Battery piece welding tool and technological method

Abstract

The invention discloses a battery piece welding tool and process method, and belongs to the technical field of battery piece welding. The battery piece welding tool comprises a pressing needle tool and a lamp box; a battery piece to be welded is arranged on the pressing needle tool; a plurality of welding strips are arranged at the upper ends of the battery pieces; a hollow part is arranged in the middle of the needle pressing tool; the lamp box adopts an infrared lamp tube as a light source; the infrared lamp tube adopts condensation irradiation, and an irradiation beam corresponds to the hollow part; the hollow part corresponds to the welding spot; the number of the infrared lamp tubes corresponds to the number of welding points on the welding strip; a reflective coating is arranged on the inner side wall of the infrared lamp tube, and the reflective coating is a zirconium oxide reflective layer or a gold plating layer; the wrapping angle of the lamp tube reflecting layer of the infrared lamp tube is 270-330 degrees; a bottom plate capable of being preheated is arranged at the lower end of the battery piece, and the bottom plate abuts against the battery piece. The light condensation capability of the infrared lamp tube can be improved, the warping degree of a battery piece after welding is completed is reduced through different welding modes, and the hidden crack risk of the battery piece is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cell welding, and more specifically, to a battery cell welding tool and a process method. Background Art

[0002] The soldering tape is an important structure for improving the efficiency and reducing the cost of photovoltaic modules. Photovoltaic modules connect multiple cells in series through the soldering tape to collect current. In traditional technology, infrared lamps or electric soldering irons are generally used to solder the soldering tape to the pads of the cells.

[0003] When the battery cell and the welding ribbon are serially welded, the welding ribbon is located on the back of the battery cell. Due to the different thermal expansion coefficients of the welding ribbon and the battery cell, the shrinkage of the welding ribbon is greater than the shrinkage of the battery cell during the welding cooling process, and the welding ribbon will pull the battery cell horizontally. At present, the welding of battery cells and welding ribbons usually adopts infrared light box heating welding. The infrared light box irradiates the entire width of the battery cell. At this time, the entire welding ribbon is heated and welded with each welding point (referred to as welding point) on the battery cell at the same time, resulting in a large shrinkage of the welding ribbon after cooling. The battery cell will form a higher arch (i.e. warp) in the direction of the non-welding surface. The higher arch will cause the battery cell to have a greater risk of hidden cracks during lamination. In addition, the existing welding light boxes all use tunnel-type light boxes. The temperature change of tunnel-type light boxes is small, but the heating time is long. When the welding ribbon and the battery are welded on both sides, the welding ribbon and the battery cell are heated evenly, which can reduce the false welding rate; the deformation of the welding ribbon is different from the deformation of the battery cell. When the welding ribbon and the battery cell are welded on one side, the battery cell warps greatly. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a battery cell welding tool and process method, which can improve the focusing ability of infrared lamps, reduce the warping of battery cells after welding through different welding methods, and reduce the risk of hidden cracks in battery cells.

[0005] To solve the above problems, the present invention adopts the following technical solutions.

[0006] A battery cell welding tool, comprising a needle pressing tool and a light box;

[0007] The battery cells to be welded are arranged on the pressing tool; a plurality of welding strips are arranged on the upper end of the battery cells;

[0008] A hollow portion is provided in the middle of the needle pressing tool; the light box adopts an infrared lamp tube as a light source; the infrared lamp tube adopts concentrated irradiation, and the irradiation light beam corresponds to the hollow portion; the hollow portion corresponds to the welding point; the number of infrared lamp tubes corresponds to the number of welding points on the welding strip; the inner wall of the infrared lamp tube is provided with a reflective coating, and the reflective coating is a zirconium oxide reflective layer or a gold plating layer; the wrapping angle of the lamp tube reflective layer of the infrared lamp tube is 270°~330°; a preheatable bottom plate is provided at the lower end of the battery cell, and the bottom plate and the battery cell are abutted against each other.

