A reactor and equipment for passivation coating of battery slice section and working method thereof

Abstract

A reactor and equipment for passivation coating of battery slice section and working method, the reactor includes a reaction chamber, the reaction chamber inner wall surface vicinity, is provided with at least two groups of spray head for passing into oxidizing agent gas and passivation agent gas;Reaction chamber is equipped with carrier for driving carrier box horizontal reciprocating uniform speed translation and passes through the spray head;The battery slice is placed in the open slot of carrier box, and is attached to the inner wall surface of open slot, and the section is towards the spray head, to accept the reaction gas deposition and avoid gas into carrier box;It also includes a heat radiation device, heats the section to reaction temperature, and passivation reaction occurs, and the coating passivation layer is formed on the section.The thickness of the passivation layer of the application can be easily adjusted by the arrangement density of the spray head and / or the translation speed of the carrier box.Even if a small amount of reaction gas enters the carrier box, it cannot deposit a coating on the front or back of the battery slice because it does not reach the reaction temperature, so the coating efficiency is effectively improved and the around-plating is controlled.

Description

Technical Field

[0001] This invention relates primarily to the field of photovoltaic cell technology, specifically to a reactor, equipment, and operating method for passivation coating of cell cross-sections. Background Technology

[0002] Photovoltaic cells are the core component of solar cell modules, and their quality and efficiency directly affect the overall power generation efficiency and lifespan of the solar cell module. Current flows along the surface of a photovoltaic cell, while voltage is generated between the electrodes. When the area of ​​a photovoltaic cell is large, the current flow path is longer, increasing resistance and resulting in energy loss, thus affecting conversion efficiency. Cutting photovoltaic cells to reduce their individual area decreases the resistance and electron travel on the cell surface, thereby improving conversion efficiency. For example, cutting a cell in half and then connecting them in series reduces the current to half its original value. According to Joule's law, Q=I²Rt, the electrical loss due to resistance is reduced to 1 / 4 of its original value. Therefore, cutting photovoltaic cells into smaller pieces reduces the resistance and electron travel on the cell surface, improving the conversion efficiency of the solar cell.

[0003] At the same time, cutting photovoltaic cells can reduce scrap rates, reduce material waste, and thus lower manufacturing costs.

[0004] In addition, dividing large photovoltaic cells into smaller pieces makes them easier to use in different application scenarios and increases the flexibility of solar cell modules.

[0005] Currently, industrial applications typically employ methods for dicing solar cells, such as laser scribing combined with mechanical dicing and thermal laser dicing with low damage. However, dicing the cells results in sectional damage, leading to a high surface recombination rate at the diced surface. This sectional damage causes significant recombination, resulting in power loss and thus significantly impacting the electrical performance of the solar cell. For example, when a Topcon solar cell is diced in half using laser scribing, the conversion efficiency of the half-cell decreases by 0.2-0.3% due to increased sectional recombination. Heterojunction solar cells, with their higher open-circuit voltage, experience even greater efficiency reductions after laser dicing. This efficiency reduction caused by dicing directly leads to a decrease in the overall power output of the module made from the diced cells.

[0006] To reduce or eliminate power loss caused by dicing damage, metal oxide coatings such as aluminum oxide can be used to passivate the damaged areas caused by dicing. Specifically, passivation coating refers to the deposition of a passivation film on the silicon wafer end face of the side dicing of the solar cell, thereby reducing minority carrier recombination, providing field passivation effect, and reducing reflectivity. As the quality of N-type silicon wafers and the efficiency of solar cells continue to improve, the dicing losses are also increasing. Therefore, performing passivation coating on the dicing surface of the solar cell after dicing has become increasingly important.

[0007] Existing passivation coating processes, in order to improve efficiency, typically involve stacking multiple solar cells, placing them in a passivation zone, and then introducing reactants and carrier gas through a gas path system into the passivation zone. The reactants and carrier gas are deposited on the side cut surfaces of the solar cells, forming a passivation film at the reaction temperature. However, the height of the metal grid lines on the front and back sides of the printed solar cells is usually 10-30 micrometers, resulting in gaps between the stacked cells. During coating, the passivation repair film can extend into these gaps; this phenomenon is called wrap-around coating. When the wrap-around coating is deposited onto the solder joints on the front and back sides of the solar cells, it can lead to poor contact, affecting the yield of the final solar module. Performing coating only on a single solar cell is too inefficient.

[0008] It is evident that the current process of coating cells after slicing batteries still has significant shortcomings. Therefore, existing technologies require further improvement and enhancement. Summary of the Invention

[0009] In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a reactor, equipment and working method for passivation coating of battery cell cross-sections, so as to solve the technical problem of possible slack coating when passivating coating of battery cell cross-sections in the present art.

