| dc.description.abstract | With the rapid growth of the solar energy industry, the large amount of end-of-life solar modules will cause negative environmental impacts. Recycling of end-of-life solar modules will become a critical issue for next decade. Many components in solar modules can be recycled, and the current recycling methods mostly focus on purification and extraction of valuable elements. Although this method can effectively recycle waste, it often requires high-temperature heat treatment and corrosive liquids. It may cause secondary pollution to the environment, so it is necessary to develop an environmentally friendly recycling method. At present, the solar modules on the market are dominated by silicon, and silicon is regarded as a promising anode material for lithium-ion battery. Therefore, this research focuses on reusing solar cells of waste solar modules, which is different from the previous purification. Based on this concept, we select the wet ball milling method to prepare Si/SiOx/Al2O3 composite material, and further form a composite anode with a carbon paper substrate for lithium-ion battery. This experiment explores the influence of different ball milling time and different rotation speed on Si/SiOx/Al2O3, and the best parameters are defined. According to the results, the agglomeration is more serious and the oxidation degree is increased with increasing ball milling time or rotation speed. The composite electrode treated at 500 rpm for 2 hours exhibits discharge capacity of 1423 mAh/g with 74.5% capacity retention after 100 cycles at 200 mA/g. Even at 2000 mA/g, it still deliver discharge capacity of 866 mAh/g.
In addition, this work further study the influence of the modified carbon paper substrate on the electrochemical performance of composite anode. The analysis results show that the carbon paper containing nitrogen functional groups can further improve the electrochemical performance. After 100 cycles, the discharge capacity and capacity retention rate are increased to 1603 mAh/g and 90.6%, respectively. It indicates the nitrogen doping can increase the electrochemical stability and discharge capacity of the composite anode during cycling. Overall, this study demonstrates that waste solar cells can be transformed to Si/SiOx/Al2O3 composite materials directly through a simple and environmentally-friendly process. In addition, CF-based Si/SiOx/Al2O3 composite exhibits favorable performance in terms of cycling stability and rate capability. | en_US |