Battery preparation method and battery

Abstract

The invention discloses a battery preparation method and a battery, which are applied to the photovoltaic field, and comprises the following steps: providing a battery prefabricated member; performing film opening treatment on the back surface of the battery prefabricated member; preparing a front conductive electrode on the front surface of the battery prefabricated member; connecting a conductive electrode contact area exposed on the back surface of the processed to-be-processed battery structure with a back surface conductive structure, and connecting a front surface conductive electrode with a front surface conductive structure; and processing the to-be-processed battery structure by using a laser enhanced contact optimization technology, and preparing a back conductive electrode to obtain the battery. According to the invention, the back surface of the battery prefabricated member is subjected to the film opening treatment, and the conductive electrode contact area exposed through the film opening treatment is connected with the back surface conductive structure, so that the laser enhanced contact optimization treatment is carried out when the conductive electrode is not prepared on the back surface of the battery prefabricated member, and the flexibility of the laser enhanced contact optimization process is improved; and meanwhile, the current lead-out efficiency of the battery is improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaics, and in particular to a method for preparing a battery and the battery itself. Background Technology

[0002] LECO technology (Laser Enhanced Contact Optimization) involves irradiating a solar cell with a high-intensity laser while simultaneously applying a reverse voltage of 10V or higher. The laser scans the cell, exciting charge carriers. These free charge carriers are forced through the metal-semiconductor contact point, generating a high current of several amperes that flows through a very small, locally conductive point, significantly reducing the contact resistance between the metal and semiconductor. In conventional LECO equipment, when a constant reverse voltage is applied, the front of the cell is in contact with the probe array, while the back is in full contact with the metal platform. Since the reverse voltage cannot conduct when no electrodes are fabricated on the back of the cell, LECO technology must be performed after conductive electrodes are fabricated on the back of the cell, which limits the flexibility of cell fabrication.

[0003] Therefore, how to provide a flexible process for setting up LECO technology while using LECO technology to reduce the contact resistance between metal and semiconductor is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a battery manufacturing method and a battery, which solves the problem that in the prior art, the reverse voltage cannot be conducted when no electrode is prepared on the back of the battery, so the LECO technology needs to be set after the conductive electrode is prepared on the back of the battery cell, which affects the flexibility of battery manufacturing.

[0005] To solve the above-mentioned technical problems, the present invention provides a battery manufacturing method, comprising:

[0006] A battery preform is provided, the battery preform including a substrate, wherein passivation functional layers are formed on both sides of the substrate;

[0007] The back of the battery preform is opened to expose the conductive electrode contact area on the back of the battery preform.

[0008] A front conductive electrode is prepared on the front side of the battery preform;

[0009] The conductive electrode contact area on the back side of the battery structure to be processed is connected to the back conductive structure, and the front conductive electrode is connected to the front conductive structure; the battery structure to be processed is a structure in which the front conductive electrode is prepared on the front side of the battery preform and the conductive electrode contact area is exposed on the back side of the battery preform.

[0010] The front conductive structure and the back conductive structure are used as the two poles to apply voltage, and the battery structure to be processed is processed using laser-enhanced contact optimization technology;

[0011] Prepare a back conductive electrode.

[0012] Optionally, the battery preform is a TOPCon battery preform;

[0013] The preparation of the back conductive electrode includes:

[0014] Using an electroplating process, the back conductive electrode is formed in the conductive electrode contact area on the back side of the battery structure to be treated, which has been treated with laser-enhanced contact optimization technology.

[0015] Optionally, after processing the battery structure to be processed using laser-enhanced contact optimization technology, and before forming the back conductive electrode in the conductive electrode contact area on the back side of the battery structure to be processed using an electroplating process, the method further includes:

[0016] The battery structure to be treated, which has been treated with laser-enhanced contact optimization technology, is subjected to electroplating pretreatment to remove surface impurities and increase the surface roughness of the battery structure to be treated.

[0017] Optionally, the battery preform is a TOPCon battery preform;

[0018] A front conductive electrode is fabricated on the front side of the battery preform, including:

[0019] A front conductive electrode is prepared on the front side of the battery preform using a screen printing process.

[0020] Optionally, negative pressure adsorption can be used to connect the conductive electrode contact area on the back of the battery structure to be treated to the back conductive structure.