[0010] The technical solution of the present invention is as follows:

[0011] This invention first discloses a reactor for passivation coating of battery cell cross-sections, comprising:

[0012] A reaction chamber for accommodating the coating reaction, wherein at least two sets of nozzles are disposed near the inner wall of the reaction chamber; within the reaction chamber, a carrier for driving a substrate containing battery cells to translate past the nozzles is disposed; wherein

[0013] The substrate holder has an opening slot on the side facing the nozzle, through which the battery cells are placed into the substrate holder; the battery cells are placed close together, with the outermost battery cell in contact with the inner wall of the opening slot; the cut surface of the battery cell to be coated faces the nozzle.

[0014] The nozzle includes a first nozzle and a second nozzle, which are respectively used to spray an oxidant gas jet and a passivator gas jet into the reaction chamber;

[0015] It also includes a thermal radiation device for heating the cut surface to the reaction temperature;

[0016] The translation is a horizontal reciprocating uniform motion.

[0017] This invention comprises a reaction chamber equipped with various nozzles and a carrier capable of translating a wafer cassette. The wafer cassette contains up to 100-10000 solar cells. During translation, the cut surfaces of the solar cells are kept facing the nozzles, i.e., the normal direction of the cut surfaces is parallel to the spray direction of the nozzles. Thus, the cut surfaces sequentially receive passivating agent jets and oxidizing agent jets from different nozzles during the movement. Furthermore, a thermal radiation device heats the cut surfaces to the reaction temperature, causing atomic layer deposition (ALD) to occur on the cut surfaces, forming a passivation layer. The thickness of the passivation layer can be easily adjusted by the nozzle arrangement density and / or the translation speed of the cut surfaces. Because the solar cells are bonded together, and the outer solar cells are bonded to the inner wall of the opening groove, it is difficult for the oxidant gas jet and passivator gas jet to enter the substrate container. Even if a small amount of reactive gas enters the substrate container, it cannot reach the reaction temperature and therefore cannot deposit a coating on the front and back sides of the solar cells. Thus, the technical solution of this invention effectively improves the coating efficiency and controls the occurrence of wrap-around coating. The horizontal and uniform movement of the cut surface ensures that the reactive gas received on the cut surface is not subjected to additional acceleration forces that could drive the reactive gas to aggregate or disperse in the direction of movement as it moves with the cut surface. This ensures that the generated coating thickness is consistent in the direction of movement.

[0018] In one embodiment, the oxidant is water vapor / ozone, and the passivating agent is TMA. TMA, or trimethylaluminum, has a boiling point of 126°C at atmospheric pressure. It reacts with ozone and water to form aluminum oxide (Al₂O₃), which is deposited on a solid surface, such as the cut surface, to create a dense passivation layer. Both the passivating agent and the oxidant enter the reaction chamber in a gaseous state and sequentially contact the traveling and exposed cut surface. Upon reaching the reaction temperature, an atomic layer deposition (ALD) chemical reaction occurs, generating an aluminum oxide passivation coating.

[0019] Preferably, a synchronization mechanism is also included to drive the thermal radiation device to maintain its radiant heat towards the cross-section. The thermal radiation device can be, for example, an infrared spotlight. Because the solar cell is translating, a synchronization mechanism is provided, such as a trolley that moves synchronously with the carrier, carries the thermal radiation device, and moves with the cell cassette, while maintaining the thermal radiation direction of the device always towards the cross-section. The synchronization mechanism helps to further limit heating to only the cross-section, thereby preventing the coating reaction from occurring on other parts of the solar cell. The synchronization mechanism can also be a probe and motor that control the rotation of the thermal radiation device to maintain its radiant heat always towards the translating cross-section.

[0020] Preferably, multiple nozzles are provided, dispersedly embedded in or suspended on the inner top surface or opposite side surfaces of the reaction chamber, with the spray direction of each nozzle perpendicular to the translational direction of the substrate cassette. By dispersing the nozzles and maintaining the spray direction perpendicular to the translational direction of the substrate, the cut surface sequentially receives oxidant and passivating agent jets during movement. Simultaneously, because the time for receiving the gas is short, and the time spent passing through each nozzle is essentially the same, the passivation layer on the cut surface is very thin and uniform. Furthermore, providing multiple nozzles to cover the entire length of the cut surface further ensures consistent coating throughout the cut surface.

[0021] More preferably, the nozzle includes at least one row of first nozzles and at least one row of second nozzles arranged alternately and parallel to the length direction of the cut surface. By arranging the entire row of nozzles parallel to the length direction of the cut surface, when the cut surface is translated, all portions along the length direction of the cut surface simultaneously face and pass through the same row of nozzles, receiving an equal amount of reaction reagent, which helps to generate a uniform coating along the length direction of the cut surface. Furthermore, more preferably, the first nozzles and the second nozzles are separated by a predetermined distance, for example, about 6 cm, specifically determined by the jet velocity, the air pressure in the reaction chamber, and the vertical distance from the nozzle to the cut surface. This ensures that the jets ejected from the nozzles do not meet in the air before landing on the cut surface, thus preventing oxidation reactions that could lead to the formation of metal oxide particles, such as aluminum oxide particles, which would then fall onto the cut surface and affect the coating quality.