[0009] Furthermore, the circumference of the reflective coating is smaller than the circumference of the inner wall of the infrared lamp tube, and the circumference of the reflective coating is greater than half of the circumference of the inner wall of the infrared lamp tube; a focusing port is formed between the two ends of the reflective coating, and the direction of the focusing port is always toward the hollow part of the needle pressing tooling.

[0010] Furthermore, the light box includes lamp tube fixings evenly placed on the upper end of the needle pressing tooling, and the lamp tube fixings are arranged corresponding to the hollow part of the needle pressing tooling; the infrared lamp tube is placed in the lamp tube fixings, and the infrared lamp tube abuts against the inner wall of the lamp tube fixings; a plurality of evenly arranged fans are also arranged at the upper or lower end of the light box, and the wind direction of the fans is always toward the infrared lamp tube and the welding strip, and the fans are detachably connected to the upper end of the light box.

[0011] The present invention also discloses a battery cell welding process method, comprising the following steps:

[0012] Place the soldering tape at the corresponding position of the battery cell, place the battery cell on the bottom plate and under the pressing needle tool at the same time, and the soldering point of the soldering tape corresponds to the hollow part; the bottom plate preheats the battery cell and the soldering tape; finally, light up the infrared lamp to weld the soldering point; the welding time is 2s to 9s; the welding power is 1kw to 5kw; the preheating temperature of the bottom plate is 70℃ to 150℃.

[0013] Furthermore, corresponding soldering points on the plurality of soldering strips are located in the same direction, and the soldering points in the same direction correspond to the infrared lamps in the same direction in sequence; and a plurality of infrared lamps in at least one column form a group.

[0014] Furthermore, the multiple infrared lamp tubes in each group are started in sequence from both sides; first, the outermost infrared lamp tubes at both ends of the same group are started, and then the adjacent inner infrared lamp tubes are started, and the adjacent inner infrared lamp tubes are started in sequence in this direction until the middle infrared lamp tube is started to complete the welding.

[0015] Furthermore, the multiple infrared lamp tubes in each group are started in sequence from the middle to both sides; first, the middle infrared lamp tube in the same group is started, and then the adjacent outer infrared lamp tubes are started, and the adjacent outer infrared lamp tubes are started in sequence in this direction until the infrared lamp tubes at the outermost ends are started to complete the welding.

[0016] Furthermore, the multiple infrared lamp tubes in each group are started unidirectionally from one end to the other end; first, the outermost infrared lamp tube at one end of the same group is started, and then the adjacent inner infrared lamp tubes are started, and the adjacent inner infrared lamp tubes are started in sequence in this direction until the outermost infrared lamp tube at the other end is started to complete the welding.

[0017] Furthermore, the multiple infrared lamps in the same group are started at the same time; the multiple infrared lamps in each group are started as a whole at the same time to complete the welding.

[0018] Furthermore, the multiple infrared lamp tubes in the same group are started one by one in sequence; the multiple infrared lamp tubes in the same group are started one by one in sequence from the first to the last position of each welding strip; the first strip is welded first, and then the infrared lamp tubes corresponding to the adjacent welding strips are started, and in this way, the multiple infrared lamp tubes on each welding strip are started in sequence to complete the welding.

[0019] Furthermore, during the welding process, the welding ribbon is welded to the welding point and / or solder paste; after the welding of the battery cell is completed, the remaining welding points where the solder paste is not used are coated with solder flux; the entire welding ribbon is pre-soaked in the solder flux.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] Compared with the tunnel-type light box in the prior art, this solution sets the light box as a spotlight-type light box. By increasing the circumference of the reflective coating in the infrared lamp tube, the spotlight effect is greatly improved, and a zirconium oxide reflective layer is used to increase the spotlight effect of the infrared lamp tube. Compared with the tunnel-type light box, the warpage of the spotlight-type light box is within 2m, and the spotlight welding effect is better than the tunnel-type light box. And the welding is carried out by a two-way relative aggregation method. It is also experimentally concluded that the warpage of the welding is better than the ordinary conventional welding method in a variety of welding methods, so as to reduce the risk of hidden cracks in the battery cell. At the same time, the bottom plate of the battery cell is preheated. The above-mentioned spotlighting and preheating treatment methods are in line with the characteristics of the silicon wafer, and meet the thermal conductivity and optical characteristics. At the same time, this solution also changes the original method of setting solder paste on both sides to placing it from the middle to both sides, and changes the original liquid state of the solder paste to a semi-solid state, so that the solder paste can extend to both sides of the solder strip after being heated and dissolved, so that the flatness of the solder strip is better. Finally, after the battery cells are welded, apply flux to the solder joints without solder paste to reduce the false soldering rate, and soak the solder strips in flux in advance to improve the welding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of an optional embodiment of the present invention;