[0021] Optionally, the back side of the battery preform is subjected to a film-opening process to expose the conductive electrode contact area on the back side of the battery preform, including:

[0022] Laser-assisted delamination is used to delaminate the back of the battery preform, specifically the area corresponding to the grid lines and the area where electroplating clips are located, to expose the conductive electrode contact area on the back of the battery preform.

[0023] Optionally, the back conductive structure is a flexible conductive layer.

[0024] Optionally, the front conductive structure is a metal probe.

[0025] The present invention also provides a battery comprising:

[0026] The substrate, passivation functional layers on both sides of the substrate, and front conductive electrodes and back conductive electrodes disposed on both sides aligned with the substrate.

[0027] The back conductive electrode is prepared by connecting the conductive electrode contact area on the back side of the battery structure to be processed to the back conductive structure, connecting the front conductive electrode to the front conductive structure, using the front conductive structure and the back conductive structure as the two poles for applying voltage, and processing the battery structure to be processed using laser-enhanced contact optimization technology. The battery structure to be processed is prepared by fabricating the front conductive electrode on the front side of the battery preform, and performing a film-opening process on the back side of the battery preform to expose the structure of the conductive electrode contact area. The battery preform includes a substrate and the passivation functional layer.

[0028] Optionally, the back conductive structure is a flexible conductive layer;

[0029] The flexible conductive layer has through holes to allow negative pressure adsorption to connect the conductive electrode contact area on the back of the battery structure to be processed to the flexible conductive layer.

[0030] As can be seen, the battery fabrication method provided by the present invention includes providing a battery preform, the battery preform including a substrate, both sides of which are prepared with passivation functional layers; performing a film-opening process on the back side of the battery preform to expose the conductive electrode contact area on the back side of the battery preform; preparing a front conductive electrode on the front side of the battery preform; connecting the conductive electrode contact area on the back side of the battery structure to be processed to a back conductive structure; and connecting the front conductive electrode to the front conductive structure. The battery structure to be processed is a structure in which the front conductive electrode is prepared on the front side of the battery preform, and the conductive electrode contact area is exposed on the back side of the battery preform. The front conductive structure and the back conductive structure are used as the two poles for applying voltage. Laser-enhanced contact optimization technology is used to process the battery structure to be processed to prepare the back conductive electrode. The present invention improves the flexibility of the laser-enhanced contact optimization process and improves the current extraction efficiency of the battery by performing a film-opening process on the back side of the battery preform to expose the conductive electrode contact area on the back side of the battery preform and connecting the conductive electrode contact area to the back conductive structure, so as to perform laser-enhanced contact optimization processing when the conductive electrode is not prepared on the back side of the battery preform.

[0031] In addition, the present invention also provides a battery that has the same beneficial effects as described above. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 A flowchart of a battery manufacturing method provided in an embodiment of the present invention;

[0034] Figure 2 An example diagram of the area on the back of a battery preform corresponding to the electroplating pinch point after the film is opened, as provided in an embodiment of the present invention;

[0035] Figure 3 This is an example diagram of a structure for laser-enhanced contact optimization technology processing of a battery structure to be processed, provided by an embodiment of the present invention;

[0036] Figure 4 This is an example diagram of another structure for laser-enhanced contact optimization technology processing of the battery structure to be processed, provided by an embodiment of the present invention;

[0037] Figures 1 to 4 The reference numerals in the attached figures are explained as follows:

[0038] 10 - Double-sided passivated blue film, 21 - Area for opening film treatment corresponding to grid lines, 22 - Area for opening film treatment corresponding to electroplating pinch points, 30 - Front conductive electrode, 40 - LECO equipment process table, 50 - Flexible conductive layer, 60 - Through hole. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please refer to Figure 1 , Figure 1 A flowchart illustrating a battery fabrication method provided in an embodiment of the present invention. The method may include:

[0041] S101: Provides a battery preform, which includes a substrate, on both sides of which a passivation functional layer is prepared.

[0042] The execution subject of this embodiment is a battery fabrication device. In this embodiment, the battery preform is a structure in which passivation functional layers are completed on both sides of the substrate, that is, the battery preform is the structure for which conductive electrodes need to be fabricated in the next process.

