Half-wafer edge passivation preparation method for BC battery
By using a flipping robotic arm and inert gas purging, the problem of film scratches caused by structural contact during the stacking of BC solar cells was solved, achieving efficient passivation treatment of BC cells and improving conversion efficiency and module power.
Patent Information
- Application Number
- CN202511083572.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-04
- Publication Date
- 2025-11-14
AI Technical Summary
In the prior art, the half-cell edge passivation process of BC cells cannot be applied to BC cells because the back grid lines scratch the front film layer due to the contact between the front and back sides of adjacent cells during stacking.
A flipping robot is used to stack homogeneous surfaces. Dust particles are removed by blowing with inert gas to prevent contact between the cells. An aluminum oxide film is deposited on the cross-section of the BC cell using atomic layer deposition technology, followed by annealing.
This effectively avoids film scratches caused by structural contact during the passivation process of BC solar cells at the half-cell edge, thereby improving photovoltaic conversion efficiency and module power.
Smart Images
Figure CN120957518A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a method for preparing half-cell edge passivation for use in BC batteries. Background Technology
[0002] With the development of crystalline silicon solar cell technology, BC (back contact) cell technology has emerged. Its core feature is that the emitter, surface field and metal electrode are all integrated on the back of the cell and distributed in an interdigitated manner, so that the front surface of the cell is completely free of grid lines. This structural design minimizes the loss of incident light, significantly improves the short-circuit current and conversion efficiency of the cell, simplifies the module packaging process and enhances the resistance to microcracks, and has a more aesthetically pleasing appearance.
[0003] In related technologies, half-cell edge passivation technology has been widely used in the production of mainstream cells such as TOPCon to improve module power and cell efficiency. This process typically involves cutting the cells in half after screen printing and laser-assisted sintering (LECO), and then depositing a passivation film such as alumina on the cut surface to reduce edge recombination losses, thereby significantly improving module power and cell conversion efficiency. The conventional operation is to stack the halved cells for passivation film deposition.
[0004] However, the edge passivation treatment method described above for half-cell batteries has significant problems when applied to BC batteries: due to the unique structure of BC batteries—no grid lines on the front and cross-finger-shaped metal grid lines on the back—the front and back sides of adjacent cells inevitably come into contact with each other during the stacking process required for passivation treatment. This contact easily causes the back grid lines to scratch the front film layer, resulting in a reduction in the passivation effect of the front film layer, which greatly affects the improvement of the conversion efficiency of BC batteries. Therefore, the half-cell edge passivation process cannot be applied to BC batteries for the time being. Currently, half-cell batteries are used directly for production, but the higher fragmentation rate and higher cost will affect the large-scale production of BC batteries. Summary of the Invention
[0005] Therefore, it is necessary to provide a half-cell edge passivation preparation method for BC cells to address the above problems, thereby solving the problem of back grid lines scratching the front film layer due to mutual contact of cells during the half-cell edge passivation process of BC cells. This allows the half-cell edge passivation process to be applied to the production of BC cells, thereby improving the photovoltaic conversion efficiency of BC cells.
[0006] A method for preparing half-cell edge passivation for BC batteries includes the following steps:
[0007] Step 1: Cut the laser-assisted sintered BC battery cell in half to obtain a half BC battery cell, and place the half BC battery cell face up in the carrier of the first battery transport line and the second battery transport line.
[0008] Step 2: The half of the BC battery cell on the first battery transport line is rotated and flipped by the flipping robot so that its reverse side faces up.
[0009] Step 3: The first handling robot grabs the half of the BC battery cell with the reverse side facing up, and at the same time, the second handling robot grabs the half of the BC battery cell with the front side facing up on the second battery transport line.
[0010] Step 4: Use inert gas to simultaneously blow the surface of the half-cell BC battery on both robotic arms;
[0011] Step 5: Stack the half-cells of BC cells held by the two robotic arms in the stacking station, so that the adjacent half-cells of BC cells are in face-to-face contact or back-to-back contact in the vertical direction, and the cut surface of the half-cells of BC cells is exposed at the deposition opening of the carrier.
