Cutting battery piece and battery assembly

Abstract

The utility model is suitable for the technical field of battery cutting, and provides a cutting battery piece and a battery assembly. The cutting battery piece comprises a battery substrate, and a plurality of metal electrodes are arranged on the battery substrate; the metal electrode comprises a plurality of main grid lines which are parallel to one another, and each main grid line is provided with a disconnection structure. According to the utility model, each main grid line of the metal electrode in the battery substrate for cutting the battery piece is provided with a disconnection structure. A path for transmitting photon-generated carriers generated on the metal electrode to the cutting surface is cut off by the disconnection structure, the photon-generated carriers are difficult to transmit to the cutting surface of the cell, the photon-generated carriers cannot be compounded with defects and dangling bonds of the cutting surface, carrier compounding on the cutting surface of the cell is reduced, and the purposes of improving the cell efficiency and reducing the cell cost are achieved. And the cutting loss is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery cutting, and particularly relates to a cut solar cell and a battery module. Background Art

[0002] A solar cell is a basic unit in a photovoltaic module. It is a semiconductor device that can directly convert light energy into electrical energy. Solar cells are usually made of silicon (monocrystalline silicon or polycrystalline silicon), and convert sunlight into current through the photovoltaic effect. Multiple solar cells are connected in series or parallel to form a photovoltaic module for power generation applications.

[0003] Cutting a solar cell to form a multi-piece module composed of multiple cut solar cells can effectively reduce the current of a single cell and the resistance loss of the module, and improve the reliability and power generation efficiency of the battery module. However, after cutting the battery, damage will be caused to the battery surface, and defects and dangling bonds will be generated on the cut surface of the battery. The photo-generated carriers generated by the solar cell are easily transmitted to the cut surface of the battery through the back metalized grid lines or the silicon substrate of the battery, so that the photo-generated carriers will recombine with the defects and dangling bonds on the cut surface, resulting in a loss of battery efficiency. Summary of the Utility Model

[0004] The utility model provides a cut solar cell and a battery module, aiming at solving the technical problem that photo-generated carriers will recombine with defects and dangling bonds on the cut surface, resulting in a loss of battery efficiency.

[0005] The cut solar cell provided by the embodiment of the utility model is realized as follows. The cut solar cell includes a battery substrate, and a plurality of metal electrodes are arranged on the battery substrate;

[0006] Among them, the metal electrodes include: a plurality of main grid lines parallel to each other, and a disconnection structure is arranged on the main grid lines.

[0007] Furthermore, the cut solar cell has a cut surface, and a passivation protective film is deposited on the cut surface.

[0008] Furthermore, the battery substrate has a first surface and a second surface on which the metal electrodes are arranged. The first surface and the second surface are adjacent to the cut surface and are arranged opposite to each other;

[0009] A passivation protective film is deposited on the edge of the first surface close to the cut surface, and a passivation protective film is deposited on the edge of the second surface close to the cut surface.

[0010] Furthermore, the passivation protective film is a passivation protective film formed by solution deposition.

[0011] Further, the passivation protective film is a passivation protective film formed by deposition through soaking, dip coating, brushing, spraying, spin coating or scraping.

[0012] Further, the passivation protective film is any one or more of Nafion, PPV, PAA, P3HT, PMMA, and PSS.

[0013] Further, the thickness range of the passivation protective film is (0, 1000] nm.

[0014] Further, a plurality of metal pads are arranged on the main grid line, and the metal pads are arranged at intervals.

[0015] Further, the battery substrate is a PERC battery substrate, a TOPCon battery substrate, an HJT battery substrate or an IBC battery substrate.

[0016] An embodiment of the present invention further provides a battery assembly, which includes the cut battery chip as described above.

