Battery piece and photovoltaic module

Abstract

The invention discloses a battery piece and a photovoltaic module, and belongs to the technical field of battery pieces. Comprising a substrate and fine grid lines, and the multiple fine grid lines are arranged on the substrate in an array mode; each fine grid line comprises a base body layer and a reflecting layer, and the reflecting layer at least covers part of the base body layer. In the embodiment of the invention, the light reflecting layer is arranged, so that short-wavelength light is directly reflected to the substrate through the reflecting layer, the light is indirectly reflected to the back glass through the reflecting layer and then is irradiated to the substrate, and the two parts act differently and jointly. According to the embodiment of the invention, the back power of the photovoltaic module is improved by improving the light reflection utilization of the back of the battery piece, so that the back overall power and the double-sided rate of the photovoltaic module are improved.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic module technology, specifically relating to a solar cell and a photovoltaic module. Background Technology

[0002] The photovoltaic industry is currently facing a situation where product prices continue to decline and new technologies are developing rapidly.

[0003] With continuous breakthroughs and implementation of base metallization technology, it has become an effective means to reduce component costs and increase profit margins. Currently, the main method of base metallization is to use base metal materials such as copper to replace expensive silver paste.

[0004] However, base metal copper absorbs more short-wavelength light, causing some wavelengths of light incident on the copper grid lines to be unusable by the battery. This results in reduced battery power and decreased module bifaciality in practical applications. Summary of the Invention

[0005] The purpose of this application is to provide a solar cell and a photovoltaic module that can solve at least the problems of reduced solar cell power and decreased bifaciality.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application provide a battery cell, including a substrate and fine grid lines, wherein a plurality of the fine grid lines are arranged in an array on the substrate; the fine grid lines include a substrate layer and a reflective layer, wherein the reflective layer at least covers a portion of the substrate layer; the material of the substrate layer includes a base metal.

[0007] In the embodiments of this application, multiple fine grid lines are arranged in an array on the substrate. When the substrate serves as the supporting foundation for the fine grid lines, its flatness and stability directly affect the consistency of the fine grid line array. If the substrate surface is flat, it provides a structural prerequisite for the efficient operation of the subsequent reflective layer.

[0008] Furthermore, the substrate layer uses base metals, such as copper, iron, aluminum, and nickel, which are cheaper than precious metals or their alloys, with copper being preferred. Base metals possess sufficient mechanical strength and conductivity to support the long-term adhesion of the reflective layer, preventing the reflective layer from detaching and causing reflection failure. They also meet the basic conductivity requirements for collecting photogenerated carriers in the fine grid lines, without substantially affecting the charge transfer efficiency on the solar cell. Base metals themselves have a certain absorption capacity for short-wavelength light. For example, copper absorbs more green, blue, and violet light; aluminum and nickel absorb more ultraviolet light; while iron has a wider absorption range, absorbing not only ultraviolet light but also some visible light.

[0009] This invention positions the cell as a current transmission layer through a layered design. By setting a reflective layer on its surface, the absorption of short-wavelength light by base metals can be avoided, while reducing the overall manufacturing cost of the cell.

[0010] Furthermore, the reflective layer can be made of specialized reflective materials, such as high-purity silver or aluminum plating, or special optical coatings. These materials have a much higher reflectivity than the base metal substrate, efficiently reflecting light near the fine grid lines. The high reflectivity of the reflective layer can reflect this incident but unabsorbed light back into the cell, giving it a second chance to be captured by the light-absorbing layer. Understandably, the reflective layer at least covers the upper surface of the substrate away from the substrate. In actual manufacturing, the reflective layer may also extend from the upper surface of the substrate to the side; this embodiment does not impose any limitations on this.

[0011] It should be noted that in this embodiment, the substrate layer is a base metal, such as copper, which strongly absorbs short-wavelength light (blue-green light) and reflects long-wavelength light (yellow-red light). The reflective layer is mainly used to reduce the absorption of short-wavelength light by the copper paste, allowing the short-wavelength light to pass through the reflective layer and reach the substrate, thus achieving light utilization. By setting the light reflective layer, short-wavelength light is directly reflected to the substrate, and light is indirectly reflected to the back glass before illuminating the substrate. The difference between these two parts works together. The embodiments of this application improve the utilization of light reflection on the back of the solar cell, thereby increasing the back power of the photovoltaic module, which has the beneficial effect of improving the overall power and bifaciality of the photovoltaic module.

[0012] Optionally, in an embodiment of this application, the battery cell further includes a plurality of first connecting portions connected to the substrate layer, and along the extending direction of the fine grid lines, the reflective layer is disposed on the substrate layer and located between the first connecting portions. Optionally, in an embodiment of this application, the reflective layer includes a plurality of sub-reflective layers, which are spaced apart between the first connecting portion along the extending direction of the fine grid lines.

[0013] Optionally, in this embodiment, the sub-reflective layers adjacent to the fine grid lines are arranged facing each other along the extension direction perpendicular to the fine grid lines.

[0014] Optionally, in this embodiment, the sub-reflective layers on adjacent fine grid lines are staggered along the extension direction perpendicular to the fine grid lines.

[0015] Optionally, in this embodiment of the application, the battery cell further includes an insulating adhesive disposed on the substrate layer, and the width of the insulating adhesive is greater than the width of the fine grid lines along the extension direction perpendicular to the fine grid lines.

[0016] Optionally, in this embodiment, the outer surface of the reflective layer is undulating. Along the direction perpendicular to the battery cell, the maximum dimension between the reflective layer and the upper surface of the substrate is h, and the maximum dimension between the substrate layer and the upper surface of the substrate is h2, h1-h2=x*h2, 0.5≤x≤1.5; where 5μm

[0017] Optionally, in this embodiment of the application, along the extension direction perpendicular to the fine grid line, the width of the reflective layer is L1, the width of the substrate layer is L2, L1≤L2, and / or L2-L1≥2μm; wherein, 10μm<L1<100μm.

[0018] Optionally, in this embodiment, the length of the sub-reflective layer along the extending direction of the fine grid line is L3, where 0.50mm < L3 < 3.0mm.

[0019] Optionally, in this embodiment, the spacing between two adjacent sub-reflective layers along the extending direction of the fine grid line is L4, where 0.02mm < L4 < 1.0mm.