[0012] Step 6: The stacked solar cells are transported to a chemical vapor deposition chamber, where an aluminum oxide film is deposited on the cross-section of the half-cell BC cell using atomic layer deposition under a vacuum of ≤10mTorr.
[0013] Step 7: Anneal the deposited alumina film.
[0014] As a further improvement to the above technical solution:
[0015] In one embodiment, the stacking process in step five specifically includes:
[0016] The first handling robot first places the reverse-side-up half of the BC battery cell into the stacking station;
[0017] The second handling robot places the front-facing half of the BC battery cell on top of the back-facing half of the BC battery cell, creating a back-to-back contact state.
[0018] Repeat the above steps to ensure that the subsequently stacked solar cells are always in contact with each other, either face to face or back to back, in the vertical direction.
[0019] In one embodiment, the atomic layer deposition process in step six includes repeatedly performing the following steps:
[0020] a. Introduce trimethylaluminum;
[0021] b. One purging step;
[0022] c. Introduce steam;
[0023] d. Secondary purging.
[0024] In one embodiment, trimethylaluminum is introduced in step a for 2-6 seconds;
[0025] In step b, nitrogen gas at a flow rate of 10,000-20,000 sccm is introduced for a purging process for 5-10 seconds.
[0026] In step c, steam is introduced for 3-6 seconds;
[0027] In step d, nitrogen gas at a flow rate of 10,000-20,000 sccm is introduced for a secondary purging for 6-10 seconds.
[0028] In one embodiment, in step a, high-purity nitrogen carrying trimethylaluminum is introduced at a flow rate of 2000-5000 sccm.
[0029] In one embodiment, in step c, high-purity nitrogen carrying water vapor is introduced at a flow rate of 1500-3000 sccm.
[0030] In one embodiment, the chamber temperature of the chemical vapor deposition chamber in step six is controlled at 100-200°C.
[0031] In one embodiment, the chamber temperature is 150°C.
[0032] In one embodiment, the inert gas purging time in step four is 15-60 seconds, and the purging gas is nitrogen.
[0033] In one embodiment, the annealing process in step seven is as follows:
[0034] The alumina film was irradiated with an infrared lamp and annealed at 280-360℃ for 20-40 minutes. After annealing, nitrogen gas was introduced into the deposition chamber to atmospheric pressure.
[0035] The above-mentioned half-cell edge passivation preparation method for BC cells achieves homogeneous surface stacking through a flipping robot. When the back of the cell faces the back, the grid line surface contacts the grid line surface; when the front of the cell faces the front, the textured surface contacts the textured surface. This avoids scratches on the front film layer caused by the contact between the front and back of the cell during the half-cell edge passivation process, which is due to structural differences. This improves the photovoltaic conversion efficiency of BC cells.
[0036] This application also has the following advantages:
[0037] Dust particles generated during cutting remain on the cut surface or battery surface, becoming "abrasive" and exacerbating scratches when stacked. This application uses inert gas to simultaneously spray nitrogen gas onto the battery cells on the first and second robotic arms to remove dust and particulate matter from the surface of half-cell BC battery cells, further avoiding scratches on the front film layer caused by contact between the half-cells. This allows the BC battery cells to achieve improved battery conversion efficiency and module power through the half-cell edge passivation process. Attached Figure Description
[0038] Figure 1 This is a schematic diagram of the transport flow of the half-cell BC battery cell of this application.
[0039] Figure 2 This is a schematic diagram of the structure of a half-cell BC solar cell according to this application.
[0040] Figure 3 This is a schematic diagram showing the stacking state of half-cell BC solar cells at the stacking station in this application.
[0041] Among them: 100, front of half BC battery; 200, back of half BC battery; 300, back grid lines; 400, cross-section of half BC battery; 500, flipping robot; 600, handling component; 700, stacking station; 800, first battery transport line; 900, second battery transport line;
[0042] 610. First handling robot; 620. Second handling robot. Detailed Implementation
[0043] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0044] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to 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.
