Laser cutting method for flexible battery module

Abstract

The invention relates to the technical field of solar cells, in particular to a laser cutting method for a flexible cell module, which comprises the following steps of: bonding glass and a cell piece together through an adhesive layer; cutting the glass by using a first laser, and synchronously cutting the battery piece by using a second laser; a laser beam emitted by the first laser device and a laser beam emitted by the second laser device are configured to be coaxially focused, so that a first cutting path formed by cutting the glass by the first laser device is aligned with a second cutting path formed by cutting the battery piece by the second laser device; the laser emitted by the first laser forms a plurality of first laser cutting points distributed at intervals on the glass, and the laser emitted by the second laser forms a plurality of second laser cutting points distributed continuously on the battery piece. According to the method, the cutting lines of the glass and the battery piece can be accurately aligned, the subsequent piece cracking and expanding operation is facilitated, the better piece cracking effect is achieved, the production efficiency and the product yield are greatly improved, and the process is simple and easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a laser cutting method for a flexible battery module. Background Art

[0002] With the continuous development of electronic technology, the demand for flexible batteries is increasing.

[0003] The flexible battery cutting method provided by the related technology includes: performing laser pre-cutting on the battery cell and the glass respectively, and gluing the pre-cut battery cell and the glass together by glue to form a stacked structure of glass, glue and battery cell; wherein, before the glue between the glass and the battery cell is cured, it is necessary to adjust the position of the battery cell and the glass so that the pre-cutting line between the battery cell and the glass overlaps, and then perform the curing bonding and the post-bonding splitting and expansion processes.

[0004] However, the flexible battery cutting method provided by the related art is difficult to align the pre-cutting lines of the battery cell and the glass, and deviations are very likely to occur, which in turn easily leads to problems of poor fragmentation in the subsequent fragmentation and expansion of the product. Summary of the invention

[0005] The purpose of the present invention is to provide a laser cutting method for a flexible battery module, which can accurately align the cutting lines of the glass and the battery cell, facilitate subsequent splitting and expanding operations to achieve better splitting effects, greatly improve production efficiency and product yield, and the process is simple and easy to operate.

[0006] The embodiments of the present invention can be implemented as follows: The present invention provides a laser cutting method for a flexible battery module, comprising: Apply glue between the glass and the battery cell and solidify it to form a glue layer for bonding the glass and the battery cell together; the glass has a first surface facing the glue layer and a second surface facing away from the glue layer, and the battery cell has a third surface facing the glue layer and a fourth surface facing away from the glue layer; The glass is cut from the side of the glass facing away from the cell using a first laser, and the cell is cut from the side of the glass facing away from the cell using a second laser simultaneously; wherein: The laser beam emitted by the first laser and the laser beam emitted by the second laser are configured to be coaxially focused so that a first cutting path formed by the first laser on the glass is aligned with a second cutting path formed by the second laser on the battery cell. The laser light emitted by the first laser forms a plurality of first laser cutting points distributed at intervals on the glass, and the laser light emitted by the second laser forms a plurality of second laser cutting points distributed continuously on the battery cell.

[0007] In an optional embodiment, the first laser is a long focal depth picosecond pulse laser, the focal depth range of the laser beam emitted by the first laser is 0.1mm-2mm, and the focus of the laser beam emitted by the first laser is focused between the first surface and the second surface, and is located at 1 / 2~3 / 4 of the distance from the second surface to the first surface.

[0008] In an optional embodiment, the laser power emitted by the first laser is greater than or equal to 50W, the laser wavelength is 532nm, the pulse width is less than 15PS, the single pulse energy is greater than 200uj, the repetition frequency of the laser pulse is 20kHz to 1MHz, and the cutting speed is 1mm / s-3000mm / s; The distance between two adjacent first laser cutting points is 3 μm-10 μm; The first laser cutting point is in the shape of a long strip, and the height of the first laser cutting point is 1 / 3-3 / 4 of the thickness of the glass.

[0009] In an optional embodiment, the second laser is a long focal depth nanosecond laser, the focal depth range of the laser beam emitted by the second laser is 0.01mm-0.2mm, and the focus of the laser beam emitted by the second laser is focused between the third surface and the fourth surface, and is located at 1 / 5~2 / 5 of the distance from the third surface to the fourth surface.

[0010] In an optional embodiment, the laser power emitted by the second laser is 18W-30W, the laser wavelength is 532nm, the pulse width is 10 nanoseconds-200 nanoseconds, the repetition frequency of the laser pulse is 20kHz-1MHz, and the laser cutting speed is 1mm / s-3000mm / s; The depth of the second laser cutting point is 35%-55% of the thickness of the battery cell, with a central value of 45%.

