Electroplating apparatus and electroplating method for a photovoltaic cell

Abstract

The application belongs to the technical field of battery manufacturing, and provides a plating device and a plating method for photovoltaic cells. The plating device comprises a carrier, the carrier comprises a shell and a plurality of partitions in the shell, and the partitions divide the internal space into plating solution areas and electrode areas arranged alternately. The plating solution areas and the electrode areas are open and can contact the supported cell pieces. The plating solution areas are filled with plating solution and / or spray plating solution upward, for providing a plating environment and plating raw materials. The electrode areas are internally provided with working electrodes, the working electrodes are electrically connected with the metal electrode parts of the cell pieces, for causing plating in the plating solution areas and realizing the metallization of the cell pieces. The plating device can be adapted to thin silicon pieces and no hanging plating points. The plating device does not need to deposit a seed layer in advance and does not need to be processed after etching, and is especially suitable for single-side plating of BC cells.

Description

Technical Field

[0001] This invention belongs to the field of battery manufacturing technology, and relates to an electroplating apparatus and electroplating method for photovoltaic cells. Background Technology

[0002] With the expansion of production and application scale in the photovoltaic industry, the manufacturing cost of photovoltaic products has attracted increasing attention. How to effectively reduce costs and improve efficiency has become a common challenge for the photovoltaic industry at this stage.

[0003] In the photovoltaic cost model, the two largest components are silicon wafer cost and metallization cost. To reduce silicon wafer cost, the industry commonly uses thinner wafers, gradually reducing their thickness from 180μm to 130μm, and even 90μm. However, thinner wafers also lead to an increased proportion of fragments during manufacturing, causing increased warpage during thermal processing. Regarding metallization, the cost remains high due to the widespread use of the precious metal silver. While methods to reduce silver usage have some effect, the limitations of screen printing methods make reducing silver consumption increasingly difficult.

[0004] Replacing screen-printed silver grid lines with electroplated copper grid lines is an effective way to reduce costs and improve efficiency. Since the conductivity of electroplated copper is close to that of elemental copper, this superior conductivity results in less heat loss on the grid lines of solar cells. At the same time, copper is about 90% cheaper than silver, so replacing silver grid lines with copper grid lines can significantly reduce the cost of the battery.

[0005] Among mainstream solar cells, BC (Back Contact) cells have no grid lines obstructing the front side while simultaneously achieving passivation on both the front and back sides, resulting in a significantly higher photoelectric conversion efficiency compared to bifacial cells (PERC, TOPCON, HJT, etc.). Since both the positive and negative grid lines of BC cells are integrated on the back of the cell, there's no need to consider light shading losses, allowing for denser grid lines to improve carrier collection. However, when using screen-printed silver paste, cost considerations generally prevent the achievement of ideal metallization patterns. Using copper plating, however, eliminates the cost increase caused by the increased grid pattern, allowing for better utilization of the BC cell's high-efficiency power generation capabilities.

[0006] Existing photovoltaic cell electroplating methods are mainly divided into horizontal electroplating and vertical electroplating. Horizontal electroplating typically uses a method of transporting silicon wafers on rollers. However, as mentioned above, with the thinning of silicon wafers, the risk of breakage increases with roller transport. Vertical electroplating usually requires clamps to hold the silicon wafers while electroplating, which also increases the risk of wafer breakage. Furthermore, the clamping points (plating points) affect the appearance of the cell after electroplating, especially for BC cells, where the clamping points can easily damage the passivation film. In addition, existing methods typically use PVD to sputter a conductive metal layer onto the cell surface as a seed layer before electroplating to improve adhesion and conductivity during electroplating. After the grid line electroplating is completed, the seed layer outside the grid line area is etched away using chemical etching. The PVD and etching processes not only increase process costs, but the copper-containing wastewater generated during etching also creates environmental pressure.

