阅读说明：本技术 一种薄化晶硅电池组件 (Thinned crystalline silicon battery pack ) 是由 严文生 臧月 王宇 吴秋轩 于 2021-07-23 设计创作，主要内容包括：本发明公开了一种薄化晶硅电池组件,本发明的电池组件包括抗反射玻璃、EVA薄膜、电池片组、TPT薄膜和铝框,所述的抗反射玻璃设置在EVA薄膜上方,EVA薄膜设置在电池片组上方,电池片组设置在TPT薄膜上方,所述的抗反射玻璃、EVA薄膜、电池片组、TPT薄膜通过铝框包围,其中抗反射玻璃顶面低于铝框的顶面；所述的电池片组由多个薄化晶硅电池串接组成；发明结构简单,提高了输出功率,尤其在光照入射角0-30度范围内具有明显提高输出功率的效果。本发明对晶硅电池未来走向薄化以及薄化晶硅电池组件功率提升提供了有意义的指导。(The invention discloses a thinned crystalline silicon battery assembly, which comprises antireflective glass, an EVA (ethylene vinyl acetate copolymer) film, a battery piece group, a TPT (thermoplastic vulcanizate) film and an aluminum frame, wherein the antireflective glass is arranged above the EVA film, the EVA film is arranged above the battery piece group, the battery piece group is arranged above the TPT film, the antireflective glass, the EVA film, the battery piece group and the TPT film are surrounded by the aluminum frame, and the top surface of the antireflective glass is lower than the top surface of the aluminum frame; the battery piece group is formed by connecting a plurality of thinned crystalline silicon batteries in series; the invention has simple structure, improves the output power, and has the effect of obviously improving the output power especially in the range of the illumination incidence angle of 0-30 degrees. The invention provides meaningful guidance for thinning the crystalline silicon battery in the future and improving the power of the thinned crystalline silicon battery component.)

1. A thinned crystalline silicon cell assembly, characterized by: the cell assembly comprises antireflective glass, an EVA film, a cell stack, a TPT film and an aluminum frame, wherein the antireflective glass is arranged above the EVA film, the EVA film is arranged above the cell stack, the cell stack is arranged above the TPT film, the antireflective glass, the EVA film, the cell stack and the TPT film are surrounded by the aluminum frame, and the top surface of the antireflective glass is lower than that of the aluminum frame; the battery piece group is formed by connecting a plurality of thinned crystalline silicon batteries in series;

each thin crystal silicon cell comprises a first SiN from top to bottom in sequence_xFilm, SiO₂Passivation film, p-type monocrystalline silicon wafer, and Al₂O₃Thin film, second SiN_xFilm and first SiO_xA film; texturing the upper surface of the p-type monocrystalline silicon piece, forming an n + emitter by the p-type monocrystalline silicon to obtain a p-n junction, wherein the doping concentration of the n + emitter is (1.0 +/-0.2) multiplied by 10¹⁸The method comprises the following steps that (1) the back surface of a p-type monocrystalline silicon wafer is drilled by laser, a p + local back surface field is formed in the hole, and an aluminum metal contact is arranged; the upper surface of the p-type monocrystalline silicon piece is provided with a selective emitter junction, and the emitter junction is provided with a metal electrode; the thickness of the first SiNx film is 60-75 nanometers and SiO₂The thickness of the passivation film is 8-10 nanometers, the thickness of the p-type monocrystalline silicon piece is 100-150 meters, and Al₂O₃The film thickness is 8-10 nm, and the second SiN_xThe film thickness is 30-40 nm, the first SiO_xThe thickness of the film is 80-250 nm.

2. A thinned crystalline silicon cell assembly as claimed in claim 1, wherein: the thinned crystalline silicon battery alsoComprising a second SiO_xA film; wherein the second SiO_xA thin film arranged on the first SiN layer_xAbove the film; the second SiO_xThe thickness of the film is 40-45 nm.

3. A thinned crystalline silicon cell assembly as claimed in claim 1, wherein: the thickness of the anti-reflection glass is 2.2mm, wherein the thickness of the anti-reflection layer is 110 nm.

4. A thinned crystalline silicon cell assembly as claimed in claim 1, wherein: the thickness of the EVA film is 0.45 mm.

5. A thinned crystalline silicon cell assembly as claimed in claim 1, wherein: the vertical section of the aluminum frame is L-shaped, wherein the length of the vertical part is 4cm, the width of the vertical part is 1.1cm, the width of the horizontal part is 0.2cm, and the length of the horizontal part is 3 cm; wherein the height of the top surface of the thickness of the anti-reflection glass from the top surface of the aluminum frame is 0.3 cm.