[0043] S102: Perform a film-opening process on the back side of the battery preform to expose the conductive electrode contact area on the back side of the battery preform.

[0044] It should be noted that the "front" and "back" mentioned in this embodiment refer to the front and back of the workpiece during the LECO process, and are not necessarily equivalent to the front and back of the fabricated battery cell. For example, when the battery preform is placed on the equipment's process table for the LECO process, the side of the battery preform that will subsequently be mounted against the equipment's process table is designated as the back, and the side of the battery preform that will subsequently be mounted away from the equipment's process table is designated as the front. This embodiment does not limit the specific method of performing the film-opening process on the back of the battery preform, as long as it is possible to perform the film-opening process on the corresponding area of ​​the back of the battery preform. For example, the film-opening process on the back of the battery preform can be performed by etching, or it can be performed by laser grooving. This embodiment also does not limit the specific execution parameters for performing the film-opening process on the back of the battery preform, as long as at least part of the passivation functional layer located on the back of the substrate is removed to expose the area for connecting conductive electrodes.

[0045] S103: Prepare a front conductive electrode on the front side of the battery preform.

[0046] In this embodiment, a front conductive electrode is prepared on the front side of the battery preform to facilitate conductive connection with an external circuit during the subsequent LECO process. Furthermore, this embodiment executes the film-opening process in step S102 first, followed by the preparation of the front conductive electrode in step S103. However, in practice, the preparation of the front conductive electrode in step S103 can also be performed first, followed by the film-opening process in step S102.

[0047] S104: Connect the conductive electrode contact area on the back side of the battery structure to be processed to the back conductive structure, and connect the front conductive electrode to the front conductive structure; the battery structure to be processed is a structure in which the front conductive electrode is prepared on the front side of the battery preform and the conductive electrode contact area is exposed on the back side of the battery preform.

[0048] In this embodiment, the front of the battery preform is fabricated with a front conductive electrode, and the back is exposed with the conductive electrode contact area. This structure serves as the battery structure to be processed. The front conductive electrode is conductively connected to the front conductive structure, and the back of the battery structure is exposed with the conductive electrode contact area and connected to the back conductive structure. The front and back conductive structures are connected to an external power supply module to complete the preparation before performing the LECO process. Accordingly, in this embodiment, the side of the battery structure to be processed that faces the equipment process table is designated as the back of the battery structure, and the side of the battery structure to be processed that faces away from the equipment process table is designated as the front of the battery structure.

[0049] S105: The front conductive structure and the back conductive structure are used as the two poles to apply voltage, and the battery structure to be treated is processed using laser-enhanced contact optimization technology.

[0050] It should be noted that in this embodiment, the structure prepared in step S104 above is used to apply a reverse voltage to the battery structure to be processed by an external power supply module, and the battery structure to be processed is processed by laser enhanced contact optimization technology to complete the LECO process for the battery structure to be processed with a single front conductive electrode.

[0051] S106: Fabrication of the back conductive electrode.

[0052] After the LECO process is completed on the battery structure to be processed with a front conductive electrode on one side, a back conductive electrode needs to be prepared in the contact area of ​​the conductive electrode to complete the battery preparation.

[0053] Furthermore, in order to ensure the smooth completion of battery fabrication, the aforementioned battery preform can be set as a TOPCon battery preform;

[0054] Accordingly, the steps for preparing the back conductive electrode described above may include:

[0055] Using an electroplating process, a back conductive electrode is formed in the conductive electrode contact area on the back of the battery structure to be treated, which has been treated with laser-enhanced contact optimization technology.