[0007] Considering the problems with existing electroplating technologies, there is a need to develop new electroplating solutions for photovoltaic cells, especially suitable for the high-efficiency, high-quality, and low-cost metallization process of BC cells. Summary of the Invention

[0008] In view of the problems existing in the prior art, the purpose of this invention is to provide an electroplating apparatus and method for photovoltaic cells. The electroplating apparatus includes a carrier, which includes a shell and several internal partitions. The partitions divide the internal space into alternating plating solution zones and electrode zones. The plating solution zones and electrode zones have openings that can contact the supported solar cells. The plating solution zones are filled with electroplating solution and / or sprayed upwards to provide the electroplating environment and plating raw materials. A working electrode is placed inside the electrode zone, and the working electrode forms an electrical connection with the metal electrode portion of the solar cell to enable electroplating to occur in the plating solution zones, thereby achieving metallization of the solar cell. The electroplating apparatus is adaptable to thin silicon wafers and non-dip-plating points. Using the electroplating apparatus, there is no need to pre-deposit a seed layer or perform post-etching processing, making it particularly suitable for single-sided electroplating of BC cells.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides an electroplating apparatus for photovoltaic cells, comprising a carrier; the carrier includes a housing, and a plurality of partitions are disposed in the internal space of the housing; the partitions divide the internal space into alternating plating solution zones and electrode zones; the plating solution zones and the electrode zones have openings on the same side surface of the housing, so that the housing forms a bearing surface, the openings being used to expose the surface of the solar cell to the interior of the plating solution zones and the electrode zones; the plating solution zones are used to be filled with electroplating solution and / or sprayed with electroplating solution from the interior toward the openings, so that the electroplating solution contacts the surface of the solar cell to form a conductive circuit; a working electrode is disposed inside the electrode zones, one end of the working electrode near the openings being electrically connected to the metal electrode portion of the solar cell, and the other end of the working electrode away from the openings being connected to an external power source.

[0011] The electroplating apparatus of this invention uses a carrier to support the solar cells. The carrier has alternating plating solution zones and electrode zones. The plating solution zones contain the electroplating solution, providing the environment and raw materials for electroplating. The plating solution zone flows through the anode and acts as the anode during electroplating. The electrode zones act as cathodes, contacting the solar cells and undergoing a reduction reaction on the surface of the solar cells in the plating solution zone, reducing metal ions in the plating solution and depositing an electroplated layer (such as a metal layer) at the energized location of the solar cells in the plating solution zone. Unlike existing horizontal electroplating apparatuses or processes, this invention eliminates the need for structures or devices such as rollers for continuous transport of silicon wafers. It also differs from existing vertical electroplating apparatuses or processes, eliminating the need for clamps or other structures or devices to hold and suspend the silicon wafers, thus avoiding the influence of clamping points (plating points). The carrier-based support meets the requirements for thinner wafers, facilitating metallization of thinner solar cells and effectively reducing the breakage rate. The electroplating apparatus divides the solar cells into multiple regions for electroplating, overcoming the weakness of weak conductivity on the plating surface, eliminating the need for a sputtered PVD seed layer, and better ensuring coating uniformity.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0013] As a preferred technical solution of the present invention, along the extension direction of the metal electrode in the battery cell, the plating solution area and the electrode area are arranged alternately in sequence; along the direction of alternation, the first area and the last area are edge areas; when the edge area is the plating solution area, it is called the edge plating solution area, and other plating solution areas are called the middle plating solution area; when the edge area is the electrode area, it is called the edge electrode area, and other electrode areas are called the middle electrode area.

[0014] Preferably, the widths of the edge regions are equal along the alternating direction.

[0015] Preferably, the width of the edge plating area is smaller than the width of the middle plating area.

[0016] In this invention, when the edge region is the plating solution region, there is only one intermediate electrode region adjacent to the edge electrode region. In order to avoid the problem that the outermost part of the edge plating solution region is far from the intermediate electrode region, it is preferable to reduce the width of the edge plating solution region so that the electroplating in the edge plating solution region is more uniform.

