BC battery string welding method and device

Abstract

The invention discloses a BC battery string welding method and device. The BC battery string welding method comprises the following steps that a welding strip fixing agent is preset on a battery piece; heating the battery piece to melt the welding strip fixing agent on the battery piece; enabling the heated battery piece to quickly contact with the welding strip, and fixing the welding strip on the battery piece through the curing of the welding strip fixing agent, so as to complete the welding or fixing between the battery piece and the welding strip; the solder strip is heated at normal temperature or independently, and the temperature of the solder strip is lower than that of the cell; the mode that the battery piece is independently heated till the welding strip fixing agent is molten and then makes contact with the welding strip to achieve welding or fixing is adopted instead of an existing mode that the battery piece and the welding strip are synchronously heated after being pressed, and therefore the problem that in the synchronous heating mode, the shrinkage amount is different due to the difference of base material thermal expansion coefficients, and consequently the battery piece is bent is solved; bending of the battery piece is effectively reduced or even avoided, and the overall quality and effect after the battery piece and the welding strip are welded are greatly guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cells, and in particular to a BC battery string welding method and device. Background Art

[0002] BC (Back Contact) battery cell is a back contact battery cell, which is a technology that sets both positive and negative metal contacts on the back of the battery cell.

[0003] When the BC cell is welded in a string, the welding tape is located on the back of the cell. In the prior art, the cell and the solder tape are usually pressed and heated to connect the solder tape to the cell. Since the welding tape substrate is usually copper, the battery cell substrate is usually silicon, and the thermal expansion coefficient of copper is much larger than that of silicon. After cooling, the shrinkage of the welding tape is greater than the shrinkage of the battery cell, causing the welding tape to pull and bend the battery cell. Summary of the invention

[0004] To solve the above problems, the present invention provides a BC cell string welding method and device with a reasonable structure, thereby effectively reducing or even avoiding the bending of the cell, greatly ensuring the overall quality and effect after welding the cell and the welding tape.

[0005] The technical solution adopted by the present invention is as follows: A BC battery string welding method comprises the following steps: Heating the battery cell with a preset soldering agent to melt the soldering agent on the battery cell; The heated battery cell is quickly contacted with the welding tape, and the welding tape is fixed to the battery cell by curing the welding tape fixing agent to complete the welding or fixing between the battery cell and the welding tape; the welding tape is heated at room temperature or separately, and the welding tape temperature is lower than the battery cell temperature.

[0006] As a further improvement of the above technical solution: Use heat source to heat the battery cells individually; After the battery cell is heated, the heat source is separated from the battery cell or the heat source is turned off; or, after the heated battery cell is in contact with the welding strip for a preset time, the heat source is separated from the battery cell or the heat source is turned off.

[0007] The welding ribbon and the battery cell are heated by a heat source respectively; After heating, the battery cell and the welding tape are respectively contacted with heat sources or one of them with heat sources. After contacting the preset time, the heat source or the heat source will be turned off; or, after heating, the battery cell and the welding tape are respectively contacted with heat sources and then soldered or cured.

[0008] After the battery cell is heated by the heat source, the battery cell is driven by the driving force to move toward and contact the welding strip, and at the same time, the heated battery cell is separated from the heat source.

[0009] After the battery cell is heated by the heat source, the heat source is turned off, and the welding strip is driven by the driving force to move toward and contact the battery cell, or the battery cell is driven by the driving force to move toward and contact the welding strip.

[0010] After the battery is heated by a heat source, the welding belt is driven by the driving force to move and contact towards the battery cell, or the heat source moves and contact towards the welding belt with the driving force to move and contact with the welding belt; after the contact preset time, the heat source is separated from the battery cell or the heat source is closed.

[0011] The heat source includes, but is not limited to, one or more of a heating rod, an infrared lamp, an LED lamp, and electromagnetic heating.

[0012] The battery cell is located above the soldering strip, and a soldering strip fixing agent is preset on the bottom surface of the battery cell; the battery cell is clamped or adsorbed on the upper battery cell platform, and the soldering strip is constrained and supported on the lower soldering strip platform.

