Double-sided electroplating device, double-sided electroplating method and application

Abstract

The present invention provides a double-sided electroplating device and a double-sided electroplating method and application, the device includes at least two electroplating units, the electroplating unit includes a plate conveyor belt, a front electroplating tank, a front electroplating device, a back electroplating tank and a back electroplating device; the plate conveyor belt is used to convey the plate to be plated; adjacent electroplating units are connected by the plate conveyor belt; the front electroplating device and the back electroplating device are respectively arranged on both sides of the plate conveyor belt, the front electroplating device and the back electroplating device respectively include an anode spray plate and a cathode brush insulated from each other, and the anode spray plate is connected to the electroplating tank by a liquid transmission device. The double-sided electroplating device of the present invention can simultaneously and independently prepare electroplating layers of the same or different materials on both sides of the electroplated plate, and by independently controlling the electroplating conditions on both sides, a uniform and effective electroplating layer can be obtained on both sides of the plated plate.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells and relates to a double-sided electroplating device and a double-sided electroplating method and application. Background Art

[0002] As a clean energy, solar energy has received more and more attention in recent years. With the goals of carbon neutrality and carbon peak in my country, the market volume of solar cells as a green conversion solution has increased significantly, and there is greater room for development in the future. At present, the market competition is fierce and new technologies are developing rapidly. Although TOPCon batteries have gradually become the mainstream technology and occupy 70% of the N-type battery market, in order to reduce costs and improve efficiency, 0BB and BC technologies have gradually come into the sight of scientific researchers. BC can place both the PN junction and the metal contact on the back of the solar cell, so that there is no electrode blocking the front of the cell, thereby increasing the area of ​​the cell absorbing sunlight, thereby improving the conversion efficiency and generating more electricity; in addition, the BC structure can be combined with TOPCon and HJT, and has good compatibility. In 0BB, the current transmission path in the fine grid is shorter, which further reduces the power loss; at the same time, 0BB technology removes the main grid, reduces non-silicon costs, and thus reduces the overall cost of photovoltaic cells.

[0003] In order to reduce the amount of silver used, from a process perspective, silver-coated copper paste is used to replace silver paste. This reduces the consumption of silver, but still cannot solve the problem that limited silver reserves cannot meet market demand. Copper has a similar electrical conductivity to silver and is a good candidate to replace silver.

[0004] In addition, the common copper electroplating equipment on the market adopts vertical and horizontal electroplating modes, and vertical electroplating equipment has inevitable disadvantages for BC and 0BB batteries: 1. For 0BB batteries, there is a lack of Pad points, and the conductive fixture is difficult to design. If the clamping points are too dense, the fragmentation rate will rise sharply. Conversely, the conductive effect is very poor and the copper plating effect is difficult to guarantee. 2. The design of the back grid line of the BC battery is complex, which increases the difficulty of fixture design. In addition, the BC battery has high requirements for the front appearance, and the vertical fixture will cause scratches on the front. 3. The uniformity of vertical electroplating is poor, and the copper deposition speed near the conductive clamping point is obviously too fast, resulting in an excessively thick copper layer in this area. 4. In order to ensure the electroplating effect, the vertical electroplating fixture needs to be customized according to the number of battery grid lines, which is costly and has poor adaptability.

[0005] CN116805655A discloses a method for preparing a TOPCon cell and a TOPCon cell prepared thereby. The method for preparing a TOPCon cell comprises the following steps: chemically plating nickel, sintering, removing the oxide layer, electroplating copper, and electroplating silver on a TOPCon solar cell substrate in sequence to obtain a TOPCon solar cell.

[0006] CN220934089U discloses an n-type TOPCon battery, which comprises an n-type silicon substrate, an N-side and a P-side on both side surfaces of the n-type silicon substrate; the N-side and the P-side are independently provided with wire grooves, and grid lines are provided in the wire grooves; the grid lines on the N-side comprise a silver electrode layer, and the silver electrode layer is in contact with the bottom of the wire grooves on the N-side; the grid lines on the P-side comprise a copper electrode layer and a silver-aluminum electrode layer which are stacked, and the copper electrode layer is in contact with the bottom of the wire grooves on the P-side.

[0007] Due to the different properties of the N / P surfaces of the battery cells, their tolerance to the same electroplating process is different, and the effects under the same electroplating solution are different. The preparation process of the battery described in the above scheme is cumbersome, and requires electroplating on both sides separately, and the electroplating uniformity is poor and the efficiency is low. Summary of the invention

[0008] The purpose of the present invention is to provide a double-sided electroplating device, a double-sided electroplating method and an application. The double-sided electroplating device of the present invention can simultaneously and independently prepare electroplating layers of the same or different materials on both sides of the electroplating plate. By independently controlling the electroplating conditions on both sides, a uniform and effective electroplating layer can be obtained on both sides of the plated plate.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a double-sided electroplating device, the device comprising at least two electroplating units, the electroplating unit comprising a plate conveyor belt, a front electroplating tank, a front electroplating device, a back electroplating tank and a back electroplating device;

[0011] The plate conveyor belt is used to convey the plate to be plated;

[0012] In the device, adjacent electroplating units are connected by a plate conveyor belt;

[0013] The front electroplating device and the back electroplating device are respectively arranged on both sides of the plate conveyor belt;

[0014] The front electroplating device comprises a front anode spray plate and a front cathode brush which are insulated from each other;

[0015] The reverse electroplating device comprises a reverse anode spray plate and a reverse cathode brush which are insulated from each other;

[0016] The front anode spray plate is connected to the front electroplating liquid tank via a front liquid transmission device;

[0017] The reverse anode spray plate is connected to the reverse electroplating liquid tank via a reverse liquid transmission device.

[0018] The double-sided electroplating device described in the present invention can electroplate different materials on both sides of the plate to be plated. Different plating solutions are added to the front plating solution tank and the back plating solution tank. A liquid film is formed on the plating surface through a spray device connected to the anode to ensure that it is covered by the liquid. At the same time, a brush is connected to the negative electrode to form a local circuit on the plating surface. Different plating systems are used for the front and back sides of the plate to be plated. The electroplating process is adjusted according to the properties of the front and back sides of the plate to be plated. The front and back sides of the plate to be plated are controlled separately to ensure that the electroplating effects on both sides can reach the optimal level.

[0019] The double-sided electroplating device of the present invention can also realize the simultaneous electroplating of multiple electroplating plates, and the electroplating of the next electroplating plate can be carried out only when the previous electroplating plate enters the next electroplating unit.

[0020] Preferably, in a single electroplating unit of the device, the total projected area of ​​the front electroplating device is ≥ the area of ​​the plate to be plated, and the total projected area of ​​the back electroplating device is ≥ the area of ​​the plate to be plated.

[0021] Preferably, the total spray coverage of the front anode spray disk in the device completely covers the front side of the plate to be plated.