[0056] In this embodiment, the battery preform is set as a TOPCon battery preform, that is, a TOPCon battery is prepared using the above method. Since the junction of the light-receiving surface of the TOPCon battery is too close to the surface, the damage to the conductive electrodes prepared using grooving methods such as electroplating and laser plating combined with electroplating is too great. However, the back surface of the TOPCon battery is suitable for grooving methods such as electroplating and laser plating combined with electroplating to prepare conductive electrodes. Therefore, the conductive electrodes on both sides of the TOPCon battery need to be prepared separately. Thus, in this embodiment, an electroplating process can be used on the back of the TOPCon battery to prepare the back conductive electrode in the contact area of ​​the already formed conductive electrode. It should be noted that in this embodiment, after performing the LECO process, the contact resistance between the front conductive electrode and the battery preform is optimized. Especially when the front conductive electrode is a metal conductive electrode, the LECO process optimization can effectively improve the contact resistance between the metal conductive electrode and the semiconductor structure, thereby improving the current extraction efficiency of the finally prepared battery. Furthermore, this invention utilizes an electroplating process to fabricate a back conductive electrode in the contact area of ​​the conductive electrode on the back side of the battery structure to be treated, which has undergone laser-enhanced contact optimization technology. By optimizing the contact resistance between the front conductive electrode and the battery preform, the yield rate of electroplating for fabricating the back conductive electrode is improved. In this embodiment, when fabricating the back conductive electrode using the electroplating process, electroplating clamps need to be created, and the area 22 corresponding to the electroplating clamps undergoing film-opening treatment can be referenced... Figure 2 , Figure 2 This is an example diagram showing the unwrapped area on the back side of a battery preform corresponding to an electroplating clamp point, provided in an embodiment of the present invention. The area 22 where the unwrapping process is performed corresponding to the electroplating clamp point can be as follows... Figure 2 As shown in the diagram. In this embodiment, the conductive electrodes on the back of the battery are subsequently fabricated by electroplating. Therefore, after the film-opening process, the contact area of ​​the conductive electrodes on the back of the battery preform is exposed. This serves two purposes: firstly, it allows for the optimization of the contact resistance between the front of the battery and the conductive electrodes using the LECO process; secondly, the exposed contact area is also used for subsequent electroplating to fabricate the conductive electrodes on the back. In this embodiment, the length and width of the film-opening area corresponding to the electroplating clamps can be set between 3 mm and 5 mm.

[0057] Furthermore, to improve the yield of electroplating treatment, after processing the battery structure using laser-enhanced contact optimization technology, and before forming the back conductive electrode in the conductive electrode contact area on the back of the battery structure treated with laser-enhanced contact optimization technology using electroplating, the process may further include:

[0058] The battery structure to be treated, which has been treated with laser-enhanced contact optimization technology, is subjected to electroplating pretreatment to remove surface impurities and increase the surface roughness of the battery structure.

[0059] It should be noted that in this embodiment, the battery structure to be processed using laser-enhanced contact optimization technology undergoes electroplating pretreatment. The purpose is to remove impurities from the battery surface and increase its surface roughness. This improves the conductivity of the back conductive electrode prepared by electroplating, while also facilitating the metal electroplating process and increasing battery manufacturing efficiency. After processing the battery structure using laser-enhanced contact optimization technology, before fabricating the battery, it is necessary to separate the conductive electrode contact area from the back conductive structure and separate the front conductive electrode from the front conductive structure.

[0060] Furthermore, in order to improve the yield of finished battery products, the aforementioned battery preform can be configured as a TOPCon battery preform.

[0061] Fabricating a front conductive electrode on the front side of a battery preform may include:

[0062] A front conductive electrode is prepared on the front side of a battery preform using a screen printing process.

[0063] It should be noted that in this embodiment, the front conductive electrode is prepared on the front side of the battery preform using screen printing technology. This avoids junction damage on the light-receiving surface of the TOPCon battery, ensuring a high yield rate. In this embodiment, the front side of the workpiece is equivalent to the light-receiving surface of the TOPCon battery.

[0064] Furthermore, to improve the ease of performing the LECO process, negative pressure adsorption can be used to connect the conductive electrode contact area on the back of the battery structure to be treated with the conductive structure on the back.

[0065] In this embodiment, negative pressure adsorption is used to connect the conductive electrode contact area on the back of the battery structure to be treated with the conductive structure on the back, which facilitates the connection between the conductive electrode contact area on the back of the battery structure to be treated and the conductive structure on the back, and ensures the stability of the LECO process.

[0066] Furthermore, to improve the efficiency of the film-opening process on the back side of the battery preform, the aforementioned film-opening process on the back side of the battery preform to expose the conductive electrode contact area on the back side of the battery preform may include:

[0067] Laser-assisted delamination is used to delaminate the back of the battery preform, specifically the areas corresponding to the grid lines and the areas where electroplating clips are located, in order to expose the conductive electrode contact areas on the back of the battery preform.