[0013] The restraining support method of the welding tape platform for the welding tape includes active restraint support or passive restraint support. The active restraint support includes but is not limited to one of adsorption and clamping. The passive restraint support includes stickiness caused by friction between the welding tape and the surface of the welding tape platform.

[0014] The battery cell is located below the soldering tape, and a soldering tape fixing agent is preset on the top surface of the battery cell; the battery cell is clamped or adsorbed on the lower battery cell platform, and the soldering tape is clamped or adsorbed on the upper soldering tape platform.

[0015] A heat dissipation platform is provided on the surface of the soldering ribbon platform facing away from the soldering ribbon, or a heat dissipation system is built into the soldering ribbon platform.

[0016] A heat-insulating material is applied on the side of the welding strip facing away from the battery cell.

[0017] The soldering tape fixing agent is one or more of solder paste, conductive adhesive and conductive adhesive film.

[0018] A BC battery string welding device includes a heat source, a soldering ribbon platform, and a battery cell platform. The heat source heats the battery cells on the battery cell platform individually to cause the soldering ribbon fixing agent on the battery cells to melt, and the soldering ribbon platform constrains and supports the soldering ribbon. The device also includes a driving force, which moves the heated battery cells quickly toward the soldering ribbon and makes them contact, or moves the soldering ribbon quickly toward the heated battery cells and makes them contact, or moves the soldering ribbon and the heated battery cells quickly toward each other at the same time to make them contact.

[0019] As a further improvement of the above technical solution: The battery cell and the welding strip are heated by heat sources respectively.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention replaces the existing method of simultaneously heating the battery cell and the welding strip after pressing the battery cell and the welding strip together, by heating the battery cell individually until the welding strip fixer is melted and then contacting the battery cell with the welding strip to achieve welding or fixing. It solves the problem of battery cell bending caused by different shrinkage amounts due to differences in thermal expansion coefficients of the substrates in the simultaneous heating method, effectively reduces or even avoids battery cell bending, and greatly ensures the overall quality and effect of the battery cell and the welding strip after welding.

[0021] The present invention also includes the following advantages: By heating the battery cell individually with a heat source and then having the heated battery cell contact the welding ribbon individually, or by having the heat source and the battery cell contact the welding ribbon synchronously for a preset time, the hysteresis of heat conduction is cleverly utilized. During the contact process with the welding ribbon, the temperature of the welding ribbon is lower than the temperature of the battery cell, so that there is a temperature difference between the battery cell and the welding ribbon. In other words, the heating conditions between the battery cell and the welding ribbon are different, thereby compensating for the bending of the battery cell caused by different shrinkage amounts due to different thermal expansion coefficients. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the state where the battery cell of the present invention is located below the welding strip.

[0023] Figure 2 It is a schematic diagram of the state where the battery cell of the present invention is located above the welding strip.

[0024] Among them: 10, welding ribbon platform; 20, welding ribbon; 30, battery cell; 40, battery cell platform; 50, heat source. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0026] A BC battery string welding method of this embodiment includes the following steps: Step 1: heating the battery cell 30 with a preset soldering tape fixing agent to melt the soldering tape fixing agent on the battery cell 30; The second step: quickly contact the heated battery cell 30 with the welding tape 20 , fix the welding tape 20 on the battery cell 30 by curing the welding tape fixing agent , and complete the welding or fixing between the battery cell 30 and the welding tape 20 ; the welding tape 20 is heated at room temperature or separately, and the temperature of the welding tape 20 is lower than the temperature of the battery cell 30 .

[0027] In this embodiment, by heating the battery cell 30 to melt the welding tape fixing agent and then contacting the welding tape 20 to achieve welding or fixing, the existing battery cell and the welding tape are replaced by the synchronous heating method, thereby solving the problem of cell bending caused by the difference in the thermal expansion coefficient of the substrate in the synchronous heating method due to the different shrinkage amount caused by the difference in the thermal expansion coefficient of the substrate.

