Series welding machine heating device for battery pieces

Abstract

The utility model discloses a series welding machine heating device for a battery piece, which relates to the technical field of battery string processing, and comprises a first heating piece and a second heating piece, the first heating piece and the second heating piece are respectively used for heating and welding a first side surface and a second side surface of the battery piece, and the first heating piece comprises at least one welding probe; the needle point of one welding probe is used for welding one battery piece and the welding strip, the distance between the needle point of the welding probe and the pad point of the battery piece is larger than zero, the needle point of the welding probe forms point discharge, and local high temperature is generated to make contact with the welding strip; the heating device of the series welding machine does not need to heat the whole battery piece, so that the heat loss of H passivation is avoided. In the whole welding process, an infrared heating mode is not used, and infrared attenuation caused by infrared rays can also be avoided. According to the series welding machine heating device, a local loss heating mode is adopted, and a fan is not needed for heat discharge in the continuous production process; and the temperature of each point is controllable, so that the influence of non-uniformity of a thermal field on the welding effect is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery string processing, in particular to a heating device for a string welding machine of battery slices. Background Art

[0002] When the battery cells are made into components, they must first be made into battery strings. During the battery string production process, the battery cells are first cut into two symmetrical halves using a non-destructive cutting method. The solder strip is soaked in flux, straightened, and accurately placed on the previous piece. There is a pressure plate on the sheet, which ensures that the solder strip is always on the main grid during the transmission process. The sheet is conveyed to the welding box, which is heated by infrared inside and has a heating plate underneath. During welding, the welding temperature is 180-220 degrees and the welding time is about 2S. Depending on the version, 9-12 battery cells are connected in series to form a battery string, such as Figure 1 As shown, components are formed in subsequent processes. It is not difficult to see from the above process that a suitable and stable welding temperature is an important guarantee for ensuring welding quality.

[0003] Existing heating structures such as Figure 2 As shown, in order to ensure the stability of the thermal field during welding, the welding process needs to be carried out in a nearly sealed environment. When the cell is transferred to the specified position, a large current (8-40A) is passed through the infrared lamp tube, making the instantaneous temperature of the silicon wafer surface reach 180-220 degrees, thus completing the welding.

[0004] However, the existing structure has the following defects:

[0005] a. The unevenness of the temperature field causes the actual welding temperature of each welding point to be inconsistent. While the overall welding tensile force meets the standard, there is still a risk of single-point cold welding or over-welding. The main reason is that in a nearly closed environment, heat will accumulate further. In order to ensure the consistency of heat before and after, it is necessary to add fans for heat dissipation. However, the introduction of heat dissipation will aggravate the unevenness of the local gas field, resulting in inconsistent effects at each pad point.

[0006] b. Topcon cells currently use laser-assisted sintering technology LECO. When LECO slurry is exposed to infrared light, efficiency attenuation will occur, which is mainly manifested in a decrease in Uoc and FF, with an efficiency loss of about 0.2%-0.5%. At the same time, the H passivation technology used by Topcon cells will cause H escape when the surface temperature exceeds 110-120 degrees even in the absence of light, resulting in a decrease in passivation effect and an efficiency loss of between 0.05%-0.2%. Utility Model Content

[0007] The purpose of the utility model is to design a heating device for a string welding machine of battery cells in order to solve the above problems.

[0008] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0009] A heating device for a stringer for a battery cell comprises a first heating element and a second heating element, wherein the first heating element and the second heating element are respectively used for heating and welding a first side surface and a second side surface of the battery cell, and the first heating element comprises at least one welding probe; a needle tip of a welding probe is used for welding between a battery cell and a welding strip, a distance between the needle tip of the welding probe and a pad point of the battery cell is greater than zero, and the needle tip of the welding probe forms a tip discharge, generating local high temperature and contacting with the welding strip.

[0010] The beneficial effects of the utility model are as follows: the heating device of the string welding machine does not need to heat the battery cell as a whole, thus avoiding the heat loss of H passivation. In the entire welding process, infrared heating is not used, and infrared attenuation caused by infrared can also be avoided; the heating device of the string welding machine adopts a local loss heating method, and in the continuous production process, a fan is not required for heat removal; the temperature of each point is controllable, which completely eliminates the influence of thermal field unevenness on the welding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a battery string in the background technology;

[0012] Figure 2 It is a schematic diagram of the heating structure of the prior art;

[0013] Figure 3 It is a structural schematic diagram of the first heating element in the heating device of the string welding machine for battery cells of the utility model;

[0014] Figure 4 It is a structural schematic diagram of a welding probe in a heating device of a string welding machine for battery cells of the utility model;

[0015] The corresponding figures are:

[0016] 1-wire, 2-rotating axis, 3-needle tip, 4-welding strip, 5-pad point, 6-battery cell main grid, 7-battery cell, 8-infrared heating lamp, 9-electric heating plate. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0020] In the description of the present utility model, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the utility model product is usually placed when in use, or are directions or positional relationships that are usually understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present utility model.

[0021] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The specific implementation of the utility model is described in detail below in conjunction with the accompanying drawings.

[0024] like Figure 3 , Figure 4 As shown, a heating device for a stringer for a battery cell 7 includes a first heating element and a second heating element, the first heating element and the second heating element are respectively used for heating and welding the first side and the second side of the battery cell 7, the first heating element includes at least one welding probe; a needle tip 3 of a welding probe is used for welding between a battery cell 7 and a welding strip 4, the distance between the needle tip 3 of the welding probe and the pad point 5 of the battery cell 7 is greater than zero, the needle tip 3 of the welding probe forms a tip discharge, generates local high temperature and contacts with the welding strip 4.

