A novel battery cell interconnect strip and its preparation method

Abstract

This invention relates to a novel solar cell interconnect strip and its preparation method. When the novel interconnect strip is welded to the front of the solar cell, a reflective layer is provided on the light-facing surface, while the remaining surfaces are provided with a tin layer. By providing a reflective layer on the surface of the novel interconnect strip, light can be reflected, increasing the reflectivity of the interconnect strip surface and thus improving the light utilization rate of the photovoltaic panel; the overall resistance of the interconnect strip can also be reduced, thereby increasing the power of the photovoltaic panel; furthermore, the amount of tin used can be reduced, lowering costs and increasing production when tin supply is insufficient.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic panel technology, and particularly relates to a novel interconnect strip for solar cells and its preparation method. Background Technology

[0002] Currently, in the photovoltaic industry, photovoltaic panels use interconnecting strips to connect the solar cells together. Specifically, the interconnecting strips are welded to both sides of the solar cells through a welding process, allowing the current collected by the cells to be discharged. The main types of interconnecting strips currently used are: a. tin-plated round copper-based welding wire with diameters of 0.3, 0.26, and 0.24 mm; b. other shapes of interconnecting strips, such as rectangular welding wire and triangular welding wire.

[0003] However, existing interconnecting strips have the following drawbacks:

[0004] 1. Low reflectivity: The tin-plated interconnect strips have low light reflectivity, which affects the light utilization rate of the component.

[0005] 2. High cost: Tin is relatively rare and in short supply, resulting in a high price, which affects product output and increases costs.

[0006] 3. Electrical conductivity: Tin material itself has poor electrical conductivity, with a resistivity of 11.4 × 10^6. -8 . Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a novel battery cell interconnect strip and its preparation method.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a novel battery cell interconnection strip, wherein when the novel battery cell interconnection strip is welded to the front of the battery cell, a reflective layer is provided on the light-facing side of the surface, and a tin layer is provided on the remaining surfaces.

[0010] Furthermore, the novel battery cell interconnect strip includes a metal substrate, which is a circular metal wire, and the reflective layer is provided on the semi-circular surface away from the battery cell when the novel battery cell interconnect strip is welded to the front of the battery cell.

[0011] Furthermore, the reflective layer is an aluminum-plated layer, and the tin layer is a tin-plated layer.

[0012] Furthermore, the thickness of the reflective layer is 5μm to 10μm.

[0013] Furthermore, the reflective layer is located at one end of the circular metal wire and covers 1 / 4 of the outer circumference of the circular metal wire.

[0014] Secondly, the method for preparing the novel battery cell interconnect strip of the present invention includes:

[0015] S1. Surface treatment before plating: The metal substrate is subjected to alkali washing, acid washing, and water washing in sequence;

[0016] S2. Solvent treatment: Solvent treatment and drying of the metal substrate that has completed the pre-plating surface treatment;

[0017] S3. Hot-dip plating: Aluminum plating is performed on a portion of the surface of the metal substrate that has undergone flux plating treatment to form the aluminum plating layer; then, tin plating is performed on the remaining surface of the aluminum-plated metal substrate to form the tin plating layer;

[0018] S4. Post-plating treatment.

[0019] The method for preparing the novel battery cell interconnect strip of the present invention is a thermal spraying process, which includes: performing surface pretreatment and preheating on the metal substrate 1 in sequence, and then spraying a reflective layer on the light-facing side of the metal substrate when welding it to the front of the battery cell, and spraying a tin layer on the remaining surfaces.

[0020] The beneficial effects of this invention are:

[0021] 1. The reflective layer (aluminum plating layer) on the surface of the new type of battery cell interconnect strip can reflect light, increase the reflectivity of the interconnect strip surface, and thus improve the light utilization rate of the photovoltaic panel.

[0022] 2. By setting a reflective layer (aluminum plating) on ​​the surface of the new type of solar cell interconnect strip, not only can the overall resistance of the interconnect strip be reduced, thereby increasing the power of the photovoltaic panel; it can also reduce the amount of tin used, reduce costs, and increase production when tin supply is insufficient.

[0023] 3. By obtaining a thinner reflective layer (aluminum plating) on ​​the surface of the metal substrate, the requirements of subsequent lamination processes are met, avoiding the problem of the solar cells being crushed during the lamination process due to excessively thick plating. This method is applicable to the existing photovoltaic panel lamination process and requires no adjustment. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the novel battery cell interconnection strip described in this invention;

[0025] Figure 2 yes Figure 1 Cross-sectional view along AA;

[0026] Figure 3 This is a schematic diagram of the welding of the novel battery cell interconnect strip described in this invention;

[0027] Figure 4 yes Figure 3 Cross-sectional view of the structure along BB;

[0028] Figure 5 This is a schematic flowchart of the preparation method of the novel battery cell interconnect strip described in this invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] like Figure 1-4 As shown, when the novel battery cell interconnect strip of the present invention is welded to the front of the battery cell 4, a reflective layer 2 is provided on the surface facing the light (as shown in the figure, the surface facing upwards of the novel battery cell interconnect strip), and a tin layer 3 is provided on the remaining surfaces. Specifically, the novel battery cell interconnect strip includes a metal substrate 1, which is a circular metal wire, preferably a circular copper wire. The reflective layer 2 is provided on the semi-circular arc surface of the metal substrate 1 away from the battery cell (i.e., the upper half of the arc surface in the figure) when the novel battery cell interconnect strip is welded to the front of the battery cell 4. The reflective layer 2 is an aluminum-plated layer with a thickness of 5μm to 10μm, mainly serving to reflect light and resist oxidation. The tin layer 3 is a tin-plated layer.

