the extension direction of the first side edge is parallel to the extension direction of the fine grid;

[0010] The structures of the passivation layers respectively arranged on the two first side surfaces are consistent.

[0011] Optionally, a passivation layer is respectively disposed on two second side surfaces among the four side surfaces except the two first side surfaces; the extension directions of the two second side surfaces are respectively parallel to each other; and the structures of the passivation layers respectively disposed on the two second side surfaces are consistent.

[0012] Optionally, the texture structures of the passivation layers respectively disposed on the two first side surfaces are the same in the extension direction of the first side edges and in the thickness direction of the battery cell;

[0013] The texture structure of the passivation layer disposed on each of the two second side surfaces is the same in the extension direction of the second side edges and in the thickness direction of the battery cell; wherein the extension direction of the second side edges is perpendicular to the extension direction of the first side edges.

[0014] Optionally, the texture structure of the passivation layer includes at least a pyramid-shaped structure, a strip-shaped concave-convex structure, and a pyramid base structure with a quadrilateral top surface.

[0015] Optionally, the passivation layer continuously covers the first side surface along the extension direction of the first side edge, and a ratio between a distance continuously covered by the passivation layer along the extension direction of the first side edge and a length of the first side edge is greater than 95%;

[0016] and / or,

[0017] The passivation layer continuously covers the first side surface along the thickness direction of the battery cell, and the ratio between the distance continuously covered by the passivation layer along the thickness direction of the battery cell and the thickness of the battery cell is between 10% and 100%.

[0018] Optionally, when the passivation layer is a multilayer, at least one passivation layer in the multilayer covers 100% of the first side surface, and other passivation layers in the multilayer except the at least one passivation layer cover 10-90% of the first side surface.

[0019] Optionally, the extension direction of the first surface and the extension direction of the first side surface are chamfered or rounded at the intersection.

[0020] Optionally, the passivation layer includes: one or more layers of an aluminum oxide layer, a silicon nitride layer, a silicon oxide layer, a silicon oxynitride layer, a doped polysilicon layer, an intrinsic amorphous silicon layer, a doped amorphous silicon layer, an intrinsic microcrystalline silicon layer, and a doped microcrystalline silicon layer.

[0021] Optionally, the thickness of the passivation layer at its thickest point is less than 160 nm.

[0022] Optionally, the number of busbars on the cell is greater than or equal to 8, or the cell is a busbar-free cell;

[0023] When the cell is a busbar-free cell, the extension direction of the first side intersects with the extension direction of the second side, or the extension direction of the first side is perpendicular to the extension direction of the second side, and the second side is a side of the cell other than the first side;

[0024] When the battery cell is a battery cell with a main grid, the main grid is arranged perpendicular to the fine grid; and the extension direction of the second side is parallel to the main grid.

[0025] Optionally, a ratio of a length of the second side to a length of the first side is 0.46 to 0.69, and the second side is a side of the battery cell other than the first side.

[0026] In a second aspect, an embodiment of the utility model provides a photovoltaic module, the photovoltaic module comprising: a plurality of battery strings connected in series, the battery string being formed by connecting a plurality of battery cells in series in sequence;

[0027] Two adjacent battery cells in the battery string are connected by a conductive member.

[0028] Optionally, one end of the conductive member is connected to the positive electrode of a battery cell, and the other end of the conductive member is connected to the negative electrode of another adjacent battery cell;

[0029] The conductive member includes any one of a soldering tape, a conductive adhesive, and a metal foil.

[0030] Optionally, the ratio of the number of battery cells included in each battery string to the total number of battery strings is 8 to 15.

[0031] Optionally, the spacing between adjacent battery strings is 0.2 mm to 3 mm;

[0032] The spacing between adjacent battery cells in the battery string is 0.2 mm to 1.2 mm.

[0033] Optionally, the length of the long side of the photovoltaic module is 1722 mm to 2384 mm; the length of the short side of the photovoltaic module is 1130 mm to 1303 mm.

[0034] Optionally, on the first surface and perpendicular to the extension direction of the fine grid of the battery cell, the conductive member passes through the plane where the first side surface of the battery cell is located.

