Cutting method and cutting device

Abstract

The invention provides a cutting method and a cutting device, and relates to the technical field of precision cutting machining. The cutting method comprises the steps that a battery piece is installed and fixed, the battery piece is provided with a preset cutting path, and the battery piece has preset bending moments on the two sides of the preset cutting path; laser is used for cutting an induction groove along a preset cutting path of the battery piece; and spraying a cooling medium into the inducing groove. According to the cutting method, the preset bending moment can be applied to the two sides, located on the preset cutting path, of the battery piece to generate the tensile stress, then the cooling medium with the preset pressure is sprayed to the induction groove in a matched mode, the tensile stress is increased when cold and hot stress cracking is generated, and the cracking efficiency of the battery piece is improved; obviously, by using the cutting method provided by the invention, the processing time of a cold and hot stress direct splitting technology after the laser induction groove is applied can be shortened, and the working efficiency is higher.

Description

Technical Field

[0001] The present application relates to the field of precision cutting processing technology, and in particular to a cutting method and a cutting device. Background Art

[0002] At present, solar cells are often cut and split using laser ablation combined with mechanical breaking technology or laser-induced groove and hot and cold stress direct splitting technology. However, there is a problem that cannot be ignored in single or multiple laser ablation treatment methods, namely the formation of a heat-affected zone on the surface of the cell, resulting in a relative depth of the surface cutting damage layer reaching 40-45%. In contrast, laser-induced groove and hot and cold stress direct splitting technology has solved this problem to a certain extent. However, compared with the traditional laser ablation combined with mechanical breaking technology, laser-induced groove and hot and cold stress direct splitting technology requires a longer processing time and has low production efficiency. Summary of the Invention

[0003] In view of this, the purpose of this application is to overcome the shortcomings of the existing technology and provide a cutting method and a cutting device that can shorten the processing time of the direct splitting technology of cold and hot stress after applying laser induced grooves, and improve work efficiency.

[0004] The present invention provides the following technical solutions:

[0005] In a first aspect, an embodiment of the present application provides a cutting method, the cutting method comprising:

[0006] Install and fix the battery sheet, wherein the battery sheet has a preset cutting path and the battery sheet is located on both sides of the preset cutting path with a preset bending moment;

[0007] Cutting the induction groove along the preset cutting path of the battery cell by using a laser;

[0008] A cooling medium is sprayed into the induction tank.

[0009] In one embodiment of the first aspect, the step of mounting and fixing the battery cell, wherein the battery cell has a preset cutting path and the battery cell is positioned on both sides of the preset cutting path with a preset bending moment, includes:

[0010] The battery cell is fixed on the cutting table, and has a preset cutting path. The battery cell is bent in the same direction on both sides of the preset cutting path, so that the battery cell has the preset bending moment on both sides of the preset cutting path.

[0011] In one embodiment of the first aspect, the bending deflection of the battery cell is W, which satisfies: 0.1 mm ≤ W ≤ 0.7 mm.

[0012] In one embodiment of the first aspect, the step of mounting and fixing the battery cell on a cutting table includes:

[0013] The battery cell is mounted and fixed on the cutting table by negative pressure adsorption.

[0014] In one embodiment of the first aspect, the step of cutting the induction groove along a preset cutting path of the cell using a laser includes:

[0015] Cutting a groove in the passivation layer of the cell along the preset cutting path of the cell using a first laser;

[0016] The induced groove is cut into the crystalline silicon layer of the cell along the groove by using a second laser.

[0017] In one embodiment of the first aspect, the spraying of cooling medium into the induction groove includes:

[0018] The cooling medium is sprayed into the induction groove to form flushing points on the surface of the battery cell, and the flushing points are enabled to move along the induction groove.

[0019] In one embodiment of the first aspect, the step of spraying the cooling medium into the induction groove to form flushing points on the surface of the battery cell, and enabling the flushing points to move along the induction groove, includes:

[0020] The cooling medium is sprayed into the induction groove and a flushing point is formed on the surface of the battery cell. The laser forms a light spot on the surface of the battery cell. The flushing point and the light spot are set with a preset distance on the preset cutting path, and the flushing point and the light spot can move synchronously along the induction groove.

[0021] In one embodiment of the first aspect, the spraying of cooling medium into the induction groove includes:

[0022] A liquid cooling medium is sprayed into the induction tank.

[0023] In a second aspect, an embodiment of the present application provides a cutting device, which is applied to the cutting method described in any of the above embodiments, and the cutting device includes:

[0024] A cutting table is used to install and fix the battery cells and to provide the battery cells with a preset bending moment on both sides of the preset cutting path.

[0025] a laser cutting assembly, the laser cutting assembly being used to emit laser light and use the laser light to cut an induction groove along the preset cutting path of the battery cell;

[0026] A cooling spray assembly is used to spray cooling medium into the induction groove.