[0017] As a preferred embodiment of the present invention, along the alternating arrangement direction, the width of the edge plating area is 25% to 75% of the width of the middle plating area.

[0018] As a preferred embodiment of the present invention, the width of each intermediate electrode region is equal along the alternating arrangement direction.

[0019] Preferably, the width of each of the intermediate plating zones is equal along the alternating direction.

[0020] Preferably, along the alternating arrangement direction, the width of the intermediate electrode region is less than or equal to the width of the intermediate plating solution region.

[0021] In this invention, the width of the plating solution area and the electrode area can be reasonably adjusted according to the conductivity of the plating surface of the battery cell. When the conductivity is large, the width of the plating solution area can be appropriately increased and the width of the electrode area can be appropriately decreased, with the aim of ensuring that the electroplating effect of the plating solution area is uniform and consistent. The adjustment is made reasonably according to the actual situation.

[0022] As a preferred embodiment of the present invention, the working electrode in the electrode region includes a first working electrode and a second working electrode that are independent of each other. The first working electrode is used to form an electrical connection with the P-region metal electrode portion of the battery cell, and the second working electrode is used to form an electrical connection with the N-region metal electrode portion of the battery cell.

[0023] This invention, by setting up mutually independent electrodes, allows for the application of different plating voltages as required, and is particularly suitable for cases where the P / N regions of a BC battery are arranged in a forked pattern on the same side.

[0024] As a preferred embodiment of the present invention, the working electrode of the electrode region includes a conductive brush and / or a metal contact electrode.

[0025] In a second aspect, the present invention provides an electroplating method for photovoltaic cells, the electroplating method using the electroplating apparatus described in the first aspect, the electroplating method comprising:

[0026] The battery cell is placed on the support surface of the electroplating apparatus, exposing the plated surface of the battery cell to the interior of the plating solution area and the electrode area; the interior of the plating solution area is kept full of electroplating solution and / or the electroplating solution is sprayed from the interior toward the opening, so that the electroplating solution is in contact with the plated surface of the battery cell, and the working electrode in the electrode area is kept electrically connected to the metal electrode portion on the plated surface of the battery cell, and static electroplating is performed to form an electroplated layer on the plated surface of the battery cell corresponding to the plating solution area, thereby obtaining a partially electroplated battery cell;

[0027] The partially electroplated battery cells are repositioned on the electroplating apparatus, and / or transferred to the bearing surface of another electroplating apparatus, so that the areas on the plated surface of the battery cells where no electroplating layer has been formed are repeatedly subjected to the static electroplating in the plating solution area until a fully electroplated battery cell is obtained.

[0028] In the electroplating method of this invention, after the battery cell is placed on the electroplating apparatus and undergoes its first static electroplating, a portion of the electroplated layer (such as a metal electrode) forms on the surface of the battery cell in the plating solution area. However, no electroplated layer has yet formed on the surface of the battery cell in the electrode area. Therefore, by rearranging the battery cell in the same electroplating apparatus or transferring it to another electroplating apparatus, the area without an electroplated layer is placed in the plating solution area, and static electroplating is performed again. This allows for the step-by-step formation of a complete electroplated layer. In other words, the preparation method can achieve metallization of the battery cell through only two static electroplating operations. Of course, depending on actual needs, more static electroplating operations can be performed or repeated to obtain a battery cell with a fully electroplated surface.

[0029] Furthermore, when readjusting the placement of the cells on the electroplating apparatus, the area of ​​the electroplating apparatus on the supporting surface is larger than the area of ​​the plated surface of the battery cell, so as to leave space for the readjustment. During readjustment, operations such as translational movement or horizontal 180° rotation of the battery cell can be performed. According to automation requirements, a robotic arm and / or a conveying mechanism can be set up. After readjustment, static electroplating is performed again, which can avoid leaving clamping points. Second, when transferring the partially electroplated battery cell to the supporting surface of another electroplating apparatus, the plating solution area and electrode area on the other electroplating apparatus are complementary to those on the first electroplating apparatus, that is, the positions of the plating solution area and electrode area are exactly opposite, so that a fully electroplated battery cell can be obtained through a second static electroplating.

