Spraying device, coating equipment, coating method and battery piece

Abstract

The invention provides a spraying device, coating equipment, a coating method and a battery piece, the spraying device comprises a first box body, the first box body is provided with a first containing cavity with an opening in one side, and the first containing cavity is used for containing a plurality of workpieces to be coated which are arranged in a stacked mode; the first box body comprises a first spraying plate opposite to the opening, and the first spraying plate is provided with at least one first spraying hole communicated with the first containing cavity. According to the invention, the plurality of workpieces to be coated are stacked in the first box body, and the processing surfaces of the workpieces to be coated can be exposed out of the opening, so that the workpieces to be coated at the opening can be coated by reaction gas, and meanwhile, the first spraying plate arranged opposite to the opening can input inert gas into the first box body through the first spraying holes; the risk that reaction gas for coating enters the first box body to coat the non-machined surface of the to-be-coated workpiece can be reduced, so that the product reliability of the to-be-coated workpiece is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of coating technologies, and particularly to a spraying device, a coating apparatus, a coating method, and a battery cell. Background Art

[0002] In the prior art, an ALD (Atomic Layer Deposition) process or a CVD (Chemical Vapor Deposition) process is usually adopted to prepare a passivation film on the cutting surface of a battery cell. Since there are grid lines on the surface of the battery cell, there are gaps between battery cells when multiple battery cells are stacked. The reaction gas in the ALD process will penetrate into the gaps and form a passivation film on the surface of the battery cell, resulting in the phenomenon of overcoating. At the same time, since the passivation film is an insulating film and adheres to the grid lines of the battery cell, when the battery cell is made into a battery module, the passivation film isolates the grid lines and the solder tape, causing a virtual soldering process, which further affects the power generation efficiency of the final battery module. Therefore, it is urgent to propose a technical solution to solve the problem of easy overcoating on the battery surface. Summary of the Invention

[0003] The main technical problem to be solved by the present disclosure is to provide a spraying device, a coating apparatus, a coating method, and a battery cell, so as to improve the product reliability of the battery cell.

[0004] To solve the above technical problem, one technical solution adopted by the present disclosure is: to provide a spraying device, the spraying device includes a first box body, the first box body is provided with a first accommodating cavity with an opening on one side, and the first accommodating cavity is used to accommodate a plurality of stacked workpieces to be coated; wherein, the first box body includes a first spraying plate disposed opposite to the opening, and the first spraying plate is provided with at least one first spraying hole communicating with the first accommodating cavity.

[0005] Wherein, the first spraying plate is provided with a first air inlet hole, and the first spraying hole is communicated with the first air inlet hole through a spraying channel.

[0006] Wherein, the number of the first spraying holes is multiple, and the multiple first spraying holes are arranged in multiple rows. The spraying channel includes a first spraying channel and a second spraying channel; wherein, the first spraying holes in the same row are communicated with the same first spraying channel, and the multiple first spraying channels are simultaneously communicated with the first air inlet hole through the second spraying channel, and the extending direction of the second spraying channel intersects with the extending direction of the first spraying channel.

[0007] Among them, the spraying device further includes a second box body, which includes a second bottom plate, two second side plates and a cover plate. The two second side plates are spaced and connected to both sides of the second bottom plate. Among them, at least one of the first box bodies is arranged on the second bottom plate and between two adjacent second side plates. The opening is arranged facing one of the second side plates, and the opening is spaced from the adjacent second side plate to form an air inlet channel between the opening and the second side plate. The cover plate is arranged opposite to the second bottom plate and is arranged between the two second side plates.

[0008] Among them, the second bottom plate is provided with a second air inlet hole, and the first spraying holes on the first spraying plate are communicated with the first air inlet hole and the second air inlet hole in sequence through the spraying channel.

[0009] Among them, the second box body further includes a second spraying plate, which is arranged at the end of the second bottom plate and connects the two second side plates. The surface of the second spraying plate facing the first box body is provided with second spraying holes, and the second spraying holes are communicated with the air inlet channel.

[0010] Among them, the number of the first box bodies is multiple, and the multiple first box bodies are divided into multiple repeating units, and the multiple repeating units are arranged along the extending direction of the second side plate. Among them, each repeating unit includes two first box bodies, and the openings of the two first box bodies are arranged back to back.

[0011] To solve the above technical problems, a technical solution adopted by the present disclosure is to provide a coating device, including the spraying device described above.

[0012] To solve the above technical problems, a technical solution adopted by the present disclosure is to provide a coating method, using the coating device described above. The method includes: stacking multiple workpieces to be coated in the first box body, and the processing surfaces of the workpieces to be coated are exposed at the openings of the first box body; introducing a first gas into the spaces between the stacked workpieces to be coated through the first spraying holes of the first spraying plate to form an air wall extending towards the processing surface; introducing a second gas to deposit and passivate the processing surface exposed at the opening.

[0013] Among them, the second gas includes any one of O 3 or H 2 O, and the first gas includes any one of N 2 or Ar.

[0014] Beneficial effects: In the present disclosure, multiple workpieces to be coated are stacked in the first box body, and the processing surfaces of the workpieces to be coated are exposed at the opening, so as to coat the workpieces to be coated at the opening with reaction gas. At the same time, the first spray plate disposed opposite to the opening can input inert gas into the first box body through the first spray holes, which can reduce the risk that the reaction gas for coating enters the first box body to coat the non-processing surfaces of the workpieces to be coated, thereby improving the product reliability of the workpieces to be coated.

[0015] Taking the workpiece to be coated as a battery cell as an example, the function of coating the processing surface of the workpiece to be coated is described as follows: In industrial applications, it is usually necessary to cut the battery cell into small pieces, which can reduce the resistance loss of the current on the surface of the battery cell, thereby improving the conversion efficiency of the battery cell. However, during the cutting process of a complete battery cell, its cross-section is an unpassivated silicon wafer cross-section, and the recombination rate of the unpassivated edge cross-section is very high, resulting in a 0.2-0.3% reduction in the conversion efficiency of the battery cell, thus having a greater impact on the electrical performance of the battery cell. The open-circuit voltage of the heterojunction HJT solar cell is high, and the conversion efficiency after laser scribing decreases more (usually greater than 0.3%). The reduction in the efficiency of the battery cell caused by laser scribing will directly lead to a reduction in the power of the entire battery module containing the sliced battery cell. Therefore, it is necessary to passivate and coat the cutting surface of the battery cell (i.e., the processing surface of the workpiece to be coated proposed in the present disclosure) by means of edge passivation to reduce or eliminate the power loss caused by the cutting surface damage. Among them, passivation coating refers to forming a passivation film on the cutting surface of the battery cell (i.e., the processing surface of the workpiece to be coated proposed in the present disclosure) by means of deposition, so as to play the role of reducing minority carrier recombination, providing a field passivation effect, and reducing reflectivity.