[0027] In one embodiment of the second aspect, the cutting device further comprises:

[0028] A moving component, wherein the moving component is connected to the laser cutting component and the cooling spray component respectively, and the moving component is capable of driving the laser cutting component and the cooling spray component to move along the preset cutting path; wherein the laser cutting component and the cooling spray component are arranged at intervals along the preset cutting path.

[0029] In one embodiment of the second aspect, the cutting table comprises:

[0030] A support platform, the support platform having a supporting end surface;

[0031] A limiting member is connected to the support platform, and the limiting member can limit the battery cell relative to the support end surface so that the support end surface is at least partially in contact with the battery cell, and the battery cell is located on both sides of the preset cutting path and is bent in the same direction.

[0032] In one embodiment of the second aspect, the limiting member includes:

[0033] A plurality of negative pressure adsorption parts are distributed on the support end surface, and at least part of all the negative pressure adsorption parts can contact and negatively adsorb the battery sheet.

[0034] The embodiments of the present application have the following advantages:

[0035] The cutting method provided in the present application can generate tensile stress by applying a preset bending moment to the battery cell on both sides of the preset cutting path, and then spray a cooling medium with a preset pressure into the induced groove to increase the tensile stress when generating cold and hot stress cracks, thereby improving the cracking efficiency of the battery cell; obviously, by using the cutting method provided in the present application, the processing time of the cold and hot stress direct cracking technology after applying the laser induced groove can be shortened, and the work efficiency is higher.

[0036] In addition, the present application also relates to a cutting device. Since the above-mentioned cutting method has the above-mentioned technical effects, the cutting device including the cutting method should have the same technical effects, which will not be repeated here.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A schematic diagram of a process of a cutting method provided in an embodiment of the present application is shown;

[0040] Figure 2 A schematic diagram of a cutting state of a battery cell provided in an embodiment of the present application is shown;

[0041] Figure 3 A schematic diagram of a bent state of a battery cell provided by an embodiment of the present application is shown;

[0042] Figure 4 A schematic structural diagram of a battery cell provided in an embodiment of the present application is shown.

[0043] Description of main component symbols:

[0044] 100-cell; 110-preset cutting path; 120-crystalline silicon layer; 130-passivation layer; 131-grooving; 121-induction groove; 200-washing point; 300-light spot; 400-clamp. DETAILED DESCRIPTION

[0045] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0046] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. Conversely, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0047] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used in the template description herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0050] Among related technologies, laser-induced grooves followed by direct thermal stress cleavage (non-destructive scribing) is an advanced material processing method, particularly suitable for slicing brittle materials such as semiconductors, glass, and ceramics. This method combines laser technology with the principles of material physics to achieve efficient, precise, and virtually microcrack-free cutting in a non-contact manner. The following describes the basic principles and process of this technology:

[0051] Basic Principles: 1) Laser-Induced Groove Formation: First, a high-energy-density laser beam (such as ultraviolet, green, or infrared laser) is used to form a fine, precise groove on or within the material. The laser is focused on the material, locally heating the material to its melting or boiling point, instantly evaporating or melting it, and forming a groove with controllable depth. This process allows for precise control of the groove's depth and width, ensuring a minimal heat-affected zone and minimizing damage to surrounding materials. 2) Induction of Thermal and Cold Stress: After laser processing, the material surface rapidly cools to form a thin hardened layer, while the interior of the material remains at a higher temperature due to slower heat conduction. This temperature gradient generates thermal stress within the material. When this stress exceeds the material's fracture toughness, a crack forms along the laser-induced groove and rapidly propagates along the laser groove, achieving material separation. 3) Direct Splitting: By precisely controlling the laser processing parameters and the subsequent cooling process, the material is directly split along the induced groove under the action of internal stress, completing the cutting and slicing process.

[0052] This method avoids the edge damage and residual stress associated with traditional laser ablation combined with mechanical breaking techniques, improving cutting quality. Compared to traditional mechanical or diamond tool cutting, laser-induced cleavage produces virtually no microcracks or edge damage, preserving material integrity. It is applicable in the semiconductor industry for the fine-cutting of chips, LED wafers, and solar cells.

[0053] However, compared with the traditional laser ablation combined with mechanical breaking technology, the laser-induced groove and hot and cold stress direct breaking technology requires a longer processing time and has low production efficiency.

[0054] like Figure 1 and Figure 2 As shown, in order to solve the above technical problems, an embodiment of the present application provides a cutting method, which includes the following steps:

[0055] S100. Install and fix the cell 100, the cell 100 having a preset cutting path 110, and the cell 100 located on both sides of the preset cutting path 110 has a preset bending moment;

[0056] In this embodiment, the cell 100 of the present application is an N-type solar cell 100 or a P-type solar cell 100. Of course, the cell 100 may also be an HJT cell 100, a Topcon cell 100, an IBC cell 100, a SiNx cell 100, an AlOx cell 100, a SiOx cell 100, an HBC cell 100, etc., and is not specifically limited here.