[0023] Figure 2 It is a front view structural schematic diagram of the overall tooling of the present invention;

[0024] Figure 3 It is a schematic diagram of the enlarged structure of the infrared lamp tube of the present invention;

[0025] Figure 4 It is a schematic diagram of the first bidirectional facing aggregation welding of the present invention;

[0026] Figure 5 It is a schematic diagram of the second bidirectional relative aggregation welding of the present invention;

[0027] Figure 6 This is a schematic diagram of the third type of sequential row-by-row welding of the present invention;

[0028] Figure 7 It is a schematic diagram of the fourth type of overall simultaneous welding of the present invention;

[0029] Figure 8 This is a schematic diagram of the fifth type of welding in sequence according to the present invention;

[0030] Fig. 9 Schematic diagram of the warping position of the battery cells in the embodiment of the present invention and the comparative example 1.

[0031] Description of the numbers in the figure:

[0032] Battery cell 1, bottom plate 11, solder strip 2, solder joint 3, needle pressing tool 4, light box 5, lamp tube fixing part 51, infrared lamp tube 52, reflective coating 521, fan 6. DETAILED DESCRIPTION

[0033] A battery cell welding tool, please refer to Figure 1-3, including a battery cell 1, the battery cell 1 is placed on a welding strip 2, and a plurality of welding points 3 are arranged on the welding strip 2. The welding points 3 here refer to the points to be welded between the welding strip 2 and the battery cell 1, and the points to be welded can be welding pads pre-set on the battery cell 1. Usually, the number of points to be welded between each welding strip 2 of the multiple welding strips 2 and the battery cell 1 is the same. A preheatable bottom plate 11 is provided at the lower end of the battery cell 1, and the bottom plate 11 and the battery cell 1 are in contact with each other. It also includes a pressing needle tool 4 provided on the welding strip 2, and a hollow part is provided in the middle position of the pressing needle tool so that the welding strip 2 and the welding point 3 are located in the middle position of the hollow part. The welding point 3 is located between the welding strip 2 and the battery cell 1, and the pressing needle tool 4 is suspended at the upper end of the welding strip 2, and a light box 5 is provided at the upper end of the pressing needle tool 4, and the light box 5 and the pressing needle tool 4 are in contact with each other. The light box 5 comprises lamp tube fixing parts 51 evenly arranged on the upper end of the needle pressing tool 4, and the lamp tube fixing parts 51 are arranged corresponding to the hollowed-out part of the needle pressing tool 4. The light box 4 is a spotlight type light box.

[0034] An infrared lamp tube 52 is arranged inside the lamp tube fixture 51, and the infrared lamp tube 52 abuts against the inner wall of the lamp tube fixture 51. The focusing direction of the infrared lamp tube 52 is aligned with the hollow part of the needle pressing tool 4, so that the infrared lamp tube 52 focuses and irradiates on the solder joint 3 and the solder strip 2 to form a solder joint. A reflective coating 521 is arranged on the inner side of the lamp wall of the infrared lamp tube 52, and the setting circumference of the reflective coating 521 is smaller than the circumference of the inner wall of the infrared lamp tube 52, and the setting circumference of the reflective coating 521 is greater than half of the circumference of the inner wall of the infrared lamp tube 52. A focusing port is formed between the two ends of the reflective coating 521, and the direction of the focusing port is always toward the hollow part of the needle pressing tool 4, so that the focusing direction always irradiates through the through hole and irradiates the solder joint 3. The upper end and / or lower end of the light box 5 is also provided with a plurality of evenly arranged fans 6, the wind direction of the fans 6 is always toward the infrared lamp tube 52 and the welding strip 2, and the fans 6 are detachably connected to the upper end of the light box 5. The fans 6 are connected to the outer driving member so that the fans 6 have the ability to rotate.

