Solar cell, cell module and photovoltaic system

Abstract

The invention is applicable to the field of photovoltaic technology, and provides a solar cell, a cell module and a photovoltaic system.The solar cell comprises a silicon substrate and an electrode arranged on the silicon substrate, and the electrode comprises a bus grid line; the silicon substrate comprises a doping layer; the bus grid line comprises a connecting conductor and a fine grid line; the connecting conductors extend along a first direction, and the fine grid lines are arranged on the surfaces, facing the silicon substrate, of the connecting conductors; the connecting conductor is in non-physical contact with the doping layer, and the fine grid line is in physical contact with the doping layer. The fine grid lines collect current carriers generated by the silicon substrate, current carrier loss caused by shielding of the connecting conductors is reduced, the connecting conductors are used for transmitting the collected current carriers, and the transmission efficiency is high.

Description

Technical Field

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

[0002] As an efficient and clean energy conversion device, solar cells are widely used in various photovoltaic power generation systems. Solar cells include a silicon substrate and electrodes arranged on the silicon substrate. The electrodes and the silicon substrate are in ohmic contact and are responsible for effectively collecting electrons and holes (carriers) generated by silicon materials under sunlight and then converting them into usable electrical energy.

[0003] In the traditional solar cell structure, in order to better collect the current from each electrode, a busbar line is added to the surface of the cell. The busbar line itself does not have the function of collecting carriers, but only serves as a channel for current collection. When sunlight shines on the surface of the solar cell, most of the carriers are generated in the area not blocked by the grid line and transmitted to the busbar line through the electrode. In order to ensure the transmission efficiency of current collection, the width of the busbar line is large, which often causes a certain degree of shielding on the surface of the cell, so that the carriers generated in the blocked area cannot be effectively collected, resulting in a decrease in photoelectric conversion efficiency. Summary of the invention

[0004] The present invention provides a solar cell, a cell assembly and a photovoltaic system, aiming to solve the problem that the traditional arrangement method affects the photoelectric conversion efficiency.

[0005] The present invention is implemented as follows: a solar cell includes a silicon substrate and an electrode disposed on the silicon substrate, wherein the electrode includes a busbar line; The silicon substrate comprises a doping layer; The busbar line comprises: a connecting conductor and a thin busbar line; The connecting conductor extends along a first direction, and the fine gate line is arranged on a surface of the connecting conductor facing the silicon substrate; The connecting conductor is not in physical contact with the doping layer, and the fine gate line is in physical contact with the doping layer.

[0006] Optionally, the fine gate lines extend along the first direction.

[0007] Optionally, a plurality of the fine gate lines are provided and spaced apart along the first direction.

[0008] Optionally, along the first direction, the fine grid lines are collinear.

[0009] Optionally, along the first direction, at least some of the fine grid lines are staggered.

[0010] Optionally, along the first direction, at least one of the thin gate lines is equidistant from edges of the connecting conductors on both sides.

[0011] Optionally, along the first direction, distances between at least one of the thin gate lines and edges of the connecting conductors on both sides are unequal.

[0012] Optionally, along the first direction, distances between adjacent fine grid lines are equal.

[0013] Optionally, along the first direction, distances between at least some adjacent fine grid lines are unequal.

[0014] Optionally, along the first direction, the total length of the thin gate lines is 10% to 90% of the total length of the connecting conductor.

[0015] Optionally, along the first direction, the total length of the thin gate lines is 50% to 90% of the total length of the connecting conductor.

[0016] Optionally, it also includes a current collecting wire; The current collecting wire is arranged on the silicon substrate and extends along a second direction, and the second direction intersects with the first direction; At least one end of the connection conductor is connected to the current collecting wire, and the current collecting wire is not in physical contact with the doping layer.

[0017] Optionally, the current collecting wire comprises an edge bus line, and the edge bus line is arranged at an edge position of the silicon substrate.

[0018] Optionally, the silicon substrate has a light-facing surface and a backlight surface that are arranged opposite to each other, and the first region and the second region are alternately arranged along the second direction on the backlight surface, and the polarities of the first region and the second region are different; The bus bar lines include a first bus bar line disposed in the first region and a second bus bar line disposed in the second region.

[0019] Optionally, the doping layer includes a first doping layer and a second doping layer, the first doping layer is arranged in the first region, and the second doping layer is arranged in the second region; The thin gate line of the first bus gate line is in physical contact with the first doping layer; The thin gate line of the second bus gate line is in physical contact with the second doping layer.

[0020] Optionally, the backlight surface has a first edge and a second edge opposite to each other in the first direction, the backlight surface has a plurality of first series connection areas and a plurality of second series connection areas, the first series connection areas include a first edge series connection area closest to the first edge, and there is no second series connection area between the first edge series connection area and the first edge; The electrodes include a plurality of first electrodes and a plurality of second electrodes, all of the first electrodes and all of the second electrodes are arranged to cross the first series connection area and the second series connection area, the plurality of first electrodes include a plurality of first collecting gate lines and at least one first bus gate line, the first collecting gate line is discontinuous at the first edge series connection area and continuous at the second series connection area, the first bus gate line is continuous at both the first edge series connection area and the second series connection area, and the second electrodes are continuous at the first edge series connection area; The edge bus line includes a first edge bus line, the first edge bus line is closer to the first edge than the first edge series connection area, the first edge bus line is electrically connected to at least part of the first collecting grid line and is electrically connected to the first bus grid line; The solar cell also includes: a first auxiliary connecting line arranged in the first edge series area, in the second direction, the first auxiliary connecting line is provided on at least one side of the first bus bar line, the first auxiliary connecting line connects at least two of the second electrodes located on the same side of the first bus bar line, wherein the at least two second electrodes connected to the first auxiliary connecting line include the second electrode adjacent to the first bus bar line.

[0021] Optionally, the first edge bus line is electrically connected to all the first collecting gate lines; or The first edge bus line is electrically connected to a portion of the first collecting gate lines, and the number of the first collecting gate lines that are not electrically connected to the first edge bus line is less than or equal to four.

[0022] Optionally, the width of the first bus gate line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

[0023] Optionally, the width of the first edge bus line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

[0024] Optionally, a width of the first auxiliary connection line is greater than a width of a portion of the first collecting gate line located outside the second series connection region.

[0025] Optionally, several second series connection areas include a second edge series connection area closest to the first edge, the first electrode is continuous at the second edge series connection area, and the second electrode is discontinuous at the second edge series connection area. The solar cell also includes a second auxiliary connecting line, and the second auxiliary connecting line is arranged in the second edge series connection area. In the second direction, the second auxiliary connecting line connects the first bus grid line and at least one first collecting grid line located on one side of the first bus grid line.

[0026] Optionally, a width of the second auxiliary connection line is greater than a width of a portion of the first collecting gate line located outside the second series connection region.

[0027] Optionally, the plurality of second serial connection areas include a third edge serial connection area closest to the second edge, and there is no first serial connection area between the third edge serial connection area and the second edge; The plurality of second electrodes include a plurality of second collecting grid lines and at least one second bus grid line, the second collecting grid lines are discontinuous at the third edge series connection area and continuous at the first series connection area, the second bus grid lines are continuous at the third edge series connection area and the first series connection area, and the first electrodes are continuous at the third edge series connection area; The edge bus line further includes a second edge bus line, the second edge bus line is closer to the second edge than the third edge series connection area, the second edge bus line is electrically connected to at least a portion of the second collecting grid line and is electrically connected to the second bus grid line; The solar cell also includes: a third auxiliary connecting line arranged in the third edge series area, and in the second direction, the third auxiliary connecting line is provided on at least one side of the second bus bar line, and the third auxiliary connecting line connects at least two of the first electrodes located on the same side of the second bus bar line, wherein the at least two first electrodes connected to the third auxiliary connecting line include the first electrode adjacent to the second bus bar line.