[0057] In actual operation, the battery cell 100 is first fixed and installed, for example, the battery cell 100 is fixed to the cutting table to ensure that it does not shift during laser cutting, which can help improve the accuracy of the position of the induction groove 121 cut on the battery cell 100. Of course, other methods can also be used to fix the battery cell 100, such as the following commonly used installation and fixing methods: 1) Backplane pasting: Use a double-sided tape with high viscosity or a special photovoltaic back film to stick the battery cell 100 to the backplane. This method is simple and fast and suitable for mass production, but it is necessary to ensure the stability of the pasting material at different temperatures to maintain the preset bending moment of the battery cell 100. 2) Frame bar fixation: The battery cell 100 is fixed between the glass or transparent plastic front plate and the back plate by conductive glue or adhesive, and then sealed and fixed with frame bars (such as aluminum alloy frames) on all sides. The frame bar can not only fix the battery cell 100, but also provide mechanical protection and waterproof functions. 3) Fixture or Tray Positioning: In automated assembly lines, precision-designed fixtures or trays are used to position and secure the cell 100, ensuring precise alignment along the predetermined cutting path 110. This method is suitable for high-precision production and effectively controls the predetermined bending moment of the cell 100. 4) Hot Melt Adhesive Dot Application: A small amount of hot melt adhesive is applied to specific points on the cell 100, securing the cell 100 without affecting the subsequent cutting process. This method allows for precise control of the location and quantity of adhesive dots, reducing stress on the cell 100. 5) Automatic Laminating Machine: Automated equipment, such as an automatic laminating machine, precisely controls the location and amount of adhesive applied to secure the cell 100 along both sides of the predetermined cutting path 110, while also accounting for bending moment to ensure stability during cutting. 6) Elastic Fixtures: Fixtures with elastic elements, such as spring clips or elastic clamping mechanisms, can secure the cell 100 while allowing for a certain degree of fine-tuning to accommodate the predetermined bending moment and ensure precise alignment along the cutting path. Each of the above installation and fixing methods has its advantages and applicable scenarios. When choosing, it is necessary to comprehensively consider production efficiency, cost, battery cell 100 type, cutting process, and durability and reliability of the final product.

[0058] In addition, it is necessary to apply a force on both sides of the preset cutting path 110 of the installed and fixed battery cell 100 so that the battery cell 100 on both sides of the preset cutting path 110 has a preset bending moment, thereby enabling the battery cell 100 on both sides of the preset cutting path 110 to enable the notch of the induction groove 121 opened on the preset cutting path 110 to have an expansion tendency.

[0059] For example, the upper end of the cutting table has a support end surface, which is higher in the middle and lower at both ends. Obviously, the two sides of the battery cell 100 are fixed to the two sides of the support end surface by a fixing mechanism, and the middle of the battery cell 100 is kept in contact with the middle of the support end surface. In other words, the preset cutting path 110 is located in the middle of the support end surface, thereby causing the two sides of the battery cell 100 to bend downward and the middle to bulge upward. As a result, the battery cell 100 on both sides of the preset cutting path 110 has tensile stress acting on both sides of the induction groove 121, which is conducive to the expansion of the induction groove 121 and accelerates the separation of the portion of the battery cell 100 on both sides of the induction groove 121.

[0060] S200. Using a laser to cut the induction groove 121 along the preset cutting path 110 of the cell 100;

[0061] In this embodiment, a high-energy laser is used to irradiate the surface of the cell 100 along a preset cutting path 110. The thermal expansion at the laser-generated spot 300 generates compressive stress in the thickness direction of the cell 100, and subsequently tensile stress is formed on the surface of the material after laser irradiation. This uses the high-energy laser to form precise cutting marks on the surface or inside the cell 100, thereby forming the induced groove 121. This method can achieve high precision, a low heat-affected zone, and reduced edge damage.

[0062] It should be noted that the induction groove 121 is formed in the crystalline silicon layer 120 , and the depth of the induction groove 121 can be set according to actual conditions.

[0063] For example, taking an N-type solar cell 100 or a P-type solar cell 100 as an example, the passivation layer 130 of the cell 100 must be pre-cut, and then the crystalline silicon layer 120 must be cut to form the induction groove 121 in the crystalline silicon layer 120. In other words, the cutting layer of the cell 100 includes the passivation layer 130 and the crystalline silicon layer 120. In other embodiments, taking an HJT cell 100 as an example, the cutting layer includes a TCO layer, an amorphous silicon layer 120, and a crystalline silicon layer 120; or, taking a Topcon cell as an example, the cutting layer includes a SiNx layer, an amorphous silicon layer 120, and a crystalline silicon layer 120; or, taking a PERC cell 100 as an example, the cutting layer includes a SiNx layer, an AlOx layer, and a crystalline silicon layer 120, and so on. These examples are not listed here one by one; the specific number of cutting layers depends on the type of cell 100.