[0030] It is understood that in the electroplating method described in this invention, the carrier of the electroplating apparatus is placed horizontally with the opening and the supporting surface facing upwards. The battery cells are placed on the supporting surface with the plating surface facing downwards. The battery cells are stably supported on the carrier by their own gravity. When a mechanism for spraying electrolyte is provided in the electrolyte coating area, the sprayed electrolyte should be directed towards the opening, i.e., sprayed upwards. Of course, a fixing mechanism can be further provided according to actual needs, but this fixing mechanism should avoid leaving clamping points on the plating surface.

[0031] As a preferred embodiment of the present invention, the battery cell includes a BC battery.

[0032] As a preferred embodiment of the present invention, the electroplated layer includes a seed layer and / or a metal electrode.

[0033] Preferably, the electroplating method further includes: firstly performing static electroplating on the plated surface of the battery cell using a first electroplating solution to form a seed layer, until a battery cell with a seed layer plated on the entire surface is obtained; then performing static electroplating on the seed layer using a second electroplating solution to form a metal electrode, until a battery cell with a metal electrode plated on the entire surface is obtained.

[0034] Preferably, the first electroplating solution contains nickel but not copper; the second electroplating solution contains copper.

[0035] Typically, during the metallization process of solar cells, a seed layer is first formed by electroplating to facilitate the subsequent electroplating and deposition of metal electrodes.

[0036] As a preferred technical solution of the present invention, the working electrode in the electrode region includes a first working electrode and a second working electrode that are independent of each other. The first working electrode is kept electrically connected to the metal electrode portion of the P region of the battery cell, and the second working electrode is kept electrically connected to the metal electrode portion of the N region of the battery cell, so as to perform the static electroplating.

[0037] Preferably, in the static electroplating, the voltage applied to the first working electrode is greater than the voltage applied to the second working electrode.

[0038] In this invention, the reason for applying different voltages to the first working electrode and the second working electrode for individual control and adjustment is that the voltage of the P region on the battery cell is usually higher than that of the N region. This is because the P region is usually doped with group III elements such as boron, and the doping concentration is low, resulting in poor conductivity. At the same time, the majority carriers in the P region are holes, and the built-in electric field needs to be overcome during electroplating. Therefore, the P region requires a higher voltage to ensure the electroplating uniformity of the P region and the N region.

[0039] Thirdly, the present invention provides a photovoltaic cell, which is obtained by the electroplating method described in the second aspect.

[0040] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0041] The electroplating apparatus of this invention uses a carrier to support the solar cells. The carrier has alternating plating solution zones and electrode zones. The plating solution zones contain the electroplating solution, providing the environment and raw materials for electroplating. A conductive circuit is formed between the electrode zones, the solar cells, and the plating solution zones, allowing the electrode zones to energize the solar cells and the plating solution zones, thus enabling electroplating on the surface of the solar cells within the plating solution zones. Unlike existing horizontal electroplating apparatuses or processes, this invention eliminates the need for structures or devices such as rollers for continuous transport of silicon wafers. It also differs from existing vertical electroplating apparatuses or processes, eliminating the need for clamps or other structures or devices to hold and suspend the silicon wafers, thus avoiding the influence of clamping points (plating points). The carrier-based support meets the requirements for thinner wafers, facilitating metallization of thinner solar cells and effectively reducing the breakage rate. The electroplating apparatus divides the solar cells into multiple regions for electroplating, overcoming the weakness of weak conductivity on the plating surface, eliminating the need for a sputtered PVD seed layer, and better ensuring coating uniformity. Attached Figure Description

[0042] Figure 1 This is a top view schematic diagram of the electroplating apparatus for photovoltaic cells provided in Example 1.

[0043] Figure 2 This is a side cross-sectional view of the photovoltaic cell electroplating apparatus provided in Example 1 when the cell is being supported.

