Cell grid line preparation method and cell

Abstract

The present application relates to a cell grid line preparation method, for use in achieving high-precision and high-efficiency preparation of grid lines by combining the advantages of photolithography and thermal imprinting technology. A photoresist layer and an imprint resist layer are sequentially formed on a cell; a transparent mold provided with a light-shielding layer and protrusions is used for thermal imprinting, so that first grooves can be formed in the imprint resist layer, and non-exposed areas are shielded by the light-shielding layer; and during thermal imprinting, areas corresponding to the first grooves in the photoresist layer are exposed, and then the exposed areas of the photoresist layer are removed to form second grooves. The imprint resist layer and the photoresist layer are immiscible, and the imprint resist layer is made of polylactic acid, thereby improving preparation precision and stability of grid lines. The cell grid lines prepared by the method have finely controlled width and height, and the method improves photoelectric conversion efficiency and stability of a solar cell, reduces the production costs, and is suitable for large-scale production.

Description

Methods for fabricating grid lines in solar cells and solar cells Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a method for preparing grid lines for a solar cell and a solar cell. Background Technology

[0002] In today's global energy structure, coal combustion remains a crucial power generation method. However, with rapid industrialization and a sharp increase in global energy consumption, the reserves of non-renewable resources such as coal are increasingly depleted. Even more serious is the severe negative impact of the extraction and use of these traditional energy sources on the natural environment, such as air pollution, greenhouse gas emissions, and water resource depletion. To address 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, with solar energy, as a clean and inexhaustible energy source, being considered one of the most promising alternatives.

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

[0004] Currently, the main industrial method for depositing electrodes onto photovoltaic cells is through printing technology. Screen printing, in particular, is widely used in large-scale industrial production due to its relatively low cost and mature process. However, a series of problems still need to be addressed during the electrode deposition process on silicon wafers using screen printing technology. First, insufficient printing precision is a significant issue. Due to the instability of printing parameters and various variations during the printing process, it is difficult to maintain a consistent width and thickness of the printed silver paste. This non-uniformity directly affects the resistance of the solar cell, thus adversely impacting its overall performance. Furthermore, screen printing technology struggles to achieve high-resolution printing of patterns smaller than 10μm, limiting the application of solar cells in more advanced fields. Second, material waste is another major challenge for screen printing technology. During the printing process, due to process limitations and improper operation, a large amount of waste material is often generated, leading to wasted silver paste and increased production costs. This not only hinders the economic benefits of enterprises but also violates the principles of sustainable development.

[0005] To address the aforementioned issues, although some alternatives such as RIE (Reactive Ion Etching) have been proposed, RIE faces significant challenges in industrialization, high costs, and numerous technical bottlenecks in practical applications, thus preventing its widespread adoption. Therefore, developing a novel method for fabricating solar cell grid lines and a new type of solar cell to overcome the shortcomings of existing technologies, improve printing accuracy, reduce material waste, and enhance production efficiency has become a crucial issue urgently needing to be addressed in the current solar cell field.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide a method for fabricating grid lines in solar cells, which can precisely control the size of the grid lines and simplify the fabrication process, realizing a high-resolution photovoltaic silver paste electrode imprinting method. The method for fabricating grid lines in solar cells of this application includes:

[0008] A photoresist layer is formed on the solar cell;

[0009] An imprinting adhesive layer is formed on the photoresist layer;

[0010] Using a transparent mold with a light-shielding layer and protrusions, a first groove is hot-pressed into the photoresist layer. The light-shielding layer blocks light outside the area corresponding to the first groove. At the same time as hot pressing, the area corresponding to the first groove in the photoresist layer is exposed.

[0011] The exposed area in the photoresist layer is removed, and a second groove is formed in the imprinting adhesive layer and the photoresist layer;

[0012] The second groove is filled with a conductive paste, and the conductive paste is then dried.