[0016] Continuing to take the workpiece to be coated as a battery cell as an example, combined with the function of the above passivation coating process on the battery cell, the content of the spray device, coating equipment and coating method of the present disclosure is mainly reflected in the following points:

[0017] 1. Flow field design

[0018] When multiple battery cells in the first box body are stacked, due to the presence of grid line height on the surface of the battery cells, there are relatively wide gaps between the battery cells. Since the passivation deposition reaction needs to be carried out in a vacuum environment, the pressure in the gaps between the battery cells is relatively low. When the second gas flows through the cutting surface of the battery cell (i.e., the processing surface of the workpiece to be coated), because the pressure on the cutting surface is greater than the pressure in the gaps between the battery cells, the second gas easily enters the gaps between the battery cells, thereby depositing aluminum oxide to form a wrap-around coating, which affects the subsequent welding process.

[0019] Therefore, by setting the first box body, which is also a five-sided closed structure, multiple solar cells are stacked inside the first box body, and the cut surfaces of the solar cells are exposed at the opening of the first box body. The first spray plate sprays a first gas onto the solar cells stacked inside the first box body, and the first gas uniformly flows into the first box body at a specific speed and flow rate, so that the first gas can form an air wall in the gaps between the solar cells, that is, the first gas can exert a pressure in the direction of the cut surface of the solar cells, thereby increasing the pressure in the gaps between the solar cells, enabling the first gas to block the second gas flowing over the surface of the solar cells, and forming a no-go zone for the second gas between the stacked solar cells, thereby reducing the risk of bypass plating caused by the second gas entering the gaps between the solar cells and depositing aluminum oxide.

[0020] 2. New gas field design for edge passivation coating application

[0021] For the application requirements of edge passivation coating, mainly for passivation coating of the cut surfaces of solar cells, which is very different from the traditional application of whole-surface passivation. Therefore, to improve the effective utilization rate of the second gas and avoid the second gas appearing in the non-coated area (i.e., the non-cut surface area) of the solar cells, it is necessary to specifically design the entire gas field. Specifically, after placing the first box body in the second box body, an intake channel is formed between the opening of the first box body and the second side plate of the second box body, so that the second gas for edge passivation coating of the cut surface of the solar cells can contact the cut surface of the solar cells from the intake channel, combined with the first gas sprayed by the first spray plate in the first box body, to achieve the design of a new gas field, while achieving passivation coating of the cut surface of the solar cells, a no-go zone for the second gas can also be formed on the non-cut surface of the solar cells, thereby reducing the risk of bypass plating of the solar cells. At the same time, after the second gas and the first gas are aggregated, the aggregated second gas and first gas can be pumped away by setting an air extraction pump to form the entire airflow field required for the edge passivation coating application of the coating equipment.

[0022] 3. Coating equipment design for edge passivation coating application

[0023] In order to increase the production capacity of the edge passivation coating equipment while ensuring that the process performance is not affected, multiple first box bodies can be set in the second box body, and at the same time, the number of second box bodies can be increased to form a multi-layer stack of multiple second box bodies. Preferably, two second box bodies are stacked on top of each other to achieve a control system with multiple independent zones while improving production efficiency.

[0024] 4. The coating process is further optimized to match the edge passivation coating application. The use of a spraying device can achieve the problem of bypass plating during the passivation coating process of the TMA (trimethylaluminum) + H 2 O process. Further, the TMA (trimethylaluminum) + O 3 (ozone) process is preferably used.

[0025] Currently, the mainstream process for edge passivation coating is the alumina process, and the reactants are TMA (trimethylaluminum) and H 2 O (water). Since there are hydrogen bonds between H 2 O molecules, which have weak intermolecular forces, the hydrogen bonds enable water molecules to form cluster structures, resulting in water having high cohesion and surface tension. This hydrogen bond interaction causes water molecules to attract each other, increasing the difficulty of extracting a single water molecule. At the same time, due to the polar structure of water molecules, with the oxygen atom carrying a negative charge and the hydrogen atom carrying a positive charge, there is a strong interaction between water molecules and other polar molecules, further increasing the difficulty of extracting water molecules.

[0026] Therefore, in combination with the above spraying device using the TMA (trimethylaluminum) + H 2 O process for passivation coating, the first gas ejected from the first spray holes of the first spray plate in the first box can reduce or avoid the situation of H 2 O / TMA / O 3 and other reactants entering the gaps between the battery wafers, improving the problem of overcoating during passivation coating using the TMA (trimethylaluminum) + H 2 O process in the prior art.

[0027] Furthermore, in order to extract the reaction gas (i.e., the second gas) entering the second box to a greater extent, it is preferred to use TMA and O 3 as reaction sources for depositing alumina. Because of the high chemical activity and relatively fast decomposition rate of O 3 , O 3 can be more easily extracted compared to H 2 O molecules, further reducing the risk that the reaction gas enters the gaps between the stacked battery wafers and causing overcoating to affect welding of the battery wafers. However, since O 3 has strong oxidizing properties and is likely to corrode the grid lines on the surface of the finished battery wafers, at this time, in combination with the first box, an air flow and pressure towards the cutting surface are applied to the gaps between the battery wafers through the first spray plate in the first box, so that the pressure in the gaps between the battery wafers is greater than or equal to the pressure on the surface of the cutting surface, preventing O 3 from entering the gaps between the battery wafers, that is, it can prevent the formation of an alumina film on the surface due to overcoating and affecting welding, and can also prevent O 3 from entering between the battery wafers and corroding the grid lines.

[0028] 5. Manufacturing process of battery wafers and components

[0029] A process for controlling the edge plating of photovoltaic cells can use conventional devices or the devices of the present disclosure. The devices of the present disclosure refer to that when passivating the edge section of the cells, a gas wall is formed by introducing a first gas into the gap between the cells to prevent a second gas (reaction gas) from entering the gap between the cells, thereby avoiding the formation of edge plating on the front or back of the cells. The general width of the edge plating of conventional cells is generally 3 - 8 mm. The width of the edge plating on the cells prepared by the process of the present disclosure can be controlled within 0.1 - 1 mm (i.e., using H 2 O as an oxidant and cooperating with the devices of the present disclosure for passivation coating). Preferably, the width of the edge plating on the cells can reach below 0.1 mm (i.e., using O 3 as an oxidant and cooperating with conventional devices for passivation coating). More preferably, the width of the edge plating on the cells can reach below 0.01 mm (i.e., using O 3 as an oxidant and cooperating with the devices of the present disclosure for passivation coating), and almost no edge plating can be observed. Thus, by reducing the edge plating situation, the conversion efficiency loss caused by cell cutting in the welded cell module can be reduced, the efficiency of the cell module is improved, and the power generation cost of the module is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0031] Figure 1 is a schematic diagram of the overall structure of the spraying device provided by some embodiments of the present disclosure;

[0032] Figure 2 is Figure 1 the exploded view of the spraying device in

[0033] Figure 3 is a schematic sectional view of the first spraying plate provided by some embodiments of the present disclosure;

[0034] Figure 4 is a schematic diagram of the structure of the first box body placed in the second box body provided by some embodiments of the present disclosure;

[0035] Figure 5 is a schematic spraying diagram of the second gas and the first gas provided by some embodiments of the present disclosure;

[0036] Figure 6 is a schematic diagram of the structure of the first spraying plate communicated with the second bottom plate provided by some embodiments of the present disclosure;

[0037] Figure 7Schematic diagram of spraying the second gas and the first gas provided by other embodiments of the present disclosure;

[0038] Figure 8 Schematic diagram of four independent regions provided by some embodiments of the present disclosure;