[0028] Optionally, the second edge bus line is electrically connected to all the second collecting gate lines; or The second edge bus line is electrically connected to a portion of the second collecting gate lines, and the number of the second collecting gate lines that are not electrically connected to the second edge bus line is less than or equal to four.

[0029] Optionally, the width of the second bus gate line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

[0030] Optionally, the width of the second edge bus line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

[0031] Optionally, a width of the third auxiliary connection line is greater than a width of a portion of the second collecting gate line located outside the first series connection region.

[0032] Optionally, several of the first series connection areas include a fourth edge series connection area closest to the second edge, the second electrode is continuous at the fourth edge series connection area, and the first electrode is discontinuous at the fourth edge series connection area, and the solar cell also includes a fourth auxiliary connecting line, and the fourth auxiliary connecting line is arranged in the fourth edge series connection area, and in the second direction, the fourth auxiliary connecting line connects at least one of the second bus grid lines and at least one of the second collection grid lines located on one side of the second bus grid line.

[0033] Optionally, a width of the fourth auxiliary connection line is greater than a width of a portion of the second collecting gate line located outside the first series connection region.

[0034] The present invention also provides a battery assembly, comprising the above-mentioned solar cell.

[0035] The present invention also provides a photovoltaic system, comprising the above-mentioned battery assembly.

[0036] The beneficial effect achieved by the present invention is that the busbar line is arranged on the silicon substrate, the busbar line includes a connecting conductor and a fine grid line, the fine grid line is arranged on the surface of the connecting conductor facing the silicon substrate, the connecting conductor is not in physical contact with the doped layer, and the fine grid line is in physical contact with the doped layer. The fine grid line collects carriers generated by the silicon substrate, reduces carrier losses caused by shielding by the connecting conductor, and improves photoelectric conversion efficiency. The connecting conductor is used to transmit the collected carriers, and the transmission efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the backlight surface portion of the solar cell provided by the present invention; Figure 2 It is a partial enlarged schematic diagram of the backlight surface of the solar cell provided by the present invention; Figure 3 It is another partial enlarged structural schematic diagram of the backlight surface of the solar cell provided by the present invention; Figure 4 It is a schematic diagram of the busbar structure provided by the present invention.

[0038] Description of reference numerals: 100, solar cell; 10, silicon substrate; 101, first edge; 102, second edge; 11, first series connection area; 111, first edge series connection area; 112, fourth edge series connection area; 12, second series connection area; 121, second edge series connection area; 122, third edge series connection area; 20, first electrode; 21, first collecting grid line; 22, first bus grid line; 201, first welding section; 30, second electrode; 31, second collecting grid line; 32, second bus grid line; 301, second welding section; 40, first edge bus line; 50, second edge bus line; 60, first auxiliary connection line; 70, second auxiliary connection line; 80, third auxiliary connection line; 90, fourth auxiliary connection line; 200, bus bar line; 210, connecting conductor; 220, fine bar line. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0045] The present invention arranges a busbar line on a silicon substrate, wherein the busbar line includes a connecting conductor and a fine grid line, wherein the fine grid line is arranged on a surface of the connecting conductor facing the silicon substrate, the connecting conductor is not in physical contact with the doped layer, and the fine grid line is in physical contact with the doped layer. The fine grid line collects carriers generated by the silicon substrate, reduces carrier losses caused by shielding by the connecting conductor, and improves photoelectric conversion efficiency. The connecting conductor is used to transmit the collected carriers, and the transmission efficiency is high.

[0046] Embodiment 1 like Figure 1 and Figure 4 As shown, this embodiment provides a solar cell 100, comprising: a silicon substrate 10 and an electrode disposed on the silicon substrate 10, wherein the electrode comprises a busbar line 200; A silicon substrate 10 including a doped layer; The busbar line 200 includes: a connecting conductor 210 and a thin grid line 220; The connecting conductor 210 extends along a first direction, and the fine gate line 220 is arranged on a surface of the connecting conductor 210 facing the silicon substrate 10; The connection conductor 210 is not in physical contact with the doped layer, and the fine gate line 220 is in physical contact with the doped layer.

[0047] The silicon substrate 10 is the basis of the solar cell 100, and generally includes a silicon substrate and various functional layers stacked on the silicon substrate, that is, the silicon substrate 10 is the other part of the solar cell 100 except for the metallized electrode pattern. The functional layer includes a doping layer, and the doping layer includes a p-type doping layer and an n-type doping layer. The p-type doping layer and the n-type doping layer can be arranged on one side or both sides of the silicon substrate to form a pn junction to generate a photovoltaic effect. When light shines on the solar cell 100, photons can excite electrons to jump from the valence band to the conduction band to form electron-hole pairs. These carriers are separated at the pn junction due to the electric field to generate current.

[0048] An electrode is arranged on the silicon substrate 10, and the electrode is used to collect carriers (electrons or holes) generated by the silicon substrate. The electrode includes a busbar line 200. The busbar line 200 includes a connecting conductor 210 and a fine grid line 220, wherein the connecting conductor 210 maintains non-physical contact with the doped layer, and specifically, an insulating medium can be arranged at the non-physical contact position. The connecting conductor 210 is arranged on the silicon substrate 10, and the connecting conductor 210 has a surface facing the silicon substrate 10, and the fine grid line 220 is arranged on the surface of the connecting conductor 210 facing the silicon substrate 10, and the fine grid line 220 is in physical contact with the doped layer to collect the carriers generated by the silicon substrate 10. Since the connecting conductor 210 and the fine grid line 220 are both conductors, the two are electrically connected, and the connecting conductor 210 can lead out the carriers collected by the fine grid line 220. The connecting conductor 210 extends along a first direction, and different conductor structures can be connected at both ends of the extending direction of the connecting conductor 210.

[0049] It can be understood that physical contact refers to direct material contact between two or more objects, when the surfaces of two or more objects are in direct contact. When physical contact occurs between conductors, the circuit is connected. Non-physical contact means that there is no direct material contact between objects, and there is a gap between the objects, but it does not exclude that the objects act through some physical field or medium, such as connecting two separated conductors through other dielectrics.

[0050] In this embodiment, the busbar line 200 is arranged on the silicon substrate 10, and the busbar line 200 includes a connecting conductor 210 and a fine grid line 220. The fine grid line 220 is arranged on the surface of the connecting conductor 210 facing the silicon substrate 10. The connecting conductor 210 is not in physical contact with the doped layer, and the fine grid line 220 is in physical contact with the doped layer. The fine grid line 220 collects carriers generated by the silicon substrate, reduces carrier losses caused by shielding by the connecting conductor 210, and improves the photoelectric conversion efficiency. The connecting conductor 210 is used to transmit the collected carriers, and the transmission efficiency is high.

[0051] Embodiment 2 like Figure 4 As shown, in some embodiments, the fine gate lines 220 extend along a first direction.

[0052] Specifically, one or more thin gate lines 220 may be provided. When multiple thin gate lines 220 are provided, the multiple thin gate lines 220 may be arranged in parallel, the projections of the multiple thin gate lines 220 along the first direction may partially overlap, or the projections of the multiple thin gate lines 220 along the first direction may be spaced apart from each other.

[0053] The connecting conductor 210 extends along the first direction, and the extending direction of the thin grid line 220 is consistent with the extending direction of the connecting conductor 210. This arrangement helps to uniformly transmit the current, reduce the local resistance inside the battery, and improve the overall current collection efficiency.

[0054] In some embodiments, along the first direction, at least one thin gate line 220 is equidistant from edges of the connecting conductors 210 on both sides.

[0055] That is, along the first direction, at least one fine grid line 220 is placed at the center of the connecting conductor 210, and at least one fine grid line 220 overlaps with the center line position of the connecting conductor 210. At the center, the distances between the fine grid line 220 and the edges of the connecting conductor 210 on both sides are equal, ensuring that the fine grid line 220 is evenly distributed on the connecting conductor 210 to avoid local overheating. At the same time, the fine grid line 220 is placed at the center of the connecting conductor 210, which can simplify the design and manufacturing process and improve production efficiency.