[0013] Remove the remaining photoresist layer and the imprinting adhesive layer;

[0014] The conductive paste is converted into battery cell grid lines;

[0015] The imprinting adhesive layer and the photoresist layer are immiscible.

[0016] In one embodiment, the step of filling the second groove with conductive paste further includes leveling the conductive paste with the upper surface of the imprinting adhesive layer by scraping.

[0017] In one embodiment, the material of the imprinting adhesive layer is polylactic acid.

[0018] In one embodiment, the photoresist layer and the imprinting adhesive layer are dissolved and removed simultaneously using the same solvent.

[0019] In one embodiment, the solvent is acetone.

[0020] In one embodiment, the width of the second groove is in the range of 2-100 μm.

[0021] In one embodiment, the thickness of the photoresist layer is in the range of 1-5 μm, and the thickness of the imprinting adhesive layer is in the range of 5-50 μm.

[0022] In one embodiment, the direction of the light is the direction of extension of the protrusion.

[0023] In addition, this application also provides a battery cell including grid lines formed on its surface, the grid lines being obtained by the aforementioned battery cell grid line preparation method.

[0024] In one embodiment, the width of the gate line is in the range of 2-100 μm.

[0025] Compared with existing technologies, this application has the following advantages: The method for fabricating grid lines in solar cells and the resulting solar cells provided in this application can achieve high-precision grid line fabrication compared to existing technologies. By combining hot stamping and UV lithography, a first groove is precisely hot-pressed into the photoresist layer using a transparent mold with a light-shielding layer and protrusions, while simultaneously exposing the photoresist layer, thereby achieving high-precision grid line fabrication. The width of the second groove can be controlled within the range of 2-100 μm, and the width and height of the grid lines can also be precisely adjusted, meeting the requirements of solar cells for grid line refinement and effectively improving the photoelectric conversion efficiency and performance stability of the cells.

[0026] To reduce material waste and lower costs, in the step of filling the second groove with conductive paste, the conductive paste is leveled with the upper surface of the imprinting adhesive layer by a scraping method. This not only ensures uniform distribution of the silver paste but also virtually eliminates the generation of silver paste waste, significantly reducing production costs. Furthermore, polylactic acid (PLA), as the imprinting adhesive layer material, possesses excellent film-forming properties and is immiscible with the photoresist layer, further ensuring that the silver paste maintains a good shape during curing, avoiding performance degradation due to shape differences. Without the need for complex RIE processes, the process can be directly performed on the silicon wafer, achieving gate line fabrication through simple thermal imprinting and photolithography steps. This greatly simplifies the process flow, and the method in this application can meet the needs of large-scale production, significantly improving production efficiency. Attached Figure Description

[0027] Figure 1 is a schematic diagram of the manufacturing process in an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 100, solar cell; 200, photoresist layer; 300, imprinting adhesive layer; 310, first groove; 320, second groove; 400, transparent mold; 500, solar cell grid line. Detailed Implementation

[0029] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0030] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] Traditional methods for fabricating solar cell grid lines 500, such as screen printing, while widely used in industry, still suffer from problems such as poor printing accuracy, material waste, and low production efficiency, limiting further improvements in solar cell performance. To overcome these technical bottlenecks, researchers and engineers are constantly exploring new technologies for fabricating solar cell grid lines 500, aiming to achieve more efficient, environmentally friendly, and economical solar cell production 100. This application proposes a method based on a combination of thermal embossing and UV lithography. This method combines thermal embossing, UV lithography, and advanced materials technology to achieve high-precision, low-cost, and environmentally friendly fabrication of grid lines. Please refer to Figure 1. A preferred embodiment of this application describes a method for fabricating a battery cell grid line 500, suitable for finely fabricating grid lines. The method includes: forming a photoresist layer 200 on a battery cell 100; forming an imprinting layer 300 on the photoresist layer 200; hot pressing with a transparent mold 400 having a light-shielding layer and protrusions; hot pressing a first groove 310 into the imprinting layer 300; the light-shielding layer blocking light from areas outside the corresponding region of the first groove 310; and simultaneously hot pressing... The area corresponding to the first groove 310 in the photoresist layer 200 is exposed, the exposed area in the photoresist layer 200 is removed, a second groove 320 is formed in the imprinting adhesive layer 300 and the photoresist layer 200, the second groove 320 is filled with conductive paste, and the conductive paste is dried; the remaining photoresist layer 200 and imprinting adhesive layer 300 are removed; the conductive paste is converted into a battery cell grid line 500; wherein the imprinting adhesive layer 300 and the photoresist layer 200 are immiscible.