[0068] It should be noted that in this embodiment, the back of the battery preform is opened using a laser film-opening process to expose the conductive electrode contact area on the back of the battery preform, thereby improving the efficiency of the film-opening process and thus improving the battery manufacturing efficiency.

[0069] Furthermore, in order to improve the matching connection between the back conductive structure and the battery structure to be processed, the back conductive structure can be set as a flexible conductive layer.

[0070] It should be noted that in this embodiment, the back conductive structure is set as a flexible conductive layer, which can ensure effective contact between the back conductive structure and the conductive electrode contact area on the back of the battery structure to be processed, ensuring the contact area, while reducing the stress on the contact surface between the two and avoiding damage to the battery structure to be processed.

[0071] Furthermore, in order to improve the matching connection between the front conductive structure and the battery structure to be processed, the aforementioned front conductive structure can be set as a metal probe.

[0072] In this embodiment, the front conductive structure is set as a metal probe and connected to the front conductive electrode to ensure the LECO process can proceed.

[0073] The battery fabrication method provided in this invention includes providing a battery preform, which includes a substrate. Passivation functional layers are formed on both sides of the substrate. A film-opening process is performed on the back side of the battery preform to expose the conductive electrode contact area. A front conductive electrode is formed on the front side of the battery preform. The conductive electrode contact area on the back side of the battery structure to be processed is connected to a back conductive structure, and the front conductive electrode is connected to the front conductive structure. The battery structure to be processed has a front conductive electrode formed on the front side of the battery preform and a conductive electrode contact area exposed on the back side. The front and back conductive structures are used as the two poles for applying voltage. Laser-enhanced contact optimization technology is used to process the battery structure to be processed and form the back conductive electrode. This invention improves the flexibility of the laser-enhanced contact optimization process and increases the current extraction efficiency of the battery by performing a film-opening process on the back side of the battery preform to expose the conductive electrode contact area and connecting this contact area to the back conductive structure. This allows for laser-enhanced contact optimization even when no conductive electrode is formed on the back side of the battery preform, thus improving the flexibility of the laser-enhanced contact optimization process and simultaneously increasing the current extraction efficiency of the battery.

[0074] Furthermore, this embodiment of the invention utilizes an electroplating process to fabricate a back conductive electrode in the contact area of ​​the conductive electrode on the back side of the battery structure to be treated, which has undergone laser-enhanced contact optimization technology. By optimizing the contact resistance between the front conductive electrode and the battery preform, the electroplating of the back conductive electrode facilitates current conduction in the battery structure, improving the yield rate of electroplating. Pre-treating the battery structure to be treated with laser-enhanced contact optimization technology by electroplating improves the conductivity of the back conductive electrode and also enhances the convenience of metal electroplating, thereby increasing battery fabrication efficiency. Using screen printing to fabricate the front conductive electrode on the front side of the battery preform avoids junction damage to the light-receiving surface of the TOPCon battery. To ensure battery yield, negative pressure adsorption is used to connect the conductive electrode contact area on the back of the battery structure to the back conductive structure, ensuring the stability of the LECO process. Laser-assisted film-opening is used to open the back of the battery preform to expose the conductive electrode contact area, improving the efficiency of the film-opening process and thus increasing battery fabrication efficiency. The back conductive structure is set as a flexible conductive layer, ensuring effective contact between the back conductive structure and the conductive electrode contact area on the back of the battery structure, maximizing the contact area while reducing stress on the contact surface and preventing damage to the battery structure. The front conductive structure is set as a metal probe, correspondingly connected to the front conductive electrode, ensuring the compatibility between the front conductive structure and the front conductive electrode.

[0075] In one feasible implementation, the above-described battery fabrication method can be referred to... Figure 3 and Figure 4 , Figure 3 This is an example diagram of a structure for laser-enhanced contact optimization technology processing of a battery structure to be processed, provided by an embodiment of the present invention. Figure 4 This is an example diagram of another structure for laser-enhanced contact optimization technology processing of a battery structure to be processed, provided as an embodiment of the present invention. Specifically, it may include the following steps:

[0076] Step S1: Double-sided passivated blue film 10 is prepared by sequentially performing double-sided texturing, boron diffusion, removal of back side BSG (borosilicate glass), alkaline polishing, back side LP (low-pressure chemical vapor deposition, used to prepare polycrystalline silicon layer) + phosphorus diffusion, removal of PSG (phosphosilicate glass), front side ALD (atomic layer deposition), and front and back PE processes.

