Battery piece laser sintering method and battery piece laser sintering equipment

Abstract

The invention relates to the technical field of photovoltaic battery piece manufacturing, and particularly discloses a battery piece laser sintering method and battery piece laser sintering equipment. The sintering method comprises the following steps that voltage is applied to a battery piece, and the battery piece is conveyed from back to front in the front-back direction; laser is emitted towards the battery piece, and dotted light spots are formed on the plane where the battery piece is located when the laser is emitted; moving the laser to enable the light spot to carry out multiple times of cyclic scanning according to a preset scanning path; the scanning path comprises a first path moving from a first point on the first side to a second point on the second side, a second path moving backwards from the second point to a third point, and a third path moving from the third point to the first point; the first path obliquely extends from back to front or is parallel to the transverse direction, and the third path obliquely extends from back to front. According to the invention, the spot-shaped light spots move according to the preset scanning path, the area scanned by the laser can well cover the battery piece, and the energy applied to the battery piece is moderate.

Description

[0001] This application is based on the Chinese patent application entitled “Battery Cell Laser Sintering Method and Battery Cell Laser Sintering Equipment” with application number 202411566611.2 and application date November 5, 2024, and is filed as a divisional of the Chinese patent application. Technical Field

[0002] The present invention relates to the technical field of photovoltaic cell manufacturing, and in particular to a cell laser sintering method and a cell laser sintering device. Background Art

[0003] The contact resistance between the gate electrode and the silicon wafer of a photovoltaic cell (hereinafter referred to as a cell) has a great influence on the fill factor and conversion efficiency of the cell. The lower the contact resistance, the larger the fill factor and the higher the conversion efficiency. In order to reduce the contact resistance, the LECO process is currently used to make cells, that is, when a reverse voltage is applied to the cell, the cell is irradiated with a laser, and an induced current is generated in the area of ​​the cell irradiated with the laser. When the induced current flows through the area with high resistance on the cell, that is, the junction of the gate electrode and the silicon wafer, a large amount of heat is generated, sintering the gate electrode and the silicon wafer, thereby reducing the contact resistance between the gate electrode and the silicon wafer.

[0004] In an existing technology, when a voltage is applied to a battery cell, a laser with a strip-shaped spot is used to irradiate the battery cell. Although the laser with the strip-shaped spot can scan the entire surface of the battery cell, the irradiated area of ​​the battery cell is large, and the energy applied to the battery cell is large, which can easily burn the battery cell. Summary of the invention

[0005] The object of the present invention is to provide a cell laser sintering method and cell laser sintering equipment which use laser to scan the cell during the cell transmission process and can make the energy applied to the cell by the laser be moderate.

[0006] To achieve the above object, the present invention provides a cell laser sintering method, comprising the following steps:

[0007] Applying voltage to the battery cell and conveying the battery cell from back to front in a front-to-back direction;

[0008] emitting a laser toward the battery cell, wherein when the laser is emitted, a dot-shaped light spot is formed on the plane where the battery cell is located;

[0009] Moving the laser so that the light spot performs multiple cycles of scanning along a preset scanning path;

[0010] Assuming that in a transverse direction perpendicular to the front-rear direction, the two sides of the battery sheet are respectively a first side and a second side, the scanning path includes a first path moving from a first point on the first side to a second point on the second side, a second path moving backwards from the second point to a third point, and a third path moving from the third point to the first point on the first side, and the first point is a starting point and an end point of the scanning path;

[0011] The first path extends obliquely from the rear to the front or is parallel to the lateral direction, and the third path extends obliquely from the rear to the front.

[0012] As a further improvement of the present invention, the first path extends obliquely from back to front, the size of the light spot in the front-to-back direction is H, the distance between the first point and the second point in the front-to-back direction and the distance between the third point and the first point in the front-to-back direction are both equal to 0.5H, and the distance the battery cell moves forward during a scan completed by the light spot is H.

[0013] As a further improvement of the present invention, the first path is parallel to the transverse direction, the size of the light spot in the front-to-back direction is H, the distance between the first point and the second point in the front-to-back direction is 0, the distance between the third point and the first point in the front-to-back direction is H, and the distance the battery cell moves forward during a scan completed by the light spot is H.

[0014] As a further improvement of the present invention, both ends of the first path and both ends of the third path extend beyond the battery cell in a lateral direction.

[0015] As a further improvement of the present invention, the ratio of the length of the first path or the third path to the size H of the light spot in the front-to-back direction is not less than 10.

[0016] As a further improvement of the present invention, the wavelength of the laser is 400nm-1200nm, the power is 10W-300W, and the size H of the light spot in the front-back direction is 0.05mm-10mm.

[0017] As a further improvement of the present invention, the shape of the light spot is square or circular.

[0018] As a further improvement of the present invention, it comprises a laser sintering module, wherein the laser sintering module processes the battery cell by using the battery cell laser sintering method as described in any one of claims 1 to 7.

[0019] As a further improvement of the present invention, the laser sintering module comprises at least two groups of powered roller assemblies arranged in the front-to-back direction, and a laser assembly for emitting laser light between the two groups of powered roller assemblies;

[0020] The power-on roller assembly comprises an upper roller and a lower roller that are arranged opposite to each other in the up-down direction. The upper roller and the lower roller are respectively connected to the positive electrode and the negative electrode of the power source to apply a reverse voltage to the battery cell.

[0021] As a further improvement of the present invention, the upper roller and the lower roller each include a rotating shaft, and a contact ring sleeved on the rotating shaft for contacting the battery sheet, and each of the upper rollers and each of the lower rollers is only provided with one contact ring;

[0022] The rotating shaft comprises a main shaft, an insulating layer sleeved on the main shaft, and a conductive layer sleeved on the insulating layer. The contact ring is sleeved on the conductive layer, and the power source is connected to the contact ring through the conductive layer.