[0033] First, a photoresist layer 200 is uniformly coated on the solar cell 100, serving as the basis for subsequent exposure and development. Next, an imprinting layer 300 is coated on top of the photoresist layer 200. This imprinting layer 300 must possess good hot-press deformation capabilities while ensuring that the two do not dissolve in each other during subsequent processing. Then, a transparent mold 400 with a light-shielding layer and protrusions is used to hot-press the imprinting layer 300. During hot pressing, the protrusions of the mold create a first groove 310 in the imprinting layer 300, while the light-shielding layer effectively blocks light from areas outside the corresponding regions of the first groove 310, preventing exposure in these areas. Simultaneously with hot pressing, a specific light source is used to precisely expose the area corresponding to the first groove 310 in the photoresist layer 200, causing a chemical reaction in the photoresist in that area, preparing it for subsequent removal. The transparent mold 400 can be made of PET or glass. Specifically, the unwanted areas can be etched out of the material to form a protrusion, or the protrusion can be attached to a whole layer of material to form the transparent mold 400.

[0034] After exposure, the exposed areas in the photoresist layer 200 are removed through a development process, thus forming a second groove 320 in both the photoresist layer 200 and the imprinting layer 300. The precision of this step is crucial for the final shape and size of the grid lines. Next, the second groove 320 is filled with conductive paste, and the paste is cured through a drying process. The selection of the conductive paste should meet the requirements of good conductivity and good adhesion to the substrate of the solar cell 100. After the conductive paste is dried, the remaining photoresist layer 200 and imprinting layer 300 are removed, exposing the cured conductive paste, i.e., the solar cell grid lines 500. This step is usually achieved by chemical or physical stripping, and the integrity and precision of the grid lines must be ensured. Further heat treatment or chemical treatment transforms the conductive paste into solar cell grid lines 500 with stable conductivity, which helps to improve the durability and reliability of the grid lines.

[0035] By combining photolithography and thermoimprinting techniques, the method of this application can precisely control the shape, size, and position of the grid lines, achieving high-precision grid line fabrication and thus improving the photoelectric conversion efficiency of solar cells. Compared with traditional methods for fabricating grid lines 500 in solar cells, this application reduces material waste and process complexity, lowering production costs. The immiscibility of the imprinting resist layer 300 and the photoresist layer 200 ensures their stability and independence in subsequent processing, providing a reliable guarantee for the fabrication of high-precision grid lines. In summary, the method for fabricating grid lines 500 in solar cells of this application exhibits significant technical advantages in terms of refined fabrication, cost control, environmental friendliness, and compatibility. Compared to using only thermoimprinting to form grooves, this application, by using the photoresist layer 200 as the bottom layer, can avoid residual imprinting resist on the surface of the solar cell by dissolving the photoresist, resulting in a cleaner surface for the solar cell where the grid lines are formed. Furthermore, the imprinting mold does not directly contact the surface of the solar cell, especially for the front side of the solar cell with a texturing structure and anti-reflection layer, minimizing the impact of impurities and contact. Compared to using only photoresist, this application can significantly reduce the amount of photoresist used. By using imprinting adhesive, which is cheaper and more readily available, and imprinting and photolithography can be formed in one step without secondary alignment, the method of this application strikes a good balance between manufacturing precision and manufacturing cost. This allows the application to achieve fine manufacturing of battery cell grid lines at a low cost, which has many advantages over traditional screen printing.

