Battery piece grid line preparation method and battery piece

Abstract

The invention relates to a cell grid line preparation method, which combines the advantages of a photoetching technology and a hot stamping technology and realizes high-precision and high-efficiency preparation of grid lines. A photoresist layer and an imprinting glue layer are sequentially formed on a battery piece, and a transparent mold with a light shielding layer and a bulge is used for hot pressing treatment, so that a first groove can be pressed in the imprinting glue layer, and a non-exposure area is shielded by using the light shielding layer. And during hot pressing, exposing a region corresponding to the first groove in the photoresist layer, and then removing the exposed photoresist layer region to form a second groove. The imprint glue layer and the photoresist layer are immiscible, and polylactic acid is used as an imprint glue layer material, so that the preparation precision and stability of the grid line are improved. The cell grid line prepared by the method has fine width and height control, the photoelectric conversion efficiency and stability of the solar cell are improved, the production cost is reduced, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method for preparing a grid line of a solar cell and a solar cell. Background Art

[0002] In today's global energy structure, burning coal as the main way to generate electricity cannot be ignored. However, with the accelerated pace of industrialization and the sharp increase in global energy consumption, the reserves of non-renewable resources such as coal are becoming increasingly depleted. What is more serious is that the mining and utilization of these traditional energy sources have caused serious negative impacts on the natural environment, such as air pollution, greenhouse gas emissions, and water resource damage. In order to meet this challenge, reduce dependence on fossil fuels, and promote the sustainable development of the global energy system, governments and international organizations have turned their attention to the development and utilization of renewable energy. Among them, solar energy, as a clean and unlimited energy source, is regarded as one of the most promising alternatives.

[0003] The invention and continuous optimization of solar cells have made it possible to achieve efficient use of solar energy. In the production process of solar cells, photovoltaic silver paste is a key material, and its quality and preparation process have a crucial impact on the performance of the cell. Photovoltaic silver paste is mainly used to form electrodes on solar silicon wafers. By optimizing its scraping process, the conductivity and photoelectric conversion efficiency of solar cells can be significantly improved, thereby reducing costs and increasing energy output.

[0004] At present, the industry mainly uses printing technology to plate a layer of electrode on photovoltaic cells. Among them, screen printing technology is widely used in large-scale industrial production because of its relatively low cost and relatively mature process. However, there are still a series of problems that need to be solved in the process of screen printing technology to plate electrodes on silicon wafers. First, insufficient printing accuracy is a significant problem. Due to the instability of printing parameters and various changes in the printing process, it is difficult to keep the width and thickness of the printed silver paste consistent. This unevenness will directly affect the resistance of the battery cell, and then have an adverse effect on the overall performance of the battery. In addition, screen printing technology is also difficult to achieve high-resolution printing of fine patterns below 10μm, which limits the application of solar cells in more high-end fields. Secondly, material waste is also a major challenge facing screen printing technology. During the printing process, due to process limitations and improper operation, a large amount of waste is often generated, resulting in waste of silver paste, thereby increasing production costs, which is not only not conducive to the economic benefits of the enterprise, but also violates the principle of sustainable development.

[0005] In response to the above problems, although some alternative solutions such as RIE (reactive ion etching) process have been proposed, the RIE process is difficult to industrialize, the cost is high, and it still faces many technical bottlenecks in practical applications, so it has not been widely promoted. Therefore, developing a new method for preparing grid lines of battery cells and battery cells to overcome the shortcomings of existing technologies, improve printing accuracy, reduce material waste, and improve production efficiency has become an important issue that needs to be solved in the current solar cell field. Summary of the invention

[0006] The purpose of the present application is to provide a method for preparing a grid line of a cell sheet, which can accurately control the size of the grid line, simplify the preparation process, and realize a high-resolution photovoltaic silver paste electrode imprinting method. The method for preparing a grid line of a cell sheet of the present application includes: forming a photoresist layer on the cell; forming an imprinting resist layer on the photoresist layer; Using a transparent mold with a light shielding layer and a protrusion for hot pressing, hot pressing a first groove in the embossed adhesive layer, wherein the light shielding layer shields light outside a region corresponding to the first groove, and exposing the region corresponding to the first groove in the photoresist layer during hot pressing; Removing the exposed area in the photoresist layer to form a second groove in the imprinting glue layer and the photoresist layer; Filling the second groove with conductive paste, and drying the conductive paste; removing the remaining photoresist layer and the embossing adhesive layer; Converting the conductive paste into a cell grid line; Wherein, the embossing glue layer and the photoresist layer are immiscible.