[0045] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0046] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0047] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0048] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If 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. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0049] See Figures 1-3 The diagram shows a schematic of a method for preparing half-cell edge passivation for BC batteries according to an embodiment of this application.
[0050] This application provides a method for passivating the edge of a half-cell BC battery. Through rotation, stacking and cleaning processes, the method avoids the problem of scratches on the front film layer caused by the contact between the back grid line 300 and the front 100 of the BC battery due to structural differences, and at the same time achieves efficient passivation of the half-cell BC battery cut surface 400.
[0051] In some embodiments, the complete BC battery cell after laser-assisted sintering is cut into half pieces and transported to carriers of the first battery transport line 800 and the second battery transport line 900, respectively. A flipping robot 500 rotates and flips the half BC battery cell located on the first battery transport line 800 so that the reverse side 200 of the half BC battery cell on the first battery transport line 800 faces upwards. The first handling robot 610 of the handling assembly 600 picks up the reverse side 200 of the half BC battery cell from the first battery transport line 800. The half-cell BC battery cell with the front 100 facing upwards is picked up from the second battery transport line 900 by the second transport robot 620 of the transport assembly 600. The half-cell BC battery cell on the first transport robot 610 and the second transport robot 620 is simultaneously purged with inert gas. Then, the homogeneous surfaces of the half-cell BC battery cells on the first transport robot 610 and the second transport robot 620 are stacked at the stacking station 700. Finally, the cells are sent to the chemical vapor deposition chamber for edge passivation.
[0052] Furthermore, the following processes are included:
[0053] Step 1, placing half a battery:
[0054] The cut half-pieces of BC battery are placed in the carriers of the first battery transport line 800 and the second battery transport line 900 with the front side 100 of the half-piece BC battery facing upwards; wherein the front side 100 of the half-piece BC battery is a textured surface without grid lines, while the back side 200 of the half-piece BC battery has back grid lines 300.
[0055] Step 2, Flipping operation:
[0056] The flipping robot 500 grabs half a battery cell on the first battery transport line 800 and rotates it 180° so that the reverse side 200 of the half BC battery cell faces upward.
[0057] Step 3, the robotic arm simultaneously grasps:
[0058] The first handling robot 610 of the handling assembly 600 picks up the BC half battery piece with the reverse side 200 facing up (from the first transport line 800); the second handling robot 620 of the handling assembly 600 simultaneously picks up the BC half battery piece with the front side 100 facing up on the second battery transport line 900.
[0059] Step 4, inert gas purging:
[0060] Nitrogen gas is used to purge the surface of the battery cells on the first handling robot 610 and the second handling robot 620 simultaneously for 15–60 seconds. The purging gas is high-purity nitrogen with a flow rate of 10,000–20,000 sccm. This removes residual dust particles from the cutting process and prevents scratches on the front film layer caused by particles during stacking.
[0061] Step 5, stack homogeneous surfaces:
[0062] Perform the following operations within stacking station 700:
[0063] The first handling robot 610 places the half-cell BC battery with the reverse side 200 facing up into the stacking station 700;
[0064] The second handling robot 620 stacks the half-cell BC battery with the front 100 facing up on top of it, so that the two half-cell BC batteries form a reverse-to-reverse contact form in the vertical direction (i.e., the reverse sides 200 of the two half-cell BC batteries are opposite each other); and repeats the above action, so that the battery cells stacked later always maintain a homogeneous contact state of "front-to-front" or "reverse-to-reverse".
[0065] Meanwhile, the carrier is equipped with a deposition opening to ensure that the cross-section of the half-cell BC cell of all half cells is fully exposed, providing a passage for the deposition process;
[0066] Step 6, Atomic Layer Deposition
[0067] The stacked solar cells are fed into a chemical vapor deposition chamber, with the chamber temperature controlled at 100–200℃ (preferably 150℃) and a vacuum degree ≤10mTorr; an aluminum oxide film is deposited on the cross-section (400) using an ALD process, with the specific cycle as follows:
[0068] Trimethylaluminum (TMA) is introduced, with high-purity nitrogen gas at 2,000–5,000 sccm carrying the TMA, for 2–6 seconds;
[0069] One purging cycle involves introducing 10,000–20,000 sccm of nitrogen gas for 5–10 seconds.