[0056] In some embodiments, along the first direction, the distances between at least one thin gate line 220 and the edges of the connecting conductors 210 on both sides are different.

[0057] That is, at least one fine grid line 220 is set at a position that does not overlap with the center line of the connecting conductor 210, and the fine grid line 220 is set at a position deviating from the center line of the connecting conductor 210 and at a certain distance from the center line. The distribution position of the fine grid line 220 can be optimized according to the requirements of light intensity and battery design, so that the fine grid line 220 can better collect carriers.

[0058] Embodiment 3 In some embodiments, a plurality of fine gate lines 220 are provided and spaced apart along the first direction.

[0059] There are more than two fine grid lines 220, and along the first direction, there is a certain distance between any two adjacent fine grid lines 220, that is, the projections of any two fine grid lines 220 in the first direction do not overlap. It can be understood that a coordinate axis x is established along the first direction, and the projection of the fine grid line 220 on the coordinate axis x is the projection of the fine grid line 220 in the first direction.

[0060] The fine grid lines 220 are arranged at intervals along the first direction, and can collect carriers well along the extension direction of the first direction, while the fine grid lines 220 are not arranged at the interval positions. At the contact position between the fine grid lines 220 and the connecting conductor 210, the carriers will be captured and recombined, resulting in recombination losses. The fine grid lines 220 are arranged at intervals along the first direction, which reduces the contact area between the fine grid lines 220 and the connecting conductor 210, and can reduce the carrier recombination losses caused by slurry recombination. At the same time, the fine grid lines 220 do not need to be arranged at the interval positions, and the use of slurry during manufacturing can also be saved, thereby reducing the production cost of the solar cell 100.

[0061] In some embodiments, along the first direction, the fine gate lines 220 are collinear.

[0062] That is, the multiple fine grid lines 220 are distributed along the same straight line, and the distances between any two adjacent fine grid lines can be all equal, partially equal, or all unequal, which is not limited here. The collinear arrangement can collect carriers in a concentrated manner and reduce the influence of dispersion on battery performance. At the same time, the collinear arrangement of fine grid lines 220 can simplify the design and manufacturing process and improve production efficiency.

[0063] In some embodiments, the fine gate lines 220 are staggered along the first direction.

[0064] A plurality of fine gate lines 220 are provided, and at least some of the fine gate lines 220 are not distributed along the same straight line. Specifically, all the fine gate lines 220 may not be distributed along the same straight line, that is, all the fine gate lines 220 are not collinear. For example, four fine gate lines 220 are provided, wherein the spacing between any two fine gate lines 220 along the direction perpendicular to the first direction is not 0. It may also be that some of the fine gate lines 220 are distributed along the same straight line, and some of the fine gate lines 220 are not distributed along the same straight line. For example, four fine gate lines 220 are provided, wherein three of the fine gate lines 220 are distributed along the same straight line, and the spacing between one fine gate line 220 and the three collinear fine gate lines 220 along the direction perpendicular to the first direction is not 0.

[0065] In some embodiments, along the first direction, distances between adjacent fine gate lines 220 are equal.

[0066] The distance between the two adjacent ends of two adjacent fine gate lines 220 is the distance between the two fine gate lines 220. The equal spacing ensures that the fine gate lines 220 are evenly distributed on the connecting conductor 210, thereby improving the uniformity of carrier collection.

[0067] In some embodiments, along the first direction, distances between at least some adjacent fine gate lines 220 are unequal.

[0068] The distances between all the fine gate lines 220 may be unequal. For example, four fine gate lines 220 are provided, and the distance between the first fine gate line 220 and the second fine gate line 220 is 50 μm, the distance between the second fine gate line 220 and the third fine gate line 220 is 60 μm, and the distance between the third fine gate line 220 and the fourth fine gate line 220 is 70 μm. Alternatively, the distances between some adjacent fine gate lines 220 are equal, and the distances between some adjacent fine gate lines 220 are unequal. For example, the distance between the first fine gate line 220 and the second fine gate line 220 is 50 μm, the distance between the second fine gate line 220 and the third fine gate line 220 is 50 μm, and the distance between the third fine gate line 220 and the fourth fine gate line 220 is 70 μm.

[0069] The design of unequal spacing can optimize the distribution of the fine grid lines 220 according to the requirements of light intensity and battery design, so that the fine grid lines 220 can better collect carriers.

[0070] Embodiment 4 In some embodiments, along the first direction, the total length of the thin gate line 220 is 10% to 90% of the total length of the connecting conductor 210 .

[0071] The connecting conductor 210 extends along the first direction, and the total length of the connecting conductor 210 along the first direction is the distance between the two ends of the connecting conductor 210. The total length of the fine grid lines 220 along the first direction is the projection length of the fine grid lines 220 in the first direction. It can be understood that when multiple fine grid lines 220 are provided, if the projections of multiple fine grid lines 220 in the first direction overlap, the length of the overlapping portion is only calculated once.

[0072] The total length of the thin grid line 220 is 10% to 90% of the total length of the connecting conductor 210. Specifically, the ratio of the total length of the thin grid line 220 to the total length of the connecting conductor 210 can be 10%, 15%, 20%, 30%, 40%, 45%, 50%, 60%, 65%, 70%, 80%, 85%, 90%, or other ratios between 10% and 90%, which are not limited here. Exemplarily, assuming that the total length of the connecting conductor 210 is 10 mm, the total length of the thin grid line 220 can be 1 mm to 9 mm.

[0073] The total length of the fine grid lines 220 is 10% to 90% of the total length of the connecting conductor 210, which ensures that the fine grid lines 220 can effectively transmit current and reduce the contact area between the fine grid lines 220 and the connecting conductor 210, which can reduce the carrier recombination loss caused by the slurry recombination, and at the same time, reduce the use of the slurry of the fine grid lines 220, saving production costs. By reasonably designing the length of the fine grid lines 220, damage caused by excessive accumulation of materials can be avoided, and the long-term reliability of the battery can be improved.

[0074] In some embodiments, along the first direction, the total length of the thin gate line 220 is 50% to 90% of the total length of the connecting conductor 210 .

[0075] The total length of the fine grid lines 220 along the first direction is 50% to 90% of the total length of the connecting conductor 210. For example, assuming that the total length of the connecting conductor 210 is 10 mm, the total length of the fine grid lines 220 can be 5 mm to 9 mm. A higher length ratio of the fine grid lines 220 can maximize the collection efficiency of carriers and improve the photoelectric conversion efficiency of the battery. Compared with full-length coverage, this method can reduce the amount of slurry used and reduce costs.

[0076] Embodiment 5 In some embodiments, the solar cell further comprises a current collecting wire; The current collecting wire is arranged on the silicon substrate 10 and extends along a second direction, and the second direction intersects with the first direction; At least one end of the connection conductor 210 is connected to a collector wire, and the collector wire is not in physical contact with the doping layer.

[0077] The connecting conductor 210 extends along a first direction, and the collecting wire extends along a second direction, and the second direction intersects the first direction. Specifically, the collecting wire may extend along the longitudinal direction of the silicon substrate 10, and the connecting conductor 210 may extend along the transverse direction of the silicon substrate 10, that is, the first direction may be the longitudinal direction of the solar cell 100, and the second direction may be the transverse direction of the solar cell 100, and the two directions are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, for example, the two directions may be the diagonal directions of the silicon substrate 10, respectively, and are not specifically limited here.

[0078] The collector wire is made of a conductive material and is not in physical contact with the doped layer, that is, the collector wire is spaced from the doped layer in space, and specifically, an insulating medium may be provided between the collector wire and the doped layer. It can be understood that since the fine grid line 220 is in physical contact with the doped layer and is mutually conductive, and the connecting conductor 210 is connected to both the fine grid line 220 and the collector wire, the collector wire may be indirectly conductive with the doped layer through the bus grid line 200.