[0044] Figure 3 This is a side cross-sectional view of the photovoltaic cell electroplating apparatus provided in Example 2 when the cell is being supported.

[0045] Figure 4 This is a side cross-sectional view of the photovoltaic cell electroplating apparatus provided in Example 3 when the cell is supported.

[0046] Figure 5 This is a side cross-sectional view of the photovoltaic cell electroplating apparatus provided in Example 3 after the carrier cell has been repositioned and its position adjusted.

[0047] In the diagram: 10-outer shell, 20-partition, 30-plating solution area, 31-edge plating solution area, 32-middle plating solution area, 40-electrode area, 41-edge electrode area, 42-middle electrode area, 50-working electrode, 51-first working electrode, 52-second working electrode, 60-battery cell. Detailed Implementation

[0048] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0049] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0050] It should be noted that, due to space limitations and to avoid redundancy, this invention does not exhaustively list all point values ​​within the following numerical range, but it is not limited to the listed values ​​either; other unlisted values ​​within the following numerical range are also applicable.

[0051] Example 1

[0052] This embodiment provides an electroplating apparatus for photovoltaic cells, such as... Figure 1 as well as Figure 2 As shown, the electroplating apparatus includes a carrier; the carrier includes a main body 10, and a plurality of partitions 20 are disposed in the internal space of the main body 10; the partitions 20 divide the internal space into plating solution zones 30 and electrode zones 40 arranged alternately in sequence; the plating solution zones 30 and the electrode zones 40 have openings on the same side surface of the main body 10, so that the main body 10 forms a bearing surface, and the openings expose the surface of the battery cell 60 to the interior of the plating solution zones 30 and the electrode zones 40; the plating solution zones 30 The device is equipped with an internal spray nozzle filled with electroplating solution, which sprays the electroplating solution upwards toward the open end of the plating zone 30, so that the electroplating solution comes into contact with the surface of the battery cell 60. A working electrode 50 is disposed inside the electrode zone 40. One end of the working electrode 50 near the open end is electrically connected to the metal electrode portion of the battery cell 60, and the other end of the working electrode 50 away from the open end is used to connect to an external power source. The bearing surface of the electroplating device has the same size (area) as the plating surface of the battery cell 60.

[0053] Specifically, along the extension direction of the metal electrodes in the battery cell 60, the plating solution area 30 and the electrode area 40 are arranged alternately in sequence; along the direction of alternation, the first area and the last area are edge areas; the edge areas are plating solution areas 30, denoted as edge plating solution areas 31, and the other plating solution areas 30 are denoted as intermediate plating solution areas 32; at this time, all electrode areas 40 are intermediate electrode areas 42; along the direction of alternation, the width of each edge plating solution area 31 is equal, the width of each intermediate plating solution area 32 is equal, and the width of each intermediate electrode area 42 is equal; and the width of the edge plating solution area 31 is less than the width of the intermediate electrode area 42, the width of the intermediate electrode area 42 is less than the width of the intermediate plating solution area 32, and the width of the edge plating solution area 31 is 50% of the width of the intermediate plating solution area 32;

[0054] Each of the electrode regions 40 has a working electrode 50 that includes a first working electrode 51 and a second working electrode 52 that are independent of each other. The first working electrode 51 is used to form an electrical connection with the metal electrode portion of the P region of the battery cell 60, and the second working electrode 52 is used to form an electrical connection with the metal electrode portion of the N region of the battery cell 60. The working electrode 50 of the electrode region 40 is a metal contact electrode.