[0022] Preferably, the total spray coverage of the reverse anode spray disk in the device completely covers the reverse side of the plate to be plated.

[0023] In the device described in the present invention, the total spray coverage of the front anode spray disc and the rear anode spray disc (hereinafter collectively referred to as the anode spray disc), that is, all areas that can be spray-covered by the front anode spray disc of all electroplating units. Because the plate conveyor belt is a flowing transmission, and a single electroplating unit needs to include an anode spray disc, a cathode brush and a liquid blocking plate, and the part where the cathode brush and the liquid blocking plate are set cannot be equipped with an anode spray disc, so it is necessary to set an anode spray disc at the corresponding position of other electroplating units to ensure complete electroplating.

[0024] Preferably, the liquid transmission device comprises a liquid transmission pipeline and a transmission pump.

[0025] Preferably, the front electroplating device further includes a front liquid blocking plate.

[0026] Preferably, the front liquid blocking plate is arranged between the front anode spray disc and the front cathode brush.

[0027] Preferably, the reverse-side electroplating device further comprises a reverse-side liquid-blocking plate.

[0028] Preferably, the reverse liquid-blocking plate is disposed between the reverse anode spray disc and the reverse cathode brush.

[0029] In a second aspect, the present invention provides a method for double-sided electroplating, the method using the double-sided electroplating device as described in the first aspect, the method comprising the following steps:

[0030] Add the front electroplating solution into the front electroplating solution tank, add the back electroplating solution into the back electroplating solution tank, place the plate to be plated on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply;

[0031] The front side electroplating liquid is transferred to the front side anode spray plate through the liquid transmission device, and sprayed from the front side anode spray plate to the front side of the plate to be plated. The back side electroplating liquid is transferred to the back side anode spray plate through the liquid transmission device, and sprayed from the back side anode spray plate to the back side of the plate to be plated, so as to perform double-sided electroplating.

[0032] The present invention can realize simultaneous electroplating on both sides by filling the same or different electroplating solutions in the front electroplating tank and the back electroplating tank, and can electroplate electroplating layers of different materials. The two sides are independently controlled, and high-quality electroplating layers can be prepared on both sides.

[0033] In a third aspect, the present invention provides a solar cell, wherein the solar cell is manufactured using the double-sided electroplating device as described in the first aspect;

[0034] The solar cell comprises an inner cell, an N-side conductive layer and a P-side conductive layer, wherein the N-side conductive layer and the P-side conductive layer are arranged on both sides of the inner cell;

[0035] The inner layer battery cell includes any one of a TOPCon battery cell, a HJT battery cell or an 0BB battery cell, or a combination of at least two of them.

[0036] The P side and N side of the solar cell of the present invention are provided with conductive layers of different materials. The different conductive layers on the N / P side are for better matching the collection of electrons and positive ions, improving the opening voltage, and different electroplating solutions for different film layer structures on the front and back sides can adjust the film layer structure to reduce damage to the film layer.

[0037] Preferably, the N-side conductive layer comprises a phosphorus-containing metal layer.

[0038] Preferably, the thickness of the N-side conductive layer is 0.1 μm to 5 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm or 0.5 μm, etc., preferably 0.3 μm to 2.5 μm.

[0039] Preferably, the mass fraction of phosphorus in the N-side conductive layer is 1% to 5%, for example, 1%, 2%, 3%, 4% or 5%.

[0040] Preferably, the P-side conductive layer comprises a boron-containing metal layer.

[0041] Preferably, the thickness of the P-side conductive layer is 0.1 μm to 5 μm, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm or 0.5 μm, etc., preferably 0.3 μm to 2.5 μm.

[0042] Preferably, the mass fraction of boron in the P-side conductive layer is 0.8% to 4%, for example, 0.8%, 1%, 2%, 3% or 4%.

[0043] Preferably, the metal materials in the phosphorus-containing metal layer and the boron-containing metal layer independently include nickel and / or silver.

[0044] Preferably, an N-side metal grid line is also disposed on the N-side conductive layer.

[0045] Preferably, a P-side metal grid line is also disposed on the P-side conductive layer.

[0046] Preferably, the materials of the N-side metal gate lines and the P-side metal gate lines independently include any one of copper, tin or silver, or a combination of at least two of them. Typical but non-limiting combinations include a combination of copper and tin, a combination of copper and silver, or a combination of tin and silver.

[0047] Preferably, the thickness of the N-side metal gate line and the P-side metal gate line is independently 3 μm to 15 μm, for example, 3 μm, 5 μm, 8 μm, 10 μm or 15 μm.

[0048] In a fourth aspect, the present invention provides a method for preparing the solar cell according to the third aspect, the method comprising the following steps:

[0049] Add P-side plating solution to the front plating solution tank of the double-sided electroplating device as described in the first aspect, add N-side plating solution to the back plating solution tank, place the solar cell to be plated on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply;

[0050] The P-side electroplating liquid is transferred to the front anode spray plate through a liquid transfer device, and sprayed from the front anode spray plate to the P-side of the solar cell to be plated. The N-side electroplating liquid is transferred to the back anode spray plate through a liquid transfer device, and sprayed from the back anode spray plate to the N-side of the solar cell to be plated. Double-sided electroplating is performed, and after sintering treatment, a solar cell including an N-side conductive layer and a P-side conductive layer is obtained.

[0051] The preparation process of the solar cell of the present invention is not limited to the front electroplating tank containing P-side electroplating solution or the back electroplating tank containing N-side electroplating solution. The front and back electrolytic tanks can be filled with P-side electroplating solution or N-side electroplating solution as needed.

[0052] Preferably, the P-side electroplating solution comprises a first metal source, a boron source, ethylenediamine, potassium sodium tartrate, a first additive and water.

[0053] Preferably, the first metal source is a first nickel source and / or a first silver source.

[0054] Preferably, the first nickel source comprises nickel chloride.

[0055] Preferably, the first silver source comprises silver nitrate.

[0056] Preferably, the boron source comprises sodium borohydride.

[0057] Preferably, the first additive includes any one of a brightener, a wetting agent or an auxiliary agent, or a combination of at least two of them.

[0058] Preferably, the brightener comprises any one of pyridine, propargyl alcohol or propargylamine, or a combination of at least two thereof.

[0059] Preferably, the wetting agent comprises propylene oxide and / or epichlorohydrin.

[0060] Preferably, the auxiliary agent includes any one of saccharin, bisbenzenesulfonimide or sodium propylene sulfonate, or a combination of at least two thereof.