[0007] In one embodiment, the step of filling the second groove with a conductive paste further comprises making the conductive paste flush with the upper surface of the embossed adhesive layer by scraping.

[0008] In one embodiment, the material of the embossed adhesive layer is polylactic acid.

[0009] In one embodiment, the photoresist layer and the imprinting adhesive layer are dissolved and removed simultaneously using the same solvent.

[0010] In one embodiment, the solvent is acetone.

[0011] In one of the embodiments, the width of the second groove is in the range of 2-100 μm.

[0012] In one embodiment, the thickness of the photoresist layer is in the range of 1-5 μm, and the thickness of the embossing layer is in the range of 5-50 μm.

[0013] In one embodiment, the direction of the light is the extension direction of the protrusion.

[0014] In addition, the present application also provides a battery cell, including grid lines formed on a surface, wherein the grid lines are obtained by the above-mentioned battery cell grid line preparation method.

[0015] In one embodiment, the width of the gate line is in the range of 2-100 μm.

[0016] Compared with the prior art, the present application has the following beneficial effects: the method for preparing the grid line of a cell provided by the present application and the cell obtained therefrom can realize high-precision grid line production compared with the prior art, by combining hot stamping and UV photolithography technology, using a transparent mold with a light shielding layer and a protrusion to accurately heat-press the first groove in the stamping glue layer, and simultaneously exposing the photoresist layer, thereby realizing high-precision production of the grid line. The width of the second groove can be controlled within the range of 2-100μm, and the width and height of the grid line can also be precisely controlled, meeting the requirements of solar cells for grid line refinement, and effectively improving the photoelectric conversion efficiency and performance stability of the battery.

[0017] Reduce material waste and reduce costs. In the step of filling the second groove with the conductive paste, the conductive paste is leveled with the upper surface of the imprinted adhesive layer by scraping, which not only ensures the uniform distribution of the silver paste, but also almost eliminates the generation of silver paste waste, significantly reducing production costs. In addition, polylactic acid (PLA) is used as the imprinted adhesive layer material, and its good film-forming properties and non-miscibility with the photoresist layer further ensure that the silver paste can maintain a good shape during the curing process, avoiding the degradation of battery performance due to shape differences. There is no need to adopt a complex RIE process, and the operation can be directly performed on the silicon wafer. The preparation of the gate line can be achieved through simple hot stamping and photolithography steps. The process flow is greatly simplified. The method of the present application can meet the needs of large-scale production and significantly improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the production process in the embodiment of the present application.

[0019] Explanation of reference numerals: 100, battery cell; 200, photoresist layer; 300, embossed adhesive layer; 310, first groove; 320, second groove; 400, transparent mold; 500, battery cell grid line. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0021] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] Although traditional methods for preparing grid lines 500 of solar cells, such as screen printing technology, have been widely used in industry, they still have problems such as poor printing accuracy, material waste, and low production efficiency, which limit the further improvement of solar cell performance. In order to overcome these technical bottlenecks, researchers and engineers are constantly exploring new technologies for preparing grid lines 500 of solar cells, in order to achieve more efficient, more environmentally friendly, and more economical production of solar cells 100. This application proposes a method based on the combination of hot stamping and UV lithography, which combines hot stamping, UV lithography and advanced material technology to achieve high-precision, low-cost and environmentally friendly preparation of grid lines. Please refer to Figure 1As shown, a method for preparing a cell grid line 500 in a preferred embodiment of the present application is suitable for finely manufacturing grid lines. The method for preparing a cell grid line 500 comprises: forming a photoresist layer 200 on a cell 100, forming an embossed adhesive layer 300 on the photoresist layer 200, using a transparent mold 400 having a light shielding layer and protrusions for hot pressing, hot pressing a first groove 310 in the embossed adhesive layer 300, wherein the light shielding layer shields light outside the corresponding area of ​​the first groove 310, and hot pressing the photoresist layer 200 while hot pressing. The area corresponding to the first groove 310 in the glue layer 200 is exposed, the exposed area in the photoresist layer 200 is removed, and a second groove 320 is formed in the stamped glue layer 300 and the photoresist layer 200, and the second groove 320 is filled with a conductive paste, and the conductive paste is dried; the remaining photoresist layer 200 and the stamped glue layer 300 are removed; the conductive paste is converted into a battery cell grid line 500; wherein the stamped glue layer 300 and the photoresist layer 200 are not miscible.