[0064] S300 . Spraying cooling medium into the induction tank 121 .

[0065] In this embodiment, a cooling medium is sprayed into the induction groove 121 through a nozzle. By adjusting the direction of the nozzle, the cooling medium can be at least partially applied to the induction groove 121, so that the cooling medium entering the induction groove 121 can not only cool the induction groove 121 to produce cold and hot stress cracks, but also squeeze the two sides of the induction groove 121 through the cooling medium to cooperate with the preset bending moment to accelerate the expansion of the induction groove 121, which is conducive to the fracture at the induction groove 121.

[0066] It should be noted that the portion of the cooling medium acting on both sides of the induction groove 121 can act vertically on the battery cell 100, thereby pressing the battery cell 100, which can reduce the probability of displacement of the battery cell 100 during the cutting process.

[0067] For example, the spray medium can closely follow the movement of the laser, which can reduce damage to the silicon crystal layer surface and heat loss during the cutting process, thereby reducing efficiency losses; and can ensure that the cold and hot stress cracking effects generated in the induction groove 121 are basically consistent. Of course, the cooling medium can also be sprayed on the entire induction groove 121 after the induction groove 121 is cut.

[0068] By applying the cutting method provided in the present application, a preset bending moment can be applied to the battery cell 100 on both sides of the preset cutting path 110 to generate tensile stress, and then a cooling medium with a preset pressure is sprayed into the induced groove 121 to increase the tensile stress when generating hot and cold stress cracks, thereby improving the cracking efficiency of the battery cell 100; obviously, by using the cutting method provided in the present application, the processing time of the hot and cold stress direct cracking technology after applying the laser induced groove 121 can be shortened, and the work efficiency is higher.

[0069] like Figure 2 and Figure 3 As shown, in some embodiments, in step S100, the battery cell 100 is installed and fixed, the battery cell 100 has a preset cutting path 110, and the battery cell 100 is positioned on both sides of the preset cutting path 110 with a preset bending moment, including:

[0070] The cell 100 is mounted and fixed on the cutting table. The cell 100 has a preset cutting path 110 , and the cell 100 is bent in the same direction on both sides of the preset cutting path 110 , so that the cell 100 has a preset bending moment on both sides of the preset cutting path 110 .

[0071] For example, Figure 2As shown, the cutting table is configured as an arc-shaped plate, and the preset bending moment is formed by three-point bending. That is, the two ends of the battery cell 100 are fixed to the cutting table, and the middle portion of the battery cell 100 is lifted up by the cutting table to form a convex state, thereby forming a three-point bend. The side of the battery cell 100 facing the cutting table is the inner side, and the side of the battery cell 100 away from the cutting table is the outer side. The preset cutting path 110 is located outside the middle portion of the battery cell 100.

[0072] It is easy to understand that the bending deflection of the battery cell 100 is δ, the bending moment of the battery cell 100 is M, and the relationship between the bending deflection δ and the bending moment M is expressed as:

[0073] M=Lt 3 Eδ / W 2 ; Wherein, L is the length of the substrate, W is the width of the substrate, and t is the thickness of the substrate.

[0074] From this calculation, we know that the maximum bending stress corresponding to the top surface of the substrate is 6Etδ / W 2 .

[0075] Obviously, it is difficult to achieve a high cutting speed and good surface quality when only using laser to separate the cell 100. Therefore, in this embodiment, a preset bending moment is added to the cell 100, thereby increasing the tensile stress along the separation path to improve the surface quality and cutting speed.

[0076] In some embodiments, the cutting table is configured to be able to adjust the curvature of the battery cell 100, that is, the bending deflection of the battery cell 100 is adjustable, thereby enabling the cutting table provided by this embodiment to be applicable to various types of battery cells 100, such as battery cells 100 with higher and different bending moduli. In actual operation, the bending deflection needs to be set according to the bending modulus of the battery cell 100. In other words, battery cells 100 with a larger bending modulus are suitable for having the bending deflection of the battery cell 100 set to a smaller value through the cutting table; battery cells 100 with a smaller bending modulus are suitable for having the bending deflection of the battery cell 100 set to a larger value through the cutting table. This is not specifically limited here and is selected based on the material properties of the actual battery cell 100.

[0077] For example, the cutting table includes a base and a support panel. The middle portion of the support panel abuts the support portion of the base, and the two sides of the support panel are threadedly connected to the base via bolts. The height of the two sides of the support panel can be adjusted by controlling the screwing depth of the bolts, that is, the bending deflection of the support panel can be adjusted. After the bending deflection of the support panel is adjusted, a fixing mechanism is used to fix the two ends of the battery cell 100 to the support panel, and the battery cell 100 and the support panel are kept in contact, thereby making the bending deflection of the battery cell 100 and the support panel consistent. Optionally, the fixing mechanism is a clamp 400; of course, in other embodiments, it can also be a double-sided adhesive tape, etc., which is not specifically limited here.