[0011] In an optional embodiment, the speed at which the first laser cuts the glass is the same as the speed at which the second laser cuts the cell.

[0012] In an optional embodiment, the thickness of the glue layer is 25 μm-75 μm.

[0013] In an optional embodiment, the curing is thermal curing, the curing temperature is 50° C.-150° C., the curing time is 10 min-240 min, and the bonding force of the adhesive layer is ≥30N.

[0014] In an optional embodiment, a first cutting positioning point is arranged on a side of the glass facing away from the first laser.

[0015] In an optional embodiment, a second cutting positioning point is provided on a side of the battery sheet facing away from the second laser.

[0016] The beneficial effects of the laser cutting method of the flexible battery module of the embodiment of the present invention include: the laser cutting method of the flexible battery module provided by the embodiment of the present invention first bonds the glass and the battery cell, and then performs coaxial laser cutting on the glass and the battery cell, so as to ensure that the laser cutting lines on the glass and the battery cell are aligned, that is, to ensure that the cutting lines of the glass and the cutting lines of the battery cell are accurately aligned; in the specific cutting implementation method, by "the laser emitted by the first laser forms a plurality of first laser cutting points distributed at intervals on the glass, and the laser emitted by the second laser forms a plurality of second laser cutting points distributed continuously on the battery cell", the consistency of the cutting paths of the two can be effectively guaranteed, which is beneficial to the subsequent splitting and expanding operations to achieve better splitting effects and greatly improve production efficiency and product yield; moreover, the glass and the battery cell are first bonded and then cut, and the process is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of a flexible battery module after cutting in an embodiment of the present invention.

[0019] Icon: 100 - glass; 101 - first surface; 102 - second surface; 110 - first laser cutting point; 200 - adhesive layer; 300 - battery cell; 301 - third surface; 302 - fourth surface; 310 - second laser cutting point. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] 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, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0024] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0025] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0026] Please refer to Figure 1 The present disclosure provides a laser cutting method for a flexible battery module, comprising: applying glue between a glass 100 and a battery cell 300, and curing the glue to form a glue layer 200 for bonding the glass 100 and the battery cell 300 together; the glass 100 has a first surface 101 facing the glue layer 200 and a second surface 102 facing away from the glue layer 200, and the battery cell 300 has a third surface 301 facing the glue layer 200 and a fourth surface 302 facing away from the glue layer 200; using a first laser to cut the glass 100 from a side of the glass 100 facing away from the battery cell 300, and synchronously using a second laser to cut the battery cell 300 from a side of the glass 100 facing away from the battery cell 300; wherein the laser beam emitted by the first laser and the laser beam emitted by the second laser are configured to be coaxially focused so that a first cutting path formed by the first laser cutting on the glass 100 is aligned with a second cutting path formed by the second laser cutting on the battery cell 300.

[0027] Glass 100 is thicker than cell 300 because of its thickness of 0.2-1mm, and because it is transparent and easy for laser to penetrate. In order to maintain the consistency of the cutting paths of glass 100 and cell 300, the multiple first laser cutting points 110 formed by cutting on glass 100 are distributed at intervals, while the multiple second laser cutting points 310 formed by cutting on cell 300 are distributed continuously. Moreover, cell 300 is a silicon wafer, and cracks may occur in multiple directions, which has a certain uncertainty, and the multiple second laser cutting points 310 on cell 300 are also required to be continuous.

[0028] By first bonding the glass 100 and the battery cell 300 and then coaxially laser cutting the glass 100 and the battery cell 300, it is possible to ensure that the laser cutting lines on the glass 100 and the battery cell 300 are aligned, that is, to ensure that the cutting lines of the glass 100 and the cutting lines of the battery cell 300 are accurately aligned; in terms of the specific cutting implementation method, by "the laser emitted by the first laser forms a plurality of first laser cutting points 110 distributed at intervals on the glass 100, and the laser emitted by the second laser forms a plurality of second laser cutting points 310 distributed continuously on the battery cell 300", the consistency of the cutting paths of the two can be effectively guaranteed, which is beneficial to the subsequent splitting and expanding operations to achieve a better splitting effect, and greatly improve the production efficiency and product yield; moreover, the glass 100 and the battery cell 300 are first bonded and then cut, and the process is simple and easy to operate.

[0029] It should be noted that, since the glass 100 is light-transmitting and the battery cell 300 is not light-transmitting, the laser emitted by the second laser can penetrate the glass 100 to cut the battery cell 300. Therefore, when the first laser and the second laser are used to cut the glass 100 and the battery cell 300, both the first laser and the second laser can emit lasers from the side of the glass 100 away from the adhesive layer 200 for cutting.