[0020] Optionally, in this embodiment of the application, the spacing between two adjacent sub-reflective layers along the extension direction perpendicular to the fine grid line is L5, where 0.10mm < L5 < 1.0mm.

[0021] Optionally, in this embodiment, the insulating adhesive and the reflective layer are spaced apart along the extension direction of the fine grid lines, and / or the spacing between the sub-reflective layer of the reflective layer and the insulating adhesive is L6, where 0.10mm < L6 < 1.0mm.

[0022] Optionally, in this embodiment of the application, the reflective layer and the first connecting portion are spaced apart along the extension direction of the fine grid line, and / or the spacing between the reflective layer and the first connecting portion is L7, 0.10mm < L7 < 1.0mm.

[0023] Optionally, in this embodiment of the application, the angle between the tangent at the extended end of the reflective layer and the substrate and the substrate is α, where 90° < α < 140°.

[0024] Optionally, in an embodiment of this application, the battery cell further includes a second connecting portion, the second connecting portion connecting at least two of the fine grid lines with the same polarity, and the insulating adhesive being located between the substrate and the second connecting portion and covering the substrate layer of at least some of the fine grid lines with opposite polarities.

[0025] ​Optionally, in this embodiment, the substrate further includes a semiconductor region, the fine gate lines are disposed in the semiconductor region, and the width of the insulating adhesive along the direction perpendicular to the fine gate lines is greater than the width of the semiconductor layer, so as to cover part of the gap between the semiconductor layers. Secondly, a photovoltaic module is also provided, comprising: a solar cell as described above; an interconnecting strip; the interconnecting strip being disposed along an extension direction perpendicular to the fine grid lines and covering at least a portion of the fine grid lines.

[0026] Optionally, in this embodiment of the application, the spacing between the reflective layer and the interconnecting strip along the extending direction of the fine grid line is L8, where 0.10mm < L8 < 2.0mm.

[0027] Optionally, in this embodiment of the application, the photovoltaic module further includes a busbar, which is disposed on at least a portion of the solar cells along the extension direction of the fine grid lines, and the busbar is connected to the interconnect strip; the reflective layer is disposed outside the overlapping area of ​​the busbar and the solar cells. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the cross-sectional structure of the fine grid lines of the battery cell along the direction perpendicular to the grid lines in the embodiments of this application. Figure 1 ; Figure 2 This is a schematic cross-sectional view of the fine grid lines of the battery cell along the direction perpendicular to the grid lines in the embodiments of this application. Figure 2 ; Figure 3 This is a schematic diagram of the distribution structure of a sub-reflective layer on a photovoltaic module in an embodiment of this application; Figure 4 This is a schematic diagram of the distribution structure of another sub-reflective layer on the photovoltaic module in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the battery cell in the embodiments of this application; Figure 6 This is a partial top view enlarged view of the battery cell in the embodiments of this application; Figure 7 This is a schematic cross-sectional view of the layered structure of the battery cell in an embodiment of this application; Figure 8 This is a graph showing the ratio of the reflectance of the insulating adhesive to the reflectance of the second connection in the embodiments of this application; Figure 9 This is a graph showing the reflectivity of the battery cells in the embodiments of this application; Figure 10 This is a reflectance curve diagram of the fine grid lines with a reflective layer and the fine grid lines without a reflective layer in the embodiments of this application.

[0029] Explanation of reference numerals in the attached figures: 10. Substrate; 20. Fine grid line; 21. Substrate layer; 22. Reflective layer; 221. Sub-reflective layer; 23. First connecting part; 30. Insulating adhesive; 40. Second connecting part; 50. Interconnecting strip; 60. Busbar; 70. Gap. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0032] The battery cells and photovoltaic modules provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0033] See Figure 1 An embodiment of this application provides a battery cell including a substrate 10 and fine grid lines 20, wherein a plurality of fine grid lines 20 are arranged in an array on the substrate 10; the fine grid lines 20 include a substrate layer 21 and a reflective layer 22, wherein the reflective layer 22 covers at least a portion of the substrate layer 21; the material of the substrate layer 21 includes base metals.

[0034] In this embodiment, multiple fine grid lines 20 are arranged in an array on the substrate 10. When the substrate 10 serves as the supporting foundation for the fine grid lines 20, its flatness and stability directly affect the consistency of the fine grid line 20 array. If the surface of the substrate 10 is flat, it provides a structural prerequisite for the efficient operation of the subsequent reflective layer 22.

[0035] Furthermore, the substrate layer 21 is made of base metals, such as copper, iron, aluminum, nickel, or their alloys, which are cheaper than precious metals, with copper being preferred. Base metals possess sufficient mechanical strength and conductivity to support the long-term adhesion of the reflective layer 22, preventing the reflective layer 22 from detaching and causing reflection failure. Simultaneously, they meet the basic conductivity requirements for the fine grid lines 20 to collect photogenerated carriers, without substantially affecting the charge transfer efficiency on the solar cell. Base metals themselves have a certain absorption capacity for short-wavelength light. For example, copper absorbs more green, blue, and violet light; aluminum and nickel absorb more ultraviolet light; while iron has a wider absorption range, absorbing not only ultraviolet light but also visible light.

[0036] This invention positions the cell as a current transmission layer through a layered design. By setting a reflective layer 22 on its surface, the absorption of short-wavelength light by base metals can be avoided, while reducing the overall manufacturing cost of the cell.

[0037] Furthermore, the reflective layer 22 can be made of a specialized reflective material, such as a high-purity silver or aluminum plating, or a special optical coating. These materials have a much higher reflectivity than the base metal substrate layer 21, efficiently reflecting light near the fine grid lines 20. The high reflectivity of the reflective layer 22 can reflect this incident but unabsorbed light back into the cell, giving it a second chance to be captured by the light-absorbing layer. Understandably, the reflective layer 22 at least covers the upper surface of the substrate layer 21 away from the substrate 10. In actual manufacturing, the reflective layer 22 may also extend from the upper surface of the substrate 10 to the side; this embodiment does not impose any limitations on this.

