Electrode structure of back contact battery
By making P and N regions arranged in parallel spaces on the back of the BC battery, abolishing the main gate and using only fine gate lines, the problems of complex and high cost of the existing BC battery electrode structure are solved, and more efficient battery performance is achieved.
Patent Information
- Application Number
- CN202421782180.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-26
AI Technical Summary
The interdigital arrangement electrodes of existing BC batteries have complex structures and high production costs.
Directly make straight strips P and N regions arranged in parallel space on the back of the back contact battery, cancel the main gate, and make thin gate lines on the P and N regions.
The production process is simplified, metal composite is reduced, efficiency is improved, the opening pressure is increased by 2mV, FF is increased by 0.5, and efficiency is increased by more than 0.2%.
Smart Images
Figure CN222852584U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solar cells, in particular to a main grid-free electrode structure of a BC cell. Background Art
[0002] In solar cell technology, BC cell refers to the back contact cell, and its full English name is BackContact. The BC structure can be combined with TOPCon and HJT, and has good compatibility. The innovative design of the BC cell lies in its unobstructed structure on the front. This feature eliminates the light energy loss caused by traditional grid line obstruction, ensures the maximum utilization of incident photons, and makes the BC cell conversion efficiency higher. It is the research focus of the next generation of mass-produced cells. At the same time, the unique design of the BC cell enables the electrodes of the emission region and the base region to be located on the back, thereby achieving the effect of no grid line obstruction on the front. This innovative feature makes it particularly suitable for use in scenarios of photovoltaic building integration, as well as in the household field with relatively low price sensitivity, and has broad market prospects.
[0003] The positive and negative electrodes of traditional BC batteries are distributed on the back and arranged in an interdigitated shape, such as Figure 1 As shown; the same type of electrode is connected by multiple main grids, such as Figure 2 As shown, welding points are left on the main grid, and silver paste is printed on the corresponding positive electrode area 1 or negative electrode area 2 by screen printing for both the main grid and the fine grid, and metallization is completed by sintering or auxiliary laser sintering to form a metallized electrode 3, so that the current generated by the battery can be led out. However, it is obvious that the electrode structure pattern arranged in a forked shape is complicated to make, and more silver paste is used when preparing the metallized electrode 3, which has a high production cost. Utility Model Content
[0004] In order to overcome the defects of the prior art BC battery electrode structure with interdigitated arrangement, such as complex graphic structure and high production cost.
[0005] In view of at least one of the above technical problems, the utility model provides an electrode structure of a back contact battery, directly manufacturing the P region and the N region in parallel and spaced arrangement, eliminating the main grid, and manufacturing fine grids on the P region and the N region. The structural improvement of only fine grids without main grids makes the manufacturing process simple; and since there is no main grid, metal composite is reduced, and the efficiency can be further improved. The specific technical solutions are as follows:
[0006] A back contact battery electrode structure is provided. The back of the back contact battery is provided with straight strip-shaped P region and N region, the P region and the N region are distributed in parallel and spaced apart; a positive electrode fine grid line is provided on the P region; a negative electrode fine grid line is provided on the N region.
[0007] In some embodiments of the present disclosure, the positive electrode fine gate wire includes a seed layer, and an electrode sheet is prepared on the seed layer; the negative electrode fine gate wire also includes a seed layer, and an electrode sheet is also prepared on the seed layer.
[0008] In some embodiments of the present disclosure, the seed layer is at least one of a silver paste layer, a nickel plating layer, or a transparent conductive oxide film.
[0009] In some embodiments of the present disclosure, the thickness of the seed layer is 1 nm to 5 μm.
[0010] In some embodiments of the present disclosure, the width of the seed layer is 3 μm to 30 μm.
[0011] In some embodiments of the present disclosure, the electrode sheet is a metal wire, and the material is one of pure copper, tin-plated copper, silver-plated copper or aluminum wire.
[0012] In some embodiments of the present disclosure, the width of the electrode sheet is not greater than the width of the seed layer.
[0013] In some embodiments of the present disclosure, the thickness of the electrode sheet is 2 μm to 10 μm.