[0039] Figure 9 Schematic diagram of the structure after stacking two second boxes provided by some embodiments of the present disclosure;

[0040] Figure 10 Block diagram of the structure of a coating device provided by some embodiments of the present disclosure;

[0041] Figure 11 Flow chart of a coating method provided by some embodiments of the present disclosure;

[0042] Figure 12 The situation of overcoating on the surface of a battery cell after passivation coating using a water process in a conventional device in the prior art;

[0043] Figure 13 The situation of overcoating on the surface of a battery cell after passivation coating using an ozone process provided by some embodiments of the present disclosure. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0045] The terms "first", "second", and "third" in this disclosure are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of this disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. In the embodiments of this disclosure, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0046] Referring to "embodiments" herein means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this disclosure. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0047] In industrial applications, it is usually necessary to cut the solar cells into small pieces to reduce the resistance loss of the current on the surface of the solar cells, thereby improving the conversion efficiency of the solar cells. However, during the cutting process of a complete solar cell, its cross-section is an unpassivated silicon wafer cross-section, and the recombination rate of the unpassivated edge cross-section is very high, resulting in a 0.2 - 0.3% reduction in the conversion efficiency of the solar cell, thus having a greater impact on the electrical performance of the solar cell. For heterojunction HJT solar cells with a high open-circuit voltage, the conversion efficiency decreases even more after laser scribing (usually greater than 0.3%). The reduction in the efficiency of the solar cell caused by laser scribing will directly lead to a reduction in the power of the entire solar cell module including the sliced solar cells. Therefore, it is necessary to passivate and coat the cutting surface of the solar cell by means of edge passivation to reduce or eliminate the power loss caused by the damage to the cutting surface of the solar cell. Among them, passivation coating refers to forming a passivation film on the cutting surface of the solar cell by means of deposition, so as to play a role in reducing minority carrier recombination, providing a field passivation effect, and reducing reflectivity.

[0048] However, due to the gaps between the stacked cells, according to the measurement of the grid line height, the grid line height of a finished cell is 7 - 11 μm, and the gap height between cells is 14 - 22 μm, which is much larger than the reaction source molecules (such as H2O with 0.27 nm). Moreover, since the deposition reaction needs to be carried out in a vacuum environment, the pressure in the gaps between cells is relatively low. When the reaction gas flows through the cut surface of the cells, due to the pressure on the cut surface being greater than the pressure in the gaps between cells, the reaction gas is likely to enter between the cells, resulting in alumina deposition on the non-cut surface of the cells, causing overcoating and affecting the welding process.

[0049] Therefore, to address the above problems, please refer to Figure 1 , in an embodiment of the present disclosure, a spraying device 100 is provided as a carrier for the workpiece 10 to be coated. Similarly, the workpiece 10 to be coated in the present disclosure is a cell, and usually the cell is coated by the method of oxidizing TMA (Trimethyl Aluminum). Therefore, the technical solution of coating the cell with alumina generated by oxidizing TMA will be described in detail in the present disclosure. It can be understood that the use of other reactants is similar. The spraying device 100 of the present disclosure can be arranged in the coating equipment 200 in the reaction chamber where the coating reaction occurs.

[0050] Among them, the present disclosure can introduce the second gas (i.e., the reaction gas, which may include a passivator and an oxidant) into contact with the processing surface 11 (i.e., the cut surface) of the cell, and then an atomic layer deposition (ALD) chemical reaction occurs on the processing surface 11 to generate a coating, such as an alumina coating, a aluminum nitride coating, a silicon oxide coating, etc., to complete the edge passivation coating process of the cell. In other embodiments, a chemical vapor deposition (CVD) chemical reaction can also be used to generate a coating, which is not limited herein.

[0051] Specifically, please continue to refer to Figure 1 , the spraying device 100 includes a first box body 20. The first box body 20 is provided with a first accommodation cavity 22 with an opening 21 on one side. The first accommodation cavity 22 is used to accommodate a plurality of stacked workpieces 10 to be coated. At this time, the first box body 20 stably supports the plurality of stacked workpieces 10 to be coated, so that the processing surface 11 of the workpiece 10 to be coated can be exposed at the opening 21, so that during the coating process, the second gas (i.e., the reaction gas) can directly perform the coating operation on the processing surface 11 at the opening 21, thereby reducing the risk of unnecessary coating of the second gas on the non-processing surface of the workpiece 10 to be coated.

[0052] Please refer to Figure 1 and Figure 2, the first box body 20 includes a first spray plate 23 disposed opposite to the opening 21. The first spray plate 23 is provided with at least one first spray hole 231 communicating with the first accommodation cavity 22, so that during the coating process, a first gas that does not chemically react with the second gas passing through the opening 21 can be sprayed into the first box body 20 through the first spray hole 231. For example, inert gas nitrogen (N 2 ) or argon (A R ), etc., so as to form an air wall in the gap between the workpieces 10 to be coated, increase the internal air pressure in the first box body 20, that is, increase the gap pressure between the workpieces 10 to be coated, or the air wall formed by the first gas can also directly blow out the second gas entering the gap between the workpieces 10 to be coated, forming a restricted area of the second gas on the non-processing surface of the workpieces 10 to be coated, so as to further reduce the risk of the second gas entering the first box body 20 and contacting the non-processing surface of the workpieces 10 to be coated to cause unnecessary coating, and reduce the occurrence of overcoating on the non-processing surface of the workpieces 10 to be coated.

[0053] Stacking a plurality of workpieces 10 to be coated in the first box body 20, and making the processing surface 11 of the workpieces 10 to be coated exposed at the opening 21, so that the workpieces 10 to be coated at the opening 21 can be coated by the second gas (i.e., the reaction gas). At the same time, the first spray plate 23 disposed opposite to the opening 21 can input the first gas (i.e., the inert gas) into the first box body 20 through the first spray hole 231, which can reduce the risk of overcoating caused by the first gas entering the first box body 20 and coating the non-processing surface of the workpieces 10 to be coated, thereby improving the product reliability of the workpieces 10 to be coated.

[0054] In some embodiments, the flow direction of the first gas sprayed into the first box body 20 from the first spray hole 231 is preferably along the transverse direction of each workpiece 10 to be coated, that is, along Figure 1 The third direction Z in is parallel to the upper surface or the lower surface of the workpiece 10 to be coated. The air flow of the second gas (i.e., the reaction gas) sprayed towards the opening 21 is usually along the vertical direction facing the upper surface or the lower surface of the workpiece 10 to be coated (i.e., Figure 1 The second direction Y in), at this time, the extension direction of the air flow of the second gas and the extension direction of the air flow of the first gas are perpendicular to each other. Here, the extension direction of the air flow of the first gas refers to the flow direction of the first gas between the first spray hole 231 and the processing surface 11 of the workpiece 10 to be coated.

[0055] In some other embodiments, the flow direction of the second gas (i.e., the reaction gas) sprayed towards the opening 21 can also be parallel to the extension direction of the upper surface or the lower surface of the workpiece 10 to be coated (i.e., the third direction Z in the figure), that is, the flow extension direction of the second gas is parallel to the flow extension direction of the first gas to achieve countercurrent, which can further prevent the second gas from entering the gaps between the workpieces 10 to be coated. Similarly, the flow extension direction of the first gas herein refers to the flow direction of the first gas between the first spray holes 231 and the processing surface 11 of the workpiece 10 to be coated.

