Strip-shaped silicon wafer, strip-shaped battery and photovoltaic module

Abstract

The utility model provides a bar-shaped silicon wafer, a bar-shaped battery and a photovoltaic assembly. The strip-shaped silicon wafer is provided with a first side edge and a second side edge which are oppositely arranged in the first direction, the side where the first side edge is located has a first thickness D1, the side where the second side edge is located has a second thickness D2, and the first thickness D1 is larger than the second thickness D2. According to the strip-shaped silicon wafer, through the differentiated thickness arrangement of the silicon substrate, no additional material is added, the phenomenon of strip-shaped battery cracking in the manufacturing process of a photovoltaic module can be effectively improved, the strip-shaped silicon wafer is directly used for manufacturing the strip-shaped battery, the process of cutting the photovoltaic battery is omitted, the production efficiency of the photovoltaic module and the product quality are improved, and the production cost is reduced. Operation is easy, and popularization is convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic technology field especially relates to a strip silicon wafer, strip cell and photovoltaic module. BACKGROUND

[0002] Half piece module technology is to cut the cell piece into at least two half pieces, and then assemble the strip cell into a photovoltaic module, which has many advantages such as reducing packaging loss, improving module reliability, reducing manufacturing cost, meeting the purpose of reducing cost and increasing efficiency, and is an important innovation in the photovoltaic industry in recent years.

[0003] The existing half piece photovoltaic module is usually to cut a conventional photovoltaic cell into two conventional strip cells 1' by laser scribing, and to make the cut conventional strip cell 1' into a half piece photovoltaic module in a series or parallel manner according to the design of the photovoltaic module, as shown in the accompanying drawings. Figure 1

[0004] On this basis, the silicon wafer cannot be further thinned, otherwise in the process of splitting and cell piece series welding, the splitting phenomenon is easy to occur, thereby affecting the production efficiency and quality of the photovoltaic module. Therefore, the cost of the silicon substrate is high.

[0005] Therefore, it is necessary to design a new strip silicon wafer, strip cell and photovoltaic module to solve one of the above problems. UTILITY MODEL CONTENT

[0006] The utility model provides a strip silicon wafer, strip cell and photovoltaic module, by optimizing the thickness of the strip silicon wafer, the strip cell made of the strip silicon wafer of the utility model can obviously improve the splitting of the strip cell without additional materials in the process of the photovoltaic module.

[0007] In order to realize the above purpose, the technical scheme provided by the utility model is as follows:

[0008] A strip silicon wafer has a first side edge and a second side edge oppositely arranged along a first direction, the side where the first side edge is located has a first thickness D1, and the side where the second side edge is located has a second thickness D2, the first thickness D1 is greater than the second thickness D2.

[0009] In an embodiment, the thickness difference between the first thickness D1 and the second thickness D2 is 10-50 microns; and / or, the first thickness D1 is not less than 150 microns and not more than 200 microns.

[0010] In an embodiment, the thickness of the strip silicon wafer gradually decreases from the first side edge to the second side edge.

[0011] ​In an embodiment, the first direction is a direction in which a short side of the strip-shaped silicon wafer extends, and the first side and the second side are both long sides of the strip-shaped silicon wafer.

[0012] In an embodiment, the strip-shaped silicon wafer further comprises a first surface and a second surface, the first surface is perpendicular to a thickness direction of the strip-shaped silicon wafer, and an included angle between the second surface and the first surface is an acute angle, which is not greater than 3°.

[0013] In an embodiment, the first surface is a main light-receiving surface, and the second surface is a secondary light-receiving surface; or, the first surface is a secondary light-receiving surface, and the second surface is a main light-receiving surface.

