CR2477 battery.Component technology updates and iterates, who will stand out on the road to efficiency?

　　Improving product efficiency is the ultimate goal of technological development. After experiencing the turmoil of May 31 last year, reducing the cost of electricity through technological improvements has become an urgent matter for the photovoltaic industry. Analyzing each link in the photovoltaic industry chain, the polycrystalline silicon material link places more emphasis on process stability rather than technological innovation; in the battery link, the popularity of PERC has enabled the cell efficiency to reach 22.5%. New technologies such as HIT and IBC are still difficult to challenge in terms of efficiency and cost. PERC. In the component sector, due to the continuous decline in cell prices and the weak price elasticity of component auxiliary materials, there is currently a lot of room for innovation in the development of component technology. At the SNEC exhibition that just passed this year, new module technologies such as half-cut, shingled, panel interconnection, and splicing emerged one after another. The 72-piece modules of first-tier companies generally exceeded 400W, and the high-efficiency era of 4.0 is gradually coming. 1. Efficiency improvement and loss reduction The realization of component efficiency is nothing more than starting from two directions: improving efficiency and reducing losses. First of all, eliminating blank spaces and increasing the filling volume of battery cells is the most direct way to increase the power of components. From the perspective of eliminating spacing, shingling technology has been widely used in the market in recent years. From a structural point of view, the shingled technology is to slice the battery sheets and directly connect them into strings with conductive glue, so that there is no gap between the front and rear batteries. In the same area, shingled modules can accommodate more than 6% more cells than conventional modules. This laminated connection method also enables shingled components to have better mechanical load and fewer cracks than traditional components. At the same time, the superposition of shingled technology and high-efficiency battery technology can also significantly improve module efficiency. Seraphim's double-sided eclipse module uses both shingled and HIT battery technologies, and the module power reaches 500W. WeChat picture_20190619174911 But judging from the current trend, shingling is not the only technical route to eliminate the distance between cells. At this year's SNEC exhibition, we saw many new ideas. For example, Haitai's Taishan series modules use plate interconnection technology. The module is composed of two plates connected in series to form a circuit. There is no gap between the longitudinal modules of the module, and the high-density filling process of the battery cells is comparable to that of tiles. WeChat Picture_20190619175015 However, whether it is shingling or plate interconnection, there is still a certain loss problem. Panel interconnect components still use solder ribbons for connection, while the mainbar-free design of shingled components reduces metal shading, but there is an unavoidable loss problem in the conductive adhesive connecting the cells. At the same time, the stacked connection also causes waste in blocking some cells. 2. The innovative splicing technology of splicing components cleverly solves the technical difficulties of soldering strips. The tile module is based on the traditional module packaging technology and replaces the string welding machine to achieve a significant reduction in the distance between the tiles, and ultimately achieves a packaging density comparable to that of shingled modules. On the one hand, the connection method of the cells in the patchwork module greatly reduces the distance between the cells. Since the welding ribbon generally has a certain thickness or height, this causes the welding ribbon itself to have a certain amount of stress that needs to be released. If the welding ribbon is thicker and the spacing between the pieces is small, it will bring the possibility of cracks to the component. In this regard, the spliced components apply double soldering strip technology, so that the cell spacing can be controlled within an accuracy of 0.4mm~0.6mm. Picture 1 On the other hand, the solder tape used in the patchwork assembly reduces the light shading rate to a minimum. Generally speaking, the loss of incident light caused by the shielding of the solder ribbon is inevitable, but the patchwork assembly does not use conventionally shaped solder ribbons during the welding process, but creatively uses triangular solder ribbons. After the incident light hits both sides of the triangle, it will be reflected to the cell. As a result, the solder ribbon can be perfectly "invisible" and achieve zero obstruction of the incident light. Picture 2: The splicing technology connects the battery sheets seamlessly and without overlapping. The white space in the module and the utilization rate of the battery sheets have reached a new height. In the case of relatively small area, the splicing component’s The power and efficiency are greater than conventional components, and the component efficiency can reach more than 20%. Generally speaking, since the light transmittance of photovoltaic glass is only 92%, the EVA film and the welding ribbon will also block or dissipate light. Therefore, after the cells are packaged, the module power will be less than the sum of the cell powers. This Part of the lost power is the "sealing loss" of the component. However, there is a "sealed overflow" situation in the patchwork components. On the one hand, the chip assembly adopts a half-chip packaging method, which means cutting the traditional battery sheet into two, thereby halving the current of the battery sheet, reducing the resistance, and reducing the thermal resistance loss. On the other hand, the reflection of the incident light by the triangular welding strip also recovers part of the loss. These two advantages make the module power greater than the sum of the power of the cells after the cells are packaged, which is equivalent to giving away some cells. Generally speaking, the wave of technological revolution continues to advance, and different types of technologies have their own strengths. However, with the deepening of applications and the screening of the market, only technologies with greater adaptability and higher cost performance can stay within the range of user choice for a long time.

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