[0035] The reflective coating 521 of the infrared lamp tube 52 is a zirconium oxide reflective layer or a gold reflective layer, and the wrapping angle of the reflective coating of the infrared lamp tube 52 is 270° to 330°, preferably 270°. The temperature of the bottom plate 11 is 70° to 150°, preferably 110°. The welding time is 2s to 9s, preferably 3s. The welding power is 2kw.

[0036] A battery cell welding process method, according to the above welding tool, comprises the following steps:

[0037] First, place the soldering tape 2 at the corresponding position of the battery cell 1, and place the battery cell 1 on the bottom plate 11, and at the same time place the battery cell 1 under the pressing needle tool 4, so that the soldering point 3 on the soldering tape 2 corresponds to the hollow part on the pressing needle tool 4; before welding, the bottom plate 11 preheats the battery cell 1 and the soldering tape 2. During welding, light up the infrared lamp 52 to weld the soldering point 3.

[0038] The welding process includes the welding form of welding the solder joint 3 and the solder strip 2 separately, or the welding form of welding the soldering filler separately, or the welding form of directly welding the solder joint 3 on the solder strip 2 and setting the soldering filler on the solder joint 3. Preferably, the solder joint 3 uses solder paste as the soldering filler. When the form of welding the soldering filler separately is adopted, the solder paste is located between two separated solder joints 3. In this form, the solder paste is not semi-solid, and the shape of the solder paste is raised; after the solder strip is heated, the solder paste dissolves the tin on the solder strip, and the dissolved tin flows to the solder joints 3 on both sides, and forms tin beads after cooling and solidification to wrap the solder strip 2 and cover the solder joint 3. When the form of directly welding the solder joint 3 on the solder strip 2 and setting the soldering filler on the solder joint 3 is adopted, the solder paste is located on the corresponding solder joint 3. In this form, the solder paste is liquid solder paste to directly wrap the solder strip 2 and cover the solder joint 3.

[0039] After the battery cell 1 is welded, due to oxidation of the battery cell 1, a flux is applied to the solder joints 3 without solder paste to reduce the false soldering rate (the soldering strip 2 has been soaked in flux).

[0040] Example 1: Please refer to Figure 4-8 , the number of welding points 3 in this embodiment is 7. In this embodiment, the welding sequence of the welding points 3 of the welding ribbon 2 on the battery cell 1 is illustrated as follows. The serial numbers of the welding points 3 along the length direction of the welding ribbon 2 are "1", "2", "3", "4", "5", "6", and "7". At the beginning of welding, the first and last ends are welded as "1" and "7"; when "1" and "7" are welded at the same time, "2" and "6" are welded again, followed by "3" and "5", and finally "4". That is, when welding, the outermost ends of the two ends are welded first, and then the adjacent inner sides are welded, and the adjacent inner sides are welded in this direction in sequence until the welding is completed in the middle. This welding method is called a bidirectional opposite aggregation welding method. When using the first welding method, it is necessary to weld simultaneously with the welding points in the same column.

[0041] Embodiment 2: Different from Embodiment 1, at the beginning of welding, "4" is welded first; after "4" is welded, "3" and "5" are welded again, followed by "2" and "6", and finally "1" and "7". It is expressed as from the middle to the two ends, and when there are two welding points, both ends are welded at the same time. This welding method is called a two-way relative diffusion welding method. When welding, the middle one is welded first, and then the adjacent outer sides are welded. The adjacent outer sides are welded in this direction in sequence until the outermost sides of both ends are welded. When using the second welding method, it is necessary to weld simultaneously with the welding points in the same column.