[0014] A strip-shaped battery comprises a strip-shaped silicon wafer, a first electrode arranged on a first surface of the strip-shaped silicon wafer, and a second electrode arranged on a second surface of the strip-shaped silicon wafer, the first electrode and the second electrode both extend along a first direction, the strip-shaped silicon wafer has a first side and a second side oppositely arranged along the first direction, a first thickness D1 is arranged on a side where the first side is located, and a second thickness D2 is arranged on a side where the second side is located, the first thickness D1 is greater than the second thickness D2.

[0015] In an embodiment, a thickness difference between the first thickness D1 and the second thickness D2 is 10 μm-50 μm; and / or, the first thickness D1 is not less than 150 μm and not greater than 200 μm.

[0016] In an embodiment, the thickness of the strip-shaped silicon wafer gradually decreases from the first side to the second side.

[0017] In an embodiment, the first direction is a direction in which a short side of the strip-shaped silicon wafer extends, and the first side and the second side are both long sides of the strip-shaped silicon wafer.

[0018] In an embodiment, the first surface is perpendicular to a thickness direction of the strip-shaped silicon wafer, and an included angle between the second surface and the first surface is an acute angle.

[0019] In an embodiment, the first surface is a main light-receiving surface, and the second surface is a secondary light-receiving surface; or, the first surface is a secondary light-receiving surface, and the second surface is a main light-receiving surface.

[0020] A photovoltaic module comprises a plurality of the strip-shaped batteries and a solder strip electrically connecting two adjacent strip-shaped batteries, wherein a first side of one strip-shaped battery is arranged adjacent to a second side of another strip-shaped battery.

[0021] In an embodiment, the first surface is perpendicular to a thickness direction of the strip-shaped silicon wafer, and an included angle between the second surface and the first surface is an acute angle, the first surfaces of all the strip-shaped batteries are arranged in parallel, or the first surfaces of all the strip-shaped batteries are located in the same plane.

[0022] Compared with the prior art, the utility model discloses the beneficial effect lies in: the utility model discloses the strip silicon piece is designed as the first side edge thickness is greater than the second side edge thickness, makes the battery piece in the key stress position possess higher mechanical strength to reduce the production process battery piece crack piece, the problem of the occurrence of the fragment, improves the whole yield of assembly and reliability under the premise of not increasing material and process cost.

[0023] Further, through the specific thickness gradient and the angle setting of two surfaces, the stress distribution is effectively improved in the electrode welding and laminating process, the crack rate of brittle thin battery piece is significantly reduced, the mechanical stability of battery piece in the processing and use stage is enhanced under the premise of not increasing additional materials, and the production yield and long-term reliability of photovoltaic module are improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the structure schematic diagram of strip battery connection in prior art photovoltaic module.

[0025] Figure 2 It is the three-dimensional structure schematic diagram of strip silicon piece of the utility model.

[0026] Figure 3 It is Figure 2 the schematic diagram of another angle.

[0027] Figure 4 It is the cutting schematic diagram of cutting to form the strip silicon piece in another embodiment, and the dotted line is the cutting line. Figure 2

[0028] Figure 5 It is the cutting schematic diagram of cutting to form the strip silicon piece in another embodiment, and the dotted line is the cutting line. Figure 2

[0029] Figure 6 It is the structure schematic diagram of strip battery connection in another embodiment of the utility model photovoltaic module.

[0030] Figure 7 It is the structure schematic diagram of strip battery connection in another embodiment of the utility model photovoltaic module.

[0031] Figure 8 It is Figure 7 the schematic diagram of photovoltaic module preparation process.

[0032] 1'-photovoltaic cell, 1-strip silicon piece, 11-first side edge, 12-second side edge, 13-first surface, 14-second surface, 2-strip battery, 21-first electrode, 22-second electrode, 3-photovoltaic module, 31-welding strip. DETAILED DESCRIPTION

[0033] ​​To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0034] In the various illustrations of this utility model, for ease of illustration, some dimensions of the structure or part may be exaggerated relative to other structural parts. Therefore, they are only used to illustrate the basic structure of the subject matter of this utility model.