[0030] It should also be noted that the laser beam emitted by the first laser and the laser beam emitted by the second laser are configured to be coaxially focused, which means that the lasers emitted by the first laser and the second laser are emitted from the same laser emission head, and the laser beams emitted by the two lasers overlap, so as to ensure that the cutting lines formed by the laser beams emitted by the two lasers on the glass 100 and the battery cell 300 respectively are aligned, that is, to ensure that the cutting position on the glass 100 is aligned with the cutting position on the battery cell 300.

[0031] In order to ensure that the coaxially focused first laser and the second laser can respectively cut the overlapping glass 100 and the battery cell 300, it is necessary to make the focusing position and depth of the laser beam emitted by the first laser and the laser beam emitted by the second laser different, to ensure that the laser beam emitted by the first laser is focused on the glass 100, corresponding to cutting the glass 100, and the laser beam emitted by the second laser is focused on the battery cell 300, corresponding to cutting the battery cell 300.

[0032] In the present disclosure, the first laser is a long-focus deep picosecond pulse laser, and the second laser is a long-focus deep nanosecond laser. The first laser uses picoseconds, and the second laser uses nanoseconds. Different pulses are used to improve the problem of light interference, ensuring the reliability of the lasers emitted by the first laser and the second laser to cut the glass 100 and the battery cell 300 synchronously and coaxially; moreover, the use of picoseconds to cut the glass 100 can achieve cutting inside the thicker glass 100 through higher laser energy and high pulses.

[0033] Optionally, the focal depth of the laser beam emitted by the first laser is in the range of 0.1 mm to 2 mm, for example, 0.1 mm, 0.2 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2 mm, etc., which are not specifically limited herein. By controlling the focal depth of the laser beam emitted by the first laser, a long laser spot is formed inside the glass 100, and then a long cutting spot is formed by cutting.

[0034] Furthermore, the focus of the laser beam emitted by the first laser is focused between the first surface 101 and the second surface 102, and is located at 1 / 2 to 3 / 4 of the direction from the second surface 102 to the first surface 101, that is, 1 / 2 to 3 / 4 downward from the second surface 102. In this way, it can be ensured that the cutting position on the thicker glass 100 can be cut and broken smoothly.

[0035] In order to reliably cut the glass 100, the power of the laser emitted by the first laser needs to be adjusted to be larger; optionally, the laser power emitted by the first laser is greater than or equal to 50W, for example: 50W, 55W, 60W, 70W, 80W, 90W, 100W, etc., which is not specifically limited here.

[0036] The cell 300 has better absorption of laser with a wavelength of 532 nm, which enables better cutting of the cell 300 . The glass 100 can also use a laser with the same wavelength band, that is, the laser wavelength of the first laser is 532 nm.

[0037] In order to ensure that the first laser cutting point 110 formed by cutting on the glass 100 is in the shape of a long strip, the pulse width of the first laser is controlled to be less than 15PS (for example: 14.5PS, 14PS, 13.5PS, 13PS, etc., not specifically limited here), the single pulse energy is greater than 200uj (for example: 201uj, 210uj, 220uj, 250uj, 300uj, etc., not specifically limited here), and the repetition frequency of the laser pulse is 20kHz~1MHz (for example: 20kHz, 0.3MHz, 0.5MHz, 0.7MHz, 1MHz, etc., not specifically limited here).

[0038] In order to ensure that the flexible battery module after cutting can take into account both fragmentation and efficiency, and to improve the problem of complete fragmentation bringing adverse effects on subsequent arrangement, the cutting point on the glass 100 can be made approximately in the middle of the glass 100; specifically, the height of the long strip-shaped first laser cutting point 110 formed by the first laser cutting on the glass 100 is 1 / 3 to 3 / 4 of the thickness of the glass 100, that is, the height of the hole (groove) formed by the first laser laser cutting on the glass 100 in the thickness direction of the glass 100 (that is, in the direction from the second surface 102 to the first surface 101) is 1 / 3 to 3 / 4 of the thickness of the glass 100, for example: 1 / 3, 5 / 12, 1 / 2, 7 / 12, 2 / 3, 3 / 4, etc., which are not specifically limited here.

[0039] The thickness of the battery cell 300 is about 100μm, for example: 90-110μm, etc. When cutting the battery cell 300, the focal depth does not need to be particularly long; optionally, the focal depth range of the laser beam emitted by the second laser is 0.01mm-0.2mm, for example: 0.01mm, 0.03mm, 0.05mm, 0.07mm, 0.1mm, 0.12mm, 0.15mm, 0.17mm, 0.2mm, etc., which is not specifically limited here.