[0036] Specifically, the step of filling the second groove 320 with conductive paste further includes leveling the conductive paste with the upper surface of the imprinting adhesive layer 300 by a scraping method. In the step of filling the second groove 320 with conductive paste, the method of this application introduces a scraping process. This process uses a precision scraper or similar leveling tool to uniformly coat the conductive paste into the second groove 320, while ensuring that the paste surface is flush with the upper surface of the imprinting adhesive layer 300. During the scraping process, the conductive paste is precisely distributed to every corner of the second groove 320, avoiding paste waste and accumulation, and also ensuring the consistency and stability of the grid lines in subsequent processing. Furthermore, the leveling process helps eliminate minor unevenness on the surface of the paste, further improving the flatness and smoothness of the grid lines. This is crucial for improving the photoelectric conversion efficiency of solar cells. It not only improves the appearance quality of the grid lines but also reduces the increase in resistance caused by uneven paste distribution, thereby enhancing the photoelectric conversion efficiency of the solar cells. The high precision and controllability of the leveling process make the fabrication of the grid lines more stable and reliable, reducing variations in grid line size and shape caused by process fluctuations, and improving the consistency and reliability of the solar cells. A smooth grid line surface facilitates subsequent cleaning, drying, and curing steps, reducing processing difficulties and defects caused by surface unevenness, further improving the production efficiency and yield of solar cells. By introducing the leveling process, the method of this application achieves higher precision and stability in the step of filling the second groove 320 with conductive paste.

[0037] Specifically, the imprinted adhesive layer 300 is made of polylactic acid (PLA), also known as polylactide, a polyester polymer obtained by polymerization of lactic acid as the main raw material. It has good biodegradability and thermal stability. By applying silver paste to a silicon wafer with grooved PLA film and PR photoresist, the silver paste can maintain its original shape well during curing, resulting in almost no silver paste waste and reducing production costs. Furthermore, the imprinted adhesive layer 300 is made of poly(lactic-co-glycolic acid) (PLGA), which is randomly polymerized from two monomers—lactic acid and glycolic acid. It is a biodegradable functional polymeric organic compound with good biocompatibility, non-toxicity, and good encapsulation and film-forming properties.

[0038] Specifically, the photoresist layer 200 and the imprinting resist layer 300 are simultaneously dissolved and removed using the same solvent. By selecting a specific solvent that can effectively dissolve both the photoresist layer 200 and the imprinting resist layer 300, simultaneous removal of both is achieved in the same processing step. This step is typically performed after the conductive paste has been dried and converted into the cell grid lines 500, aiming to remove all non-conductive parts and expose the complete grid line structure. Through this simultaneous dissolution and removal technology, the two removal steps that would normally be performed separately are combined into one, greatly simplifying the process and improving production efficiency. Using the same solvent to simultaneously dissolve and remove the photoresist layer 200 and the imprinting resist layer 300 avoids waste and cross-contamination between different solvents.

[0039] Specifically, the solvent is acetone. PLA can be removed by organic solvents such as acetone, but it does not dissolve in weak alkalis, ensuring that it remains after the second step of removing part of the photoresist PR. Finally, the PR and PLA can be removed together by organic solvents such as acetone. To solve this problem of RIE, this solution uses a combination of thermal embossing and UV lithography, taking advantage of the different solubilities of polylactic acid and PR. PLA and PR photoresist will not react with the organic solvent in the silver paste to form adhesion, thus allowing the silver paste to maintain its shape well during the curing process and reducing the impact of different silver paste shapes on the performance of solar cells. Moreover, this method has a simple process flow, high process precision, and can be operated directly on the solar cell 100, enabling large-scale production.