[0024] First, a layer of photoresist 200 is evenly coated on the battery cell 100, and the photoresist layer 200 will serve as the basis for subsequent exposure and development. Next, a layer of embossed adhesive layer 300 is coated on the photoresist layer 200. The embossed adhesive layer 300 needs to have good hot pressing deformation ability, and ensure that the two do not dissolve in each other during subsequent processing. Subsequently, a transparent mold 400 with a light-shielding layer and a protrusion is used to perform hot pressing on the embossed adhesive layer 300. The protrusion of the mold will press out a first groove 310 in the embossed adhesive layer 300 during the hot pressing process, and the light-shielding layer effectively blocks the light outside the area corresponding to the first groove 310, preventing exposure of these areas. While hot pressing, a specific light source is used to accurately expose the area corresponding to the first groove 310 in the photoresist layer 200, so that the photoresist in this area undergoes a chemical reaction, preparing for subsequent removal. The material of the transparent mold 400 is PET or glass. Specifically, the convex portion can be formed by etching away the unnecessary area on the material, or the convex portion can be connected to a whole layer of material to form the transparent mold 400. After the exposure is completed, the exposed area in the photoresist layer 200 is removed by a development process, so that a second groove 320 is formed in the photoresist layer 200 and the embossed adhesive layer 300. The accuracy of this step is crucial to the final shape and size of the grid line. Next, the second groove 320 is filled with a conductive paste, and the paste is cured by a drying process. The selection of the conductive paste should meet good conductivity and good adhesion to the substrate of the battery cell 100. After the conductive paste is dried, the remaining photoresist layer 200 and the embossed adhesive layer 300 are removed to expose the cured conductive paste, i.e., the battery cell grid line 500. This step is usually achieved by chemical stripping or physical stripping, and the integrity and accuracy of the grid line must be ensured. Through further heat treatment or chemical treatment, the conductive paste is converted into a battery cell grid line 500 with stable conductive properties, which helps to improve the durability and reliability of the grid line.

[0025] By combining photolithography and hot stamping technology, the method of the present application can accurately control the shape, size and position of the grid line, realize high-precision grid line production, and thus improve the photoelectric conversion efficiency of the solar cell. Compared with the traditional method for preparing the grid line 500 of the cell, the present application reduces material waste and process complexity, and reduces production costs. The immiscibility of the embossed adhesive layer 300 and the photoresist layer 200 ensures the stability and independence of the two in the subsequent processing process, and provides a reliable guarantee for the production of high-precision grid lines. In summary, the method for preparing the grid line 500 of the cell of the present application shows significant technical advantages in terms of refined production, cost control, environmental protection and compatibility. Compared with only using hot stamping technology to form a groove, the present application uses a photoresist layer 200 as the bottom layer, which can avoid the residue of the embossed adhesive on the surface of the cell by dissolving the photoresist, and the surface of the cell where the grid line is formed is cleaner, and the embossing mold will not directly contact the surface of the cell, especially for the front side of the cell with a velvet structure and an anti-reflection layer, which can minimize the impact of impurities and contact. Compared with using only photoresist, the present application can significantly reduce the amount of photoresist used by using a lower-cost and more readily available imprinting resin, and imprinting and photolithography can be formed in one step without the need for secondary alignment. The method of the present application better balances the relationship between production accuracy and production cost, allowing the present application to achieve fine production of battery cell grid lines at a low cost, which has many advantages over traditional screen printing.