[0042] Embodiment 3: Different from Embodiment 1, at the beginning of welding, "1" is welded first; after "1" is welded, "2" is welded again, and then "7" is welded in sequence. This means welding from the head end to the tail end in sequence, and this welding method is called sequential welding. When using the third welding method, it is necessary to weld together with the first welding strip 2 in the same vertical direction.

[0043] Embodiment 4: Different from Embodiment 1, when welding starts, all infrared lamps 52 in the light box 5 are started, and the welding points 3 on each welding strip 2 are welded simultaneously.

[0044] Embodiment 5: Different from Embodiment 1, Figure 8 As shown in the figure, letters A to S represent the number of welding strips, and numbers 1 to 7 represent the number of welding points on each welding strip. A1 represents the first welding point on the first welding strip 2, and the remaining welding strips 2 and welding points 3 are named in the same way. At the beginning of welding, the first welding end is represented as A1; after A1 is welded, the second welding A2... the seventh welding A7, the eighth welding B1, and the last welding S7 are sequentially welded; it is represented as welding in units, row by row. That is, the welding operation is carried out one by one from the first to the last position of each welding strip 2.

[0045] Embodiment 6, on the basis of any one of embodiments 1 to 5, when using the above-mentioned multiple welding methods, in order to improve the welding speed, segmented welding is adopted, one segment is 4 infrared lamp tubes 52, one segment is 3 infrared lamp tubes 52; or one segment is 3 infrared lamp tubes 52, one segment is 4 infrared lamp tubes 52 (such as Figure 2 shown).

[0046] Experimental Example 1:

[0047] Through the above-mentioned welding tooling arrangement, the infrared lamp tube 52 is replaced with a conventional gold lamp tube, and the wrapping angle of the reflective coating inside the lamp tube is adjusted to 330°, and the preheating temperature of the bottom plate 11 is 150°C. The battery cell 1 is welded in this focusing manner, and the welding time is 9s. The welded battery cell 1 is measured and the warpage of different positions of the battery cell 1 is recorded, and the following Table 1 is obtained:

[0048] Table 1 Measurement data Table 1

[0049]

[0050] Comparative Example 1: The light box 5 used is a tunnel-type light box. The lamp tubes used in the light box are conventional gold lamp tubes, and are arranged at intervals of 20 mm in the light box. At the same time, the temperature of the bottom plate 11 is preheated to the same temperature as the implementation method in Table 1, and then welding is performed for 9 seconds.

[0051] The battery cell 1 is welded in the manner of the comparative example 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 2 is obtained:

[0052] Table 2 Measurement data Table 2

[0053]

[0054] According to the data in Table 1 and Table 2, there is a difference in the warpage of the single-sided welded cell 1 between the spotlight box and the tunnel light box. Through the analysis of the above table data, the warpage height of the welding position of the spotlight box is smaller than that of the tunnel light box, and the welding positions in Experimental Example 1 and Comparative Example 1 are the same, so the welding effect of the spotlight box is better than that of the tunnel light box, and the warpage is within 2mm. The above data are all obtained from the first welding method from both ends to the middle.

[0055] In summary, by comparing the data in Table 1 and Table 2, and by changing the different lamps used to measure and compare the warping heights at different positions of the battery cell 1, it is found that the welding method of the focusing light box in the present invention is better than the tunnel light box used in Comparative Example 1, that is, the warping degree at each same position, the results of the experimental examples are lower.

[0056] Experimental Example 2: In this Experimental Example 2, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is an infrared lamp tube 52, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 330°. The height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0057] By the method of Experimental Example 2, the battery cell 1 was welded, and a variety of different welding methods were used, and the preheating temperature of the bottom plate was adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 was placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane was measured, and the warping degree was recorded, and the following Table 3 was obtained:

[0058] Table 3 Data comparison table 1

[0059]

[0060] Experimental Example 3: In this Experimental Example 3, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is an infrared lamp tube 52, and the wrapping angle of the reflective coating of the lamp tube is adjusted to 270°. The height of the lamp tube is set relative to the cell, and the relative distance is 22mm. The lamp power is 2kw;

