Facile and scalable synthesis of Si@Void@C–graphite anodes from cost-effective micron-sized Si with optimized carbon coating toward high-performance lithium-ion batteries

Silicon (Si) is considered a promising anode material for lithium-ion batteries (LIBs) owing to its high theoretical specific capacity; however, its practical application is limited by its low electrical conductivity and severe volume changes during cycling. Herein, a facile, cost-effective and scalable strategy is reported to convert inexpensive micron-sized Si into a Si@Void@C-Graphite composite anode. This work reports statistically guided Taguchi optimization for tuning carbon-coating parameters to achieve maximum reversible capacity in micron-sized Si. The material is synthesized via high-energy mechanical milling, followed by Taguchi-optimized glucose-derived carbon coating, controlled NaOH etching to generate void regions within the carbon-coated Si particles and graphite incorporation to enhance electrical conductivity and structural stability. The optimized anode exhibits enhanced electrochemical performance, delivering a reversible capacity of 735 mAh/g after 600 cycles at 0.3 A/g and demonstrating 83% capacity recovery when the current density is reduced from 4 A/g to 0.15 A/g. This approach emphasizes statistical optimization and industrial feasibility, offering a practical framework for developing durable Si-based anodes.