[0070] Water vapor is introduced, carried by high-purity nitrogen gas at 1,500–3,000 sccm, for 3–6 seconds;
[0071] Secondary purging: Purge with 10,000–20,000 sccm of nitrogen for 6–10 seconds.
[0072] Repeat the above process, adjusting as needed for film thickness.
[0073] Step 7, Annealing:
[0074] The alumina film was locally irradiated with an infrared lamp and annealed at 280–360℃ for 20–40 minutes. After annealing, nitrogen gas was introduced into the deposition chamber to atmospheric pressure to complete the passivation of the half-wafer edge.
[0075] Example 1:
[0076] The half-cell edge passivation of the BC battery is completed through the following process:
[0077] Step 1, placing half a battery:
[0078] The cut half-pieces of BC battery are placed in the carriers of the first battery transport line 800 and the second battery transport line 900 with the front side 100 of the half-piece BC battery facing upwards; wherein the front side 100 of the half-piece BC battery is a textured surface without grid lines, while the back side 200 of the half-piece BC battery has back grid lines 300.
[0079] Step 2, Flipping operation:
[0080] The flipping robot 500 grabs half a battery cell on the first battery transport line 800 and rotates it 180° so that the reverse side 200 of the half BC battery cell faces upward.
[0081] Step 3, the robotic arm simultaneously grasps:
[0082] The first handling robot 610 of the handling assembly 600 picks up the BC half battery piece with the reverse side 200 facing up (from the first transport line 800); the second handling robot 620 of the handling assembly 600 simultaneously picks up the BC half battery piece with the front side 100 facing up on the second battery transport line 900.
[0083] Step 4, inert gas purging:
[0084] Nitrogen gas is used to purge the surface of the battery cells on the first handling robot 610 and the second handling robot 620 simultaneously. The purging gas is high-purity nitrogen, the flow rate is 10000 sccm, and the purging time is 60s.
[0085] Step 5, stack homogeneous surfaces:
[0086] Perform the following operations within stacking station 700:
[0087] The first handling robot 610 places the half-cell BC battery with the reverse side 200 facing up into the stacking station 700;
[0088] The second handling robot 620 stacks the half-cell BC battery with the front 100 facing up on top of it, so that the two half-cell BC batteries form a reverse-to-reverse contact form in the vertical direction (i.e., the reverse sides 200 of the two half-cell BC batteries are opposite each other); and repeats the above action, so that the battery cells stacked later always maintain a homogeneous contact state of "front-to-front" or "reverse-to-reverse".
[0089] Meanwhile, the carrier is equipped with a deposition opening to ensure that the half-cell BC cell cross-section 400 of all half cells is fully exposed, providing a passage for the deposition process;
[0090] Step 6, Atomic Layer Deposition
[0091] The stacked solar cells are fed into a chemical vapor deposition chamber, where the temperature is controlled at 150°C and the vacuum level is ≤10 mTorr. An aluminum oxide film is deposited on the 400mm cross-section of the half-cell BC using an ALD process, with the specific cycle as follows:
[0092] Trimethylaluminum (TMA) is introduced: the flow rate of high-purity nitrogen carrying TMA is 5000 sccm, and the introduction time is 5s;
[0093] First purging: High-purity nitrogen is introduced into the chemical vapor deposition chamber for purging to remove unreacted gases or byproducts of the reaction. The flow rate of the purging nitrogen is 15000 sccm and the purging time is 5s.
[0094] Water vapor is introduced: oxygen source water vapor is carried into the chemical vapor deposition chamber by high-purity carrier gas (N2), so that the water vapor reacts with TMA adsorbed on the cross surface of the half cell to form an aluminum oxide layer. The flow rate of high-purity nitrogen carrying oxygen source water vapor is 3000 sccm and the source time is 5s.