[0040] Specifically, the width of the second groove 320 is in the range of 2-100 μm. In the fabrication of the solar cell grid line 500, this application precisely controls the width of the second groove 320, setting it within the range of 2-100 μm. This width range is selected based on in-depth research and comprehensive consideration of the solar cell's photoelectric conversion efficiency, current collection capability, and manufacturing cost. In actual operation, the width of the second groove 320 can be precisely controlled by adjusting parameters such as the size of the protruding portion of the imprinting mold, the imprinting pressure, imprinting time, and temperature. Simultaneously, it is also necessary to ensure that the thickness and uniformity of the photoresist layer 200 and the imprinting adhesive layer 300, as well as the interaction forces between them, are at their optimal state to guarantee the accuracy and consistency of the width of the second groove 320.

[0041] Specifically, the thickness of the photoresist layer 200 ranges from 1 to 5 μm, and the thickness of the imprinting layer 300 ranges from 5 to 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 and coating amount). A thinner photoresist layer 200 can reduce material consumption during exposure and development while ensuring sufficient resolution and contrast to form a clear gate pattern. The thickness of the imprinting layer 300 is controlled by adjusting parameters such as the protrusion height of the imprinting mold, the imprinting pressure, and the imprinting time. A thicker imprinting layer 300 can provide sufficient deformation capacity to accommodate the shape of the mold protrusion and form a precise second groove 320 during hot pressing. By precisely controlling the thickness of the photoresist layer 200 and the imprinting layer 300, the impact of process parameter fluctuations on gate fabrication can be reduced, improving the stability and reliability of the process. The thickness of the imprinting adhesive layer is preferably in the range of 8-20 μm. Within this range, the morphology of the imprinting adhesive layer is easier to control, which can further achieve precise control over the size and morphology of the gate lines and greatly improve the process stability.

[0042] Specifically, the direction of the light is the same as 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 imprinting 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 fabrication of the solar cell grid lines 500.

[0043] To improve the efficiency and accuracy of material discharge, the mold has an overflow channel located on the side of the protrusion. During the imprinting process, excess material can enter the overflow channel. Furthermore, it also includes an airflow channel connected to the overflow channel, through which pressure is provided. This airflow channel can also be used for detection and to provide a certain gas pressure. These airflow channels not only serve as auxiliary channels for material discharge, but also help to regulate and optimize the imprinting process by providing controllable gas pressure.

[0044] In addition, this application also provides a battery cell 100, including grid lines formed on its surface, the grid lines being obtained by the aforementioned battery cell grid line 500 preparation method.

[0045] Specifically, the width of the grid lines is in the range of 2-100 μm, and more specifically, the width is selected to be in the range of 2-10 μm. The fabrication method of this application can precisely achieve the fabrication of grid lines within this size range. Additionally, the height of the grid lines is in the range of 10-50 μm, and more preferably, the height is in the range of 8-25 μm. Through the manufacturing method of this application, the width and height of the grid lines can be controlled within a fine range, thereby improving the efficiency and stability of the solar cell 100.

[0046] The technical solution of this application will be further explained below with a specific embodiment. This application first coats a 1-3 μm layer of PR photoresist onto the solar cell. After the PR photoresist cures, a 9-10 μm layer of PLA film is coated on top. Then, a transparent mold with a light-shielding layer is used to hot-press out the required height and width for coating silver paste. Since there is still 1-2 μm of PR photoresist bonded to the silicon wafer at this point, the silver paste cannot directly contact the silicon wafer. Therefore, while hot-pressing, the PR photoresist is irradiated with a UV lamp, and then the irradiated PR photoresist is cleaned away with a developer until all residual PR photoresist on the grooves is removed, exposing the silicon wafer and forming a high-precision groove pattern. Silver paste is poured onto the grooved silicon wafer and smoothed out. Then, it is placed in an oven to dry the silver paste. After the silver paste is dried, the silicon wafer with the silver paste is placed in an organic solvent (such as acetone) to dissolve the PLA and PR photoresist on the silicon wafer simultaneously. Finally, the silver paste is sintered.