[0040] Furthermore, the focus of the laser beam emitted by the second laser is focused between the third surface 301 and the fourth surface 302, and is located at 1 / 5 to 2 / 5 of the direction from the third surface 301 to the fourth surface 302, that is, 1 / 5 to 2 / 5 downward from the third surface 301. Setting the focus of the laser beam emitted by the second laser relatively shallow can improve the problem of too large a light spot on the battery cell 300 due to too deep a focus, and improve the problem of a large impact on the power loss of the battery cell 300.

[0041] Compared with the glass 100, the battery cell 300 is easier to cut; optionally, the laser power emitted by the second laser is 18W~30W (for example: 18W, 20W, 22W, 24W, 26W, 27W, 30W, etc., not specifically limited here), the laser wavelength is 532nm, the pulse width is 10 nanoseconds-200 nanoseconds (for example: 10 nanoseconds, 20 nanoseconds, 30 nanoseconds, 50 nanoseconds, 70 nanoseconds, 100 nanoseconds, 120 nanoseconds, 150 nanoseconds, 170 nanoseconds, 200 nanoseconds, etc., not specifically limited here), and the repetition frequency of the laser pulse is 20kHz~1MHz (for example: 20kHz, 0.3MHz, 0.5MHz, 0.7MHz, 1MHz, etc., not specifically limited here).

[0042] Furthermore, the spacing between two adjacent first laser cutting points 110 on the glass 100 is 3μm-10μm, for example: 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc. If the gap is too small, the glass 100 is prone to cracking under conditions such as shaking, and a slower cutting speed is required, which is not conducive to improving efficiency; when the gap is too large, it is difficult to crack.

[0043] Furthermore, the speed at which the first laser cuts the glass 100 is the same as the speed at which the second laser cuts the battery cell 300. Specifically, the cutting speed is 1mm / s-3000mm / s, for example: 1mm / s, 10mm / s, 100mm / s, 500mm / s, 1000mm / s, 1500mm / s, 2000mm / s, 2500mm / s, 3000mm / s, etc., which is not specifically limited here.

[0044] It should be noted that the above-mentioned cutting speed may refer to the speed at which holes (or grooves) are formed on the glass 100 (or the battery cell 300) by laser cutting. By controlling the laser cutting speeds of the glass 100 and the battery cell 300 to be the same, it is possible to ensure that the cutting paths formed on the more difficult-to-cut glass 100 and the easier-to-cut battery cell 300 remain consistent and synchronized, that is, it is possible to ensure the alignment accuracy of the multiple spaced first laser cutting points 110 formed by laser cutting on the glass 100 and the multiple continuously distributed second laser cutting points 310 formed by laser cutting on the battery cell 300.

[0045] Optionally, the depth of the second laser cutting point 310 is 35%-55% of the thickness of the battery cell 300, and the center value is 45%, that is, the center of the hole (or groove) formed by cutting is at 45% of the thickness of the battery cell 300, that is, the depth of the hole (or groove) formed by laser cutting on the battery cell 300 by the second laser is 30%-55% of the thickness of the battery cell 300 in the direction from the third surface 301 of the battery cell 300 to the fourth surface 302, for example: 35%, 37%, 40%, 43%, 45%, 47%, 50%, 53%, 55%, etc., which are not specifically limited here. Controlling the depth of the second laser cutting point 310 to not more than half of the thickness of the battery cell 300 can effectively avoid adverse effects on battery performance.

[0046] Optionally, the thickness of the adhesive layer 200 between the glass 100 and the battery cell 300 is 25μm-75μm, for example: 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, etc., which are not specifically limited here. If the thickness of the adhesive layer 200 is greater than 75μm, it is easy to burn the adhesive during laser cutting, and it will cause light loss. If you want to achieve a good cutting effect, you need a higher laser energy, which will cause greater cutting damage to the battery cell 300, resulting in damage to the performance of the battery cell 300; if the thickness of the adhesive layer 200 is less than 25μm, the bonding effect is poor, and it is difficult to stably fix the glass 100 and the battery cell 300.

[0047] Furthermore, the curing is thermal curing, for example, a tunnel furnace or an oven can be used for heating curing; the curing temperature is 50°C-150°C (for example, 50°C, 70°C, 90°C, 110°C, 130°C, 150°C, etc., not specifically limited here), the time is 10min-240min (for example, 10min, 50min, 100min, 120min, 150min, 170min, 200min, 220min, 240min, etc., not specifically limited here), the bonding force of the glue layer 200 is ≥30N (for example, 30N, 32N, 35N, 37N, 40N, etc., not specifically limited here), and the cured glue is relatively hard.