[0026] Specifically, the step of filling the second groove 320 with the conductive paste also includes making the conductive paste flush with the upper surface of the embossed adhesive layer 300 by scraping. In the step of filling the second groove 320 with the conductive paste, the method of the present application introduces a scraping process, which uses a precise scraper or similar flattening tool to evenly coat the conductive paste in the second groove 320 and ensures that the paste surface is flush with the upper surface of the embossed adhesive layer 300. During the scraping process, the conductive paste is accurately distributed to every corner of the second groove 320, avoiding waste and accumulation of the paste, and also ensuring the consistency and stability of the gate line in subsequent processing. In addition, the scraping process also helps to eliminate the tiny unevenness that may exist on the surface of the slurry, and further improves the flatness and smoothness of the grid line, which is crucial to improving the photoelectric conversion efficiency of solar cells. It not only improves the appearance quality of the grid line, but also reduces the increase in resistance caused by uneven distribution of the slurry, thereby improving the photoelectric conversion efficiency of solar cells. The high precision and controllability of the scraping process make the production of the grid line more stable and reliable, reduce the changes in the size and shape of the grid line caused by process fluctuations, and improve the consistency and reliability of solar cells. The flat grid line surface is conducive to subsequent processing steps such as cleaning, drying and curing, reduces the processing difficulties and defects caused by surface unevenness, and further improves the production efficiency and yield of solar cells. By introducing the scraping process, the method of the present application achieves higher precision and stability in the step of filling the second groove 320 with the conductive slurry. Specifically, the material of the embossed adhesive layer 300 is polylactic acid. Polylactic acid (PLA), also known as polylactide, is a polyester polymer obtained by polymerization with lactic acid as the main raw material. It has good degradability and good thermal stability. By scraping silver paste on the PLA film with grooves and the silicon wafer of PR photoresist, the silver paste can be well kept in its original shape during curing, so that this method hardly produces silver paste waste, reducing production costs. In addition, further, the material of the embossed adhesive layer 300 is selected from polylactic acid-glycolic acid copolymer (poly(lactic-co-glycolicacid) PLGA), which is randomly polymerized by two monomers-lactic acid and glycolic acid, and is a degradable functional polymer organic compound with good biocompatibility, non-toxicity, and good capsule and film-forming properties.

[0027] Specifically, the photoresist layer 200 and the embossed adhesive layer 300 are dissolved and removed simultaneously using the same solvent. A specific solvent that can effectively dissolve both the photoresist layer 200 and the embossed adhesive layer 300 is selected to achieve simultaneous removal of the two in the same processing step. This step is usually performed after the conductive paste is dried and converted into the cell grid line 500, aiming to remove all non-conductive parts and expose the complete grid line structure. Through the synchronous dissolution and removal technology, the two removal steps that originally needed to be performed step by step are combined into one, which greatly simplifies the process flow and improves production efficiency. The photoresist layer 200 and the embossed adhesive layer 300 are dissolved and removed simultaneously using the same solvent, avoiding waste and cross contamination between different solvents.

[0028] Specifically, the solvent is acetone. PLA can be removed by organic solvents such as acetone, and will not dissolve in weak alkali, ensuring that it can be retained when part of the photoresist PR glue is removed in the second step, and finally the PR glue and PLA can be removed together by organic solvents such as acetone. In order to solve this RIE problem, the scheme uses a combination of hot stamping and UV photolithography, taking advantage of the different solubilities of polylactic acid and PR glue. PLA and PR photoresist will not react with the organic solvent in the silver paste to produce adhesion, so that the silver paste can maintain its own shape well during the curing process, reducing the impact of the different shapes of the silver paste on the performance of solar cells. Moreover, the method has a simple process flow and high process precision, and is directly operated on the battery cell 100, which can achieve large-scale production.

[0029] Specifically, the width of the second groove 320 is in the range of 2-100μm. In the step of preparing the cell grid line 500, the present application precisely controls the width of the second groove 320 and sets it in the range of 2-100μm. The selection of this width range is based on in-depth research and comprehensive consideration of the photoelectric conversion efficiency, current collection capability and manufacturing cost of solar cells. In actual operation, the width of the second groove 320 can be precisely controlled by adjusting parameters such as the size of the raised portion of the imprinting mold, the imprinting pressure, the imprinting time, and the temperature. At the same time, it is also necessary to ensure that factors such as the thickness, uniformity, and interaction force between the photoresist layer 200 and the imprinting glue layer 300 are in the best state to ensure the accuracy and consistency of the width of the second groove 320. Specifically, the thickness of the photoresist layer 200 is in the range of 1-5 μm, and the thickness of the embossed adhesive layer 300 is in the range of 5-50 μm. In actual operation, the thickness of the photoresist layer 200 is precisely controlled by adjusting the parameters of the coating process (such as coating speed, coating amount, etc.). A thinner photoresist layer 200 can reduce the material consumption during exposure and development, while ensuring sufficient resolution and contrast to form a clear grid line pattern, while the thickness of the embossed adhesive layer 300 is controlled by adjusting the parameters such as the protrusion height, imprinting pressure and imprinting time of the imprinting mold. The thicker embossed adhesive layer 300 can provide sufficient deformation capacity to accommodate the shape of the mold protrusion and form a precise second groove 320 during the hot pressing process. By precisely controlling the thickness of the photoresist layer 200 and the embossed adhesive layer 300, the influence of process parameter fluctuations on grid line production can be reduced, and the stability and reliability of the process can be improved. The thickness of the embossed adhesive layer is preferably in the range of 8-20 μm. Within this range, the morphology of the embossed adhesive layer is easier to control, which can further achieve precise control of the size and morphology of the gate lines and greatly improve the process stability.