[0056] Please refer to Figure 2 and Figure 3 , in some embodiments, a first air inlet hole 232 is provided at the bottom of the first spray plate 23. The first spray holes 231 communicate with the first air inlet hole 232 through a spray channel 233. The first air inlet hole 232 is used to introduce the first gas to be sprayed into the first box body 20, so that the first spray plate 23 can effectively spray the first gas between a plurality of stacked workpieces 10 to be coated.

[0057] In some embodiments, the number of the first air inlet holes 232 can be set to be multiple. For example, in this embodiment, two first air inlet holes 232 are provided at intervals at the bottom of the first spray plate 23. It can be understood that the specific number of the first air inlet holes 232 can be set according to the size of the first spray plate 23, and no limitation is made herein.

[0058] Please refer to Figure 2 , in some embodiments, the first box body 20 further includes a first bottom plate 24, a top plate 25 and two first side plates 26. Among them, the first bottom plate 24 and the top plate 25 are oppositely arranged along the first direction X, the two first side plates 26 are oppositely arranged along the second direction Y, the first spray plate 23 is arranged between the two first side plates 26, and the first spray plate 23 and the two first side plates 26 enclose between the first bottom plate 24 and the top plate 25. Among them, the opening 21 is formed between the first bottom plate 24, the top plate 25 and the two first side plates 26, that is, the first spray plate 23 and the opening 21 are oppositely arranged along the third direction Z, so that the first gas sprayed by the first spray plate 23 can enter the interior of the first box body 20.

[0059] It can be seen that the first box body 20 is a five-sided closed structure composed of a first bottom plate 24, a top plate 25, two first side plates 26, and a first spraying plate 23. The stacked workpieces 10 to be coated can be placed in the first box body 20, and the processing surface 11 to be coated is ensured to be exposed at the opening 21 to contact the second gas. First spraying holes 231 are uniformly arranged on the first spraying plate 23, and the first gas can uniformly flow out from the first spraying holes 231 at a specific speed and flow rate, flowing into the gaps between the workpieces 10 to be coated to form an air wall. The existence of this air wall can increase the pressure in the gaps between the workpieces 10 to be coated, thereby preventing the second gas near the processing surface 11 of the workpieces 10 to be coated from drilling into the gaps.

[0060] In some embodiments, the first box body 20 is an integrally formed structure, thereby improving the structural strength of the first box body 20.

[0061] In some embodiments, the first bottom plate 24, the top plate 25, the two first side plates 26, and the first spraying plate 23 are fixedly connected by bolts.

[0062] In some embodiments, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other pairwise.

[0063] Please continue to refer to Figure 2 , in some embodiments, positioning protrusions 251 are provided at both ends of the top plate 25 facing the first side plates 26, and positioning grooves 261 are correspondingly provided on the inner side walls of each first side plate 26 facing the other first side plate 26, wherein the positioning protrusions 251 can be inserted into the positioning grooves 261. The positioning grooves 261 enable the positioning protrusions 251 to be smoothly inserted between the two first side plates 26 when the top plate 25 is placed on the two first side plates 26, realizing precise positioning of the position between the top plate 25 and the first side plates 26, and at the same time improving the connection stability between the top plate 25 and the two first side plates 26.

[0064] Please refer to Figure 2 and Figure 4 , in some embodiments, positioning protrusions 251 can also be provided on one side of the top plate 25 facing the first spraying plate 23, and positioning grooves 261 are correspondingly provided on one side of the first spraying plate 23 facing the top plate 25, further improving the structural stability of the first box body 20.

[0065] Please refer to again Figure 2 and Figure 3, in some embodiments, the number of the first spray holes 231 is plural, and the plural first spray holes 231 may be arranged irregularly. Preferably, for example, in this embodiment, the plural first spray holes 231 are arranged in multiple rows, which can achieve a more uniform and comprehensive spraying effect on the workpiece 10 to be coated in the first box body 20. The spray channel 233 includes a first spray channel 2331 and a second spray channel 2332. Among them, the first spray holes 231 in the same row communicate with the same first spray channel 2331, and the plural first spray channels 2331 communicate with the first air inlet hole 232 through the second spray channel 2332 at the same time. The extending direction of the second spray channel 2332 intersects with the extending direction of the first spray channel 2331. Each row of the first spray holes 231 will receive the first gas from the corresponding first spray channel 2331, ensuring the uniformity and consistency of the spraying actions of each row of the first spray holes 231. At the same time, by connecting with the first air inlet hole 232 through one or more second spray channels 2332, the flow path of the first gas can be optimized, and the flow resistance of the first gas can be reduced, thereby improving the spraying efficiency of the first spray plate 23.

[0066] In some embodiments, the extending direction of the first spray channel 2331 is perpendicular to the extending direction of the second spray channel 2332.

[0067] In this embodiment, the first spray plate 23 is provided with 10 rows of mutually parallel first spray channels 2331. The 10 rows of first spray channels 2331 are all arranged in a crosswise manner with two columns of second spray channels 2332, and each second spray channel 2332 corresponds to and communicates with a first air inlet hole 232. It can be understood that the number of the first spray channels 2331 and the number of the second spray channels 2332 can be correspondingly set according to the size of the first spray plate 23, and no limitation is made here.

[0068] Please refer to Figure 2 、 Figure 4 and Figure 5 , in some embodiments, the spraying device 100 further includes a second box body 30. The second box body 30 includes a second bottom plate 31, two second side plates 32 and a cover plate 35 (refer to Figure 9 ), and the two second side plates 32 are spaced and connected to both sides of the second bottom plate 31. The cover plate 35 is disposed opposite to the second bottom plate 31 and is arranged between the two second side plates 32. In this embodiment, the two second side plates 32 are spaced along the third direction Z, and the cover plate 35 is disposed opposite to the second bottom plate 31 along the first direction X.

[0069] Among them, at least one first box body 20 is arranged on the second bottom plate 31 and located between two adjacent second side plates 32. The opening 21 is arranged facing one of the second side plates 32, and the opening 21 is spaced from the adjacent second side plate 32 to form an air inlet channel 33 between the opening 21 and the second side plate 32. The air inlet channel 33 provides a flow space for the second gas (i.e., the reaction gas) to realize the coating operation on the processing surface 11 of the workpiece 10 to be coated at the opening 21.

[0070] Specifically, the air inlet channel 33 between the opening 21 and the second side plate 32 enables a predetermined spraying path to be formed between the first box body 20 and the second box body 30. When coating the processing surface 11 of the workpiece 10 to be coated, after the second gas (i.e., the reaction gas) enters the second box body 30, it can enter the air inlet channel 33 along the preset spraying path.

[0071] The cover plate 35 (see Figure 9 ) is arranged opposite to the second bottom plate 31 and is arranged between the two second side plates 32, so that each second box body 30 can form a closed independent structure. At the same time, the setting of the cover plate 35 can also facilitate the stacking of the two second box bodies 30 in the first direction X. The cover plate 35 of the lower second box body 30 can support the upper second box body 30.

[0072] In some embodiments, the width and shape of the air inlet channel 33 can be set according to actual coating requirements and are not limited herein.