[0028] In this embodiment, the battery cell 30 is heated separately, and then contacted quickly with the welding tape 20 to achieve fixing or welding. During the entire process, the temperature of the welding tape 20 is lower than the temperature of the battery cell 30, effectively reducing the difference in shrinkage caused by the coefficient of thermal expansion between the welding tape 20 and the battery cell 30.

[0029] In this embodiment, when the welding tape 20 is at room temperature, the welding tape 20 is heated separately to the welding tape fixing agent and then the welding tape 20 is in rapid contact with the welding tape 20 in the normal temperature state, and the welding tape 20 is fixed to the battery cell 30 by curing the welding tape fixing agent.

[0030] In actual use, the soldering tape 20 at room temperature can be reliably fixed to the separately heated battery cell 30 .

[0031] In this embodiment, the soldering ribbon 20 can be heated separately according to actual needs to meet different process requirements, such as heating the soldering ribbon 20 to slow down the curing speed after contacting the heated battery cell 30 to improve the curing quality of the battery cell 30 and the soldering ribbon 20. Of course, considering the difference in thermal expansion coefficients between the soldering ribbon 20 and the battery cell 30, when heating the soldering ribbon 20, the heating temperature of the soldering ribbon 20 needs to be lower than the heating temperature of the battery cell 30.

[0032] The battery cell 30 is heated separately by using a heat source 50 . After heating the battery cell 30 , the heat source 50 is separated from the battery cell 30 or the heat source is closed ; thus, the heat source 50 only acts on the battery cell 30 , reducing or even avoiding the effect on the welding tape 20 .

[0033] In one of the embodiments, after the battery cell 30 is heated by the heat source 50 , the battery cell 30 is driven to move and contact toward the welding belt 20 by driving force, while the heated battery cell 30 is separated from the heat source 50 ; thereby achieving separate heating of the battery cell 30 by the heat source 50 .

[0034] In another embodiment, after the battery cell 30 is heated by the heat source 50 , the heat source 50 is closed, and the welding belt 20 is driven by the driving force to move and contact towards the battery cell 30 , or the battery cell 30 is driven by the driving force to move and contact towards the welding belt 20 ; thereby achieving separate heating of the battery cell 30 by the heat source 50 .

[0035] In another embodiment, after the battery cell 30 is heated by the heat source 50 , the heat source 50 and the battery cell 30 are in contact with the welding ribbon 20 for a preset time, and then the heat source 50 is separated from the battery cell 30 or the heat source 50 is turned off.

[0036] In this embodiment, the heat source 50 is in contact with the soldering ribbon 20 along with the battery cell 30 , so as to maintain the temperature of the soldering ribbon fixing agent, thereby facilitating reliable fixing to the soldering ribbon 20 .

[0037] Of course, in actual operation, the preset time is closely related to factors such as the material and the heating temperature of the heat source 50 , and the preset time can be determined based on actual experiments and actual needs.

[0038] In this embodiment, the heat source 50 is in contact with the welding belt 20 with the battery cell 30 . It can be driven by the driving force to move towards the welding belt 20 . It can be driven by the driving force to move towards the battery cell 30 and the heat source 50 . It can also be driven by the driving force to move towards the battery cell 30 and the heat source 50 . It can be driven by the driving force to move towards the opposite direction, so as to realize the contact between the welding belt 20 and the battery cell 30 .

[0039] In this embodiment, after the heat source 50 and the battery cell 30 are in contact with the welding ribbon 20 for a preset time, the heat source 50 can be separated from the battery cell 30 by an external driving force, or the heat source 50 can be turned off.

[0040] Of course, in actual operation, in addition to using the heat source 50 to heat the battery cell 30 separately, the welding tape 20 and the battery cell 30 may also be heated by the heat source 50 respectively, so that the heating temperature of the welding tape 20 is lower than the temperature of the battery cell 30 .

[0041] In one embodiment, after the welding tape 20 and the battery cell 30 are respectively heated, the battery cell 30 and the welding tape 20 contact each other with a heat source 50 or one of the heat source 50 and turn off the heat source 50 or the heat source 50 after contacting the preset time.