[0061] By the method of Experimental Example 3, the battery cell 1 was welded, and a variety of different welding methods were used, and the preheating temperature of the bottom plate was adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 was placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane was measured, and the warping degree was recorded, and the following Table 4 was obtained:

[0062] Table 4 Data comparison with Table 2

[0063]

[0064] Experimental Example 4: In this Experimental Example 4, a spotlight box is used to weld the battery cell 1. The lamp tube used in the spotlight box is an infrared lamp tube 52, and the wrapping angle of the reflective coating of the lamp tube is adjusted to 300°. The height of the lamp tube is set relative to the battery cell, and the relative distance is 22mm. The lamp power is 2kw;

[0065] By the method of Experimental Example 4, the battery cell 1 was welded, and a variety of different welding methods were used, and the preheating temperature of the bottom plate was adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 was placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane was measured, and the warping degree was recorded, and the following Table 5 was obtained:

[0066] Table 5 Data comparison table 3

[0067]

[0068]

[0069] Comparative Example 2:

[0070] In this comparative example 2, a spotlight box is used to weld the battery cell 1. The lamp tube used in the spotlight box is an infrared lamp tube 52, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 350°, and the height of the lamp tube is set to a relative distance of 22mm relative to the battery cell, and the lamp tube power is 2kw;

[0071] By the method of comparative example 2, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 5 is obtained:

[0072] Table 5 Data comparison table 4

[0073]

[0074] Comparative Example 3:

[0075] In this comparative example 3, a spotlight box is used to weld the battery cell 1. The lamp tube used in the spotlight box is an infrared lamp tube 52, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 180°. The height of the lamp tube is set to a relative distance of 22 mm relative to the battery cell, and the lamp tube power is 2 kW.

[0076] By the method of comparative example 3, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 8 is obtained:

[0077] Table 6 Data comparison table 5

[0078]

[0079] According to the data comparison between Experimental Examples 2 to 4 and Comparative Examples 2 and 3, it is found that the infrared lamp tube 52 is used in Experimental Examples 2 to 4 and Comparative Examples 2 and 3 of the present invention, wherein the wrapping angle of the reflective coating inside the lamp tube is different. Finally, it is found that the overall welding effect of the battery cell 1 is better when the wrapping angle of the reflective coating inside the lamp tube is 270° to 330°, and the welding quality of the battery cell 1 is better.

[0080] Comparative Example 4:

[0081] In this comparative example 4, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is a conventional gold lamp tube, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 270°, and the height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0082] By the method of comparative example 4, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 7 is obtained:

[0083] Table 7 Data comparison table 6

[0084]

[0085] Comparative Example 5:

[0086] In this comparative example 5, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is a conventional gold lamp tube, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 300°, and the height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0087] By the method of comparative example 5, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 8 is obtained:

[0088] Table 8 Data comparison table 7

[0089]

[0090]

[0091] Comparative Example 6:

[0092] In this comparative example 6, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is a conventional gold lamp tube, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 330°, and the height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0093] By the method of comparative example 6, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 9 is obtained:

[0094] Table 9 Data comparison with Table 8

[0095]

[0096] According to the data comparison between Experimental Examples 2 to 4 and Comparative Examples 4, 5 and 6, it is concluded that the lamp tubes used in Experimental Examples 2 to 4 in the spotlight box of the present invention are infrared lamp tubes 52, while conventional gold lamp tubes are used in Comparative Examples 4, 5 and 6, and the wrapping angle of the reflective coating inside the lamp tubes is set to 270°~330°. The data comparison shows that Experimental Examples 2 to 4 have better overall welding effects on the battery cell 1. It can be concluded from the data that the choice of lamp tubes used in the light box has a certain influence on the welding quality, and it is found that the welding quality using infrared lamp tubes is better than that using conventional gold lamp tubes.