[0030] Specifically, the direction of the light is the extension direction of the protrusion. In actual operation, the light is incident on the photoresist layer 200 at the same angle as the extension direction of the protrusion, and is exposed through the pattern on the mask. Since the direction of the light is consistent with the extension direction of the protrusion, the pattern formed during the photolithography process will naturally match the shape of the protrusion on the imprint mold. Designing the direction of the light to be consistent with the extension direction of the protrusion can significantly improve the alignment accuracy and process efficiency of the preparation of the cell grid line 500.

[0031] In order to improve the efficiency and accuracy of material discharge, the mold is provided with an overflow channel, which is arranged on the side of the protrusion. During stamping, excess material can enter the overflow channel. Furthermore, it also includes an air flow channel connected to the overflow channel. Pressure is provided through the air flow channel, so that detection and a certain gas pressure can also be provided through the air flow channel. These air flow channels not only serve as auxiliary channels for material discharge, but also can help adjust and optimize the stamping process by providing controllable gas pressure.

[0032] In addition, the present application also provides a battery cell 100, including grid lines formed on the surface, wherein the grid lines are obtained by the aforementioned method for preparing the battery cell grid lines 500.

[0033] Specifically, the width of the gate line is within the range of 2-100 μm, and further, the width of the gate line is selected within the range of 2-10 μm. The preparation method of the present application can accurately realize the production of the gate line within this size range. In addition, the height of the gate line is within the range of 10-50 μm, and further, the height of the gate line is preferably within the range of 8-25 μm. Through the manufacturing method of the present application, the width and height of the gate line can be within a fine range, which can improve the efficiency and stability of the battery cell 100.

[0034] The technical solution of the present application is further explained below with a specific implementation method. The present application first scrapes a layer of 1-3μm PR photoresist on the battery cell, and then applies a layer of 9-10μm PLA film on it after the PR glue is cured, and then uses a transparent film with a light-shielding layer to hot-press the height and width required for scraping the silver paste. Since there is still 1-2μm PR glue bonded to the silicon wafer at this time, the silver paste cannot directly contact the silicon wafer, so the PR glue is irradiated with a UV lamp while hot pressing, and then the irradiated PR glue is cleaned with a developer until all the residual PR glue on the groove is removed and the silicon wafer is exposed to form a high-precision groove pattern. Pour the silver paste on the silicon wafer with the groove and scrape it flat, then put it into an oven to dry the silver paste. After the silver paste is dried, put the silicon wafer with the silver paste into an organic solvent (such as acetone) to dissolve the PLA and PR glue on the silicon wafer at the same time, and finally sinter the silver paste.

[0035] As can be seen from the foregoing, the present application proposes a new method for preparing grid lines of a cell, which combines the advantages of photolithography technology and hot stamping technology to achieve high-precision and high-efficiency preparation of grid lines. The method includes the following key steps: First, a photoresist layer with a thickness in the range of 1-5μm is evenly coated on the cell, and the photoresist layer serves as the basis for subsequent exposure and development. Next, a layer of embossed adhesive layer with a thickness in the range of 5-50μm is coated on the photoresist layer. The embossed adhesive layer is made of polylactic acid (PLA) and has good hot pressing deformation ability, while ensuring that it does not dissolve with the photoresist layer during subsequent processing. The embossed adhesive layer is hot-pressed using a transparent mold having a light-shielding layer and a protrusion. The protruding part of the mold will press out a first groove in the embossed adhesive layer during the hot pressing process, and the light-shielding layer effectively blocks the light outside the area corresponding to the first groove, preventing exposure of these areas. During the hot pressing, a specific light source is used to accurately expose the area corresponding to the first groove in the photoresist layer, so that the photoresist in this area undergoes a chemical reaction, preparing for the subsequent removal work. It is worth noting that the incident direction of the light is consistent with the extension direction of the protrusion, thereby improving the alignment accuracy and process efficiency.