[0042] In another embodiment, after the soldering ribbon 20 and the battery cell 30 are heated respectively, the battery cell 30 and the soldering ribbon 20 are separated from the heat source 50 and then contact each other for soldering or curing.

[0043] The heat source 50 includes, but is not limited to, one or more of a heating rod, an infrared lamp, an LED lamp, and electromagnetic heating; any one of the heat sources 50 can achieve rapid heating of the battery cell 30 or the soldering ribbon 20 .

[0044] In such Figure 1 In the embodiment shown, the battery cell 30 is located below the welding tape 20 , and the top surface of the battery cell 30 is pre-equipped with a welding tape fixing agent; the battery cell 30 is clamped or adsorbed on the lower battery cell platform 40 , and the welding tape 20 is clamped or adsorbed on the upper welding tape platform 10 .

[0045] In this embodiment, a negative pressure hole connected to an external air source can be arranged on the battery cell platform 40 to achieve adsorption and fixation of the battery cell 30. Of course, a clamping member can also be provided on the battery cell platform 40 to clamp the battery cell 30 and fix it. A heating rod, infrared lamp, LED lamp, electromagnetic or other heat source 50 can also be arranged inside the battery cell platform 40 to achieve individual rapid heating of the battery cell 30.

[0046] In this embodiment, a negative pressure hole communicating with an external air source can be opened on the welding tape platform 10 to realize adsorption and fixing of the welding tape 20, or a clamping member can be provided on the welding tape platform 10, and the clamping member can clamp the welding tape 20 to achieve fixing.

[0047] In actual use, after the heat source 50 heats the battery cell 30 on the battery cell platform 40, the heat source 50 is turned off, and the battery cell 30 can be driven upward along with the battery cell platform 40 by an external driving force to quickly contact with the soldering tape 20 on the bottom surface of the upper soldering tape platform 10; or, the soldering tape 20 can be driven downward along with the soldering tape platform 10 by an external driving force to quickly contact with the battery cell 30 on the top surface of the lower battery cell platform 40; thereby, the soldering tape curing agent can realize the fixation and welding of the soldering tape 20 on the battery cell 30.

[0048] In such Figure 2 In the embodiment shown, the battery cell 30 is located above the welding tape 20 , and the bottom surface of the battery cell 30 is pre-equipped with a welding tape fixing agent; the battery cell 30 is clamped or adsorbed on the upper battery cell platform 40 , and the welding tape 20 is restrained and supported on the lower welding tape platform 10 .

[0049] In this embodiment, a negative pressure hole connected to an external air source can be arranged on the battery cell platform 40 to achieve adsorption and fixation of the battery cell 30 on the bottom surface. Of course, a clamping member can also be provided on the battery cell platform 40 to clamp and fix the battery cell 30. A heating rod, infrared lamp, LED lamp, electromagnetic or other heat source 50 can also be arranged inside the battery cell platform 40 to achieve individual rapid heating of the battery cell 30.

[0050] In actual use, after the heat source 50 heats the battery cell 30 on the battery cell platform 40, the heat source 50 is turned off, and the battery cell 30 can be driven downward along with the battery cell platform 40 by an external driving force to quickly contact with the soldering tape 20 on the top surface of the soldering tape platform 10 below; or, the soldering tape 20 can be driven upward along with the soldering tape platform 10 by an external driving force to quickly contact with the battery cell 30 on the bottom surface of the battery cell platform 40 above; thereby, the soldering tape curing agent can realize the fixation and welding of the soldering tape 20 on the battery cell 30.

[0051] In this embodiment, the restraining support method of the welding tape platform 10 for the welding tape 20 includes active restraint support or passive restraint support. The active restraint support includes but is not limited to one of adsorption and clamping. The passive restraint support includes stickiness caused by friction between the welding tape 20 and the surface of the welding tape platform 10.

[0052] In one of the embodiments, a negative pressure hole communicating with an external air source can be opened on the welding tape platform 10 to achieve adsorption and fixation of the welding tape 20, or a clamping member can be provided on the welding tape platform 10, such as a pair of clamping members symmetrically arranged at both ends of each welding tape 20, and each welding tape 20 is clamped and fixed by the clamping member.