[0079] The collector wire is used to transfer carriers, and at least one end of the connecting conductor 210 is connected to the collector wire, and the carriers collected by the fine grid line 220 are transferred to the collector wire through the connecting conductor 210. The other end of the connecting conductor 210 can be connected to the collector wire, or to other conductive structures, such as a pad point, other connecting wires, etc., which are not limited here.

[0080] In some embodiments, the current collecting wires include edge bus lines, and the edge bus lines are disposed at the edge of the silicon substrate 10 .

[0081] The edge bus bar is arranged at the edge position of the silicon substrate 10, and the "edge position" refers to the peripheral area of ​​the silicon substrate 10, that is, the outermost part of the planar layout of the silicon substrate 10. Usually, an edge bus bar can connect a number of electrodes (including collecting grid lines and bus grid lines 200) to transmit the current on the electrodes. It can be understood that since the edge bus bar is used to transmit current, the current transmission efficiency is related to the cross-sectional area of ​​the transmission carrier. The larger the cross-sectional area, the smaller the resistance during the current transmission process. Therefore, the edge bus bar usually has a wider cross-sectional area. In order to avoid the uneven surface of the solar cell, the thickness of the edge bus bar is thinner, and the edge bus bar will have a wider width.

[0082] If the edge bus bar is set in the middle of the cell or other parts of the surface, it will block the effective light absorption area, reduce the generation of photogenerated carriers (i.e. photogenerated electrons and holes), and thus reduce the photoelectric conversion efficiency of the cell. Setting the edge bus bar at the edge can minimize the blockage of the effective light absorption area and improve the overall efficiency of the cell.

[0083] Embodiment 6 In some embodiments, the silicon substrate 10 has a light-facing surface and a backlight surface that are oppositely disposed, and the first region and the second region are alternately disposed along the second direction on the backlight surface, and the polarities of the first region and the second region are different; The bus gate lines 200 include a first bus gate line 22 disposed in a first region and a second bus gate line 32 disposed in a second region.

[0084] The silicon substrate 10 has a light-facing surface and a backlight surface that are arranged opposite to each other. The light-facing surface generally refers to the side of the solar cell that receives sunlight radiation, and the backlight surface refers to the side of the solar cell that is away from sunlight radiation. The two surfaces are arranged opposite to each other.

[0085] Specifically, the silicon substrate 10 includes a silicon substrate and a doping layer, and the doping layer is arranged on the silicon substrate. The doping layer includes a first doping layer and a second doping layer. The first doping layer is arranged in the first region, and the second doping layer is arranged in the second region. The first region and the second region are arranged alternately along the first direction, that is, the first doping layer and the second doping layer are alternately arranged along the first direction on the silicon substrate. The first doping layer and the second doping layer have different polarities, and the first doping layer may be a P-type doping layer and the second doping layer may be an N-type doping layer, or the first doping layer may be an N-type doping layer and the second doping layer may be a P-type doping layer. The first polarity doping layer and the second polarity doping layer form regions with different electrical characteristics, supporting the formation of PN junctions and the separation of carriers.

[0086] The busbar line 200 includes a first busbar line 22 and a second busbar line 32. The first busbar line 22 is arranged in the first region. The fine grid line 220 on the first busbar line 22 is in ohmic contact with the first doping layer, collects the carriers generated in the corresponding first region, and transmits and connects the carriers generated in other first regions. The second busbar line 32 is arranged in the second region. The fine grid line 220 on the second busbar line 32 is in ohmic contact with the second doping layer, collects the carriers generated in the corresponding second region, and transmits and connects the carriers generated in other second regions.

[0087] It can be understood that the first area and the second area are arranged alternately, that is, the first area and the second area are arranged on the same piece of the silicon substrate 10, usually, they are arranged on the backlight surface of the silicon substrate 10. The first electrode 20 and the second electrode 30 are arranged corresponding to the first area and the second area respectively, and the first electrode 20 and the second electrode 30 are arranged on the backlight surface of the silicon substrate 10. The light-facing surface of the silicon substrate 10 is not blocked by electrodes, so the light absorption area can be maximized, the shadow loss can be reduced, and the photoelectric conversion efficiency of the battery can be significantly improved.

[0088] The first electrode 20 is arranged in the first region, in ohmic contact with the first doped layer, and collects carriers generated in the first region. The second electrode 30 is arranged in the second region, in ohmic contact with the second doped layer, and collects carriers generated in the second region. Alternating the first region and the second region can ensure uniform distribution of the fine gate lines 220 on the silicon substrate 10, and improve the uniformity of carrier collection.

[0089] Embodiment 7 like Figures 1 to 3 As shown, in some embodiments, the backlight surface has a first edge 101 and a second edge 102 opposite to each other in the first direction, the backlight surface has a plurality of first series connection areas 11 and a plurality of second series connection areas 12, the first series connection area 11 includes a first edge series connection area 111 closest to the first edge, and there is no second series connection area 12 between the first edge series connection area 111 and the first edge 101; The electrodes include a plurality of first electrodes 20 and a plurality of second electrodes 30, all of the first electrodes 20 and all of the second electrodes 30 are arranged crosswise with the first series connection area 11 and the second series connection area 12, the plurality of first electrodes 20 include a plurality of first collecting grid lines 21 and at least one first bus grid line 22, the first collecting grid line 21 is discontinuous at the first edge series connection area 111 and continuous at the second series connection area 12, the first bus grid line 22 is continuous at the first edge series connection area 111 and the second series connection area 12, and the second electrodes 30 are continuous at the first edge series connection area 111; The edge bus line includes a first edge bus line 40 . The first edge bus line 40 is closer to the first edge 101 than the first edge series connection area 111 . The first edge bus line 40 is electrically connected to at least a portion of the first collector grid line 21 and to the first bus grid line 22 . The solar cell also includes: a first auxiliary connecting line 60 arranged in the first edge series connection area 111, and in the second direction, the first auxiliary connecting line 60 is provided on at least one side of the first bus bar line 22, and the first auxiliary connecting line 60 connects at least two second electrodes 30 located on the same side of the first bus bar line 22, wherein the at least two second electrodes 30 connected to the first auxiliary connecting line 60 include a second electrode 30 adjacent to the first bus bar line 22.

[0090] The solar cell 100 in the embodiment of the present application may include a silicon substrate 10 , a plurality of first electrodes 20 , a plurality of second electrodes 30 , a first edge bus bar 40 , a first insulating layer (not shown in the figure) and a first auxiliary connection line 60 .

[0091] The silicon substrate 10 has a light-facing surface and a backlight surface opposite to each other. The backlight surface of the silicon substrate 10 has a first edge 101 and a second edge 102 opposite to each other in a first direction. The backlight surface has a plurality of first series connection areas 11 and a plurality of second series connection areas 12. The first series connection areas 11 and the second series connection areas 12 are used to set positive electrode welding strips and negative electrode welding strips, respectively. In other words, one of the first series connection areas 11 and the second series connection areas 12 is a positive electrode series connection area, and the other is a negative electrode welding area.

[0092] like Figure 1 and Figure 3 As shown, in the first direction, the first serial connection areas 11 and the second serial connection areas 12 are arranged alternately, and the first serial connection areas 11 include a first edge serial connection area 111 closest to the first edge 101, and there is no second serial connection area 12 between the first edge serial connection area 111 and the first edge 101. In other words, Figure 1 As shown, in the first series connection area 11 and the second series connection area 12 , the series connection area closest to the first edge 101 is the first series connection area 11 , and the first series connection area 11 is represented as a first edge series connection area 111 , and there is no other series connection area between the first edge series connection area 111 and the first edge 101 .