Technical Field

The invention relates to the field of batteries, in particular to a thinned crystalline silicon battery assembly.

Background

The crystalline silicon solar cell occupies 95% of the global photovoltaic market by the unique advantages of abundant earth crust raw material reserves, no toxicity, high device stability and the like. At present, the mainstream product in the crystalline silicon photovoltaic industry is a PERC battery, and the typical thickness of an adopted silicon wafer is about 180 micrometers. Commercial crystalline silicon PERC cells will go towards flaking according to international photovoltaic technology roadmap prediction. In the next seven years, the thickness of the crystalline silicon gradually decreases to 150 microns. The benefit is to reduce the cost of the cell because the cost of the crystalline silicon material is 65% higher than the cost of the cell. For photovoltaic solar applications, it is common to use the form of a module, i.e. consisting of a plurality of monolithic cells. However, with current commercial battery technologies, thinning of the battery sheet causes a reduction in battery conversion efficiency and output power of the battery assembly, which is not cost effective.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for improving the output power of a thinned crystalline silicon cell assembly.

A thinned crystalline silicon battery assembly comprises antireflection glass, an EVA (ethylene vinyl acetate) film, a battery piece group, a TPT (thermoplastic vulcanizate) film and an aluminum frame, wherein the antireflection glass is arranged above the EVA film, the EVA film is arranged above the battery piece group, the battery piece group is arranged above the TPT film, the antireflection glass, the EVA film, the battery piece group and the TPT film are surrounded by the aluminum frame, and the top surface of the antireflection glass is lower than that of the aluminum frame; the battery piece group is formed by connecting a plurality of thinned crystalline silicon batteries in series;

each thin crystal silicon cell comprises a first SiN from top to bottom in sequence_xFilm, SiO₂Passivation film, p-type monocrystalline silicon wafer, and Al₂O₃Thin film, second SiN_xFilm and SiO_xA film; texturing the upper surface of the p-type monocrystalline silicon piece, forming an n + emitter by the p-type monocrystalline silicon to obtain a p-n junction, wherein the doping concentration of the n + emitter is (1.0 +/-0.2) multiplied by 10¹⁸A/cm 3, p-type monocrystalline silicon wafer back faceDrilling by using laser, forming a p + local back surface field in the hole, and arranging an aluminum metal contact; the upper surface of the p-type monocrystalline silicon piece is provided with a selective emitter junction, and the emitter junction is provided with a metal electrode; the first SiN_xThe thickness of the film is 60-75 nanometers and SiO₂The thickness of the passivation film is 8-10 nanometers, the thickness of the p-type monocrystalline silicon piece is 100-150 microns, and Al is₂O₃The film thickness is 8-10 nm, and the second SiN_xThe thickness of the film is 30-40 nm, SiO_xThe thickness of the film is 80-250 nm.

Preferably, the thinned crystalline silicon cell further comprises a first SiO_xA film; wherein the first SiO_xA thin film arranged on the first SiN layer_xAbove the film; the first SiO_xThe thickness of the film is 40-45 nm.

Preferably, the thickness of the anti-reflection glass is 2.2mm, wherein the thickness of the anti-reflection layer is 110 nm.

Preferably, the thickness of the EVA film is 0.45 mm.

Preferably, the vertical section of the aluminum frame is L-shaped, wherein the length of the vertical part is 4cm, the width of the vertical part is 1.1cm, the width of the horizontal part is 0.2cm, and the length of the horizontal part is 3 cm; wherein the height of the top surface of the thickness of the anti-reflection glass from the top surface of the aluminum frame is 0.3 cm.

Compared with the prior art, the invention has the following effects: the invention has simple structure, improves the output power, and has the effect of obviously improving the output power especially in the range of the illumination incidence angle of 0-30 degrees. The invention provides meaningful guidance for thinning the crystalline silicon battery in the future and improving the power of the thinned crystalline silicon battery component.

Drawings

FIG. 1 is a schematic diagram of a cell according to the present invention;

FIG. 2 is a schematic diagram of a thinned crystalline silicon cell assembly;

FIG. 3 is a diagram of a thinned crystalline silicon cell assembly in relation to an aluminum frame;

fig. 4 is a circuit diagram of a 72-wafer thinned crystalline silicon cell assembly;

FIG. 5 is an I-V diagram of a thinned crystalline silicon cell assembly from simulation calculations;

fig. 6 is a graph of simulated output power dependence of light incident angle for a thinned crystalline silicon cell assembly conventional structure design and the present new design structure.