[0055] Example 2

[0056] This embodiment provides an electroplating apparatus for photovoltaic cells, such as... Figure 3 As shown, in the electroplating apparatus, along the alternating direction, the first and last regions are edge regions; the edge regions are electrode regions 40, denoted as edge electrode regions 41, and the other electrode regions 40 are denoted as intermediate electrode regions 42; at this time, all plating solution regions 30 are intermediate plating solution regions 32; along the alternating direction, the width of each edge electrode region 41 is equal, the width of each intermediate plating solution region 32 is equal, and the width of each intermediate electrode region 42 is equal; and the width of the edge electrode region 41 is less than the width of the intermediate plating solution region 32, the width of the intermediate plating solution region 32 is less than the width of the intermediate electrode region 42, and the width of the edge electrode region 41 is 50% of the width of the intermediate plating solution region 32;

[0057] Furthermore, the electroplating apparatus in this embodiment is complementary to the plating solution area 30 and electrode area 40 of the electroplating apparatus in Embodiment 1. That is, the positions of the plating solution area 30 and electrode area 40 are exactly opposite. Specifically, the width of the edge electrode area 41 in this embodiment is equal to the width of the edge plating solution area 31 in Embodiment 1, the width of the middle electrode area 42 in this embodiment is equal to the width of the middle plating solution area 32 in Embodiment 1, and the width of the middle plating solution area 32 in this embodiment is equal to the width of the middle electrode area 42. Apart from the above, other conditions are exactly the same as in Embodiment 1.

[0058] Example 3

[0059] This embodiment provides an electroplating apparatus for photovoltaic cells, such as... Figure 4 As shown, the size (area) of the bearing surface of the electroplating apparatus is larger than the plating surface of the battery cell 60. When the battery cell 60 is placed on the bearing surface, the electroplating apparatus preferably has other plating solution areas 30 and electrode areas 40 that are not covered. The width of the intermediate electrode area 42 is smaller than the width of the edge plating solution area 31, the width of the edge plating solution area 31 is smaller than the width of the intermediate plating solution area 32, and the width of the edge plating solution area 31 is 75% of the width of the intermediate plating solution area 32. Except for the above, the other conditions are exactly the same as in Example 1.

[0060] Application Example 1

[0061] This application example provides an electroplating method for photovoltaic cells. The electroplating method uses the electroplating apparatus provided in Examples 1 and 2, and the electroplating method includes:

[0062] The BC battery cell 60, which has already formed a seed layer, is placed on the support surface of the electroplating apparatus of Example 1, such as... Figure 2 As shown, the plated surface of the battery cell 60 with the seed layer is exposed to the interior of the plating solution area 30 and the electrode area 40; the interior of the plating solution area 30 is kept full of plating solution, and the spray head continuously sprays the plating solution toward the surface of the battery cell, so that the plating solution is in contact with the plated surface of the battery cell 60, and the working electrode 50 in the electrode area 40 is kept electrically connected to the metal electrode portion on the plated surface of the battery cell 60, and static electroplating is performed to form a metal electrode on the plated surface of the battery cell 60 corresponding to the plating solution area 30, thereby obtaining a partially electroplated battery cell 60;

[0063] The electroplating solution used in the static electroplating all contains copper, and in the static electroplating, the voltage applied to the first working electrode 51 is maintained to be greater than the voltage applied to the second working electrode 52.

[0064] Using a robotic arm, the partially electroplated battery cells 60 are transferred to the bearing surface of the electroplating apparatus in Example 2, such as... Figure 3 As shown, the area on the plated surface of the battery cell 60 where no metal electrode is formed is subjected to static electroplating again in the plating solution area 30 to obtain a battery cell 60 with full-surface electroplating.

[0065] Application Example 2

[0066] This application example provides an electroplating method for photovoltaic cells. The electroplating method uses the electroplating apparatus provided in Example 3, and the electroplating method includes:

[0067] The BC battery cell 60 is placed on the support surface of the electroplating apparatus of Example 3, such as... Figure 4 As shown, the plated surface (without a seed layer) of the battery cell 60 is exposed to the interior of the plating solution area 30 and the electrode area 40; the interior of the plating solution area 30 is kept filled with the first electroplating solution and in contact with the plated surface of the battery cell 60; the working electrode 50 in the electrode area 40 is kept electrically connected to the metal electrode portion on the plated surface of the battery cell 60; static electroplating is performed, and a seed layer is formed on the plated surface of the battery cell 60 corresponding to the plating solution area 30, resulting in a partially electroplated battery cell 60.