[0038] It should be noted that in this embodiment, the substrate layer 21 is a base metal, such as copper, which strongly absorbs short-wavelength light (blue-green light) and reflects long-wavelength light (yellow-red light). The reflective layer 22 is mainly used to reduce the absorption of short-wavelength light by the copper paste, allowing the short-wavelength light to pass through the reflective layer 22 and hit the substrate 10, thus achieving light utilization. By setting the light reflective layer 22, short-wavelength light is directly reflected to the substrate 10 through the reflective layer 22, and light is indirectly reflected to the back glass through the reflective layer 22 before illuminating the substrate 10. The difference between these two parts works together. The embodiments of this application improve the utilization of light reflection on the back of the solar cell, thereby increasing the back power of the photovoltaic module, which has the beneficial effect of improving the overall power and bifaciality of the photovoltaic module.

[0039] Optionally, in this embodiment of the application, the battery cell further includes a plurality of first connection portions 23 connected to the substrate layer 21, and along the extending direction of the fine grid lines 20, the reflective layer 22 is disposed on the substrate layer 21 and located between the first connection portions 23.

[0040] In this embodiment, there are multiple first connecting portions 23, which are directly and fixedly connected to the substrate layer 21, serving as electrical connection interfaces for the battery cells, such as for welding and conductive connections. The reflective layer 22 is only laid on the surface of the substrate layer 21 and is strictly limited to the area between the first connecting portions 23, without covering the first connecting portions 23 themselves. There is no contact or overlap between the reflective layer 22 and the first connecting portions 23. This ensures good reflectivity while saving the amount of reflective layer 22 used, thereby further saving production costs. At the same time, it reduces the risk that the reflective layer 22 may extend to the surface of the first connecting portions 23 due to process errors during manufacturing, increasing the contact resistance on the first connecting portions 23 and thus affecting the conductivity between the battery and the interconnect strip 50.

[0041] The reflective layer 22 can be further configured to contact the first connection portion 23. In this way, the coverage area of ​​the reflective layer 22 on the substrate layer 21 of the fine grid line 20 is increased, the exposed area of ​​the substrate layer 21 is reduced, the absorption of light by the substrate layer 21 can be better avoided, and the reflection of light by the reflective layer 22 is increased.

[0042] In this embodiment, the first connecting portion 23, as a key electrical connection structure, is exposed and not covered by the reflective layer 22, enabling smooth conductive connection with external components and ensuring circuit continuity. The reflective layer 22 precisely fills the area on the fine grid lines 20 located between the first connecting portions 23, fully utilizing the non-electrically connected areas on the substrate layer 21, reducing light loss caused by light absorption by the substrate layer 21, and improving light reflection and recovery efficiency.

[0043] like Figure 5 As shown, optionally, in this embodiment of the application, the reflective layer 22 is continuously disposed between the first connecting portions 23.

[0044] In this embodiment, the reflective layer 22 is laid only on the surface of the substrate layer 21, forming a continuous and uninterrupted reflective layer 22 covering the substrate layer 21 in the region between the first connecting portions 23.

[0045] In this embodiment, the continuous reflective layer 22 reduces the risk of edge lifting and detachment, improves its adhesion stability, and eliminates the need for additional alignment of segmented interfaces, reducing processing difficulty and error risk. Furthermore, the continuous structure exhibits stronger overall integrity and superior wear and detachment resistance. The continuous reflective layer 22 can more comprehensively reflect light illuminating non-electrically connected areas, reducing light energy loss. Moreover, the continuously arranged reflective layer 22 can cover more of the substrate layer 21, providing protection against oxidation or corrosion.

[0046] like Figure 3 , Figure 4As shown, optionally, in this embodiment of the application, the reflective layer 22 is disposed discontinuously between the first connecting portions 23. The reflective layer 22 includes a plurality of sub-reflective layers 221, which are spaced apart between the first connecting portions 23 along the extending direction of the fine gate line 20.

[0047] In this embodiment, the reflective layer 22 is composed of multiple independent sub-reflective layers 221, rather than a continuous whole. The arrangement direction of the sub-reflective layers 221 is consistent with the extension direction of the fine gate lines 20. All sub-reflective layers 221 are located on the surface of the substrate layer 21 between the first connecting portions 23, and the sub-reflective layers 221 are spaced apart from each other. The lengths of the sub-reflective layers 221 along the extension direction of the fine gate lines can be set to be equal or unequal; this embodiment does not limit this.

[0048] In this embodiment, multiple sub-reflective layers 221 can match the regional morphology between the first connecting portions 23. Even if the fine grid lines 20 are complexly distributed, they can still cover the effective optical area through spaced arrangement, reducing light absorption by the substrate layer 21. The independently spaced design of the sub-reflective layers 221 can reduce the problem of cell warping caused by stress concentration due to thermal expansion and contraction. At the same time, it is also convenient to adjust the layout according to the cell size and the spacing of the first connecting portions 23 to adapt to different specifications of products. Furthermore, the reflective layer 22 reduces the amount of reflective layer 22 used by using multiple spaced sub-reflective layers 221, which can not only reduce the weight of the cell, but also save production costs.

[0049] like Figure 3 As shown, optionally, in this embodiment of the application, the sub-reflective layers 221 of adjacent fine gate lines 20 are arranged facing each other along the extension direction perpendicular to the fine gate line 20.

[0050] In this embodiment, the sub-reflective layers 221 corresponding to two adjacent fine grid lines 20 are aligned or directly opposite each other along the square vertical axis of the fine grid lines 20, forming a regular array layout. The directly opposite sub-reflective layers 221 form a regular arrangement, which can uniformly cover the gap area between adjacent fine grid lines 20, avoiding the risk of cell cracking caused by localized stress concentration. Furthermore, this design avoids localized light reflection blind spots, resulting in more uniform light reflection and improved overall aesthetics. Further, the regularly opposite layout can match the incident light path of the cell, reducing light scattering loss between the sub-reflective layers 221 and improving the recovery rate of reflected light. The directly opposite design of the sub-reflective layers 221 standardizes and modularizes the layout, reducing positioning difficulty during processing, and facilitating subsequent alignment with other optical components, thereby improving overall product manufacturing efficiency and yield.

[0051] like Figure 4 As shown, optionally, in this embodiment of the application, the sub-reflective layers 221 on adjacent fine gate lines 20 are staggered along the extension direction perpendicular to the fine gate line 20.

[0052] In this embodiment, the sub-reflective layers 221 of adjacent fine gate lines 20 are staggered in the direction perpendicular to the fine gate line 20. It should be noted that the staggered arrangement includes complete staggering and partial staggering; this embodiment does not specifically limit this and can be determined according to actual conditions. In a preferred embodiment, each sub-reflective layer 221 on a fine gate line 20 is positioned precisely corresponding to the interval region between two sub-reflective layers 221 on adjacent fine gate lines 20, forming a complementary distribution.