[0097] Comparative Example 7: In this comparative example 7, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is a conventional gold lamp tube, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 180°, and the height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0098] By the method of comparative example 7, the battery cell 1 was welded, and a variety of different welding methods were used, and the preheating temperature of the bottom plate was adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 was placed on a plane, and the warping height of the battery cell 1 at different positions relative to the plane was measured, and the warping degree was recorded, and the following Table 10 was obtained:

[0099] Table 10 Data comparison with Table 9

[0100]

[0101] Comparative Example 8: In this comparative example 8, a spotlight box is used to weld the cell 1. The lamp tube used in the spotlight box is a conventional gold lamp tube, and the wrapping angle of the reflective coating 521 in the lamp tube is adjusted to 350°, and the height of the lamp tube is set to a relative distance of 22mm relative to the cell, and the lamp tube power is 2kw;

[0102] By the method of comparative example 8, the battery cell 1 is welded, and a variety of different welding methods are used, and the preheating temperature of the bottom plate is adjusted to perform multiple welding experiments on the battery cell 1. The welded battery cell 1 is placed on a plane and the warping height of the battery cell 1 at different positions relative to the plane is measured, and the warping degree is recorded, and the following Table 11 is obtained:

[0103] Table 11 Data comparison table 10

[0104]

[0105] According to the data comparison of Experimental Examples 2 to 4 with Comparative Examples 7 and 8, it is found that the infrared lamp tube 52 is used in Experimental Examples 2 to 4 in the spotlight light box of the present invention, and the wrapping angle of the reflective coating used in the lamp tube is set to 270° to 330°. The lamp tubes used in Comparative Examples 7 and 8 are conventional gold lamp tubes, and the wrapping angles of the reflective coating used in the lamp tubes are set to 180° and 350°, both of which are outside the optimal wrapping angle of 270° to 330° of the reflective coating of the present invention. Through data analysis, it can be concluded that when the data of Experimental Examples 2 to 4 are compared with Comparative Examples 7 and 8, it is found that the factors affecting the overall welding effect of the battery cell 1 include the lamp tube used in the light box 5 and the wrapping angle of the reflective coating set in the lamp tube. From the comparative analysis of the data from Experimental Examples 2 to 4 and Comparative Examples 5 and 8, it is concluded that when the lamp tube used in the light box 5 is the infrared lamp tube 52, the overall welding effect on the battery cell 1 is better; and the wrapping angle of the reflective coating arranged in the lamp tube is in the range of 270° to 330°, the overall welding effect on the battery cell 1 is better.

[0106] According to the above data comparison tables 1 to 10, it can be seen that among all the welding methods, the warping height of different positions of the battery cell 1 in the bidirectional oppositely facing polymerization welding method is smaller than that of other welding methods under the same conditions. Therefore, it can be seen that the welding effect brought by the bidirectional oppositely facing polymerization welding method is the best.

Claims

1. A battery cell welding tool, characterized in that: It comprises a needle pressing tool (4) and a light box (5); A battery cell (1) to be welded is arranged on the needle pressing tool (4); a plurality of welding strips (2) are arranged on the upper end of the battery cell (1); A hollow portion is provided in the middle of the needle pressing tool (4); the light box (5) uses an infrared lamp tube (52) as a light source; the infrared lamp tube (52) uses concentrated light irradiation, and the irradiated light beam corresponds to the hollow portion; the hollow portion corresponds to the welding point (3); The number of infrared lamp tubes (52) corresponds to the number of solder joints on the soldering strip (2); the inner side wall of the infrared lamp tube (52) is provided with a reflective coating (521), and the reflective coating (521) is a zirconium oxide reflective layer or a gold plating layer; the wrapping angle of the lamp tube reflective layer of the infrared lamp tube is 270° to 330°; A preheatable bottom plate (11) is provided at the lower end of the battery cell (1), and the bottom plate (11) and the battery cell (1) are in contact with each other.

2. A battery cell welding tool according to claim 1, characterized in that: The circumference of the reflective coating (521) is smaller than the circumference of the inner wall of the infrared lamp tube (52), and the circumference of the reflective coating (521) is greater than half the circumference of the inner wall of the infrared lamp tube (52); a focusing port is formed between the two ends of the reflective coating (521), and the direction of the focusing port is always toward the hollow part of the needle pressing tooling (4).