[0073] Please refer to Figure 3 、 Figure 4 and Figure 6 together. In some embodiments, the second bottom plate 31 is provided with a second air inlet hole 311. The first spraying holes 231 on the first spraying plate 23 are sequentially communicated with the first air inlet hole 232 and the second air inlet hole 311 through the spraying channel 233, so that when the first box body 20 is placed in the second box body 30, the first gas (i.e., the inert gas) can smoothly transition from intake to spraying, forming a complete gas flow path to complete the spraying process of the first spraying plate 23.

[0074] It can be understood that the number of the second air inlet holes 311 is the same as the number of the first air inlet holes 232 to achieve one-to-one correspondence.

[0075] Specifically, the first box body 20 loaded with the stacked finished workpieces to be coated 10 is placed in the second box body 30. There is a second air inlet hole 311 on the second box body 30. The first air inlet hole 232 at the bottom of the first spray plate 23 in the first box body 20 is docked with the second air inlet hole 311 on the second box body 30. The first gas (inert gas such as nitrogen or helium) enters the first spray plate 23 in the first box body 20 through the second box body 30, giving an air flow and pressure in the direction of the processing surface 11 of the workpieces to be coated 10 to the gaps between the workpieces to be coated 10 stacked in the first box body 20. When the second gas (i.e., the reaction gas) flows through the processing surface 11 of the workpieces to be coated 10 through the air inlet passage 33 between the second box body 30 and the opening 21 of the first box body 20, since there is no pressure difference between the processing surface 11 and the gaps between the workpieces to be coated 10 and there is an air flow in the direction of the processing surface 11 to be coated, the second gas (i.e., the reaction gas) will not enter the gaps between the workpieces to be coated 10, thereby reducing the risk of the occurrence of the situation of circumferential plating on the workpieces to be coated 10.

[0076] Please refer to Figure 4 and Figure 5 In some embodiments, the second box body 30 further includes a second spray plate 34. The second spray plate 34 is arranged at the end of the second bottom plate 31 and connects the two second side plates 32. The surface of the second spray plate 34 facing the first box body 20 is provided with second spray holes 341. The second spray holes 341 are communicated with the air inlet passage 33 in the second box body 30, so that the second gas (i.e., the reaction gas) corresponding to the workpieces to be coated 10 can enter the second box body 30 through the second spray holes 341 and continue to flow along the air inlet passage 33, so as to spray the second gas (i.e., the reaction gas) on the workpieces to be coated 10 located at the air inlet passage 33 and exposed at the opening 21 position of the first box body 20. The second gas (i.e., the reaction gas) undergoes a passivation coating reaction on the processing surface 11 of the workpieces to be coated 10.

[0077] Please continue to refer to Figure 4 and Figure 5 In some embodiments, nozzles 342 facing the first box body 20 can be arranged at the second spray holes 341 of the second spray plate 34, and the second spray holes 341 are arranged in the nozzles 342. Among them, the nozzles 342 are convexly arranged towards the first box body 20, which can ensure the gas tightness of the second gas sprayed by the nozzles 342 in the second box body 30, and at the same time reduce the risk of flow loss when the second gas is sprayed from the nozzles 342.

[0078] Specifically, the nozzle 342 can be divided into two categories for spraying the second gas (i.e., the reaction gas). One category is for spraying the passivating agent gas jet, and the other category is for spraying the oxidizing agent gas jet. Then, various second gases (i.e., reaction gases) can be sprayed from the corresponding nozzles 342 into the intake passage 33 of the second chamber 30 and fall onto the processing surface 11 of the workpiece 10 to be coated, which is exposed at the opening 21. After the processing surface 11 meets the temperature conditions, multi-level coating reactions can occur between various second gases (i.e., reaction gases) to achieve the coating process of the processing surface 11.

[0079] It can be understood that each nozzle 342 can be connected to an external passivating agent gas source or oxidizing agent gas source through a corresponding passivating agent pipe or oxidizing agent pipe.

[0080] In some embodiments, the second gas (i.e., the reaction gas) ejected from the nozzle 342 includes, but is not limited to, the passivating agent gas and the oxidizing agent gas.

[0081] Please refer to Figure 4 and Figure 7 , in some embodiments, the second spray plate 34 is provided on the connecting second side plate 32. At this time, the second spray plate 34 is disposed opposite to the first spray plate 23 (see Figure 2 ). At this time, the air flow direction of the second gas (i.e., the reaction gas) sprayed toward the opening 21 is parallel to the extension direction of the upper surface or the lower surface of the workpiece 10 to be coated, that is, the air flow extension direction of the second gas is parallel to the air flow extension direction of the first gas to achieve counterflow, which can further prevent the second gas from entering the gaps between the workpieces 10 to be coated.

[0082] Please refer to again Figure 4 and Figure 5 , in some embodiments, an air extraction port (not shown in the figure) opposite to the second spray plate 34 is further provided at the other end of the second chamber 30. The spraying device 100 further includes an air extraction pump (not shown in the figure) connected to the air extraction port. The air extraction pump is used to suck the gas output from the second chamber 30 (i.e., including the second gas ejected from the first spray plate 23 and the first gas ejected from the second spray plate 34) after the second gas (i.e., the reaction gas) and the first gas are aggregated, so as to maintain the air pressure in the second chamber 30 and form the entire air flow field required for the application of the spraying device 100.

[0083] Please continue to refer to Figure 4 and Figure 5, in some embodiments, the number of the first boxes 20 is multiple, and the multiple first boxes 20 are divided into multiple repeating units 40, and the multiple repeating units 40 are arranged along the extending direction of the second side plate 32 (i.e., arranged along the second direction Y). Wherein, each repeating unit 40 includes two first boxes 20, and the openings 21 of the two boxes are arranged in opposite directions (i.e., arranged in opposite directions along the third direction), so as to perform the coating operation on multiple groups of workpieces 10 to be coated in the multiple first boxes 20 at the same time, thereby improving the production efficiency.

[0084] Specifically, in this embodiment, the first box 20 includes five repeating units 40, and the projections of each repeating unit 40 in the extending direction of the second side plate 32 (i.e., the second direction Y) overlap, so that between the first boxes 20 in the same column in the extending direction of the second side plate 32 for each repeating unit 40, the workpieces 10 to be coated in each first box 20 can share the second gas sprayed from the second spray holes 341 on the same second spray plate 34, further improving the production efficiency while realizing the efficient utilization of the second gas.

[0085] Wherein, each repeating unit 40 includes two first boxes 20, and the two first boxes 20 are arranged in opposite directions along the spacing direction of the second side plate 32 (i.e., the third direction Z), so that the two first boxes 20 can perform the spraying operation independently without interference. Correspondingly, two second spray holes 341 arranged at intervals need to be provided on the second spray plate 34 to perform the spraying operation of the reaction gas on the two first boxes 20 arranged side by side, so as to realize the spraying at different air inlet channels 33 in the second box 30, thereby improving the production efficiency.