[0053] In this embodiment, the staggered layout allows the sub-reflective layers 221 to fill the gaps between adjacent fine grid lines 20, significantly reducing light leakage and reflection. This improves overall light reflection utilization while saving on the amount of reflective layers 22, and also better disperses local stress in the solar cell, reducing the risk of cell warping. The staggered distribution of the sub-reflective layers 221 can reflect light incident at different angles in multiple directions, making it particularly suitable for scenarios with scattered light or non-parallel incident light. The complementary staggered layout ensures that the non-electrically interconnected area of ​​the entire solar cell is uniformly covered by the sub-reflective layers 221, reducing the risk of warping caused by localized stress concentration and better reflecting light, resulting in more stable photoelectric conversion efficiency of the solar cell.

[0054] like Figures 3 to 7 As shown, optionally, in this embodiment of the application, the battery cell further includes an insulating adhesive 30, which is disposed on the substrate layer 21. Along the extension direction perpendicular to the fine grid lines 20, the width of the insulating adhesive 30 is greater than the width of the fine grid lines 20. The insulating adhesive 30 and the reflective layer 22 are spaced apart, or they can be in contact. Preferably, the reflective layer 22 and the insulating adhesive 30 are spaced apart.

[0055] In this embodiment, the insulating adhesive 30 isolates different conductive areas inside the battery cell or external components, avoiding the risk of leakage and short circuit. Along the extension direction perpendicular to the fine grid lines 20, the width of the insulating adhesive 30 is greater than the width of the fine grid lines 20, allowing for more comprehensive coverage of potential leakage areas around the fine grid lines 20, ensuring current collection and transmission performance. The insulating adhesive 30 is spaced apart from the reflective layer 22, avoiding light reflection loss caused by the insulating adhesive 30 blocking the reflective layer 22. The insulating adhesive 30 is only disposed in a specific area of ​​the substrate layer 21, without changing the original core layout of the first connection portion 23, the fine grid lines 20, and the sub-reflective layer 221, adapting to existing processing techniques.

[0056] like Figure 1As shown, the cross-section of the substrate layer 21 is approximately rectangular or triangular. In this embodiment, the reflective layer 22 is disposed on the surface of the substrate layer 21, and its outline is the same as or similar to that of the substrate layer 21 to increase the connection strength between the reflective layer 22 and the substrate layer 21. The outer surface of the reflective layer 22 is undulating. Along the direction perpendicular to the solar cell, the maximum dimension between the reflective layer 22 and the upper surface of the substrate 10 is h1, and the maximum dimension between the substrate layer 21 and the upper surface of the substrate 10 is h2, where h1-h2=x*h2, 0.5≤x≤1.5; and 5μm

[0057] In this embodiment, the core function of the substrate layer 21 of the fine gate line 20 is to collect photogenerated carriers, and the function of the reflective layer 22 is to reflect light to improve light utilization. The ratio of the thickness of the reflective layer 22 to the thickness of the substrate layer 21 directly determines the current transmission performance and reflection performance.

[0058] If h1-h2<0.5h2 (i.e. h1<1.5h2): the thickness of the reflective layer 22 is insufficient, some light will penetrate the reflective layer 22 instead of being reflected by the reflective layer 22, resulting in insufficient reflection and a reduction in the light utilization improvement effect; If h1-h2>1.5h2 (i.e., h1>2.5h2): Excessive thickness of the reflective layer 22 may lead to an overuse of the reflective layer 22, potentially covering the solar cell, reducing the effective light-receiving area of ​​the solar cell, and directly decreasing light absorption. Furthermore, an excessively thick reflective layer 22 increases the overall weight of the fine grid lines 20, making them more prone to breakage and increasing the risk of microcracks in the solar cell, thus affecting its lifespan. The setting of h1-h2=x*h2, with 0.5≤x≤1.5, precisely matches the thickness of the extended reflective layer 22 with the thickness of the substrate layer 21. This ensures that the reflective layer 22 covers the upper surface of the substrate layer 21, maximizing the light reflection range, without excessively extending and reducing the effective light-receiving area of ​​the solar cell. This guarantees that each part of the reflective layer 22 serves the core objective of improving light utilization, avoiding functional deviation. Designing the thickness within a reasonable range avoids the reflective layer 221 becoming too thin, reducing light transmission, and has the beneficial effect of increasing light reflection and improving light utilization. It also reduces the risk of microcracks in the solar cell, thus improving its lifespan.

[0059] In practical applications, the thickness of the reflective layer 22 is typically between 5 μm and 30 μm. The thickness of the substrate layer 21, also typically between 5 μm and 30 μm, is then added, while the thickness of the fine gate lines 20 can be approximately 10–60 μm. Furthermore, since the substrate layer 21 may exhibit structures such as protrusions or spikes, the thickness of the reflective layer 22 should be greater than the fluctuation value of the substrate layer 21 (typically 18–25 μm).

[0060] ​Furthermore, the dimensional ratio of the reflective layer 22 and the substrate layer 21 is precisely controlled through quantitative constraints to achieve precise control of material usage, which also has the beneficial effect of avoiding cost waste.

[0061] Optionally, in this embodiment, along the extension direction perpendicular to the fine grid line 20, the width of the reflective layer 22 is L1, the width of the substrate layer 21 is L2, L1≤L2, and / or L2-L1≥2μm; wherein, 10μm<L1<100μm.

[0062] In this embodiment, L1≤L2 ensures that the reflective layer 22 is located on the surface of the substrate layer 21 and does not exceed the boundary of the substrate layer 21. At the same time, L2-L1≥2μm can accommodate positioning errors during processing, taking into account both practicality and process feasibility.

[0063] In practical applications, the width of the reflective layer 22 is generally 10μm < L1 < 100μm.

[0064] L1 > 10 μm ensures that the reflective layer 22 has a sufficient area to cover the effective optical area on the substrate layer 21, avoiding insufficient light reflection due to excessive narrowness; while L1 < 100 μm avoids the reflective layer 22 being too wide and occupying too much space, adapting to the dense layout of components such as fine gate lines 20 and semiconductor regions, balancing optical function and structural compactness.