[0023] Beneficial effects:

[0024] The cell laser sintering method and cell laser sintering equipment provided by the present invention apply voltage to the cell during the transportation of the cell, and emit laser toward the cell during the transportation of the cell. The light spot formed by the laser on the plane where the cell is located moves according to a preset scanning path. The area scanned by the laser can cover the cell well, and the energy applied to the cell is moderate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a scanning path on a battery cell provided by an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of a scan path provided by yet another embodiment of the present invention;

[0027] Figure 3 A schematic diagram of a scan path provided by yet another embodiment of the present invention;

[0028] Figure 4 For the spot Figure 1 The schematic diagram of the movement track and the scanned area on the battery cell when the scanning path is cyclically scanned is shown;

[0029] Figure 5 For the spot Figure 3 The schematic diagram of the movement track and the scanned area on the battery cell when the scanning path is cyclically scanned is shown;

[0030] Figure 6 A schematic structural diagram of a laser sintering module provided in one embodiment of the present invention;

[0031] Figure 7 A front view of a partial structure of a laser sintering module provided by an embodiment of the present invention;

[0032] Figure 8 for Figure 7A front view of the upper roller or the lower roller;

[0033] Fig. 9 for Figure 7 A side view of the laser sintering module in FIG.

[0034] Fig.10 for Figure 7 Schematic diagram of the circuit structure of the laser sintering module;

[0035] Fig.11 for Figure 7 A top view of the upper roller and solar cells of the laser sintering module;

[0036] Fig.12 A front view of a partial structure of a laser sintering module provided in yet another embodiment of the present invention;

[0037] Fig.13 A side view of a laser sintering module provided in yet another embodiment of the present invention;

[0038] Fig.14 Fig.13 Schematic diagram of the circuit structure of the laser sintering module;

[0039] Fig.15 for Fig.13 A top view of the upper roller and solar cells of the laser sintering module;

[0040] Fig.16 A schematic diagram of a cell laser sintering device in a transmission state provided by an embodiment of the present invention;

[0041] Fig.17 A schematic diagram of a cell laser sintering device provided by an embodiment of the present invention in a non-transmission state;

[0042] Fig.18 It is a schematic diagram of the connection between the lower roller shaft and the support seat in one embodiment of the present invention;

[0043] Fig.19 It is a schematic diagram of the connection between the lifting assembly, the lifting seat and the upper roller shaft in one embodiment of the present invention;

[0044] Fig. 20 It is a schematic diagram of a lifting seat and an upper roller shaft in one embodiment of the present invention;

[0045] Fig.21 It is a schematic diagram showing that the upper roller of the present invention is in a horizontal state. DETAILED DESCRIPTION

[0046] The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. However, the embodiments do not limit the present invention, and any changes in mechanism, method, or function made by a person skilled in the art according to the embodiments are all within the protection scope of the present invention.

[0047] The terms used herein, such as "upper", "lower", "left", "right", "front", "back", etc., which indicate relative spatial positions, are used for the purpose of convenience to describe the relationship between one feature and another feature as shown in the accompanying drawings. It is understood that, depending on the placement of the product, the terms of relative spatial positions may be intended to include different orientations other than those shown in the drawings, and should not be construed as limitations on the claims. In addition, the descriptor "horizontal" used herein is not completely equivalent to being perpendicular to the direction of gravity, and a certain angle of inclination is allowed.

[0048] like Figure 1-5 As shown, the present invention provides a cell laser sintering method, the method comprising the following steps:

[0049] Applying voltage to the battery cell 600 and conveying the battery cell 600 from back to front in the front-back direction, Figure 1-5 The arrow on the right shows the anterior-posterior direction;

[0050] The laser is emitted toward the battery cell 600. When the laser is emitted, a dot-shaped light spot is formed on the plane where the battery cell 600 is located. When the light spot is located on the battery cell 600, it will irradiate a certain area on the battery cell 600. For example, when the laser irradiates the battery cell 600 from top to bottom, it will irradiate a certain area on the front of the battery cell 600.

[0051] The laser is moved so that the light spot performs multiple cycles of scanning along a preset scanning path.

[0052] The voltage is applied to the cell 600, specifically, a reverse voltage is applied to the front and back sides of the cell 600, and the voltage value is preferably 10V-30V. When the reverse voltage is applied, the area on the cell 600 irradiated by the laser will generate an induced current, and when the induced current flows through the area on the cell 600 where the resistance is relatively high, that is, the junction between the gate electrode and the silicon wafer, a large amount of heat will be generated, and the gate electrode and the silicon wafer will be sintered, thereby reducing the contact resistance between the gate electrode and the silicon wafer, so that the conversion efficiency of the cell 600 can be improved.

[0053] The wavelength of the laser is preferably in the range of 400nm-1200nm, and the power is preferably in the range of 10W-300W. The light spot can be in the shape of square, circle, etc., and its size in the front-back direction is H, and the range of H is preferably 0.05mm-10mm.

[0054] The laser can be a continuous laser or a pulsed laser, which is emitted by a continuous laser or a pulsed laser respectively. In this embodiment, a pulsed laser is preferably used, and the frequency of the laser emitted by the pulsed laser is 50KHZ-4000KHZ. The pulsed laser has moderate energy applied to the battery cell 600.

[0055] In the transverse direction perpendicular to the front-rear direction, the two sides of the battery cell 600 are respectively the first side and the second side. Figure 1 The middle is the left and right direction, Figure 1 In the embodiment, the left side of the battery cell 600 is the first side, and the right side is the second side. In other embodiments, the right side of the battery cell 600 may be the first side, and the left side may be the second side.

[0056] The scanning path includes a first point O from the first side 1 Move to the second point O on the second side 2 The first path S1, from the second point O 2 Move back to the third point O 3 The second path S2 and the path from the third point O 3 Move to the third path S3 of the first side. The scanning path is a closed loop path. 1 is the starting point and the end point of the scanning path, that is, after the light spot moves from the second side to the first side along the third path S3, it will return to the first point O 1 .

[0057] The first path S1 extends obliquely from the back to the front or is parallel to the transverse direction, and the third path S3 extends obliquely from the back to the front.