[0086] It can be understood that the first spray plates 23 in the first boxes 20 in each repeating unit 40 are preferably of the same design, but they can also be of different designs, so as to realize the independent control of spraying the first gas in each first box 20, that is, the designs between each first box 20 in each repeating unit 40 can be different. For example, in one repeating unit 40, the first spray holes 231 on the first spray plate 23 in one first box 20 are regularly arranged, and the first spray holes 231 on the first spray plate 23 in the other first box 20 are irregularly arranged.

[0087] Please refer to Figure 4 , Figure 5 , Figure 8 and Figure 9 , in some embodiments, the number of the second boxes 30 is multiple, and the multiple second boxes 30 can be stacked along the first direction X to perform the coating operation on the workpieces 10 to be coated in the multiple second boxes 30 at the same time, thereby further improving the production efficiency.

[0088] In this embodiment, taking the setting of two second boxes 30 as an example, the two second boxes 30 are stacked along the first direction X. At this time, when observing along the extension direction of the second side plate 32 (i.e., along the second direction Y), the two second boxes 30 are divided into four regions. The four regions are independent of each other and have independent control systems. That is, the first spray plates 23 of the first boxes 20 in each region are independent, and the second spray holes 341 on the second spray plates 34 in the second boxes 30 in each region are also independent.

[0089] Specifically, the meaning that the first spray plates 23 of the first boxes 20 in each region are independent is as follows: During the coating process, the gas flow rate of the first gas in each first spray plate 23 can be adjusted separately, so as to realize the control of the gas wall flow rate of the first gas sprayed from the first spray plates 23 in all the first boxes 20 in the four regions in the first direction X, the second direction Y, and the third direction Z, and ensure the uniformity of the coating of the workpieces 10 to be coated in the four regions.

[0090] The meaning that the second spray holes 341 on the second spray plates 34 in the second boxes 30 in each region are independent of each other is as follows: During the coating process, the second spray holes 341 in each region also correspond to the intake channels 33 in each region, that is, the gas flow rate of the second gas (i.e., the reaction gas) sprayed toward each intake channel 33 can be adjusted separately.

[0091] Please refer to Figure 10 , the present disclosure provides a coating device 200, including the above-mentioned spraying device 100.

[0092] Among them, the coating device 200 mainly provides the second gas, the first gas or other heating and annealing for the workpieces 10 to be coated during the coating passivation process, so as to meet the environmental parameters required by the coating passivation process.

[0093] Please refer to Figure 4 , Figure 5 and Figure 11 , the present disclosure also provides a coating method, using the above-mentioned coating device 200. The coating method includes:

[0094] S300: Stack a plurality of workpieces 10 to be coated in the first box 20, and the processing surface 11 of the workpieces 10 to be coated is exposed at the opening 21 of the first box 20.

[0095] Among them, the first box 20 is a 5-sided closed structure. The workpieces 10 to be coated, especially many pieces of workpieces 10 to be coated, are closely attached to each other, neatly arranged and stacked into a cuboid, so that the processing surfaces 11 of the workpieces 10 to be coated face the same side, and then neatly inserted into the first box 20, leaving the processing surface 11 facing outward at the opening 21, and at the same time, the whole stack of workpieces 10 to be coated is blocked in the first box 20.

[0096] S310: Introduce a first gas through the first spray holes 231 of the first spray plate 23 into the gaps between the stacked workpieces 10 to be coated, forming an air wall extending towards the processing surface 11.

[0097] Among them, the first spray plate 23 sprays the first gas onto the stacked workpieces 10 to be coated in the first box body 20. The first gas uniformly flows into the first box body 20 at a specific speed and flow rate, so that the first gas can form an air wall in the gaps between the workpieces 10 to be coated, that is, the first gas can exert a pressure in the direction of the processing surface 11 of the workpieces 10 to be coated, thereby increasing the pressure in the gaps between the workpieces 10 to be coated.

[0098] S320: Introduce a second gas to deposit and passivate the processing surface 11 exposed at the opening 21.

[0099] Among them, after the first box body 20 is placed in the second box body 30, an air inlet channel 33 is formed between the opening 21 of the first box body 20 and the second side plate 32 of the second box body 30, so that the second gas (i.e., the reaction gas) for edge passivation coating of the processing surface 11 of the workpiece 10 to be coated can be output from the air inlet channel 33 and contact the processing surface 11 of the workpiece 10 to be coated.

[0100] At this time, the first gas ejected in step S310 can block the second gas flowing through the surface of the workpiece 10 to be coated and form a restricted area for the second gas between the stacked workpieces 10 to be coated, thereby reducing the risk of the second gas entering the gaps between the workpieces 10 to be coated and causing bypass plating on the workpiece 10 to be coated.

[0101] It can be understood that the first gas (i.e., the inert gas) is usually in an always-on state. The second gas (i.e., the reaction gas) can be introduced into the second box body 30 after the first gas is introduced into the first box body 20, or can be introduced into the second box body 30 simultaneously when the first gas is introduced into the first box body 20.

[0102] Please refer to Figure 2 、 Figure 4 and Figure 5 , in some embodiments, the second gas includes any one of O 3 (ozone) or H 2 O (water), and the first gas includes any one of N 2 (nitrogen) or Ar (argon). When the coating device 200 performs passivation coating on the workpiece 10 to be coated, after the first box body 20 is placed in the second box body 30, an air inlet channel 33 is formed between the opening 21 of the first box body 20 and the second side plate 32 of the second box body 30. O 3 (ozone) or H 2O(water) is output from the intake passage 33 as an oxidizing agent in the second gas in cooperation with other passivating agents (such as trimethylaluminum (TMA)) to contact the processing surface 11 of the workpiece 10 to be coated at the opening 21 of the first box body 20 for passivation coating.

[0103] The first spray plate 23 of the first box body 20 can spray N 2 (nitrogen) or Ar (argon) as the first gas into the first box body 20. Among them, N 2 (nitrogen) or Ar (argon) is an inert gas and is not likely to react with other substances. This enables the inert first gas to block the second gas flowing over the surface of the workpiece 10 to be coated and form a no-go zone for the second gas in the gap between the stacked workpieces 10 to be coated, thereby reducing the risk of overcoating caused by the second gas entering the gap between the workpieces 10 to be coated.

[0104] Specifically, taking the workpiece 10 to be coated as a battery cell as an example, the coating method will be described in detail:

[0105] Currently, the mainstream process for edge passivation coating is the alumina process, and the reactants are TMA (trimethylaluminum) and H 2 O (water). Since there are hydrogen bonds between H 2 O molecules, which have weak intermolecular forces, the hydrogen bonds enable water molecules to form a cluster structure, resulting in water having relatively high cohesion and surface tension. This hydrogen bond effect causes water molecules to attract each other, increasing the difficulty of separating a single water molecule. At the same time, because water molecules have a polar structure, with the oxygen atom carrying a negative charge and the hydrogen atom carrying a positive charge, there is a strong interaction between water molecules and other polar molecules, further increasing the difficulty of separating water molecules. Combining Figure 12 , currently using a conventional device and using H 2 O as an oxidizing agent to passivate and coat the edges of battery cells, H 2 O molecules can easily enter the gaps between battery cells, causing the problem of overcoating on the front and back of the battery cells, that is, Figure 12 the overcoating width in

[0106] is greater than 3 grid lines on the battery cell (that is, the overcoating width covers 3 grid lines). 2 While through the spray device 100 of the present disclosure, using the TMA (trimethylaluminum) + H 2 O process for passivation coating, the first gas sprayed from the first spray holes 231 of the first spray plate 23 in the first box body 20 can reduce or avoid the situation of H 2 O molecules entering the gaps between battery cells, making the overcoating width value of the coated battery cells much smaller than the overcoating width value generated by the conventional device in the prior art in cooperation with the H 2 O process, thereby improving the problem of using TMA + H in the prior art.2 During the passivation coating process of the O process, the problem of plating around the battery chips occurs.