[0078] In some embodiments, in step S100 , the bending deflection of the battery cell 100 is W, which satisfies: 0.1 mm ≤ W ≤ 0.7 mm.

[0079] In this embodiment, the battery cell 100 is bent so that both sides of the battery cell 100 have a preset bending moment; that is, the battery cell 100 has a bending moment deflection, and accordingly, a preset deflection is set. It is easy to understand that when installing and fixing the battery cell 100, the battery cell 100 needs to be bent until its bending deflection meets the bending deflection requirement.

[0080] For example, the bending deflection of the battery cell 100 is 0.1 mm; of course, in other embodiments, the bending deflection of the battery cell 100 may also be 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, etc., which is not specifically limited here.

[0081] It should be noted that the higher the laser power and bending deflection, the faster the maximum cutting speed of the cell 100, and the corresponding improvement in cutting efficiency. However, as the laser power or bending deflection increases, the cross-sectional quality of the cell 100 is affected. Excessive laser power leads to excessively high temperatures, which can damage the surface of the cell 100; or if the bending deflection is too high, the corresponding increase in bending stress may cause mechanical damage or cell breakage. In other words, the cutting speed affects the cutting efficiency and effect, and different speeds result in different heating conditions for the cell 100. Therefore, the bending deflection of the cell 100 should not be set too large or too small. If the bending deflection of the cell 100 is too small, the improvement in cutting efficiency will be minimal; if the bending deflection of the cell 100 is too large, it will damage the cell 100 and affect the cross-sectional quality of the cell 100.

[0082] In some embodiments, in step S100 , the battery cell 100 is mounted and fixed on the cutting table, including: mounting and fixing the battery cell 100 on the cutting table by negative pressure adsorption.

[0083] Obviously, using negative pressure to fix the cell 100 facilitates quick loading and unloading. When the side of the cutting table that contacts the cell 100 is configured as a curved surface, negative pressure can be used to hold the cell 100 in place to maintain the fit between the cell 100 and the cutting table, facilitating precise control of the cell 100's bending deflection.

[0084] In addition, fixing the battery cell 100 by negative pressure adsorption can form a negative pressure zone around the battery cell 100, thereby adsorbing and collecting dust generated by cutting the battery cell 100, thereby reducing pollution to the production environment.

[0085] For example, multiple negative pressure suction ports are distributed at one end of the cutting table contacting the battery cell 100 , and the distribution area of ​​the multiple negative pressure suction ports is larger than the area of ​​the battery cell 100 , thereby forming a negative pressure area around the battery cell 100 .

[0086] It should be noted that when the cooling medium is a liquid cooling medium, such as liquid water, the sprayed cooling water can be absorbed and discharged into the circulating water supply system using negative pressure adsorption, thereby achieving recycling of the cooling water. For example, the circulating water supply system includes a water pump and a water tank, and the water outlet of the water tank is connected to the nozzle through the water pump, thereby spraying cooling water into the induction tank 121.

[0087] Optionally, the negative pressure suction port is connected to the inlet of the negative pressure pump, and the outlet of the negative pressure pump is connected to the water inlet of the water tank, so that the sprayed cooling water can be collected.

[0088] like Figure 2 and Figure 4 As shown, in some embodiments, in step S200, a laser is used to cut an induced groove 121 along a preset cutting path 110 of the battery cell 100, including: using a first laser to cut a groove 131 in the passivation layer 130 of the battery cell 100 along the preset cutting path 110 of the battery cell 100; using a second laser to cut the induced groove 121 in the crystalline silicon layer 120 of the battery cell 100 along the groove 131.

[0089] For example, the wavelength range of the first laser is 250-1050 nm, and the laser pulse width of the first laser can be femtoseconds, picoseconds or nanoseconds; the wavelength range of the second laser is 250-1050 nm, and the laser pulse width of the second laser can be picoseconds, nanoseconds, quasi-continuous or continuous.

[0090] When the induced groove 121 is cut by the hot and cold stress splitting method after laser processing, the width of the induced groove 121 should be smaller than the width of the groove 131. Specifically, the first laser is used to ablate the passivation layer 130 of the battery cell 100 to form the groove 131. The depth of the groove 131 is 60-75nm, and the width of the groove 131 is 30-100μm; the second laser is used to scribing so that the cutting width of the head and tail cutting grooves is 30-50μm, and the length of the head and tail induced grooves 121 is 1-3mm. Then, the laser is used to scan from front to back along the direction of the head and tail cutting grooves to cut the induced groove 121. According to the above method, the energy density of the first laser is 0.05-0.4j / cm 2 , and the energy density of the second laser is 70-250j / cm 2 , perform a scanning and marking cutting.