[0058] When the battery cell 600 is transported from the back to the front, the light spot is formed along the first path S1 from the first point O on the first side. 1 Move to the second point O on the second side 2 , will scan part of the cell 600 and radiate the scanned area. After passing through the first path S1, the light spot first moves from front to back along the second path S2, and then moves from back to front along the third path S3. In this way, it is possible to avoid the overlap of the area on the cell 600 scanned by the light spot along the third path S3 and the area on the cell 600 previously scanned by the light spot along the first path S1. The light spot can scan as much area on the cell 600 as possible, and the scanning path can eventually return to the first point O. 1 .

[0059] It should be understood that when the light spot moves along the first path S1 or the third path S3, if the movement of the battery cell 600 from back to front is synchronized with the movement of the light spot from back to front, the area swept by the light spot on the battery cell 600 is parallel to the lateral direction; if the movement of the battery cell 600 from back to front is not synchronized with the movement of the light spot from back to front, the area swept by the light spot on the battery cell 600 is inclined relative to the lateral direction.

[0060] like Figure 1 As shown, in one embodiment of the present invention, the third path S3 starts from the third point O 3 Move to the fourth point O on the first side of the battery cell 600 4 , the scanning path also includes the fourth point O 4 Move back to the first point O 1 Thus, the scanning path is generally in the shape of a figure 8 or an hourglass, and the light spot is cyclically scanned along the scanning path in the shape of a figure 8 or an hourglass.

[0061] Specifically, the first path S1 extends obliquely from the back to the front, and when the light spot moves along the first path S1, it not only moves from the first side to the second side in the transverse direction, but also moves forward a certain distance in the front-to-back direction. As described above, the third path S3 extends obliquely from the back to the front, and when the light spot moves along the third path S3, it not only moves from the second side to the first side in the transverse direction, but also moves forward a certain distance in the front-to-back direction.

[0062] First point O 1 and the second point O 2 The distance in the front-back direction, the third point O 3 and the fourth point O 4 The distance in the front-to-back direction and the second point O 2 and the third point O 3 The distances in the front-to-back direction are all equal to H. The distance that the light spot moves forward when it moves along the first path S1 is H, and the distance that the light spot moves forward when it moves along the third path S3 is also H.

[0063] It can be imagined that in the above case, the fourth point O 4 and the first point O 1 The distance in the front-to-back direction is also equal to H. In the process of the light spot completing one scan, the distance that the battery cell 600 moves forward is equal to 2H.

[0064] In this embodiment, both ends of the first path S1 and both ends of the third path S3 extend beyond the battery cell 600 in the lateral direction. Thus, when the light spot moves along the first path S1 and the third path S3, it can completely scan the battery cell 600 in the lateral direction. The light spot scans in a cycle multiple times along the scanning path, and the scanned area can cover the battery cell 600.

[0065] Those skilled in the art can imagine that the length of the first path S1 and the length of the third path S3 are related to the size of the battery cell 600 in the lateral direction, and the length of the second path S2 (i.e., the length of the second point O 2 and the third point O 3 The length of the fourth path S4 (i.e., the fourth point O 4 and the first point O 1 The distance in the front-to-back direction) is related to the size H occupied by the light spot in the front-to-back direction. For example, in this embodiment, the size occupied by the battery cell 600 in the transverse direction is 182mm, the length of the first path S1 and the third path S3 is slightly larger than 182mm, about 190mm, and the length of the second path S2 and the fourth path S4 are both equal to H, H is 2.5mm. Obviously, the length of the first path S1 and the length of the third path S3 are much larger than the length of the second path S2 and the fourth path S4. Therefore, in the process of moving along the scanning path, the light spot spends most of its time moving along the first path S1 and the third path S3, and the time moving along the second path S2 and the fourth path S4 is negligible.

[0066] Specifically, the ratio of the length of the first path S1 or the third path S3 to the size H of the light spot in the front-to-back direction is not less than 10.

[0067] The lengths of the first path S1 and the third path S3 are equal, and the lengths of the second path S2 and the fourth path S4 are also equal. If the cell 600 moves forward at a constant speed, the distance 2H that the cell 600 moves forward during a scan by the light spot can be divided into: 1 Move to the second point O 2 When the cell 600 moves forward by a distance H, the light spot moves from the third point O along the third path S3. 3 Move to the fourth point O 4 When the light spot moves forward along the first path S1, the battery cell 600 moves forward by a distance of H. Since the light spot moves forward by a distance of H when it moves along the first path S1 and by a distance of H when it moves along the third path S3, when the light spot moves along the first path S1 and the third path S3, the battery cell 600 moves synchronously with the light spot. Thus, when the light spot scans cyclically along the scanning path, the several strip-shaped areas scanned by the light spot on the battery cell 600 are parallel to the transverse direction and cover the battery cell 600, and the light spot can basically scan all areas of the battery cell 600. Figure 4 It is a schematic diagram of the moving track and the scanned area of ​​the light spot on the battery cell 600 when the light spot is scanned according to the scanning path of this embodiment.

[0068] It can be understood that the first point O 1 and the second point O 2 The distance in the front-back direction, the third point O3 and the fourth point O 4 The distance in the front-to-back direction and the second point O 2 and the third point O 3 The distance in the front-to-back direction may also be slightly larger or smaller than the size H of the light spot in the front-to-back direction.

[0069] The relationship between the moving speed of the light spot and the forward moving speed of the battery cell 600 is described below by an example. Assume that the light spot is a rectangular laser light spot of 2.5 mm*2.5 mm, and its size in the front-to-back direction is H=2.5 mm. The first point O 1 and the second point O 2 The distance in the lateral direction and the third point O 3 and the fourth point O 4 The distance in the horizontal direction is equal to 190mm. In this case, the length of the first path S1 and the third path S3 can be approximately equal to 190mm, and the length of the second path S2 and the fourth path S4 is 2.5mm. In this way, the length of the entire scanning path is approximately 190mm*2+2.5mm*2=385mm. Assuming that the transmission speed of the battery cell 600 is 300mm / s, the time required for it to move forward a distance of 2H is 5mm÷300mm / s=0.017s, and the moving speed of the light spot should be 385mm÷0.017s=22647mm / s. In summary, if the transmission speed of the battery cell 600 is 300mm / s, the moving speed of the light spot should be 22647mm / s, so that the area scanned by the light spot can basically cover the battery cell 600. If the transmission speed of the battery cell 600 is greater than 300 mm / s, some areas on the battery cell 600 will not be scanned, resulting in missed scanning. On the contrary, some areas on the battery cell 600 will be scanned repeatedly.