[0035] The passivation layer of the utility model grows uniformly on the first side of the battery cell, thereby obtaining a passivation layer with consistent structure on the two first sides. The passivation layer with consistent structure has a better passivation effect, improves the performance of the battery cell, and further reduces the probability of problems such as battery cell leakage and short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1This is a schematic diagram of the appearance of a battery cell according to an embodiment of the utility model;

[0038] Figure 2 A cross-sectional schematic diagram of a battery cell according to an embodiment of the utility model;

[0039] Figure 3 A partial surface schematic diagram of a battery cell according to an embodiment of the utility model;

[0040] Figure 4 A cross-sectional schematic diagram of another battery cell according to an embodiment of the utility model;

[0041] Figure 5 A cross-sectional schematic diagram of another battery cell according to an embodiment of the utility model;

[0042] Figure 6 It is a partial structural schematic diagram of a battery cell provided in an embodiment of the present application;

[0043] Figure 7 is a surface schematic diagram of a battery cell provided in an embodiment of the present application;

[0044] Figure 8 is a surface schematic diagram of another battery cell provided in an embodiment of the present application;

[0045] Fig. 9 An example diagram of the layout of a photovoltaic module provided in an embodiment of the utility model;

[0046] Fig.10 Another example diagram of the layout of a photovoltaic module provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0047] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can also be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0048] like Figure 1As shown, the utility model provides a battery cell, comprising: four side surfaces, and a first surface and a second surface opposite to each other; a passivation layer is respectively arranged on two first side surfaces 10 of the four side surfaces, and an extension direction x of the first side surface 10 is parallel to an extension direction of a first side edge 11 of the battery cell; the extension directions of the two first side surfaces 10 are respectively parallel to each other; a fine grid 20 is arranged on at least one of the first surface and the second surface, and an extension direction of the first side edge 11 is parallel to an extension direction of the fine grid 20; and the structures of the passivation layers respectively arranged on the two first side surfaces 10 are consistent.

[0049] In the embodiment of the utility model, the cell is used to prepare a photovoltaic module, that is, a plurality of cells are connected in series in sequence to form a cell string, and a plurality of cell strings are electrically connected and arranged in parallel to form a cell array. After the cell array is subjected to processes such as string welding and lamination, a photovoltaic module is formed. Therefore, the cell is an important component unit of the photovoltaic module, and there is a scheme of using a whole cell to construct a photovoltaic module in the related art. Compared with the whole cell of the related art, the cell in the embodiment of the utility model can be a half-cell cell, and the size of the half-cell cell is half of the whole cell. When the format and size of the constructed photovoltaic module are the same, compared with the use of the full-cell cell, the current transmission path of the photovoltaic module obtained by using the half-cell cell is reduced by half or more than half, thereby reducing the internal circuit and internal consumption, and can effectively improve the power generation efficiency of the photovoltaic module. In addition, due to the reduction of internal current and internal loss, the operating temperature of the photovoltaic module and the junction box is reduced, which also reduces the probability of hot spots in the photovoltaic module, and improves the stability and safety of the photovoltaic assembly.

[0050] Specifically, a passivation layer can be provided on the surface of the cell, which is used to reduce the recombination rate on the cell surface and improve the utilization rate of light. In addition, the passivation layer can also resist the erosion of external pollutants, thereby protecting the stability and efficiency of the cell during long-term use.

[0051] In the related art, a half-cell is obtained by cutting a whole cell in half (laser or physical cutting), so that the cut side of the obtained half-cell has a micron-level damaged surface, resulting in different microstructures between the non-cut surface and the cut surface in the half-cell. The thickness of the passivation layer set on the surface of the half-cell is at the nanometer level. This difference in magnitude makes it impossible for the passivation layer to grow uniformly on the damaged surface, resulting in a decrease in the passivation effect. That is, the damaged surface of the half-cell has micron-level uneven burrs. After the photovoltaic module is constructed, the conductive parts used to connect adjacent cells in the photovoltaic module will contact with the burrs, which can easily damage the conductive parts, thereby damaging the circuit of the photovoltaic module, causing a serious decline in the performance of the photovoltaic module and causing the risk of leakage.