[0077] It should be noted that the fabrication process in this embodiment can be performed using conventional methods for preparing Topcon battery structures. The front and back PE processes are passivation treatments performed on the front and back sides of the battery cells.

[0078] Step S2: Using laser etching process, slurry etching process, patterned mask combined with chemical etching process, or ion etching process, the back side of the double-sided passivated blue film 10 is subjected to etching process, corresponding to the grid lines and the areas where electroplating pinch points are set, so as to expose the conductive electrode contact area on the back side of the double-sided passivated blue film 10.

[0079] It should be noted that when using laser-based film-opening technology to open the back side of the double-sided passivated blue film 10, specifically the areas corresponding to the grid lines and the electroplating clamping points, the laser wavelength must be 266 nm, 355 nm, or 532 nm; the pulse width must be nanoseconds or picoseconds; the spot size must be between 3 μm and 100 μm; the overlap rate must be less than 10% to 50% (separation is not allowed); and the reference power must be between 0.1 W and 4 W. The specific processing method can be configured as one or more lasers used for single or multiple opening operations. The areas 21 corresponding to the grid lines and 22 corresponding to the electroplating clamping points can be referenced... Figure 3 and Figure 4 .

[0080] Step S3: Prepare a front conductive electrode 30 on the front side of the double-sided passivated blue film 10.

[0081] Step S4: Place the double-sided passivated blue film 10 on the process table 40 of the LECO equipment. The back side of the double-sided passivated blue film 10 is in contact with the flexible conductive layer 50 on the process table 40 of the LECO equipment, so that the flexible conductive layer 50 is in contact with the conductive electrode contact area on the back side. The front conductive electrode 30 on the front side of the double-sided passivated blue film 10 is in contact with the metal electrode probe array in the LECO equipment. A reverse voltage is applied to the double-sided passivated blue film 10 through the metal electrode probe array and the flexible conductive layer 50. The double-sided passivated blue film 10 is processed using laser-enhanced contact optimization technology.

[0082] It should be noted that the flexible conductive layer 50 can be made of materials such as conductive silicone, graphene, or conductive cotton. The LECO equipment process table 40 is also provided with through holes 60. The through holes 60 can form positive or reverse air pressure to adsorb or release the battery cells. The applied reverse voltage is required to be greater than 10V. The size of the laser spot, the spot energy, the scanning method, etc. are determined according to the requirements of different laser manufacturers. This application does not make any special requirements. Figure 3 and Figure 4 These are side cross-sectional views of the double-sided passivated blue film 10 placed on the process table 40 of the LECO equipment from different directions when the battery structure to be treated is subjected to laser enhanced contact optimization technology.

[0083] Step S5: The double-sided passivated blue film 10, which has undergone laser-enhanced contact optimization technology, is immersed once or multiple times using a solution containing two or more of the following: ammonium fluoride, hydrofluoric acid, water, corrosion inhibitor, hydrochloric acid, sulfuric acid, palladium chloride, stannous chloride, and sodium stannate. The pH value of the solution is set between 1 and 6, the treatment time is between 10 and 60 seconds, the treatment temperature is between 20 and 80 degrees Celsius, and the change in reflectivity before and after treatment is less than 5%.

[0084] Step S6: Electroplating nickel, copper, silver or tin onto the conductive electrode contact area on the back side of the double-sided passivated blue film 10.

[0085] In this embodiment, the same group of solar cells, whether pre-treated with LECO plating or not, are uniformly subjected to IV testing, as shown in Table 1 below:

[0086] line labels Eta FF Isc Voc Rs Rsh Maximum value - Eta Maximum value - FF Maximum value - Isc Maximum value - Voc BSL (same batch) 26.3176 85.5762 13.8702 0.7320 -0.0007 2946.3798 G1-LECO 26.1219 84.7673 13.8996 0.7320 -0.0004 1343.0859 26.2553 85.0654 13.9019 0.7338 G2 - No LECO 25.5579 83.8569 13.8969 0.7240 -0.0001 907.6132 25.9038 84.4039 13.9017 0.7289

[0087] The BSL (same batch) mentioned above refers to test samples within the same batch. Eta is the photoelectric conversion efficiency of the cell, FF is the fill factor, Isc is the short-circuit current, Voc is the open-circuit voltage, Rs is the series resistance, and Rsh is the parallel resistance. As can be seen from the table above, the cells pre-treated with LECO and then electroplated exhibit better Eta, Voc, maximum value -Eta, maximum value -FF, and maximum value -Voc.