[0070] It is conceivable that in some scenarios, the moving speed of the light spot or the forward transmission speed of the battery cell 600 can be adjusted to meet special requirements of missed scanning or repeated scanning.

[0071] like Figure 2 As shown, in another embodiment of the present invention, the third path S3 starts from the third point O 3 Move to the first point O 1 In this way, the scanning path is triangular, and the light spot scans cyclically along the triangular scanning path.

[0072] Specifically, the first path S1 extends obliquely from the back to the front, and when the light spot moves along the first path S1, it not only moves from the first side to the second side in the transverse direction, but also moves forward a certain distance in the front-to-back direction. As described above, the third path S3 extends obliquely from the back to the front, and when the light spot moves along the third path S3, it not only moves from the second side to the first side in the transverse direction, but also moves forward a certain distance in the front-to-back direction.

[0073] First point O 1 and the second point O 2 The distance in the front-to-back direction and the third point O 3 and the first point O 1 The distances in the front and rear directions are all equal to 0.5H. It can be imagined that in the above case, the second point O 2 and the third point O 3 The distance in the front-to-back direction is H. During the process of the light spot completing one scan, the distance that the battery cell 600 moves forward is H.

[0074] It can be seen that the lengths of the first path S1 and the third path S3 are equal. If the cell 600 moves forward at a constant speed, the distance H that the cell 600 moves forward during the process of the light spot completing a scan can be divided into: the distance H that the light spot moves forward from the first point O along the first path S1 1 Move to the second point O 2 When the battery cell 600 moves forward by a distance of 0.5H, the light spot moves from the third point O along the third path S3. 3 Move to the first point O 1 When the light spot moves forward along the first path S1, the battery cell 600 moves forward by a distance of 0.5H. Since the light spot moves forward by a distance of 0.5H when it moves along the first path S1 and by a distance of 0.5H when it moves along the third path S3, the battery cell 600 moves synchronously with the light spot when the light spot moves along the first path S1 and the third path S3. In this way, when the light spot scans cyclically according to the scanning path, the several strip-shaped areas scanned by the light spot on the battery cell 600 are parallel to the transverse direction and cover the battery cell 600, and the light spot can basically scan all areas of the battery cell 600. When the light spot scans according to the scanning path of this embodiment, the moving trajectory and the schematic diagram of the scanned area on the battery cell 600 are similar to Figure 4 similar.

[0075] Figure 3 FIG. 1 shows another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that in this embodiment, the first path S1 is parallel to the transverse direction, that is, the first point O 1 and the second point O 2 The distance in the front-to-back direction is 0, and the light spot moves along the first path S1, moving from the first side to the second side in the transverse direction, but its position in the front-to-back direction remains unchanged. 3 and the first point O 1 The distance in the front-to-back direction is H, and the light spot moves along the third path S3, not only moving from the second side to the first side, but also moving forward a distance of H in the front-to-back direction.

[0076] In this embodiment, the length of the third path S3 is slightly greater than the length of the first path S1, and the two can be approximately equal. If the cell 600 moves forward at a constant speed, the distance H that the cell 600 moves forward during the process of the light spot completing a scan can be divided into: the distance H that the light spot moves forward from the first point O along the first path S1 1 Move to the second point O 2 When the battery cell 600 moves forward by a distance of 0.5H, the light spot moves from the third point O along the third path S3. 3 Move to the first point O 1 When the light spot moves forward along the first path S1, the distance moved forward is 0.5H. Therefore, the movement of the battery cell 600 and the light spot is not synchronized, and the difference between the moving distances is 0.5H. Accordingly, the strip area swept by the light spot on the battery cell 600 extends obliquely from front to back relative to the transverse direction. When the light spot moves forward along the third path S3, the distance moved forward is H. Therefore, the movement of the battery cell 600 and the light spot is not synchronized, and the difference between the moving distances is 0.5H. Accordingly, the strip area swept by the light spot on the battery cell 600 extends obliquely from back to front relative to the transverse direction. When the light spot is scanned according to the scanning path of this embodiment, the moving trajectory on the battery cell 600 and the schematic diagram of the swept area are the same as those in FIG. Figure 5 similar.

[0077] When the light spot scans cyclically according to the scanning path of this embodiment, the strip area swept on the battery when the light spot moves along the first path S1 and the strip area swept on the battery cell 600 when the light spot moves along the third path S3 are parallel and cover the battery cell 600, and the light spot can basically sweep all areas of the battery cell 600.

[0078] like Figure 6-21 As shown, the present invention further provides a cell laser sintering device, which includes a laser sintering module 300 . The laser sintering module 300 processes the cell 600 using the above-mentioned laser sintering method.

[0079] The laser sintering module 300 includes at least two groups of powered roller assemblies 302 arranged along the front-to-back direction and a laser assembly 301 for emitting laser light between the two groups of powered roller assemblies 302 .

[0080] The power roller assembly 302 includes an upper roller 302a and a lower roller 302b that are arranged opposite to each other in the up-down direction. The upper roller 302a and the lower roller 302b can be driven to rotate by a drive motor, a transmission assembly, and other structures. The battery sheet 600 can be arranged between the upper roller 302a and the lower roller 302b, and driven by the upper roller 302a and the lower roller 302b to move from back to front, and the upper roller 302a and the lower roller 302b are respectively connected to the positive electrode and the negative electrode of the power supply 302c to apply a reverse voltage to the battery sheet 600.

[0081] The laser assembly 301 includes a laser source 301a, a laser shaping module 301b, a galvanometer 301c and a field lens 301d. The laser source 301a is used to emit laser light, the laser shaping module 301b is used to shape the spot of the laser light emitted by the laser source 301a into a square or a circle, the galvanometer 301c is used to receive the shaped laser light and adjust the scanning position, scanning amplitude and scanning speed of the laser spot according to the scanning parameters, and the field lens 301d is fixedly connected to the galvanometer 301c and is used to focus the laser light onto the surface of the battery cell 600 to form a spot on the surface of the battery cell 600.