[0048] Optionally, a first cutting positioning point is provided on the side of the glass 100 away from the first laser; and / or a second cutting positioning point is provided on the side of the cell 300 away from the second laser. With such a configuration, cutting can be performed along the first cutting positioning point and / or the second cutting positioning point to form a stable cutting path and ensure the accuracy of the cutting position; on the other hand, setting the cutting positioning point on the opposite side of the cutting side can avoid adverse effects on laser cutting.

[0049] It should be noted that the laser cutting method of the flexible battery module disclosed in the present invention also includes splitting and expanding the sheets after cutting, and the specific operation method is similar to the related technology and will not be repeated here.

[0050] It should also be noted that the first laser and the second laser can also deflect the laser emission path through the galvanometer, thereby ensuring the reliability of laser cutting and ensuring that the coaxial laser paths emitted by the first laser and the second laser are consistent and do not interfere with each other.

[0051] The laser cutting method of the flexible battery module of the present invention will be described in detail below in conjunction with specific embodiments.

[0052] Example 1 Glue is applied between the glass and the battery cell and cured to form a glue layer that bonds the glass and the battery cell together; wherein the curing temperature is 50°C and the time is 240 minutes. The thickness of the glue layer formed after curing is 50 μm and the adhesion of the glue layer is 30N.

[0053] The glass is cut by a first laser, and the battery sheet is cut by a second laser simultaneously, and the first laser and the second laser are coaxially focused.

[0054] The laser power of the first laser is 50W, the laser wavelength is 532nm, the pulse width is 14PS, the single pulse energy is 210uj, and the repetition frequency of the laser pulse is 20kHz; the focal depth of the laser beam emitted by the first laser is 0.1mm, and the focus is on the second surface of the glass pointing to 1 / 2 of the first surface.

[0055] The laser power of the second laser is 30W, the laser wavelength is 532nm, the pulse width is 200 nanoseconds, and the repetition frequency of the laser pulse is 20kHz; the focal depth of the laser beam emitted by the second laser is 0.01mm, and the focus is on the third surface of the battery cell pointing to 1 / 5 of the fourth surface.

[0056] The cutting speed of the glass and the battery cell is 1mm / s; the height of the first laser cutting point formed on the glass is 1 / 3 of the thickness of the glass, and multiple first laser cutting points are distributed in sequence with a spacing of 3μm; the depth of the second laser cutting point formed on the battery cell is 45% of the thickness of the battery cell, and multiple second laser cutting points are distributed continuously.

[0057] Example 2 Glue is applied between the glass and the battery cell and cured to form a glue layer that bonds the glass and the battery cell together; wherein the curing temperature is 150°C and the time is 10 minutes. The thickness of the glue layer formed after curing is 25 μm, and the adhesion of the glue layer is 32N.

[0058] The glass is cut by a first laser, and the battery sheet is cut by a second laser simultaneously, and the first laser and the second laser are coaxially focused.

[0059] The laser power of the first laser is 55W, the laser wavelength is 532nm, the pulse width is 13PS, the single pulse energy is 240uj, and the repetition frequency of the laser pulse is 1MHz; the focal depth of the laser beam emitted by the first laser is 2mm, and the focus is on the second surface of the glass pointing to 3 / 4 of the first surface.

[0060] The laser power of the second laser is 18W, the laser wavelength is 532nm, the pulse width is 10 nanoseconds, and the repetition frequency of the laser pulse is 1MHz; the focal depth of the laser beam emitted by the second laser is 0.2mm, and the focus is on the third surface of the battery cell pointing to 2 / 5 of the fourth surface.

[0061] The cutting speed of the glass and the battery cell is 3000mm / s; the height of the first laser cutting point formed on the glass is 3 / 4 of the thickness of the glass, and multiple first laser cutting points are distributed in sequence with a spacing of 10μm; the depth of the second laser cutting point formed on the battery cell is 55% of the thickness of the battery cell, and multiple second laser cutting points are distributed continuously.

[0062] Example 3 Glue is applied between the glass and the battery cell and cured to form a glue layer that bonds the glass and the battery cell together; wherein the curing temperature is 100°C and the time is 100 minutes. The thickness of the glue layer formed after curing is 75 μm, and the adhesion of the glue layer is 50N.

[0063] The glass is cut by a first laser, and the battery sheet is cut by a second laser simultaneously, and the first laser and the second laser are coaxially focused.

[0064] The laser power of the first laser is 50W, the laser wavelength is 532nm, the pulse width is 14.5PS, the single pulse energy is 220uj, and the repetition frequency of the laser pulse is 0.5MHz; the focal depth of the laser beam emitted by the first laser is 1mm, and the focus is on the second surface of the glass pointing to 5 / 8 of the first surface.