[0035] The inventors discovered that cracking is easily caused during the manufacturing process of conventional half-cell photovoltaic modules. Please refer to [link / reference needed] for details. Figure 1 As shown, during the series connection of the strip cells 1', the solder strip connects the previous strip cell 1' ( Figure 1 The front electrode of the left-hand strip battery 1' and the rear half of the strip battery 1' Figure 1 The back electrode of the half-cell strip cell 1' on the right side of the middle section. During the lamination process, point A of the latter conventional strip cell 1' is subjected to extrusion by the solder ribbon and indirect extrusion by the laminator, which can easily cause cracking, thus affecting the quality of the conventional half-cell photovoltaic module.

[0036] like Figures 2 to 8 As shown, the present invention aims to provide a strip silicon wafer 110, a strip battery 2100, and a photovoltaic module 31 to solve the problem of wafer cracking.

[0037] Please refer to Figures 2 to 5 As shown, the present invention provides a strip silicon wafer 1, which has a first side 11 and a second side 12 disposed opposite to each other along a first direction, wherein the side where the first side 11 is located has a first thickness D1, and the side where the second side 12 is located has a second thickness D2, wherein the first thickness D1 is greater than the second thickness D2.

[0038] Specifically, such as Figure 2 and Figure 3 As shown, the "strip silicon wafer 1" in this utility model can be understood as a pre-fabricated sheet that is divided into two or more parts compared to a conventional whole silicon wafer. For example... Figure 4 and Figure 5 As shown, this utility model preferably forms half-cell specifications when the silicon rod is cut into silicon wafers, which is beneficial for the direct assembly of the module end into a battery string; and avoids damage to the finished battery cells when they are sliced.

[0039] The first direction is a direction in a silicon wafer extension direction, and the first side edge 11 and the second side edge 12 are two end side edges of the strip-shaped silicon wafer 1 along the first direction. For example, when the strip-shaped silicon wafer 1 is a rectangle, the first side edge 11 and the second side edge 12 can be two long edges or two short edges, respectively.

[0040] The utility model discloses a difference design to the thickness of silicon wafer in the first direction, and the first thickness D1 is designed as greater than the second thickness D2, and the first side edge 11 of silicon wafer can bear higher mechanical stress in the subsequent component manufacturing process, reduces the risk of fragmentation when bearing the external force in the welding band, electrode and laminating process, thereby effectively reducing the probability of the battery piece in the welding, laminating and other links under the traditional thinning trend, significantly improving the technical defects of the traditional thin slice battery piece easy to break.

[0041] Compared with the scheme that the whole silicon wafer is cut in half at the component end in the prior art, the embodiment does not need to increase additional materials and costs, and only by forming different thicknesses at the two side edges of the strip-shaped silicon wafer 1, the mechanical strength and stress resistance of the strip-shaped silicon wafer 1 can be improved, so that the strip-shaped silicon wafer 1 maintains high stability and yield in the processing and use stages, thereby improving the reliability and service life of the final photovoltaic module 3.

[0042] In an embodiment of the utility model, the thickness difference between the first thickness D1 and the second thickness D2 is 10-50 μm. By accurately limiting the thickness difference in the specific range, the first thickness D1 and the second thickness D2 are kept in a suitable range.

[0043] When the thickness difference between D1 and D2 is small, the bearing pressure of the first side edge 11 cannot be significantly improved, and the ideal anti-cracking effect cannot be achieved; when the thickness difference between D1 and D2 is too large, unnecessary material consumption is caused, and the stress on the whole battery piece is uneven due to the too large thickness difference, which may even cause the risk of fragmentation.

[0044] In the range selected in the embodiment, the thickened first side edge 11 can effectively reduce stress concentration when bearing the mechanical stress applied in the production processes such as welding and laminating, and keep the electrical performance and process compatibility of the whole silicon wafer, thereby ensuring that the mechanical strength and yield are significantly improved without increasing the material cost and complicating the process conditions. The range is determined by combining the commonly used silicon wafer thickness and component assembly conditions in actual production, which can ensure that the battery piece still has good toughness and strength under the thinning trend, and improve the yield in the component manufacturing process and the use reliability of the end product.