[0082] It is conceivable that in order to make the light spot formed by the laser emitted by the laser component 301 on the plane where the battery cell 600 is located move according to a preset scanning path, the laser sintering module 300 may also include a driving component for driving the laser component 301 to move.

[0083] The cell laser sintering method and cell laser sintering equipment provided by the present invention apply voltage to the cell 600 during the transportation of the cell 600, and emit laser toward the cell 600 during the transportation of the cell 600. The light spot formed by the laser on the plane where the cell 600 is located moves according to a preset scanning path. The area scanned by the laser can cover the cell 600 well, and the energy applied to the cell 600 is moderate.

[0084] Specifically, the upper roller 302a and the lower roller 302b each include a rotating shaft 3020, and a contact ring 3024 sleeved on the rotating shaft 3020 for contacting the battery cell 600. Each upper roller 302a and each lower roller 302b are provided with only one contact ring 3024, wherein the contact ring 3024 on the upper roller 302a is a first contact ring 3024a, and the contact ring 3024 on the lower roller 302b is a second contact ring 3024b. On the battery cell 600, the surface contacted by the first contact ring 3024a is the front surface, and the surface contacted by the second contact ring 3024b is the back surface. The outer peripheral surface of the contact ring 3024 is annular and has a length extending in the transverse direction, and the transverse direction is perpendicular to the front-back direction. In this way, the contact ring 3024 has a sufficient contact area to contact the battery cell 600 , so that the battery cell 600 is not easily crushed, and the contact ring 3024 also has a sufficient area to contact the battery cell 600 to apply voltage to the battery cell 600 .

[0085] It should be noted that, in this article, the front-to-back direction refers to the direction in which the laser sintering module 300 is located. Fig. 9 The left and right directions in the state shown, where the left side is the rear side, the right side is the front side, and the transverse direction is the laser sintering module 300 in the state shown Figure 7 Left and right direction in the displayed state.

[0086] The laser sintering module 300 further includes a power supply 302c, at least one of all the first contact rings 3024a is electrically connected to one of the positive and negative electrodes of the power supply 302c, and at least one of all the second contact rings 3024b is electrically connected to the other of the positive and negative electrodes of the power supply 302c. In this way, when the power roller assembly 302 conveys the battery cell 600, the power supply 302c can apply voltage to the battery cell 600 through at least one first contact ring 3024a and at least one second contact ring 3024b.

[0087] In a specific configuration, the negative pole of the power source 302c is electrically connected to the first contact ring 3024a, and the positive pole is electrically connected to the second contact ring 3024b. Alternatively, the positive pole of the power source 302c is electrically connected to the first contact ring 3024a, and the negative pole is electrically connected to the second contact ring 3024b.

[0088] The rotating shaft 3020 includes a main shaft 3021, an insulating layer 3022 sleeved on the main shaft 3021, and a conductive layer 3023 sleeved on the insulating layer 3022. The contact ring 3024 is sleeved on the conductive layer 3023. The power source 302c is connected to the contact ring 3024 through the conductive layer 3023. At least one of the conductive layers 3023 on all the upper rollers 302a is electrically connected to one of the positive and negative electrodes of the power source 302c, and at least one of the conductive layers 3023 on all the lower rollers 302b is electrically connected to the other of the positive and negative electrodes of the power source 302c. The main shaft 3021 is a metal shaft with high structural strength. The insulating layer 3022 separates the main shaft 3021 and the conductive layer 3023, so that the main shaft 3021 will not be charged.

[0089] The material of the insulating layer 3022 may be insulating rubber. The material of the conductive layer 3023 may be one of copper, graphite, carbon fiber, aluminum, silver, etc. The material of the contact ring 3024 may be one of conductive silicone rubber, copper, carbon fiber, etc. Conductive silicone rubber is preferably used, which is conductive and flexible, so that the contact ring 3024 is not easy to crush the battery cell 600.

[0090] Conductive silicone rubber refers to silicone rubber in which conductive particles such as silver-plated glass, silver-plated aluminum, silver-plated copper, and pure silver are uniformly distributed. According to the different particles filled, conductive silicone rubber can be divided into silver-plated glass conductive silicone rubber, silver-plated aluminum conductive silicone rubber, silver-plated copper conductive silicone rubber, and pure silver conductive silicone rubber. In this embodiment, the contact ring 3024 is preferably made of silver-plated copper conductive silicone rubber.

[0091] The thickness of the battery cell 600 is extremely small, usually about 100 μm. Therefore, in order to contact the battery cell 600, the gap between the first contact ring 3024a and the second contact ring 3024b that are opposite to each other up and down needs to be set to be extremely small so that the first contact ring 3024a and the second contact ring 3024b can directly contact each other. In the specific design, it is necessary to avoid short circuit between the first contact ring 3024a and the second contact ring 3024b that are opposite to each other up and down.

[0092] like Figure 7-11 As shown, in one embodiment of the present invention, all first contact rings 3024a are used to electrically connect one of the positive and negative electrodes of the power source 302c, and all second contact rings 3024b are used to electrically connect the other of the positive and negative electrodes of the power source 302c. In specific settings, all first contact rings 3024a can be used to electrically connect the negative electrode of the power source 302c, and all second contact rings 3024b can be used to electrically connect the positive electrode of the power source 302c. Alternatively, all first contact rings 3024a can be used to electrically connect the positive electrode of the positive and negative electrodes of the power source 302c, and all second contact rings 3024b can be used to electrically connect the negative electrode of the positive and negative electrodes of the power source 302c.

[0093] The laser sintering module 300 further includes a plurality of switch elements 302d, and a switch element 302d is provided between at least one of the first contact ring 3024a and the second contact ring 3024b that are opposite to each other and the power source 302c. The switch element 302d can control the on-off between at least one of the first contact ring 3024a and the second contact ring 3024b that are opposite to each other and the power source 302c, so as to prevent a short circuit from occurring when the first contact ring 3024a and the second contact ring 3024b are in contact with each other.

