Constructing LiF-Enriched Solid Electrolyte Interface on Graphene Arrays with Abundant Edges on Microscale Si-C Anodes Toward High-Energy Lithium-Ion Batteries

Silicon (Si) anodes offer excellent lithium storage capacity for lithium-ion batteries but face practical limitations due to significant volume expansion and low intrinsic electrical conductivity. These issues lead to side reactions that consume the electrolyte and impede ion-electron transport, resulting in low areal loading (<2 mg cm⁻²) and restricted energy density. To address this, a scalable method is developed using spray drying of commercial graphite flakes (s-Gr) and nanosilicon particles (n-Si), followed by chemical vapor deposition to create microscale Si/C anodes (s-Gr/n-Si/VGs). Thin vertical graphene nanosheets (VGs) are grown on the surfaces and within the internal pores, forming a robust, micron-sized Si/C spherical composite material. The VGs construct the conductive network, allowing the electrodes to operate at high areal loadings without pulverization and promoting LiF-enriched solid electrolyte interphase for improved cycling stability. The s-Gr/n-Si/VGs maintain a capacity of 641.9 mAh g⁻¹ after 1000 cycles at 11.0 mg cm⁻², retaining 95.9% capacity. In pouch cells with NCM811 cathodes, the 5.0 Ah-level cells achieved 80.0% capacity retention after 510 cycles at 1.0 C. This research provides a feasible pathway for manufacturing high-performance, low-cost, and scalable Si/C anodes suitable for high-energy-density lithium-ion batteries.