[0045] In an embodiment of the utility model, first thickness D1 is not less than 150um, not more than 200um. Through setting the lower limit value of first thickness D1, make that strip silicon wafer 1 has enough minimum thickness in the key side edge area, thereby reduce the risk of crack and fragment due to external force in the production process such as welding, laminating and assembly assembly link. Thicker side edge not only improves the mechanical strength and structural stability of silicon wafer in stress concentration position, but also realizes the stability and controllability of assembly process while maintaining reasonable electrical performance and ensuring no additional material increase. Limiting first thickness D1 in the range of not less than 150um is based on the actual manufacturing conditions, silicon wafer toughness and overall design requirements of assembly, which can effectively maintain the quality and reliability of strip silicon wafer 1 under the trend of thinning.

[0046] In an embodiment of the utility model, the thickness of the strip silicon wafer 1 gradually decreases from the first side edge 11 to the second side edge 12. That is, the thickness of the strip silicon wafer 1 at the middle position in the first direction is the third thickness D3, and the thickness difference between the first thickness D1 and the third thickness D3 is consistent with the thickness difference between the second thickness D2 and the third thickness D3.

[0047] By making the silicon wafer form a continuous and smooth thickness transition in the first direction, not only the stress concentration problem caused by sudden thickness change can be effectively avoided, but also the thin sheet part can be more easily laminated and welded in the subsequent steps of assembly manufacturing, thereby reducing the local stress peak and reducing the probability of cracking. At the same time, this gradual design ensures that the thickened side has sufficient strength, thereby improving the mechanical properties of the battery sheet in the thinning trend, improving the yield and service life of the finished product. Compared with the traditional uniform thinning method, the gradual transition structure of the embodiment can achieve better structural strength and reliability without increasing materials and costs, thereby further meeting the requirements of photovoltaic modules 3 for high reliability and high yield.

[0048] In an embodiment of the utility model, the strip silicon wafer 1 is generally rectangular, the first direction is the direction of the short side of the strip silicon wafer 1, and the first side edge 11 and the second side edge 12 are both long sides of the strip silicon wafer 1. Under this definition, the thickness of the silicon wafer gradually changes along the short side direction, thereby making the mechanical stress more reasonably distributed in the key stress area.

[0049] By clearly defining the direction relationship, the positioning accuracy and consistency of the strip silicon wafer 1 can be ensured in the actual production process of assembly, welding, laminating and subsequent processing, thereby further improving the stability and repeatability of the process operation, making the entire assembly manufacturing process more efficient, while ensuring that the thickened side has better mechanical strength in the stress concentration area, thereby effectively reducing the cracking problem and improving the yield and reliability of the entire assembly.

[0050] In an embodiment of the present application, the strip-shaped silicon wafer 1 further comprises a first surface 13 and a second surface 14, wherein the first surface 13 is perpendicular to the thickness direction of the strip-shaped silicon wafer 1, and the second surface 14 forms an acute angle with the first surface 13, and the acute angle is not greater than 3°. During lamination, the first surface 13 remains a horizontal plane, and the second surface 14 is slightly inclined. Through this surface structure design, the battery piece has a clear surface distribution characteristic along the thickness direction, so that more reasonable electrode arrangement and welding positioning of the welding strip 31 can be achieved in the subsequent preparation process of the assembly. If the included angle of the two surfaces is too large, the risk of welding strip sliding off may be caused.