[0052] To solve this problem, refer to Figure 1 and Figure 2The half-cell used in the embodiment of the utility model has two opposite first side surfaces 10 and two opposite second side surfaces 12, and the extension direction x of the first side surface 10 is parallel to the extension direction of the first side edge 11 of the cell; at least one of the first surface and the second surface is provided with a fine grid 20, and the first side edge 11 is a side edge whose extension direction is parallel to the fine grid 20. In the embodiment of the utility model, the structures of the passivation layers 30 respectively provided on the two first side surfaces 10 are consistent, and the consistency of structure specifically refers to that the surface texture structure and size (length, width, thickness) of the passivation layers 30 on the two first side surfaces 10 are consistent. Similarly, among the four sides of the cell, the structures of the passivation layers 30 respectively provided on the other two second side surfaces 12 are also consistent. Refer to Figure 1 The extension direction of the first side surface 10 may be consistent with the extension direction of the long side of the battery cell, and the extension direction of the second side surface 12 may be consistent with the extension direction of the short side of the battery cell.

[0053] For example, refer to Figure 3 , which shows the edges of the two first sides of the battery sheet of the embodiment of the utility model (ie Figure 1 Schematic diagram of the morphology of the first side edge 11), it can be seen that there is no cutting damage at the edge of the first side, and the morphology and texture of the edges of different first side edges are consistent.

[0054] It should be noted that the battery cell of the embodiment of the utility model can be a back-contact battery cell, that is, the electrodes and the grid lines are arranged on the back of the battery cell. In addition, the battery cell of the embodiment of the utility model can be a double-sided battery cell, that is, the electrodes and the grid lines are arranged on the first and second surfaces of the battery cell. The embodiment of the utility model does not limit this.

[0055] In the embodiment of the utility model, the first side of the battery cell has no cut damage surface, and the passivation layer can grow uniformly on the first side, so as to obtain a passivation layer with uniform morphology and size, which can bring about a better passivation effect and improve the performance of the battery cell. Specifically, when the passivation layer grows uniformly on the first side of the battery cell without cut damage, the formed passivation layer has a better passivation effect, and in the process of constructing a battery string, adjacent battery cells can be connected in series based on their respective first sides. At this time, the effect of the passivation layer is better, thereby reducing the probability of leakage, short circuit and other problems during series connection, and can further reduce the risk of hidden cracks on the edge of the first side of the battery cell due to stress release during the series connection.

[0056] In summary, in the embodiment of the utility model, the passivation layer grows uniformly on the first side of the battery cell, so as to obtain a passivation layer with consistent structure on the two first sides. The passivation layer with consistent structure has a better passivation effect, improves the performance of the battery cell, and further reduces the probability of problems such as battery cell leakage and short circuit.

[0057] Optional, see Figure 1 Among the four sides, two second sides 12 except the two first sides 10 are respectively provided with a passivation layer; the extension directions of the two second sides 12 are parallel to each other; and the structures of the passivation layers respectively provided on the two second sides 12 are consistent.

[0058] Optional, see Figure 1 The texture structure of the passivation layer provided on each of the two first side surfaces 10 is the same in the extension direction x of the first side edge 11 and in the thickness direction y of the battery cell; the texture structure of the passivation layer provided on each of the two second side surfaces 12 is the same in the extension direction z of the second side edge and in the thickness direction y of the battery cell; wherein the extension direction z of the second side edge is perpendicular to the extension direction x of the first side edge 11.

[0059] In the embodiment of the utility model, since the two first side surfaces 10 of the battery cell have no cutting damage, the passivation layer can grow uniformly on the surface of the first side surface 10, so that the texture structure of the passivation layer set on the two first side surfaces 10 is the same in the direction x and the direction y. The more uniform the growth of the passivation layer on the two first side surfaces 10 is, the more consistent the texture structure is, and the better the passivation effect of the passivation layer can be, thereby improving the performance of the battery cell and further reducing the probability of problems such as leakage and short circuit of the battery cell. Similarly, the passivation layer can also grow uniformly on the surface of the second side surface 12, so that the texture structure of the passivation layer set on the two second side surfaces 12 is the same in the direction z and the direction y, and the passivation effect of the passivation layer is also better, thereby improving the performance of the battery cell.

[0060] Optionally, the texture structure of the passivation layer includes at least a pyramid-shaped structure, a strip-shaped concave-convex structure, and a pyramid base structure with a quadrilateral top surface.

