Waste‐Derived Onion‐Like Carbon Nanoparticles/Recycled Silicon Composite for Sustainable High‐Performance Lithium‐Ion Batteries

The sustainable fabrication of electrode materials using waste streams offers a promising pathway toward low‐cost and environmentally sustainable lithium‐ion batteries (LIBs). In this work, waste‐derived silicon (WD‐Si) recovered from end‐of‐life solar panels was used to fabricate a high‐performance Si/C composite anode. Waste rubber‐derived carbon nanoparticles (MWRC), synthesized through an energy‐efficient microwave‐assisted process, were incorporated as the carbon component. Mechanical milling was employed to reduce the particle size of WD‐Si, resulting in a broad particle‐size distribution with a significant submicron fraction after only 60 min of processing. Structural analyses confirmed that the milled Si retained high crystallinity while developing nanosized polycrystalline domains. Microwave‐assisted carbonization of waste rubber generated onion‐like carbon nanoparticles that were uniformly distributed along the rough surfaces and edges of the Si particles, forming a conductive and mechanically robust framework. The WD‐Si/MWRC composite exhibited significantly improved electrochemical performance compared with bare WD‐Si and commercial Si electrodes. The composite delivered initial discharge capacities of 2291.4, 1806.7, and 1280.1 mAh g ⁻¹ at 0.1, 0.2, and 0.5 C, respectively. After 50 cycles, the composite retained a reversible capacity of 663.8 mAh g ⁻¹ , whereas commercial Si retained only 242.8 mAh g ⁻¹ under the identical conditions.