[0051] Since the first surface 13 is perpendicular to the thickness direction, the stress in the thickness direction can be ensured to be more uniform when the electrodes are arranged on the main light-receiving surface (or the secondary light-receiving surface), and the uneven stress concentration of the electrode and the welding strip in the contact area with the silicon wafer is reduced. The design that the second surface 14 forms an acute angle with the first surface 13 can provide a certain buffer space for local displacement and deformation during welding and lamination, thereby further reducing the risk of cracking. Under the premise of not increasing additional materials and maintaining the overall thinning trend, the feature cooperates with the aforementioned gradually changing thickness design, thereby improving the mechanical stability and yield of the entire strip-shaped silicon wafer 1 in the battery piece and assembly processing process, and being beneficial to manufacturing photovoltaic assemblies 3 with higher reliability and longer service life.

[0052] Generally, the main light-receiving surface is the front surface of the battery piece, which receives the direct sunlight; and the secondary light-receiving surface is the back surface, which mainly receives the ambient reflected light and a small amount of light penetrating the battery piece, except for the special time in the morning and evening when it can receive the direct sunlight.

[0053] In an embodiment, the first surface 13 is the main light-receiving surface, and the second surface 14 is the secondary light-receiving surface. The battery piece made of the strip-shaped silicon wafer 1 has the main light-receiving surface of the battery piece kept in a plane during lamination, and the stress is uniform, so that the battery piece is not easy to crack. Moreover, the light-receiving of the main light-receiving surface of the battery piece is uniform and is not affected by the angle.

[0054] In another embodiment, the first surface 13 is the secondary light-receiving surface, and the second surface 14 is the main light-receiving surface. Similar technical effects can also be achieved.

[0055] Please refer to Figures 6 to 8 The present application also provides a strip-shaped battery 2, which comprises a strip-shaped silicon wafer 1, a first electrode 21 arranged on the first surface 13 of the strip-shaped silicon wafer 1, and a second electrode 22 arranged on the second surface 14 of the strip-shaped silicon wafer 1, wherein the first electrode 21 and the second electrode 22 both extend along the first direction.

[0056] The strip-shaped silicon wafer 1 has a thickness difference between the first side 11 and the second side 12 as described above. The use of the strip-shaped silicon wafer 1 with the thickness difference in the first direction in the battery wafer can make the battery better adapt to the changes in mechanical stress during subsequent electrode welding, ribbon 31 installation and assembly lamination, so as to reduce the occurrence of the problems of cracking and fragmentation.

[0057] The specific structure of the strip-shaped silicon wafer 1 is described above and will not be repeated here.

[0058] The first electrode 21 and the second electrode 22 extend along the first direction and are designed in cooperation with the thickness change of the silicon wafer in the first direction to realize reasonable distribution of stress and stress buffering, which not only ensures that the electrical performance of the battery wafer remains stable, but also effectively improves the problem of easy cracking of traditional thin wafer batteries without additional materials and manufacturing costs under mass production conditions, thereby effectively improving the battery yield and long-term reliability of the assembly.

[0059] It should be particularly noted that the strip-shaped battery 2 wafer can be formed by the strip-shaped silicon wafer 1 after the preparation process of the battery, which can avoid damage to the finished battery wafer caused by cutting. Compared with the prior art of cutting the whole battery wafer in half at the assembly end, the present embodiment directly uses a half wafer specification silicon wafer, and the first electrode 21 and the second electrode 22 both extend along the first direction, so that the thickened side can withstand higher stress when welding the electrode and connecting the conductor without being easily broken.

[0060] Of course, the strip-shaped battery 2 wafer can also be cut from a whole battery wafer, which can not only reduce the cracking rate, but also ensure the uniformity of other film layers of the battery and improve the efficiency of the battery.

[0061] Please refer to Figures 7 to 8 As shown in the drawings, the utility model also provides a photovoltaic module 3, including a plurality of aforementioned strip-shaped batteries 2, the welding band 31 of electrically connecting adjacent two strip-shaped batteries 2, wherein the first side 11 of one strip-shaped battery 2 and the second side 12 of another strip-shaped battery 2 are adjacent.

