A comprehensive review of photovoltaic silicon waste recycling: Characteristics, applications, and functional modification

With the rapid global transition toward renewable energy, the significant accumulation of photovoltaic silicon waste (PV–WSi) poses serious environmental and resource challenges. Sustainable recycling and valorization of PV–WSi offer a promising approach to this crisis, yet practical implementation is hindered by the inherent complexity of waste characteristics. This review comprehensively compares characteristics between silicon cutting waste (SCW) and retired silicon waste (RSW). Recent reuse applications and functional modification strategies are also outlined, including the closed–loop regeneration of purified silicon materials and valorization into advanced products (structural functional materials and environmental remediation materials). PV–WSi based anodes deliver an average capacity retention of 75.08%, demonstrating great potential for high–performance energy storage. Emphasis is placed on the underlying mechanisms of structural reconstruction and functionalization, exploring structural modifications and regeneration potential in correlation with waste characteristics. Additionally, life cycle assessment and economic analysis are employed to evaluate benefits of PV–WSi recycling routes, demonstrating their potential for circular economy. Future perspectives in the applications of PV–WSi recycling are also summarized, including machine learning integration, synergistic modification design and scale–up application, as well as environmental and economic performance balance. This work clarifies the characteristic–recycling relationship and further advances the synergistic development of energy sustainability and functional materials innovation.