[0061] In an embodiment of the utility model, the texture structure of the passivation layer includes at least a pyramid-shaped structure, a strip-shaped concave-convex structure, and a tower base structure with a quadrilateral top surface, among which the pyramid-shaped structure accounts for a relatively large proportion, and there are more strip-shaped concave-convex structures distributed near the chamfer position of the first side surface, and the strip-shaped concave-convex structure can be formed by a wet method.

[0062] Optional, see Figure 4, which shows a schematic diagram of the cross-sectional structure of the battery cell at viewing angles c and d, wherein viewing angle c is the viewing angle of looking directly at the second side 12, and viewing angle d is the viewing angle of looking directly at the first side 10. Based on viewing angle d, the passivation layer 30 continuously covers the first side 10 along the extension direction x of the first side 11, and the ratio between the distance continuously covered by the passivation layer 30 along the extension direction x of the first side 11 (the length of the shadow area at viewing angle d) and the length of the first side 11 is greater than 95%; and / or, the passivation layer 30 continuously covers the first side 10 along the thickness direction y of the battery cell, and the ratio between the distance continuously covered by the passivation layer 30 along the thickness direction y of the battery cell (the width of the shadow area at viewing angle d) and the thickness of the battery cell is between 10% and 100%.

[0063] In an embodiment of the utility model, when preparing the passivation layer, the passivation layer can be first uniformly grown on the first surface of the battery cell, and then the passivation layer can be further uniformly grown on the side of the battery cell, wherein the passivation layer can be grown partially or completely on the side of the battery cell, and on the basis of the passivation layer being grown entirely on the side of the battery cell, the passivation layer can be further grown on the second surface of the battery cell.

[0064] For example, after the cell has gone through the steps of depositing a doped polysilicon layer and cleaning, one surface of the silicon substrate is covered with a polysilicon layer, and the polysilicon layer can be further plated around the side of the silicon substrate, and then a passivation layer can be covered on the polysilicon layer (the passivation layer can be composed of an aluminum oxide layer and a silicon nitride layer, and the aluminum oxide layer is between the polysilicon layer and the silicon nitride layer). Among them, the polysilicon layer can partially or completely cover the side of the silicon substrate, and similarly, following the coverage of the polysilicon layer on the side of the silicon substrate, the passivation layer can also partially or completely cover the side of the silicon substrate, that is, to ensure that the passivation layer completely covers the polysilicon layer. This is because if the polysilicon layer is not covered by the passivation layer and is directly exposed, the polysilicon layer and the welding ribbon will come into contact when forming a photovoltaic module, resulting in leakage, which affects the quality of the photovoltaic module. In the embodiment of the utility model, since there is no cutting damage on the first side of the battery cell, the uniformity and consistency of the deposition of the passivation layer on the first side are better, which can improve the controllability of the passivation layer to completely cover the polysilicon layer, avoid the situation where the film deposition quality is reduced due to the damaged layer on the surface of the battery cell, enhance the passivation effect of the first side, and reduce the possibility of leakage.

[0065] Reference Figure 4When the passivation layer 30 is grown on the first side 11, the passivation layer 30 can continuously cover the first side 10 along the extension direction x of the first side 11 and the thickness direction y of the cell. The ratio between the distance continuously covered by the passivation layer 30 along the extension direction x of the first side 11 and the length of the first side 11 must be greater than 95%, that is, assuming that the distance continuously covered by the passivation layer 30 along the extension direction x of the first side 11 is h1, and the length of the first side 11 is h2, then h1 / h2>90%. This ensures that the first side 10 is covered by the passivation layer 30 as much as possible in the direction x, so that the passivation layer 30 can cover the connection position of the conductive part when the subsequent cells are connected in series as much as possible, thereby further reducing the risk of hidden cracks at the edge of the first side of the cell due to the stress release of the series connection on the basis of ensuring the passivation effect.