[0061] Preferably, the mass concentration of the metal source in the P-side electroplating solution is 30 g / L to 50 g / L, for example: 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0062] Preferably, the mass concentration of the boron source in the P-side electroplating solution is 0.2g / L to 0.5g / L, for example: 0.2g / L, 0.25g / L, 0.3g / L, 0.4g / L or 0.5g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0063] Preferably, the mass concentration of ethylenediamine in the P-side electroplating solution is 30 g / L to 50 g / L, for example: 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] Preferably, the mass concentration of sodium potassium tartrate in the P-side electroplating solution is 30 g / L to 50 g / L, for example: 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0065] Preferably, the mass concentration of the first additive in the P-side electroplating solution is 0.5 g / L to 1 g / L, for example: 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L or 1 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0066] Preferably, the pH of the P-side electroplating solution is 13-14, for example, 13, 13.2, 13.5, 13.8 or 14, etc., and is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0067] Preferably, the plating temperature of the P-side electroplating solution is 50°C to 60°C, for example, 50°C, 52°C, 55°C, 58°C or 60°C, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0068] Preferably, the N-side electroplating solution comprises a second metal source, a phosphorus source, a second additive and water.

[0069] Preferably, the second metal source includes a second nickel source and / or a second silver source.

[0070] Preferably, the second nickel source comprises nickel chloride and / or nickel sulfamate.

[0071] Preferably, the second silver source comprises silver nitrate.

[0072] Preferably, the phosphorus source comprises phosphoric acid.

[0073] Preferably, the second additive includes any one of a brightener, a wetting agent or an auxiliary agent, or a combination of at least two of them.

[0074] Preferably, the brightener comprises any one of pyridine, propargyl alcohol or propargylamine, or a combination of at least two thereof.

[0075] Preferably, the wetting agent comprises propylene oxide and / or epichlorohydrin.

[0076] Preferably, the auxiliary agent includes any one of saccharin, bisbenzenesulfonimide or sodium propylene sulfonate, or a combination of at least two thereof.

[0077] Preferably, the second metal source in the N-side electroplating solution is nickel sulfamate, and the mass concentration of the nickel sulfamate is 450g / L to 500g / L, for example: 450g / L, 460g / L, 470g / L, 480g / L, 490g / L or 500g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0078] Preferably, the second metal source in the N-side electroplating solution is nickel chloride, and the mass concentration of the nickel sulfamate is 15g / L to 20g / L, for example: 15g / L, 16g / L, 17g / L, 18g / L, 19g / L or 20g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0079] Preferably, the mass concentration of the phosphorus source in the N-side electroplating solution is 1 g / L to 2 g / L, for example: 1 g / L, 1.2 g / L, 1.5 g / L, 1.8 g / L or 2 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0080] Preferably, the mass concentration of the second additive in the N-side electroplating solution is 0.5 g / L to 1 g / L, for example: 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L or 1 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0081] Preferably, the pH value of the N-side electroplating solution is 1-2, for example, 1, 1.2, 1.5, 1.8 or 2, etc., and is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0082] Preferably, the pH of the N-side electroplating solution is adjusted by aminosulfonic acid.

[0083] Preferably, the plating temperature of the N-side electroplating solution is 60°C to 70°C, for example, 60°C, 62°C, 65°C, 68°C or 70°C, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] Preferably, the N-side electroplating solution also performs light induction during the plating process.

[0085] Under light, electron-hole pairs are separated by the built-in electric field, and the photogenerated electrons are pulled toward the N region. Photogenerated electrons accumulate near the boundary of the N region, and the photoinduced electron transition accelerates the excited electrons and migrates to Ni 2+ Combined with this, reducing the plating time reduces the voltage of the plating process.

[0086] Preferably, the light-induced luminous flux is 4000lm to 8000lm, for example, 4000lm, 5000lm, 6000lm, 7000lm or 8000lm.

[0087] Preferably, the sintering temperature is 280°C to 390°C, for example, 280°C, 290°C, 300°C, 350°C or 390°C.

[0088] Preferably, the sintering treatment time is 1 min to 10 min, for example, 1 min, 2 min, 5 min, 8 min or 10 min.

[0089] Preferably, after obtaining the P-side conductive layer and the N-side conductive layer, a P-side gate line electroplating solution and an N-side gate line electroplating solution are placed in the front-side electroplating solution tank and the back-side electroplating solution tank, respectively, for secondary electroplating.

[0090] Preferably, the P-side gate line electroplating solution comprises copper sulfate, sulfuric acid, hydrochloric acid and water.

[0091] Preferably, the mass concentration of copper sulfate in the P-side gate line electroplating solution is 60g / L to 130g / L, for example: 60g / L, 70g / L, 80g / L, 100g / L, 120g / L or 130g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0092] Preferably, the mass concentration of sulfuric acid in the P-side gate line electroplating solution is 150g / L to 250g / L, for example: 150g / L, 180g / L, 200g / L, 220g / L or 250g / L, etc., not limited to the listed values, other unlisted values ​​within this numerical range are also applicable.

[0093] Preferably, the mass concentration of hydrochloric acid in the P-side gate line electroplating solution is 50ppm to 100ppm, for example: 50ppm, 60ppm, 70ppm, 80ppm, 90ppm or 100ppm, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0094] Preferably, the pH value of the P-side gate line electroplating solution is 1-4.2, for example, 1, 1.5, 2, 3 or 4.2, etc., and is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0095] Preferably, the plating current density of the P-side gate line electroplating solution is 0.5 A / cm 2 ~2.5A / cm 2 , for example: 0.5A / cm 2 , 0.8A / cm 2 , 1A / cm 2 , 2A / cm 2 or 2.5A / cm 2 The present invention is not limited to the numerical values ​​listed, and other numerical values ​​not listed within the numerical range are also applicable.

[0096] Preferably, the plating temperature of the P-side gate line electroplating solution is 20-30°C, for example, 20°C, 22°C, 25°C, 28°C or 30°C, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0097] Preferably, the plating time of the P-side gate line electroplating solution is 7 min to 10 min, for example, 7 min, 7.5 min, 8 min, 9 min or 10 min, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0098] Preferably, the N-side gate line electroplating solution comprises copper pyrophosphate, potassium pyrophosphate, potassium dihydrogen phosphate and water.

[0099] Preferably, the mass concentration of copper pyrophosphate in the N-side gate line electroplating solution is 10 g / L to 70 g / L, for example: 10 g / L, 20 g / L, 30 g / L, 50 g / L, 60 g / L or 70 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0100] Preferably, the mass concentration of potassium pyrophosphate in the N-side gate line plating solution is 25g / L to 90g / L, for example: 25g / L, 30g / L, 50g / L, 70g / L or 90g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0101] Preferably, the mass concentration of potassium dihydrogen phosphate in the N-side gate line plating solution is 40g / L to 110g / L, for example: 40g / L, 50g / L, 80g / L, 90g / L or 110g / L, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0102] Preferably, the pH value of the N-side gate line electroplating solution is 7-10.2, for example, 7, 8, 9, 10 or 10.2, etc., and is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0103] Preferably, the plating current density of the N-side gate line electroplating solution is 0.5 A / cm 2 ~2.5A / cm 2 , for example: 0.5A / cm 2 , 0.8A / cm 2 , 1A / cm 2 , 2A / cm 2 or 2.5A / cm 2 The present invention is not limited to the numerical values ​​listed, and other numerical values ​​not listed within the numerical range are also applicable.