[0093] like Figure 1 As shown, a plurality of first electrodes 20 and a plurality of second electrodes 30 are alternately arranged on the backlight surface along the second direction, and the second direction intersects with the first direction. All the first electrodes 20 and all the second electrodes 30 are arranged to intersect with the first series connection area 11 and the second series connection area 12, that is, the first series connection area 11 and the second series connection area 12 extend along the second direction to intersect with the first electrodes 20 and the second electrodes 30.

[0094] In some embodiments, the first direction and the second direction may be the longitudinal direction and the lateral direction of the solar cell 100, respectively, and the two directions are perpendicular to each other. Figure 1 In the example shown, the first direction is the lateral direction of the solar cell 100, and the second direction is the longitudinal direction of the solar cell 100. Of course, in other embodiments, the first direction and the second direction may also be other directions, such as two diagonal directions of the solar cell 100, which are not specifically limited here.

[0095] The first electrodes 20 may include a plurality of first collecting gate lines 21 and at least one first bus gate line 22. The first collecting gate lines 21 are discontinuous at the first edge series connection area 111 and continuous at the second series connection area 12. The first bus gate lines 22 are continuous at both the first edge series connection area 111 and the second series connection area 12. The second electrodes 30 are continuous at the first edge series connection area 111.

[0096] That is, the first electrode 20 includes at least two types of gate lines, one is the first collecting gate line 21, and the other is the first bus gate line 22. The first collecting gate line 21 is discontinuous at the first edge series connection area 111, and the first bus gate line 22 is continuous at the first edge series connection area 111. The second electrode 30 is also continuous at the first edge series connection area 111. In the battery assembly, the welding strip in the first series connection area 11 (including the first edge series connection area 111) is used to connect with the second electrode 30 to realize the bus output of the second electrode 30, and the welding strip in the second series connection area 12 is used to be welded and connected with the first electrode 20 to realize the bus output of the first electrode 20.

[0097] like Figure 2 As shown, the first edge bus line 40 is closer to the first edge 101 than the first edge series connection area 111, and the first edge bus line 40 is electrically connected to at least part of the first collection grid line 21 and to the first bus grid line 22. Specifically, in order to avoid welding at the edge position of the first edge 101 and causing hidden cracks in the battery, the first edge bus line 40 is not used for welding, and is used to collect the current of the first collection grid line 21 located between the first edge series connection area 111 and the first edge 101, and then converge to the second series connection area 12 (i.e., the second series connection area 12) adjacent to the first edge series connection area 111 through the first bus grid line 22. Figure 1 and Figure 2 The solar cell 100 is connected to a solder strip of the same polarity in the second series connection area 12 on the leftmost side of the solar cell 100, thereby collecting the current of the electrode in the edge area of ​​the first electrode 20 located at the first edge 101, thereby improving the efficiency of the solar cell 100. If the first edge bus line 40 and the first bus grid line 22 are not provided, the portion of the first electrode 20 located between the first edge series connection area 111 and the first edge 101 will form an isolated electrode, resulting in the inability to collect the current of this portion.

[0098] The first auxiliary connection line 60 is disposed in the first edge series connection area 111. In the second direction, at least one side of the first busbar line 22 is provided with the first auxiliary connection line 60. The first auxiliary connection line 60 connects at least two second electrodes 30 located on the same side of the first busbar line 22. Figure 2 As shown, in some embodiments, the at least two second electrodes 30 connected to the first auxiliary connection line 60 preferably include the second electrode 30 adjacent to the first bus bar line 22 (ie Figure 1 and Figure 2 In other words, in some embodiments, the first auxiliary connection line 60 is preferably connected to the second electrode 30 closest to the first bus grid line 22, and the first auxiliary connection line 60 is also connected to at least one of the remaining second electrodes 30 located on the same side as the second electrode 30. In other words, the first auxiliary connection line 60 is preferably connected to at least the second electrode 30 adjacent to the first bus grid line 22 and at least one of the remaining second electrodes 30 on the same side.

[0099] In the solar cell 100 , the first electrode 20 corresponds to the first doped layer one by one, and the second electrode 30 corresponds to the second doped layer one by one. One of the first doped layer and the second doped layer may be a P-type doped layer, and the other may be an N-type doped layer.

[0100] In some embodiments, the solar cell 100 is a busbarless solar cell. In some first electrodes 20, the first collection grid line 21 is disconnected at the first series connection area 11 and is continuous at the second series connection area 12, the first bus grid line 22 is continuous at the first edge series connection area 111 and is disconnected at the remaining first series connection areas 11, and is continuous at the second series connection area 12.

[0101] In some embodiments, the first electrode 20 may include a first welding segment 201 corresponding to the second series connection region 12, and the second electrode 30 may include a second welding segment 301 corresponding to the first edge series connection region 111. The first welding segment 201 and the second welding segment 301 are used for welding with the welding strip.

[0102] In some embodiments, the width of the first busbar line 22 (i.e., the length in the second direction) may be greater than the width of the portion of the first collecting gate line 21 located outside the second series connection area 12 (i.e., the portion of the first collecting gate line 21 except the first welding section 201).

[0103] Thus, since the first bus grid lines 22 need to bear the function of current collection and transmission, setting the width of the first bus grid lines 22 to be wider can reduce the transmission loss in the current collection process and improve the efficiency.

[0104] In addition, if Figure 1 and Figure 2As shown, in the embodiment of the present application, in the first bus grid line 22, it is continuous only at the first edge series connection area 111, and is disconnected at the other first series connection areas 11. At the same time, the first bus grid line 22 is continuous at the second series connection area 12 and has a first welding section 201 at the second series connection area 12. Only the section of the first bus grid line 22 closest to the first edge 101 has the bus function. Therefore, in some embodiments, in order to save slurry and reduce costs, only this part of the grid line segment can be set to be wider. In this case, please refer to Figure 1 and Figure 2 , the plurality of second series connection regions 12 may include a second edge series connection region 121 closest to the first edge 101. The first busbar line 22 may include a first busbar segment located between the second edge series connection region 121 and the first edge 101. In some embodiments, the width of the first busbar segment (i.e., the length in the second direction) may be greater than the width of the remaining portion of the first busbar line 22 located outside the second series connection region 12 (i.e., the portion other than the first welding segment 201 of the portion other than the first busbar segment).

[0105] In this way, only by setting the width of the first bus section to be wider, the use of slurry can be reduced while reducing bus transmission loss, thereby reducing costs.

[0106] See also Figure 2 In some embodiments, the width (length in the first direction) of the first edge bus line 40 is greater than the width (length in the second direction) of the portion of the first collecting gate line 21 outside the second series connection area 12 (i.e., the portion of the first collecting gate line 21 except the first welding section 201).

[0107] Thus, since the first edge bus line 40 needs to bear the function of current collection and transmission, setting the width of the first edge bus line 40 to be wider can also reduce the transmission loss in the current collection process and improve the efficiency.

[0108] Also, please read Figure 2 In some embodiments, the width (length in the first direction) of the first auxiliary connection line 60 is greater than the width (length in the second direction) of the portion of the first collection gate line 21 located outside the second series connection area 12 (i.e., the portion of the first collection gate line 21 except the first welding section 201).

[0109] Thus, since the first auxiliary connection line 60 plays the role of transmitting and converging current when cold soldering occurs, setting the width of the first auxiliary connection line 60 wider can also reduce transmission loss during the converging process and improve efficiency.

[0110] In some embodiments, the width of the first auxiliary connection line 60 may be the same as the width of the first edge bus line 40 .

[0111] In addition, if Figure 1 and Figure 2 As shown, in some embodiments, in the solar cell 100, a chamfer is formed at the intersection of the first edge 101 and the adjacent edge, and the first electrode 20 is correspondingly arranged at the chamfer. Figure 1 and Figure 2 As shown, in order to achieve the connection between the first edge bus line 40 and the first electrode 20, the first edge bus line 40 has a bent portion at the chamfer. Of course, it can be understood that in some embodiments, if the solar cell 100 does not have a chamfer, there is no need to set a bent portion.