[0017] For the cut battery chip and the battery assembly provided by the embodiment of the present invention, a disconnection structure is arranged on each main grid line of the metal electrode in the battery substrate of the cut battery chip. The path for transmitting the photo-generated carriers generated on the metal electrode to the cut surface is blocked by the disconnection structure, and it is difficult for the photo-generated carriers to be transmitted to the cut surface of the battery. The photo-generated carriers cannot recombine with the defects and dangling bonds on the cut surface, reducing the carrier recombination on the cut surface of the battery, achieving the effects of improving the battery efficiency and reducing the cutting loss. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the first surface of the cut battery chip provided by the present invention;

[0019] Figure 2 is a schematic structural diagram of the cut surface of the cut battery chip provided by the present invention;

[0020] Figure 3 is a schematic structural diagram of the second surface of the cut battery chip provided by the present invention;

[0021] Figure 4 is a schematic structural diagram of the metal electrode of the cut battery chip provided by the present invention;

[0022] Main element symbol description: 10. Battery substrate; 11. Cut surface; 12. First surface; 13. Second surface; 20. Metal electrode; 21. Main grid line; 22. Sub-grid line; 30. Passivation protective film; 211. Metal pad; 212. Disconnection structure. Detailed Embodiments

[0023] In order to make the purpose, technical solutions and advantages of the present utility model more clear and understandable, the following further details the present utility model in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0024] Cutting the battery wafer into multiple sub-components can effectively reduce the current of a single battery and the resistance loss of the component, thereby improving the reliability and power generation efficiency of the battery component. However, the battery cutting process will cause damage to the battery surface, generating defects and dangling bonds on the cutting surface. The photo-generated carriers generated by the battery wafer are easily transmitted to the cutting surface through the back metalization grid lines or the silicon matrix of the battery, causing the photo-generated carriers to recombine with the defects and dangling bonds on the cutting surface, thereby resulting in a loss of battery efficiency.

[0025] Therefore, in order to solve the above technical problems, the present utility model provides a cutting battery wafer and a cutting battery.

[0026] Please refer to Figures 1 to 4 , an embodiment of the present utility model provides a cutting battery wafer, which can be applied to photovoltaic batteries. The cutting battery wafer provided by the embodiment of the present utility model includes a battery substrate 10, and a plurality of metal electrodes 20 are provided on the battery substrate 10. Among them, as Figure 4 shown, each metal electrode 20 includes: a plurality of mutually parallel main grid lines 21 and a plurality of mutually parallel sub-grid lines 22, the main grid lines 21 and the sub-grid lines 22 are perpendicular to each other, and a disconnection structure 212 is provided on each main grid line 21.

[0027] Specifically, each metal electrode 20 can be a positive metal electrode 20 or a negative metal electrode 20. Each metal electrode 20 includes a main grid line 21 and a sub-grid line 22.

[0028] In the cutting battery wafer of the embodiment of the present utility model, as Figure 4 shown, a disconnection structure 212 is provided on each main grid line 21 of the metal electrode 20 in its battery substrate 10. The path for transmitting the photo-generated carriers generated on the metal electrode 20 to the cutting surface 11 is blocked by the disconnection structure 212, making it difficult for the photo-generated carriers to be transmitted to the cutting surface 11 of the battery substrate 10. The photo-generated carriers cannot recombine with the defects and dangling bonds on the cutting surface 11, reducing the carrier recombination on the cutting surface 11 of the battery, achieving the effect of improving the battery efficiency of the cutting battery wafer and reducing the cutting loss. <00>

[0029] Further, for the disconnection structure 212 provided on each main grid line 21, in a possible implementation manner, the disconnection structure 212 may specifically be a disconnected isolation groove; or on each main grid line 21, a part of insulating material is provided to prevent carriers from passing through. It should be noted that the disconnection structure 212 is specifically a recoverable structure, that is, when the battery needs to be used normally, the disconnection structure 212 can be connected again so that the cut battery cell can be used normally.

[0030] In addition, for the specific setting manner of the disconnection structure 212, in a possible implementation manner, it can be achieved by laser scribing, that is, using a laser to scribe the disconnection structure 212 on each main grid line 21 to disconnect the recombination path of photo-generated carriers; it can also be achieved by chemical etching, that is, using a chemical etching method to form the disconnection structure 212 (etching groove) on the main grid line 21 to disconnect the recombination path of photo-generated carriers; it can also be achieved by insulation, that is, coating an insulating material on each main grid line 21 to form the disconnection structure 212 to disconnect the recombination path of photo-generated carriers; of course, it can also be physically disconnected on each main grid line 21 by using a mechanical cutting tool or arc fusing to form the disconnection structure 212 to disconnect the recombination path of photo-generated carriers. Of course, in other embodiments, the disconnection structure 212 can also be formed by other methods, which is not limited herein.