[0022] In one embodiment, the system further includes a first branch pipe and a second branch pipe arranged in parallel and staggered configurations. The first nozzles are distributed along the length of the first branch pipe and open onto it, and the second nozzles are distributed along the length of the second branch pipe and open onto it. Each first branch pipe is connected to an external passivating agent / oxidizing agent gas source via a first main pipe, and each second branch pipe is connected to an external oxidizing agent / passivating agent gas source via a second main pipe. At least a portion of the first and second main pipes is disposed on the outer surface of the reaction chamber. The parallel and staggered arrangement of the first and second branch pipes, connected to an external gas source via the first and second main pipes, means that each branch pipe is connected to the main pipe in a centipede-like manner, delivering gas from the external gas source to each nozzle for ejection. This method helps ensure that the ejected materials from each nozzle have very similar physicochemical parameters, thereby further ensuring the uniformity of the coating. Meanwhile, the hierarchical arrangement of the main pipe and branch pipes helps to simplify the design and manufacturing of the entire reactor, and facilitates maintenance by replacing blocked / damaged branch pipes, or by adding or removing branch pipes to change the number and thickness of coating layers.

[0023] In one embodiment, the carrier is a row of horizontally placed parallel rollers, and the substrate cassette is placed horizontally on the rollers, with the gap between two adjacent rollers being less than half the length of the substrate cassette. In this case, the nozzle can be positioned near the inner top surface of the reaction chamber, spraying a jet of reactive gas downwards. As the substrate cassette passes below the nozzle, each upward-facing cut surface sequentially receives the passivating agent gas flow and the oxidizing agent gas flow, thereby depositing an alumina passivation layer on the cut surface. Alternatively, the nozzle can be positioned near the left and right inner walls of the reaction chamber, perpendicular to the direction of movement of the substrate cassette, spraying a jet of reactive gas horizontally, with each cut surface facing the left and right inner walls on the same side. Furthermore, by controlling the gap between the rollers, the substrate cassette is always supported by at least two rollers below during movement, thus ensuring translational stability. This translational stability ensures that the distance between the cut surface and the nozzle remains constant, keeping the jet diffusion width constant. Therefore, the reactant concentration at the contact point between the jet and the cut surface remains constant, ensuring the uniformity of the coating along the length of the cut surface.

[0024] Preferably, the system further includes a carrier tray placed on the roller and driven to move by the roller; the substrate cassette is placed on the carrier tray. The carrier tray, with its larger base area, allows multiple substrate cassettes to be placed simultaneously and moved together. Furthermore, placing the substrate cassettes on a larger carrier tray, allowing them to contact more rollers, further ensures the stability of the substrate cassette movement. Simultaneously, the carrier tray allows for the arrangement of substrate cassette arrays at different heights in a three-dimensional manner, ensuring all cut surfaces face the nozzles on the inner walls of the left and right sides, forming a two-dimensional substrate cassette matrix, thereby accommodating more substrate cassettes and improving coating efficiency.

[0025] In another embodiment, the carrier is a horizontally placed conveyor belt, the slide box is placed on the conveyor belt or suspended below the conveyor belt, and the nozzles are disposed on the inner walls of the left and right sides of the reaction chamber. A conveyor belt is provided, and the slide box is placed above or below the conveyor belt, with its cut surface facing the two sides of the reaction chamber parallel to the direction of movement. The nozzles are also disposed on these two sides. This ensures that the cut surface receives the oxidant and passivating agent sequentially fed from the nozzles during movement, resulting in a passivation reaction.

[0026] Preferably, the system also includes a suction tube for drawing in gas to maintain a low pressure inside the reaction chamber. Lowering the gas pressure inside the reaction chamber, for example, to only a few tens of Pascals, helps reduce the diffusion of the jet ejected from the nozzle, preventing the jet from mixing and reacting chemically before contacting the cut surface, thus avoiding the formation of oxide solid particles that fall onto the cut surface and affect the density of the coating. Simultaneously, lowering the gas density inside the reaction chamber also helps prevent the temperature inside the reaction chamber from rising to the reaction temperature.

[0027] In one embodiment, the wafer carrier cassette is further provided with gas nozzles for injecting gas into the cassette. The wafer carrier cassette can be made of, for example, aluminum alloy, with the opening groove formed on, for example, the upper end face, and the gas nozzles formed on the lower end face or side face, connected to an external gas source via a flexible hose or telescopic tube. During operation, gas is injected into the wafer carrier cassette through the gas nozzles, and the gas does not react with oxidants and passivators, such as chemically inert gases like nitrogen or argon. The gas nozzles are preferably located on the left and right side walls of the wafer carrier cassette in the translational direction, spraying gas towards the space between the solar cells, blowing away the reacting gas that has entered from the cut surface of the solar cells to the side of the solar cells. In this way, by maintaining a certain higher gas pressure inside the wafer carrier cassette, oxidant and passivator gases can be prevented from entering the wafer carrier cassette, further preventing the deposition of oxidants and passivators on the front or back of the solar cells, and further reducing the possibility of plating around the surface.