[0112] like Figure 1 and Figure 2 As shown, in some embodiments, the plurality of second series connection regions 12 include a second edge series connection region 121 closest to the first edge 101 (i.e., a second series connection region 12 adjacent to the first edge series connection region 111), the first electrode 20 is continuous at the second edge series connection region 121, and the second electrode 30 is discontinuous at the second edge series connection region 121, and the solar cell 100 further includes a second auxiliary connection line 70, which is disposed in the second edge series connection region 121, and in the second direction, the second auxiliary connection line 70 connects the first bus grid line 22 and at least one first collection grid line 21 located on one side of the first bus grid line 22.

[0113] Thus, by disposing the second auxiliary connection line 70 in the second edge series connection area 121 , it is possible to effectively avoid the phenomenon that the welding strip in the second edge series connection area 121 has a cold solder joint or poor contact at the first bus bar line 22 , resulting in the current transmitted from the first bus bar line 22 not being collected.

[0114] Specifically, Figure 2 As shown, in such an embodiment, the number of second auxiliary connecting lines 70 can be consistent with the number of first bus grid lines 22, and the two correspond one to one. When the first bus grid line 22 is located in the middle position (that is, there are first collecting grid lines 21 on both sides of the first bus grid line 22), the second auxiliary connecting line 70 connects the first bus grid line 22 and also connects two first collecting grid lines 21 adjacent to the first bus grid line 22 (that is, the first collecting grid lines 21 located on both sides of the first bus grid line 22 and adjacent to it).

[0115] In some embodiments, the width (length in the first direction) of the second auxiliary connection line 70 may be greater than the width (length in the second direction) of the portion of the first collecting grid line 21 outside the second series connection area 12 (i.e., the portion of the first collecting grid line 21 except the first welding section 201). In this way, since the second auxiliary connection line 70 plays the role of transmitting and converging current when a cold weld occurs at the first bus grid line 22, setting the width of the second auxiliary connection line 70 wider can also reduce transmission loss during the converging process and improve efficiency.

[0116] like Figure 1 and Figure 3 As shown, in some embodiments, the plurality of second serial connection areas 12 include a third edge serial connection area 122 closest to the second edge 102, and there is no first serial connection area 11 between the third edge serial connection area 122 and the second edge 102. Figure 1 and Figure 3 As shown, in the first series connection area 11 and the second series connection area 12 , the series connection area closest to the second edge 102 is the second series connection area 12 , and the second series connection area 12 is represented as a third edge series connection area 122 . There is no other series connection area between the third edge series connection area 122 and the second edge 102 .

[0117] The second electrodes 30 include a plurality of second collecting gate lines 31 and at least one second bus gate line 32 . The second collecting gate lines 31 are discontinuous at the third edge series connection area 122 and continuous at the first series connection area 11 . The second bus gate lines 32 are continuous at the third edge series connection area 122 . The first electrodes 20 are continuous at the second edge series connection area 121 .

[0118] That is, the second electrode 30 includes at least two types of gate lines, one is the second collecting gate line 31, and the other is the second bus gate line 32. The second collecting gate line 31 is interrupted at the third edge series area 122, and the second bus gate line 32 is continuous at the third edge series area 122. The first electrode 20 is also continuous at the third edge series area 122.

[0119] The solar cell 100 further includes a second edge bus line 50, a second insulating layer, and a third auxiliary connection line 80. The second edge bus line 50 is closer to the second edge 102 than the third edge series connection area 122, and the second edge bus line 50 is electrically connected to at least a portion of the second collection grid line 31 and the second bus grid line 32. Specifically, in order to avoid welding at the edge position of the second edge 102 and causing hidden cracks in the battery, the second edge bus line 50 is not used for welding, and is used to collect the current of the portion of the second collection grid line 31 located between the third edge series connection area 122 and the second edge 102, and then converges to the first series connection area 11 (i.e., the first series connection area 11) adjacent to the third edge series connection area 122 through the second bus grid line 32. Figure 1 and Figure 3 The same polarity welding strip in the first series connection area 11) on the rightmost side of the solar cell 100 is connected to collect the current of the electrode in the edge area of ​​the second electrode 30 located at the second edge 102, thereby improving the efficiency of the solar cell 100. If the second edge bus line 50 and the second bus grid line 32 are not provided, the portion of the second electrode 30 located between the third edge series connection area 122 and the second edge 102 will form an isolated electrode, resulting in the inability to collect the current of this portion.

[0120] The third auxiliary connection line 80 is disposed in the third edge series connection area 122. In the second direction, at least one side of the second bus grid line 32 is provided with the third auxiliary connection line 80, and the third auxiliary connection line 80 connects at least two first electrodes 20 located on the same side of the second bus grid line 32. In some embodiments, the at least two first electrodes 20 connected to the third auxiliary connection line 80 preferably include the first electrode 20 adjacent to the second bus grid line 32 (i.e. Figure 1 and Figure 3 In other words, in some embodiments, the third auxiliary connection line 80 is preferably connected to the first electrode 20 closest to the second bus grid line 32, and the third auxiliary connection line 80 is also connected to at least one of the remaining first electrodes 20 located on the same side as the second electrode 30. In other words, the third auxiliary connection line 80 is preferably connected to at least the first electrode 20 adjacent to the second bus grid line 32 and at least one of the remaining first electrodes 20 on the same side.

[0121] Thus, by setting the second edge bus line 50 and the second bus grid line 32, the current collected by the isolated electrode of at least part of the first electrode 20 located between the third edge series connection area 122 and the second edge 102 can be converged to the welding strip of the same polarity in the first series connection area 11 adjacent to the third edge series connection area 122, which can effectively avoid welding at the second edge 102 of the solar cell 100 and cause hidden cracks while ensuring the efficiency of the solar cell 100. At the same time, through the setting of the third auxiliary connection line 80, even if a cold weld occurs between the first electrode 20 and the welding strip near the second insulating layer due to the setting of the second insulating layer, due to the existence of the third auxiliary connection line 80, the first electrode 20 with a cold weld can also realize the current convergence output through the third auxiliary connection line 80, reducing the impact caused by the cold weld, thereby ensuring the efficiency of the solar cell 100.

[0122] like Figure 1 and Figure 3As shown, in some embodiments, the solar cell 100 is a main grid-less solar cell, and in some second electrodes 30, the second collecting grid line 31 is disconnected at the second series connection area 12 and is continuous at the first series connection area 11, the second collecting grid line 32 is continuous at the third edge series connection area 122 and is disconnected at the remaining second series connection areas 12, and is continuous at the first series connection area 11.

[0123] like Figure 1 and Figure 3 As shown, in the embodiment of the present application, in order to reduce the influence of cold solder joints as much as possible, when the first electrodes 20 are provided on both sides of the second bus bar line 32 , third auxiliary connection lines 80 are preferably provided on both sides of the second bus bar line 32 .

[0124] In some embodiments, the width of the second bus grid line 32 (i.e., the length in the second direction) may be greater than the width (i.e., the length in the second direction) of the portion of the second collecting grid line 31 located outside the first series connection area 11 (i.e., the portion of the second collecting grid line 31 except the second welding section 301).

[0125] Thus, since the second bus grid lines 32 need to bear the function of current collection and transmission, setting the width of the second bus grid lines 32 to be wider can reduce the transmission loss in the current collection process and improve the efficiency.

[0126] like Figure 3 As shown, in some embodiments, the width (length in the first direction) of the second edge bus line 50 is greater than the width (length in the second direction) of the portion of the second collecting gate line 31 located outside the first series connection area 11 (i.e., the portion of the second collecting gate line 31 except the second welding section 301).

[0127] Thus, since the second edge bus line 50 needs to bear the function of current collection and transmission, setting the width of the second edge bus line 50 to be wider can also reduce the transmission loss in the current collection process and improve the efficiency.