3. The battery cell welding tool according to claim 1, characterized in that: The light box (5) comprises a lamp tube fixing part (51) evenly arranged on the upper end of the needle pressing tool (4), and the lamp tube fixing part (51) is arranged corresponding to the hollow part of the needle pressing tool (4); the infrared lamp tube (52) is placed in the lamp tube fixing part (51), and the infrared lamp tube (52) abuts against the inner wall of the lamp tube fixing part (51); the upper end or the lower end of the light box (5) is also provided with a plurality of evenly arranged fans (6), the wind direction of the fans (6) is always toward the infrared lamp tube (52) and the welding strip (2), and the fans (6) are detachably connected to the upper end of the light box (5).

4. A battery cell welding process, characterized in that: The battery cell welding tool according to any one of claims 1 to 3 is used; comprising the following steps: The welding strip (2) is placed at a corresponding position of the battery cell (1), the battery cell (1) is placed on a base plate (11) and at the same time the battery cell (1) is placed under a pressing needle tool (4), the welding point (3) of the welding strip (2) corresponds to the hollowed-out position; the base plate (11) preheats the battery cell (1) and the welding strip (2); the infrared lamp (52) is turned on to weld the welding point (3); the welding time is 2s to 9s; the welding power is 1kw to 5kw; the preheating temperature of the base plate (11) is 70°C to 150°C.

5. A battery cell welding process according to claim 4, characterized in that: The corresponding welding points (3) on the plurality of welding strips (2) are located in the same direction, and the welding points (3) in the same direction correspond in sequence to the infrared lamp tubes (52) in the same direction; and at least one row of the plurality of infrared lamp tubes (52) constitutes a group.

6. A battery cell welding process according to claim 5, characterized in that: The plurality of infrared lamp tubes (52) in each group are started in sequence from both sides; first, the outermost infrared lamp tubes (52) at both ends of the same group are started, and then the adjacent inner infrared lamp tubes (52) are started, and the adjacent inner infrared lamp tubes (52) are started in sequence in this direction until the middle infrared lamp tube (52) is started to complete the welding.

7. A battery cell welding process according to claim 5, characterized in that: The plurality of infrared lamp tubes (52) in each group are started in sequence from the middle to both sides; first, the middle infrared lamp tube (52) in the same group is started, and then the adjacent outer infrared lamp tubes (52) are started, and the adjacent outer infrared lamp tubes (52) are started in sequence in this direction until the infrared lamp tubes (52) at the outermost ends are started, and welding is completed.

8. A battery cell welding process according to claim 5, characterized in that: The plurality of infrared lamp tubes (52) in each group are started in a unidirectional manner from one end to the other end; first, the outermost infrared lamp tube (52) at one end of the same group is started, and then the adjacent inner infrared lamp tube (52) is started, and the adjacent inner infrared lamp tubes (52) are started in sequence in this direction until the outermost infrared lamp tube (52) at the other end is started, thereby completing welding.

9. A battery cell welding process according to claim 5, characterized in that: The plurality of infrared lamp tubes (52) in the same group are started simultaneously; the plurality of infrared lamp tubes (52) in each group are started as a whole at the same time to complete welding.

10. A battery cell welding process according to claim 4, characterized in that: The plurality of infrared lamp tubes (52) in the same group are started one by one in sequence; the plurality of infrared lamp tubes (52) in the same group are started one by one in sequence from the first to the last position of each welding strip (2); the first strip is welded first, and then the infrared lamp tubes (52) corresponding to the adjacent welding strip (2) are started, and in this way, the plurality of infrared lamp tubes (52) on each welding strip (2) are started in sequence to complete the welding.

11. A battery cell welding process according to claim 4, characterized in that: During the welding process, the welding strip (2) is welded to the welding point (3) and / or solder paste; after the welding of the battery cell (1) is completed, soldering flux is applied to the remaining parts of the welding point (3) where solder paste is not used; the welding strip (2) is soaked in soldering flux in advance.

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