[0088] The battery provided in the embodiments of the present invention will be described below. The battery described below and the battery preparation method described above can be referred to each other.

[0089] The battery provided in this embodiment of the invention may include:

[0090] The substrate, passivation functional layers on both sides of the substrate, and front conductive electrodes and back conductive electrodes disposed on both sides aligned with the substrate.

[0091] The back conductive electrode is prepared by connecting the conductive electrode contact area on the back side of the battery structure to be processed to the back conductive structure, connecting the front conductive electrode to the front conductive structure, and using the front and back conductive structures as the two poles for applying voltage. The back conductive electrode is prepared by processing the battery structure to be processed using laser-enhanced contact optimization technology. The battery structure to be processed is prepared by fabricating the front conductive electrode on the front side of the battery preform and performing a film-opening process on the back side of the battery preform to expose the structure of the conductive electrode contact area. The battery preform includes a substrate and a passivation functional layer.

[0092] In this embodiment, the battery is prepared using the battery preparation method described above, resulting in the structure shown above, which improves the current extraction efficiency and yield of the battery.

[0093] Furthermore, in order to ensure a stable connection between the back conductive structure in the conductive structure connection component and the contact area of ​​the conductive electrode on the back of the battery structure to be processed, the back conductive structure can be set as a flexible conductive layer.

[0094] The flexible conductive layer has through holes to allow the conductive electrode contact area on the back of the battery structure to be treated to be connected to the flexible conductive layer by negative pressure adsorption through the through holes.

[0095] In this embodiment, the back conductive structure is set as a flexible conductive layer, ensuring effective contact between the back conductive structure and the contact area of ​​the conductive electrode on the back of the battery structure to be processed, increasing the contact area, and thus ensuring contact resistance. Furthermore, this embodiment of the invention provides through-holes in the flexible conductive layer and uses negative pressure adsorption to adsorb and fix the contact area of ​​the conductive electrode on the back of the battery structure to be processed to the flexible conductive layer. This ensures a stable connection between the contact area of ​​the conductive electrode on the back of the battery structure to be processed and the flexible conductive layer during the LECO process, guaranteeing the stable completion of the LECO process. The through-holes in the flexible conductive layer in this embodiment can be used to apply reverse and forward air pressure to adsorb and fix the contact area of ​​the conductive electrode to the flexible conductive layer, or to separate the contact area of ​​the conductive electrode to the flexible conductive layer. In this embodiment, the flexible conductive layer can be selected from conductive silicone, graphene, or conductive cotton, or other materials can be used. Other methods can also be used to separate the flexible conductive layer in this embodiment, such as heating the platform to soften the flexible conductive layer for easier separation.

[0096] The battery provided in the embodiments of the present invention includes

[0097] The invention comprises a substrate, passivation functional layers on both sides of the substrate, and front and back conductive electrodes correspondingly disposed on both sides of the substrate. The back conductive electrode is formed by connecting the contact area of ​​the conductive electrode on the back side of the battery structure to be processed to the back conductive structure, and connecting the front conductive electrode to the front conductive structure. The front and back conductive structures serve as the two poles for applying voltage. The back conductive electrode is prepared by processing the battery structure to be processed using laser-enhanced contact optimization technology. The battery structure to be processed consists of a front conductive electrode prepared on the front side of the battery preform, and a film-opening process performed on the back side of the battery preform to expose the structure of the conductive electrode contact area. The battery preform includes a substrate and a passivation functional layer. This invention exposes the contact area of ​​the conductive electrode on the back side of the battery preform by performing a film-opening process on the back side of the battery preform and connecting this contact area to the back conductive structure. This allows for laser-enhanced contact optimization processing when no conductive electrode is prepared on the back side of the battery preform, improving the flexibility of the laser-enhanced contact optimization process and simultaneously improving the current extraction efficiency of the battery.