[0128] Specifically, in such an embodiment, the width of the second edge bus line 50 can be the same as the width of the second welding section 301. In this way, it can be ensured that no large bus loss will be caused during the bus process. At the same time, during printing, only the same size of screen slots need to be opened on the screen to print the three at the same time, which can effectively save manufacturing processes and reduce manufacturing difficulty.

[0129] In addition, if Figure 3 As shown, in some embodiments, the width (length in the first direction) of the third auxiliary connection line 80 is greater than the width (length in the second direction) of the portion of the second collection gate line 31 located outside the first series area 11 (i.e., the portion of the second collection gate line 31 except the second welding section 301).

[0130] Thus, since the third auxiliary connection line 80 plays the role of transmitting and converging current when cold soldering occurs, setting the width of the third auxiliary connection line 80 wider can also reduce transmission loss during the converging process and improve efficiency.

[0131] In some embodiments, the width of the third auxiliary connection line 80 may be the same as the width of the second edge bus line 50 .

[0132] like Figure 1 and Figure 3 As shown, in some embodiments, the second edge bus line 50 is electrically connected to all second collecting grid lines 31. In this way, the current collected by the isolated grid line segments between the third edge series connection area 122 and the second edge 102 in all second collecting grid lines 31 can be combined to maximize the efficiency of the solar cell 100.

[0133] Of course, in some embodiments, the second edge bus lines 50 may also be electrically connected to some of the second collecting grid lines 31. In this case, the number of the second collecting grid lines 31 that are not electrically connected to the second edge bus lines 50 is less than or equal to 4. In this way, even if some of the second collecting grid lines 31 are not connected to the second edge bus lines 50, the number is very small, and will not cause excessive efficiency loss and result in product defects.

[0134] In some embodiments, the third auxiliary connection line 80 connects 2-20 first electrodes 20. Thus, by setting the number of first electrodes 20 connected to the third auxiliary connection line 80 within this reasonable range, the influence of cold solder joints can be reduced as much as possible or even eliminated.

[0135] In the embodiment of the present application, the number of the second bus grid line 32 may be single. In this case, the third auxiliary connection line 80 may be provided only on one side of the second bus grid line 32, or may be provided on both sides of the second bus grid line 32, and the specific details are not limited here. When both sides of the second bus grid line 32 are provided with the first electrode 20, it is preferred to provide the third auxiliary connection line 80 on both sides.

[0136] In addition, it should be noted that, in the present application, when there are multiple second bus bars 32, the third auxiliary connection line 80 may be provided only on one side or both sides of some of the second bus bars 32, while the third auxiliary connection line 80 may not be provided on both sides of the remaining second bus bars 32. In this case, the problem of cold solder joints at some locations can also be solved. In the present application, it is preferred that the third auxiliary connection line 80 is provided on both sides of each second bus bar line 32.

[0137] Of course, if Figure 1and Figure 3 As shown, in some embodiments, the number of the second bus grid lines 32 may be multiple. Providing multiple second bus grid lines 32 can shorten the current collection path, effectively reduce the collection transmission loss, and improve efficiency.

[0138] In this case, a third auxiliary connection line 80 is disposed between two adjacent second bus gate lines 32 , and the third auxiliary connection line 80 between two adjacent second bus gate lines 32 connects all first electrodes 20 between two adjacent second bus gate lines 32 .

[0139] In this way, the third auxiliary connection line 80 is connected to all the first electrodes 20 between two adjacent second bus bars 32 , which can substantially completely eliminate the influence of cold solder joints and improve the efficiency of the solar cell 100 as much as possible.

[0140] Of course, in some less preferred embodiments, the third auxiliary connection line 80 may be disposed only on one side of the second bus bar line 32 , which is not specifically limited herein.

[0141] Specifically, in such an embodiment, the number of the second busbar lines 32 in the solar cell 100 can be selected according to the actual conditions such as the size of the solar cell and the loss during the transmission process, and is not limited here.

[0142] like Figure 1 and Figure 3 As shown, in some embodiments, the plurality of first series connection regions 11 may further include a fourth edge series connection region 112 closest to the second edge 102 (i.e., the first series connection region 11 adjacent to the third edge series connection region 122), the second electrode 30 is continuous at the fourth edge series connection region 112, and the first electrode 20 is discontinuous at the fourth edge series connection region 112, and the solar cell 100 may further include a fourth auxiliary connection line 90, which is disposed in the fourth edge series connection region 112, and in the second direction, the fourth auxiliary connection line 90 connects the second bus grid line 32 and at least one second collection grid line 31 located on one side of the second bus grid line 32.

[0143] Thus, by disposing the fourth auxiliary connection line 90 in the fourth edge series connection area 112 , it is possible to effectively avoid the phenomenon that the welding strip in the fourth edge series connection area 112 has a cold solder joint or poor contact at the second bus bar line 32 , thereby causing the current transmitted from the second bus bar line 32 to be unable to be collected.

[0144] Specifically, Figure 3As shown, in such an embodiment, the number of fourth auxiliary connecting lines 90 can be consistent with the number of second bus grid lines 32, and the two correspond one to one. When the second bus grid line 32 is located in the middle position (that is, there are second collecting grid lines 31 on both sides of the second bus grid line 32), the fourth auxiliary connecting line 90 connects the second bus grid line 32 and connects two second collecting grid lines 31 adjacent to the second bus grid line 32 (that is, the second collecting grid lines 31 located on both sides of the second bus grid line 32 and adjacent to it).

[0145] In some embodiments, the width (length in the first direction) of the fourth auxiliary connection line 90 is greater than the width (length in the second direction) of the portion of the second collection grid line 31 located outside the first series connection area 11 (i.e., the portion of the second collection grid line 31 except the second welding section 301). In this way, since the fourth auxiliary connection line 90 plays the role of transmitting and converging the current when a cold weld occurs at the second bus grid line 32, setting the width of the fourth auxiliary connection line 90 wider can also reduce the transmission loss in the converging process and improve efficiency.

[0146] Embodiment 8 This embodiment provides a battery assembly, including the solar cell 100 in the above embodiment.

[0147] The battery module may include multiple solar cells 100. The multiple solar cells 100 in the battery module may be connected in series in sequence to form a battery string. The battery strings may be connected in series, in parallel, or in a combination of series and parallel to achieve current bus output. For example, the connection between the individual battery cells may be achieved by welding welding strips, and the connection between the individual battery strings may be achieved by bus bars.

[0148] The battery assembly may also include a metal frame, a back plate, photovoltaic glass and an adhesive film (not shown in the figure). The adhesive film may be filled between the light-facing surface and the photovoltaic glass, the backlight surface and the back plate of the solar cell 100, and the adjacent cells. As a filler, it may be a transparent colloid with good light transmission and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0149] Photovoltaic glass can cover the adhesive film on the light-facing surface of the solar cell 100. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the solar cell 100 without affecting the efficiency of the solar cell 100 as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the solar cell 100 together, and the presence of the adhesive film can seal and insulate the solar cell 100 and prevent water and moisture.

[0150] The backplane can be attached to the adhesive film on the backlight surface of the solar cell 100. The backplane can protect and support the solar cell 100 and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the backplane, solar cell 100, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire battery assembly and can stably support and install the battery assembly. For example, the battery assembly can be installed at the required location through the metal frame.

[0151] The beneficial effects of the battery assembly of this embodiment are equivalent to the beneficial effects of the above-mentioned solar cell 100, and will not be described in detail here.

[0152] Embodiment 9 The embodiment provides a photovoltaic assembly, comprising the battery assembly in the above embodiment.

[0153] Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery components. For example, multiple battery components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid. After that, it is connected to the mains network to realize solar power supply.

[0154] The beneficial effects of the photovoltaic system of this embodiment are equivalent to the beneficial effects of the above-mentioned battery assembly, and will not be described in detail here.