[0066] In addition, the ratio between the distance continuously covered by the passivation layer 30 along the thickness direction y of the battery cell and the thickness of the battery cell is adjustable, and the ratio is in the range of 10% to 100%, that is, assuming that the distance continuously covered by the passivation layer 30 along the thickness direction y of the battery cell is h3, and the thickness of the battery cell is h4, then 10%≤(h3 / h4)≤100%, for example:

[0067] h3 / h4=10%; h3 / h4=20%; h3 / h4=30%; h3 / h4=40%; h3 / h4=50%;

[0068] h3 / h4=60%; h3 / h4=70%; h3 / h4=80%; h3 / h4=90%; h3 / h4=100%. Figure 4 Schematic diagrams of the passivation layer 30 coverage conditions of four cases are respectively given: (h3 / h4) = 25%; (h3 / h4) = 50%; (h3 / h4) = 80%; (h3 / h4) = 100%. The distance that the passivation layer 30 continuously covers the first side surface 10 in the direction y is adjustable, thereby improving the flexibility of the growth range of the passivation layer on the first side surface.

[0069] Optional, see Figure 5 When the passivation layer 30 is a multilayer, at least one passivation layer 30 in the multilayer covers 100% of the surface of the first side surface 10, and other passivation layers 30 in the multilayer except the at least one passivation layer 30 cover 10-90% of the surface of the first side surface 10.

[0070] In the embodiment of the utility model, the passivation layer disposed on the first side surface 10 and / or the second side surface 12 may also be a multi-layer, and at least one passivation layer 30 covers 100% of the plane where it is located, and the remaining passivation layers cover 10-90% of the plane where it is located. The purpose of at least one passivation layer 30 in the multi-layer passivation layer 30 completely covering the plane where it is located is because in some process environments, it is impossible to achieve that each passivation layer completely covers the surface where it is located, so ensuring that at least one passivation layer completely covers the surface where it is located can enhance the passivation effect of the surface.

[0071] Figure 5 For the battery cell in state e, the passivation layer 30 in the multi-layer passivation layer 30 that is in direct contact with the first side 10 covers the first side 10 100%, and the remaining two passivation layers 30 cover 70% and 45% respectively. For the battery cell in state f, the middle passivation layer 30 in the multi-layer passivation layer 30 covers the first side 10 100%, and the remaining two passivation layers 30 cover 70% and 45% respectively. For the battery cell in state g, the passivation layer 30 in the multi-layer passivation layer 30 that is farthest from the first side 10 covers the first side 10 100%, and the remaining two passivation layers 30 cover 70% and 45% respectively. That is, the embodiment of the utility model ensures that at least one passivation layer covers the plane where it is located 100%. Of course, the structure of the multi-layer passivation layer can also be on the second side, and the embodiment of the utility model will not be elaborated on this.

[0072] Optional, see Figure 6 The extending direction of the first surface 50 and the extending direction of the first side surface 10 are chamfered or rounded at the intersection.

[0073] In an embodiment of the utility model, the extension direction of the first surface 50 and the extension direction of the first side surface 10 are chamfered or rounded at the intersection. Compared with the related scheme in which the intersection is a right-angle structure, the structural transition of the scheme in which the intersection is chamfered or rounded in the embodiment of the utility model is smoother, which is beneficial to improving the film uniformity of the passivation layer at the intersection of the extension directions, thereby helping to improve the passivation effect of the passivation layer.

[0074] Optionally, the passivation layer includes: one or more layers of an aluminum oxide layer, a silicon nitride layer, a silicon oxide layer, a silicon oxynitride layer, a doped polysilicon layer, an intrinsic amorphous silicon layer, a doped amorphous silicon layer, an intrinsic microcrystalline silicon layer, and a doped microcrystalline silicon layer.

[0075] In the embodiment of the utility model, any one of the aluminum oxide layer, silicon nitride layer, silicon oxide layer, silicon oxynitride layer, doped polycrystalline silicon layer, intrinsic amorphous silicon layer, doped amorphous silicon layer, intrinsic microcrystalline silicon layer, and doped microcrystalline silicon layer can be used as a passivation layer to achieve a passivation effect. In addition, some of the aluminum oxide layer, silicon nitride layer, silicon oxide layer, silicon oxynitride layer, doped polycrystalline silicon layer, intrinsic amorphous silicon layer, doped amorphous silicon layer, intrinsic microcrystalline silicon layer, and doped microcrystalline silicon layer can also be stacked to obtain a composite passivation layer.