[0065] The laser power of the second laser is 24W, the laser wavelength is 532nm, the pulse width is 100 nanoseconds, and the repetition frequency of the laser pulse is 0.5MHz; the focal depth of the laser beam emitted by the second laser is 0.1mm, and the focus is on the third surface of the battery cell pointing to 3 / 10 of the fourth surface.

[0066] The cutting speed of the glass and the battery cell is 1000mm / s; the height of the first laser cutting point formed on the glass is 7 / 12 of the thickness of the glass, and multiple first laser cutting points are distributed in sequence with a spacing of 5μm; the depth of the second laser cutting point formed on the battery cell is 40% of the thickness of the battery cell, and multiple second laser cutting points are distributed continuously and overlappingly.

[0067] Example 4 The difference between Example 4 and Example 1 is that the thickness of the adhesive layer is different. The thickness of the adhesive layer of Example 4 is 80 μm. The other process parameters refer to Example 1.

[0068] The transmittance of the glue thickness in Example 4 is too high, reaching more than 94%, and the laser cannot effectively cut the glue thickness; when the glue layer is thick, although the laser can ensure effective cutting of the glass and the battery cell, the glue cannot be effectively broken during the crack expansion process of the product in the next step after the laser. A larger crack angle or multiple bending and disassembly are required to ensure the cracking effect, otherwise the products will still be connected together by the glue.

[0069] Example 5 The difference between Example 5 and Example 1 is that the process parameters for curing to form the adhesive layer are different. In Example 5, the curing temperature is 40° C. and the curing time is 300 min. The other process parameters refer to Example 1.

[0070] The curing temperature of Example 5 is relatively low, and the glue needs a longer time to cure.

[0071] Example 6 The difference between Example 6 and Example 1 is that the thickness of the adhesive layer is 80 μm, the curing temperature is 40° C., the curing time is 300 min, and the other process parameters refer to Example 1.

[0072] Although the glue of Example 6 can be cured, the excessive thickness of the glue will affect the subsequent splitting and expanding work.

[0073] Example 7 The difference between Example 7 and Example 1 is that the focal depth of the laser beam emitted by the first laser is 0.01 mm, the focus is on the second surface of the glass pointing to 1 / 5 of the first surface, and other process parameters refer to Example 1.

[0074] The glass of Example 7 is cut too shallowly, and the cracked glass and the battery cell are in an irregular state, including broken edges, missing corners, and even cannot be cracked.

[0075] Example 8 The difference between Example 8 and Example 1 is that the focal depth of the laser beam emitted by the first laser and the focal depth of the laser beam emitted by the second laser are both 0.5 mm, and the other process parameters refer to Example 1.

[0076] The glass of Example 8 is cut too shallowly, and the cracked glass and the battery cell are in an irregular state, including: broken edges, missing corners, and even unable to crack.

[0077] Example 9 The difference between Example 9 and Example 1 is that the single pulse energy of the first laser is 180uj, the first laser cutting point formed by laser cutting is not a long strip but roughly a circle, and the focus of the laser beam emitted by the first laser is focused on the second surface pointing to 1 / 5 of the first surface, and the height of the first laser cutting point is 1 / 5 of the thickness of the glass; other process parameters refer to Example 1.

[0078] Only thinner glass can be processed. For example, when the glass thickness is 0.4mm, it can be cracked normally; but if the glass thickness is 2mm, it is more difficult to crack and it is easy to have broken edges and chipped corners.

[0079] Example 10 The difference between Example 10 and Example 1 is that the single pulse energy of the first laser is 180uj, the first laser cutting point formed by laser cutting is not a long strip but roughly a circle, and the focus of the laser beam emitted by the first laser is focused on the second surface pointing to 4 / 5 of the first surface, and the height of the first laser cutting point is 1 / 5 of the thickness of the glass; other process parameters refer to Example 1.

[0080] Only thinner glass can be processed. For example, if the glass thickness is 0.4mm, it can be cracked normally; but if the glass thickness is 2mm, it is more difficult to crack and it is easy to have broken edges and chipped corners.

[0081] Embodiment 11 The difference between Example 11 and Example 1 is that the focus of the laser beam emitted by the second laser is focused on the third surface of the battery cell and points to 3 / 5 of the fourth surface, the depth of the second laser cutting point is 60% of the battery cell, and other process parameters refer to Example 1.

[0082] Only thinner glass can be processed. For example, if the glass thickness is 0.4mm, it can be normally split, but the laser cutting depth is too high, and the thermal impact of the laser on the battery cell is too large, resulting in excessive battery power loss. If the glass thickness is 2mm, it is difficult to split, and it is easy to collapse the edge and corner, and the laser cutting depth is too high, and the thermal impact of the laser on the battery cell is too large, resulting in excessive battery power loss.