[0047] As described above, this application proposes a novel method for fabricating grid lines in solar cells. This method combines the advantages of photolithography and thermoimprinting techniques to achieve high-precision and high-efficiency fabrication of grid lines. The method includes the following key steps: First, a photoresist layer with a thickness ranging from 1 to 5 μm is uniformly coated on the solar cell. This photoresist layer serves as the basis for subsequent exposure and development. Next, an imprinting layer with a thickness ranging from 5 to 50 μm is coated on top of the photoresist layer. This imprinting layer is made of polylactic acid (PLA), possessing good thermoforming capabilities while ensuring that it does not dissolve in the photoresist layer during subsequent processing. The imprinting layer is then thermopressed using a transparent mold with a light-shielding layer and protrusions. During the thermopressing process, the protrusions of the mold create a first groove in the imprinting layer, while the light-shielding layer effectively blocks light from areas outside the corresponding first groove, preventing exposure in these areas. During hot pressing, a specific light source is used to precisely expose the area corresponding to the first groove in the photoresist layer, causing a chemical reaction in the photoresist in that area, preparing it for subsequent removal. It is worth noting that the incident direction of the light is consistent with the extension direction of the protrusion, thereby improving alignment accuracy and process efficiency.

[0048] After the conductive paste is dried, the remaining photoresist and imprinting adhesive layers are removed using organic solvents such as acetone, exposing the cured conductive paste, i.e., the cell grid lines. Acetone, as a solvent, effectively dissolves both the photoresist and imprinting adhesive layers simultaneously, allowing for their removal in the same processing step, greatly simplifying the process and improving production efficiency. Further heat or chemical treatment transforms the conductive paste into cell grid lines with stable conductivity. The grid line width is controlled within the range of 2-100 μm, and the height within the range of 10-50 μm; such precise dimensions contribute to improving the photoelectric conversion efficiency and stability of the solar cell.

[0049] In summary, the solar cell grid line fabrication method of this application exhibits significant technical advantages in terms of refined fabrication, cost control, environmental friendliness, and compatibility. This method can precisely control the shape, size, and position of the grid lines, achieving high-precision grid line fabrication, thereby improving the photoelectric conversion efficiency of solar cells. Simultaneously, this method reduces material waste and process complexity, lowering production costs and providing strong support for the large-scale production of solar cells. Using this method, very fine patterns (2-10 μm wide) can be coated on silicon wafers, while precisely controlling the thickness of the coated silver paste, ensuring that the performance of the solar cell is not degraded due to uneven silver paste thickness. Furthermore, the method of this application generates almost no waste, greatly saving on the cost of silver paste usage.

[0050] The above is only one specific implementation of this application, and any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. A method for preparing grid lines (500) of a solar cell, characterized in that, include: A photoresist layer (200) is formed on the solar cell (100); An imprinting layer (300) is formed on the photoresist layer (200); Using a transparent mold (400) with a light-shielding layer and protrusions, a first groove (310) is hot-pressed in the imprinting adhesive layer (300). The light-shielding layer blocks light outside the area corresponding to the first groove (310). At the same time as hot pressing, the area corresponding to the first groove (310) in the photoresist layer (200) is exposed. The exposed area in the photoresist layer (200) is removed, and a second groove (320) is formed in the imprinting adhesive layer (300) and the photoresist layer (200); The second groove (320) is filled with a conductive paste, and the conductive paste is dried. Remove the remaining photoresist layer (200) and the imprinting adhesive layer (300); The conductive paste is converted into battery cell grid lines (500); The imprinting adhesive layer (300) and the photoresist layer (200) are immiscible.

2. The method for preparing the battery cell grid line (500) according to claim 1, characterized in that, The step of filling the second groove (320) with conductive paste further includes leveling the conductive paste with the upper surface of the embossing adhesive layer (300) by scraping.

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

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

6. The method for preparing the battery 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 the battery 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 imprinting adhesive layer (300) is in the range of 5-50 μm.

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

9. A battery cell (100), characterized in that, Includes grid lines formed on the surface, said grid lines being obtained by the cell grid line (500) preparation method according to any one of claims 1-8.

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

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