[0068] The first electroplating solution contains nickel but not copper, and in the static electroplating, the voltage applied to the first working electrode 51 is maintained greater than the voltage applied to the second working electrode 52.

[0069] The partially electroplated battery cell 60 is translated by a conveying mechanism, the translation distance being the width of the edge plating area 31, such as... Figure 5 As shown, the areas on the plated surface of the battery cell 60 where no seed layer has been formed are subjected to static electroplating again in the plating solution area 30 to obtain a battery cell 60 with a seed layer plated on the entire surface.

[0070] The electroplating solution in the plating zone 30 of the electroplating apparatus is replaced with a second electroplating solution containing copper. The above steps are repeated to form a complete metal electrode on the surface of the seed layer of the battery cell 60 through two-step static electroplating, resulting in a battery cell 60 with a full-surface electroplated metal electrode.

[0071] In summary, the electroplating apparatus for photovoltaic cells described in this invention facilitates step-by-step static electroplating. The cell 60 (e.g., a silicon wafer) is placed on the support surface of a carrier in the first working position. The carrier contains a plating solution area 30 and an electrode area 40, which are spaced apart. The width of the plating solution area 30 can be adjusted according to the conductivity of the silicon wafer's plating surface to ensure uniform plating. The electrode area 40 can use conductive brushes or metal contact electrodes. If the electroplated product is a BC cell (positive / negative electrodes on the same side), the voltage contacting the positive / negative electrodes can be adjusted individually to ensure consistent plating thickness in the P / N regions. After the first electroplating step is completed, the battery cell 60 is moved to the second working position for a second electroplating. The second working position and the first working position can be on two complementary electroplating devices, so that the electroplating area and the electrode area 40 of the two electroplating steps are exactly complementary. Alternatively, the second working position and the first working position can be on the same electroplating device that is larger than the battery cell 60. By readjusting the placement of the battery cell 60, the electroplating area and the electrode area 40 of the two electroplating steps can be made exactly complementary. In short, the electroplating process of the entire surface of the battery cell 60 can be completed after two electroplating steps.

[0072] The electroplating apparatus for photovoltaic cells described in this invention uses a carrier to support the solar cell 60, which can meet the requirements of thinning, reduce the breakage rate, and eliminate the influence of plating points. By dividing the surface of the solar cell 60 to be plated into multiple regions, the electroplating area and the electrode area 40 are arranged alternately. The length of the electroplating area is adjusted according to the conductivity of the surface of the solar cell 60 to be plated, overcoming the disadvantage of weak conductivity of the surface to be plated. It eliminates the need for sputtering a PVD seed layer, improves the uniformity of the plating layer, and eliminates the need for re-etching after electroplating, making it particularly suitable for single-sided electroplating of BC cells. Furthermore, during the electroplating of BC cells, the electroplating voltage of the P-region and N-region can be controlled independently, which is beneficial to improving the uniformity of the plating layer in the P-region and N-region.