[0076] For example, an aluminum oxide layer and a silicon nitride layer are stacked together to obtain a passivation layer; an intrinsic amorphous silicon layer and a doped amorphous silicon layer are stacked together to obtain a passivation layer; an intrinsic microcrystalline silicon layer and a doped microcrystalline silicon layer are stacked together to obtain a passivation layer. When the passivation layer structure on the first side of the cell includes a stacked aluminum oxide layer and a silicon nitride layer, the thickness of the aluminum oxide layer can be 3 to 20 nm, and the thickness of the silicon nitride layer can be 40 to 140 nm.

[0077] Optionally, the thickness of the passivation layer at its thickest point is less than 160 nm.

[0078] Optionally, the number of busbars on the cell is greater than or equal to 8, or the cell is a busbar-free cell. In the embodiment of the utility model, the cell supports busbar-without busbar forms, thereby increasing the scope of application of the solution.

[0079] Reference Figure 7 When the battery cell is a main grid-free battery cell, the extension direction of the first side 11 intersects with the extension direction of the second side 13, or the extension direction of the first side 11 is perpendicular to the extension direction of the second side 13, and the second side 13 is the side of the battery cell other than the first side 11; the extension direction of the first side 11 is parallel to the extension direction of the fine grid 20.

[0080] Reference Figure 8 When the cell is a cell with a main grid, the main grid 21 is vertically arranged to the fine grid 20 ; the extension direction of the second side 13 is parallel to the main grid 21 .

[0081] In the embodiment of the utility model, the function of the fine grid 20 (also called the collector electrode) is to collect the carriers in the battery cell, and the function of the main grid 21 (also called the collector electrode) is to collect the carriers collected by the fine grid 20. Preferably, the main grid 21 is arranged perpendicular to the fine grid 20, and the extension direction of the first side 11 is perpendicular to the extension direction of the second side 13.

[0082] Optional, see Figure 7 and Figure 8 , a ratio C of a length B of the second side 13 to a length A of the first side 11 is 0.46 to 0.69, and the second side 13 is a side of the battery cell other than the first side 11 .

[0083] In the embodiment of the utility model, based on the size design specification of the half-cell, the ratio C of the length B of the short side (the second side 13) to the length A of the long side (the first side 11) can be set to be in the range of 0.46 to 0.69, that is, the length of the long side is about twice the length of the short side. Compared with the whole cell, the half-cell reduces the current transmission path by half or more, thereby reducing the internal circuit and internal consumption, and can effectively improve the power generation efficiency of the photovoltaic module. Since the half-cell reduces the internal current and internal consumption, the operating temperature of the photovoltaic module and the junction box is reduced, thereby reducing the probability of hot spots in the photovoltaic module and improving the stability and safety of the photovoltaic module.

[0084] Optionally, the ratio C can be any value of 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, and 0.69.

[0085] In a specific example, various corresponding relationships between the length B of the second side 13 and the length A of the first side 11 are listed: when length B = 91.875 mm, length A = 182 mm; when length B = 98 mm, length A = 182 mm; when length B = 93 mm, length A = 175 mm; when length B = 98 mm, length A = 187 mm.

[0086] Reference Fig. 9 , which shows a photovoltaic module, the photovoltaic module 01 includes: a plurality of battery strings 40 connected in series, the battery string 40 is formed by a plurality of battery cells connected in series in sequence; two adjacent battery cells in the battery string 40 are connected by a conductive member 41.

[0087] In the embodiment of the present utility model, refer to Fig. 9 , multiple battery cells are connected in series to form a battery string 40, and further reference is made to Fig.10, multiple battery strings 40 are then electrically connected and arranged to form a battery array. Specifically, adjacent battery strings 40 are electrically connected in series in the extension direction of the fine grid 20 of the battery cell. After the battery array is processed through processes such as string welding and lamination, a photovoltaic module 01 is finally formed. In the process of constructing the battery string 40, the first sides 10 of adjacent battery cells are arranged relative to each other, and the adjacent battery cells are connected in series based on their respective first sides 10 through the conductive member 41. Specifically, one end of the conductive member 41 is connected to the positive electrode on the first side 10 of a battery cell, and the other end of the conductive member 41 is connected to the negative electrode on the first side 10 opposite to another adjacent battery cell. Since the first side 10 of the embodiment of the utility model has no cutting damage, when the passivation layer grows uniformly on the first side 10 without cutting damage in the battery cell, the formed passivation layer has a better passivation effect, and can further reduce the risk of hidden cracks caused by stress release of the edge of the first side 10 of the battery cell connected in series through the conductive member 41.