[0107] Furthermore, in order to extract the second gas (i.e., the reaction gas) entering the second box body 30 to a greater extent, TMA and O are preferably used 3 as reaction sources to deposit aluminum oxide, because O 3 has high chemical activity and a relatively fast decomposition rate, making O 3 easier to be extracted compared to H 2 O molecules. Further reducing the risk that the reaction gas enters the gaps between the stacked battery chips, resulting in plating around the battery chips and affecting welding. However, due to O 3 having strong oxidizing properties, it is easy to corrode the grid lines on the surface of the finished battery chips. At this time, in combination with the first box body 20, an air flow and pressure towards the cutting surface are applied to the gaps between the battery chips through the first spray holes 231 on the first spray plate 23 of the first box body 20, so that the pressure in the gaps between the battery chips is greater than or equal to the pressure on the surface of the cutting surface, preventing the second gas from entering the gaps between the battery chips. That is, it can prevent the formation of an aluminum oxide film around the surface and affect welding, and can also prevent O 3 from entering between the battery chips and corroding the grid lines.

[0108] Therefore, in combination with Figure 13 it can be seen that the above spray device uses the TMA + O 3 process for passivation coating. The first gas sprayed from the first spray holes 231 of the first spray plate 23 in the first box body 20 can reduce or avoid the situation where O 3 enters the gaps between the battery chips, making the plated battery chips hardly show the situation of plating around. That is, Figure 13 the plating width around is less than or equal to 1 grid line on the battery chip, and almost no plating around can be observed. When it is 400 cycle, the plating width around is less than 0.01 mm, which is completely unrecognizable by the naked eye. The above O 3 process can greatly improve the problem of plating around the battery chips during the passivation coating process using the TMA + H 2 O process in the prior art.

[0109] In addition, in combination with the above spray device 100, the present disclosure can adopt the following embodiments to implement the passivation coating process for the workpiece 10 to be coated:

[0110] Embodiment 1: The reaction sources are preferably TMA (trimethylaluminum) and H 2 O (water)

[0111] In the spray device 100 corresponding to Embodiment 1, the first gas sprayed into the first box body 20 from the first spray holes 231, such as N 2(Nitrogen) or the flow direction of Ar (argon) is preferably along the transverse direction of each cell, that is, parallel to the extension direction of the upper or lower surface of the cell, while the second gas sprayed towards the opening 21, that is, TMA (trimethylaluminum) and H 2 The air flow of O (water) is in the vertical direction facing the upper or lower surface of the cell. At this time, the extension direction of the air flow of the second gas and the extension direction of the air flow of the first gas are perpendicular to each other. Here, the extension direction of the air flow of the first gas refers to the flow direction of the first gas between the first spray hole 231 and the processing surface 11 of the workpiece 10 to be coated.

[0112] Example 2: The reaction sources are preferably TMA (trimethylaluminum) and O 3 (ozone)

[0113] In the spraying device 100 corresponding to Example 2, the first gas sprayed into the first box body 20 from the first spray hole 231, such as N 2 (nitrogen) or the flow direction of Ar (argon) is preferably along the transverse direction of each cell, that is, parallel to the extension direction of the upper or lower surface of the cell, while the second gas sprayed towards the opening 21, that is, TMA (trimethylaluminum) and O 3 (ozone) air flow is in the vertical direction facing the upper or lower surface of the cell. At this time, the extension direction of the air flow of the second gas and the extension direction of the air flow of the first gas are perpendicular to each other. Similarly, here, the extension direction of the air flow of the first gas refers to the flow direction of the first gas between the first spray hole 231 and the processing surface 11 of the workpiece 10 to be coated.

[0114] Example 3: The reaction sources are preferably TMA (trimethylaluminum) and H 2 O (water)

[0115] In the spraying device 100 corresponding to Example 3, the first gas sprayed into the first box body 20 from the first spray hole 231, such as N 2 (nitrogen) or the flow direction of Ar (argon) is preferably along the transverse direction of each cell, that is, parallel to the extension direction of the upper or lower surface of the cell. The air flow direction of the second gas sprayed towards the opening 21, that is, TMA (trimethylaluminum) and H 2 O (water) is also parallel to the extension direction of the upper or lower surface of the cell, that is, the extension direction of the air flow of the second gas is parallel to the extension direction of the air flow of the first gas to achieve counterflow, which can further prevent the second gas from entering the gaps between the cells. Similarly, here, the extension direction of the air flow of the first gas refers to the flow direction of the first gas between the first spray hole 231 and the processing surface 11 of the workpiece 10 to be coated.

[0116] Example 4: The reaction sources are preferably TMA (trimethylaluminum) and O 3 (ozone)

[0117] In the spraying device 100 corresponding to the fourth embodiment, the first gas sprayed into the first box body 20 from the first spraying holes 231, such as N 2 (nitrogen) or Ar (argon), preferably flows along the transverse direction of each cell, that is, parallel to the extending direction of the upper surface or the lower surface of the cell, and sprays towards the second gas at the opening 21, that is, the air flow direction of TMA (trimethylaluminum) and O 3 (ozone) is also parallel to the extending direction of the upper surface or the lower surface of the cell, that is, the air flow extending direction of the second gas is parallel to the air flow extending direction of the first gas to achieve countercurrent, which can further prevent the second gas from entering the gaps between the cells. Similarly, the air flow extending direction of the first gas herein refers to the flow direction of the first gas between the first spraying holes 231 and the processing surface 11 of the workpiece 10 to be coated.

[0118] In the above four embodiments, O 3 (ozone) / H 2 O (water) and TMA are used as the second gas to passivate and coat the cutting surface of the cell. At this time, the spraying direction of the second gas can be perpendicular or parallel to the spraying direction of the first gas, and both can solve the technical problem of the cell efficiency loss caused by the generation of overplating on the cut cells while repairing the cutting loss of the cells, thereby improving the conversion efficiency of the cell module.

[0119] The present disclosure also provides a process for controlling the overplating of photovoltaic cells. When passivating the edge section of the cells by using the device of the present disclosure or other conventional devices, a gas wall is formed by introducing the first gas into the gaps between the cells to prevent the second gas (reaction gas) from entering the gaps between the cells, thereby avoiding the formation of overplating on the front or back of the cells.

[0120] The general overplating width of conventional cells is generally 3 - 8 mm. The overplating width on the cells prepared by the process of the present disclosure can be controlled within 0.1 - 1 mm (that is, using H 2 O as the oxidant and cooperating with the device of the present disclosure for passivation coating). Preferably, the overplating width on the cells can reach below 0.1 mm (that is, using O 3 as the oxidant and cooperating with the conventional device for passivation coating). More preferably, the overplating width on the cells can reach below 0.001 mm (that is, using O 3 as the oxidant and cooperating with the device of the present disclosure for passivation coating), and almost no overplating can be observed. Thus, by reducing the overplating situation, the cell module welded can reduce the conversion efficiency loss caused by cell cutting, improve the efficiency of the cell module, and reduce the power generation cost of the module.

