With the growing demand for high-energy-density and long-lifespan lithium-ion batteries (LIBs), silicon/graphite composites have emerged as promising anode materials, as they synergize the ultrahigh capacity of silicon (Si) and the structural stability of carbon. To address the intrinsic volume variation issue of silicon, this work demonstrates a scalable and environmentally benign synthesis of micron-sized porous silicon/graphite composites (NGT-pSi/C) via the integration of FeCl 3 -etched spherical porous silicon (pSi) and waste-derived natural graphite tailings (NGT). The as-prepared NGT-pSi/C features a watermelon-like multi-core–shell architecture. The pores in pSi effectively accommodate the large volume expansion during cycling. Meanwhile, the upcycled NGT form a conductive layer to disperse mechanical stress, and the glucose-derived carbon layer constructs a conductive network. This waste-to-wealth approach enables the conversion of industrial byproducts into high-performance LIB anode materials. Comprehensive physicochemical and electrochemical characterizations reveal that abundant pores and continuous conductive networks in NGT-pSi/C synergistically mitigate Si pulverization, suppress interfacial degradation and enhance charge transfer kinetics. The NGT-pSi/C anode delivers exceptional cycling stability (591.2 mAh g −1 after 400 cycles at 0.5 A g −1 ) and superior rate capability. Furthermore, full cells paired with NCA90 (LiNi 0.9 Co 0.05 Al 0.05 O 2 ) cathodes maintain 72.6% of their initial capacity after 800 cycles. The corresponding pouch cell exhibits a high discharge capacity of 0.7 Ah and retains 74.43% capacity after 500 cycles. This practical strategy achieves a cost-performance synergy. Overall, by using near-zero-cost graphite waste and adopting a non-acidic etching process, this work establishes a sustainable and economically viable pathway for the scalable production of high-performance Si-based anodes. A sustainable strategy valorizes natural graphite tailings into porous Si-based NGT-pSi/C anodes. The 0.7 Ah NGT-pSi/C//NCA90 pouch cell retains 74.43% initial capacity over 500 cycles at 0.5 C and powers commercial mobile phones. • A sustainable "waste-to-wealth" strategy is developed via upcycling natural graphite tailings (NGT) and non-acidic FeCl 3 -etched porous Si, enabling eco-friendly scalable synthesis. • Watermelon-like multi-core–shell architecture mitigates Si volume expansion and forms a dual-conductive network, delivering 591.2 mAh g -1 after 400 cycles (0.5 A g −1 ) and excellent rate capability. • Electrochemical kinetics (GITT, EIS) and morphological characterizations confirm enhanced Li + diffusion, charge transfer, and electrode integrity from hierarchical porous and conductive structures. • NGT-pSi/C//NCA90 full cells (72.6% retention after 800 cycles) and pouch cells (74.43% retention over 500 cycles) show practicality, validated by mobile phone powering. • This scalable route balances high performance, low cost, and environmental friendliness, compatible with industrial production.
Zhang et al. (Sun,) studied this question.