[0036] After the conductive paste is dried, an organic solvent such as acetone is used to remove the remaining photoresist layer and the embossed adhesive layer, exposing the cured conductive paste, i.e., the cell grid line. Acetone, as a solvent, can effectively dissolve both the photoresist layer and the embossed adhesive layer at the same time, achieving the simultaneous removal of both in the same processing step, greatly simplifying the process flow and improving production efficiency. Through further heat treatment or chemical treatment, the conductive paste is converted into a cell grid line with stable conductive properties. The width of the grid line is controlled in the range of 2-100μm and the height is in the range of 10-50μm. Such fine dimensions help improve the photoelectric conversion efficiency and stability of solar cells.

[0037] In summary, the cell grid line preparation method of the present application shows significant technical advantages in terms of refined production, cost control, environmental protection and compatibility. The method can accurately control the shape, size and position of the grid line, realize high-precision grid line production, and thus improve the photoelectric conversion efficiency of the solar cell. At the same time, the method reduces material waste and process complexity, reduces production costs, and provides strong support for the large-scale production of solar cells. Through this method of the present application, very fine patterns (2-10μm wide) can be scraped on silicon wafers, and the thickness of the scraped silver paste can be accurately controlled, thereby ensuring that the performance of the solar cell will not be reduced due to uneven thickness of the silver paste. Moreover, the method of the present application hardly generates waste, which greatly saves the cost of the amount of silver paste.

[0038] The above is only a specific implementation of the present application, and any other improvements made based on the concept of the present application are deemed to be within the protection scope of the present application.

Claims

1. A method for preparing a cell grid line (500), characterized in that: include: forming a photoresist layer (200) on the battery cell (100); forming an embossed adhesive layer (300) on the photoresist layer (200); Using a transparent mold (400) having a light shielding layer and a protrusion for hot pressing, a first groove (310) is hot pressed in the embossed adhesive layer (300), the light shielding layer shielding light outside the area corresponding to the first groove (310), and exposing the area corresponding to the first groove (310) in the photoresist layer (200) during hot pressing; Removing the exposed area in the photoresist layer (200), and forming a second groove (320) in the imprinted adhesive layer (300) and the photoresist layer (200); Filling the second groove (320) with conductive paste, and drying the conductive paste; removing the remaining photoresist layer (200) and the embossing adhesive layer (300); Converting the conductive paste into a cell grid line (500); Wherein, the embossing glue layer (300) and the photoresist layer (200) are immiscible.

2. The method for preparing a cell grid line (500) according to claim 1, characterized in that: The step of filling the second groove (320) with conductive paste also includes making the conductive paste flush with the upper surface of the embossed adhesive layer (300) by scraping.

3. The method for preparing a cell grid line (500) according to claim 1, characterized in that: The material of the embossed adhesive layer (300) is polylactic acid.

4. The method for preparing a cell grid line (500) according to claim 3, characterized in that: The photoresist layer (200) and the embossing adhesive layer (300) are dissolved and removed simultaneously using the same solvent.

5. The method for preparing a cell grid line (500) according to claim 4, characterized in that: The solvent is acetone.

6. The method for preparing a cell grid line (500) according to claim 1, characterized in that: The width of the second groove (320) is in the range of 2-100 μm.

7. The method for preparing a cell grid line (500) according to claim 6, characterized in that: The thickness of the photoresist layer (200) is in the range of 1-5 μm, and the thickness of the embossing glue layer (300) is in the range of 5-50 μm.

8. The method for preparing a cell grid line (500) according to claim 1, characterized in that: The direction of the light is the extending direction of the protrusion.

9. A battery cell (100), characterized in that: It comprises a grid line formed on a surface, wherein the grid line is obtained by the method for preparing a grid line (500) for a battery cell according to any one of claims 1 to 8.

10. The battery cell (100) according to claim 9, characterized in that: The width of the gate line is in the range of 2-100 μm.

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