[0025] The welding probe comprises two conductive wires 1 and a metal needle. The first ends of the two conductive wires 1 are connected to the metal needle, and the second ends of the two conductive wires 1 are connected to a power source.

[0026] The distance between the tip 3 of the welding probe and the pad point 5 of the battery cell 7 is in the range of 3-10 mm.

[0027] The first heating element also includes at least one adjusting element, the first heating element includes at least one row of welding probe groups, a row of welding probe groups includes at least one welding probe, and an adjusting element is used to adjust the position of the needle tip 3 of a row of welding probe groups relative to the welding strip 4.

[0028] The adjusting member includes a rotating motor and a rotating shaft 2. The rotating shaft of the rotating motor is fixedly connected to the rotation center of the rotating shaft 2. The welding probe is fixedly mounted on the rotating shaft 2. The rotating motor is not shown in the figure.

[0029] The adjusting member comprises a linear moving member and a connecting rod. The moving action end of the linear moving member is fixedly connected to the connecting rod, and the welding probe is fixedly installed on the connecting rod.

[0030] The linear moving part is any one of a linear motor, an air cylinder and an oil cylinder.

[0031] The second heating element is an electric heating plate 9 , and the battery cell 7 is placed on the silicon wafer of the electric heating plate 9 .

[0032] The welding process of the heating device of the string welding machine used for the battery cell 7 of the utility model is as follows:

[0033] The adjustment part of this welding process is described using a rotating motor and a rotating shaft 2;

[0034] 1. The solder ribbon 4 soaked in solder is placed on the main grid 6 of the battery cell 7 and transported to the designated area along the conveyor belt;

[0035] 2. The welding probe row is pressed down as a whole, but does not touch the welding strip 4 and the pad point 5. The height of the needle tip 3 from the pad point 5 is about 3-10mm;

[0036] 3. The current passes through the conductive wire 1 and the tip 3 of the metal needle to form a tip discharge (corona discharge), generating local high temperature;

[0037] 4. Since the needle tip 3 may not be able to accurately align with the fine grid, during the tip discharge process, the rotating shaft 2 can be rotated to allow the needle tip 3 to point in a direction that can accurately align with the fine grid, ensuring that the local heat generated by the discharge of the needle tip 3 can contact the welding strip 4, thereby completing the welding process;

[0038] 5. The back pad uses the instantaneous heat conduction of the silicon wafer and the electric heating plate 9 to complete the welding. This welding process is completed simultaneously with the front welding process;

[0039] 6. After the welding is completed, the welded battery cell 7 is transported away to complete the next series of welding cycles.

[0040] The heating device of the string welding machine does not need to heat the battery cell 7 as a whole, thus avoiding the heat loss of H passivation. In the entire welding process, infrared heating is not used, and infrared attenuation caused by infrared can also be avoided; the heating device of the string welding machine adopts a local loss heating method, and in the continuous production process, a fan is not required for heat removal; the temperature of each point is controllable, which completely eliminates the influence of thermal field unevenness on the welding effect.

[0041] The technical solution of the present utility model is not limited to the above-mentioned specific embodiments, and all technical variations made according to the technical solution of the present utility model fall within the protection scope of the present utility model.

Claims

1. A heating device for a string welding machine for a battery cell, characterized in that: It includes a first heating element and a second heating element, which are respectively used for heating and welding the first side and the second side of the battery cell. The first heating element includes at least one welding probe. The needle tip of a welding probe is used for welding between a battery cell and a welding strip. The distance between the needle tip of the welding probe and the pad point of the battery cell is greater than zero. The needle tip of the welding probe forms a tip discharge, generates local high temperature and contacts with the welding strip.

2. The heating device for a stringer for a battery cell according to claim 1, characterized in that: The welding probe comprises two conductive wires and a metal needle. The first ends of the two conductive wires are both connected to the metal needle, and the second ends of the two conductive wires are connected to a power source.

3. The heating device for a stringer for a battery cell according to claim 1 or 2, characterized in that: The distance between the tip of the welding probe and the cell pad point ranges from 3 to 10 mm.

4. The heating device for a stringer for a battery cell according to claim 1, characterized in that: The first heating element also includes at least one adjusting element, the first heating element includes at least one row of welding probe groups, a row of welding probe groups includes at least one welding probe, and an adjusting element is used to adjust the position of the needle tip of a row of welding probe groups relative to the welding strip.

5. The heating device for a stringer for a battery cell according to claim 4, characterized in that: The adjusting member comprises a rotating motor and a rotating shaft. The rotating shaft of the rotating motor is fixedly connected to the rotating center of the rotating shaft. The welding probe is fixedly installed on the rotating shaft.

6. The heating device for a stringer for a battery cell according to claim 4, characterized in that: The adjusting member comprises a linear moving member and a connecting rod. The moving action end of the linear moving member is fixedly connected to the connecting rod, and the welding probe is fixedly installed on the connecting rod.

7. The heating device for a stringer for a battery cell according to claim 6, characterized in that: The linear moving part is any one of a linear motor, an air cylinder and an oil cylinder.

8. The heating device for a stringer for a battery cell according to claim 1, characterized in that: The second heating element is an electric heating plate, and the battery cell is placed on the silicon wafer of the electric heating plate.

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