[0053] In another embodiment, the surface of the welding tape platform 10 supporting the welding tape 20 is arranged as a soft silicone plate, and the welding tape 20 placed on the soft silicone plate produces stickiness under the action of friction, similar to the welding tape 20 being fixed to the welding tape platform 10 .

[0054] A heat dissipation platform is provided on the surface of the soldering ribbon platform 10 facing away from the soldering ribbon 20 , or the soldering ribbon platform 10 has a built-in heat dissipation system; when the process requires, the curing speed of the soldering ribbon curing agent can be increased through heat dissipation.

[0055] In one embodiment, a heat insulating material is laid on the side of the solder strip 20 facing away from the battery cell. The laying of the heat insulating material can slow down and reduce heat dissipation.

[0056] The soldering tape fixing agent is one or more of solder paste, conductive adhesive and conductive adhesive film.

[0057] In this embodiment, solder paste is pre-printed on the battery cell 30 . As the battery cell 30 is heated, the solder paste on the battery cell 30 melts. After the solder belt 20 comes into contact with the battery cell 30 , the solder paste cools and solidifies, and the battery cell 30 and the solder belt 20 are fixed together to form a solder joint.

[0058] In this embodiment, the conductive adhesive and the conductive adhesive film are pre-coated on the battery cell 30 . As the battery cell 30 is heated, the conductive adhesive and the conductive adhesive film on the battery cell 30 trigger the reaction; after the welding tape 20 comes into contact with the battery cell 30 , the conductive adhesive and the conductive adhesive film are solidified, and the battery cell 30 and the welding tape 20 are fixed, and an electrical path is formed between the battery cell 30 and the welding tape 20 .

[0059] The present embodiment further proposes a BC battery string welding device, comprising a heat source 50, a welding ribbon platform 10, and a battery cell platform 40. The heat source 50 heats the battery cell 30 on the battery cell platform 40 individually to cause the welding ribbon fixing agent on the battery cell 30 to melt, and the welding ribbon platform 10 constrains and supports the welding ribbon 20; it also includes a driving power, the driving power quickly moves the heated battery cell 30 toward the welding ribbon 20 and contacts it, or the driving power quickly moves the welding ribbon 20 toward the heated battery cell 30 and contacts it, or the driving power quickly moves the welding ribbon 20 and the heated battery cell 30 toward each other at the same time to make them contact.

[0060] In one of the embodiments, the cell 30 and the welding tape 20 are heated by the heat source 50 respectively; that is, the welding tape 20 can also be heated separately according to actual process requirements, and the heating temperature of the welding tape 20 is lower than the heating temperature of the battery 30 to reduce the difference in shrinkage caused by the coefficient of thermal expansion between the welding tape 20 and the battery 30 .

[0061] The BC battery string welding device in this embodiment adopts a BC battery string welding method. By heating the battery cell 30 separately, the solder strip fixing agent on the battery cell 30 is melted or dissolved. Combined with the rapid contact between the battery cell 30 and the solder strip 20, the fixation and welding between the battery cell 30 and the solder strip 20 are achieved through the solder strip fixing agent, and the bending phenomenon caused by the difference in shrinkage caused by the thermal expansion coefficient of the material between the battery cell 30 and the solder strip 20 is effectively reduced or even avoided.

[0062] The present invention effectively reduces or even avoids the bending of the battery cell, and greatly ensures the overall quality and effect of the battery cell and the welding strip after welding.

[0063] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0064] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A BC battery string welding method, characterized in that: The steps include: Heating the battery cell with a preset soldering agent to melt the soldering agent on the battery cell; The heated battery cell is quickly brought into contact with the soldering tape, and the soldering tape is fixed to the battery cell by curing the soldering tape fixing agent, thereby completing the welding or fixing between the battery cell and the soldering tape; the soldering tape is at room temperature or heated separately, and the soldering tape temperature is lower than the battery cell temperature.

