Novel approaches to resource utilization in photovoltaic recycling: silicon-carbon anode materials

The rapid expansion of global photovoltaic (PV) deployment is generating a large and heterogeneous stream of silicon waste. Conventional recycling that re-melts feedstock back to solar-grade purity is energy intensive and economically strained, which limits sustainability. This review advances an alternative, value-retentive pathway that treats waste photovoltaic silicon (PV-Si) as a high-value precursor for lithium-ion battery (LIB) anodes, where the impurity spectrum can be engineered and interfacial chemistry can be programmed. We first map the resource attributes of PV-Si from distinct sources and show how selective purification coupled with multiscale structural design can convert native surface oxides and trace metals from liabilities into controllable variables for building stable electrode-electrolyte interfaces. From the evidence we derive transferable design rules that link multiscale architectural choices and process intensification to three mutually reinforcing targets, suppression of silicon volume change, creation of percolating ion and electron transport networks, and durable stabilization of the solid electrolyte interphase (SEI). On the basis of a critical appraisal of existing electrochemical reports, we argue that claims of practicality must be validated under stringent conditions that include thick electrodes with areal capacity greater than 3 mAh cm^-2, initial Coulombic efficiency (ICE) above 95%, and full cells paired with commercial cathodes. Finally, we call for the development of a data-centric verification framework and set an agenda for its creation, while advocating reproducible, comparable, and auditable protocols that span materials, processes, and devices. The proposed approach shortens the path from laboratory feasibility to pilot-scale deployment and offers a transferable paradigm for circular and upgraded reuse of other renewable-energy materials.