[0094] The switch element 302d may be disposed between the second contact ring 3024b and the power source 302c, or between the first contact ring 3024a and the power source 302c. Alternatively, the switch element 302d may be disposed between the first contact ring 3024a and the power source 302c, or between the second contact ring 3024b and the power source 302c.

[0095] When the power roller assembly 302 is conveying the battery cell 600, if there is a battery cell 600 between the first contact ring 3024a and the second contact ring 3024b, the switch element 302d is in a closed state, and the first contact ring 3024a and the second contact ring 3024b are both connected to the power source 302c, so that the first contact ring 3024a and the second contact ring 3024b can apply voltage to the battery cell 600. If there is no battery cell 600 between the first contact ring 3024a and the second contact ring 3024b, the switch element 302d is in an open state, and at least one of the first contact ring 3024a and the second contact ring 3024b is disconnected from the power source 302c, and no short circuit will occur when the two are in contact.

[0096] The switch element 302d is preferably a solid-state relay. The laser sintering module 300 may further include a control unit (such as a PLC) electrically connected to the solid-state relay. The control unit controls the on-off between the contact ring 3024 and the power source 302c through the solid-state relay.

[0097] Furthermore, the laser sintering module 300 also includes a sensing element 302e, which is arranged between the first group of powered roller assemblies 302 and the second group of powered roller assemblies 302 from back to front, so as to determine whether there is a battery cell 600 between the first group of powered roller assemblies 302 and the second group of powered roller assemblies 302.

[0098] The sensing element 302e is electrically connected to the control unit. When the sensing element 302e senses the battery cell 600, the first contact ring 3024a and the second contact ring 3024b of the first group of power-on roller shaft assemblies 302 are both connected to the power supply 302c. The subsequent control unit can calculate the position of the battery cell 600 at each subsequent moment according to the transmission speed of the battery cell 600, the size of the battery cell 600, and the distance between each group of power-on roller shaft assemblies 302 in the front-back direction, so that only when there is a battery cell 600 between the first contact ring 3024a and the second contact ring 3024b opposite to each other, both of them are connected to the power supply 302c. When the battery cell 600 is about to leave between the first contact ring 3024a and the second contact ring 3024b opposite to each other, the electrical connection between at least one of the first contact ring 3024a and the second contact ring 3024b and the power supply 302c is disconnected. In this way, no short circuit occurs between the first contact ring 3024a and the second contact ring 3024b opposite to each other.

[0099] The sensing element 302e is not limited to being disposed between the first group of powered roller components 302 and the second group of powered roller components 302 from back to front, but may also be disposed behind the first group of powered roller components 302 from back to front.

[0100] In this embodiment, the battery cell 600 is an MBB type battery cell. This type of battery cell 600 includes a main grid line and a fine grid line forming a network structure, wherein the extension direction of the main grid line ( Fig.11 The thick line part in the battery cell 600) is consistent with the transmission direction of the battery cell 600, and the thin grid line ( Fig.11 The thin line portion in the middle battery cell 600) extends in the lateral direction.

[0101] In this embodiment, the contact ring 3024 on the upper roller 302a and the lower roller 302b can apply voltage to the fine grid lines by contacting multiple main grid lines. In this case, the length of the contact ring 3024 (i.e., the size of the contact ring 3024 in the lateral direction) can be smaller than the size of the battery cell 600 in the lateral direction.

[0102] like Figure 12-15 As shown, in another embodiment of the present invention, the first contact ring 3024a and the second contact ring 3024b that are opposite to each other have different lengths, one is longer and the other is shorter, wherein the upper roller shaft 302a or the lower roller shaft 302b where the shorter contact ring 3024 is located is provided with two insulating sleeves 3024c located on both sides of the contact ring 3024 respectively.

[0103] For convenience of explanation, the longer contact ring 3024 is called a long contact ring, and the shorter contact ring 3024 is called a short contact ring. The length of the long contact ring is greater than the size of the battery cell 600 in the lateral direction, and both ends in the length direction exceed the edge of the battery cell 600. The length of the short contact ring is less than the size of the battery cell 600 in the lateral direction, and both ends in the length direction do not exceed the edge of the battery cell 600. The length of the long contact ring is equal to the length of the short contact ring plus the length of the two insulating sleeves 3024c.

[0104] For example, if the lateral dimension of the battery cell 600 is 182 mm, the length of the long contact ring needs to be greater than 182 mm, preferably 186 mm, the length of the short contact ring needs to be less than 182 mm, preferably 170 mm, and the length of the insulating sleeves 3024c on both sides is 8 mm.

[0105] To facilitate the distinction, Figure 12-15 In the figure, portions of the insulating sleeve 3024c are hatched.

[0106] The laser powered roller assembly 302 of this embodiment is suitable for applying voltage to 0BB type battery cells. Fig.15 As shown, the difference between this type of battery cell 600 and the above-mentioned MBB type battery cell is that the 0BB type battery cell has no main grid but only fine grids. When voltage is applied to it, the contact ring 3024 needs to contact all the fine grids. Therefore, the length of the contact ring 3024 needs to be greater than the size of the battery cell 600 in the lateral direction.

[0107] It can be imagined that the laser powered roller assembly 302 of this embodiment is suitable for applying voltage to 0BB type battery cells, and is also suitable for applying voltage to MBB type battery cells.

[0108] In this embodiment, among the long contact ring and the short contact ring that are opposite to each other, the length of the long contact ring is greater than the dimension of the battery cell 600 in the lateral direction, and it can contact all the fine grid lines, while the length of the short contact ring is less than the dimension of the battery cell 600 in the lateral direction. The part of the long contact ring that exceeds the battery cell 600 contacts the insulating sleeve 3024c, so that a short circuit will not occur between the upper roller 302a and the lower roller 302b.