Detailed Description

As shown in fig. 2, a thinned crystalline silicon cell module includes an anti-reflection glass, an EVA film, a cell stack, a TPT film and an aluminum frame, wherein the anti-reflection glass is disposed above the EVA film, the EVA film is disposed above the cell stack, the cell stack is disposed above the TPT film, the anti-reflection glass, the EVA film, the cell stack and the TPT film are surrounded by the aluminum frame, and a top surface of the anti-reflection glass is lower than a top surface of the aluminum frame; the battery piece group is formed by connecting a plurality of thinned crystalline silicon batteries in series; the vertical section of the aluminum frame is L-shaped, wherein the length of the vertical part is 4cm, the width of the vertical part is 1.1cm, the width of the horizontal part is 0.2cm, and the length of the horizontal part is 3 cm; wherein the height of the top surface of the thickness of the anti-reflection glass from the top surface of the aluminum frame is 0.3 cm. The thickness of the anti-reflection glass is 2.2mm, wherein the thickness of the anti-reflection layer is 110 nm; the thickness of the EVA film is 0.45 mm. The parameter is W as shown in FIG. 3_f＝1.1cm,Z_f＝4cm，Z_l＝0.3cm，W_b＝1.9cm,Z_b＝0.2cm。

As shown in FIG. 1, each of the thinned crystalline silicon cells includes a first SiO in sequence from top to bottom_xThin film, first SiN_xFilm, SiO₂Passivation film, p-type monocrystalline silicon wafer, and Al₂O₃Thin film, second SiN_xFilm and second SiO_xA film; texturing the upper surface of the p-type monocrystalline silicon piece, forming an n + emitter by the p-type monocrystalline silicon to obtain a p-n junction, wherein the doping concentration of the n + emitter is (1.0 +/-0.2) multiplied by 10¹⁸/cm³Laser drilling is adopted on the back surface of the p-type monocrystalline silicon piece, a p + local back surface field is formed in the hole, and an aluminum metal contact is arranged; the upper surface of the p-type monocrystalline silicon piece is provided with a selective emitter junction, and the emitter junction is provided with a metal electrode; the thickness of the first SiNx film is 60-75 nanometers and SiO₂The thickness of the passivation film is 8-10 nanometers, the thickness of the p-type monocrystalline silicon piece is 100-150 microns, and Al is₂O₃The film thickness is 8-10 nm, and the second SiN_xThe thickness of the film is 30-40 nm，SiO_xThe thickness of the film is 80-250 nm.

The simulation calculation of the component performance adopts and combines two commercial scientific calculation software Quokka3 and Sunsolve with high credibility in the industry^TM. Quokka3 was used to calculate photovoltaic parameters for individual cells including short circuit density, open circuit voltage, fill factor, conversion efficiency. Quokka numerical value solves the problem of one-dimensional/two-dimensional/three-dimensional steady carrier transport in the quasi-neutral silicon device. It uses a so-called "conductive boundary" to account for the increased lateral conductivity in the near-surface region (e.g., diffusion or inversion layer) to simulate most silicon solar cell devices without significant loss of generality.

Sunsolve^TMIs used to calculate the I-V characteristic and output power of the battery pack. The method is based on ray tracing calculations. In the present calculation, we set that each calculation packet includes 5000 rays, and each operation is 5 × 10⁶Light rays bounce 10000 times per light ray. These parameter settings ensure a high reliability of the simulation results.

The I-V characteristics of the battery pack of the invention obtained by the simulation calculation are shown in FIG. 5. The sun starts and falls every day. For a fixed cell module, the output power generated is different for different solar radiation angles. Therefore, we also simulated and calculated the dependence of the output power of the battery assembly with the incident angle of light, see fig. 6, including both the conventional battery structure design and the new design structure. By contrast, on the one hand, it can be seen that both the conventional design and the new design produce the highest output power at an entrance angle of 0 degrees, 376 watts and 390 watts, respectively. At this time, the output power of the newly designed component is increased by 14 watts compared to the output power of the conventionally designed component. The effectiveness of the new structural design in improving the output power is shown. On the other hand, as seen from fig. 6, the output power of both components shows a tendency to decrease as the incident angle increases. Moreover, the output power difference of the two components is gradually reduced, and the main difference is reflected in the range of 0-30 degrees of the incident angle. This shows that the design module of the present invention has a significant effect of increasing the output power in the range of 0-30 degrees of the incident angle of illumination. The invention provides meaningful guidance for thinning the crystalline silicon battery in the future and improving the power of the thinned crystalline silicon battery component.

The connection distribution of the battery pieces is shown in fig. 4, the layout is 6 rows, and each row has 12 pieces; the transverse and longitudinal distances of the cell pieces are 0.4cm and 0.3cm respectively; the method is also suitable for various cell numbers such as 36, 48 and 60 cells and various cell distribution combinations.