[0104] Preferably, the plating temperature of the N-side gate line electroplating solution is 20-30° C., for example, 20° C., 22° C., 25° C., 28° C. or 30° C., etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0105] Preferably, the plating time of the N-side gate line electroplating solution is 7 min to 10 min, for example, 7 min, 7.5 min, 8 min, 9 min or 10 min, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0106] Compared with the prior art, the present invention has the following beneficial effects:

[0107] (1) The double-sided electroplating device of the present invention can simultaneously and independently prepare electroplating layers of the same or different materials on both sides of the electroplated plate. By independently controlling the electroplating conditions on both sides, uniform and effective electroplating layers can be obtained on both sides of the plated plate.

[0108] (2) The solar cell of the present invention has an N-side conductive layer and a P-side conductive layer on both sides, respectively. The conductive layers with different N / P sides can be doped with high and low concentrations on the battery, thus forming an energy level difference between electrons and positive charges. Electrons move faster to the N-side conductive layer, and positive charges also move faster to the P-side conductive layer, which greatly improves the collection of electrons and positive charges and increases the open circuit voltage.

[0109] (3) The uniformity of the N-side conductive layer of the solar cell produced by the double-sided electroplating method of the present invention can reach within ±0.07μm, the uniformity of the P-side conductive layer can reach within ±0.06μm, the uniformity of the N-side metal grid line can reach within ±0.5μm, and the uniformity of the P-side metal grid line can reach within ±0.6μm. The series resistance Rs of the solar cell can reach 0.15mΩ / cm 2 Within this range, the photoelectric conversion efficiency Eta can reach above 26.30%, the short-circuit current Isc can reach above 7.96A, and the open-circuit voltage Voc can reach above 736mV. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 It is a structural schematic diagram of the electroplating unit in the double-sided electroplating device provided by an embodiment of the present invention, wherein 1 is a TOPCon solar cell sheet, 2 is a P-side conductive layer, 3 is an N-side conductive layer, 4 is a front electrolyte tank, 5 is a back electrolyte tank, 6 is a front anode spray plate, 7 is a front cathode brush, 8 is a back anode spray plate, 9 is a back cathode brush, 10 is a front liquid transmission device, 11 is a back liquid transmission device, 12 is a liquid blocking plate, 13 is a P-side metal grid line, and 14 is an N-side metal grid line. DETAILED DESCRIPTION

[0111] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0112] Example 1

[0113] This embodiment provides a solar cell. In the preparation process of the solar cell, the structure schematic diagram of the electroplating unit of the double-sided electroplating device is as follows: Figure 1 As shown:

[0114] The electroplating unit includes a plate conveyor belt, a front electroplating tank 4, a front electroplating device, a back electroplating tank 5 and a back electroplating device;

[0115] The front electroplating device and the back electroplating device are arranged on both sides of the plate conveyor belt;

[0116] The front electroplating device comprises a front anode spray plate 6 and a front cathode brush 7 which are insulated from each other;

[0117] The reverse electroplating device comprises a reverse anode spray plate 8 and a reverse cathode brush 9 which are insulated from each other;

[0118] A liquid transfer device 10 is provided between the front anode spray plate 6 and the front electroplating liquid tank 4 and between the back anode spray plate 8 and the back electroplating liquid tank 5 respectively.

[0119] The plate conveyor belt is used for solar cells, and the solar cells include a TOPCon solar cell 1 and a P-side conductive layer 2 and an N-side conductive layer 3 arranged on both sides of the TOPCon solar cell 1, a P-side metal grid line 13 is arranged on the P-side conductive layer 2, and an N-side metal grid line 14 is arranged on the N-side conductive layer 3 (the solar cell is not a part of the device, and in order to clearly show the working principle of the device, the structures of the two electroplatings are shown here, but the metal grid line can only be prepared after the P-side conductive layer 2 and the N-side conductive layer 3 are completely prepared, so the conductive layers on both sides here are complete structures);

[0120] The total spray coverage of the front anode spray plate 6 in the device completely covers the front side of the plate to be plated;

[0121] The total spray coverage of the reverse anode spray plate 8 in the device completely covers the reverse side of the plate to be plated;

[0122] The liquid transmission device 10 includes a liquid transmission pipeline and a transmission pump.

[0123] The front electroplating device and the back electroplating device further include a liquid blocking plate 12;

[0124] The liquid blocking plate 12 is disposed between the front anode spray plate 6 and the front cathode brush 7;

[0125] The liquid blocking plate 12 is disposed between the reverse anode spray disc 8 and the reverse cathode brush 9 .

[0126] The preparation method of the solar cell is as follows:

[0127] A P-side electroplating solution is prepared, wherein the mass concentration of nickel chloride in the P-side electroplating solution is 40 g / L, the mass concentration of sodium borohydride is 0.3 g / L, the mass concentration of ethylenediamine is 40 g / L, the mass concentration of potassium sodium tartrate is 40 g / L, the mass concentration of additives such as brightener propargyl alcohol, wetting agent propylene oxide, and auxiliary agent sodium propylene sulfonate is 0.8 g / L, and the pH of the P-side electroplating solution is 13.5; an N-side electroplating solution is prepared, wherein the mass concentration of nickel aminosulfonate in the N-side electroplating solution is 480 g / L, the mass concentration of nickel chloride is 18 g / L, the mass concentration of phosphoric acid is 1.5 g / L, the mass concentration of additives such as brightener propargyl alcohol, wetting agent propylene oxide, and auxiliary agent sodium propylene sulfonate is 25 g / L, and the pH of the N-side electroplating solution is adjusted to 1.5 with aminosulfonic acid. Prepare an N-side grid line electroplating solution, wherein the mass concentration of copper pyrophosphate in the N-side grid line electroplating solution is 50 g / L, the mass concentration of potassium pyrophosphate is 50 g / L, the mass concentration of potassium dihydrogen phosphate is 80 g / L, and the pH is 8; prepare a P-side grid line electroplating solution, wherein the mass concentration of copper sulfate in the P-side grid line electroplating solution is 80 g / L, the mass concentration of sulfuric acid is 200 g / L, the mass concentration of hydrochloric acid is 80 ppm, and the pH is 2;

[0128] Add P-side plating solution to the front plating solution tank of the double-sided electroplating device, add N-side plating solution to the back plating solution tank, place TOPCon solar cells on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply;