[0109] Among the upper roller 302a and the lower roller 302b, the one with a longer contact ring 3024 is the first roller 302-L, and the one with a shorter contact ring 3024 is the second roller 302-S. In order to ensure that all fine grid lines on both sides of the battery cell 600 can contact the contact ring 3024, at least one of all the upper rollers 302a is the first roller 302-L, and at least one of all the lower rollers 302b is the first roller 302-L.

[0110] In this embodiment, at least four groups of power roller assemblies 302 are arranged in a uniform manner along the front-to-back direction, and the arrangement rules of the four upper rollers 302a and the four lower rollers 302b from back to front are as follows: the first upper roller 302a and the fourth upper roller 302a are the second roller 302-S, the second upper roller 302a and the third upper roller 302a are the first roller 302-L, the first lower roller 302b and the fourth lower roller 302b are the first roller 302-L, and the second lower roller 302b and the third lower roller 302b are the second roller 302-S. The laser assembly 301 is used to emit laser between the second upper roller 302a and the third upper roller 302a to irradiate the front of the battery cell 600.

[0111] With the above arrangement, the four areas where voltage is loaded on the front side of the cell 600 (i.e., the areas where the four upper rollers 302a are in contact with the front side of the cell 600) are symmetrically arranged on both sides of the area where the cell 600 is irradiated by the laser. This is beneficial to the sintering between the gate electrode on the cell 600 and the silicon wafer.

[0112] If the first contact ring 3024a and the second contact ring 3024b on a group of powered roller assemblies 302 are both electrically connected to the power source 302c, the group of powered roller assemblies 302 is said to be powered. When the above four groups of powered roller assemblies 302 convey the battery cell 600 from the back to the front, if the sensing element 302e senses the battery cell 600, the battery cell 600 is already located between the upper roller 302a and the lower roller 302b of the first group of powered roller assemblies 302, and thus the first group of powered roller assemblies 302 can be energized. Afterwards, as the battery cell 600 continues to move forward, the front side of the battery cell 600 passes through the second group of powered roller assemblies 302, the third group of powered roller assemblies 302, and the fourth group of powered roller assemblies 302 in sequence. Accordingly, in the subsequent conveying process of the battery cell 600, the second group of powered roller assemblies 302, the third group of powered roller assemblies 302, and the fourth group of powered roller assemblies 302 are energized in sequence.

[0113] During the conveying process of the battery cell 600 from back to front, the rear side of the battery cell 600 will leave the first group of power-on roller assemblies 302, the second group of power-on roller assemblies 302, the third group of power-on roller assemblies 302, and the fourth group of power-on roller assemblies 302 in sequence. Therefore, during the conveying process of the battery cell 600, the first group of power-on roller assemblies 302, the second group of power-on roller assemblies 302, the third group of power-on roller assemblies 302, and the fourth group of power-on roller assemblies 302 are powered off in sequence.

[0114] It can be understood that the number of the powered roller assemblies 302 can be two, three, five or even more.

[0115] In addition to the above-mentioned arrangement rules, in another embodiment of the present invention, the arrangement rule of the four upper rollers 302a and the four lower rollers 302b from back to front can also be: the first upper roller 302a and the third upper roller 302a are the second roller 302-S, the second upper roller 302a and the fourth upper roller 302a are the first roller 302-L, the first lower roller 302b and the third lower roller 302b are the first roller 302-L, and the second lower roller 302b and the fourth lower roller 302b are the second roller 302-S.

[0116] In another embodiment of the present invention, the arrangement pattern of the four upper rollers 302a and the four lower rollers 302b from back to front can also be: the first upper roller 302a and the third upper roller 302a are the first roller 302-L, the second upper roller 302a and the fourth upper roller 302a are the second roller 302-S, the first lower roller 302b and the third lower roller 302b are the second roller 302-S, and the second lower roller 302b and the fourth lower roller 302b are the first roller 302-L.

[0117] In another embodiment of the present invention, the arrangement rule of the upper rollers 302a and the lower rollers 302b may also be: all the upper rollers 302a are the first rollers 302-L, and all the lower rollers 302b are the second rollers 302-S.

[0118] In another embodiment of the present invention, the arrangement pattern of the four upper rollers 302a and the four lower rollers 302b from back to front may also be: the first upper roller 302a and the fourth upper roller 302a are the first roller 302-L, the second upper roller 302a and the third upper roller 302a are the second roller 302-S, the first lower roller 302b and the fourth lower roller 302b are the second roller 302-S, and the second lower roller 302b and the third lower roller 302b are the first roller 302-L.

[0119] like Figures 16 to 21 As shown, in addition to the laser sintering module 300 , the cell laser sintering equipment provided by the present invention further includes a transmission component 303 , a support seat 304 and a lifting component 305 .

[0120] The transmission assembly 303 is used to realize the transmission between the upper roller shaft 302a and the lower roller shaft 302b.

[0121] The support seat 304 is used to install the lower roller shaft 302b.

[0122] The lifting assembly 305 is used to drive the upper roller 302a to move in the up and down directions so as to move toward or away from the lower roller 302b.

[0123] The lower roller shaft 302b is provided in plurality, and the plurality of lower roller shafts 302b are arranged along the transmission direction of the battery sheet. Both ends of the lower roller shaft 302b are rotatably mounted on the top of the support seat 304 through bearings 302b-2.

[0124] The laser sintering module 300 further includes a lifting seat 302a-2 connected to the lifting assembly 305. A plurality of upper rollers 302a are provided, and the plurality of upper rollers 302a are rotatably mounted on the lifting seat 302a-2. The lifting assembly 305 drives the lifting seat 302a-2 to move in the up-down direction, and can further drive the upper roller 302a on the lifting seat 302a-2 to move in the up-down direction to adjust the distance between the lower roller 302b and the upper roller 302a.

[0125] The number of the upper roller shafts 302a and the lower roller shafts 302b is the same, and the lower roller shafts 302b and the upper roller shafts 302a are arranged one by one in the up and down direction.

[0126] In this embodiment, the lower roller 302b is located below the upper roller 302a, and the lower roller 302b is an active roller, and the upper roller 302a is a driven roller. The lower roller 302b drives the upper roller 302a to rotate through the transmission assembly 303, thereby transmitting the battery sheet between the lower roller 302b and the upper roller 302a.