[0083] Example 12 The difference between Example 12 and Example 1 is that the focus of the laser beam emitted by the second laser is focused on the third surface of the battery cell and points to 1 / 10 of the fourth surface, the depth of the second laser cutting point is 10% of the battery cell, and other process parameters refer to Example 1.

[0084] Only thinner glass can be processed. For example, if the glass thickness is 0.4mm, normal cracking can be performed, but the cell is cut too shallow and cannot be cracked according to the rules of the laser line, and the cell cracking is irregular. However, if the glass thickness is 2mm, it is more difficult to crack.

[0085] Embodiment 13 The difference between Example 13 and Example 1 is that the repetition frequency of the laser pulses of the first laser and the second laser are both 10 kHz, and the other process parameters refer to Example 1.

[0086] The laser spot repetition frequency of the cell in Example 13 is small or does not overlap, which makes it impossible to effectively split the cell and causes edge breakage.

[0087] Embodiment 14 The difference between Example 14 and Example 1 is that the repetition frequency of the laser pulses of the first laser and the second laser are both 2 MHz, and the other process parameters refer to Example 1.

[0088] The glass laser spot of Example 14 has a large repetitiveness and is easily broken directly after cutting, and the small battery modules are directly scattered.

[0089] Embodiment 15 The difference between Example 15 and Example 1 is that the laser cutting speeds of glass and cell are different, the cutting speed of glass is 1 mm / s, the cutting speed of cell is 2000 mm / s, and other process parameters refer to Example 1. Since it is a coaxial laser, the corresponding cutting operation cannot be achieved.

[0090] Example 16 The difference between Example 16 and Example 1 is that the spacing between two adjacent first laser cutting points is 2 μm, and other process parameters refer to Example 1.

[0091] The distance between the glass laser cutting points in Example 16 is too small, so the glass is easily broken directly after cutting, and the small battery modules are directly scattered.

[0092] Embodiment 17 The difference between Example 17 and Example 1 is that the spacing between two adjacent first laser cutting points is 12 μm, and other process parameters refer to Example 1.

[0093] The distance between the glass laser cutting points in Example 17 is too large, making it difficult to split the glass after cutting, and prone to edge chipping and breakage.

[0094] Embodiment 18 The difference between Example 18 and Example 1 is that: the thickness of the glue layer is 80μm, the temperature of the glue layer curing is 40℃, and the time is 300min; the single pulse energy of the first laser is 180uj, and the first laser cutting point formed by laser cutting is not a long strip, but roughly a circle, and the focus of the laser beam emitted by the first laser is focused on the second surface pointing to 1 / 5 of the first surface, and the height of the first laser cutting point is 1 / 5 of the thickness of the glass; the focus of the laser beam emitted by the second laser is focused on the third surface of the battery cell pointing to 3 / 5 of the fourth surface, and the depth of the second laser cutting point is 60% of the battery cell; other process parameters refer to Example 1.

[0095] Only thinner glass can be processed. For example, if the glass thickness is 0.4mm, it can be normally split, but the laser cutting depth is too high, and the thermal impact of the laser on the battery cell is too large, resulting in excessive battery power loss. If the glass thickness is 2mm, it is difficult to split, and it is easy to collapse the edge and corner, and the laser cutting depth is too high, and the thermal impact of the laser on the battery cell is too large, resulting in excessive battery power loss.

[0096] Embodiment 19 The difference between Example 19 and Example 1 is that: the thickness of the glue layer is 80μm, the temperature of the glue layer curing is 40℃, and the time is 300min; the single pulse energy of the first laser is 180uj, and the first laser cutting point formed by laser cutting is not a long strip, but roughly a circle, and the focus of the laser beam emitted by the first laser is focused on the second surface pointing to 4 / 5 of the first surface, and the height of the first laser cutting point is 1 / 5 of the thickness of the glass; the focus of the laser beam emitted by the second laser is focused on the third surface of the battery cell pointing to 1 / 10 of the fourth surface, and the depth of the second laser cutting point is 10% of the battery cell; other process parameters refer to Example 1.

[0097] Only thinner glass can be processed. For example, if the glass thickness is 0.4mm, normal cracking can be performed, but the cell is cut too shallow and cannot be cracked according to the rules of the laser line, and the cell cracking is irregular. However, if the glass thickness is 2mm, it is more difficult to crack.

[0098] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the laser beam emitted by the first laser cuts the glass to form multiple continuous first laser cutting points, and the laser beam emitted by the second laser cuts the battery cell to form multiple second laser cutting points that are distributed in sequence at intervals rather than continuously. Please refer to Example 1 for other process parameters.

[0099] The glass cutting points of Comparative Example 1 overlap, and the glass is easy to crack directly after cutting; the laser points of the battery cell are discontinuous, the battery cell cannot be effectively split, and the cracks are irregular.