[0028] The present invention also discloses a method for operating the reactor used for passivation coating of battery cell cross-sections, comprising:

[0029] a. Place the substrate containing the battery cells onto the carrier, with the cut surface facing the nozzle;

[0030] b. The carrier drives the slide box to translate;

[0031] c. The nozzle sprays an oxidizing gas jet and a passivating gas jet onto the cut surface;

[0032] d. The thermal radiation device heats the cut surface to the reaction temperature;

[0033] Steps b, c, and d occur simultaneously throughout the entire reaction process.

[0034] The technical solution of this invention involves first placing a wafer carrier onto a support when the reaction chamber is opened. Depending on the support, this can be done by horizontal placement or vertical suspension. Because the solar cells are tightly attached to each other and the opening is sealed, the passivating agent gas and oxidizing agent gas cannot enter the wafer carrier. Simultaneously, because only the cut surface is heated to the reaction temperature, deposition reactions on the front or back of the solar cells are prevented, thus avoiding plating around the surface. When the temperature of the cut surface reaches the reaction temperature (150-250°C), an ALD reaction occurs on the cut surface, generating a deposit and forming a robust passivation film.

[0035] Preferably, the translation is a horizontal reciprocating uniform motion. Considering that the nozzles are preferably arranged in multiple rows along the inner wall of the reaction chamber, this horizontal reciprocating motion ensures that the cut surface always passes each nozzle at approximately the same distance, thus guaranteeing that the cut surface receives approximately the same amount of passivating agent and oxidizing agent gas sequentially, resulting in a coating of approximately the same thickness. Simultaneously, the reciprocating motion also helps to reduce the length of the reaction chamber. Uniform motion avoids the ALD reactants being disturbed by acceleration, preventing uneven coating thickness along the translational direction. Therefore, reducing disturbance to the ALD reaction further contributes to the formation of a uniform and dense coating.

[0036] This invention also discloses an apparatus for passivation coating of battery cell cross-sections, comprising any of the reactors described above, a gas path for supplying reaction gas to the nozzles, and a power device for driving the carrier. The reactor is disposed within the apparatus, and the gas path can be located outside the reaction chamber, with one end connected to an external passivating agent gas source or oxidizing agent gas source, and the other end connected to each nozzle. The carrier is driven by the power device; for example, a motor drives gears to rotate, and the rotation is transmitted via a belt to a conveyor belt or roller, which then translates the carrier, driving the wafer cassette to move horizontally.

[0037] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the reactor used for passivation coating of battery cell sections according to the present invention;

[0039] Figure 2 This is a schematic diagram of the specific structure of the slide box in this invention;

[0040] Figure 3This is a schematic diagram of the specific arrangement of nozzles disposed on the inner wall of the reaction chamber in one embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the specific arrangement of gas passages disposed on the inner wall of the reaction chamber in one embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the overall structure of another embodiment of the reactor in this invention;

[0043] In the diagram: 10-Reaction chamber; 11-Oxidizing agent tube; 110-First nozzle; 111-First branch pipe; 112-First main pipe; 12-Passivating agent tube; 120-Second nozzle; 121-Second branch pipe; 122-Second main pipe; 13-Roller; 130-Conveyor belt; 14-Suction pipe; 15-Motor; 16-Carrier tray; 20-Carrier box; 21-Opening slot; 22-Battery cell; 23-Cut surface; 25-Gas nozzle. Detailed Implementation

[0044] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0045] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element present. The terms "vertical," "positive," "negative," and similar expressions used herein are based on the orientation or positional relationship shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains, and the terminology used herein in the description of the invention is for the purpose of describing particular embodiments and is not intended to limit the invention.

[0048] The reactor of the present invention is used for passivation coating of battery cell cut surfaces, for depositing coatings on the exposed cut surfaces of cut battery cells. Typically, TMA oxidation is commonly used for silicon wafer coating. Here, the technical solution of the present invention is described in detail using TMA oxidation to generate aluminum oxide for silicon wafer coating as an example. The overall structure of one embodiment of the reactor of the present invention is as follows: Figure 1 As shown, it includes a reaction chamber 10 for accommodating the coating reaction, at least two sets of nozzles disposed on or suspended near the inner wall of the reaction chamber, and an oxidant pipe 11 and a passivating agent pipe 12 disposed outside the reaction chamber 10. The oxidant pipe 11 and the passivating agent pipe 12 are used to introduce oxidant gas or passivating agent gas into each set of nozzles, respectively.

[0049] In a preferred embodiment, a suction pipe 14 is also included, connected to an external vacuum pump, for evacuating the gas inside the reaction chamber 10 to maintain a near-vacuum low pressure of about 10-100 Pascals inside the reaction chamber.