[0127] The transmission assembly 303 includes a first spur gear 303a located on the upper roller shaft 302a and a second spur gear 303b located on the lower roller shaft 302b.

[0128] Specifically, the first spur gear 303a is located at the axial end of the upper roller shaft 302a, and the second spur gear 303b is located at the axial end of the lower roller shaft 302b. The first spur gear 303a and the second spur gear 303b are located on the same side. The lifting assembly 305 drives the upper roller shaft 302a to move downward, so that the second spur gear 303b and the first spur gear 303a can be meshed, so that the rotation of the lower roller shaft 302b can synchronously drive the upper roller shaft 302a to rotate. The lifting assembly 305 drives the upper roller shaft 302a to move upward, so that the second spur gear 303b and the first spur gear 303a can be separated, so as to remove the battery cell fragments between the lower roller shaft 302b and the upper roller shaft 302a.

[0129] Reference Fig. 20 In one embodiment, the lifting seat 302a-2 includes a first connecting plate 302a-21 connected to the lifting assembly 305, and two second connecting plates 302a-22 located on both sides of the first connecting plate 302a-21. The upper roller 302a is rotatably installed between the two second connecting plates 302a-22.

[0130] Specifically, the first connecting plate 302a-21 extends in a direction parallel to the upper roller shaft 302a. The two second connecting plates 302a-22 are respectively located on both sides of the first connecting plate 302a-21, and the second connecting plates 302a-22 are perpendicular to the first connecting plate 302a-21, and extend in the battery sheet transmission direction.

[0131] The lifting assembly 305 includes a support frame 305a and a driving member 305b located on the support frame 305a. The lifting seat 302a-2 is connected to the output end of the driving member 305b.

[0132] The upper roller shaft 302a is rotatably mounted between the two second connecting plates 302a-22 via self-aligning bearings 302a-3 located at both ends thereof. The inner ring of the self-aligning bearing 302a-3 can rotate relative to the outer ring by a certain angle, so that the upper roller shaft 302a can keep rotating at a certain tilt angle.

[0133] A rotation drive member 307 is also installed on the support seat 304, and the rotation drive member 307 is used to drive the lower roller shaft 302b to rotate. The rotation drive member 307 includes a drive motor and a drive shaft. The output end of the drive motor is connected to the drive shaft through a belt. The drive shaft extends along the arrangement direction of the lower roller shaft 302b. The drive shaft is provided with a first bevel gear at intervals, and the lower roller shaft 302b is provided with a second bevel gear meshing with the first bevel gear.

[0134] When the driving motor is started, the driving shaft is driven to rotate through the belt, and the driving shaft drives the lower roller 302b to rotate through the first bevel gear and the second bevel gear, thereby realizing the transmission of the battery sheet.

[0135] It should be understood that although the present specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0136] The above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person skilled in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A method for laser sintering a battery cell, characterized in that: The steps include: Applying voltage to the battery cell and conveying the battery cell from back to front in a front-to-back direction; emitting a laser toward the battery cell, wherein when the laser is emitted, a dot-shaped light spot is formed on the plane where the battery cell is located; Moving the laser so that the light spot performs multiple cycles of scanning along a preset scanning path; Assuming that in a transverse direction perpendicular to the front-rear direction, the two sides of the battery sheet are respectively a first side and a second side, the scanning path includes a first path moving from a first point on the first side to a second point on the second side, a second path moving backwards from the second point to a third point, and a third path moving from the third point to the first point on the first side, and the first point is a starting point and an end point of the scanning path; The first path extends obliquely from the rear to the front or is parallel to the lateral direction, and the third path extends obliquely from the rear to the front.

2. The cell laser sintering method according to claim 1, characterized in that: The first path extends obliquely from back to front, the size of the light spot in the front-to-back direction is H, the distance between the first point and the second point in the front-to-back direction and the distance between the third point and the first point in the front-to-back direction are both equal to 0.5H, and the distance the battery cell moves forward during a scan completed by the light spot is H.

3. The cell laser sintering method according to claim 1, characterized in that: The first path is parallel to the transverse direction, the size of the light spot in the front-to-back direction is H, the distance between the first point and the second point in the front-to-back direction is 0, the distance between the third point and the first point in the front-to-back direction is H, and the distance the battery cell moves forward during a scan by the light spot is H.

4. The cell laser sintering method according to any one of claims 1 to 3, characterized in that: Both ends of the first path and both ends of the third path extend beyond the battery cell in a lateral direction.

5. The cell laser sintering method according to any one of claims 1 to 3, characterized in that: The ratio of the length of the first path or the third path to the size H of the light spot in the front-to-back direction is not less than 10.

6. The cell laser sintering method according to claim 1, characterized in that: The wavelength of the laser is 400nm-1200nm, the power is 10W-300W, and the size H of the light spot in the front-back direction is 0.05mm-10mm.

7. The cell laser sintering method according to claim 1, characterized in that: The shape of the light spot is square or circular.

8. A cell laser sintering device, characterized in that: It comprises a laser sintering module, and the laser sintering module uses the battery cell laser sintering method according to any one of claims 1 to 7 to process the battery cell.

9. The laser sintering equipment according to claim 8, characterized in that: The laser sintering module comprises at least two groups of powered roller assemblies arranged in the front-to-back direction, and a laser assembly for emitting laser light between the two groups of powered roller assemblies; The power-on roller assembly comprises an upper roller and a lower roller that are arranged opposite to each other in the up-down direction. The upper roller and the lower roller are respectively connected to the positive electrode and the negative electrode of the power source to apply a reverse voltage to the battery cell.

10. The laser sintering equipment according to claim 9, characterized in that: The upper roller and the lower roller each include a rotating shaft and a contact ring sleeved on the rotating shaft for contacting the battery sheet, and each of the upper roller and each of the lower rollers is only provided with one contact ring; The rotating shaft comprises a main shaft, an insulating layer sleeved on the main shaft, and a conductive layer sleeved on the insulating layer. The contact ring is sleeved on the conductive layer, and the power source is connected to the contact ring through the conductive layer.

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