US-12626835-B2 - Conductive silver aluminum paste, method for preparing the same, and electrode using the same

US12626835B2US 12626835 B2US12626835 B2US 12626835B2US-12626835-B2

Abstract

The present invention discloses a conductive silver aluminum paste, a preparation method, an electrode, and an N-type Topcon battery. The conductive silver aluminum paste comprises silver powder, metal powder containing aluminum element, powder containing silicon or boron element, glass powder, and organic carrier; wherein, when defining the total weight of the conductive silver aluminum paste as 100%, the weight percentage content of each component is: silver powder 80.0%-90.0%, metal powder containing aluminum element 0.5%-3.0%; powder containing silicon or boron element 0.1%-1.0%; glass powder 1.5%-6.0%; organic carrier 7.0%-15.0%. The present invention meets requirements for electrode materials of current development of N-type Topcon batteries well, and has advantages of low contact resistances, high open circuit voltages, high photoelectric conversion efficiency, and high output power.

Inventors

Xiaolong Chen
Jie Liu
Can Ma
Li Zhang
HONGXIA RAN
Bing Liu
TIAN YUE
Xiang Wang

Assignees

Shanghai Silver Paste Sci. & Tech. Co., Ltd.

Dates

Publication Date: 20260512
Application Date: 20230630
Priority Date: 20230320

Claims (1)

1 . A method for preparing a conductive silver aluminum paste, comprising the following steps: preparing glass powder: weighing raw materials used in glass powder according to a preset ratio; mixing them; after melting them at a high temperature, cooling them down, and drying them, through a crushing process, obtaining required glass powder; preparing organic carrier: weighing raw materials used in organic carrier according to a preset ratio; heating, stirring, and mixing them; dispersing them uniformly through high-speed centrifugation, and then filtering them to obtain organic carrier; preparing conductive silver aluminum paste: adding silver powder, metal powder containing aluminum element, powder containing silicon or boron element, and prepared glass powder into prepared organic carrier respectively according to a mass ratio, mixing them and stirring them uniformly, and then grinding them, adjusting their viscosity, and filtering them to obtain conductive silver aluminum paste; wherein, when defining the total weight of the conductive silver aluminum paste as 100%, the weight percentage contents of the components are: silver powder 80.0%-90.0%, metal powder containing aluminum element 0.5%-3.0%; powder containing silicon or boron element 0.1%-1.0%; glass powder 1.5%-6.0%; organic carrier 7.0%-15.0%.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present disclosure claims priority of Chinese patent application No. 202310270595.1 filed on Mar. 20, 2023. The entire contents of the above-identified applications are incorporated herein by reference. TECHNICAL FIELD The present invention belongs to the field of silicon solar cells, and in particular, relates to a conductive silver aluminum paste, a preparation method, an electrode, and an N-type Topcon battery. BACKGROUND With increasing shortage of fossil energy and increasing prominent of environmental pollution, problems caused by climate warming are more and more prominent. Sustainable development of new pollution-free energy projects has been widely and deeply studied in various countries. Solar cells are effective tools for converting light energy into electric energy by using photovoltaic effect, so they have also been developed rapidly in recent years, and photoelectric conversion efficiency of solar cells has also been greatly improved. With advancement of technology, the mainstream of solar cells in the market has gradually shifted from polycrystalline silicon cells and Perc single crystal cells to Se-perc single crystal cells and N-type Topcon cells at present. Among them, since Se-perc single crystal batteries have developed earlier than N-type Topcon batteries, their current technology is more mature. However, their drawbacks are also more obvious than that of N-type Topcon batteries. With gradual maturity of technology, improvement of photoelectric conversion efficiency of Se-perc single crystal batteries gradually becomes narrow. Affected by material intrinsic characteristics of short lifetime of P-type silicon minority carriers and large photo induced attenuation, further improvement of photoelectric conversion efficiency of Se-perc single crystal batteries is severely restricted. In order to pursue further improvement of photoelectric conversion efficiency of batteries, N-type Topcon batteries with a higher theoretical limit of photoelectric conversion efficiency have been widely studied and have achieved phased success. As a result, in recent years, there has been a transitional stage in which Se perc single crystal batteries gradually develop towards N-type Topcon batteries with higher efficiency, and various large battery production companies have quickly established their own N-type Topcon battery production lines. Therefore, new N-type Topcon batteries will eventually replace current mainstream P-type Se perc single crystal batteries and become a new mainstream of batteries. However, due to short and rapid development time of N-type Topcon batteries, technology development of electrode materials (conductive silver aluminum paste) that match them has not been fully mature, resulting in a significant impact on output power of N-type Topcon batteries. Therefore, developing a kind of conductive silver aluminum paste with high photoelectric conversion efficiency and high output power has important application value and economic value. SUMMARY OF THE DISCLOSURE The purpose of the present invention is to provide a conductive silver aluminum paste, a preparation method, an electrode, and an N-type Topcon battery; wherein, glass powder with good corrosion effect and wide sintering window is introduced and can adapt to sintering processes of wider N-type Topcon batteries; metal powder containing aluminum element with specific particle sizes and an appropriate amount is introduced and promotes formation of P++ junctions during sintering of silver aluminum paste, thereby increasing diffusion ability of minority carriers and increasing an open circuit voltage; by introducing an appropriate amount of antioxidants containing silicon or boron element powder, oxidation of silver powder and aluminum powder is reduced, and a sintering window difference between metal powder containing aluminum element and silver powder is balanced, further improvement of open circuit voltages of N-type Topcon batteries is realized, thereby achieving N-type Topcon monocrystalline silicon battery electrodes and electronic devices with low contact resistances, high open circuit voltages, high photoelectric conversion efficiency, and high output power. In order to achieve the above purposes, the present invention adopts technical solutions as follows. The present invention provides a conductive silver aluminum paste comprising silver powder, metal powder containing aluminum element, powder containing silicon or boron element, glass powder, and organic carrier; wherein, when defining the total weight of the conductive silver aluminum paste as 100%, the weight percentage contents of the components are: silver powder 80.0%-90.0%, metal powder containing aluminum element 0.5%-30.0%; powder containing silicon or boron element 0.1%-1.0%; glass powder 1.5%-6.0%; organic carrier 7.0%-15.0%. Furthermore, the silver powder is spherical and has a particle size of 0.2 μm˜4.5 μm and a D50 of