[0073] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0075] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An electroplating apparatus for photovoltaic cells, characterized in that, Including vehicles; The carrier includes a main body (10), and a plurality of partitions (20) are provided in the internal space of the main body (10); the partitions (20) divide the internal space into plating solution areas (30) and electrode areas (40) arranged alternately in sequence. The plating solution area (30) and the electrode area (40) have openings on the same side surface of the body (10), so that the body (10) forms a bearing surface, and the openings are used to expose the surface of the battery cell to the interior of the plating solution area (30) and the electrode area (40); The plating solution area (30) is used to fill the interior with electroplating solution and / or spray electroplating solution from the interior toward the opening, so that the electroplating solution comes into contact with the surface of the battery cell to form a conductive circuit; the electrode area (40) is provided with a working electrode (50) inside, the working electrode (50) near the opening is electrically connected to the metal electrode part of the battery cell, and the other end of the working electrode (50) away from the opening is used to connect to an external power source; Along the extension direction of the metal electrodes in the battery cell, the plating solution area (30) and the electrode area (40) are arranged alternately in sequence; along the direction of alternation, the first area and the last area are edge areas; when the edge area is the plating solution area (30), it is called the edge plating solution area (31), and the other plating solution areas (30) are called the middle plating solution area (32); when the edge area is the electrode area (40), it is called the edge electrode area (41), and the other electrode areas (40) are called the middle electrode area (42); along the direction of alternation, the width of the edge areas is equal; the width of the edge plating solution area (31) is smaller than the width of the middle plating solution area (32); Along the alternating direction, the width of each intermediate electrode region (42) is equal; along the alternating direction, the width of each intermediate plating solution region (32) is equal; along the alternating direction, the width of the intermediate electrode region (42) is less than or equal to the width of the intermediate plating solution region (32); The working electrode (50) in the electrode region (40) includes a first working electrode (51) and a second working electrode (52) that are independent of each other. The first working electrode (51) is used to form an electrical connection with the P-region metal electrode of the battery cell, and the second working electrode (52) is used to form an electrical connection with the N-region metal electrode of the battery cell.

2. The electroplating apparatus for photovoltaic cells according to claim 1, characterized in that, Along the alternating direction, the width of the edge plating area (31) is 25% to 75% of the width of the middle plating area (32).

3. The electroplating apparatus for photovoltaic cells according to claim 1, characterized in that, The working electrode (50) of the electrode area (40) includes a conductive brush and / or a metal contact electrode.

4. A method for electroplating photovoltaic cells, characterized in that, The electroplating method uses the electroplating apparatus according to any one of claims 1-3, and the electroplating method includes: The battery cell is placed on the support surface of the electroplating apparatus, exposing the plated surface of the battery cell to the interior of the plating solution area (30) and the electrode area (40); the interior of the plating solution area (30) is kept full of electroplating solution and / or the electroplating solution is sprayed from the interior toward the opening, so that the electroplating solution is in contact with the plated surface of the battery cell, and the working electrode (50) in the electrode area (40) is kept electrically connected to the metal electrode portion on the plated surface of the battery cell, and static electroplating is performed to form an electroplating layer on the plated surface of the battery cell corresponding to the plating solution area (30), thereby obtaining a partially electroplated battery cell; The partially electroplated battery cells are repositioned on the electroplating apparatus and / or the partially electroplated battery cells are transferred to the bearing surface of another electroplating apparatus, so that the area on the plated surface of the battery cell where no electroplating layer is formed is repeatedly subjected to the static electroplating in the plating solution area (30) until a fully electroplated battery cell is obtained. The battery cell includes a BC battery; the electroplating layer includes a seed layer and / or a metal electrode; the electroplating method further includes performing static electroplating on the plated surface of the battery cell using a first electroplating solution to form a seed layer, until a battery cell with a seed layer plated on the entire surface is obtained; then performing static electroplating on the seed layer using a second electroplating solution to form a metal electrode, until a battery cell with a metal electrode plated on the entire surface is obtained; the first electroplating solution contains nickel but does not contain copper; the second electroplating solution contains copper.

5. The electroplating method for photovoltaic cells according to claim 4, characterized in that, The working electrode (50) in the electrode region (40) includes a first working electrode (51) and a second working electrode (52) that are independent of each other. The first working electrode (51) is kept electrically connected to the metal electrode portion of the P region of the battery cell, and the second working electrode (52) is kept electrically connected to the metal electrode portion of the N region of the battery cell, so as to perform the static electroplating.

6. The electroplating method for photovoltaic cells according to claim 4, characterized in that, In the static electroplating, the voltage applied to the first working electrode (51) is greater than the voltage applied to the second working electrode (52).

7. A photovoltaic cell, characterized in that, The photovoltaic cell is obtained by the electroplating method according to any one of claims 4-6.

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