[0155] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: It includes a silicon substrate and an electrode disposed on the silicon substrate, wherein the electrode includes a busbar line; The silicon substrate comprises a doping layer; The busbar line comprises: a connecting conductor and a thin busbar line; The connecting conductor extends along a first direction, and the fine gate line is arranged on a surface of the connecting conductor facing the silicon substrate; The connecting conductor is not in physical contact with the doping layer, and the fine gate line is in physical contact with the doping layer.

2. The solar cell according to claim 1, characterized in that The fine gate lines extend along the first direction.

3. The solar cell according to claim 1, characterized in that A plurality of fine gate lines are provided and spaced apart along the first direction.

4. The solar cell according to claim 3, characterized in that: Along the first direction, the fine grid lines are collinear.

5. The solar cell according to claim 3, characterized in that: Along the first direction, at least some of the fine grid lines are staggered.

6. The solar cell according to claim 2, characterized in that: Along the first direction, at least one of the thin gate lines is equidistant from edges of the connecting conductors on both sides.

7. The solar cell according to claim 2, characterized in that: Along the first direction, at least one of the thin gate lines is at different distances from edges of the connecting conductors on both sides.

8. The solar cell according to claim 3, characterized in that: Along the first direction, distances between adjacent fine grid lines are equal.

9. The solar cell according to claim 3, characterized in that: Along the first direction, distances between at least some adjacent fine grid lines are unequal.

10. The solar cell according to claim 1, characterized in that Along the first direction, the total length of the thin gate lines is 10% to 90% of the total length of the connecting conductor.

11. The solar cell according to claim 10, characterized in that Along the first direction, the total length of the thin gate lines is 50% to 90% of the total length of the connecting conductor.

12. The solar cell according to claim 1, characterized in that: Also included is a current collecting wire; The current collecting wire is arranged on the silicon substrate and extends along a second direction, and the second direction intersects with the first direction; At least one end of the connection conductor is connected to the current collecting wire, and the current collecting wire is not in physical contact with the doping layer.

13. The solar cell according to claim 12, characterized in that: The current collecting wire comprises an edge bus line, and the edge bus line is arranged at an edge position of the silicon substrate.

14. The solar cell according to claim 13, characterized in that The silicon substrate has a light-facing surface and a backlight surface that are arranged opposite to each other, and a first region and a second region are alternately arranged along the second direction on the backlight surface, and the polarities of the first region and the second region are different; The bus bar lines include a first bus bar line disposed in the first region and a second bus bar line disposed in the second region.

15. The solar cell according to claim 14, characterized in that The doping layer comprises a first doping layer and a second doping layer, the first doping layer is arranged in the first region, and the second doping layer is arranged in the second region; The thin gate line of the first bus gate line is in physical contact with the first doping layer; The thin gate line of the second bus gate line is in physical contact with the second doping layer.

16. The solar cell according to claim 15, characterized in that The backlight surface has a first edge and a second edge opposite to each other in a first direction, and the backlight surface has a plurality of first series connection areas and a plurality of second series connection areas, wherein the first series connection area includes a first edge series connection area closest to the first edge, and there is no second series connection area between the first edge series connection area and the first edge; The electrodes include a plurality of first electrodes and a plurality of second electrodes, all of the first electrodes and all of the second electrodes are arranged to cross the first series connection area and the second series connection area, the plurality of first electrodes include a plurality of first collecting gate lines and at least one first bus gate line, the first collecting gate line is discontinuous at the first edge series connection area and continuous at the second series connection area, the first bus gate line is continuous at both the first edge series connection area and the second series connection area, and the second electrodes are continuous at the first edge series connection area; The edge bus line includes a first edge bus line, the first edge bus line is closer to the first edge than the first edge series connection area, the first edge bus line is electrically connected to at least part of the first collecting grid line and is electrically connected to the first bus grid line; The solar cell also includes: a first auxiliary connecting line arranged in the first edge series area, in the second direction, the first auxiliary connecting line is provided on at least one side of the first bus bar line, the first auxiliary connecting line connects at least two of the second electrodes located on the same side of the first bus bar line, wherein the at least two second electrodes connected to the first auxiliary connecting line include the second electrode adjacent to the first bus bar line.

17. The solar cell according to claim 16, characterized in that The first edge bus line is electrically connected to all the first collecting gate lines; or The first edge bus line is electrically connected to a portion of the first collecting gate lines, and the number of the first collecting gate lines that are not electrically connected to the first edge bus line is less than or equal to four.

18. The solar cell according to claim 16, characterized in that The width of the first bus gate line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

19. The solar cell according to claim 16, characterized in that: The width of the first edge bus line is greater than the width of a portion of the first collecting gate line located outside the second series connection region.

20. The solar cell according to claim 16, characterized in that: The width of the first auxiliary connection line is greater than the width of a portion of the first collecting gate line located outside the second series connection area.

21. The solar cell according to claim 16, characterized in that: The plurality of second series connection areas include a second edge series connection area closest to the first edge, the first electrode is continuous at the second edge series connection area, and the second electrode is discontinuous at the second edge series connection area. The solar cell also includes a second auxiliary connection line, and the second auxiliary connection line is arranged in the second edge series connection area. In the second direction, the second auxiliary connection line connects the first bus grid line and at least one first collection grid line located on one side of the first bus grid line.

22. The solar cell according to claim 21, characterized in that: The width of the second auxiliary connection line is greater than the width of a portion of the first collecting gate line located outside the second series connection area.

23. The solar cell according to claim 16, characterized in that: The plurality of second serial connection areas include a third edge serial connection area closest to the second edge, and no first serial connection area is provided between the third edge serial connection area and the second edge; The plurality of second electrodes include a plurality of second collecting grid lines and at least one second bus grid line, the second collecting grid lines are discontinuous at the third edge series connection area and continuous at the first series connection area, the second bus grid lines are continuous at the third edge series connection area and the first series connection area, and the first electrodes are continuous at the third edge series connection area; The edge bus line further includes a second edge bus line, the second edge bus line is closer to the second edge than the third edge series connection area, the second edge bus line is electrically connected to at least a portion of the second collecting grid line and is electrically connected to the second bus grid line; The solar cell also includes: a third auxiliary connecting line arranged in the third edge series area, and in the second direction, the third auxiliary connecting line is provided on at least one side of the second bus bar line, and the third auxiliary connecting line connects at least two of the first electrodes located on the same side of the second bus bar line, wherein the at least two first electrodes connected to the third auxiliary connecting line include the first electrode adjacent to the second bus bar line.

24. The solar cell according to claim 23, characterized in that: The second edge bus line is electrically connected to all the second collecting gate lines; or The second edge bus line is electrically connected to a portion of the second collecting gate lines, and the number of the second collecting gate lines that are not electrically connected to the second edge bus line is less than or equal to four.

25. The solar cell according to claim 23, characterized in that The width of the second bus gate line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

26. The solar cell according to claim 23, characterized in that The width of the second edge bus line is greater than the width of a portion of the second collecting gate line located outside the first series connection region.

27. The solar cell according to claim 23, characterized in that The width of the third auxiliary connection line is greater than the width of a portion of the second collecting gate line located outside the first series connection area.

28. The solar cell according to claim 23, characterized in that Several of the first series connection areas include a fourth edge series connection area closest to the second edge, the second electrode is continuous at the fourth edge series connection area, and the first electrode is discontinuous at the fourth edge series connection area. The solar cell also includes a fourth auxiliary connection line, and the fourth auxiliary connection line is arranged in the fourth edge series connection area. In the second direction, the fourth auxiliary connection line connects at least one of the second bus grid lines and at least one of the second collection grid lines located on one side of the second bus grid line.

29. The solar cell according to claim 28, characterized in that The width of the fourth auxiliary connection line is greater than the width of a portion of the second collecting gate line located outside the first series connection area.

30. A battery assembly, characterized in that: A solar cell comprising any one of claims 1 to 29.

31. A photovoltaic system, characterized in that: A battery assembly comprising the battery assembly of claim 30.

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