[0095] Secondary purging: High-purity nitrogen gas is introduced into the chemical vapor deposition chamber for purging to remove unreacted gases or byproducts of the reaction. The flow rate of the purging nitrogen gas is 15000 sccm and the purging time is 6s.
[0096] This process is repeated 100 times to deposit an aluminum oxide film with a thickness of 12 nm on the cross-sectional surface of a half-cell BC solar cell.
[0097] Step 7, Annealing:
[0098] Infrared lamps were used to heat and irradiate the aluminum oxide film on the cut surface of the half-cell BC battery cell for annealing treatment. The annealing temperature was 330℃ and the annealing time was 30min. After the annealing treatment, the chemical vapor deposition chamber was filled with nitrogen to atmospheric pressure, and the carrier exited the chamber to complete the edge passivation of the half-cell.
[0099] Example 2:
[0100] In this embodiment, the difference from Embodiment 1 is that the purging time of the inert gas in step four of Embodiment 1 is changed to 30 seconds, while the rest of the process remains the same as in Embodiment 1.
[0101] Example 3:
[0102] In this embodiment, the difference from Embodiment 1 is that the purging time of the inert gas in step four of Embodiment 1 is changed to 15 seconds, while the rest of the process remains the same as in Embodiment 1.
[0103] Comparative Example 1:
[0104] Half-cell BC solar cells without any treatment were used.
[0105] Comparative Example 2:
[0106] In Comparative Example 2, the difference from Example 1 is that the flipping operation in step 2 of Example 1 is cancelled, and the first handling robot 610 and the second handling robot 620 of the handling component 600 are used directly to stack the half BC battery cell into the stacking station 700. The rest of the process is the same as in Example 1.
[0107] Comparative Example 3:
[0108] In Comparative Example 3, the difference from Example 1 is that the blowing step of the half-cell battery picked up by the first handling robot 610 and the second handling robot 620 in step 4 is cancelled, that is, the blowing is not performed before placing it into the stacking station 700, and the rest of the process is consistent with Example 1.
[0109] The half-cell BC solar cells processed in Examples 1-3 and Comparative Examples 1-3 were packaged into modules, and the performance of the packaged modules was tested. The test results are shown in Table 1 below.
[0110] Table 1
[0111]
[0112]
[0113] In Table 1, Voc is the open-circuit voltage of the solar cell, Isc is the short-circuit current of the solar cell, FF is the fill factor of the solar cell, and Pmax is the power generation of the half-cell BC solar cell module after encapsulation.
[0114] As can be seen from Table 1 above, based on the comparison between Embodiment 1 and Comparative Example 1 or Embodiment 1 and Comparative Example 2 in this application, this application adds a flipping robot 500 to rotate half of the battery cells located on the first battery transport line 610 to the reverse side, so that when stacked, adjacent battery cells only form a homogeneous surface contact state of front-to-front or back-to-back, which can avoid scratches on the front film layer caused by the different structures of the half battery cells contacting each other, and can realize the improvement of module power after the edge passivation of BC battery half cells.
[0115] Based on the comparison between Examples 1 to 3, and the comparison between Example 1 and Comparative Example 3, it can be seen that after the transport module 600 picks up half of the solar cell and before cross-stacking, the present application adds an inert gas purging process. As the purging time increases, the module power gradually increases. This indicates that purging the dust and particulate matter on the surface of the half BC solar cell can further avoid scratches on the front film layer caused by the contact between the half solar cells, thereby improving the module power.
[0116] In summary, this application adds a flipping robot 500 to the BC cell half-cell edge passivation process during the stacking process. The robot grips half of the cells on the first battery transport line 610 and rotates them 180° to the reverse side. This ensures that the half-cells of the BC cells are in a "front-to-front" or "back-to-back" contact state at the stacking station 700. This avoids the traditional situation where the front and back sides of the half-cells come into contact during the stacking process, which can cause scratches on the front film layer of the half-cells due to their different structures. At the same time, this application uses inert gas to blow on the surface of the half-cells before the stacking process, which can clean the dust and particles on the surface of the half-cells of the BC cells. This further avoids scratches on the front film layer caused by the contact between the half-cells, allowing the BC cells to achieve improved battery conversion efficiency and module power through the half-cell edge passivation process.