[0050] Within the reaction chamber 10, a carrier is provided for driving the battery cell 22 to be coated to move and pass through the nozzle, for example... Figure 1 In this embodiment, the battery cell 22 is loaded in a carrier box 20 with the cut surface 23 facing outwards. The carrier box 20 is placed on a row of rollers 13. Under the drive of a driving device, such as a motor 15 and a conveyor belt, all rollers 13 rotate simultaneously in the same direction, pushing the carrier box 20 placed on the rollers 13 to translate in the same direction. When passing through each set of nozzles, the exposed cut surface 23 of the carrier box 20 receives the oxidant gas or passivating gas sprayed by each nozzle in sequence. When the carrier box 20 is close to the wall, the rollers 13 rotate in the opposite direction. That is, the carrier drives the carrier box 20 and the battery cell 22 it carries to move back and forth along the plane, passing through each set of nozzles in sequence, and the cut surface 23 receives the oxidant gas and passivating gas in sequence. Then, a heating device heats the cut surface 23 to the reaction temperature, and the reaction gas deposited on the cut surface 23 undergoes an ALD coating reaction.

[0051] Considering that the interior of the reaction chamber 10 is close to a vacuum, the heating device is a thermal radiation device, including a thermal radiation disk for radiating heat to the cut surface 23, such as an infrared heater that emits light towards the cut surface 23. Using a thermal radiation device ensures that only the cut surface 23 on the battery cell 22 receives thermal radiation and is heated to the reaction temperature. Other parts of the battery cell 22, because they are not exposed to thermal radiation, do not reach the reaction temperature. Therefore, even if a small amount of reactant falls onto the front or back of the battery cell 22 due to the presence of the grid lines, a coating reaction cannot occur, thus preventing coating around the surface. Considering that the cut surface 23 faces the nozzle to receive the reaction gas ejected from the nozzle, the thermal radiation device can be a thermal radiation disk placed on the inner wall behind the nozzle, especially multiple small thermal radiation disks dispersed between the nozzles to avoid the nozzles blocking the thermal radiation. Of course, considering the continuity of the coating reaction and the fact that the cut surface 23 is moving, even if it passes the nozzle and is blocked from receiving heat radiation, the temperature on the cut surface 23 will not drop immediately, and the coating reaction will continue. Furthermore, because the nozzle is very small, the time it blocks heat radiation is very short and will not affect the coating reaction. Even if the coating reaction pauses temporarily due to insufficient temperature, it will continue to receive heat as the cut surface 23 moves between the nozzles, allowing the coating reaction to continue.

[0052] In a preferred embodiment, the thermal radiation device further includes a synchronization mechanism for driving the device to track the movement / rotation of the slide cassette 20. This synchronization mechanism can be, for example, a probe controlling the rotation of the thermal radiation disk to ensure it always radiates light and heat towards the translating cut surface 23; or it can be a trolley that moves synchronously with the slide cassette 20, carrying the thermal radiation disk and translating synchronously with it, ensuring the disk always radiates heat towards the cut surface 23. Specifically, for example, the trolley is also located within the reaction chamber 10, placed on the roller 13, but outside the spray range of all nozzles to prevent obstruction of the reactive gas jet. The trolley is physically connected to the slide cassette 20, such as by a connecting rod, and the thermal radiation disk is placed on the trolley and tilted towards the cut surface 23. This achieves synchronous movement of the thermal radiation disk and the slide cassette 20.

[0053] The specific structure of the slide box 20 is as follows: Figure 2As shown, one side of the wafer carrier 20 has an opening slot 21. The battery cells 22 are stacked and inserted into the opening slot 21. Because the battery cells 22 are very thin, approximately 120 micrometers thick, they are usually inserted in one stack at a time, such as 100-1000 cells, with a thickness of 12 mm-12 cm. They are stacked into a cuboid, ensuring the cut surfaces 23 to be coated face in the same direction, especially on the same plane, and the protruding grid lines on the front and back of each battery cell are tightly abutted against each other. The cuboid battery cells 22 are then neatly inserted into the opening slot 21, leaving the cut surfaces 23 exposed and facing outwards. The battery cells 22 are also tightly abutted against each other, with the outermost layer abutting against the inner wall of the opening slot 21. Typically, the opening slot 21 can be an entire wall of the wafer carrier 20, so that when the neatly arranged battery cells 22 are inserted, the battery cells 22 on both sides are tightly abutted against the inner wall of the wafer carrier 20 on either side in the direction of movement, with their front or back sides against the inner wall of the wafer carrier 20. In a preferred embodiment, the opening size of the slot 21 is adjustable by means of a structure such as a spring to adapt to the actual thickness of the stacked battery cells 22 and change the opening size in real time. In particular, the size of the entire battery cell 20 is changed by moving one of the front or rear walls of the battery cell 20, so that the front and rear inner walls of the battery cell 20 always remain in close contact with the front or back of the two outermost battery cells 22. In a preferred embodiment, a gas nozzle 25 is provided on the wall surface, preferably on the side wall, of the substrate cassette 20, connected to a flexible hose / telescopic tube. This nozzle continuously injects a chemically inert gas that will not react with the reactive gas into the substrate cassette 20. This dispels any small amount of oxidizing and / or passivating gas that may enter the substrate cassette 20 through gaps formed by grid lines at different locations. These gaps include those between the inner wall of the opening groove 21 and the side surface of the solar cell 22, and between the side surfaces of two adjacent solar cells 22. These gaps are formed because the side surfaces of adjacent solar cells 22 cannot be completely fitted together due to the presence of grid lines, etc. Maintaining a certain amount of gas flow between the side surfaces of the solar cells 22 also helps cool the front and back sides of the solar cells, especially the side surfaces of the solar cells 22 near the cut surface 23. This further prevents plating around the front or back of the solar cells 22. It should be noted that the gas injected into the substrate cassette 20 from the gas nozzle 25 preferably flows in the transverse direction of the battery cell 22, that is, parallel to the length direction of the cut surface 23. The reactive gas injected from each nozzle flows perpendicular to the cut surface 23. This ensures that the two gas flows are as perpendicular as possible to each other, avoiding airflow collision and minimizing interference with the coating reaction that occurs after the reactive gas flows contact the cut surface 23 and heat up. Alternatively, a smaller gas flow rate from the gas nozzle 25 can also reduce this interference. The substrate cassette 20 with the battery cell 22 placed can then be placed on the carrier within the reaction chamber 10 and reciprocated by the carrier. In one embodiment, the carrier can be... Figure 1 The slide cassette 20 consists of multiple rollers 13 placed side by side. To ensure the smooth movement of the slide cassette 20, it must maintain contact with at least two rollers 13 simultaneously during movement, meaning the distance between two adjacent rollers 13 should be less than half the length of the bottom of the slide cassette 20.