[0065] In this embodiment, L1 > 10 μm ensures that the reflective layer covers the effective optical area of ​​the substrate layer and guarantees the amount of light reflection, while L1 < 100 μm prevents the reflective layer 22 from being too wide and covering too much area. This width range allows the reflective layer 22 to match the gap width between the fine grid lines 20, so as not to block the silicon substrate of the solar cell, and to maximize the coverage of the substrate layer 21 of the grid lines 20 to improve light utilization.

[0066] like Figure 3 As shown, optionally, in this embodiment of the application, the length of the sub-reflective layer 221 along the extending direction of the fine gate line 20 is L3, 0.5mm < L3 < 3.0mm.

[0067] In this embodiment, L3 > 0.5 mm avoids the sub-reflective layer 221 being too short, resulting in insufficient effective reflective area. It can fully cover the longitudinal optical area between the first connecting parts 23, ensuring the total amount of light reflection and supporting photoelectric conversion efficiency. L3 < 3.0 mm can flexibly match different spacing designs of the first connecting parts 23, especially suitable for battery cell structures with dense first connecting parts 23 and small spacing. It avoids the sub-reflective layer 221 being too long and interfering with the first connecting parts 23, while reserving a reasonable interval for adjacent sub-reflective layers 221 (meeting the requirements of staggered layout).

[0068] It should be noted that 0.5mm < L3 < 3.0mm allows for precise molding using existing equipment while also being compatible with processing errors in the length direction, reducing issues such as end deformation and dimensional deviations. This length range balances the structural stability of the sub-reflective layer 221 and its bonding force with the substrate layer 21, avoiding edge stress concentration (prone to detachment) due to excessive length or overall flatness reduction due to excessive length, thus adapting to long-term use scenarios.

[0069] Optionally, in this embodiment of the application, along the extension direction of the fine gate line 20, the spacing between two adjacent sub-reflective layers 221 is L4, where 0.02mm < L4 < 1.0mm.

[0070] In this embodiment, L4 > 0.02 mm avoids the increased processing difficulty caused by excessively narrow spacing (such as edge adhesion and dimensional deviation of the sub-reflective layer 221), reserving sufficient operational redundancy for processes such as coating formation and photolithography positioning, and ensuring compatibility with the precision of existing equipment. L4 < 1.0 mm prevents the spacing from being too large, which would result in a poor reflection effect. Combined with the previous staggered layout, it ensures the overall light reflection coverage and avoids energy waste. More balanced structural stress: The reasonable spacing design can alleviate the mutual compression or pulling of the sub-reflective layers 221 during thermal expansion and contraction, reducing the risk of edge cracking and detachment, especially suitable for the stability requirements of long-term outdoor use. In addition, the spacing between the sub-reflective layers 221 effectively disperses the local or overall stress of the battery cell, reducing the risk of battery cell warping and microcracks.

[0071] Optionally, in this embodiment, the spacing between two adjacent sub-reflective layers 221 along the extension direction perpendicular to the fine gate line 20 is L5, where 0.10mm < L5 < 1.0mm.

[0072] In this embodiment, L5 > 0.10 mm, and the reflective layer 221 can directly reflect the light from the transparent solar cell to the surface of the solar cell, reducing the light reflection path and loss. L5 < 1.0 mm can prevent the reflective layer 22 from being too wide and extending to the substrate 10, thereby blocking the substrate 10 from absorbing and utilizing light.

[0073] It should be noted that setting the range of 0.10mm < L5 < 1.0mm can directly reflect the light from the transparent solar cell to the surface of the solar cell, reducing the light reflection path and loss. At the same time, it avoids the reflective layer 22 being too wide and blocking the substrate 10, thereby improving the absorption and utilization rate of light by the substrate 10.

[0074] Optionally, in this embodiment, the reflective layer 22 and the insulating adhesive 30 are spaced apart along the extension direction of the fine grid line 20, and / or the spacing between the sub-reflective layer 221 of the reflective layer 22 and the insulating adhesive 30 is L6, 0.10mm < L6 < 1.0mm.

[0075] In this embodiment, L6 > 0.10 mm prevents the sub-reflective layer 221 from contacting the insulating adhesive 30. This avoids the insulating adhesive 30 blocking the sub-reflective layer 221, which would cause light reflection loss, and also prevents the reflective layer 22 from affecting the insulating performance of the insulating adhesive 30, ensuring that the two functions independently and stably. L6 < 1.0 mm avoids excessive spacing that would waste the effective space of the substrate layer 21. At the same time, the spacing of 0.10 mm to 1.0 mm can accommodate positioning errors during processing and also reserves deformation redundancy for structural deformation caused by thermal expansion and contraction, preventing the two from squeezing or colliding with each other due to deformation.

[0076] Optionally, in this embodiment, the reflective layer 22 and the first connecting portion 23 are spaced apart along the extending direction of the fine grid line 20, and the distance between the reflective layer 22 and the first connecting portion 23 is L7, where 0.10mm < L7 < 1.0mm.

[0077] In this embodiment, L7 > 0.10 mm avoids the sub-reflective layer 221 from being too close to the first connecting part 23, which would affect the electrical interconnection performance of the first connecting part 23. Simultaneously, it provides sufficient space for welding, wire connection, and other operations of the first connecting part 23, ensuring smooth electrical connection operations. The spacing design prevents damage to the sub-reflective layer 221 during processing or use, such as high temperatures during welding, thus ensuring the integrity and light reflection efficiency of the reflective layer 22. L7 < 1.0 mm avoids excessively wide spacing that would occupy too much space, which would be detrimental to the overall structural compactness. At the same time, the spacing range of 0.10 mm < L7 < 1.0 mm is compatible with positioning deviations during processing, such as molding offset of the first connecting part 23 and layout errors of the sub-reflective layer 221, reducing mutual overlap due to excessively tight dimensions and lowering the production defect rate.

[0078] like Figure 2 As shown, optionally, in this embodiment of the application, the angle between the tangent at the extended end of the reflective layer 22 and the substrate 10 and the substrate 10 is α, where 90° < α < 140°.