[0129] The P-side electroplating liquid is transferred to the front anode spray plate through a liquid transfer device, and sprayed from the front anode spray plate to the P-side of the TOPCon solar cell, and the plating temperature is 55°C. The N-side electroplating liquid is transferred to the back anode spray plate through a liquid transfer device, and sprayed from the back anode spray plate to the N-side of the solar cell to be plated, and the plating temperature is 65°C, wherein the N-side 6 is double-sided electroplated under 000lm light, and subjected to a heat treatment at 350°C for 5min, to obtain a solar cell comprising an N-side conductive layer 3 (P-Ni) with a thickness of 2μm and a P-side conductive layer 2 (B-Ni) with a thickness of 3μm, wherein the mass proportion of phosphorus in the N-side conductive layer 3 is 3%, and the mass proportion of boron in the P-side conductive layer 2 is 2%;

[0130] The P-side grid line plating solution is added to the front plating solution tank of the double-sided electroplating device, and the N-side grid line plating solution is added to the back plating solution tank of the double-sided electroplating device. Secondary electroplating is performed on the P-side conductive layer and the N-side conductive layer respectively. The plating current density of the P-side grid line plating solution is 1A / cm 2 , the temperature is 25℃, the plating time is 8min, and the plating current density of the N-side gate line plating solution is 1A / cm 2 , the temperature is 25° C., the electroplating time is 8 min, a P-side metal gate line 13 with a thickness of 8 μm is formed on the P-side conductive layer 2 , and an N-side metal gate line 14 with a thickness of 8 μm is formed on the N-side conductive layer 3 .

[0131] Example 2

[0132] This embodiment provides a solar cell. In the preparation process of the solar cell, the structure schematic diagram of the electroplating unit of the double-sided electroplating device is as follows: Figure 1 As shown:

[0133] The electroplating unit includes a plate conveyor belt, a front electroplating tank 4, a front electroplating device, a back electroplating tank 5 and a back electroplating device;

[0134] The front electroplating device and the back electroplating device are arranged on both sides of the plate conveyor belt;

[0135] The front electroplating device comprises a front anode spray plate 6 and a front cathode brush 7 which are insulated from each other;

[0136] The reverse electroplating device comprises a reverse anode spray plate 8 and a reverse cathode brush 9 which are insulated from each other;

[0137] A liquid transfer device 10 is provided between the front anode spray plate 6 and the front electroplating liquid tank 4 and between the back anode spray plate 8 and the back electroplating liquid tank 5 respectively.

[0138] The plate conveyor belt is used for solar cells, and the solar cells include a TOPCon solar cell 1 and a P-side conductive layer 2 and an N-side conductive layer 3 arranged on both sides of the TOPCon solar cell 1, a P-side metal grid line 13 is arranged on the P-side conductive layer 2, and an N-side metal grid line 14 is arranged on the N-side conductive layer 3 (the solar cell is not a part of the device, and in order to clearly show the working principle of the device, the structures of the two electroplatings are shown here, but the metal grid line can only be prepared after the P-side conductive layer 2 and the N-side conductive layer 3 are completely prepared, so the conductive layers on both sides here are complete structures);

[0139] The total spray coverage of the front anode spray plate 6 in the device completely covers the front side of the plate to be plated;

[0140] The total spray coverage of the reverse anode spray plate 8 in the device completely covers the reverse side of the plate to be plated;

[0141] The liquid transmission device 10 includes a liquid transmission pipeline and a transmission pump.

[0142] The front electroplating device and the back electroplating device further include a liquid blocking plate 12;

[0143] The liquid blocking plate 12 is disposed between the front anode spray plate 6 and the front cathode brush 7;

[0144] The liquid blocking plate 12 is disposed between the reverse anode spray disc 8 and the reverse cathode brush 9 .

[0145] The preparation method of the solar cell is as follows:

[0146] A P-side electroplating solution is prepared, wherein the mass concentration of nickel chloride in the P-side electroplating solution is 20 g / L, the mass concentration of sodium borohydride is 0.2 g / L, the mass concentration of ethylenediamine is 30 g / L, the mass concentration of potassium sodium tartrate is 30 g / L, the mass concentration of additive brightener propargyl alcohol, the mass concentration of wetting agent propylene oxide, the mass concentration of auxiliary agent sodium propylene sulfonate is 0.5 g / L, and the pH of the P-side electroplating solution is 13; an N-side electroplating solution is prepared, wherein the mass concentration of nickel aminosulfonate in the N-side electroplating solution is 450 g / L, the mass concentration of nickel chloride is 15 g / L, the mass concentration of phosphoric acid is 1 g / L, the mass concentration of additive brightener propargyl alcohol, the mass concentration of wetting agent propylene oxide, the mass concentration of auxiliary agent sodium propylene sulfonate is 20 g / L, and the pH of the N electroplating solution is adjusted to 2 with aminosulfonic acid. Prepare an N-side grid line electroplating solution, wherein the mass concentration of copper pyrophosphate in the N-side grid line electroplating solution is 10 g / L, the mass concentration of potassium pyrophosphate is 25 g / L, the mass concentration of potassium dihydrogen phosphate is 40 g / L, and the pH is 7; prepare a P-side grid line electroplating solution, wherein the mass concentration of copper sulfate in the P-side grid line electroplating solution is 60 g / L, the mass concentration of sulfuric acid is 150 g / L, the mass concentration of hydrochloric acid is 50 ppm, and the pH is 1;

[0147] Add P-side plating solution to the front plating solution tank of the double-sided electroplating device, add N-side plating solution to the back plating solution tank, place TOPCon solar cells on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply;

[0148] The P-side electroplating liquid is transferred to the front anode spray plate through a liquid transfer device, and sprayed from the front anode spray plate to the P-side of the TOPCon solar cell, and the plating temperature is 50°C. The N-side electroplating liquid is transferred to the back anode spray plate through a liquid transfer device, and sprayed from the back anode spray plate to the N-side of the solar cell to be plated, and the plating temperature is 60°C, wherein the N-side is double-sidedly electroplated under 4000lm of light, and subjected to a heat treatment at 390°C for 10 minutes, to obtain a solar cell comprising an N-side conductive layer 3 (P-Ni) with a thickness of 0.3μm and a P-side conductive layer 2 (B-Ni) with a thickness of 0.1μm, wherein the mass proportion of phosphorus in the N-side conductive layer 3 is 1%, and the mass proportion of boron in the P-side conductive layer 2 is 0.8%;

[0149] The P-side grid line plating solution is added to the front plating solution tank of the double-sided electroplating device, and the N-side grid line plating solution is added to the back plating solution tank of the double-sided electroplating device. Secondary electroplating is performed on the P-side conductive layer and the N-side conductive layer respectively. The plating current density of the P-side grid line plating solution is 0.5A / cm 2 , the temperature is 25℃, the plating time is 10min, and the plating current density of the N-side gate line plating solution is 0.5A / cm 2 , the temperature is 25° C., the electroplating time is 10 min, a P-side metal gate line 13 with a thickness of 15 μm is formed on the P-side conductive layer 2, and an N-side metal gate line 14 with a thickness of 15 μm is formed on the N-side conductive layer 3.