2. A BC battery string welding method as claimed in claim 1, characterized in that: Use heat source to heat the battery cells individually; After the battery cell is heated, the heat source is separated from the battery cell or the heat source is turned off; or, after the heated battery cell is in contact with the welding strip for a preset time, the heat source is separated from the battery cell or the heat source is turned off.

3. A BC battery string welding method as claimed in claim 1, characterized in that: The welding ribbon and the battery cell are heated by a heat source respectively; After heating, the battery cell and the soldering ribbon are respectively brought into contact with the heat source or one of them is brought into contact with each other, and after a preset contact time, the heat source is turned off or the heat source is removed; or, after heating, the battery cell and the soldering ribbon are respectively separated from the heat source and then contacted with each other for welding or curing.

4. A BC battery string welding method as claimed in claim 2 or 3, characterized in that: After the battery cell is heated by the heat source, the battery cell is driven by the driving force to move toward and contact the welding strip, and at the same time, the heated battery cell is separated from the heat source.

5. A BC battery string welding method as claimed in claim 2 or 3, characterized in that: After the battery cell is heated by the heat source, the heat source is turned off, and the welding strip is driven by the driving force to move toward and contact the battery cell, or the battery cell is driven by the driving force to move toward and contact the welding strip.

6. A BC battery string welding method as claimed in claim 2 or 3, characterized in that: After the battery cell is heated by the heat source, the welding strip is driven by the driving force to move toward and contact the battery cell, or the heat source is driven by the driving force to move toward and contact the welding strip along with the battery cell; after a preset contact time, the heat source is separated from the battery cell or the heat source is turned off.

7. A BC battery string welding method as claimed in claim 2 or 3, characterized in that: The heat source includes, but is not limited to, one or more of a heating rod, an infrared lamp, an LED lamp, and electromagnetic heating.

8. A BC battery string welding method as claimed in claim 1, characterized in that: The battery cell is located above the soldering strip, and a soldering strip fixing agent is preset on the bottom surface of the battery cell; the battery cell is clamped or adsorbed on the upper battery cell platform, and the soldering strip is constrained and supported on the lower soldering strip platform.

9. A BC battery string welding method as claimed in claim 8, characterized in that: The restraint support mode of the soldering strip platform for the soldering strip includes active restraint support or passive restraint support. The active restraint support includes but is not limited to one of adsorption and clamping. The passive restraint support includes the viscosity caused by the friction between the soldering strip and the surface of the soldering strip platform.

10. A BC battery string welding method as claimed in claim 1, characterized in that: The battery cell is located below the soldering tape, and a soldering tape fixing agent is preset on the top surface of the battery cell; the battery cell is clamped or adsorbed on the lower battery cell platform, and the soldering tape is clamped or adsorbed on the upper soldering tape platform.

11. A BC battery string welding method as claimed in claim 8 or 10, characterized in that: A heat dissipation platform is provided on the surface of the soldering ribbon platform facing away from the soldering ribbon, or a heat dissipation system is built into the soldering ribbon platform.

12. A BC battery string welding method as claimed in claim 1, characterized in that: A heat-insulating material is applied on the side of the welding strip facing away from the battery cell.

13. A BC battery string welding method as claimed in claim 1, characterized in that: The soldering tape fixing agent is one or more of solder paste, conductive adhesive and conductive adhesive film.

14. A BC battery string welding device, characterized in that: The invention comprises a heat source, a soldering ribbon platform and a battery cell platform, wherein the heat source heats the battery cells on the battery cell platform individually to melt the soldering ribbon fixing agent on the battery cells, and the soldering ribbon platform restrains and supports the soldering ribbon; the invention also comprises a driving force, wherein the driving force moves the heated battery cells rapidly toward and contacts the soldering ribbon, or the driving force moves the soldering ribbon rapidly toward and contacts the heated battery cells, or the driving force moves the soldering ribbon and the heated battery cells rapidly toward each other at the same time to contact them.

15. A BC battery string welding device as claimed in claim 14, characterized in that: The battery cell and the welding strip are heated by heat sources respectively.

Images