[0054] In a preferred embodiment, a carrier tray 16 with a larger base area can be added and placed on the multiple rollers 13. Smaller wafer cassettes 20 are arranged in an array on the carrier tray 16, with the cut surfaces 23 of the solar cells 22 to be coated exposed, and the cut surfaces 23 perpendicular to the spray direction of the nozzles mounted on the wall of the reaction chamber 10. Thus, when the carrier tray 16 is driven to move, it carries the multiple wafer cassettes 20 placed on it back and forth. At this time, because the wafer cassettes 20 lie flat on the rollers 13, and the solar cells 22 stand upright in the wafer cassettes 20, with the cut surfaces 23 facing upwards, each nozzle is installed or suspended near the inner side of the top cover above the reaction chamber 10. The cut surfaces 23 can thus always face the spray direction of the nozzles, passing sequentially through each group of nozzles and receiving the oxidant gas and passivating agent gas input from each nozzle. By setting up a carrier tray 16, the number of rollers 13 that simultaneously contact and support the tray below is increased through a larger bottom area, which further ensures the stability of the movement of the substrate cassette 20, thereby ensuring that the thickness of each coating layer on the cut surface 23 is consistent and the uniformity of each coating layer is achieved.

[0055] Of course, the carrier can also adopt any transmission method commonly found in the prior art, such as a conveyor belt, as long as it can drive the slide box 20 to move stably and the cut surface 23 to maintain a stable orientation.

[0056] In a preferred embodiment, such as Figure 3 As shown, the nozzles are divided into two types: a first nozzle 110 connected to an external oxidant tube 11; and a second nozzle 120 connected to an external passivating agent tube 12. More preferably, each type of nozzle comprises multiple nozzles, arranged in an array: each row of first nozzles 110 and each row of second nozzles 120 are arranged parallel to each other, with a spacing of, for example, 2-10 cm. This allows the ejected gas to alternately contact the moving battery cell 22, depositing onto the cut surface 23 to be coated. At the reaction temperature, atomic layer deposition (ALD) occurs, forming a coating, such as an alumina coating. The distance between the first nozzle 110 and the second nozzle 120 is... dTherefore, there is a certain distance between the oxidant gas and passivating agent gas ejected from the two sets of nozzles, avoiding direct reaction between the two gases in the air. The nozzle's spray direction is set perpendicular to the carrier's translation direction, so that the cut surface 23 facing the nozzle can sequentially pass through each row of nozzles and receive the gas ejected from them. Furthermore, the two sets of nozzles are distributed and repeatedly arranged along the entire translation path of the substrate cassette 20 to ensure sufficient deposition / coating thickness.

[0057] The two types of nozzles are connected to their respective two gas paths, each of which includes a main path and a branch path. At least one section of the main path is disposed on the outer surface of the reaction chamber 10 for connecting to an external gas source, including an oxidizing agent gas such as ozone or water, and a passivating agent source gas such as TMA. One end of each branch path connects to the main path, particularly in a centipede-like parallel arrangement, while the other end connects to each nozzle. This allows external reaction gases to be delivered into the reaction chamber 10 through each nozzle. In a preferred embodiment, the battery cell 22 is kept parallel to each branch path, and during movement, each part of the cut surface 23 moves simultaneously to face each branch path, thereby ensuring uniform coating along the length of the branch path. In a specific embodiment, such as Figure 4 As shown, each row of first nozzles 110 is arranged along the length of the first branch pipe 111, and each row of second nozzles 120 is also arranged along the length of the second branch pipe 121; each first branch pipe 111 is connected to the side of the first main pipe 112 in a roughly parallel and vertical manner, and each second branch pipe 121 is also connected to the side of the second main pipe 122 in a roughly parallel and vertical manner, forming a centipede-leg-shaped structure in the overall air passage.