[0150] Example 3

[0151] This embodiment provides a solar cell. In the preparation process of the solar cell, the structure schematic diagram of the electroplating unit of the double-sided electroplating device is as follows: Figure 1 As shown:

[0152] The electroplating unit includes a plate conveyor belt, a front electroplating tank 4, a front electroplating device, a back electroplating tank 5 and a back electroplating device;

[0153] The front electroplating device and the back electroplating device are arranged on both sides of the plate conveyor belt;

[0154] The front electroplating device comprises a front anode spray plate 6 and a front cathode brush 7 which are insulated from each other;

[0155] The reverse electroplating device comprises a reverse anode spray plate 8 and a reverse cathode brush 9 which are insulated from each other;

[0156] A liquid transfer device 10 is provided between the front anode spray plate 6 and the front electroplating liquid tank 4 and between the back anode spray plate 8 and the back electroplating liquid tank 5 respectively.

[0157] The plate conveyor belt is used for solar cells, and the solar cells include a TOPCon solar cell 1 and a P-side conductive layer 2 and an N-side conductive layer 3 arranged on both sides of the TOPCon solar cell 1, a P-side metal grid line 13 is arranged on the P-side conductive layer 2, and an N-side metal grid line 14 is arranged on the N-side conductive layer 3 (the solar cell is not a part of the device, and in order to clearly show the working principle of the device, the structures of the two electroplatings are shown here, but the metal grid line can only be prepared after the P-side conductive layer 2 and the N-side conductive layer 3 are completely prepared, so the conductive layers on both sides here are complete structures);

[0158] The total spray coverage of the front anode spray plate 6 in the device completely covers the front side of the plate to be plated;

[0159] The total spray coverage of the reverse anode spray plate 8 in the device completely covers the reverse side of the plate to be plated;

[0160] The liquid transmission device 10 includes a liquid transmission pipeline and a transmission pump.

[0161] The front electroplating device and the back electroplating device further include a liquid blocking plate 12;

[0162] The liquid blocking plate 12 is disposed between the front anode spray plate 6 and the front cathode brush 7;

[0163] The liquid blocking plate 12 is disposed between the reverse anode spray disc 8 and the reverse cathode brush 9 .

[0164] The preparation method of the solar cell is as follows:

[0165] A P-side electroplating solution is prepared, wherein the mass concentration of nickel chloride in the P-side electroplating solution is 50 g / L, the mass concentration of sodium borohydride is 0.5 g / L, the mass concentration of ethylenediamine is 50 g / L, the mass concentration of potassium sodium tartrate is 50 g / L, the mass concentration of additive brightener propargyl alcohol, the mass concentration of wetting agent propylene oxide, the mass concentration of auxiliary agent sodium propylene sulfonate is 1 g / L, and the pH of the P-side electroplating solution is 14; an N-side electroplating solution is prepared, wherein the mass concentration of nickel aminosulfonate in the N-side electroplating solution is 500 g / L, the mass concentration of nickel chloride is 20 g / L, the mass concentration of phosphoric acid is 2 g / L, the mass concentration of additive brightener propargyl alcohol, the mass concentration of wetting agent propylene oxide, the mass concentration of auxiliary agent sodium propylene sulfonate is 30 g / L, and the pH of the N electroplating solution is adjusted to 1 with aminosulfonic acid. Prepare an N-side gate line electroplating solution, wherein the mass concentration of copper pyrophosphate in the N-side gate line electroplating solution is 70 g / L, the mass concentration of potassium pyrophosphate is 90 g / L, the mass concentration of potassium dihydrogen phosphate is 110 g / L, and the pH is 10.2; prepare a P-side gate line electroplating solution, wherein the mass concentration of copper sulfate in the P-side gate line electroplating solution is 130 g / L, the mass concentration of sulfuric acid is 250 g / L, the mass concentration of hydrochloric acid is 100 ppm, and the pH is 4.2;

[0166] Add P-side plating solution to the front plating solution tank of the double-sided electroplating device, add N-side plating solution to the back plating solution tank, place TOPCon solar cells on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply;

[0167] The P-side electroplating liquid is transferred to the front anode spray plate through a liquid transfer device, and sprayed from the front anode spray plate to the P-side of the TOPCon solar cell, and the plating temperature is 50°C. The N-side electroplating liquid is transferred to the back anode spray plate through a liquid transfer device, and sprayed from the back anode spray plate to the N-side of the solar cell to be plated, and the plating temperature is 60°C, wherein the N-side is illuminated with 8000lm of light, double-sided electroplating is performed, and after heat treatment at 280°C for 1min, a solar cell comprising an N-side conductive layer 3 (P-Ni) with a thickness of 2.5μm and a P-side conductive layer 2 (B-Ni) with a thickness of 2.5μm is obtained, wherein the mass proportion of phosphorus in the N-side conductive layer 3 is 5%, and the mass proportion of boron in the P-side conductive layer 2 is 4%;

[0168] The P-side grid line plating solution is added to the front plating solution tank of the double-sided electroplating device, and the N-side grid line plating solution is added to the back plating solution tank of the double-sided electroplating device. Secondary electroplating is performed on the P-side conductive layer and the N-side conductive layer respectively. The plating current density of the P-side grid line plating solution is 2.5A / cm 2 , the temperature is 25℃, the plating time is 7min, and the plating current density of the N-side gate line plating solution is 2.5A / cm 2, the temperature is 25° C., the electroplating time is 7 minutes, and a P-side metal gate line 13 with a thickness of 3 μm is formed on the P-side conductive layer 2 , and an N-side metal gate line 14 with a thickness of 3 μm is formed on the N-side conductive layer 3 .

[0169] Example 4

[0170] The only difference between this embodiment and the first embodiment is that the mass fraction of phosphorus in the N-side conductive layer is 0.5%, and the other conditions and parameters are exactly the same as those in the first embodiment.

[0171] Example 5

[0172] The only difference between this embodiment and the first embodiment is that the mass fraction of phosphorus in the N-side conductive layer is 6%, and the other conditions and parameters are exactly the same as those in the first embodiment.

[0173] Example 6

[0174] The only difference between this embodiment and the first embodiment is that the mass fraction of the boron element in the P-side conductive layer is 0.4%, and the other conditions and parameters are exactly the same as those in the first embodiment.

[0175] Example 7

[0176] The only difference between this embodiment and the first embodiment is that the mass fraction of the boron element in the P-side conductive layer is 5%, and the other conditions and parameters are exactly the same as those in the first embodiment.

[0177] Comparative Example 1

[0178] According to the traditional scheme of mask → horizontal / vertical double-sided nickel plating → horizontal / vertical double-sided copper plating → mask removal → heat treatment, both sides are electroplated simultaneously with the same solution.