[0079] In this embodiment, the angle formed by the tangent of the substrate 10 at the extended end of the reflective layer 22, i.e., the edge furthest from its main body, and the reflective layer 22 is α. This angle is strictly limited to between 90° and 140°, exhibiting an outward tilt. Specifically, α is not less than 90° to prevent the end from bending inward or becoming perpendicular to the substrate 10, and not greater than 140° to prevent excessive tilting that could lead to structural weakness or light reflection deviation. In this embodiment, the 90°-140° tilt angle allows the reflective layer 22 to more efficiently reflect incident light, especially oblique light, to the photoelectric conversion area of ​​the solar cell, rather than escaping outward or reflecting to ineffective areas, significantly increasing the generation of photogenerated carriers. Simultaneously, it avoids excessively large α angles that could cause reflected light to deviate, ensuring that the reflected light covers the effective light-absorbing area and maximizing light utilization. Compared to vertical or excessive tilting, this reduces light refraction loss and improves light energy recovery efficiency.

[0080] In addition, the angle of 90° < α < 140° avoids the formation of sharp angles and stress concentration between the end and the substrate 10, reducing the risk of cracking and detachment. Furthermore, the angle of 90° < α < 140° does not conflict with existing width constraints, staggered layouts, and other design features, and is compatible with the overall processing flow.

[0081] like Figure 6 , Figure 7 As shown, optionally, in this embodiment of the application, the battery cell further includes a second connecting portion 40, which connects at least two fine grid lines 20 with the same polarity, and the insulating adhesive 30 is located between the substrate 10 and the second connecting portion 40 and covers the substrate layer 21 of at least some of the fine grid lines 20 with different polarities.

[0082] In this embodiment, the core function of the second connecting portion 40 is to connect at least two fine gate lines 20 with the same polarity to form a common-polarity bus channel. The insulating adhesive 30 is sandwiched between the substrate layer 21 and the second connecting portion 40, and must cover at least a portion of the substrate layer 21 area corresponding to the fine gate lines 20 with opposite polarities.

[0083] In this embodiment, the second connection portion 40 serves as a current-collecting structure for the same-polarity fine grid lines 20, enabling the concentrated outflow of current collected by multiple fine grid lines 20, reducing losses along the current transmission path, and improving the overall conductivity of the solar cell. The insulating adhesive 30 is located between the substrate layer 21 of the opposite-polarity fine grid lines 20 and the second connection portion 40, and covers the substrate layer 21 corresponding to the opposite-polarity fine grid lines 20. This isolates the second connection portion 40 from the opposite-polarity fine grid lines 20, preventing short-circuit risks caused by direct contact between the same-polarity second connection portion 40 and the opposite-polarity fine grid lines 20. The insulating adhesive 30 simultaneously serves as an adhesive, enhancing the connection stability between the second connection portion 40 and the substrate layer 21, and providing insulation, isolating the opposite polarity. This eliminates the need for additional adhesive components, simplifying the structure while improving reliability. The portion of the substrate layer 21 covered by the insulating adhesive 30 does not have a reflective layer. The layout of the second connection portion 40 and the insulating adhesive 30 does not affect the optical function of the sub-reflective layer 221 or the current collection of the fine grid lines 20, thus complementing the existing structure.

[0084] Optionally, in this embodiment, the substrate 10 further includes different semiconductor regions, with fine gate lines 20 disposed in the semiconductor regions, and the width of the insulating adhesive 30 in the direction perpendicular to the fine gate lines 20 being greater than the width of the semiconductor regions, so as to cover the gap 70 between some of the semiconductor regions.

[0085] In this embodiment, the semiconductor region is the core functional layer for photoelectric conversion of the battery cell. It is perpendicular to the direction of the fine grid line 20. The width of the insulating adhesive 30 is greater than the width of the semiconductor region, and the insulating adhesive 30 extends to cover part of the gap 70 area between adjacent semiconductor regions, without affecting the photoelectric conversion function of the semiconductor region itself.

[0086] In this embodiment, the insulating adhesive 30 is not randomly applied, but rather disposed in the gaps perpendicular to the width direction of the fine gate lines 20, that is, in the uncovered areas of the substrate 10 between the fine gate lines 20, and connected to the substrate 10. The lower surface of the insulating adhesive 30 is directly attached to the surface of the substrate 10. The insulating adhesive 30 in this application possesses both insulating and reflective properties. On the one hand, its insulating properties prevent electrical short circuits between adjacent fine gate lines 20; on the other hand, its reflective properties reflect light incident on the gaps 70 of the partial semiconductor regions, solving the light loss problem caused by the lack of reflective structures in traditional semiconductor regions. The coverage of the insulating adhesive 30 in the gaps 70 between the partial semiconductor regions increases the adhesion of the insulating adhesive 30 and transforms the gaps 70 between the partial semiconductor regions from light loss regions into light reflection gain regions, avoiding the waste of light energy caused by the lack of reflective structures in semiconductor regions in traditional designs, and directly increasing the total number of photogenerated carriers.

[0087] Furthermore, in the embodiments of this application, the reflectivity of the insulating adhesive 30 is R1, the reflectivity of the second connecting part 40 (taking copper as an example) is R2, and the reflectivity of the insulating adhesive 30 plus the reflectivity of the second connecting part 40 is R3, where R1 < R2 and R3 > R2.

[0088] like Figure 8 As shown, it should be noted that the ratio of R1 to R2 varies between [0.001, 1.277]. In the 300–342 nm wavelength range, the ratio is ≥1; in the 342–1200 nm wavelength range, the ratio is less than 1. This variation in reflectivity ratio indicates that for light in the 300–342 nm wavelength range, the reflectivity of the insulating adhesive 30 is greater than that of the second connecting part 40 (taking copper as an example). Therefore, by providing the insulating adhesive 30, the reflection of light in the 300–342 nm wavelength range is increased, while the absorption of light in this wavelength range by the second connecting part 40 (taking copper as an example) is reduced. Furthermore, as... Figure 9 As shown, after the insulating adhesive 30 and the second connecting part 40 are stacked, the reflectivity R3 is improved compared to the reflectivity R1 of the insulating adhesive 30 and the reflectivity R2 of the second connecting part 40. For example, for light in the 473-812nm wavelength band, R3 is significantly greater than R2; for light in the 812-1200nm wavelength band, R3 is still greater than R2. In other words, by setting the insulating adhesive 30, the reflectivity of the insulating adhesive 30 and the reflectivity of the second connecting part 40 are superimposed, thereby improving the reflectivity of light in the 473-1200nm wavelength band, thus increasing the light absorption and utilization rate of the battery and improving the module efficiency.