[0058] In another embodiment of the invention, such as Figure 5 As shown, the carrier is selected as a conveyor belt 130, and the conveyor belt 130 can be positioned above or below the reaction chamber 10. When the conveyor belt 130 is positioned above the reaction chamber 10, the slide cassette 20 moves directly or suspended below the conveyor belt 130 via the carrier tray 16. When the conveyor belt 130 is positioned below the reaction chamber 10, the slide cassette 20 can be placed directly on or on the conveyor belt 130 via the carrier tray 16, and moves along with it. Figure 5 An embodiment is shown in which the conveyor belt 130 is placed below the reaction chamber 10. In this case, because the multiple slide cassettes 20 are arranged vertically, the openings of the slide cassettes 20 face the side walls of the reaction chamber 10, and correspondingly, the cut surface 23 also faces the side walls. Thus, the nozzles are positioned on the side walls, as shown... Figure 5As shown. At this time, two conveyor belts 130 can be set on the corresponding two side walls. On each conveyor belt 130, a vertically placed tray 16 is set, and multiple wafer trays 20 are arranged in an array on the tray 16. Similarly, the cut surface 23 of the battery cell 22 in each wafer tray 20 faces the nozzle on the left or right side wall.

[0059] Oxidizing gases such as ozone or water vapor and passivating gases such as TMA are sprayed onto the surface of the cut surface 23. At the reaction temperature, oxygen atom layers and aluminum atom layers are alternately formed on the surface of the cut surface 23, ultimately forming an aluminum oxide passivation layer, thus achieving the coating. For example, after ozone and TMA gases are sent into the reaction chamber 10 through their respective nozzles, the temperature of the cut surface 23 is raised to above the reaction temperature by a heating device, which will cause a chemical coating reaction to occur, depositing aluminum oxide on the cut surface 23 to achieve a passivation coating.

[0060] In one specific embodiment of the present invention, the passivating agent is TMA, the oxidizing agent is ozone or water vapor, and the nozzle has a circular opening with a diameter of 0.5-1 mm. A first main pipe 112 is disposed in the middle of the width direction of the reaction chamber 10, and two second main pipes 122 are disposed at both ends of the width direction. All three main pipes extend parallel to each other along the length direction of the reaction chamber 10. The left and right sides of the first main pipe 112 are parallel to the top surface and are vertically connected to multiple rows of first branch pipes 111. The distance between each first nozzle 110 on the first branch pipe 111 is several millimeters, for example, 4 millimeters, to ensure that the jet is uniform throughout the length of the cross-section 23. The side of the second main pipe 122, facing the first main pipe 112, is also parallel to the top surface and is vertically connected to multiple rows of second branch pipes 121. The distance between each second nozzle 120 on the second branch pipe 121 is also several millimeters, for example, 4 millimeters. In order to ensure that the jets ejected from the nozzles on adjacent branch pipes do not meet in the air, the distance between each group of first branch pipes 111 and second branch pipes 121 is relatively large, for example, 10 times the distance between adjacent nozzles on the same branch pipe, for example, 4 centimeters. Furthermore, each first nozzle 110 on the first branch pipe 111 and each second nozzle 120 on the second branch pipe 121 are configured in a one-to-one correspondence, meaning the line connecting the corresponding two nozzles is parallel to the main pipe. In this case, the translation direction of the slide container 20 is along the main pipe. Considering the thickness of the deposited layer, the translation speed of the slide container 20 will not be too high, for example, 5-20 cm / s. Thus, the total flow rate of the first nozzle 110, i.e., the water vapor or ozone flow rate in the oxidant pipe 11, can exceed 2 liters per second; the total flow rate of the second nozzle 120, i.e., the TMA flow rate in the passivating agent pipe 12, also exceeds 2 liters per second.

[0061] In this embodiment, the first nozzle 110 and the second nozzle 120 are selected to be connected to the oxidant source and the passivating agent source, respectively. Of course, the first nozzle 110 and the second nozzle 120 can also be connected to the passivating agent source and the oxidant source, respectively. This is simply a matter of controlling the flow rates of the two reactants to ensure they are matched. This does not affect the specific structure of the spray system.

[0062] Throughout the operation, the suction pipe 14 is connected to an external vacuum pump to keep the gas in the reaction chamber 10 being pumped, so as to guide the airflow and maintain an extremely low pressure in the chamber, tens of Pascals.

