The unique micro-sized (2–10µm) Si/C composites consisting of 20nm carbon coated secondary Si were synthesized from the abundant and low cost Al–Si alloy ingot by acid etching, ball-milling and carbonization procedure. The nano-porous Si/C composites provide a capacity of 1182mAhg−1 at a current density of 50mAg−1, 952mAhg−1 at 200mAg−1, 815mAhg−1 at 500mAg−1, and maintain 86.8% of initial capacity after 300 cycles. Even at a much higher current density of 10A/g, the porous Si/C anode can still provide capacities of >200mAhg−1. Its superior rate capability and cycling stability of micro-sized nano-porous Si/C anodes is because it takes advantage of both long cycle life of nano-Si and high volumetric/gravimetric capacity of micro-Si. The hierarchical porous micro-scale Si/C with the carbon coating can stabilize the SEI layer and the inside pore provides adequate space for Si expansion, relaxing the stress/strain. The hierarchical Si/C with exceptional electrochemical performance is prepared by a simple, low-cost and saleable synthesis method, making it very promising for a large-scale production of high-performance Si-based anode materials in high-energy lithium-ion batteries.