[0098] Furthermore, by setting the back conductive structure as a flexible conductive layer, this embodiment of the invention ensures effective contact between the back conductive structure and the contact area of ​​the conductive electrode on the back of the battery structure to be processed, thereby increasing the contact area and ensuring the contact resistance. By setting through holes in the flexible conductive layer and using negative pressure adsorption through the through holes, a stable connection between the contact area of ​​the conductive electrode on the back of the battery structure to be processed and the flexible conductive layer is ensured.

[0099] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0100] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0101] The present invention has provided a detailed description of a battery preparation method and a battery. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing a battery, characterized in that, include: A battery preform is provided, the battery preform including a substrate, wherein passivation functional layers are formed on both sides of the substrate; The back of the battery preform is opened to expose the conductive electrode contact area on the back of the battery preform. A front conductive electrode is prepared on the front side of the battery preform; The conductive electrode contact area on the back side of the battery structure to be processed is connected to the back conductive structure, and the front conductive electrode is connected to the front conductive structure; the battery structure to be processed is a structure in which the front conductive electrode is prepared on the front side of the battery preform and the conductive electrode contact area is exposed on the back side of the battery preform. The front conductive structure and the back conductive structure are used as the two poles to apply voltage, and the battery structure to be processed is processed using laser-enhanced contact optimization technology; Prepare a back conductive electrode.

2. The battery preparation method according to claim 1, characterized in that, The battery preform is a TOPCon battery preform; The preparation of the back conductive electrode includes: Using an electroplating process, the back conductive electrode is formed in the conductive electrode contact area on the back side of the battery structure to be treated, which has been treated with laser-enhanced contact optimization technology.

3. The battery preparation method according to claim 2, characterized in that, After processing the battery structure to be processed using laser-enhanced contact optimization technology, and before forming the back conductive electrode in the conductive electrode contact area on the back side of the battery structure to be processed using an electroplating process, the process further includes: The battery structure to be treated, which has been treated with laser-enhanced contact optimization technology, is subjected to electroplating pretreatment to remove surface impurities and increase the surface roughness of the battery structure to be treated.

4. The battery preparation method according to claim 1, characterized in that, The battery preform is a TOPCon battery preform; A front conductive electrode is fabricated on the front side of the battery preform, including: A front conductive electrode is prepared on the front side of the battery preform using a screen printing process.

5. The battery preparation method according to claim 1, characterized in that, The conductive electrode contact area on the back of the battery structure to be treated is connected to the back conductive structure by using negative pressure adsorption.

6. The battery preparation method according to claim 1, characterized in that, The back side of the battery preform is subjected to a film-opening process to expose the conductive electrode contact area on the back side of the battery preform, including: Laser-assisted delamination is used to delaminate the back of the battery preform, specifically the area corresponding to the grid lines and the area where electroplating clips are located, to expose the conductive electrode contact area on the back of the battery preform.

7. The battery manufacturing method according to any one of claims 1 to 6, characterized in that, The back conductive structure is a flexible conductive layer.

8. The battery preparation method according to claim 7, characterized in that, The front conductive structure is a metal probe.

9. A battery, characterized in that, include: The substrate, passivation functional layers on both sides of the substrate, and front conductive electrodes and back conductive electrodes disposed on both sides aligned with the substrate. The back conductive electrode is prepared by connecting the conductive electrode contact area on the back of the battery structure to be processed to the back conductive structure, connecting the front conductive electrode to the front conductive structure, using the front conductive structure and the back conductive structure as the two poles for applying voltage, and processing the battery structure to be processed using laser-enhanced contact optimization technology. The battery structure to be processed consists of a front conductive electrode fabricated on the front side of the battery preform and a film-opening process performed on the back side of the battery preform to expose the contact area of ​​the conductive electrode; the battery preform includes a substrate and the passivation functional layer.

10. The battery according to claim 9, characterized in that, The back conductive structure is a flexible conductive layer; The flexible conductive layer has through holes to allow negative pressure adsorption to connect the conductive electrode contact area on the back of the battery structure to be processed to the flexible conductive layer.

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