[0091] Optionally, the first laser removes the surface passivation layer 130 while minimizing damage to the substrate by means of galvanometer scanning or focusing mirror cutting. Immediately thereafter, the second laser cuts the crystalline silicon layer 120 (i.e., silicon substrate) in the groove 131. When the second laser is scribing, it can be a single scribing and cutting, or it can be multiple reciprocating scribing and cutting. The position of the second laser scribing is in the middle of the line width of the groove 131. Similarly, during laser thermal cracking, the position of the induced groove 121 and the thermal stress laser is also in the middle of the line width of the groove 131. A cold and hot stress cracking method is adopted after laser grooving 131.

[0092] For example, the Topcon cell 100 is cut. First, a laser is used to emit a first laser to ablate the passivation layer 130 on the surface of the Topcon cell 100, with an ablation depth of 60-80nm and a width of 30-90μm. Among them, the above-mentioned depth is the thickness of the passivation layer 130, and the above-mentioned ablation depth is the thickness of the current Topcon passivation layer 130. When the thickness of the passivation layer 130 changes, the ablation depth can be changed accordingly. Optionally, the laser that emits the first laser is an ultraviolet picosecond laser with the following parameter specifications: 12ps, energy density of 0.1-0.4j / cm 2 , or any intermediate range therein, can be selected as 0.2j / cm 2 .

[0093] In addition, a second laser is emitted using a green or infrared laser to perform laser scribing and cutting. Specifically, the crystalline silicon layer 120 is subjected to multiple scanning scribing and cutting, wherein the cutting depth is 40-50% of the total thickness of the silicon substrate, and the cutting width is smaller than the aforementioned ablation width, and the cutting width is 30-90 μm. Then, a non-destructive cutting method is used to cut the silicon substrate using an induction laser, respectively, to cut the first and last induction grooves 121 on the silicon substrate, wherein the cutting width of the first and last induction grooves 121 is 25-50 μm and the cutting length is 1-3 mm. Then, a splitting laser is used to scan from front to back along the direction of the first and last cut grooves to complete the splitting.

[0094] For example, the energy density of the split laser is 70-250 j / cm 2 , or any intermediate range therein. Optionally, the energy density of the split laser is 150 j / cm 2 .The power density of the split laser is 1W / cm 2 -5W / cm 2 , or any intermediate range therein.

[0095] It should be noted that for high-efficiency solar cells 100, including HJT cells 100, IBC cells 100, HBC cells 100, Topcon cells 100 and other types, the passivation layer 130 and the crystalline silicon body need to be processed during the cutting process. The usual cutting method is to use a single laser for multiple scanning cuts, but by adopting a two-step cutting scheme and adjusting the laser parameters according to the characteristics of the passivation layer 130, the damage and heat loss caused to the surface of the crystalline silicon body during the cutting process can be reduced to a certain extent, thereby reducing efficiency loss. For other types of solar cells 100, such as PERC cells 100, the degree of efficiency damage can also be reduced by removing the AlOx / SiNx passivation layer 130 on the back by ablation.

[0096] That is to say, compared with the single laser cutting method widely used in the industry at present, this application adjusts the appropriate laser wavelength, pulse width, laser energy and other process parameters according to the characteristics of different stacked passivation layers 130, so as to minimize the damage of the laser to each passivation layer 130, thereby reducing the damage to the electrical properties of the sample caused by the overall laser cutting process.

[0097] like Figure 2 As shown, in some embodiments, in step S300 , spraying the cooling medium into the induction groove 121 includes spraying the cooling medium into the induction groove 121 and forming a flushing point 200 on the surface of the battery cell 100 , and enabling the flushing point 200 to move along the induction groove 121 .

[0098] Laser is used to locally and rapidly heat the cell 100 material, and the accompanying cooling medium immediately thereafter generates an uneven temperature field, which is conducive to cell splitting.

[0099] like Figure 2 As shown, in some embodiments, in step S300, a cooling medium is sprayed into the induction groove 121 to form a flushing point 200 on the surface of the battery cell 100, and the flushing point 200 is enabled to move along the induction groove 121, including:

[0100] A cooling medium is sprayed into the induction groove 121 and a scouring point 200 is formed on the surface of the battery cell 100. The laser forms a light spot 300 on the surface of the battery cell 100. The scouring point 200 and the light spot 300 are set at a preset distance on the preset cutting path 110, and the scouring point 200 and the light spot 300 can move synchronously along the induction groove 121.

[0101] For example, a cooling device that sprays cooling medium and a laser that emits laser light move synchronously, and the moving speeds of the two must be kept consistent. The laser can be used to quickly heat and cool the material locally, generating cooling stress, which is conducive to accelerating the splitting and improving the cutting efficiency.

[0102] In some embodiments, in step S300 , spraying the cooling medium into the induction tank 121 includes: spraying the liquid cooling medium into the induction tank 121 .

[0103] For example, the cooling medium is cooling water, the cooling water pressure is 0.2-0.5 MPa, the moving speed of the flushing point 200 and the light spot 300 is 50-300 mm / s, and the cooling water temperature is 5-25° C. In addition, the cooling water can absorb dust and facilitate subsequent recycling.