[0179] Comparative Example 2

[0180] Perovskite solar cells are prepared according to the traditional scheme of laser film opening → pre-cleaning → horizontal / vertical double-sided nickel plating → horizontal / vertical double-sided copper plating → heat treatment.

[0181] Performance Testing:

[0182] The solar cells prepared in the embodiment and the comparative example were tested using an X-ray film thickness meter, a solar cell efficiency tester, and an electron microscope. The test results are shown in Table 1-2:

[0183] Table 1

[0184]

[0185]

[0186] Table 2

[0187] <![CDATA[Rs(mΩ / cm 2 )]]> Eta(%) Isc(A) Voc(mV) Example 1 0.11 26.41 7.99 737 Example 2 0.11 26.39 7.98 737 Example 3 0.12 26.39 7.98 736 Example 4 0.13 26.38 7.98 736 Example 5 0.14 26.33 7.97 736 Example 6 0.15 26.30 7.97 736 Example 7 0.15 26.31 7.96 736 Comparative Example 1 0.3 26.17 7.88 729 Comparative Example 2 0.4 26.11 7.90 728

[0188] As can be seen from Table 1-2, from Examples 1-7, the uniformity of the N-side conductive layer in the solar cell prepared by the double-sided electroplating method of the present invention can reach within ±0.07μm, the uniformity of the P-side conductive layer can reach within ±0.06μm, the uniformity of the N-side metal grid line can reach within ±0.5μm, the uniformity of the P-side metal grid line can reach within ±0.6μm, and the series resistance Rs of the solar cell can reach 0.15mΩ / cm 2 Within this range, the photoelectric conversion efficiency Eta can reach above 26.30%, the short-circuit current Isc can reach above 7.96A, and the open-circuit voltage Voc can reach above 736mV.

[0189] By comparing Example 1 with Examples 4-5, it can be seen that the mass fraction of phosphorus in the N-side conductive layer of the solar cell of the present invention affects its performance. When the mass fraction of phosphorus is controlled at 1% to 5%, the performance of the solar cell is better. If the mass fraction of phosphorus is too low, the electron transmission effect is not obvious, which is close to the effect of direct Ni electroplating. If the mass fraction of phosphorus is too high, the battery contact resistance increases.

[0190] By comparing Example 1 with Examples 6-7, it can be seen that the mass fraction of the boron element in the P-side conductive layer of the solar cell of the present invention affects its performance. When the mass fraction of the boron element is controlled at 0.8% to 4%, the performance of the solar cell is better. If the mass fraction of the boron element is too low, the hole transport effect is not obvious, which is close to the effect of direct Ni electroplating. If the mass fraction of the boron element is too high, the resistivity increases, resulting in an increase in the battery contact resistance.

[0191] By comparing Example 1 and Comparative Example 1, it can be seen that the traditional electroplating method cannot set different conductive layers according to different doping elements, so that the conductive Rs of one side is always too high, and the thickness uniformity of the nickel layer and the copper layer is also quite different. The present invention can use different conductive layers according to different doping elements in the N / P zone to dope the conductive layer, and the contact resistance is significantly reduced.

[0192] From the comparison between Example 1 and Comparative Example 2, it can be seen that the double-sided electroplating method of the present invention causes less corrosion damage to the film layer, and the original passivation effect and short-circuit current will not be lost.

[0193] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A double-sided electroplating device, characterized in that: The device comprises at least two electroplating units, wherein the electroplating units comprise a plate conveyor belt, a front electroplating tank, a front electroplating device, a back electroplating tank and a back electroplating device; The plate conveyor belt is used to convey the plate to be plated; In the device, adjacent electroplating units are connected by a plate conveyor belt; The front electroplating device and the back electroplating device are respectively arranged on both sides of the plate conveyor belt; The front electroplating device comprises a front anode spray plate and a front cathode brush which are insulated from each other; The reverse electroplating device comprises a reverse anode spray plate and a reverse cathode brush which are insulated from each other; The front anode spray plate is connected to the front electroplating liquid tank via a front liquid transmission device; The reverse anode spray plate is connected to the reverse electroplating liquid tank via a reverse liquid transmission device.

2. The double-sided electroplating device according to claim 1, characterized in that: In a single electroplating unit of the device, the total projected area of ​​the front electroplating device is ≥ the area of ​​the plate to be plated, and the total projected area of ​​the back electroplating device is ≥ the area of ​​the plate to be plated; Preferably, the total spray coverage of the front anode spray disc in the device completely covers the front side of the plate to be plated; Preferably, the total spray coverage of the reverse anode spray plate in the device completely covers the reverse side of the plate to be plated; Preferably, the liquid transmission device comprises a liquid transmission pipeline and a transmission pump.

3. The double-sided electroplating device according to claim 1 or 2, characterized in that: The front electroplating device also includes a front liquid blocking plate; Preferably, the front liquid blocking plate is arranged between the front anode spray plate and the front cathode brush; Preferably, the reverse-side electroplating device further comprises a reverse-side liquid-blocking plate; Preferably, the reverse liquid-blocking plate is disposed between the reverse anode spray disc and the reverse cathode brush.

4. A double-sided electroplating method, characterized in that: The method uses the double-sided electroplating device according to any one of claims 1 to 3, and the method comprises the following steps: Add the front electroplating solution into the front electroplating solution tank, add the back electroplating solution into the back electroplating solution tank, place the plate to be plated on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, and connect the front cathode brush and the back cathode brush to the cathode of the power supply; The front side electroplating liquid is transferred to the front side anode spray plate through the liquid transmission device, and sprayed from the front side anode spray plate to the front side of the plate to be plated. The back side electroplating liquid is transferred to the back side anode spray plate through the liquid transmission device, and sprayed from the back side anode spray plate to the back side of the plate to be plated, so as to perform double-sided electroplating.

5. A solar cell, characterized in that: The solar cell is made using the double-sided electroplating device as described in any one of claims 1 to 3; The solar cell comprises an inner cell, an N-side conductive layer and a P-side conductive layer, wherein the N-side conductive layer and the P-side conductive layer are arranged on both sides of the inner cell; The inner layer battery cell includes any one of a TOPCon battery cell, a HJT battery cell or an 0BB battery cell, or a combination of at least two of them.

6. The solar cell according to claim 5, characterized in that The N-side conductive layer includes a phosphorus-containing metal layer; Preferably, the thickness of the N-side conductive layer is 0.1 μm to 5 μm, preferably 0.3 μm to 2.5 μm; Preferably, the mass fraction of phosphorus in the N-side conductive layer is 1% to 5%; Preferably, the P-side conductive layer comprises a boron-containing metal layer; Preferably, the thickness of the P-side conductive layer is 0.1 μm to 5 μm, preferably 0.3 μm to 2.5 μm; Preferably, the mass fraction of boron in the P-side conductive layer is 0.8% to 4%; Preferably, the metal materials in the phosphorus-containing metal layer and the boron-containing metal layer independently include nickel and / or silver.