[0062] By orderly arranging and adjacent setting a plurality of strip-shaped batteries 2, each strip-shaped battery 2 can form a reasonable layout of electrical series and parallel connection at the level of the photovoltaic module 3. In this layout, as shown in the drawings, Figure 7As shown, the laminated module is located above the module in the figure, applying downward pressure to compress the module. The thickness variation design of the strip cell 2 itself effectively alleviates the stress concentration area A during the assembly process. The module can better maintain the structural integrity of the cells during lamination, welding, and subsequent encapsulation, significantly reducing the occurrence of cell cracking and breakage. At point B, because there is no solder strip compression, even if the thickness is reduced, cell cracking will not occur. Adjacent strip cells 2 are electrically connected by solder strips 31, and due to the aforementioned reinforced structural characteristics of the strip cells 2, this connection is more stable and reliable without adding extra materials. Compared to traditional modules that require segmenting the entire cell at the end of the module, the pre-placed strip cell 2 scheme and the gradient thickness structure adopted in this embodiment can complete the module assembly with higher yield and stability, thereby effectively improving the overall quality and service life of the module.

[0063] In one embodiment of this utility model, the first surface 13 is perpendicular to the thickness direction of the strip silicon wafer 1, the second surface 14 and the first surface 13 form an acute angle, the first surfaces 13 of all the strip batteries 2 are arranged in parallel, or the first surfaces 13 of all the strip batteries 2 are located in the same plane.

[0064] By maintaining consistency and uniformity of the first surface 13 of all strip cells 2 at the component level, lamination (at...) Figure 7 In processes such as top-down pressure application and welding, the stress on each cell is more uniform, avoiding localized stress concentration caused by surface tilt or unevenness, thereby further reducing the occurrence rate of cell cracking in thin-film batteries during this process.

[0065] Each strip-shaped cell 2 has a gradient thickness and sharp-angled surface design according to the aforementioned embodiment, resulting in a more optimized overall module in terms of mechanical stress distribution and electrical performance. Module production can achieve significant yield improvement and enhanced reliability without additional material and cost inputs. Compared to the dilemma of traditional modules that cannot balance thinness and mechanical strength, this embodiment, while achieving uniform surface characteristics, better coordinates the structural relationship between the cells and the module, enabling the module to have better crack resistance, stability, and durability during long-term use.

[0066] In practical applications, silicon ingots can be processed into standard cross-sectional shapes using conventional wire cutting processes, and then precision cutting techniques can be used to form a gradually thickening structure where the first side 11 and the second side 12 are distributed along the short side direction, such as... Figure 4 and Figure 5In an embodiment, the thickness D1 of the first side edge 11 is about 170 μm, and the thickness D2 of the second side edge 12 is about 130 μm. By controlling the cutting conditions and the grinding process, the thickness difference is strictly controlled between 20 μm and 40 μm. The obtained strip-shaped silicon wafer 1 has higher mechanical toughness at the first side edge 11 with larger thickness, which is beneficial to bear greater stress when the electrode ribbon is overlapped, and reduces the micro-cracks generated at A during the lamination and series connection process of the production line.

[0067] When the strip-shaped silicon wafer 1 is processed into strip-shaped batteries 2 through the battery manufacturing processes such as diffusion, plating, electrode screen printing, sintering, etc., each battery can be directly spliced without additional cutting during the stringing process, and meanwhile, the strip-shaped batteries 2 have higher stability during the welding process of the conductive member connecting adjacent batteries. When the final assembly is laminated and formed, the first surfaces 13 of the strip-shaped batteries 2 are flush, the assembly as a whole bears uniform stress, and without additional materials or processes, higher yield and mechanical reliability can be obtained, and the cracking and power attenuation caused by external environmental stress can be reduced during long-term operation in the field. Therefore, the embodiment proves that the strip-shaped silicon wafer 1 with thickness difference in the short edge direction can significantly improve the mechanical strength and service life of the assembly, and provides an effective solution for large-scale and low-cost production.