[0031] Further, in a possible implementation manner, as Figures 1 to 3 shown, the battery substrate 10 may specifically be one of a PERC battery substrate 10, a TOPCon battery substrate 10, an HJT battery substrate 10, or an IBC battery substrate 10. The specific setting manner of each metal electrode 20 can specifically form the metal electrode 20 on the battery substrate 10 by screen printing, inkjet printing, or electroplating.

[0032] Further, for the number of the main grid lines 21 and the sub-grid lines 22, as Figure 4 shown, in a possible implementation manner, in each metal electrode 20, there are at least 2 mutually parallel main grid lines 21 and 10 to 500 mutually parallel sub-grid lines 22, and the main grid lines 21 and the sub-grid lines 22 are perpendicular to each other. As Figure 4 shown, an example is given with 5 mutually parallel main grid lines 21 and 17 mutually parallel sub-grid lines 22 provided.

[0033] Moreover, further, as Figure 4As shown, a plurality of metal pads 211 are provided on the main grid line 21, and the metal pads 211 are arranged at intervals. Specifically, a plurality of metal pads 211 are provided on each main grid line 21, and the number of metal pads 211 is at least three, and the user can adjust according to the actual situation. In addition, for the specific position setting of the disconnection structure 212, the disconnection structure 212 can be set at any position on the main grid line 21, that is, it can be set between any two metal pads 211, or it can be set at any position at one end of any metal pad 211. And the number of disconnection structures 212 can be one or multiple, and the user can choose according to the actual situation.

[0034] Furthermore, in order to further reduce the loss during battery cutting, as Figures 1 to 4 shown, in a possible implementation manner, the cut battery chip has a cut surface 11, and a passivation protection film 30 is deposited on the cut surface 11.

[0035] Specifically, because when the cut surface 11 of the battery substrate 10 is naturally exposed to the air, the cut surface 11 will be naturally oxidized in the air, and an oxide layer will be formed on the cut section, which will increase the defects and dangling bonds on the surface of the cut surface 11. These defects and dangling bonds will become recombination centers of photo-generated carriers, reduce the lifetime of carriers, and thus reduce the battery efficiency.

[0036] Therefore, in the embodiment of the present invention, a passivation protection film 30 is deposited on the cut surface 11 of the battery substrate 10. By providing the passivation protection film 30, the cut surface 11 of the battery substrate 10 can be protected from contacting the air and causing natural oxidation, so that the number of dangling parts on the cut surface 11 is reduced, further reducing the carrier recombination of the cut surface 11, reducing the battery cutting loss, and improving the battery efficiency of the cut battery chip.

[0037] Furthermore, the battery substrate 10 has a first surface 12 and a second surface 13 provided with metal electrodes 20. The first surface 12 and the second surface 13 are adjacent to the cut surface 11, and the first surface 12 and the second surface 13 are arranged oppositely; a passivation protection film 30 is also deposited on the first surface 12 and the second surface 13, and a passivation protection film 30 is deposited on the edge of the first surface 12 close to the cut surface 11, and a passivation protection film 30 is deposited on the edge of the second surface 13 close to the cut surface 11.

[0038] Specifically, in addition to depositing the passivation protective film 30 on the battery substrate 10, the embodiment of the present invention also deposits the passivation protective film 30 on the first surface 12 and the second surface 13 of the battery substrate 10. Specifically, the passivation protective film 30 is also deposited on the edge portions of the first surface 12 and the second surface 13 close to the cutting surface 11. Therefore, the passivation protective film 30 is also deposited on the edge portions of the first surface 12 and the second surface 13 close to the cutting surface 11 to further protect the cutting surface 11 of the battery substrate 10 from contacting the air, achieving the effects of preventing oxidation of the cutting surface 11 of the battery substrate 10, reducing carrier recombination on the cutting surface 11, reducing battery cutting loss, and improving the battery efficiency of the cut battery wafers.