7. The solar cell according to claim 5 or 6, characterized in that: The N-side conductive layer is also provided with an N-side metal grid line; Preferably, a P-side metal grid line is also provided on the P-side conductive layer; Preferably, the materials of the N-side metal grid lines and the P-side metal grid lines independently include any one of copper, tin or silver, or a combination of at least two of them; Preferably, the thickness of the N-side metal gate line and the P-side metal gate line is independently 3 μm to 15 μm.

8. A method for preparing a solar cell according to any one of claims 5 to 7, characterized in that: The preparation method comprises the following steps: Add P-side plating solution to the front plating solution tank of the double-sided electroplating device as claimed in any one of claims 1 to 3, add N-side plating solution to the back plating solution tank, place the solar cell to be plated on the plate conveyor belt, connect the front anode spray plate and the back anode spray plate to the anode of the power supply, respectively, and connect the front cathode brush and the back cathode brush to the cathode of the power supply, respectively; The P-side electroplating liquid is transferred to the front anode spray plate through a liquid transfer device, and sprayed from the front anode spray plate to the P-side of the solar cell to be plated. The N-side electroplating liquid is transferred to the back anode spray plate through a liquid transfer device, and sprayed from the back anode spray plate to the N-side of the solar cell to be plated. Double-sided electroplating is performed, and after sintering treatment, a solar cell including an N-side conductive layer and a P-side conductive layer is obtained.

9. The preparation method according to claim 8, characterized in that: The P-side electroplating solution comprises a first metal source, a boron source, ethylenediamine, potassium sodium tartrate, a first additive and water; Preferably, the first metal source is a first nickel source and / or a first silver source; Preferably, the first nickel source comprises nickel chloride; Preferably, the first silver source comprises silver nitrate; Preferably, the boron source comprises sodium borohydride; Preferably, the first additive comprises any one of a brightener, a wetting agent or an auxiliary agent, or a combination of at least two thereof; Preferably, the brightener comprises any one of pyridine, propargyl alcohol or propargylamine, or a combination of at least two thereof; Preferably, the wetting agent comprises propylene oxide and / or epichlorohydrin; Preferably, the auxiliary agent comprises any one of saccharin, bisbenzenesulfonimide or sodium propylene sulfonate or a combination of at least two thereof; Preferably, the mass concentration of the metal source in the P-side electroplating solution is 30 g / L to 50 g / L; Preferably, the mass concentration of the boron source in the P-side electroplating solution is 0.2 g / L to 0.5 g / L; Preferably, the mass concentration of ethylenediamine in the P-side electroplating solution is 30 g / L to 50 g / L; Preferably, the mass concentration of potassium sodium tartrate in the P-side electroplating solution is 30 g / L to 50 g / L; Preferably, the mass concentration of the first additive in the P-side electroplating solution is 0.5 g / L to 1 g / L; Preferably, the pH of the P-side electroplating solution is 13-14; Preferably, the plating temperature of the P-side electroplating solution is 50°C to 60°C; Preferably, the N-side electroplating solution comprises a second metal source, a phosphorus source, a second additive and water; Preferably, the second metal source comprises a second nickel source and / or a second silver source; Preferably, the second nickel source comprises nickel chloride and / or nickel sulfamate; Preferably, the second silver source comprises silver nitrate; Preferably, the phosphorus source comprises phosphoric acid; Preferably, the second additive comprises any one or a combination of at least two of a brightener, a wetting agent or an auxiliary agent; Preferably, the brightener comprises any one of pyridine, propargyl alcohol or propargylamine, or a combination of at least two thereof; Preferably, the wetting agent comprises propylene oxide and / or epichlorohydrin; Preferably, the auxiliary agent comprises any one of saccharin, bisbenzenesulfonimide or sodium propylene sulfonate or a combination of at least two thereof; Preferably, the second metal source in the N-side electroplating solution is nickel sulfamate, and the mass concentration of the nickel sulfamate is 450 g / L to 500 g / L; Preferably, the second metal source in the N-side electroplating solution is nickel chloride, and the mass concentration of the nickel sulfamate is 15 g / L to 20 g / L; Preferably, the mass concentration of the phosphorus source in the N-side electroplating solution is 1 g / L to 2 g / L; Preferably, the mass concentration of the second additive in the N-side electroplating solution is 0.5 g / L to 1 g / L; Preferably, the pH of the N-side electroplating solution is 1 to 2; Preferably, the pH of the N-side electroplating solution is adjusted by aminosulfonic acid; Preferably, the plating temperature of the N-side electroplating solution is 60° C. to 70° C.; Preferably, the N-side electroplating solution is also photo-induced during the plating process; Preferably, the light-induced luminous flux is 4000lm to 8000lm; Preferably, the sintering temperature is 280°C to 390°C; Preferably, the sintering treatment time is 1 min to 10 min.

10. The preparation method according to claim 8 or 9, characterized in that: After obtaining the P-side conductive layer and the N-side conductive layer, a P-side gate line electroplating solution and an N-side gate line electroplating solution are placed in the front-side electroplating solution tank and the back-side electroplating solution tank, respectively, to perform secondary electroplating; Preferably, the P-side gate line electroplating solution comprises copper sulfate, sulfuric acid, hydrochloric acid and water; Preferably, the mass concentration of copper sulfate in the P-side gate line electroplating solution is 60 g / L to 130 g / L; Preferably, the mass concentration of sulfuric acid in the P-side gate line electroplating solution is 150 g / L to 250 g / L; Preferably, the mass concentration of hydrochloric acid in the P-side gate line electroplating solution is 50ppm to 100ppm; Preferably, the pH of the P-side gate line electroplating solution is 1 to 4.2; Preferably, the plating current density of the P-side gate line electroplating solution is 0.5 A / cm 2 ~2.5A / cm 2 ; Preferably, the plating temperature of the P-side gate line electroplating solution is 20-30° C.; Preferably, the plating time of the P-side gate line electroplating solution is 7 min to 10 min; Preferably, the N-side gate line electroplating solution comprises copper pyrophosphate, potassium pyrophosphate, potassium dihydrogen phosphate and water; Preferably, the mass concentration of copper pyrophosphate in the N-side gate line electroplating solution is 10 g / L to 70 g / L; Preferably, the mass concentration of potassium pyrophosphate in the N-side gate line electroplating solution is 25 g / L to 90 g / L; Preferably, the mass concentration of potassium dihydrogen phosphate in the N-side gate line electroplating solution is 40 g / L to 110 g / L; Preferably, the pH of the N-side gate line electroplating solution is 7 to 10.2; Preferably, the plating current density of the N-side gate line electroplating solution is 0.5 A / cm 2 ~2.5A / cm 2 ; Preferably, the plating temperature of the N-side gate line electroplating solution is 20-30° C.; Preferably, the plating time of the N-side gate line electroplating solution is 7 minutes to 10 minutes.

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