[0121] Specifically, Table 1 shows that the cells use the conventional device / the device of the present disclosure, combined with H 2O / O 3 The width of the bypass plating after edge passivation using O as the oxidant. Among them, both the comparative examples and the examples in Table 1 were experimentally carried out by taking the deposition of an alumina passivation film as an example. The conventional device in Table 1 refers to a device without a first spray plate, that is, a device that does not spray the first gas (inert gas) toward the gap between the battery wafers.

[0122] Table 1

[0123] ITEM Process type Device Plating width Comparative example <![CDATA[TMA+H 2 O]]> Conventional device 3 - 8mm Example 1 <![CDATA[TMA+H 2 O]]> The disclosed device 0.1 - 1mm Example 2 <![CDATA[TMA+O 3 > Conventional device <0.1mm Example 3 <![CDATA[TMA+O 3 > The disclosed device <0.01mm

[0124] Comparative Example 1: Using the ALD (Atomic Layer Deposition) process in combination with a conventional device (a device without a first spray plate 23, that is, a device that does not spray an inert gas toward the gap between the battery wafers) for reaction deposition, with TMA (trimethylaluminum) and H 2 O (water) as reactants for pulsed reaction, the TMA pulse time is 0.1 - 10 s, the purge time is 0.1 - 100 s, the H2O pulse time is 0.1 s, the purge time is 0.1 - 100 s, and the process flow rate is 0.1 - 100000 sccm for verification. The gas flow enters the conventional device in a pulsed manner. The width of the bypass plating of the battery wafers in Comparative Example 1 after passivation is 3 - 8 mm, and the bypass plating phenomenon is very serious.

[0125] Example 1: Using the ALD (Atomic Layer Deposition) process in combination with the device of the present disclosure (a device with a first spray plate 23, that is, a device that sprays an inert gas toward the gap between the battery wafers) for reaction deposition, with TMA (trimethylaluminum) and H 2 O (water) as reactants for pulsed reaction, the TMA pulse time is 0.1 - 10 s, the purge time is 0.1 - 100 s, the H2O pulse time is 0.1 s, the purge time is 0.1 - 100 s, and the process flow rate is 0.1 - 100000 sccm for verification. The gas flow enters the device of the present disclosure in a pulsed manner, and the gas wall flow rate formed by the first gas sprayed from the first spray plate 23 is 0.1 - 100000 sccm. The width of the bypass plating of the battery wafers in Example 1 after passivation can be controlled within 0.1 - 1 mm. Compared with Comparative Example 1, the bypass plating width in Example 1 has been significantly improved.

[0126] Example 2: Compared with Example 1, in this example, TMA and O 3 are used as reactants, and a conventional device is used for deposition. The TMA pulse time is 0.1 - 10 s, the purge time is 0.1 - 100 s, the O3 concentration is 0.1 - 50%, and the gas flow enters the conventional device in a pulsed manner. The width of the bypass plating of the battery wafers in Example 2 after passivation can reach less than 0.1 mm, and the bypass plating problem has been further improved compared with Example 1.

[0127] Example 3: Compared with Example 1, the same deposition passivation is carried out using the device of the present disclosure, and TMA and O 3 are used as reactants. The TMA pulse time is 0.1 - 10 s, the purge time is 0.1 - 100 s, the O3 concentration is 0.1 - 50%, and the gas flow enters the device of the present disclosure in a pulsed manner. The wrap-around plating width of the cell after passivation in Example 3 can reach less than 0.01 mm, greatly improving the wrap-around plating problem compared with Example 1.

[0128] As can be seen from Table 1 above, for the cells passivated by the methods of Example 1, Example 2 and Example 3 of the present disclosure, the wrap-around plating width has been significantly improved compared with Comparative Example 1. Therefore, the cell assemblies welded from the cells prepared by the processes of Example 1, Example 2 and Example 3 of the present disclosure can reduce the conversion efficiency loss caused by cell cutting, improve the efficiency of the cell assemblies, and reduce the power generation cost of the assemblies.

[0129] The above is only the implementation mode of the present disclosure, and does not limit the patent scope of the present disclosure. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present disclosure, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present disclosure.

Claims

1. A spray device, characterized in that: The spray device comprises a first box body, the first box body is provided with a first accommodating cavity with an opening on one side, and the first accommodating cavity is used to accommodate a plurality of stacked workpieces to be coated; Wherein, the first box body comprises a first spray plate arranged opposite to the opening, and the first spray plate is provided with at least one first spray hole communicating with the first accommodating cavity.

2. The spray device according to claim 1, characterized in that: The first spray plate is provided with a first air inlet hole, and the first spray hole is communicated with the first air inlet hole through a spray channel.

3. The spray device according to claim 2, characterized in that: The number of the first spray holes is multiple, and the multiple first spray holes are arranged in multiple rows, and the spray channel includes a first spray channel and a second spray channel; The first spray holes in the same row are connected to the same first spray channel, and a plurality of the first spray channels are simultaneously connected to the first air inlet hole through the second spray channel, and an extension direction of the second spray channel intersects with an extension direction of the first spray channel.

4. The spray device according to claim 2, characterized in that: The spray device further includes a second box, wherein the second box includes: Second base plate; Two second side plates are connected to two sides of the second bottom plate at intervals; Wherein, at least one of the first boxes is arranged on the second bottom plate and between two adjacent second side plates, the opening of the first box is arranged toward one of the second side plates, and the opening is spaced apart from the adjacent second side plates to form an air intake passage between the opening and the second side plates; The cover plate is arranged opposite to the second bottom plate and between the two second side plates.

5. The spray device according to claim 4, characterized in that: The second bottom plate is provided with a second air inlet hole, and the first spray hole on the first spray plate is connected with the first air inlet hole and the second air inlet hole in sequence through the spray channel.

6. The spray device according to claim 4, characterized in that: The second housing further comprises: The second spray plate is arranged at the end of the second bottom plate and connects the two second side plates. The surface of the second spray plate facing the first box body is provided with a second spray hole, and the second spray hole is communicated with the air inlet channel.

7. The spray device according to claim 4, characterized in that: There are multiple first boxes, and the multiple first boxes are divided into multiple repeating units. The multiple repeating units are arranged along the extension direction of the second side plate, wherein each of the repeating units includes two first boxes, and the openings of the two first boxes are arranged back to back.

8. A coating device, characterized in that: The spray device comprises the spray device described in any one of claims 1 to 7.

9. A coating method, using the coating device according to claim 8, characterized in that: The method comprises: Stacking a plurality of workpieces to be coated in a first box, wherein the processed surfaces of the workpieces to be coated are exposed at the opening of the first box; Passing a first gas through the first spray hole of the first spray plate into between the stacked workpieces to be coated to form a gas wall extending toward the processing surface; A second gas is introduced to perform deposition passivation on the processing surface exposed at the opening.

10. The method according to claim 9, characterized in that The second gas includes any one of O3 or H2O, and the first gas includes any one of N2 or Ar.

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