[0014] Compared with the prior art, the electrode structure of the back contact battery has the following beneficial effects:
[0015] The technical solution eliminates the main grid by directly making parallel and spaced straight P regions and straight N regions on the back side of the back contact battery, and makes fine grid lines on the P region and the N region. The structural improvement of only fine grid lines without main grid simplifies the manufacturing process. In addition, since there is no main grid, metal recombination is reduced, which can further improve the efficiency and provide a new technical idea for the electrode structure design of BC batteries. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the layout of the P region and N region of the existing interdigitated BC battery;
[0017] Figure 2 A schematic diagram of the metallized electrode layout of an existing interdigitated BC battery;
[0018] Figure 3 It is a schematic diagram of the electrode structure in the utility model;
[0019] Explanation of the numbers in the figure: 1, positive electrode region; 2, negative electrode region; 3, metallized electrode; 4, P region; 5, N region. DETAILED DESCRIPTION
[0020] In order to better understand the purpose, structure and function of the utility model, the technical solutions in the embodiments of the utility model will be clearly and completely described below. It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the directional terms "upper" and "lower" is based on the positional relationship when the back of the BC battery is facing up, which is only for the convenience of description, and does not indicate or imply that the device or unit referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0021] As shown in the attached figure Figure 3 As shown, an electrode structure of a back-contact battery is designed, and a straight P region 4 and an N region 5 are prepared on the back of the back-contact battery. The P region 4 and the N region 5 are distributed in parallel and spaced apart, and can be evenly distributed in parallel and spaced apart, or can be distributed in unequal widths; a positive electrode fine grid line is prepared on the P region 4; a negative electrode fine grid line is prepared on the N region 5, and the positive electrode fine grid line and the negative electrode fine grid line are both located inside the BC battery sheet. This technical solution eliminates the main grid of the traditional BC battery by directly making a parallel and spaced straight P region 4 and a straight N region 5 on the back of the back-contact battery, and makes fine grid lines on the P region 4 and the N region 5. The structural improvement of only fine grid lines without main grids makes the manufacturing process simple; and since there is no main grid, metal composite is reduced, which can further improve the efficiency, increase the opening voltage by 2mV, increase the FF by 0.5, and improve the efficiency by more than 0.2%.
[0022] Among them, the positive electrode fine gate line includes a seed layer, and an electrode sheet is prepared on the seed layer; the negative electrode fine gate line also includes a seed layer, and an electrode sheet is also prepared on the seed layer, and the seed layer covers the upper surface of the P region 4 or the N region 5; the seed layer is at least one of a silver paste layer, a nickel plating layer or a transparent conductive oxide film, and can also be other metal plating layers; the thickness of the seed layer is 1nm~5μm; the width of the seed layer is 3μm~30μm; the electrode sheet is a metal wire, and the material is one of pure copper, tin-plated copper or silver-plated copper; the width of the electrode sheet is not greater than the width of the seed layer; the thickness of the electrode sheet is 2μm~10μm.
[0023] It can be understood that the above description is only for illustrating the specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the disclosure scope of the present application.
Claims
1. An electrode structure of a back contact battery, characterized in that: The back side of the back contact battery is provided with a straight P region (4) and an N region (5), wherein the P region (4) and the N region (5) are arranged in parallel and spaced apart; a positive electrode fine grid line is provided on the P region (4); and a negative electrode fine grid line is provided on the N region (5).
2. The electrode structure of the back contact battery according to claim 1, characterized in that: The positive electrode fine grid line includes a seed layer, and an electrode sheet is prepared on the seed layer; the negative electrode fine grid line also includes a seed layer, and an electrode sheet is also prepared on the seed layer.
3. The electrode structure of the back contact battery according to claim 2, characterized in that: The seed layer is at least one of a silver paste layer, a nickel plating layer or a transparent conductive oxide film.
4. The electrode structure of the back contact battery according to claim 3, characterized in that: The seed layer has a thickness of 1 nm to 5 μm.
5. The electrode structure of a back contact battery according to claim 3 or 4, characterized in that: The width of the seed layer is 3 μm to 30 μm.
6. The electrode structure of the back contact battery according to claim 5, characterized in that: The electrode sheet is a metal wire, and the material is one of pure copper, tin-plated copper, silver-plated copper and aluminum wire.
7. The electrode structure of the back contact battery according to claim 6, characterized in that: The width of the electrode sheet is not greater than the width of the seed layer.
8. The electrode structure of the back contact battery according to claim 4, characterized in that: The thickness of the electrode sheet is 2 μm to 10 μm.