[0068] It should be understood that although the present specification is described in terms of embodiments, each embodiment does not necessarily contain only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be combined to form other embodiments that can be understood by those skilled in the art.

[0069] The above series of detailed descriptions are only specific descriptions of the feasible embodiments of the present application, and are not intended to limit the protection scope of the present application. Any equivalent embodiments or modifications made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A bar-shaped silicon wafer having a first side edge and a second side edge oppositely arranged along a first direction, characterized in that, The first side has a first thickness D1, and the second side has a second thickness D2, wherein the first thickness D1 is greater than the second thickness D2.

2. The bar-shaped silicon piece according to claim 1, wherein The thickness difference between the first thickness D1 and the second thickness D2 is 10-50 μm. The first thickness D1 is not less than 150 μm and not more than 200 μm.

3. The bar-shaped silicon piece according to claim 1, wherein The thickness of the strip-shaped silicon wafer gradually decreases from the first side to the second side.

4. The bar-shaped silicon piece according to claim 1, wherein The first direction is the direction in which the short side of the strip-shaped silicon wafer extends, and the first side and the second side are both long sides of the strip-shaped silicon wafer.

5. The bar-shaped silicon piece according to any one of claims 1 to 4, wherein The first surface is perpendicular to the thickness direction of the strip-shaped silicon wafer, and the second surface forms an acute angle with the first surface, and the acute angle is not greater than 3°.

6. The bar-shaped silicon piece according to claim 5, wherein The first surface is a main light-receiving surface, and the second surface is a secondary light-receiving surface. Alternatively, the first surface is a secondary light-receiving surface, and the second surface is a main light-receiving surface.

7. A strip-shaped battery comprising a strip-shaped silicon sheet, a first electrode provided on a first surface of the strip-shaped silicon sheet, and a second electrode provided on a second surface of the strip-shaped silicon sheet, the first electrode and the second electrode each extending in a first direction, characterized in that, The strip-shaped silicon wafer has a first side and a second side oppositely arranged along a first direction, the first side has a first thickness D1, and the second side has a second thickness D2, wherein the first thickness D1 is greater than the second thickness D2.

8. The bar battery of claim 7, wherein the battery housing includes a first housing portion and a second housing portion, the first housing portion and the second housing portion being separable from one another. The thickness difference between the first thickness D1 and the second thickness D2 is 10-50 μm. The first thickness D1 is not less than 150 μm.

9. The bar battery of claim 7, wherein the battery housing includes a first housing portion and a second housing portion, the first housing portion and the second housing portion being separable from one another. The thickness of the strip-shaped silicon wafer gradually decreases from the first side to the second side.

10. The bar battery of claim 7, wherein the battery housing includes a first housing portion and a second housing portion, the first housing portion and the second housing portion being separable from one another. The first direction is the direction in which the short side of the strip-shaped silicon wafer extends, and the first side and the second side are both long sides of the strip-shaped silicon wafer.

11. The bar battery of any of claims 7-10, wherein, The first surface is perpendicular to the thickness direction of the strip-shaped silicon wafer, and the second surface forms an acute angle with the first surface, and the acute angle is not greater than 3°.

12. The bar battery of claim 11, wherein, The first surface is a main light-receiving surface, and the second surface is a secondary light-receiving surface. Alternatively, the first surface is a secondary light-receiving surface, and the second surface is a main light-receiving surface.

13. A photovoltaic module, characterized by The photovoltaic module comprises a plurality of strip-shaped cells according to any one of claims 7-12, and a solder strip electrically connecting two adjacent strip-shaped cells, wherein the first side of one strip-shaped cell is arranged adjacent to the second side of another strip-shaped cell.

14. The photovoltaic module of claim 13, wherein, The first surface is perpendicular to the thickness direction of the strip-shaped silicon wafer, and the second surface forms an acute angle with the first surface, and the first surfaces of all strip-shaped cells are parallelly arranged or located in the same plane.

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