[0104] An embodiment of the present application also provides a cutting device, which is applied to the cutting method described in any of the above embodiments. The cutting device includes a cutting table, a laser cutting assembly and a cooling spray assembly. The cutting table is used to install and fix the battery cell 100, and to make the battery cell 100 have a preset bending moment on both sides of the preset cutting path 110; the laser cutting assembly is used to emit laser and use laser to cut an induction groove 121 on the preset cutting path 110 of the battery cell 100; the cooling spray assembly is used to spray cooling medium into the induction groove 121.

[0105] Exemplarily, the laser cutting component is a laser, such as a CO2 laser, a fiber laser, a Nd:YAG laser, a disk laser, and the like.

[0106] For example, the cutting table can be shaped to bend the cell 100 mounted thereon. For example, the cutting table can have a support end surface configured as an arc with a convex center. By attaching the cell 100 to the support end surface, the cell 100 can be bent. Alternatively, by fixing the ends of the cell 100 so that they bend downward, the cell 100 can be bent.

[0107] Exemplarily, the cooling spray assembly includes a nozzle, which is directed toward the induction groove 121 , and sprays the cooling medium from the nozzle, thereby enabling the cooling medium to act on the induction groove 121 .

[0108] Since the above-mentioned cutting method has the above-mentioned technical effects, the cutting device including the cutting method should have the same technical effects, which will not be repeated here.

[0109] In some embodiments, the cutting device also includes a moving component, which is respectively connected to the laser cutting component and the cooling spray component, and the moving component is capable of driving the laser cutting component and the cooling spray component to move along the preset cutting path 110; wherein, the laser cutting component and the cooling spray component are arranged at intervals along the preset cutting path 110.

[0110] The laser optical path design utilizes a linear optical path, with the two lasers emitting the primary and secondary lasers, respectively, arranged in a tandem and positioned above the same workstation, making the laser path more compact. This combination of technical features significantly improves the precision and controllability of the cutting process, contributing to optimized solar cell production processes and enhanced production efficiency and product quality.

[0111] Exemplarily, the laser cutting assembly includes a first laser cutting assembly and a second laser cutting assembly, the first laser cutting assembly is used to emit a first laser, and the second laser cutting assembly is used to emit a second laser. The layout of the first laser cutting assembly and the second laser cutting assembly adopts a linear optical path, and the cutting table is provided with at least one workstation. The first laser cutting assembly and the second laser cutting assembly are arranged one after the other along a preset cutting path 110 and are located above the same workstation for processing the battery cell 100.

[0112] The advantage of a linear layout lies in a more compact optical path. The first laser is used to ablate the passivation layer 130, removing the surface passivation film without damage and forming the groove 131. Subsequently, the second laser cuts the crystalline silicon layer 120 or substrate material using laser scribing technology. The first and second laser cutting assemblies are simultaneously located above the same workstation, completing the first and second steps at the same station, resulting in higher cutting efficiency.

[0113] It should be noted that, by connecting the moving assembly to the laser cutting assembly and the cooling spray assembly respectively, the moving assembly is used to drive the laser cutting assembly and the cooling spray assembly to move synchronously along the preset cutting path 110 .

[0114] Exemplarily, the moving component is a linear moving module, such as a synchronous belt type linear module, a ball screw type linear module, a linear motor type linear module, etc., which is not specifically limited here.

[0115] In some embodiments, the cutting table includes a support table and a limit member, the support table has a support end surface; the limit member is connected to the support table, and the limit member can limit the battery cell 100 relative to the support end surface so that the support end surface is at least partially in contact with the battery cell 100, and the battery cell 100 is located on both sides of the preset cutting path 110 and is bent in the same direction.

[0116] For example, the cutting table includes a base, a support panel, a clamp 400 and an adjusting bolt. The two ends of the support panel are connected to the base through adjusting bolts, and the middle part of the support panel is made to be convex. The depth of the adjusting bolts screwed into the base is adjusted in advance to adjust the bending deflection of the support panel, and the battery cell 100 is fixed on the support panel with the help of the clamp 400, so that the battery cell 100 can naturally present a pre-bent state.

[0117] For example, a protrusion is provided in the middle of the pedestal, the protrusion abuts against the inner side of the middle of the support panel, and the height of the protrusion is higher than its two sides, and the two sides of the support panel are respectively connected to the two sides of the protrusion.

[0118] Optionally, the battery cell 100 is laminated to the curved support panel, that is, the bending deflection of the two is the same, which can not only stably support the battery cell 100 through the bottom plate, but also accurately control the bending deflection of the battery cell 100.

[0119] In some embodiments, the stopper includes:

[0120] A plurality of negative pressure adsorption parts are distributed on the support end surface, and at least part of all the negative pressure adsorption parts can contact and negatively adsorb the battery cell 100 .