[0088] Optional, see Fig. 9 One end of the conductive member 41 is connected to the positive electrode of a battery cell, and the other end of the conductive member 41 is connected to the negative electrode of another adjacent battery cell; the conductive member 41 includes any one of a welding strip, a conductive glue, and a metal foil.

[0089] In the embodiment of the utility model, solder strips, conductive adhesives, and metal foils, as elements with good conductive properties and structural strength, can be used as the conductive member 41, and there is no great difficulty in producing and processing the solder strips, conductive adhesives, and metal foils as the conductive member 41.

[0090] For example, when using solder ribbons for interconnection, one end of the solder ribbon may be soldered to the positive electrode of one battery cell, and the other end of the solder ribbon may be soldered to the negative electrode of another battery cell to form a series connection.

[0091] For example, when conductive adhesive is used for interconnection, the adhesive is applied to the positive electrode of one battery cell, and the negative electrode of another battery cell is aligned with the coated area for bonding to form a series connection.

[0092] Optional, see Fig. 9, on the first surface and perpendicular to the extension direction of the fine grid 20 of the battery cell, the conductive member 41 passes through the plane where the first side surface 10 of the battery cell is located. That is, the conductive member 41 of a battery cell passes through the plane where the first side surface 10 of the battery cell is located in a direction perpendicular to the extension direction of the fine grid 20, and is connected to the next adjacent battery cell. In the embodiment of the utility model, the first side surface 10 has a good passivation effect, which can prevent the risk of hidden cracks at the edge of the first side surface 10 of the battery cell due to the stress release of the series connection through the conductive member 41. In addition, the conductive member 41 contacts or overlaps with the edge of the first side surface 10, and the passivation effect of the first side surface 10 is better, which can reduce the risk of leakage, and reduce the probability of burrs or protrusions on the edge of the first side surface 10 damaging the conductive member 41.

[0093] Optionally, a ratio S of the number M of battery cells included in each battery string to the total number N of battery strings is 8 to 15. For example, the ratio S may be any value among 8, 9, 10, 11, 12, 13, 14, and 15.

[0094] For example, the following shows the designs of several different photovoltaic module formats:

[0095] 50-panel, M = 100 cells, N = 10, S = 10; half of the PV module area includes 5 strings of cells, which are connected in series to form a large string group, and then two strings of cells are connected in parallel to form the final PV module;

[0096] 54-panel, M = 108 cells, N = 12, S = 9; half of the PV module area includes 6 strings of cells, which are connected in series to form a large string group, and then two string groups are connected in parallel to form the final PV module;

[0097] 60-panel, M = 120 cells, N = 12, S = 10; half of the PV module area includes 6 strings of cells, which are connected in series to form a large string group, and then two string groups are connected in parallel to form the final PV module;

[0098] 66-panel, M = 132 cells, N = 12, S = 11; half of the photovoltaic module area includes 6 strings of cells, which are connected in series to form a large battery string group, and then two battery strings are connected in parallel to form the largest battery string group.

[0099] Final photovoltaic modules;

[0100] 72-panel, M = 144 cells, N = 12, S = 12; half of the PV module area includes 6 strings of cells, which are connected in series to form a large string group, and then two string groups are connected in parallel to form the final PV module;

[0101] 75 format, M = 150 cells, N = 10, S = 15; half of the area of ​​the PV module includes 5 strings of cells, which are connected in series to form a large string group, and then two strings of cells are connected in parallel to form the final PV module;

[0102] 78 format, M = 156 cells, N = 12, S = 13; half of the area of ​​the photovoltaic module includes 6 battery strings, which are connected in series to form a large battery string group, and then two battery string groups are connected in parallel to form the final photovoltaic module.

[0103] Optional, see Fig. 9 and Fig.10 The spacing m1 between adjacent battery strings 40 is 0.2 mm to 3 mm; the spacing m2 between adjacent battery cells in the battery string 40 is 0.2 mm to 1.2 mm.

[0104] Optional, see Fig. 9 and Fig.10 The length of the long side 011 of the photovoltaic module 01 is 1722 mm to 2384 mm; the length of the short side 012 of the photovoltaic module 01 is 1130 mm to 1303 mm.