[0063] In summary, the working method of the reactor used for passivation coating of battery cell cross-sections according to the present invention is as follows:

[0064] a. Place the substrate cassette 20 containing the battery cells 22 onto the carrier, with the cut surface 23 facing the nozzle;

[0065] b. The carrier drives the slide box 20 to translate;

[0066] c. The nozzle sprays an oxidizing gas jet and a passivating gas jet onto the cut surface 23;

[0067] d. The thermal radiation device heats the cut surface 23 to the reaction temperature;

[0068] Steps b, c, and d occur simultaneously throughout the entire reaction process.

[0069] Furthermore, more preferably, the translation is a horizontal reciprocating motion to reduce the length of the reaction chamber 10.

[0070] In another embodiment, the reactor is further provided with the suction pipe 14, and the operating method further includes step e. The suction pipe 14 suctions to maintain a low pressure within the reaction chamber 10.

[0071] This invention also discloses an apparatus for passivation coating of battery cell cross-sections, comprising any of the reactors described above, a gas path for supplying reactive gas to the nozzle, and a power device for driving the carrier. In actual production, after placing the battery cell 22 and the cell carrier 20 on the carrier within the reaction chamber, the apparatus can operate simply by connecting it to an energy source, such as a power source to drive a motor, and connecting it to a reactive gas source to introduce reactive gas into the reaction chamber.

[0072] The present invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. A reactor for passivation coating of battery cell cross-sections, characterized in that, include: The reaction chamber is used for the coating reaction to take place therein. At least two sets of nozzles are arranged near the inner wall surface of the chamber. A carrier is arranged inside the chamber to drive the substrate holding the battery cells to translate and pass through the nozzles. The translation is a horizontal reciprocating uniform motion. The substrate carrier has an opening slot on the side facing the nozzle. The battery cells are placed into the substrate carrier through this opening slot, with each cell placed close to the others. The outermost cell is in contact with the inner wall of the opening slot, and the cut surface of the battery cell to be coated faces the nozzle. The nozzle includes a first nozzle and a second nozzle, which are respectively used to spray an oxidant gas jet and a passivator gas jet onto the cross-section of the battery cell to be coated in the reaction chamber. A thermal radiation device continuously radiates heat toward the cut surface, heating the cut surface to the reaction temperature; A gas nozzle, disposed on the wafer cassette for injecting gas into the wafer cassette, is connected to an external gas source for continuously injecting a chemically inert gas that will not chemically react with the reacting gases into the wafer cassette. This is to drive away any small amount of oxidizing and / or passivating gases that may enter the wafer cassette from the gaps formed by the grid lines at different positions. The gas flow direction of the gas injected into the wafer cassette from the gas nozzle is along the transverse direction of the solar cell, parallel to the length direction of the cross-section, and as perpendicular as possible to the gas flow direction of the reacting gases injected from each nozzle. The suction tube is connected to an external vacuum pump to evacuate the gas in the reaction chamber in order to maintain a near-vacuum low pressure in the reaction chamber. The cut surface receives passivating agent jets and oxidizing agent jets from different nozzles during movement, and is heated to the reaction temperature by a thermal radiation device, where an atomic layer deposition reaction occurs to generate a passivation layer coating.

2. The reactor according to claim 1, characterized in that, It also includes a synchronization mechanism for driving the thermal radiation device to maintain radiating heat toward the cut surface.

3. The reactor according to claim 1, characterized in that, The nozzle includes at least one row of first nozzles and at least one row of second nozzles arranged alternately with respect to the length direction of the cut surface; the spray direction of the nozzle is perpendicular to the translation direction.

4. The reactor according to claim 3, characterized in that, It also includes a first branch pipe and a second branch pipe arranged in parallel and staggered manner, with the first nozzle distributed on the first branch pipe along the length direction of the first branch pipe and the second nozzle distributed on the second branch pipe along the length direction of the second branch pipe.

5. The reactor according to any one of claims 1 to 4, characterized in that, The carrier is a row of horizontally placed parallel rollers, and the slide box is placed horizontally on the rollers. The gap between two adjacent rollers is less than half the length of the slide box.

6. The reactor according to claim 5, characterized in that, It also includes a tray placed on the roller and driven to translate by the roller; the slide box is placed on the tray.

7. The reactor according to any one of claims 1 to 4, characterized in that, The carrier is a horizontally placed conveyor belt, the slide box is placed on the conveyor belt or suspended below the conveyor belt, and the nozzle is disposed on the inner wall of the left and right sides of the reaction chamber.

8. The method of operating the reactor according to any one of claims 1 to 7, characterized in that, include: a) Place the wafer cassette with the battery cells on the carrier, with the cut surface facing the nozzle; b) Cause the carrier to drive the slide box to translate; c) The nozzle sprays an oxidizing gas jet and a passivating gas jet onto the cut surface; d) Heat the cut surface to the reaction temperature using the thermal radiation device; Steps b, c, and d occur simultaneously throughout the entire reaction process.

9. An apparatus for passivation coating of battery cell cross-sections, characterized in that, It includes a reactor as described in any one of claims 1 to 7, and a gas path for supplying reactive gas to the nozzle, and also includes a power device for driving the carrier.

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