[0031] The method for preparing the novel battery cell interconnect strip described in this invention, as follows: Figure 5 As shown, it specifically includes:

[0032] Step S1. Surface treatment before plating: The metal substrate 1 is subjected to alkali washing, acid washing, and water washing in sequence.

[0033] Step S2. Fluxing treatment: The metal substrate 1 that has completed the pre-plating surface treatment is subjected to solvent treatment and drying; the solvent treatment is flux treatment, and the flux used is KF aqueous solution flux, which greatly improves the activity of the copper surface and obtains a good copper-aluminum bonding interface.

[0034] Step S3. Hot-dip plating: The metal substrate 1, after undergoing fluxing treatment, is partially aluminum-plated to form the aluminum layer. The thickness of the aluminum layer can be controlled to be 5μm to 10μm by controlling the hot-dip plating time and temperature. Then, the remaining surface of the aluminum-plated metal substrate 1 is tin-plated to form the tin layer. By plating aluminum first and then tin, the problem of secondary melting of the tin layer that is tin-plated first and then aluminum-plated can be avoided, ensuring the quality of the aluminum and tin layers formed on the surface of the metal substrate 1 after hot-dip plating, thereby improving the performance of the new battery cell interconnect strip. Specifically, before partially aluminum-plating the metal substrate 1, a protective film (such as a PET high-temperature resistant protective film) is applied to the surface of the metal substrate 1 that does not need aluminum plating. Before tin-plating the remaining surface of the metal substrate 1, the protective film on this surface is removed, and then a protective film is applied to the surface of the aluminum layer. In this way, the boundary between the aluminum and tin layers formed on the surface of the metal substrate 1 can be accurately controlled, and the influence of the tin plating process on the aluminum layer can be further reduced, thereby improving product quality.

[0035] Step S4. Post-plating treatment, which includes the removal of the coating on the surface of the aluminum plating layer.

[0036] The aforementioned pre-plating surface treatment, fluxing treatment, and post-plating treatment are all existing technologies, and the specific operations will not be described in detail here.

[0037] Of course, the novel battery cell interconnect strip described in this invention can also be manufactured using existing thermal spraying processes. The specific steps include: pretreatment of the surface of the metal substrate 1 (including purification and roughening), preheating and spraying (spraying a reflective layer on the light-facing side of the metal substrate 1 when welding it to the front of the battery cell, and spraying a tin layer on the remaining surfaces). The specific operations will not be described in detail here.

[0038] This invention, by setting a reflective layer 2 (aluminum plating) on ​​the surface of a novel solar cell interconnect strip, compared with existing interconnect strips, has several advantages. First, the reflective layer 2 can reflect light, increasing the reflectivity of the interconnect strip surface and thus improving the light utilization rate of the photovoltaic panel. Second, it can reduce the overall resistance of the interconnect strip, thereby increasing the power of the photovoltaic panel. Third, it can reduce the amount of tin used, lowering costs and increasing production when tin supply is insufficient. Moreover, a reflective layer 2 thinner than the tin plating layer (usually 15μm) can be obtained on the surface of the metal substrate 1, meeting the requirements of subsequent lamination processes and avoiding the problem of the solar cells being crushed during lamination due to excessively thick plating. It is applicable to the existing photovoltaic panel lamination process without adjustment.

[0039] Preferably, for example Figure 1-4As shown, the reflective layer 2 (aluminum-plated layer) of the novel battery cell interconnect strip of the present invention is located at one end of the circular metal wire and covers 1 / 4 of the outer surface of the circular metal wire. In this way, it can ensure that the interconnect strip can be welded to conduct battery cells, ensuring the weld is firm, and can also maximize the reflective surface, further increasing the reflectivity, thereby further improving the light utilization rate of the photovoltaic panel, and can also reduce the amount of tin used, thus reducing costs.

[0040] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A novel battery cell interconnection strip, characterized in that, It includes a metal substrate (1), which is a circular metal wire. When the interconnecting strip of the new battery cell is welded to the front of the battery cell (4), a reflective layer (2) is provided on the semi-circular arc surface away from the battery cell, and a tin layer (3) is provided on the other surface. The reflective layer (2) is an aluminum-plated layer with a thickness of 5μm or 10μm, and the tin layer (3) is a tin-plated layer. The reflective layer (2) is located at one end of the circular metal wire and covers 1 / 4 of the outer surface of the circular metal wire.

2. A method for preparing the novel battery cell interconnect strip as described in claim 1, characterized in that, include: S1. Surface treatment before plating: The metal substrate (1) is subjected to alkali washing, acid washing and water washing in sequence; S2. Flushing treatment: Solvent treatment and drying of the metal substrate (1) that has completed the pre-plating surface treatment; S3. Hot-dip plating: Aluminum plating is performed on a portion of the metal substrate (1) after the fluxing treatment to form the aluminum plating layer; then tin plating is performed on the remaining surface of the aluminum-plated metal substrate (1) to form the tin plating layer. S4. Post-plating treatment.

3. A method for preparing the novel battery cell interconnect strip as described in claim 1, characterized in that, The method is a thermal spraying process, which includes: performing surface pretreatment and preheating on the metal substrate (1) in sequence, and then spraying a reflective layer on the light-facing side of the metal substrate (1) when welding it to the front of the battery cell, and spraying a tin layer on the remaining surface.

Images