Upcycling Discarded Photovoltaic Silicon into High-Performance Anode Material

Silicon has emerged as a highly promising anode material for next-generation lithium-ion batteries owing to its exceptional theoretical capacity. Giving discarded photovoltaic (PV) silicon a new life in silicon-based anode materials can avoid resource waste and achieve a leap in value. Herein, we propose a sustainable strategy for the valorization of PV waste silicon into a high-performance anode material. The porous spherical structure, constructed via spray drying, can effectively mitigate volume expansion during the cycling process while facilitating lithium-ion transport. An external carbon coating can further enhance electronic conductivity and suppress parasitic reactions at the silicon-electrolyte interface. As a result, the obtained spherical porous p-Si/C@C-100 anode delivers the capacities of 1075.4 and 834.4 mA h g^-1 after 300 and 345 cycles at 1 and 2 A g^-1, respectively. Thus, such a work underscores a critical role of rational porous engineering and robust carbon encapsulation in enabling fast-charging Si/C anodes, offering an economical and green pathway for recycling waste silicon from discarded solar cell panels.