[0039] Furthermore, for the deposition method of the passivation protective film 30 described above, in a possible implementation manner, the passivation protective film 30 is a passivation protective film 30 formed by solution deposition. Specifically, the passivation protective film 30 is a passivation protective film 30 formed by soaking, dip coating, brushing, spraying, spin coating or scraping, that is, a passivation protective film 30 is deposited on the cutting surface 11 of the battery substrate 10, the first surface 12 of the battery substrate 10, and the second surface 13 of the battery substrate 10 by soaking, dip coating, brushing, spraying, spin coating or scraping the solution.

[0040] Therefore, by the method of depositing the passivation protective film 30 by solution, solution deposition can make a uniform passivation protective film 30 generated on the cutting surface 11, ensuring that the cutting surface 11 of the battery substrate 10 can be fully protected, reducing the generation of oxidation and defects; moreover, the solution deposition method can also form different types of passivation protective films 30 by using a variety of different chemical solutions, so as to achieve the effect of optimizing the battery performance; in addition, the solution deposition method can achieve the effect of precisely controlling the thickness of the protective film by adjusting the solution concentration and deposition time to meet different application requirements.

[0041] Specifically, for the materials used in solution deposition. The passivation protective film 30 can specifically be any one or more of Nafion (perfluorosulfonic acid resin, molecular formula: (C7HF13O5SC2F4)n), PPV (poly(phenylene vinylene) type, a kind of polymer, no fixed molecular formula), PAA (polyacrylic acid, chemical formula: (C3H4O2)n), P3HT (3-hexylthiophene, molecular formula: (C10H16S)n), PMMA (polymethyl methacrylate, molecular formula: (C10H16O4)n), PSS (polystyrene sulfonic acid, molecular formula: C8H8O3S). That is, the passivation protective film 30 can be deposited by soaking, dip coating, brushing, spraying, spin coating or scraping Nafion, PPV, PAA, P3HT, PMMA or PSS solution on the cutting surface 11, the first surface 12 and the second surface 13 of the battery substrate 10.

[0042] Furthermore, for the specific setting of the passivation protective film 30, in a possible implementation, the thickness range of the passivation protective film 30 is specifically (0, 1000] nm. Also, for the width of the passivation protective film 30 provided on the first surface 12 and the second surface 13 of the battery substrate 10, the thickness range is specifically (0, 100] μm, and the passivation protective film 30 provided on the first surface 12 and the second surface 13 is provided at the edge portions of the first surface 12 and the second surface 13 close to the cutting surface 11. The passivation protective film 30 on the cutting surface 11 of the battery substrate 10 should completely cover the cutting surface 11.

[0043] Specifically, by setting the thickness range of the passivation protective film 30 to be specifically (0, 1000] nm, the surface defects and dangling bonds on the cutting surface 11 can be effectively covered, preventing these defects and dangling bonds from becoming recombination centers of carriers, thereby reducing the recombination of photo-generated carriers and improving the battery efficiency and performance of the cut battery wafers. Moreover, the passivation protective film 30 within this thickness range can provide sufficient protection without having an adverse impact on other properties of the cut battery wafers due to being too thick.

[0044] Also, for the width range of the passivation protective film 30 on the first surface 12 and the second surface 13, it is specifically (0, 100] μm, enabling the passivation protective film 30 to effectively cover the cutting cross-section and its surrounding areas, achieving the effect of further reducing the influence of surface defects and dangling bonds. This can better prevent the recombination of photo-generated carriers and improve the battery efficiency and reliability of the cut battery wafers. The passivation protective film 30 within this width range can provide comprehensive protection while maintaining the feasibility and cost-effectiveness of the manufacturing process.

[0045] For example, in a possible implementation, the passivation protective film 30 can be deposited by chemical immersion. The material of the passivation protective film 30 is Nafion. When immersed, the concentration of the Nafion solution is 5 wt%, the immersion depth is 20 μm, the immersion time is 10 s, and after immersion, it is dried with nitrogen. The thickness of the passivation protective film 30 is 200 nm, and the width of the passivation protective film 30 on the surfaces of the first surface 12 and the second surface 13 is 20 μm. In addition, the passivation protective film 30 can also be deposited by dip coating. The material of the passivation protective film 30 is PSS, the thickness of the passivation protective film 30 is 500 nm, and the width of the passivation protective film 30 on the surfaces of the first surface 12 and the second surface 13 is 10 μm. Specific selection can be made according to the actual situation.