[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0118] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method for preparing half-cell edge passivation for BC batteries, characterized in that, The process includes the following steps: Step 1: Cut the laser-assisted sintered BC solar cell in half to obtain a half BC solar cell, and place the half BC solar cell face up in the carrier of the first and second battery transport lines. Step 2: The half of the BC battery cell on the first battery transport line is rotated and flipped by the flipping robot so that its reverse side faces up. Step 3: The first handling robot grabs the half of the BC battery cell with the reverse side facing up, and at the same time, the second handling robot grabs the half of the BC battery cell with the front side facing up on the second battery transport line. Step 4: Use inert gas to simultaneously blow the surface of the half-cell BC battery on both robotic arms; Step 5: Stack the half-cells of BC cells held by the two robotic arms in the stacking station, so that the adjacent half-cells of BC cells are in face-to-face contact or back-to-back contact in the vertical direction, and the cut surface of the half-cells of BC cells is exposed at the deposition opening of the carrier. Step 6: The stacked solar cells are transported to a chemical vapor deposition chamber, where an aluminum oxide film is deposited on the cross-section of the half-cell BC cell using atomic layer deposition under a vacuum of ≤10mTorr. Step 7: Anneal the deposited alumina film.
2. The method for preparing half-cell edge passivation for BC batteries according to claim 1, characterized in that, The stacking process in step five specifically includes: The first handling robot first places the reverse-side-up half of the BC battery cell into the stacking station; The second handling robot places the front-facing half of the BC battery cell on top of the back-facing half of the BC battery cell, creating a back-to-back contact state. Repeat the above steps to ensure that the subsequently stacked solar cells are always in contact with each other, either face to face or back to back, in the vertical direction.
3. The method for preparing half-cell edge passivation for BC batteries according to claim 1, characterized in that, Step six, the atomic layer deposition process, involves cyclically performing the following steps: a. Introduce trimethylaluminum; b. One purging step; c. Introduce steam; d. Secondary purging.
4. The method for preparing half-cell edge passivation for BC batteries according to claim 3, characterized in that, The duration of introducing trimethylaluminum in step a is 2-6 seconds; In step b, nitrogen gas at a flow rate of 10,000-20,000 sccm is introduced for a purging process for 5-10 seconds. The duration of introducing water vapor in step c is 3-6 seconds; In step d, nitrogen gas at a flow rate of 10,000-20,000 sccm is introduced for a secondary purging for 6-10 seconds.
5. The method for preparing half-cell edge passivation for BC batteries according to claim 4, characterized in that, In step a, high-purity nitrogen carrying trimethylaluminum is introduced at a flow rate of 2000-5000 sccm.
6. The method for preparing half-cell edge passivation for BC batteries according to claim 4, characterized in that, In step c, high-purity nitrogen carrying water vapor is introduced at a flow rate of 1500-3000 sccm.
7. The method for preparing half-cell edge passivation for BC batteries according to claim 1, characterized in that, The chamber temperature of the chemical vapor deposition chamber in step six is controlled at 100-200℃.
8. The method for preparing half-cell edge passivation for BC batteries according to claim 7, characterized in that, The temperature of the chamber is 150°C.
9. The method for preparing half-cell edge passivation for BC batteries according to claim 1, characterized in that, In step four, the inert gas purging time is 15-60 seconds, and the purging gas is nitrogen.
10. The method for preparing half-cell edge passivation for BC batteries according to claim 1, characterized in that, The annealing process in step seven is as follows: The alumina film was irradiated with an infrared lamp and annealed at 280-360℃ for 20-40 minutes. After annealing, nitrogen gas was introduced into the deposition chamber to atmospheric pressure.