[0100] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the laser beam emitted by the first laser cuts the glass to form multiple continuous first laser cutting points, and the laser beam emitted by the second laser cuts the battery cell to form multiple continuous second laser cutting points; please refer to Example 1 for other process parameters.

[0101] In comparative example 2, the glass cutting points overlap, and during the film removal process, the small battery modules are scattered and cannot form a whole to the next process; the glass is even prone to cracking directly after cutting.

[0102] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the laser beam emitted by the first laser cuts the glass to form multiple discontinuous first laser cutting points, and the laser beam emitted by the second laser cuts the battery cell to form multiple discontinuous second laser cutting points; please refer to Example 1 for other process parameters.

[0103] The laser spots on the cell of Comparative Example 3 are discontinuous and cannot effectively split the cell, and the cell splits are irregular.

[0104] In summary, the laser cutting method of the flexible battery module of the present invention can accurately align the cutting lines of the glass and the battery cell, which is beneficial to the subsequent splitting and expanding operations to achieve better splitting effects, greatly improve production efficiency and product yield, and the process is simple and easy to operate.

[0105] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A laser cutting method for a flexible battery module, characterized in that: include: Applying glue between the glass and the cell and curing the glue to form a glue layer that bonds the glass and the cell together; The glass has a first surface facing the glue layer and a second surface facing away from the glue layer, and the battery cell has a third surface facing the glue layer and a fourth surface facing away from the glue layer; The glass is cut from a side of the glass away from the cell using a first laser, and the cell is cut from a side of the glass away from the cell using a second laser simultaneously; wherein: The laser beam emitted by the first laser and the laser beam generated by the second laser are configured to be coaxially focused so that a first cutting path formed by the first laser cutting on the glass is aligned with a second cutting path formed by the second laser cutting on the battery cell. The laser light emitted by the first laser forms a plurality of first laser cutting points distributed at intervals on the glass, and the laser light emitted by the second laser forms a plurality of second laser cutting points distributed continuously on the battery cell.

2. The laser cutting method of the flexible battery module according to claim 1, characterized in that: The first laser is a picosecond pulse laser with a long focal depth. The focal depth range of the laser beam emitted by the first laser is 0.1mm-2mm. The focus of the laser beam emitted by the first laser is focused between the first surface and the second surface, and is located at 1 / 2~3 / 4 of the distance from the second surface to the first surface.

3. The laser cutting method of the flexible battery module according to claim 2, characterized in that: The laser power emitted by the first laser is greater than or equal to 50W, the laser wavelength is 532nm, the pulse width is less than 15PS, the single pulse energy is greater than 200uj, the repetition frequency of the laser pulse is 20kHz to 1MHz, and the cutting speed is 1mm / s-3000mm / s; The distance between two adjacent first laser cutting points is 3 μm-10 μm; The first laser cutting point is in the shape of a long strip, and the height of the first laser cutting point is 1 / 3-3 / 4 of the thickness of the glass.

4. The laser cutting method of the flexible battery module according to claim 1, characterized in that: The second laser is a nanosecond laser with a long focal depth. The focal depth range of the laser beam emitted by the second laser is 0.01mm-0.2mm. The focus of the laser beam emitted by the second laser is focused between the third surface and the fourth surface, and is located at 1 / 5~2 / 5 of the distance from the third surface to the fourth surface.

5. The laser cutting method of the flexible battery module according to claim 4, characterized in that: The laser power emitted by the second laser is 18W-30W, the laser wavelength is 532nm, the pulse width is 10 nanoseconds-200 nanoseconds, the repetition frequency of the laser pulse is 20kHz-1MHz, and the laser cutting speed is 1mm / s-3000mm / s; The depth of the second laser cutting point is 35%-55% of the thickness of the battery cell, with a central value of 45%.

6. The laser cutting method of the flexible battery module according to claim 1, characterized in that: The speed at which the first laser cuts the glass is the same as the speed at which the second laser cuts the cell.

7. The laser cutting method of the flexible battery module according to claim 1, characterized in that: The thickness of the adhesive layer is 25 μm-75 μm.

8. The laser cutting method of the flexible battery module according to claim 1, characterized in that: The curing is thermal curing, the curing temperature is 50° C.-150° C., the curing time is 10 min.-240 min. The adhesive force of the adhesive layer is ≥30N.

9. The laser cutting method of the flexible battery module according to claim 1, characterized in that: A first cutting positioning point is arranged on a side of the glass facing away from the first laser.

10. The laser cutting method of the flexible battery module according to claim 1, characterized in that: A second cutting positioning point is arranged on a side of the cell facing away from the second laser.

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