[0046] Therefore, in the embodiments of the present invention, the recombination of photo-generated carriers after the cutting of the battery wafers can be reduced in two aspects. On the one hand, during the cutting of the battery wafers, a disconnection structure 212 is provided on each main grid line 21 of the metal electrode 20 of the battery substrate 10, so that the path for transmitting the photo-generated carriers generated on the metal electrode 20 to the cutting surface 11 is blocked by the disconnection structure 212, making it difficult for the photo-generated carriers to be transmitted to the cutting surface 11 of the cut battery wafer. On the other hand, by depositing a passivation protective film 30 on the cutting surface 11, the cutting cross-section is protected from natural oxidation caused by contact with air, reducing the number of hanging bonds on the cutting surface 11. In this way, through the setting of the disconnection structure 212 on the main grid line 21 and the deposition of the passivation protective film 30 on the cutting surface 11, the photo-generated carriers generated by the battery substrate 10 cannot recombine with the defects and dangling bonds on the cutting surface 11, reducing the carrier recombination on the cutting surface 11 of the battery, achieving the effect of improving the battery efficiency of the cut battery wafer and reducing the cutting loss.

[0047] In addition, in the embodiments of the present invention, a battery module is also provided, which includes the above-mentioned cut battery wafer.

[0048] As shown in the following table, the following table is a comparison table of the battery efficiency of the cut battery wafers provided by the present invention with and without the disconnection structure and the passivation protective film. The following specifically compares the battery efficiency of the cut battery wafers with and without the disconnection structure 212 and the passivation protective film 30 provided. The cut battery wafers in the following table are cut from the battery wafers. The battery wafers and cut battery wafers in Scheme A do not have the disconnection structure 212 and the passivation protective film 30. The disconnection structure 212 is provided in both Scheme B and Scheme C, and Scheme D and Scheme E, and a passivation protective film 30 is deposited on the cutting surface 11 of the cut battery wafers. The difference is that in Scheme B and Scheme C, the passivation protective film 30 is deposited by soaking in a Nafion solution, and in Scheme D and Scheme E, the passivation protective film 30 is deposited by dip-coating with a PSS solution.

[0049]

[0050] Therefore, it can be seen from the table that by setting the disconnection structure 212, the cutting loss of the cut battery wafers can be effectively reduced, and further by depositing the passivation protective film 30, the cutting loss of the cut battery wafers can be further reduced.

[0051] In the description of this specification, the descriptions referring to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0052] In addition, the above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cut battery cell, characterized in that, It includes a battery substrate, on which a plurality of metal electrodes are provided; The cut battery cell has a cut surface, on which a passivation protective film is deposited; The battery substrate has a first surface and a second surface on which the metal electrodes are provided. The first surface and the second surface are adjacent to the cut surface and are oppositely arranged; A passivation protective film is deposited on the edge of the first surface close to the cut surface, and a passivation protective film is deposited on the edge of the second surface close to the cut surface; Among them, the metal electrode includes: a plurality of main grid lines parallel to each other, and a disconnection structure is provided on the main grid lines.

2. The cut battery cell according to claim 1, wherein The passivation protective film is a passivation protective film formed by solution deposition.

3. The cut battery cell according to claim 2, wherein The passivation protective film is a passivation protective film formed by deposition in a soaking, dipping, brushing, spraying, spin coating or scraping manner.

4. The cut battery cell according to claim 3, characterized in that, The passivation protective film is any one or more of Nafion, PPV, PAA, P3HT, PMMA, PSS.

5. The cut battery cell according to claim 1, wherein, The thickness of the passivation protective film is less than or equal to 1000 nm.

6. The cut battery cell according to claim 1, characterized in that, A plurality of metal pads are provided on the main grid lines, and the metal pads are arranged at intervals.

7. The cut battery cell according to claim 1, wherein, The battery substrate is a PERC battery substrate, a TOPCon battery substrate, an HJT battery substrate or an IBC battery substrate.

8. A battery assembly, characterized in that, It includes the cut battery cell according to any one of claims 1 to 7.

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