[0089] It should be noted that R3 is not simply the sum of the reflectivity values ​​of R2 and R1, but rather a reflection-enhancing structure formed by the spatial nesting of the insulating adhesive 30 and the second connecting part 40, the complementary reflection paths, and the synergistic material properties. The light energy from the two reflections is superimposed to form the total reflectivity R3, and because the double reflection reduces light escape, R3 > R2 is ultimately achieved.

[0090] In addition, such as Figure 10 As shown, for light with a wavelength less than 750nm, the reflectivity of the fine grating 20 without the reflective layer 22 is low, especially when the light wavelength is less than 550nm, the reflectivity is less than 20%. However, the fine grating 20 with the reflective layer 22 in this application has a reflectivity of more than 40% in the same wavelength band, thereby improving the reflectivity of the fine grating 20 for light.

[0091] It should be noted that the reflective layer 22 includes a solute and a solvent. The solute is made of metallic reflective particles or non-metallic reflective particles, and the solvent is made of any one of ketone solvents, ester solvents or alcohol solvents.

[0092] In the embodiments of this application, the metallic reflective particles may be solvent-resistant titanium alloy powder, electroplating powder, metal powder, or aluminum powder; the non-metallic reflective particles may be glass microspheres, reflective microstructures, titanium oxide, metal oxides, zinc oxide, or bismuth oxychloride (BiOCl) (which is susceptible to light and heat decomposition and is gradually being used less frequently). They may also be mica + titanium dioxide (TiO2) composite powder, with mica as the substrate and coated with a nano-scale TiO2 layer, which has the characteristics of strong diffuse reflection, good stability, and low cost; or they may be polymethyl methacrylate (PMMA) microspheres.

[0093] Furthermore, the solvent system in this application has the following basic characteristics: the light-curing resin (such as epoxy acrylate, polyurethane acrylate) and the reactive diluent (such as tripropylene glycol diacrylate) are polarly matched, and polar solvents (such as acetone, ethyl acetate) are usually selected to avoid turbidity of the system or separation after curing due to poor compatibility.

[0094] Common solvent types can be ketones, such as acetone (boiling point 56℃) and butanone (79.6℃); esters, such as ethyl acetate (77℃) and isopropyl acetate (88℃); and alcohols, such as isopropanol (82.5℃). However, it should be noted that alcohols may react with certain photoinitiators (such as tertiary amine co-initiators).

[0095] like Figure 3 , 5 As shown, embodiments of this application also provide a photovoltaic module, including: a solar cell as described above; an interconnect strip 50; the interconnect strip 50 is disposed along an extension direction perpendicular to the fine grid line 20 and covers at least a portion of the fine grid line 20.

[0096] In this embodiment, the interconnecting strip 50 (which may be a solder ribbon) is arranged perpendicular to the fine grid line 20, covering a portion of the fine grid line 20. The interconnecting strip 50 serves as a conductive connection carrier between the solar cells and must form a reliable electrical connection with the fine grid line 20. The interconnecting strip 50's perpendicular arrangement to the fine grid line 20 allows for rapid collection of current gathered from multiple fine grid lines 20. Simultaneously, the partial coverage design of the interconnecting strip 50 with the fine grid line 20 ensures a large welding contact area and improves connection reliability. The interconnecting strip 50 only covers a portion of the fine grid line 20, avoiding large-area obstruction of the reflective layer 22 on the surface of the solar cell, thus not affecting the light reflection function of the reflective layer 22 and ensuring the photoelectric conversion efficiency of the solar cell.

[0097] It should be noted that the layout of the interconnecting strip 50 does not conflict with the spatial arrangement of other functional components, ensuring that the overall structure of the photovoltaic module is compact and coordinated.

[0098] Optionally, in this embodiment, the spacing between the reflective layer 22 and the interconnect strip 50 along the extending direction of the fine grid line 20 is L8, where 0.10mm < L8 < 2.0mm.

[0099] In this embodiment, along the extension direction of the fine grid line 20, the spacing L8 between the reflective layer 22 and the interconnect strip 50 is strictly controlled between 0.10mm and 2.0mm. They are non-contacting and non-overlapping, maintaining an independent layout. The spacing area is located only between the reflective layer 22 and the interconnect strip 50, forming an isolation transition zone between the optical functional area (reflective layer 22) and the electrical interconnect area (interconnect strip 50), and does not involve core functional components. The spacing between the reflective layer 22 and the interconnect strip 50 further prevents the reflective layer 22 from adversely affecting the electrical connection performance of the interconnect strip 50 itself when the interconnect strip 50 is misaligned after welding, thus improving the overall reliability of the component.

[0100] In this embodiment, L8 > 0.10 mm effectively isolates the reflective layer 22 from the interconnect strip 50, preventing the interconnect strip 50 from shifting position after welding, which would affect the reflection of the reflective layer 22 and the electrical connection performance of the interconnect strip 50 itself. L8 < 2.0 mm avoids excessive spacing that would waste the surface space of the photovoltaic module, while reserving deformation redundancy for the thermal expansion and contraction of the photovoltaic module (such as high and low temperature cycling).

[0101] It should be noted that the aforementioned interval range of 0.10mm < L8 < 2.0mm is also compatible with the welding positioning error of the interconnecting strip 50. The interval design neither obstructs the effective reflection area of ​​the reflective layer 22 nor affects the current collection of the fine grid line 20 by the interconnecting strip 50, thus achieving the non-interference and synergistic performance of optical and electrical connection functions.

[0102] Optionally, in this embodiment, the photovoltaic module further includes a busbar 60, which is disposed on at least a portion of the solar cells along the extending direction of the fine grid lines 20, and the busbar 60 is connected to the interconnect strip 50. Further, the reflective layer 22 is disposed outside the overlapping area between the busbar 60 and the solar cells.

[0103] In this embodiment, the busbar 60 is arranged along the extension direction of the fine grid line 20, covering only a portion of the cell area and not completely obscuring the semiconductor area or sub-reflective layer 221. It is fixedly connected to the interconnect bar 50, forming a current-carrying channel. The busbar 60, arranged along the direction of the fine grid line 20, can quickly collect the current transmitted by multiple interconnect bars 50, shortening the overall current transmission path of the module and reducing parallel resistance losses, making it particularly suitable for module designs with multiple cells connected in series and parallel. The connection between the busbar 60 and the interconnect bar 50 forms a rigid electrical connection network, improving the module's resistance to vibration and deformation during transportation, installation, and long-term use, and reducing the risk of loosening or detachment of connection points.