[0121] Obviously, the negative pressure adsorption unit can be used alone to adsorb and fix the battery cell 100, or it can be used in conjunction with the clamp 400 to fix the battery cell 100, resulting in a more stable fixation effect. Obviously, using multiple negative pressure adsorption units in combination can improve the fit between the battery cell 100 and the support panel, which is beneficial for controlling the bending accuracy of the battery cell 100.

[0122] Among them, a part of the negative pressure adsorption part is exposed, and a part of the negative pressure adsorption part adsorbs and fixes the battery cell 100, and then the exposed negative pressure adsorption part can be used to adsorb the dust generated by cutting and the cooling medium, thereby realizing the recycling of the cooling medium, especially the liquid cooling medium.

[0123] For example, the negative pressure adsorption portion includes a negative pressure suction cup, which is mounted on the outer side of the support panel. Alternatively, a person skilled in the art can provide a hole in the support panel for mounting the negative pressure suction cup, so that when the battery cell 100 is adsorbed by the negative pressure suction cup, the battery cell 100 is precisely attached to the support panel.

[0124] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not limiting, and thus other examples of the exemplary embodiments may have different values.

[0125] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0126] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that variations and modifications are possible without departing from the scope of the present invention, and such variations and modifications are fully within the scope of protection of the present invention.

Claims

1. A cutting method, characterized in that: The cutting method comprises: Install and fix the battery sheet, wherein the battery sheet has a preset cutting path and the battery sheet is located on both sides of the preset cutting path with a preset bending moment; Cutting the induction groove along the preset cutting path of the battery cell by using a laser; A cooling medium is sprayed into the induction tank.

2. The cutting method according to claim 1, characterized in that: The method of installing and fixing the battery sheet, wherein the battery sheet has a preset cutting path and the battery sheet is positioned on both sides of the preset cutting path with a preset bending moment, includes: The battery cell is fixed on the cutting table, and has a preset cutting path. The battery cell is bent in the same direction on both sides of the preset cutting path, so that the battery cell has the preset bending moment on both sides of the preset cutting path.

3. The cutting method according to claim 2, characterized in that: The bending deflection of the battery cell is W, which satisfies: 0.1 mm ≤ W ≤ 0.7 mm.

4. The cutting method according to claim 2 or 3, characterized in that: The step of installing and fixing the battery cell on the cutting table includes: The battery cell is mounted and fixed on the cutting table by negative pressure adsorption.

5. The cutting method according to claim 1, wherein: The method of cutting the induction groove along the preset cutting path of the cell by using a laser comprises: Cutting a groove in the passivation layer of the cell along the preset cutting path of the cell using a first laser; The induced groove is cut into the crystalline silicon layer of the cell along the groove by using a second laser.

6. The cutting method according to claim 1, characterized in that: The step of spraying the cooling medium into the induction groove comprises: The cooling medium is sprayed into the induction groove to form flushing points on the surface of the battery cell, and the flushing points are enabled to move along the induction groove.

7. The cutting method according to claim 6, characterized in that: The step of spraying the cooling medium into the induction groove to form flushing points on the surface of the battery cell, and enabling the flushing points to move along the induction groove, includes: The cooling medium is sprayed into the induction groove and a flushing point is formed on the surface of the battery cell. The laser forms a light spot on the surface of the battery cell. The flushing point and the light spot are set with a preset distance on the preset cutting path, and the flushing point and the light spot can move synchronously along the induction groove.

8. The cutting method according to claim 6 or 7, characterized in that: The step of spraying the cooling medium into the induction groove comprises: A liquid cooling medium is sprayed into the induction tank.

9. A cutting device, characterized in that: The cutting method according to any one of claims 1 to 8, wherein the cutting device comprises: A cutting table, which is used to install and fix the battery cells and to provide the battery cells with a preset bending moment on both sides of a preset cutting path; a laser cutting assembly, the laser cutting assembly being used to emit laser light and use the laser light to cut an induction groove along the preset cutting path of the battery cell; A cooling spray assembly is used to spray cooling medium into the induction groove.

10. The cutting device according to claim 9, characterized in that The cutting device further comprises: A moving component, wherein the moving component is connected to the laser cutting component and the cooling spray component respectively, and the moving component is capable of driving the laser cutting component and the cooling spray component to move along the preset cutting path; wherein the laser cutting component and the cooling spray component are arranged at intervals along the preset cutting path.

11. The cutting device according to claim 9, characterized in that The cutting table comprises: A support platform, the support platform having a supporting end surface; A limiting member is connected to the support platform, and the limiting member can limit the battery cell relative to the support end surface so that the support end surface is at least partially in contact with the battery cell, and the battery cell is located on both sides of the preset cutting path and is bent in the same direction.

12. The cutting device according to claim 11, characterized in that The limiting member includes: A plurality of negative pressure adsorption parts are distributed on the support end surface, and at least part of all the negative pressure adsorption parts can contact and negatively adsorb the battery sheet.

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