[0105] For example, the combination of the lengths of the long side 011 and the short side 012 of the photovoltaic component 01 may include:

[0106] 1722mm×1130mm, 1722mm×1134mm, 1722mm×1136mm;

[0107] 2382mm×1134mm, 2382mm×1132mm, 2382mm×1136mm;

[0108] 2380mm×1134mm, 2380mm×1132mm, 2380mm×1136mm;

[0109] 2384mm×1134mm, 2384mm×1132mm, 2384mm×1136mm.

[0110] In summary, in the embodiment of the utility model, the passivation layer grows uniformly on the first side of the battery cell, so as to obtain a passivation layer with consistent structure on the two first sides. The passivation layer with consistent structure has a better passivation effect, improves the performance of the battery cell, and further reduces the probability of problems such as battery cell leakage and short circuit.

[0111] The terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present utility model can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0112] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A battery cell, characterized in that: The battery cell comprises: four side surfaces, and a first surface and a second surface opposite to each other; A passivation layer is respectively disposed on two first side surfaces among the four side surfaces, and the extension direction of the first side surfaces is parallel to the extension direction of the first side edge of the battery cell; the extension directions of the two first side surfaces are respectively parallel to each other; a fine grid is disposed on at least one of the first surface and the second surface, and the extension direction of the first side edge is parallel to the extension direction of the fine grid; The structures of the passivation layers respectively arranged on the two first side surfaces are consistent.

2. The battery cell according to claim 1, characterized in that: A passivation layer is respectively arranged on two second side surfaces among the four side surfaces except the two first side surfaces; the extension directions of the two second side surfaces are respectively parallel to each other; and the structures of the passivation layers respectively arranged on the two second side surfaces are consistent.

3. The battery cell according to claim 2, characterized in that: The texture structures of the passivation layers respectively disposed on the two first side surfaces are the same in the extension direction of the first side edges and in the thickness direction of the battery cell; The texture structure of the passivation layer disposed on each of the two second side surfaces is the same in the extension direction of the second side edges and in the thickness direction of the battery cell; wherein the extension direction of the second side edges is perpendicular to the extension direction of the first side edges.

4. The battery cell according to claim 3, characterized in that: The texture structure of the passivation layer at least includes a pyramid structure, a strip-shaped concave-convex structure, and a pyramid base structure with a quadrilateral top surface.

5. The battery cell according to claim 1, characterized in that: The passivation layer continuously covers the first side surface along the extension direction of the first side edge, and the ratio between the distance continuously covered by the passivation layer along the extension direction of the first side edge and the length of the first side edge is greater than 95%; and / or, The passivation layer continuously covers the first side surface along the thickness direction of the battery cell, and the ratio between the distance continuously covered by the passivation layer along the thickness direction of the battery cell and the thickness of the battery cell is between 10% and 100%.

6. The battery cell according to claim 1, characterized in that: When the passivation layer is a multilayer, at least one of the multilayer passivation layers covers 100% of the first side surface, and other passivation layers except the at least one passivation layer cover 10-90% of the first side surface.

7. The battery cell according to claim 1, characterized in that: The extending direction of the first surface and the extending direction of the first side face are chamfered or rounded at the intersection.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The passivation layer includes: one or more layers of an aluminum oxide layer, a silicon nitride layer, a silicon oxide layer, a silicon oxynitride layer, a doped polysilicon layer, an intrinsic amorphous silicon layer, a doped amorphous silicon layer, an intrinsic microcrystalline silicon layer, and a doped microcrystalline silicon layer.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The thickness of the passivation layer at its thickest point is less than 160 nm.

10. The battery cell according to claim 1, characterized in that: The ratio of the length of the second side to the length of the first side is 0.46 to 0.69, and the second side is a side of the battery cell except the first side.

11. A photovoltaic module, characterized in that: The photovoltaic module comprises: a plurality of battery strings connected in series, wherein the battery string is formed by connecting a plurality of battery cells according to any one of claims 1 to 10 in series in sequence; Two adjacent battery cells in the battery string are connected by a conductive member.

12. The photovoltaic module according to claim 11, characterized in that: On the first surface and perpendicular to the extension direction of the fine grid of the battery cell, the conductive member passes through the plane where the first side surface of the battery cell is located.

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