[0104] Furthermore, in this embodiment, the busbar 60 covers a portion of the battery cell area along the direction of the fine grid line 20, i.e., the overlapping area, and the reflective layer 22 is only distributed on the surface of the substrate layer 21 outside this overlapping area. The overlapping area is the connection area between the busbar 60 and the battery cell, and the two achieve a clear functional division through a non-overlapping design. In this embodiment, the reflective layer 22 avoids the shading area of ​​the busbar 60, maximizing the retention of the effective reflective area, ensuring that the reflective layer 22 can fully reflect light, avoiding the waste of light energy caused by the shading of the busbar 60, and ensuring the photoelectric conversion efficiency of the battery cell. The overlapping area between the busbar 60 and the battery cell is free from interference from the reflective layer 22, and can directly form a stable connection with the conductive components of the battery cell, avoiding the insulation or foreign matter characteristics of the reflective layer 22 from affecting the welding quality and conductivity of the busbar and the interconnect. In addition, the non-overlapping design reduces the contact stress of different functional components, avoids interlayer peeling caused by material differences during thermal expansion and contraction, reduces the unnecessary amount of reflective layer, and lowers production costs.

[0105] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0106] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A type of battery cell, characterized in that, It includes a substrate (10) and fine grid lines (20), with a plurality of the fine grid lines (20) arranged in an array on the substrate (10); The fine grid line (20) includes a substrate layer (21) and a reflective layer (22), wherein the reflective layer (22) covers at least a portion of the substrate layer (21); The material of the substrate layer (21) includes base metals.

2. The battery cell according to claim 1, characterized in that, The battery cell also includes a plurality of first connection portions (23) connected to the substrate layer (21). Along the extension direction of the fine grid line (20), the reflective layer (22) is disposed on the substrate layer (21) and located between the first connection portions (23).

3. The battery cell according to claim 2, characterized in that, The reflective layer (22) includes a plurality of sub-reflective layers (221), which are spaced apart between the first connecting portion (23) along the extending direction of the fine grid line (20).

4. The battery cell according to claim 3, characterized in that, Along the extension direction perpendicular to the fine grid line (20), the sub-reflective layers (221) adjacent to the fine grid line (20) are arranged facing each other.

5. The battery cell according to claim 3, characterized in that, Along the extension direction perpendicular to the fine grid line (20), the sub-reflective layers (221) on adjacent fine grid lines (20) are staggered.

6. The battery cell according to claim 1, characterized in that, The battery cell also includes an insulating adhesive (30), which is disposed on the substrate layer (21) along the extension direction perpendicular to the fine grid line (20), and the width of the insulating adhesive (30) is greater than the width of the fine grid line (20).

7. The battery cell according to any one of claims 1 to 3, characterized in that, The outer surface of the reflective layer (21) is undulating. Along the direction perpendicular to the battery cell, the maximum dimension between the reflective layer (22) and the upper surface of the substrate (10) is h1, and the maximum dimension between the substrate layer (21) and the upper surface of the substrate (10) is h2. h1-h2 = x*h2, 0.5≤x≤1.5; Among them, 5μm < h1 < 30μm, 5μm < h2 < 30μm.

8. The battery cell according to any one of claims 1 to 3, characterized in that, Along the extension direction perpendicular to the fine grid line (20), the width of the reflective layer (22) is L1, the width of the substrate layer (21) is L2, L1≤L2, and / or L2-L1≥2μm. Among them, 10μm < L1 < 100μm.

9. The battery cell according to claim 3, characterized in that, Along the extension direction of the fine grid line (20), the length of the sub-reflective layer (221) is L3, 0.5mm < L3 < 3.0mm.

10. The battery cell according to claim 3, characterized in that, Along the extension direction of the fine grid line (20), the spacing between two adjacent sub-reflective layers (221) is L4, 0.02mm < L4 < 1.0mm.

11. The battery cell according to claim 3, characterized in that, Along the extension direction perpendicular to the fine grid line (20), the spacing between two adjacent sub-reflective layers (221) is L5, 0.10mm < L5 < 1.0mm.

12. The battery cell according to claim 6, characterized in that, Along the extension direction of the fine grid line (20), the insulating adhesive (30) and the reflective layer (21) are spaced apart, and / or, the spacing between the sub-reflective layer (221) of the reflective layer (22) and the insulating adhesive (30) is L6, 0.10mm < L6 < 1.0mm.

13. The battery cell according to claim 2, characterized in that, Along the extension direction of the fine grid line (20), the reflective layer (22) is spaced apart from the first connecting portion (23), and / or the distance between the reflective layer (22) and the first connecting portion (23) is L7, 0.10mm < L7 < 1.0mm.

14. The battery cell according to any one of claims 1-3, characterized in that, The angle between the tangent of the extended end of the reflective layer (22) at the substrate (10) and the substrate (10) is α, where 90° < α < 140°.

15. The battery cell according to claim 6, characterized in that, The battery cell also includes a second connecting portion (40), which connects at least two of the fine grid lines (20) with the same polarity. The insulating adhesive (30) is located between the substrate (10) and the second connecting portion (40) and covers the substrate layer (21) of the fine grid lines (20) with at least some of the opposite polarity.

16. The battery cell according to claim 6, characterized in that, The substrate (10) further includes a semiconductor region, the fine gate line (20) is disposed in the semiconductor region, and the insulating adhesive (30) has a width greater than the width of the semiconductor region in a direction perpendicular to the fine gate line (20) to cover part of the gap (70) between the semiconductor regions.

17. A photovoltaic module, characterized in that, include: The battery cell as described in any one of claims 1-16; Interconnected strip (50); The interconnecting strip (50) is arranged in a direction perpendicular to the extension of the fine grid line (20) and covers at least a portion of the fine grid line (20).

18. The photovoltaic module according to claim 17, characterized in that, Along the extension direction of the fine grid line (20), the spacing between the reflective layer (22) and the interconnect strip (50) is L8, 0.10mm < L8 < 2.0mm.

19. The photovoltaic module according to claim 17 or 18, characterized in that, The photovoltaic module further includes a busbar (60), which is disposed on at least a portion of the solar cells along the extension direction of the fine grid lines (20), and the busbar (60) is connected to the interconnecting strip; The reflective layer (21) is disposed outside the overlapping area between the busbar (60) and the battery cell.

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